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2837399 | Liquid container for gas humidification and liquid storage device | 1 | Based on the following detailed description of an invention, generate the patent claims. There should be 10 claims in total. The first, independent claim is given and the remaining 9 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | Embodiments are illustrated in the accompanying figures to improve understanding of concepts as presented herein. Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to others to facilitate understanding of the embodiments.
Since various aspects and embodiments are merely exemplary and not limiting, after reading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the invention. Other features and benefits of any one or more of the embodiments will be apparent from the following detailed description and the claims.
The use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. Accordingly, this description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
As used herein, the terms "comprises," "comprising," "includes," "'including," "has," "having" or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a component, structure, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such component, structure, article, or apparatus. Further, unless expressly stated to the contrary, the term "or" refers to an inclusive or and not to an exclusive or. For example, a condition "A or B" is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
As illustrated in Figure 1, an exemplary embodiment according to the present disclosure provides a liquid container 1 for humidifying gas and increasing gas humidity, wherein the gas may include air, pure gas or gas mixture, and the humidification may be, without limitation, carried out by heating, evaporation or ultrasonic atomization. The liquid container 1 mainly comprises two chambers, which are the first storage chamber 10 and the second storage chamber 20 disposed for example in the first storage chamber 10. Optionally, as shown in Figure 1, the liquid container 1 may also include a cover 30 covering the first storage chamber 10 and the second storage chamber 20.
The first storage chamber 10 has a reservoir primarily for holding liquid to be humidified, such as water, normal saline or the like. If humidification is carried out by heating, the liquid to be humidified may be heated and evaporated by a heating board, a heater, a heating plate, or the like installed at a certain position (e.g. heating zone 12) of the bottom 11 of the first storage chamber 10.
The second storage chamber 20 also includes a reservoir primarily for holding supplemental liquid such as water, normal saline or the like. The liquid within the second storage chamber 20 and the first storage chamber 10 may be the same or different. An opening 24 is formed on the second storage chamber 20 such as at the bottom, such that gas is allowed to enter the second storage chamber 20 via the opening 24 and cause air pressure change in the second storage chamber 20, and such that liquid in the second storage chamber 20 may flow downwardly via the opening 24 into the first storage chamber 10 so as to supplement the liquid amount in the first storage chamber 10. In addition, the second storage chamber 20 may be optionally equipped on its surface with an aerodynamic structure 28, such as fins of a certain shape, to regulate the time of gas staying in the liquid container 1 and its movement distance, or to define a path tor gas flow, for example.
Moreover, in this embodiment, the liquid container 1 also includes an optional cover 30. The cover 30 may be connected with the first storage chamber 10 to situate the second storage chamber 20 therebetween. In this case, gas entering the gas humidification space of the liquid container 1 via the gas inlet 32 may move along the gas flow path defined by the aerodynamic structure 28 and, after absorbing a certain amount of moisture, leave the gas humidification space of the liquid container 1 via the gas outlet 31, to a user's respiratory tract through a duct for example connected with the gas outlet 31.
As used herein, the term "connect," "connected," "connected to" or "connected with" means "combined, joined, linked or assembled together," and includes direct connection where no intermediate (e.g. a gasket or washer) exists and indirect connection where an intermediate exists between two elements to be connected. In addition, when different components are connected, these components may form an integral, one-piece structure such as by integration in which different components act as different parts of the integral structure, or these components may be distinct and separate components connected together. Unless otherwise specified, means for Joining distinct and separate components together includes interlocking, engagement, fastening, mortise and tenon joint, or any other connection means known and understood in the mechanical arts.
Accordingly, depending on the preferences in use and during manufacture, the first storage chamber 10 and the second storage chamber 20 can form an integral structure, or they can be separate and distinct structures assembled together. Similarly, the second storage chamber 20 and the cover 30 can form an integral structure, or they can be separate and distinct structures assembled together.
Figure 2 illustrates a cross-sectional view of a liquid storage device according to one embodiment of this invention. The liquid storage device 2 mainly comprises a first storage chamber 10, a second storage chamber 20 and a cover 30. As an outer chamber, the first storage chamber 10 defines a receiving space 13 therein, and as an inner chamber, the second storage chamber 20 is disposed within the receiving space 13, wherein the inner chamber defines inwardly a supplemental liquid storage space 27. In this embodiment, the second storage chamber 20 primarily consists of a top wall 21, a bottom wall 22 and a side wall 23 connected therebetween, preferably in an airtight manner. For example, the bottom wall 22 and side wall 23 of the second storage chamber 20 may form a unitary and integral structure, and the top wall 21 of the second storage chamber 20 may be removably covered on the side wall 23, such that the space defined collectively by the top wall 21, the bottom wall 22 and the side wall 23 is airtight with respect to and not in gas communication with the exterior except through the opening 24, as described below.
To form gas communication and liquid communication between the first storage chamber 10 and the second storage chamber 20, the second storage chamber 20 is provided with at least one opening 24 for example on the bottom wall 22, such that gas can enter the second storage chamber 20 and liquid can leave the supplemental liquid storage space 27 of the second storage chamber 20. As illustrated in Figure 2, the position of the opening 24 is above the bottom 11 of the first storage chamber 10, so liquid from the second storage chamber 20 will be driven naturally to flow downwardly into the first storage chamber 10.
In this exemplary embodiment, thee is only one opening 24 termed on the bottom wall 22 of the second storage chamber 20, so gas and liquid respectively enter and leave the space defined within the second storage chamber 20 via the same opening 24. In order to serve the dual purpose of gas entry and liquid exit, parameters of the opening 24 such as aperture size, shape and the so on can be designed without undue experimentation, such as in view of the cohesion force within liquid in the second storage chamber 20, hydraulic pressure, air pressure and the like. A circular opening may be used, for example, which has an aperture diameter ranging from 0.5 mm to 5 mm, but not limited thereto.
In order to further explain the concepts and principles behind this invention, the operational states of various embodiments with the presence of liquid are described with the accompanying drawings. However, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Figure 3 illustrates a cross-sectional view of an exemplary liquid storage device for gas humidification in an operational state. When in use, the second storage chamber 20 of the liquid storage device 2 can first be filled with liquid. The filling process may involve separating the top wall of the second storage chamber 20 from the side wall, filling the liquid into the supplemental liquid storage space 27, and then joining or connecting the top wall and the side wall in an airtight manner. Alternatively, a switchable liquid injection port may be formed on any desirable portion of the second storage chamber 20 for liquid injection, and after being filled with the liquid, the second storage chamber 20 may then be assembled between the cover 30 and the first storage chamber 10. Further alternatively, the second storage chamber 20 may be made as a disposable component, and the supplemental liquid storage space 27 is filled with the liquid In advance during production and then sealed airtight, such that the second storage chamber 20 can be mounted by uses without the additional liquid loading process. For example, the second storage chamber 20 may be placed into the receiving space of the first storage chamber 10, allowing liquid to flow into the first storage chamber 10 through the opening on the second storage chamber 20. Depending on the user's need, a predetermined amount of liquid may be loaded into the first storage chamber 10 before setting the second storage chamber 20.
In this embodiment, two openings 24a and 24b are formed on the bottom of the second storage chamber 20. A liquid flow pipe 26 is formed extending from the openings 24a downwardly, and the terminal orifice 26a of the liquid flow pipe 26 is above the bottom 11 of the first storage chamber 10. In addition, a gas flow pipe 25 is formed extending from the openings 24b downwardly. Two openings are used in this embodiment for allowing liquid to move from the second storage chamber 20 into the first storage chamber 10 and allowing gas to move from the first storage chamber 10 into the second storage chamber 20. However, the liquid or gas is not limited to entering or exiting trough a specific opening. In word words, when two or more openings are formed, each opening may serve for gas and/or liquid passage. In view of several factors including aperture size, opening shape, cohesion force within liquid, hydraulic pressure, air pressure and the like, different openings may be designed either with more tendency toward allowing gas to enter the second storage chamber 20 or with more tendency toward allowing liquid to leave the second storage chamber 20, and the size or shape of different openings may be the same or different. In this embodiment, for example, the openings 24a and 24b may individually have an aperture diameter from 0.5 mm to 5 mm, but not limited thereto.
As shown in Figure 3, the two openings are both extended downwardly to form the gas flow pipe 25 and the liquid flow pipe 26 respectively, and the length, the pipe diameter, and other parameters of the two pipes may be the same or different. For example, the length of the liquid flow pipe 26 may be greater than that of the gas flow pipe 25. In a situation where a plurality of pipes of differellt lengths are formed, the longer pipe sustains a greater pressure at the bottom end, so liquid has a greater tendency to flow from the longer pipe. In other words, a longer pipe, such as the liquid flow pipe 26 in this embodiment, is more suitable tor discharging liquid from the second storage chamber 20. However, as stated above, the liquid flow pipe 26 is not limited to serve as a passage for liquid discharge only but may also be useful for gas entry in some circumstances, and, similarly, the gas flow pipe 25 is not limited to serve as a passage for gas entry only but may also be useful for liquid discharge in some circumstances, both depending on various environmental parameters in operational states and the structural design of the second storage chamber 20. In this embodiment, for example, the length of the gas flow pipe 25 extending downwardly may be less than 10 mm, and the liquid flow pipe 26 may be 5 mm longer than the gas flow pipe 25, such as less man 15 mm, but not limited thereto.
In an operational state, gas primarily enters the second storage chamber 20 through the gas flow pipe 25, and liquid primarily enters the first storage chamber 10 from the supplemental liquid storage space 27 through the liquid flow pipe 26, such that the liquid level in the first storage chamber 10 gradually raises and that the liquid level in the supplemental liquid storage space 27 gradually lowers at the same time. When the liquid level in the first storage chamber 10 raises to the position of the orifice at the bottom of the gas flow pipe 25, before which the terminal orifice 26a of the liquid flow pipe 26 has been submerged by the liquid, the gas flow pipe 25 is sealed by the liquid, and gas is prevented from entering the second storage chamber 20 via the gas flow pipe 25 and causing pressure change, thus achieving a substantially balanced or steady state of the system within the liquid storage device 2. Accordingly, in an embodiment where a plurality of openings are employed, the position or height of the opening(s) primarily for gas entry can determine the liquid level in the thirst storage chamber 10 under the steady state, during which the space within the first storage chamber 10 is divided into two parks - the space below the opening terming a storage space for liquid to be heated (i.e. the space occupied by the liquid, as indicated by the numeral 14 in Figure 3 ), and the space above the opening forming a gas humidification space (i.e. the space occupied by the gas, as indicated by the numeral 15 in Figure 3 ).
During operation of a humidifier such as a heater or an atomiser, as shown in Figure 4, liquid in the storage space for liquid to be heated 14 will be evaporated or atomized and then be absorbed by the gas in the gas humidification space 15, which then leaves the liquid, storage device 2 from the gas outlet 31. Thus, during operation, the liquid level in the first storage chamber 10 will gradually lower, and when the gas flow pipe 25 is no longer sealed by the liquid, gas may re-enter the second storage chamber 20 via the gas flow pipe 25 and cause air pressure change in the second storage chamber 20 (i.e. air pressure increases due to the increasing gas amount), such that liquid may be driven to flow downwardly and leave the supplemental liquid storage space 27 via the liquid flow pipe 26, achieving the purpose of automatic supplement of liquid to the storage space tor liquid to be heated 14. Subsequently, the liquid level gradually raises again in the storage space for liquid to be heated 14, and the gas flow pipe 25 is sealed by the raising liquid level to block the gas entry into the second storage chamber 20 therefrom, thereby reaching the steady state mentioned above as illustrated in Figure 3. Therefore, when in use, the design of this embodiment can maintain a substantially constant amount of liquid in the first storage chamber 10.
While various stages during operation are described according to their temporal sequence, however, it is understood that, when in actual use, different stages may happen one after the other or almost at the same time. Therefore, during operation, the liquid storage device 2 is substantially maintained at a dynamic equilibrium or steady state until all the liquid in the supplemental Liquid storage space 27 is used up.
Figure 5 illustrates a cross-sectional view of a liquid storage device 2 according to another embodiment of this invention, in which the opening primarily for gas passage is penetrated by the gas flow pipe 25. The operational principle behind this embodiment is substantially the same as other embodiments. When the bottom opening of the gas flow pipe 25 is not sealed for example by liquid, gas enters the second storage chamber 20 via the gas flow pipe 25, and liquid in the supplemental liquid storage space 27 flows into the first storage chamber 10 through the liquid flow pipe 26. When the liquid level in the first storage chamber 10 raises to a predetermined degree, such as sealing the bottom opening of the gas flow pipe 25, gas is prevented from entering the second storage chamber 20 and inducing air pressure increase therein, and liquid flow is inhibited from the supplemental liquid storage space 27 into the first storage chamber 10. In addition, when the liquid level in the first storage chamber 10 lowers during gas humidification, gas can be allowed to enter the second storage chamber 20 via the gas flow pipe 25 again, and liquid is similarly allowed to flow from the supplemental liquid storage space 27 into the first storage chamber 10 again.
The present embodiment is characterized in that the gas flow pipe 25 penetrates into the second storage chamber 20 and that the top opening thereof is above the liquid level in the second storage chamber 20, such that the gas flow pipe 25 contains substantially no liquid therein. Thus, when entering the second storage chamber 20 via the gas flow pipe 25, gas will not contact with liquid and will not form bubbles as shown in Figure 4, thereby reducing the voice or noise from the operating liquid storage device 2 caused by bursting bubbles, and making this embodiment particularly suitable for a situation which requires less noise, such as when a user is sleeping.
As mentioned above, in this invention, different components or structures may be formed as one piece or individually and separately formed and then assembled together. For example, suitable molds may be used to make any part of the liquid container or the liquid storage device, such as using extrusion molding, injection molding or other molding processes known to a person skilled in the art. Furthermore, the liquid container or the liquid storage device of this invention may be made of various materials, such different plastic materials, or materials commonly used for medical grade products.
The above detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the term "exemplary" means "serving as an example, instance, or illustration." Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. | 1. A liquid container (1) for gas humidification, comprising: a first storage chamber (10) comprising a bottom (11); and a second storage chamber (20) comprising a top wall (21), a bottom wall (22) and a side wall (23) connected between the top wall (21) and the bottom wall (22), the second storage chamber (20) being provided with at least one opening (24, 24a, 24b) which is above the bottom (11) of the first storage chamber (10), thereby enabling liquid in the second storage chamber (20) to flow into the first storage chamber (10) in a unidirectional way. | 2. The liquid container (1) for gas humidification of claim 1, wherein the opening (24, 24a, 24b) is formed on the bottom wall (22).
3. The liquid container (1) for gas humidification of claim 1, wherein a pipe (25, 26) is farmed extending outwardly from the opening (24, 24a, 24b).
4. The liquid container (1) for gas humidification of claim 1. wherein the opening (24, 24a, 24b) is a gas flow opening (24, 24a, 24b), and the bottom wall (22) is further provided with a liquid flow opening (24, 24a, 24b).
5. The liquid container (1) for gas humidification of claim 4, wherein the gas flow opening (24, 24a, 24b) is penetrated by a gas flow pipe (25).
6. The liquid container (1) for gas humidification of claim 4, wherein a liquid flow pipe (26) is formed extending outwardly from the liquid flow opening (24, 24a, 24b), and a terminal orifice (26a) of the liquid flow pipe (26) is above the bottom (11) of the first storage chamber (10).
7. The liquid container (1) for gas humidification of claim 1, wherein the side (23) wall is airtightly connected with the top wall (21) and the bottom wall (22).
8. The liquid container (1) for gas humidification of claim 1, further comprising a cover (30) connected with the first storage chamber (10) and having a gas outlet (31).
9. The liquid container (1) for gas humidification of claim 8, wherein the second storage chamber (20) is connected with the cover (30) and received between the cover (30) and the first storage chamber (10).
10. The liquid container (1) for gas humidification of claim 1, wherein the bottom (11) of the first storage chamber (10) at least partially defines at heating zone (12). |
2837399 | Liquid container for gas humidification and liquid storage device | 2 | Based on the following detailed description of an invention, generate the patent claims. There should be 4 claims in total. The first, independent claim is given and the remaining 3 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | Embodiments are illustrated in the accompanying figures to improve understanding of concepts as presented herein. Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to others to facilitate understanding of the embodiments.
Since various aspects and embodiments are merely exemplary and not limiting, after reading this specification, skilled artisans appreciate that other aspects and embodiments are possible without departing from the scope of the invention. Other features and benefits of any one or more of the embodiments will be apparent from the following detailed description and the claims.
The use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. Accordingly, this description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
As used herein, the terms "comprises," "comprising," "includes," "'including," "has," "having" or any other variation thereof are intended to cover a non-exclusive inclusion. For example, a component, structure, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such component, structure, article, or apparatus. Further, unless expressly stated to the contrary, the term "or" refers to an inclusive or and not to an exclusive or. For example, a condition "A or B" is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
As illustrated in Figure 1, an exemplary embodiment according to the present disclosure provides a liquid container 1 for humidifying gas and increasing gas humidity, wherein the gas may include air, pure gas or gas mixture, and the humidification may be, without limitation, carried out by heating, evaporation or ultrasonic atomization. The liquid container 1 mainly comprises two chambers, which are the first storage chamber 10 and the second storage chamber 20 disposed for example in the first storage chamber 10. Optionally, as shown in Figure 1, the liquid container 1 may also include a cover 30 covering the first storage chamber 10 and the second storage chamber 20.
The first storage chamber 10 has a reservoir primarily for holding liquid to be humidified, such as water, normal saline or the like. If humidification is carried out by heating, the liquid to be humidified may be heated and evaporated by a heating board, a heater, a heating plate, or the like installed at a certain position (e.g. heating zone 12) of the bottom 11 of the first storage chamber 10.
The second storage chamber 20 also includes a reservoir primarily for holding supplemental liquid such as water, normal saline or the like. The liquid within the second storage chamber 20 and the first storage chamber 10 may be the same or different. An opening 24 is formed on the second storage chamber 20 such as at the bottom, such that gas is allowed to enter the second storage chamber 20 via the opening 24 and cause air pressure change in the second storage chamber 20, and such that liquid in the second storage chamber 20 may flow downwardly via the opening 24 into the first storage chamber 10 so as to supplement the liquid amount in the first storage chamber 10. In addition, the second storage chamber 20 may be optionally equipped on its surface with an aerodynamic structure 28, such as fins of a certain shape, to regulate the time of gas staying in the liquid container 1 and its movement distance, or to define a path tor gas flow, for example.
Moreover, in this embodiment, the liquid container 1 also includes an optional cover 30. The cover 30 may be connected with the first storage chamber 10 to situate the second storage chamber 20 therebetween. In this case, gas entering the gas humidification space of the liquid container 1 via the gas inlet 32 may move along the gas flow path defined by the aerodynamic structure 28 and, after absorbing a certain amount of moisture, leave the gas humidification space of the liquid container 1 via the gas outlet 31, to a user's respiratory tract through a duct for example connected with the gas outlet 31.
As used herein, the term "connect," "connected," "connected to" or "connected with" means "combined, joined, linked or assembled together," and includes direct connection where no intermediate (e.g. a gasket or washer) exists and indirect connection where an intermediate exists between two elements to be connected. In addition, when different components are connected, these components may form an integral, one-piece structure such as by integration in which different components act as different parts of the integral structure, or these components may be distinct and separate components connected together. Unless otherwise specified, means for Joining distinct and separate components together includes interlocking, engagement, fastening, mortise and tenon joint, or any other connection means known and understood in the mechanical arts.
Accordingly, depending on the preferences in use and during manufacture, the first storage chamber 10 and the second storage chamber 20 can form an integral structure, or they can be separate and distinct structures assembled together. Similarly, the second storage chamber 20 and the cover 30 can form an integral structure, or they can be separate and distinct structures assembled together.
Figure 2 illustrates a cross-sectional view of a liquid storage device according to one embodiment of this invention. The liquid storage device 2 mainly comprises a first storage chamber 10, a second storage chamber 20 and a cover 30. As an outer chamber, the first storage chamber 10 defines a receiving space 13 therein, and as an inner chamber, the second storage chamber 20 is disposed within the receiving space 13, wherein the inner chamber defines inwardly a supplemental liquid storage space 27. In this embodiment, the second storage chamber 20 primarily consists of a top wall 21, a bottom wall 22 and a side wall 23 connected therebetween, preferably in an airtight manner. For example, the bottom wall 22 and side wall 23 of the second storage chamber 20 may form a unitary and integral structure, and the top wall 21 of the second storage chamber 20 may be removably covered on the side wall 23, such that the space defined collectively by the top wall 21, the bottom wall 22 and the side wall 23 is airtight with respect to and not in gas communication with the exterior except through the opening 24, as described below.
To form gas communication and liquid communication between the first storage chamber 10 and the second storage chamber 20, the second storage chamber 20 is provided with at least one opening 24 for example on the bottom wall 22, such that gas can enter the second storage chamber 20 and liquid can leave the supplemental liquid storage space 27 of the second storage chamber 20. As illustrated in Figure 2, the position of the opening 24 is above the bottom 11 of the first storage chamber 10, so liquid from the second storage chamber 20 will be driven naturally to flow downwardly into the first storage chamber 10.
In this exemplary embodiment, thee is only one opening 24 termed on the bottom wall 22 of the second storage chamber 20, so gas and liquid respectively enter and leave the space defined within the second storage chamber 20 via the same opening 24. In order to serve the dual purpose of gas entry and liquid exit, parameters of the opening 24 such as aperture size, shape and the so on can be designed without undue experimentation, such as in view of the cohesion force within liquid in the second storage chamber 20, hydraulic pressure, air pressure and the like. A circular opening may be used, for example, which has an aperture diameter ranging from 0.5 mm to 5 mm, but not limited thereto.
In order to further explain the concepts and principles behind this invention, the operational states of various embodiments with the presence of liquid are described with the accompanying drawings. However, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Figure 3 illustrates a cross-sectional view of an exemplary liquid storage device for gas humidification in an operational state. When in use, the second storage chamber 20 of the liquid storage device 2 can first be filled with liquid. The filling process may involve separating the top wall of the second storage chamber 20 from the side wall, filling the liquid into the supplemental liquid storage space 27, and then joining or connecting the top wall and the side wall in an airtight manner. Alternatively, a switchable liquid injection port may be formed on any desirable portion of the second storage chamber 20 for liquid injection, and after being filled with the liquid, the second storage chamber 20 may then be assembled between the cover 30 and the first storage chamber 10. Further alternatively, the second storage chamber 20 may be made as a disposable component, and the supplemental liquid storage space 27 is filled with the liquid In advance during production and then sealed airtight, such that the second storage chamber 20 can be mounted by uses without the additional liquid loading process. For example, the second storage chamber 20 may be placed into the receiving space of the first storage chamber 10, allowing liquid to flow into the first storage chamber 10 through the opening on the second storage chamber 20. Depending on the user's need, a predetermined amount of liquid may be loaded into the first storage chamber 10 before setting the second storage chamber 20.
In this embodiment, two openings 24a and 24b are formed on the bottom of the second storage chamber 20. A liquid flow pipe 26 is formed extending from the openings 24a downwardly, and the terminal orifice 26a of the liquid flow pipe 26 is above the bottom 11 of the first storage chamber 10. In addition, a gas flow pipe 25 is formed extending from the openings 24b downwardly. Two openings are used in this embodiment for allowing liquid to move from the second storage chamber 20 into the first storage chamber 10 and allowing gas to move from the first storage chamber 10 into the second storage chamber 20. However, the liquid or gas is not limited to entering or exiting trough a specific opening. In word words, when two or more openings are formed, each opening may serve for gas and/or liquid passage. In view of several factors including aperture size, opening shape, cohesion force within liquid, hydraulic pressure, air pressure and the like, different openings may be designed either with more tendency toward allowing gas to enter the second storage chamber 20 or with more tendency toward allowing liquid to leave the second storage chamber 20, and the size or shape of different openings may be the same or different. In this embodiment, for example, the openings 24a and 24b may individually have an aperture diameter from 0.5 mm to 5 mm, but not limited thereto.
As shown in Figure 3, the two openings are both extended downwardly to form the gas flow pipe 25 and the liquid flow pipe 26 respectively, and the length, the pipe diameter, and other parameters of the two pipes may be the same or different. For example, the length of the liquid flow pipe 26 may be greater than that of the gas flow pipe 25. In a situation where a plurality of pipes of differellt lengths are formed, the longer pipe sustains a greater pressure at the bottom end, so liquid has a greater tendency to flow from the longer pipe. In other words, a longer pipe, such as the liquid flow pipe 26 in this embodiment, is more suitable tor discharging liquid from the second storage chamber 20. However, as stated above, the liquid flow pipe 26 is not limited to serve as a passage for liquid discharge only but may also be useful for gas entry in some circumstances, and, similarly, the gas flow pipe 25 is not limited to serve as a passage for gas entry only but may also be useful for liquid discharge in some circumstances, both depending on various environmental parameters in operational states and the structural design of the second storage chamber 20. In this embodiment, for example, the length of the gas flow pipe 25 extending downwardly may be less than 10 mm, and the liquid flow pipe 26 may be 5 mm longer than the gas flow pipe 25, such as less man 15 mm, but not limited thereto.
In an operational state, gas primarily enters the second storage chamber 20 through the gas flow pipe 25, and liquid primarily enters the first storage chamber 10 from the supplemental liquid storage space 27 through the liquid flow pipe 26, such that the liquid level in the first storage chamber 10 gradually raises and that the liquid level in the supplemental liquid storage space 27 gradually lowers at the same time. When the liquid level in the first storage chamber 10 raises to the position of the orifice at the bottom of the gas flow pipe 25, before which the terminal orifice 26a of the liquid flow pipe 26 has been submerged by the liquid, the gas flow pipe 25 is sealed by the liquid, and gas is prevented from entering the second storage chamber 20 via the gas flow pipe 25 and causing pressure change, thus achieving a substantially balanced or steady state of the system within the liquid storage device 2. Accordingly, in an embodiment where a plurality of openings are employed, the position or height of the opening(s) primarily for gas entry can determine the liquid level in the thirst storage chamber 10 under the steady state, during which the space within the first storage chamber 10 is divided into two parks - the space below the opening terming a storage space for liquid to be heated (i.e. the space occupied by the liquid, as indicated by the numeral 14 in Figure 3 ), and the space above the opening forming a gas humidification space (i.e. the space occupied by the gas, as indicated by the numeral 15 in Figure 3 ).
During operation of a humidifier such as a heater or an atomiser, as shown in Figure 4, liquid in the storage space for liquid to be heated 14 will be evaporated or atomized and then be absorbed by the gas in the gas humidification space 15, which then leaves the liquid, storage device 2 from the gas outlet 31. Thus, during operation, the liquid level in the first storage chamber 10 will gradually lower, and when the gas flow pipe 25 is no longer sealed by the liquid, gas may re-enter the second storage chamber 20 via the gas flow pipe 25 and cause air pressure change in the second storage chamber 20 (i.e. air pressure increases due to the increasing gas amount), such that liquid may be driven to flow downwardly and leave the supplemental liquid storage space 27 via the liquid flow pipe 26, achieving the purpose of automatic supplement of liquid to the storage space tor liquid to be heated 14. Subsequently, the liquid level gradually raises again in the storage space for liquid to be heated 14, and the gas flow pipe 25 is sealed by the raising liquid level to block the gas entry into the second storage chamber 20 therefrom, thereby reaching the steady state mentioned above as illustrated in Figure 3. Therefore, when in use, the design of this embodiment can maintain a substantially constant amount of liquid in the first storage chamber 10.
While various stages during operation are described according to their temporal sequence, however, it is understood that, when in actual use, different stages may happen one after the other or almost at the same time. Therefore, during operation, the liquid storage device 2 is substantially maintained at a dynamic equilibrium or steady state until all the liquid in the supplemental Liquid storage space 27 is used up.
Figure 5 illustrates a cross-sectional view of a liquid storage device 2 according to another embodiment of this invention, in which the opening primarily for gas passage is penetrated by the gas flow pipe 25. The operational principle behind this embodiment is substantially the same as other embodiments. When the bottom opening of the gas flow pipe 25 is not sealed for example by liquid, gas enters the second storage chamber 20 via the gas flow pipe 25, and liquid in the supplemental liquid storage space 27 flows into the first storage chamber 10 through the liquid flow pipe 26. When the liquid level in the first storage chamber 10 raises to a predetermined degree, such as sealing the bottom opening of the gas flow pipe 25, gas is prevented from entering the second storage chamber 20 and inducing air pressure increase therein, and liquid flow is inhibited from the supplemental liquid storage space 27 into the first storage chamber 10. In addition, when the liquid level in the first storage chamber 10 lowers during gas humidification, gas can be allowed to enter the second storage chamber 20 via the gas flow pipe 25 again, and liquid is similarly allowed to flow from the supplemental liquid storage space 27 into the first storage chamber 10 again.
The present embodiment is characterized in that the gas flow pipe 25 penetrates into the second storage chamber 20 and that the top opening thereof is above the liquid level in the second storage chamber 20, such that the gas flow pipe 25 contains substantially no liquid therein. Thus, when entering the second storage chamber 20 via the gas flow pipe 25, gas will not contact with liquid and will not form bubbles as shown in Figure 4, thereby reducing the voice or noise from the operating liquid storage device 2 caused by bursting bubbles, and making this embodiment particularly suitable for a situation which requires less noise, such as when a user is sleeping.
As mentioned above, in this invention, different components or structures may be formed as one piece or individually and separately formed and then assembled together. For example, suitable molds may be used to make any part of the liquid container or the liquid storage device, such as using extrusion molding, injection molding or other molding processes known to a person skilled in the art. Furthermore, the liquid container or the liquid storage device of this invention may be made of various materials, such different plastic materials, or materials commonly used for medical grade products.
The above detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the term "exemplary" means "serving as an example, instance, or illustration." Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. | 11. A liquid storage device (2), comprising: an outer chamber (10) defining a receiving space (13) therein; and an inner chamber (20) received in the receiving space (13), the inner chamber (20) defining a supplemental liquid storage space (27) therein and being provided with at least one opening (24, 24a, 24b), wherein a portion of the receiving space (13) not occupied by the inner chamber (20) is divided in respect to the opening (24, 24a, 24b) into a storage space for liquid to be heated (14), which is below the opening (24, 24a, 24b), and a gas humidification space (15), which is above the opening (24, 24a, 24b). | 12. The liquid storage device (2) of claim 11, wherein the opening (24, 24a, 24b) is a gas flow opening (24, 24a, 24b), and the inner chamber (20) is further provided with a liquid flow opening (24, 24a, 24b).
13. The liquid storage device (2) of claim 12, wherein the gas flow opening (24, 24a, 24b) and the liquid flow opening (24, 24a, 24b) are individually surrounded by a pipe (25, 26).
14. The liquid storage device (2) of claim 11, further comprising: a cover (30) connected with the outer chamber (10); a gas inlet (32) allowing introduction of gas into the gas humidification space (15); and a gas outlet (31) through which the gas can escape from the gas humidification space (15) after being humidified. |
2866311 | Method and device for controlling a carrier-envelope phase and/or an intensity of output pulses of a pulse laser device | 1 | Based on the following detailed description of an invention, generate the patent claims. There should be 8 claims in total. The first, independent claim is given and the remaining 7 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | Preferred embodiments of the invention are described in the following with particular reference to the configuration of the pump laser diodes and the control thereof. Further features of the pulse laser device, like the design of the resonator cavity or features of the control loops, are not described in detail if they are known as such from prior art (see e. g. resonator cavity in [3], and control loops in [10], [11]). According to the illustrated embodiments, the invention can be implemented with multiple configurations, including e. g. one or two modulated laser diodes and/or one or more stable laser diode.
Figures 1, 2 and 3 illustrate basic embodiments of the invention, wherein one single modulated laser diode or multiple, e. g. two modulated laser diodes are provided in combination with one stable laser diode or multiple, e. g. three stable laser diodes, resp.. Figures 4 to 8 illustrate preferred modifications of these embodiments, wherein the modulated laser diodes are controlled using first and/or second control loops, resp..
According to Figure 1, the pulse laser device 100 comprises a thin disk module including a thin disk laser medium 10, like an Yb-YAG disk crystal with a thickness of 220 µm and a diameter of 10 mm. The Yb-YAG disk crystal has pronounced absorption maxima at 940 nm and at 969 nm and a further absorption band at 915 nm. The thin disk module is arranged in a resonator cavity (not shown). The thin disk laser medium 10 is pumped with cw pump laser diodes, which comprise one single modulated laser diode 21 and one single stable laser diode 23, each being electrically connected with an associated current source. The modulated laser diode 21 (e. g. type: M1F2S22-968,5.[0,6]-12C-SS2.1-VBG, manufacturer: DILAS GmbH) has a cw pump light output at 969 nm. It is connected with a low power current source 31 with modulation capability (current source type e. g. LDX-32420, manufacturer: Newport), which can provide maximal electrical power of 80 W. The stable laser diode 23 (e. g. type: 500 W, coupled into the fiber with NA = 0.22 and 1 mm diameter, manufacturer: Laserline GmbH) with a cw pump light output at 940 nm is driven with a stabilized high power current source 33 (current source type e. g. LDX-36040-30, manufacturer: Newport), which can provide a maximal electrical power of 1200 W. According to the invention, the used in the practical application output power of the modulated laser diode 21 (mean output power e. g. 8 W) is smaller than the whole output power of the stabilized laser diode 23 (output power e. g. 220 W).
The outputs of both laser diodes are fiber-coupled with output fibers 21.1 and 23.1 to collimating optics 21.2 and 23.2, resp.. The collimating optics 21.2 and 23.2 relay collimated pump light to the beam combiner 41 where the laser diode outputs are combined. The beam combiner 41 comprises a wavelength dependent combiner including at least one dichroic mirror. The combined pump light is directed to the laser medium 10 in the resonator cavity (not shown), where laser output pulses are created e. g. with the following parameters: power: 40 W, pulse duration 250 fs, repetition rate: 38 MHz and centre wavelength: about 1030 nm.
Figure 2 shows an alternative embodiment of the pulse laser device 100, wherein the thin-disk laser medium 10, like the Yb-YAG disk crystal, is pumped with one single modulated laser diode 21 and multiple, e. g. three stable laser diodes 23, 24 and 25. The modulated laser diode 21 is operated as described with reference to Figure 1. The stable laser diodes 23, 24 and 25 are connected with one common stabilized high power current source 33. All laser diode outputs are fiber-coupled with output fibers 21.1, 23.1, 24.1 and 25.1 to a fiber beam combiner 42 where the laser diode outputs of the modulated laser diode 21 and the stable laser diodes 23, 24 and 25 are combined and subsequently directed to the laser medium 10 in the resonator cavity (not shown). The fiber beam combiner 42 comprises a monolithic all-fiber beam combiner (known from the prior art), which superimposes the outputs from the pump laser diodes by a direct connection of the output fibers 21.1, 23.1, 24.1 and 25.1, resp..
According to Figure 3, the pulse laser device 100 is configured similar to the above embodiments of Figures 1 and 2. Deviating from Figure 1, the laser medium 10, like the Yb-YAG disk crystal, is pumped with two modulated laser diodes 21, 22 and one stable laser diode 23. The modulated laser diodes 21, 22 provide the output pump light at different wavelengths, which are selected in dependency on the absorption maxima of the Yb-YAG disk crystal, e.g. at 915 nm and 969 nm. The modulated laser diodes 21, 22 and the stable laser diode 23 are connected with separate low power current sources 31, 32 with modulation capability and a stabilized high power current source 33, resp.. All laser diode outputs are fiber-coupled with output fibers 21.1, 22.1 and 23.1 to collimating optics 21.2, 22.2 and 23.2, resp.. The collimating optics 21.2 and 22.2 relay collimated pump light to a first beam combiner 41 where the laser diode outputs of the modulated laser diodes 21, 22 are combined in a first step. Again, the first beam combiner 41 comprises a wavelength dependent combiner including at least one dichroic mirror. The combined beam is combined with the laser diode output of the stable laser diode 23 at a second beam combiner 43 and subsequently directed to the laser medium 10 in the resonator cavity (not shown).
For controlling an intensity noise and/or a carrier-envelope phase of laser output pulses of the pulse laser device 100, the output power of the modulated laser diode 21 (or: diodes 21 and 22) is modulated by controlling the drive current thereof, while the stable laser diode 23 has a constant output power. Depending on the application, the modulation of the modulated laser diode 21, 22 can follow a predetermined time scheme, or it is stabilized using at least one control loop as shown in Figures 4 to 8.
The embodiments of Figures 4 to 8 are configured with one or multiple modulated laser diodes 21, 22 like the embodiments of Figures 1 and 2, resp.. Collimating optics 44 are used for directing the combined pump light to the laser medium 10 ( Figures 4 to 6 ). Furthermore, deviating from the remaining illustrations, Figures 4 to 6 show the pump laser diodes 21, 22 and 23 without separate current sources. With these embodiments, the current sources and diodes are provided as integrated units.
The pulse laser device 100 of Figure 4 comprises one modulated laser diode 21 and one stable laser diode 23, both being operated at different wavelengths and being fibre coupled and combined with the beam combiner 41. The combined output is relayed via the collimating optics 44 to the thin-disk laser medium 10. According to Figure 4, the pulse laser device 100 further includes a first control loop 50 (CEP loop) for a CEP feedback control of the modulated laser diode 21. The first control loop 50 includes a spectral broadening and compression unit 51, an F _CEO detection unit 52, an RF reference unit 53 and phase locking electronics 54.
The spectral broadening and compression unit 51 comprises a 35 µm mode field diameter photonic crystal fiber (PCF, LMA35) and a combination of chirped compression mirrors. Output pulses of the pulse laser 100 are coupled as an input to the PCF. It is possible to couple the whole power available from the resonator cavity, or a part thereof, e. g. with a coupling efficiency of 85 %. The chirped compression mirrors with GDD = - 500 fs ^2 and without compensation of higher-order dispersion are arranged for e. g. 8 reflections, leading to a pulse duration below 30 fs.
The spectrally broadened and compressed pulses are sent to the F _CEO detection unit 52, which is arranged the carrier envelope offset (CEO) frequency of the pulse, which is a direct measure for the CEP of the output pulses of the pulse laser device 100. The F _CEO detection unit 52 comprises an f-to-2f-interferometer, e. g. as described in [6]. The octave spanning spectrum is generated with a PCF (SC-3.7-975, manufacturer: NKT photonics) with 3.7 µm core diameter by launching about 300 mW and 30 fs pulses. With alternative embodiments of the invention, a 2f-to-3f-interferometer or a monolithic DFG setup, as described in [7], can be used instead of the f-to-2f-interferometer.
The RF reference unit 53 comprises a stabilized radiofrequency source (e. g. 10.5 MHz). The phase locking electronics 54 include a phase detector detecting a frequency difference between the reference signal from the RF reference unit 53 and the output of the F _CEO detection unit 52 and controlling the drive current of the modulated laser diode 21. In practical tests, the CEO frequency was tuned to stay close to 10.5 MHz, and then this signal was band pass filtered, amplified and sent to a first phase detector input of the phase locking electronics 54. The reference signal from the RF reference unit 53 was fed to the second phase detector input of the phase locking electronics 54. CEO frequency sensitivity due to the variation of the drive current was found to be about 4 MHz/W at 200 W pump power.
Figure 9 shows an experimental result obtained with the embodiment of Figure 4. The CEP error measured with the first control loop 50 including the f-to-2f-interferometer and a 4 bit digital phase detector shows a tight locking of the CEP and demonstrates the phase noise around 250 mrad measured in the 1 Hz to 1 MHz bandwidth.
The pulse laser device 100 of Figure 5 comprises one modulated laser diode 21 and one stable laser diode 23, the beam combiner 42, the collimating optics 44 and the thin-disk laser medium 10 as shown in Figure 4. Furthermore, according to Figure 5, the pulse laser device 100 includes a second control loop 60 (intensity noise loop) for an intensity feedback control of the modulated laser diode 21. The second control loop 60 includes an oscillator noise detection unit 61, a voltage reference source 63 and a PID controller 62, which is arranged for controlling the drive current of the modulated laser diode 21. The oscillator noise detection unit 61 detects intensity fluctuations of the output pulses of the pulse laser device 100 relative to a reference voltage provided by the voltage reference source 63. The error signal from the PID controller 62 is fed to the current source of the modulated laser diode 21. Advantageously, the second control loop 60 allows a reduction of intensity noise fluctuations, which could be introduced by a residual noise of the stabilized laser diode or oscillator itself.
According to Figure 6, the pulse laser device 100 includes both the first control loop 50 and additionally the second control loop 60 for oscillator intensity noise compensation. As described with reference to Figure 3, the pulse laser device 100 includes first and second modulated laser diodes 21, 22 and a stable laser diode 23. The pump laser diodes 21, 22 and 23 emit at different wavelengths λ _1, λ _2 and λ _3, which are selected in dependency on the absorption maxima of the laser medium 10. The output of the pump laser diodes 21, 22 and 23 is combined with two steps using the fiber beam combiners 41, 42. The combined output is directed with collimating optics 44 to the laser medium 10. The first control loop 50 is configured with the components 51 to 54 and controls the first modulated laser diode 21 as described with reference to Figure 3. The second control loop 60 is configured with the components 61 to 63 and controls the second modulated laser diode 22 as described with reference to Figure 4.
Figures 7 and 8 show further embodiments of the invention, wherein the first control loop 50 or the second control loop is provided with the embodiment of the pulse laser device 100 as shown in Figure 2. Again, the beam combiners 42 in Figures 7 and 8 comprise monolithic all-fiber beam combiners, which superimpose the output from the pump laser diodes by a direct connection of the output fibers. As a further alternative, both of the first and second control loops 50, 60 can be provided with the fibre coupled embodiment of Figure 2, preferably if two separate modulated laser diodes are provided. | 1. Method of controlling output pulses of a pulse laser device (100) including a thin-disk laser medium (10), in particular controlling a carrier-envelope phase and/or an intensity of the output pulses, including the steps of - pumping the thin-disk laser medium (10) of the pulse laser device (100) with multiple pump laser diodes (21, 22, 23), which include at least one modulated laser diode (21, 22) which is powered by a current source (31, 32) with modulation capability, and - controlling the output pulses by modulating the output power of the at least one modulated laser diode (21, 22), which is modulated by controlling a drive current thereof,: characterized in that - the pump laser diodes further include at least one stable laser diode (23), which has a constant output power, and - the output power of the at least one modulated laser diode (21, 22) is smaller than the whole output power of the at least one stable laser diode (23). | 2. Method according to claim 1, wherein the output of the at least one stable laser diode (23) and the output of the at least one modulated laser diode (21, 22) are combined by - a beam combiner (41, 43) which is configured for a free space beam combination, or - a fiber beam combiner (42).
3. Method according to one of the foregoing claims, including at least one of the features - a modulation depth of the output power of the at least one modulated laser diode (21, 22) is at least 2 % a pump power absorbed by the thin-disk laser medium (10), - a modulation depth of the output power of the at least one modulated laser diode (21, 22) is at most 20 % of a pump power absorbed by the thin-disk laser medium (10), - an oscillator intensity noise of the output pulses is controlled by modulating the output power of the at least one modulated laser diode (21, 22), - the carrier-envelope phase of the output pulses is controlled by modulating the output power of the at least one modulated laser diode (21, 22), - the at least one stable laser diode (23) and the at least one modulated laser diode (21, 22) are operated at different output wavelengths selected in accordance to absorption maxima of the thin-disk laser medium (10), - the at least one stable laser diode (23) and the at least one modulated laser diode (21, 22) are operated at different polarizations, and - the at least one stable laser diode and the at least one modulated laser diode are fiber coupled and combined with a fiber beam combiner (42).
4. Method according to one of the foregoing claims, including at least one of the features - the at least one modulated laser diode (21, 22) is modulated by an analogue control of the drive current thereof, and - the at least one modulated laser diode (21, 22) is modulated with a broadband control.
5. Method according to one of the foregoing claims, wherein - the carrier-envelope phase of the output pulses is controlled using a first control loop (50), wherein the drive current of the at least one modulated laser diode (21, 22) is controlled in dependency on a detected carrier-envelope offset frequency of the output pulses and a radiofrequency reference signal.
6. Method according to one of the foregoing claims, wherein - the intensity noise of the output pulses is controlled using a second control loop (60), wherein the drive current of the of the at least one modulated laser diode (21, 22) is controlled in dependency on a detected oscillator noise.
7. Method according to claims 5 and 6, wherein - the pump laser diodes include at least two modulated laser diodes (21, 22), - the first control loop (50) is used for controlling a first one (21) of the two modulated laser diodes (21, 22), and - the second control loop (60) is used for controlling a second one (22) of the at least two modulated laser diodes (21, 22).
8. Method according to claim 7, including at least one of the features - the modulated laser diodes (21, 22) are operated at different output wavelengths selected in accordance to absorption maxima of the thin-disk laser medium (10), - the modulated laser diodes (21, 22) are operated at different polarizations, and - the modulated laser diodes are fiber coupled diodes combined with a fiber beam combiner. |
2866311 | Method and device for controlling a carrier-envelope phase and/or an intensity of output pulses of a pulse laser device | 2 | Based on the following detailed description of an invention, generate the patent claims. There should be 7 claims in total. The first, independent claim is given and the remaining 6 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | Preferred embodiments of the invention are described in the following with particular reference to the configuration of the pump laser diodes and the control thereof. Further features of the pulse laser device, like the design of the resonator cavity or features of the control loops, are not described in detail if they are known as such from prior art (see e. g. resonator cavity in [3], and control loops in [10], [11]). According to the illustrated embodiments, the invention can be implemented with multiple configurations, including e. g. one or two modulated laser diodes and/or one or more stable laser diode.
Figures 1, 2 and 3 illustrate basic embodiments of the invention, wherein one single modulated laser diode or multiple, e. g. two modulated laser diodes are provided in combination with one stable laser diode or multiple, e. g. three stable laser diodes, resp.. Figures 4 to 8 illustrate preferred modifications of these embodiments, wherein the modulated laser diodes are controlled using first and/or second control loops, resp..
According to Figure 1, the pulse laser device 100 comprises a thin disk module including a thin disk laser medium 10, like an Yb-YAG disk crystal with a thickness of 220 µm and a diameter of 10 mm. The Yb-YAG disk crystal has pronounced absorption maxima at 940 nm and at 969 nm and a further absorption band at 915 nm. The thin disk module is arranged in a resonator cavity (not shown). The thin disk laser medium 10 is pumped with cw pump laser diodes, which comprise one single modulated laser diode 21 and one single stable laser diode 23, each being electrically connected with an associated current source. The modulated laser diode 21 (e. g. type: M1F2S22-968,5.[0,6]-12C-SS2.1-VBG, manufacturer: DILAS GmbH) has a cw pump light output at 969 nm. It is connected with a low power current source 31 with modulation capability (current source type e. g. LDX-32420, manufacturer: Newport), which can provide maximal electrical power of 80 W. The stable laser diode 23 (e. g. type: 500 W, coupled into the fiber with NA = 0.22 and 1 mm diameter, manufacturer: Laserline GmbH) with a cw pump light output at 940 nm is driven with a stabilized high power current source 33 (current source type e. g. LDX-36040-30, manufacturer: Newport), which can provide a maximal electrical power of 1200 W. According to the invention, the used in the practical application output power of the modulated laser diode 21 (mean output power e. g. 8 W) is smaller than the whole output power of the stabilized laser diode 23 (output power e. g. 220 W).
The outputs of both laser diodes are fiber-coupled with output fibers 21.1 and 23.1 to collimating optics 21.2 and 23.2, resp.. The collimating optics 21.2 and 23.2 relay collimated pump light to the beam combiner 41 where the laser diode outputs are combined. The beam combiner 41 comprises a wavelength dependent combiner including at least one dichroic mirror. The combined pump light is directed to the laser medium 10 in the resonator cavity (not shown), where laser output pulses are created e. g. with the following parameters: power: 40 W, pulse duration 250 fs, repetition rate: 38 MHz and centre wavelength: about 1030 nm.
Figure 2 shows an alternative embodiment of the pulse laser device 100, wherein the thin-disk laser medium 10, like the Yb-YAG disk crystal, is pumped with one single modulated laser diode 21 and multiple, e. g. three stable laser diodes 23, 24 and 25. The modulated laser diode 21 is operated as described with reference to Figure 1. The stable laser diodes 23, 24 and 25 are connected with one common stabilized high power current source 33. All laser diode outputs are fiber-coupled with output fibers 21.1, 23.1, 24.1 and 25.1 to a fiber beam combiner 42 where the laser diode outputs of the modulated laser diode 21 and the stable laser diodes 23, 24 and 25 are combined and subsequently directed to the laser medium 10 in the resonator cavity (not shown). The fiber beam combiner 42 comprises a monolithic all-fiber beam combiner (known from the prior art), which superimposes the outputs from the pump laser diodes by a direct connection of the output fibers 21.1, 23.1, 24.1 and 25.1, resp..
According to Figure 3, the pulse laser device 100 is configured similar to the above embodiments of Figures 1 and 2. Deviating from Figure 1, the laser medium 10, like the Yb-YAG disk crystal, is pumped with two modulated laser diodes 21, 22 and one stable laser diode 23. The modulated laser diodes 21, 22 provide the output pump light at different wavelengths, which are selected in dependency on the absorption maxima of the Yb-YAG disk crystal, e.g. at 915 nm and 969 nm. The modulated laser diodes 21, 22 and the stable laser diode 23 are connected with separate low power current sources 31, 32 with modulation capability and a stabilized high power current source 33, resp.. All laser diode outputs are fiber-coupled with output fibers 21.1, 22.1 and 23.1 to collimating optics 21.2, 22.2 and 23.2, resp.. The collimating optics 21.2 and 22.2 relay collimated pump light to a first beam combiner 41 where the laser diode outputs of the modulated laser diodes 21, 22 are combined in a first step. Again, the first beam combiner 41 comprises a wavelength dependent combiner including at least one dichroic mirror. The combined beam is combined with the laser diode output of the stable laser diode 23 at a second beam combiner 43 and subsequently directed to the laser medium 10 in the resonator cavity (not shown).
For controlling an intensity noise and/or a carrier-envelope phase of laser output pulses of the pulse laser device 100, the output power of the modulated laser diode 21 (or: diodes 21 and 22) is modulated by controlling the drive current thereof, while the stable laser diode 23 has a constant output power. Depending on the application, the modulation of the modulated laser diode 21, 22 can follow a predetermined time scheme, or it is stabilized using at least one control loop as shown in Figures 4 to 8.
The embodiments of Figures 4 to 8 are configured with one or multiple modulated laser diodes 21, 22 like the embodiments of Figures 1 and 2, resp.. Collimating optics 44 are used for directing the combined pump light to the laser medium 10 ( Figures 4 to 6 ). Furthermore, deviating from the remaining illustrations, Figures 4 to 6 show the pump laser diodes 21, 22 and 23 without separate current sources. With these embodiments, the current sources and diodes are provided as integrated units.
The pulse laser device 100 of Figure 4 comprises one modulated laser diode 21 and one stable laser diode 23, both being operated at different wavelengths and being fibre coupled and combined with the beam combiner 41. The combined output is relayed via the collimating optics 44 to the thin-disk laser medium 10. According to Figure 4, the pulse laser device 100 further includes a first control loop 50 (CEP loop) for a CEP feedback control of the modulated laser diode 21. The first control loop 50 includes a spectral broadening and compression unit 51, an F _CEO detection unit 52, an RF reference unit 53 and phase locking electronics 54.
The spectral broadening and compression unit 51 comprises a 35 µm mode field diameter photonic crystal fiber (PCF, LMA35) and a combination of chirped compression mirrors. Output pulses of the pulse laser 100 are coupled as an input to the PCF. It is possible to couple the whole power available from the resonator cavity, or a part thereof, e. g. with a coupling efficiency of 85 %. The chirped compression mirrors with GDD = - 500 fs ^2 and without compensation of higher-order dispersion are arranged for e. g. 8 reflections, leading to a pulse duration below 30 fs.
The spectrally broadened and compressed pulses are sent to the F _CEO detection unit 52, which is arranged the carrier envelope offset (CEO) frequency of the pulse, which is a direct measure for the CEP of the output pulses of the pulse laser device 100. The F _CEO detection unit 52 comprises an f-to-2f-interferometer, e. g. as described in [6]. The octave spanning spectrum is generated with a PCF (SC-3.7-975, manufacturer: NKT photonics) with 3.7 µm core diameter by launching about 300 mW and 30 fs pulses. With alternative embodiments of the invention, a 2f-to-3f-interferometer or a monolithic DFG setup, as described in [7], can be used instead of the f-to-2f-interferometer.
The RF reference unit 53 comprises a stabilized radiofrequency source (e. g. 10.5 MHz). The phase locking electronics 54 include a phase detector detecting a frequency difference between the reference signal from the RF reference unit 53 and the output of the F _CEO detection unit 52 and controlling the drive current of the modulated laser diode 21. In practical tests, the CEO frequency was tuned to stay close to 10.5 MHz, and then this signal was band pass filtered, amplified and sent to a first phase detector input of the phase locking electronics 54. The reference signal from the RF reference unit 53 was fed to the second phase detector input of the phase locking electronics 54. CEO frequency sensitivity due to the variation of the drive current was found to be about 4 MHz/W at 200 W pump power.
Figure 9 shows an experimental result obtained with the embodiment of Figure 4. The CEP error measured with the first control loop 50 including the f-to-2f-interferometer and a 4 bit digital phase detector shows a tight locking of the CEP and demonstrates the phase noise around 250 mrad measured in the 1 Hz to 1 MHz bandwidth.
The pulse laser device 100 of Figure 5 comprises one modulated laser diode 21 and one stable laser diode 23, the beam combiner 42, the collimating optics 44 and the thin-disk laser medium 10 as shown in Figure 4. Furthermore, according to Figure 5, the pulse laser device 100 includes a second control loop 60 (intensity noise loop) for an intensity feedback control of the modulated laser diode 21. The second control loop 60 includes an oscillator noise detection unit 61, a voltage reference source 63 and a PID controller 62, which is arranged for controlling the drive current of the modulated laser diode 21. The oscillator noise detection unit 61 detects intensity fluctuations of the output pulses of the pulse laser device 100 relative to a reference voltage provided by the voltage reference source 63. The error signal from the PID controller 62 is fed to the current source of the modulated laser diode 21. Advantageously, the second control loop 60 allows a reduction of intensity noise fluctuations, which could be introduced by a residual noise of the stabilized laser diode or oscillator itself.
According to Figure 6, the pulse laser device 100 includes both the first control loop 50 and additionally the second control loop 60 for oscillator intensity noise compensation. As described with reference to Figure 3, the pulse laser device 100 includes first and second modulated laser diodes 21, 22 and a stable laser diode 23. The pump laser diodes 21, 22 and 23 emit at different wavelengths λ _1, λ _2 and λ _3, which are selected in dependency on the absorption maxima of the laser medium 10. The output of the pump laser diodes 21, 22 and 23 is combined with two steps using the fiber beam combiners 41, 42. The combined output is directed with collimating optics 44 to the laser medium 10. The first control loop 50 is configured with the components 51 to 54 and controls the first modulated laser diode 21 as described with reference to Figure 3. The second control loop 60 is configured with the components 61 to 63 and controls the second modulated laser diode 22 as described with reference to Figure 4.
Figures 7 and 8 show further embodiments of the invention, wherein the first control loop 50 or the second control loop is provided with the embodiment of the pulse laser device 100 as shown in Figure 2. Again, the beam combiners 42 in Figures 7 and 8 comprise monolithic all-fiber beam combiners, which superimpose the output from the pump laser diodes by a direct connection of the output fibers. As a further alternative, both of the first and second control loops 50, 60 can be provided with the fibre coupled embodiment of Figure 2, preferably if two separate modulated laser diodes are provided. | 9. Pulse laser device (100), being adapted for creating output pulses, in particular having a controlled carrier-envelope phase and/or intensity noise, comprising - a thin-disk laser medium (10), and - multiple pump laser diodes (21, 22, 23) being arranged for pumping the thin-disk laser medium (10) and including at least one modulated laser diode (21, 22), which is connected with a current source (31, 32) with modulation capability, wherein - the current source (31, 32) with modulation capability is arranged for modulating a drive current of the respective modulated laser diode (21, 22), so that the output pulses can be controlled by modulating the output power of the at least one modulated laser diode (21, 22),: characterized in that - the pump laser diodes further comprise at least one stable laser diode (23), which is connected with a stabilized current source (33), and - the at least one modulated laser diode (21, 22) and the related current source (31, 32) with modulation capability are configured such that the output power of the at least one modulated laser diode (21, 22) is smaller than the whole output power of the at least one stable laser diode (23). | 10. Pulse laser device according to claim 9, including - a beam combiner (41, 43) which is configured for a free space beam combination of the output of the at least one stable laser diode and the output of the at least one modulated laser diode, or - a fiber beam combiner (42) which is configured for an integrated fiber combination of the output of the at least one stable laser diode and the output of the at least one modulated laser diode.
11. Pulse laser device according to one of the claims 9 or 10, including at least one of the features - the at least one modulated laser diode (21, 22) and the related current source (31, 32) with modulation capability are configured such that a modulation depth of the output power of the modulated laser diode (21, 22) is at least 2 % of the whole output power of the at least one stable laser diode (23), and - the at least one modulated laser diode (21, 22) and the related current source (31, 32) with modulation capability are configured such that a modulation depth of the output power of the modulated laser diode (21, 22) is at most 20 % of a pump power absorbed by the thin-disk laser medium (10), and - the current source (31, 32) with modulation capability is arranged for modulating the drive current of the at least one modulated laser diode (21, 22), so that an oscillator intensity noise of the output pulses can be controlled by modulating the output power of the at least one modulated laser diode (21, 22).
12. Pulse laser device according to one of the claims 9 to 11, including at least one of the features - the current source (31, 32) with modulation capability is adapted for an analogue control of the at least one modulated laser diode (21, 22), - the current source (31, 32) with modulation capability is adapted for a broadband control of the at least one modulated laser diode (21, 22), - the at least one stable laser diode (23) and the at least one modulated laser diode (21, 22) have different output wavelengths selected in accordance to absorption maxima of the thin-disk laser medium (10), - the at least one stable laser diode (23) and the at least one modulated laser diode (21, 22) are configured for emitting laser light with different polarizations, and - the at least one stable laser diode (23) and the at least one modulated laser diode (21, 22) are fiber coupled and combined with a fiber beam combiner (42).
13. Pulse laser device according to one of the claims 9 to 12, including - a first control loop (50) for controlling the carrier-envelope phase of the output pulses, wherein the drive current of the at least one modulated laser diode (21, 22) is controlled in dependency on a detected carrier-envelope offset frequency of the output pulses and a radiofrequency reference signal.
14. Pulse laser device according to one of the claims 9 to 13, including - a second control loop (60) for controlling the intensity noise of the output pulses, wherein the drive current of the at least one modulated laser diode (21, 22) is controlled in dependency on a detected oscillator noise.
15. Pulse laser device according to claim 13 and 14, wherein - the pump laser diodes include at least two modulated laser diodes (21, 22), - the first control loop (50) is used for controlling a first one (21) of the two modulated laser diodes (21, 22), and - the second control loop (60) is used for controlling a second one (22) of the two modulated laser diodes (21, 22). |
2871507 | Beam steering mirror device | 1 | Based on the following detailed description of an invention, generate the patent claims. There should be 9 claims in total. The first, independent claim is given and the remaining 8 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | In the following, functionally similar or identical elements may have the same reference numerals. Absolute values are shown below by way of example only and should not be construed as limiting the invention.
Figure 1 shows in a perspective view a beam steering mirror device 10 with a fine steering mechanism according the present invention. The device 10 is built into a very compact housing consisting of a cover 36 with an opening for the mirror, an upper housing part 38 carrying the mirror mechanism with motors and sensors and a lower housing part 40 for completing the entire device housing. The upper housing part 38 further comprises mounting structures 42 for fixing the device 10 for example at a Laser-based terminal or payload. Electrical connection cables 44 for the motors and sensors of the mirror mechanism leave the housing through openings between the upper and lower parts 38 and 40, respectively.
In the center of the mechanical housing of the device 10, a lightweight mirror 12 made from beryllium and as shown in Figure 2 is suspended by a set of four flex pivots (not shown in Figure 2 ). The integral mirror 12 comprises an optical part 14 and a mirror body 18 for suspending the mirror in the housing and carrying parts of the motors for moving the mirror 12. The optical part 14 is shaped like an essentially circular disk with one disk side forming the optical or reflecting surface 16 and with the opposite side 17 having a mushroom-shaped isostatic design in order to thermally de-couple the optical part 14 from the mirror 18, as it is shown in the side view of the mirror 12 on the left side of Figure 2. In the side view of the mirror 12, also the two rotation axes 22 and 24 are shown, which are arranged essentially perpendicular with respect to each other and located in a common plane. On the right side in Figure 2, the mirror 12 is shown in a perspective view with the openings 20 and 21 for the biaxial suspension of the mirror 12 by means of flexible pivots. For each of the two rotation axes 22 and 24, two pivots on opposite sides of the mirror body 18 are provided. The openings 20 and 21 serve as seats for the flexible pivots. The mirror 12 itself is balanced so that its center of mass is located in the intersection point of the two rotation axes 22 and 24. The mirror body 18 forming the rotating part of the beam steering mechanism also carries four spherically shaped motor magnets 30 (shown in Figure 3 ) of four motors 28 for motion around the two rotation or tilt axes 22 and 24.
Figure 3 shows the internal design of the beam steering mirror device 10 from Figure 1 in detail. As can be seen, the motor stators (coils) 32 of the four motors 28 of the mechanism are mounted in the upper housing part 38, for example in the housing's corners and are located opposite to the four spherically shaped motor magnets 30, which are carried by the mirror body 18. For each rotation axis, respective two motors 28 are provided and coupled in series so that no lateral forces can act during operation of the two motors on the mirror 12 and only a torque around the center of rotation is generated. Due to the concave spherical configuration of the motor stator coils 32, which complies with the shape of the convex motor rotor magnets 30, non-linearity effects due to air gap variations over the rotation angle of the mirror 12 can be avoided for nearly all combinations of rotation axes.
A high resolution eddy current sensor 34 is arranged in line with each motor 28 at the base 46 of the beam steering mirror mechanism, which is fixed at the upper housing part 38. The base 46 also carries the motor stators 32 and partly the flexible pivots 26 of the biaxial suspension of the mirror body 18.
The sensors 34 are temperature-compensated and can be operated in a differential mode (differential read-out) to avoid measurement errors due to thermal influences. The sensors 34 allow a differential angle measurement of the rotation or tilting of the mirror 12 around its rotation axes 22 and 24. The measurements can be processed by an electronic controller (not shown) of the device 10 for controlling the electrical motors supply.
The steering mirror mechanism according to the present invention allows improving the performance of a beam steering mirror device with regard to steering precision and control bandwidth compared to other existing beams steering mirror concepts.
#### Reference Numerals And Acronyms
- 10: beam steering mirror device
- 12: integral mirror, balanced, optical surface with isostatic support
- 14: optical part of the mirror 12
- 16: optical surface of the optical part 14
- 17: mushroom-shaped isostatic side
- 18: mirror body
- 20, 21: biaxial suspension
- 22: first rotation axis
- 24: second rotation axis
- 26: flexible pivot
- 28: motor
- 30: ball shaped (spherically shaped) motor rotor (magnet)
- 32: ball shaped (convex shaped) motor stator (coil)
- 34: high resolution eddy current sensor
- 36: cover of the device housing with opening for mirror
- 38: upper part of the device housing
- 40: lower part of the device housing
- 42: mounting structure of the device
- 44: electrical connection cables for motors 28 and sensors 34
- 46: base of the beam steering mirror mechanism
- FSM: Fine Steering Mechanism
- KHz: kilohertz | 1. A beam steering mirror device (10) comprising - a mirror (12) comprising an optical part (14) with a reflecting or optical surface (16) and a mirror body (18), wherein the optical part is essentially thermally de-coupled from the body, and - a biaxial suspension (20) of the mirror body having two rotation axes (22, 24) being arranged essentially perpendicular with respect to each other and being located in a common plane, wherein - the suspension comprises a set of four flexible pivots (26) with a pair of pivots assigned to each rotation axis, wherein - the mirror is arranged with regard to the biaxial suspension such that its center of mass is approximately located in the intersection point of the two rotation axes, further comprising - motors (28, 30, 32) for moving of the mirror body around the two rotation axes, - sensors (34) for determining the tilting angle of the mirror, and - a housing (36) for the mirror, the biaxial suspension, the motors and the sensors. | 2. The device of claim 1, wherein the optical part (14) has a mushroom-shaped isostatic design on the side (17) opposite to the reflecting or optical surface (16) and is coupled with this side to the mirror body.
3. The device of claim 1 or 2, wherein the mirror body carries four motor magnets, each forming a part of one of four motors.
4. The device of claim 3, wherein the motor stators are mounted in the housing with each motor stator located opposite to the one of the four motor magnets.
5. The device of claim 4, wherein: the motor magnets are spherically convex shaped and the motor stators are concave shaped, and wherein the motor magnets are pivot-suspended and oriented with respect to the motor stators.
6. The device of any of the preceding claims, wherein respective two motors provided for motion of the mirror body around an axis are coupled in series.
7. The device of any of the preceding claims, wherein - four sensors are provided, - the four sensors are arranged in line with the motors in the housing, - the four sensors are eddy current sensors and temperature compensated, and - respective two sensors provided for determining the tilting angle of the mirror around an axis are operated in a differential mode.
8. The device of any of the preceding claims, wherein the mirror is made from beryllium or similar material such as AlBeMet.
9. A Laser-based terminal or payload comprising a beam steering mirror device of any of the preceding claims. |
2871455 | Pressure sensor | 1 | Based on the following detailed description of an invention, generate the patent claims. There should be 8 claims in total. The first, independent claim is given and the remaining 7 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | The term "pressure sensor" as used herein designates any type of sensor measuring a parameter that is equal to or derived from the pressure of a fluid. In particular, the term designates relative (i.e. differential) as well as absolute pressure sensors, it also covers static as well as dynamic pressure sensors. Typical examples of applications of such sensors are e.g. in scientific instrumentation, meteorology, altitude measurement, sound recording, mobile or portable computers and phones etc.
Figure 1 shows a schematic sectional view of a pressure sensor in accordance with an embodiment of the present invention.
The pressure sensor includes a first substrate 1 and a cap 4 for the first substrate 1. The first substrate 1 is a semiconductor substrate, e.g. a silicon substrate, with a front side 11 and a back side 12. The semiconductor substrate 1 includes bulk material 13 such as silicon, and a stack of layers collectively referred to as 14 on the bulk material 13. These layers 14 may be arranged for CMOS processing of the substrate 1, and as such may also be denoted as CMOS layers or material layers. Specifically, the layers 14 can include for example a plurality of SiO2 layers, metal or polysilicon layers. The bulk material 13 may contain doped regions (not shown) within the silicon. These components can form active circuitry, such as amplifiers, A/D converters or other analog and/or digital signal processing units. The top layer of the stack of layers 14 may be a dielectric layer of silicon oxide and/or silicon nitride protecting the structures below it. In the present example, it is assumed that a processing circuit (not further shown) is integrated on the front side 11 of the substrate 1 by means of CMOS processing.
The substrate 1 contains vias 15 reaching vertically through the substrate 1. Those vias 15 provide for an electrical connection from the front side 11 of the substrate 1 to its backside 12. Those vias 15 are manufactured by etching or drilling holes into the substrate 1 from its backside 12, by applying an oxide 151 to the hole, and by applying conducting material 152 to the oxide 151. At the back side 12 of the substrate 1, the vias 15 are electrically connected to contact pads 16 residing on an oxide layer 17 applied to the bulk material 13, which contact pads 16 serve as support for solder balls 18 for electrically connecting the pressure sensor to the outside world. Alternative to the vias 15 and the solder balls 18, there may be other ways of interconnecting the pressure sensor to the outside world, e.g. by means of wire bonds, bond pads or a conducting structures that lead from the front side 11 of the first substrate 1 along its sides to the backside 12. The electrical connection to the outside world may also be implemented via one or more of a Land Grid Array, a Pin Grid Array, or a leadframe.
The cap 4 contains a container 41 and a holder 42 for the container 41. Suspension elements not shown in the present illustration are provided for suspending the container 41 from the holder 42. The holder 42 preferably encircles the container 41 in a plane of the cap 4.
Parts of the container 41 and the holder 42 are made from a second substrate 2. The second substrate 2 is a semiconductor substrate, preferably a silicon substrate, and has a front side 21 and a backside 22. The second substrate 2 again contains a bulk material 23 of silicon and a stack of layers 24 on the bulk material 23. Specifically, the stack of layers 24 may include oxide layers 241 and 242, and a polysilicon layer 243.
The container 41 is separated from the holder 42 by grooves 43 that alternate with the suspension elements around the container 41. Owed to the manufacturing of the container 41 and the holder 42 from the common second substrate 2, both components include bulk material 23 from the second substrate 2 as well as the layer stack 24. In the container 41, a cavity 411 is formed by omitting or removing material from one or more of the layers 24. The cavity 411 is closed by a deformable membrane 412. The membrane 412 is sufficiently thin such that it deforms depending on a pressure drop between a pressure at the top of the membrane 412 and below it. The polysilicon layer 243 in the container 41 may be used as an electrode. The membrane 412 preferably is formed by a doped, conducting silicon layer, is arranged as a sealing lid over the cavity 411, and may be used as another electrode for which reason the deformable membrane 412 may contain electrically conducting material. Hence upon a change in pressure the membrane 412 deflects and as such a distance between the two electrodes changes which results in a change of the capacitance between the two electrodes. Corresponding signals may be transmitted from the electrodes to the holder 42 via the conducting one of the layers 24 that pass through the suspension elements.
In the present example, the deformable membrane 412 is built from a third substrate 3. The third substrate 3 as shown in Figure 1 may be the remainder of an SOI substrate, specifically its device layer after some manufacturing steps. The remainder of the third substrate 3 outside the membrane 412, i.e. the portion that is attached to the layer stack 24 of the holder 42 may contain contact windows 421 there through. At other locations, there may be isolation trenches 422 manufactured in the third substrate 3 for avoiding a short circuit of the membrane 412 with the contact windows 421.
The assembly containing the second and the third substrate 2,3 is attached to the front side 11 of the first substrate 1. The attachment may include bonding or other fusion techniques. In the present example, spacer elements 5 are provided between the third substrate 3 and the first substrate 1. The spacer elements 5 may have different functions: On the one hand, the spacer elements 5 provide for the gap 6 between the deformable membrane 412 and the first substrate 1 which is required for supplying the pressure medium to the membrane 412. On the other hand, some of the spacer elements 5 but not necessarily all may be electrically conductive for connecting the contact windows 421 to contact pads on the front side of the first substrate 1. Other or the same spacer elements 5 may provide mechanical stability for the stacking of substrates 1,3, and / or may provide mechanical protection to the inside of the pressure sensor, and specifically to the membrane 412. For this purpose, it may be preferred, that a spacer element 51 is arranged in from of a ring at the edges of the substrates 1,3 providing mechanical stability, protection as well as an electrical connection, while spacer elements 52 are rather pillar-like and provide electrical connections.
The signals provided by the two electrodes in the container 41 are supplied via suspension elements to the holder 42, via the contact windows 421 and one or more of the spacer elements 5 to the processing circuit of the first wafer 1. From the processing circuit, electrical signals may be supplied via the vias 15 to the solder balls 18.
At the backside 22 of the second substrate 2 the thickness of the bulk material 23 is partially reduced in the region of the container 41. The recess 44 to the backside 22 of the second substrate 2 is preferably etched with the aid of a previously applied hard mask 7. The hard mask 7 in turn is covered by a protection membrane 8 which protects the grooves 43 and the deformable membrane 412 from fluid or particles. The protection membrane 8 preferably is permeable to the pressure medium. A port for conducting the medium to the deformable membrane 412 in the present example encompasses the recess 44, the grooves 43, and the gap 6, or at least parts of.
The overall height of the pressure sensor in the present example is about 400 µm.
Figure 2 illustrates another example of a pressure sensor in a top view in diagram a) and in a side cut in diagram b). The side cut in diagram 2b) is more schematic than the side cut of Figure 1 and for illustration purposes solely shows the first substrate 1 with solder balls 18 attached, the cap 4 attached to the first substrate 1, the cap 4 containing the container 41 and the holder 42, the recess 44 in the cap 4, and the protection membrane 8 covering the recess 43 in the cap 4.
Diagram 2a) illustrates the corresponding top view without the protection membrane 8, and as such illustrates the suspension of the container 41 from the holder 42. Basically, all that can be seen from the top is the second substrate 2 structured for building the container 41 and the holder 42. For this purpose, grooves 43 are arranged vertically through the second substrate 2. The grooves 43 have a shape as shown in Figure 2a ) and as such build suspension elements 45 between the grooves 43 that hold the container 41. The suspension elements 45 are mechanical links between the container 41 and the holder 42, and may allow for a slight displacement of the container 41 in the plane of the cap 4, and especially in the x and y direction.
Figure 3 shows in its diagrams a) to l) schematic cross-sections of a pressure sensor according an embodiment of the present invention during manufacturing thereby illustrating the individual processing steps.
In Figure 3a ) a second substrate 2 is provided with a front side 21 and a back side 22 including a bulk material 23 and layers 24 stacked on the bulk material 23, which layers 24 are only schematically illustrated and may contain oxide layers 241, 242, e.g. SiO2, and a polysilicon layer 243. A cavity 411 is etched into the layers 24, and trenches 25 are etched through the layers 24 into the bulk material 23, e.g. by deep reactive ion etching. The trenches 25 and the cavity 411 may be etched in the same etching step.
In a next step illustrated in Figure 3b ) a third substrate 3 in form of an SOI substrate is attached to the layers 24 of the second substrate 2 at its front side 21 e.g. by fusion bonding. The SOI substrate contains bulk material 31, an insulation layer 32 in form of a BOX layer, and a silicon layer 33 as device layer. As a result, the cavity 411 and the trenches 25 are closed.
In a further step illustrated in Figure 3c ), the bulk material 31 and the insulation layer 32 of the SOI substrate are removed such that the silicon layer 33 remains covering the cavity 411, which silicon layer 33 is thin enough to deflect in response to pressure applied.
In the step illustrated in Figure 3d ), contact windows 421 are etched through the third substrate 3 into the layers 24 of the second substrate 2. In Figure 3e ), the contact windows 421 are metalized and electrically conducting spacer elements 5 are applied to the third substrate 3.
In the step illustrated in Figure 3f ), the silicon layer 33 representing the third substrate 3 is etched for opening the trenches 25 in the second substrate 2, and for generating trenches 422 for electrical isolation. Now, the container 41 and the holder 42 for the container 41 are prepared. The entire assembly including the second and third substrate 2,3 now is flipped and attached to a first substrate 1, see Figure 3g ). The first substrate 1 itself is prefabricated in that a processing circuit (not shown) is integrated in layers 14 stacked on a bulk material 13 at a front side 11 of the first substrate 1.
In a next step as illustrated in Figure 3h ), the second substrate 2 may be thinned from its back side 22 to a reduced thickness in the range of e.g. 100 to 200 microns. This process can be performed using grinding, etching or milling. Afterwards, a hard mask 7 is applied to the backside 22 of the second substrate 2.
In the step illustrated in Figure 3i ), the first substrate 1 is processed: Vias 15 are manufactured through the first substrate 1, and solder balls 18 are attached to the backside 12 of the first substrate 1. In the step illustrated in Figure 3j ), the entire assembly is placed on a BGA (Ball Grid Array) protective foil 9. In the step illustrated in Figure 3k ), the backside 22 of the second substrate 2 is etched by using the hard mask 7. The recess 44 etched therein is deep enough to lay open the trenches 25 previously formed in the second substrate 2. In the step illustrated in Figure 3l ), a protective membrane 8 is applied to cover the recess 44.
Generally, instead of a protective membrane a hard layer may be applied containing an access opening contributing to the port. However, there may be alternative pressure sensors where neither a membrane nor any other protection means is required subject to the application and the design of the pressure sensor.
It should further be noted that in any removal of material during manufacturing, the corresponding structures may be created using a chemical (wet) etching process, plasma etching process, laser cutting, mechanical milling or a combination of any of these processes, where suitable. | 1. A pressure sensor, comprising: a first substrate (1) containing a processing circuit integrated thereon,: a cap (4) attached to the first substrate (1) wherein the cap (4) includes a container (41), a holder (42), and one or more suspension elements (45) for suspending the container (41) from the holder (42), the container (41) including a cavity (411) and a deformable membrane (412) separating the cavity (411) and a port open to an outside of the pressure sensor, the container (41) being suspended from the holder (42) such that the deformable membrane (412) faces the first substrate (1) and such that a gap (6) is provided between the deformable membrane (412) and the first substrate (1) which gap (6) contributes to the port, and: sensing means for converting a response of the deformable membrane (412) to pressure at the port into a signal capable of being processed by the processing circuit. | 2. The sensor of claim 1,: wherein the cap (4) has a plane extension and wherein the holder (42) encircles the container (41) in the plane of the cap (4),: wherein between the holder (42) and the container (41) the one or more suspension elements (45) and one or more grooves (43) alternate.
3. The sensor of claim 1 or claim 2,: wherein each suspension element (45) contains a ridge between the holder (42) and the container (41), and: wherein each suspension element (45) has a shape allowing for a deviation of the container (41) in at least one direction in the plane of the cap (4).
4. The sensor of claim 2 or claim 3,: wherein a height of the container (41) is less than a height of the holder (42) orthogonal to the plane of the cap (4) thereby forming a recess (44) on a backside of the cap (4) opposite to the side of the cap (4) the deformable membrane (412) is arranged, and: in particular wherein the recess (44) is covered by a protection membrane (8).
5. The sensor of claim 2,: wherein the first substrate (1) is a semiconductor substrate,: wherein the cap (4) contains a second substrate (2) and each groove (43) is arranged orthogonal to the plane of the cap (4) in the second substrate (2) for separating the container (41) from the holder (42).
6. The sensor of claim 5,: wherein the second substrate (2) contains a bulk material (23) and layers (24) stacked on the bulk material (23),: wherein the cavity (411) is a recess exclusively arranged in one or more of the layers (24) of the second substrate (2),: wherein the deformable membrane (412) is made from a third substrate (3) attached to the layers (24) of the second substrate (2), and: wherein the one or more grooves (43) extend into the third substrate (3) for separating the deformable membrane (412) from a portion of the third substrate (3) contributing to the holder (42).
7. The sensor of claim 6,: wherein the sensing means contains a first electrode formed by the deformable membrane (412) and a second electrode formed by one of the layers (24) of the second substrate (2), and: in particular wherein the second electrode is made of polysilicon.
8. The sensor of claim 7,: : comprising at least two electrical connections between the cap (4) and the first substrate (1),: wherein the first electrode is electrically connected to the processing circuit via at least one of the suspension elements (45) and at least one of the electrical connections,: wherein the second electrode is electrically connected to the processing circuit via at least another one of the suspension elements (45) and at least another one of the electrical connections, and: in particular wherein spacer elements (5) are arranged between the first substrate (1) and the third or the second substrate (3,2) for building the gap (6), and wherein the electrical connections are provided by at least some of the spacer elements (5). |
2871455 | Pressure sensor | 2 | Based on the following detailed description of an invention, generate the patent claims. There should be 8 claims in total. The first, independent claim is given and the remaining 7 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | The term "pressure sensor" as used herein designates any type of sensor measuring a parameter that is equal to or derived from the pressure of a fluid. In particular, the term designates relative (i.e. differential) as well as absolute pressure sensors, it also covers static as well as dynamic pressure sensors. Typical examples of applications of such sensors are e.g. in scientific instrumentation, meteorology, altitude measurement, sound recording, mobile or portable computers and phones etc.
Figure 1 shows a schematic sectional view of a pressure sensor in accordance with an embodiment of the present invention.
The pressure sensor includes a first substrate 1 and a cap 4 for the first substrate 1. The first substrate 1 is a semiconductor substrate, e.g. a silicon substrate, with a front side 11 and a back side 12. The semiconductor substrate 1 includes bulk material 13 such as silicon, and a stack of layers collectively referred to as 14 on the bulk material 13. These layers 14 may be arranged for CMOS processing of the substrate 1, and as such may also be denoted as CMOS layers or material layers. Specifically, the layers 14 can include for example a plurality of SiO2 layers, metal or polysilicon layers. The bulk material 13 may contain doped regions (not shown) within the silicon. These components can form active circuitry, such as amplifiers, A/D converters or other analog and/or digital signal processing units. The top layer of the stack of layers 14 may be a dielectric layer of silicon oxide and/or silicon nitride protecting the structures below it. In the present example, it is assumed that a processing circuit (not further shown) is integrated on the front side 11 of the substrate 1 by means of CMOS processing.
The substrate 1 contains vias 15 reaching vertically through the substrate 1. Those vias 15 provide for an electrical connection from the front side 11 of the substrate 1 to its backside 12. Those vias 15 are manufactured by etching or drilling holes into the substrate 1 from its backside 12, by applying an oxide 151 to the hole, and by applying conducting material 152 to the oxide 151. At the back side 12 of the substrate 1, the vias 15 are electrically connected to contact pads 16 residing on an oxide layer 17 applied to the bulk material 13, which contact pads 16 serve as support for solder balls 18 for electrically connecting the pressure sensor to the outside world. Alternative to the vias 15 and the solder balls 18, there may be other ways of interconnecting the pressure sensor to the outside world, e.g. by means of wire bonds, bond pads or a conducting structures that lead from the front side 11 of the first substrate 1 along its sides to the backside 12. The electrical connection to the outside world may also be implemented via one or more of a Land Grid Array, a Pin Grid Array, or a leadframe.
The cap 4 contains a container 41 and a holder 42 for the container 41. Suspension elements not shown in the present illustration are provided for suspending the container 41 from the holder 42. The holder 42 preferably encircles the container 41 in a plane of the cap 4.
Parts of the container 41 and the holder 42 are made from a second substrate 2. The second substrate 2 is a semiconductor substrate, preferably a silicon substrate, and has a front side 21 and a backside 22. The second substrate 2 again contains a bulk material 23 of silicon and a stack of layers 24 on the bulk material 23. Specifically, the stack of layers 24 may include oxide layers 241 and 242, and a polysilicon layer 243.
The container 41 is separated from the holder 42 by grooves 43 that alternate with the suspension elements around the container 41. Owed to the manufacturing of the container 41 and the holder 42 from the common second substrate 2, both components include bulk material 23 from the second substrate 2 as well as the layer stack 24. In the container 41, a cavity 411 is formed by omitting or removing material from one or more of the layers 24. The cavity 411 is closed by a deformable membrane 412. The membrane 412 is sufficiently thin such that it deforms depending on a pressure drop between a pressure at the top of the membrane 412 and below it. The polysilicon layer 243 in the container 41 may be used as an electrode. The membrane 412 preferably is formed by a doped, conducting silicon layer, is arranged as a sealing lid over the cavity 411, and may be used as another electrode for which reason the deformable membrane 412 may contain electrically conducting material. Hence upon a change in pressure the membrane 412 deflects and as such a distance between the two electrodes changes which results in a change of the capacitance between the two electrodes. Corresponding signals may be transmitted from the electrodes to the holder 42 via the conducting one of the layers 24 that pass through the suspension elements.
In the present example, the deformable membrane 412 is built from a third substrate 3. The third substrate 3 as shown in Figure 1 may be the remainder of an SOI substrate, specifically its device layer after some manufacturing steps. The remainder of the third substrate 3 outside the membrane 412, i.e. the portion that is attached to the layer stack 24 of the holder 42 may contain contact windows 421 there through. At other locations, there may be isolation trenches 422 manufactured in the third substrate 3 for avoiding a short circuit of the membrane 412 with the contact windows 421.
The assembly containing the second and the third substrate 2,3 is attached to the front side 11 of the first substrate 1. The attachment may include bonding or other fusion techniques. In the present example, spacer elements 5 are provided between the third substrate 3 and the first substrate 1. The spacer elements 5 may have different functions: On the one hand, the spacer elements 5 provide for the gap 6 between the deformable membrane 412 and the first substrate 1 which is required for supplying the pressure medium to the membrane 412. On the other hand, some of the spacer elements 5 but not necessarily all may be electrically conductive for connecting the contact windows 421 to contact pads on the front side of the first substrate 1. Other or the same spacer elements 5 may provide mechanical stability for the stacking of substrates 1,3, and / or may provide mechanical protection to the inside of the pressure sensor, and specifically to the membrane 412. For this purpose, it may be preferred, that a spacer element 51 is arranged in from of a ring at the edges of the substrates 1,3 providing mechanical stability, protection as well as an electrical connection, while spacer elements 52 are rather pillar-like and provide electrical connections.
The signals provided by the two electrodes in the container 41 are supplied via suspension elements to the holder 42, via the contact windows 421 and one or more of the spacer elements 5 to the processing circuit of the first wafer 1. From the processing circuit, electrical signals may be supplied via the vias 15 to the solder balls 18.
At the backside 22 of the second substrate 2 the thickness of the bulk material 23 is partially reduced in the region of the container 41. The recess 44 to the backside 22 of the second substrate 2 is preferably etched with the aid of a previously applied hard mask 7. The hard mask 7 in turn is covered by a protection membrane 8 which protects the grooves 43 and the deformable membrane 412 from fluid or particles. The protection membrane 8 preferably is permeable to the pressure medium. A port for conducting the medium to the deformable membrane 412 in the present example encompasses the recess 44, the grooves 43, and the gap 6, or at least parts of.
The overall height of the pressure sensor in the present example is about 400 µm.
Figure 2 illustrates another example of a pressure sensor in a top view in diagram a) and in a side cut in diagram b). The side cut in diagram 2b) is more schematic than the side cut of Figure 1 and for illustration purposes solely shows the first substrate 1 with solder balls 18 attached, the cap 4 attached to the first substrate 1, the cap 4 containing the container 41 and the holder 42, the recess 44 in the cap 4, and the protection membrane 8 covering the recess 43 in the cap 4.
Diagram 2a) illustrates the corresponding top view without the protection membrane 8, and as such illustrates the suspension of the container 41 from the holder 42. Basically, all that can be seen from the top is the second substrate 2 structured for building the container 41 and the holder 42. For this purpose, grooves 43 are arranged vertically through the second substrate 2. The grooves 43 have a shape as shown in Figure 2a ) and as such build suspension elements 45 between the grooves 43 that hold the container 41. The suspension elements 45 are mechanical links between the container 41 and the holder 42, and may allow for a slight displacement of the container 41 in the plane of the cap 4, and especially in the x and y direction.
Figure 3 shows in its diagrams a) to l) schematic cross-sections of a pressure sensor according an embodiment of the present invention during manufacturing thereby illustrating the individual processing steps.
In Figure 3a ) a second substrate 2 is provided with a front side 21 and a back side 22 including a bulk material 23 and layers 24 stacked on the bulk material 23, which layers 24 are only schematically illustrated and may contain oxide layers 241, 242, e.g. SiO2, and a polysilicon layer 243. A cavity 411 is etched into the layers 24, and trenches 25 are etched through the layers 24 into the bulk material 23, e.g. by deep reactive ion etching. The trenches 25 and the cavity 411 may be etched in the same etching step.
In a next step illustrated in Figure 3b ) a third substrate 3 in form of an SOI substrate is attached to the layers 24 of the second substrate 2 at its front side 21 e.g. by fusion bonding. The SOI substrate contains bulk material 31, an insulation layer 32 in form of a BOX layer, and a silicon layer 33 as device layer. As a result, the cavity 411 and the trenches 25 are closed.
In a further step illustrated in Figure 3c ), the bulk material 31 and the insulation layer 32 of the SOI substrate are removed such that the silicon layer 33 remains covering the cavity 411, which silicon layer 33 is thin enough to deflect in response to pressure applied.
In the step illustrated in Figure 3d ), contact windows 421 are etched through the third substrate 3 into the layers 24 of the second substrate 2. In Figure 3e ), the contact windows 421 are metalized and electrically conducting spacer elements 5 are applied to the third substrate 3.
In the step illustrated in Figure 3f ), the silicon layer 33 representing the third substrate 3 is etched for opening the trenches 25 in the second substrate 2, and for generating trenches 422 for electrical isolation. Now, the container 41 and the holder 42 for the container 41 are prepared. The entire assembly including the second and third substrate 2,3 now is flipped and attached to a first substrate 1, see Figure 3g ). The first substrate 1 itself is prefabricated in that a processing circuit (not shown) is integrated in layers 14 stacked on a bulk material 13 at a front side 11 of the first substrate 1.
In a next step as illustrated in Figure 3h ), the second substrate 2 may be thinned from its back side 22 to a reduced thickness in the range of e.g. 100 to 200 microns. This process can be performed using grinding, etching or milling. Afterwards, a hard mask 7 is applied to the backside 22 of the second substrate 2.
In the step illustrated in Figure 3i ), the first substrate 1 is processed: Vias 15 are manufactured through the first substrate 1, and solder balls 18 are attached to the backside 12 of the first substrate 1. In the step illustrated in Figure 3j ), the entire assembly is placed on a BGA (Ball Grid Array) protective foil 9. In the step illustrated in Figure 3k ), the backside 22 of the second substrate 2 is etched by using the hard mask 7. The recess 44 etched therein is deep enough to lay open the trenches 25 previously formed in the second substrate 2. In the step illustrated in Figure 3l ), a protective membrane 8 is applied to cover the recess 44.
Generally, instead of a protective membrane a hard layer may be applied containing an access opening contributing to the port. However, there may be alternative pressure sensors where neither a membrane nor any other protection means is required subject to the application and the design of the pressure sensor.
It should further be noted that in any removal of material during manufacturing, the corresponding structures may be created using a chemical (wet) etching process, plasma etching process, laser cutting, mechanical milling or a combination of any of these processes, where suitable. | 9. A method for manufacturing a pressure sensor comprising the steps of: providing a first substrate (1) with a processing circuit integrated thereon,: providing a second substrate (2),: providing a third substrate (3),: manufacturing a cavity (411)) in the second substrate (2) and one or more trenches (25) around a first portion of the second substrate (2) containing the cavity (411),: mounting said third substrate (3) to said second substrate (2) thereby covering the cavity (411) in the second substrate (2) to form a deformable membrane (412) for sensing a pressure applied to the deformable membrane (412), and: mounting the assembly of the second substrate (2) and the third substrate (3) to the first substrate (1) with the deformable membrane (412) facing the first substrate (1) and providing a gap (6) between the deformable membrane (412) and the first substrate (1). | 10. The method of claim 9,: wherein manufacturing the cavity (411) in the second substrate (2) includes manufacturing the cavity (411) in one or more layers (24) stacked on a bulk material (23) of the second substrate (2), and: wherein manufacturing the one or more trenches (25) in the second substrate (2) includes manufacturing the one or more trenches (25) through the layers (24) stacked on the bulk material (23) and through at least a portion of the bulk material (23), and: in particular wherein the one or more trenches (25) are manufactured through the entire bulk material (23), and: in particular wherein the one or more trenches (25) are manufactured by etching.
11. The method of claim 9 or claim 10, wherein mounting said third substrate (3) to said second substrate (2) to form the deformable membrane (412) includes attaching a silicon-on-insulator substrate to a top layer of the second substrate (2), removing a bulk material (31) and an insulating layer (32) of the silicon-on-insulator substrate thereby leaving a silicon layer (33) as deformable membrane (412) spanning the cavity (411) in the second substrate (2).
12. The method of claim 11,: wherein mounting said third substrate (3) to said second substrate (2) includes in a portion of the third substrate (3) outside the deformable membrane - etching through the third substrate (3) for manufacturing one or more contact windows (421) in the second substrate (2), - metalizing the one or more contact windows (421), and - laying open the one or more trenches (25) in the second substrate (2) by opening the third substrate (3) at the location of the trenches (25).
13. The method of any one of the preceding claims 9 to 12,: wherein a recess (44) is manufactured in a backside (22) of the second substrate (2) opposite the side the deformable membrane (412) is attached to, which recess (44) is manufactured of a sufficient depth for laying open the one or more trenches (25) previously manufactured into a portion of the bulk material (23) thereby forming one or more grooves (43) through the second substrate (2).
14. The method of claim 13,: wherein after mounting the assembly of the second substrate (2) and the third substrate (3) to the first substrate (1) and prior to manufacturing the recess (44) in the backside (22) of the second substrate (2) the second substrate (2) is thinned and a hard mask (7) is applied to the backside (22) of the second substrate (2) omitting an area for manufacturing the recess (44), and: wherein after having manufactured the recess (44) a protection membrane (8) is applied to the hard mask (7) for covering the recess (44).
15. The method of claim 14,: wherein the gap (6) between the first substrate (1) and the assembly of the second and third substrate (2,3) is manufactured by applying spacer elements (5) between the first substrate (1) and the assembly.
16. The method of any one of the preceding claims 9 to 15,: wherein electrically conducting vias (15) are built through the first substrate (1) for electrically connecting the processing circuit to electrical contact structures on a backside (12) of the first substrate (1) opposite the side facing the deformable membrane (412), and: in particular wherein the vias (15) are built after having mounted the assembly of the second substrate (2) and the third substrate (3) to the first substrate (1) and prior to manufacturing the recess (44) in the backside (22) of the second substrate (2). |
2871456 | Pressure sensor | 1 | Based on the following detailed description of an invention, generate the patent claims. There should be 8 claims in total. The first, independent claim is given and the remaining 7 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | The term "pressure sensor" as used herein designates any type of sensor measuring a parameter that is equal to or derived from the pressure of a fluid. In particular, the term designates relative (i.e. differential) as well as absolute pressure sensors, it also covers static as well as dynamic pressure sensors. Typical examples of applications of such sensors are e.g. in scientific instrumentation, meteorology, altitude measurement, sound recording, mobile or portable computers and phones etc.
Figure 1a ) shows a schematic sectional view of a pressure sensor in accordance with an embodiment of the present invention. The pressure sensor as shown is flipped with its solder balls 18 showing upwards while the pressure sensor will be mounted to a carrier with its solder balls sitting on the carrier.
The pressure sensor includes a first substrate 1 and a cap 4 for the first substrate 1.
The cap 4 preferably is made from a second substrate 2 and a third substrate 3. The second substrate 2 preferably is a semiconductor substrate, preferably a silicon substrate, and has a front side 21 and a backside 22. The second substrate 2 contains a bulk material 23 of, e.g. silicon and a stack of layers 24 on the bulk material 23. These layers 24 may be arranged for CMOS processing of the second substrate 2, and as such may also be denoted as CMOS layers or material layers. Specifically, the layers 24 can include for example a plurality of SiO2 layers, metal or polysilicon layers. The bulk material 23 may contain doped regions within the silicon such as indicated by the reference sign 241. These components can form active circuitry, such as amplifiers, A/D converters or other analog and/or digital signal processing units. A top layer 246 of the stack of layers 24 may be a dielectric layer of silicon oxide and/or silicon nitride protecting the structures below it. In the present example, it is assumed that a processing circuit collectively referred to as 241 is integrated on the front side 21 of the second substrate 2 by means of CMOS processing.
In the cap 4, a cavity 41 is formed by omitting or removing material from one or more of the layers 24, presently the top layer 246. The cavity 41 is closed by a deformable membrane 42. The membrane 42 is sufficiently thin such that it deforms depending on a pressure drop between a pressure at the top of the membrane 42 and below it. A metal layer 243 may be used as an electrode, and as such may be arranged at the bottom of the cavity 41.
The membrane 42 preferably is formed by a doped, conducting silicon layer, is arranged as a sealing lid over the cavity 41, and may be used as another electrode for which reason the deformable membrane 42 may contain electrically conducting material. Hence upon a change in pressure the membrane 42 deflects and as such a distance between the two electrodes changes which results in a change of the capacitance between the two electrodes.
In the present example, the deformable membrane 42 is built from a third substrate 3. The third substrate 3 as shown in Figure 1 may be the remainder of an SOI substrate, specifically its device layer after some manufacturing steps. The third substrate 3 not only may contribute to the deformable membrane 42. The third substrate 3 may contain contact windows 244 reaching through which may also reach into one or more of the layers 24.
Corresponding signals may be transmitted from the electrodes, i.e. the deformable membrane 42 and the metal layer 243 via electrical paths 242 to the processing circuit 241 where these signals are processed. Signals processed by the processing circuit 241 may be supplied to the first substrate 1.
The first substrate 1 may be a semiconductor substrate, e.g. a silicon substrate, or a glass substrate, for example, with a front side 11 and a back side 12. The semiconductor substrate 1 includes bulk material 13 such as silicon, and one or more layers 14, such as an oxide layer on the bulk material 13. The one or more layers 14 may further include for example a plurality of SiO2 layers, metal or polysilicon layers.
The first substrate 1 contains vias 15 reaching vertically through the first substrate 1. Those vias 15 provide for an electrical connection from the front side 11 of the substrate 1 to its backside 12. Those vias 15 are manufactured by etching or drilling holes into the first substrate 1 from its backside 12, by applying an oxide 151 to the hole, and by applying conducting material 152 to the oxide 151. At the back side 12 of the first substrate 1, the vias 15 are electrically connected to contact pads 16 residing on an oxide layer 17 applied to the bulk material 13, which contact pads 16 serve as support for solder balls 18 or other contact means for electrically connecting the pressure sensor to the outside world, i.e. to another device. Alternative to the vias 15 and the solder balls 18, there may be other ways of interconnecting the pressure sensor to the outside world, e.g. by means of wire bonds, bond pads or conducting structures that lead from the front side 11 of the first substrate 1 along its sides to the backside 12. The electrical connection to the outside world may also be implemented via one or more of a Land Grid Array, a Pin Grid Array, or a leadframe.
The assembly containing the second and the third substrate 2,3 is attached to the front side 11 of the first substrate 1. The attachment may include bonding or other fusion techniques. In the present example, spacer elements 5 are provided between the third substrate 3 and the first substrate 1. The spacer elements 5 may have different functions: On the one hand, the spacer elements 5 provide for a gap 6 between the deformable membrane 42 and the first substrate 1 which is required for supplying the pressure medium to the membrane 42. On the other hand, some of the spacer elements 5, but not necessarily all may be electrically conductive for connecting the contact windows 244 to the first substrate 1. Other or the same spacer elements 5 may provide mechanical stability for the stacking of substrates 1,3, and / or may provide mechanical protection to the inside of the pressure sensor, and specifically to the membrane 42. For this purpose, it may be preferred, that a spacer element 51 is arranged in from of a ring at the edges of the substrates 1,3 providing mechanical stability, protection as well as an electrical connection, while spacer elements 52 are rather pillar-like and provide electrical connections.
The signals provided by the processing circuit 241 hence may be transferred via one or more of the electrical paths 242 and via one or more of the contact windows 244 to one or more of the spacer elements 5. As shown in Figure 1, the spacer elements 52 end at the vias 15 of the first substrate 1 and are electrically connected thereto. Hence, the signals are conducted through the vias 15 to the contact pads 16 and the solder balls 18.
The first substrate 1 contains a support portion 7 and a contact portion 8. Suspension elements not shown in the present illustration are provided for suspending the support portion 7 from the contact portion 8. The support portion 7 preferably encircles the contact portion 8 in a plane of the first substrate 1.
The contact portion 8 is separated from the support portion 7 by one or more grooves 10. Owed to the manufacturing of the contact portion 8 and the support portion 7 from the common first substrate 1, both portions may include bulk material 13 from the first substrate 1.
The cap 4 preferably is exclusively attached to the support portion 7 of the first substrate 1 via the spacer elements 5. On the other hand, it is preferred that it is solely the contact portion that provides a mechanical and electrical contact to the outside world. Hence, the portion of the pressure sensor via which mechanical stress is induced, i.e. the contact portion 8 is mechanically decoupled from the rest of the pressure sensor and specifically from the deformable membrane 42 by way of the suspension elements.
A port for conducting a medium to the deformable membrane 42 in the present example encompasses the the grooves 10 and the gap 6, or at least parts of.
The overall height of the pressure sensor in the present example is about 400 µm.
Figure 1b ) illustrates a representative horizontal cut of a pressure sensor, e.g. according to line A-A' in Figure 1a ) not necessarily matching all elements as provided in Figure 1a ). A mechanical support 32 holds the third substrate 3. In the third substrate 3, a plurality of contact windows 244 are provided which contain electrically conducting material 2441 in their interior. The third substrate 3 also builds the deformable membrane 42. Then, the horizontal cut switches to a different plane, i.e. the plane of the electrode 243. This electrode 243 is surrounded by the cavity 41.
Figure 1c ) illustrates a bottom view onto the first substrate 1 of the pressure sensor. The first substrate 1 contains a support portion 7 and a contact portion 8 wherein the support portion 7 is suspended from the contact portion 8 by means of a suspension element 9, which is a representation of a mechanical link between the two portions 7 and 8. A groove 10 is arranged vertically through the first substrate 1. Vias 15 are arranged in the support portion 7, while the solder balls 18 are arranged in the contact portion 8. The contact portion 8 is electrically connected to the support portion 7 by means of electrically conducting structures such as the contact pads 16 which electrically conducting structures may in generally be denoted as redistribution layer.
Figure 2 shows in its diagrams a) to d) schematic cross-sections of a pressure sensor according an embodiment of the present invention during manufacturing thereby illustrating the individual processing steps. In Figure 2a ) a preprocessed second substrate 2 is shown with a front side 21 and a back side 22 including a bulk material 23 and layers 24 stacked on the bulk material 23, which layers 24 are only schematically illustrated and may contain oxide layers, e.g. SiO2, metal layers, and / or polysilicon layers such as layer 243 serving as electrode, and a top layer 246 serving as passivation layer. A processing circuit 241 is integrated into the second substrate 2, e.g. by doping the bulk material 23 and / or by structuring the layer stack 24. In addition, a cavity 41 is etched into the layers 24, and preferably into the top layer 246.
In a next step, the deformable membrane 42 is built on the preprocessed substrate 2. For this purpose, a third substrate 3 in form of an SOI substrate is attached to the layers 24 of the second substrate 2 at its front side 21 e.g. by fusion bonding. The SOI substrate may contain bulk material, an insulation layer in form of a BOX layer, and a silicon layer as device layer. As a result, the cavity 41 is closed. In a further step not explicitly shown in the Figures, the bulk material and the insulation layer of the SOI substrate are removed such that the silicon layer remains as third substrate 3 covering the cavity 41, which silicon layer is thin enough to deflect in response to pressure applied.
In a next step, contact windows 244 are etched through the third substrate 3 into the layers 24 of the second substrate 2. The contact windows 244 are metalized and spacer elements 51 and 52 are applied to the third substrate 3.
In a next step illustrated in Figure 2b ), a preprocessed first substrate 1 is attached to the assembly of the second and the third substrate 2, 3. The first substrate 1 is preprocessed, for example, according to the diagrams of Figure 3.
In the diagram of Figure 3a ) a first substrate 1 is provided, e.g. a semiconductor substrate such as a silicon substrate. At its top side, one or more layers 14 are arranged, such as CMOS layers, or simply an isolation layer such as a silicon-oxide layer. In an additional step shown in Figure 3b ), spacer elements 51 and 52 are arranged at the front side 11 of the first substrate 1. In the step shown in Figure 3c ), trenches 101 are etched into the bulk material 13 of the first substrate thereby penetrating the layers 14, e.g. by deep reactive ion etching.
The first substrate 1 preprocessed according to Figure 3c ) then is applied to the assembly of the preprocessed second and third substrate 2, 3 according to Figure 2a ) thereby resulting in an assembly according to Figure 2b ).
In a next step as illustrated in Figure 2c ), the first substrate 1 is thinned from its backside 11 to a reduced thickness in the range of e.g. 100 to 200 microns. This process can be performed using grinding, etching or milling.
In the step illustrated in Figure 2d ), the first substrate 1 is continued to be processed: Vias 15 are manufactured through the first substrate 1. Preferably in a step following the manufacturing of the vias 15, the trenches 101 in the first substrate 1 are opened from the backside 12 of the first substrate 1, e.g. by way of etching such that one or more grooves 10 are now provided reaching through the first substrate 1. In a last step, solder balls 18 or other contact structures may be attached to the backside 12 of the first substrate 1. The result is shown in Figure 1.
By having manufactured the one or more grooves 10, the first substrate 1 is separated into a support portion 7 to which the cap 4 is attached, and a contact portion 8 via which the pressure sensor is electrically connected to another device.
It should further be noted that in any removal of material during manufacturing, the corresponding structures may be created using a chemical (wet) etching process, plasma etching process, laser cutting, mechanical milling or a combination of any of these processes, where suitable. | 1. A pressure sensor, comprising: a first substrate (1),: a cap (4) attached to the first substrate (1) wherein the cap (4) includes a processing circuit (241), a cavity (41) and a deformable membrane (42) separating the cavity (41) and a port open to an outside of the pressure sensor, and: sensing means for converting a response of the deformable membrane (42) to pressure at the port into a signal capable of being processed by the processing circuit (241),: wherein the cap (4) is attached to the first substrate (1) such that the deformable membrane (42) faces the first substrate (1) and such that a gap (6) is provided between the deformable membrane (42) and the first substrate (1) which gap (6) contributes to the port,: wherein the first substrate (1) comprises a support portion (7) the cap (4) is attached to, a contact portion (8) for electrically connecting the pressure sensor to an external device, and one or more suspension elements (9) for suspending the support portion (7) from the contact portion (8). | 2. The sensor of claim 1,: wherein the first substrate (1) has a plane extension and wherein the support portion (7) encircles the contact portion (8) in the plane of the first substrate (1),: wherein the support portion (7) is separated from the contact portion (8) except for the one or more suspension elements (9) by one or more grooves (10) in the first substrate (1).
3. The sensor of claim 1 or claim 2,: wherein each suspension element (9) contains a ridge between the support portion (7) and the contact portion (8), and: wherein one or more of the suspension elements (9) includes at least one electrically conducting path for electrically connecting the support portion (7) to the contact portion (8).
4. The sensor of claim 2 or claim 3,: wherein the first substrate (1) has a front side (11) facing the deformable membrane (42), a backside (12) containing electrical contacts (16) for electrically connecting the pressure sensor to the external device, and vias (15) for electrically connecting the front side (11) of the first substrate (1) to its backside (12).
5. The sensor of claim 4,: wherein the electrical contacts (16) are arranged in the contact portion (8),: wherein the vias (15) are arranged in the support portion (7), and: wherein the vias (15) are electrically connected to the contact portion (7) through one or more of the suspension elements (9).
6. The sensor of any of the preceding claims,: wherein the cap (4) contains a second substrate (2) containing a bulk material (23) and layers (24) stacked on the bulk material (23),: wherein the cavity (41) is a recess exclusively arranged in one or more of the layers (24) of the second substrate (2),: wherein the processing circuit (241) is integrated in the second substrate (2), and: wherein the deformable membrane (42) is made from a third substrate (3) attached to the layers (24) of the second substrate (2).
7. The sensor of claim 6,: wherein the sensing means contains a first electrode formed by the deformable membrane (42) and a second electrode formed by one of the layers (24) of the second substrate (2),: wherein the first electrode and the second electrode are connected to the processing circuit (241).
8. The sensor of claim 7,: comprising spacer elements (5) between the first substrate (1) and the third or the second substrate (3,2) for building the gap (6), and: wherein at least some of the spacer elements (5) are used as electrical connections between the cap (4) and the first substrate (1). |
2871456 | Pressure sensor | 2 | Based on the following detailed description of an invention, generate the patent claims. There should be 7 claims in total. The first, independent claim is given and the remaining 6 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | The term "pressure sensor" as used herein designates any type of sensor measuring a parameter that is equal to or derived from the pressure of a fluid. In particular, the term designates relative (i.e. differential) as well as absolute pressure sensors, it also covers static as well as dynamic pressure sensors. Typical examples of applications of such sensors are e.g. in scientific instrumentation, meteorology, altitude measurement, sound recording, mobile or portable computers and phones etc.
Figure 1a ) shows a schematic sectional view of a pressure sensor in accordance with an embodiment of the present invention. The pressure sensor as shown is flipped with its solder balls 18 showing upwards while the pressure sensor will be mounted to a carrier with its solder balls sitting on the carrier.
The pressure sensor includes a first substrate 1 and a cap 4 for the first substrate 1.
The cap 4 preferably is made from a second substrate 2 and a third substrate 3. The second substrate 2 preferably is a semiconductor substrate, preferably a silicon substrate, and has a front side 21 and a backside 22. The second substrate 2 contains a bulk material 23 of, e.g. silicon and a stack of layers 24 on the bulk material 23. These layers 24 may be arranged for CMOS processing of the second substrate 2, and as such may also be denoted as CMOS layers or material layers. Specifically, the layers 24 can include for example a plurality of SiO2 layers, metal or polysilicon layers. The bulk material 23 may contain doped regions within the silicon such as indicated by the reference sign 241. These components can form active circuitry, such as amplifiers, A/D converters or other analog and/or digital signal processing units. A top layer 246 of the stack of layers 24 may be a dielectric layer of silicon oxide and/or silicon nitride protecting the structures below it. In the present example, it is assumed that a processing circuit collectively referred to as 241 is integrated on the front side 21 of the second substrate 2 by means of CMOS processing.
In the cap 4, a cavity 41 is formed by omitting or removing material from one or more of the layers 24, presently the top layer 246. The cavity 41 is closed by a deformable membrane 42. The membrane 42 is sufficiently thin such that it deforms depending on a pressure drop between a pressure at the top of the membrane 42 and below it. A metal layer 243 may be used as an electrode, and as such may be arranged at the bottom of the cavity 41.
The membrane 42 preferably is formed by a doped, conducting silicon layer, is arranged as a sealing lid over the cavity 41, and may be used as another electrode for which reason the deformable membrane 42 may contain electrically conducting material. Hence upon a change in pressure the membrane 42 deflects and as such a distance between the two electrodes changes which results in a change of the capacitance between the two electrodes.
In the present example, the deformable membrane 42 is built from a third substrate 3. The third substrate 3 as shown in Figure 1 may be the remainder of an SOI substrate, specifically its device layer after some manufacturing steps. The third substrate 3 not only may contribute to the deformable membrane 42. The third substrate 3 may contain contact windows 244 reaching through which may also reach into one or more of the layers 24.
Corresponding signals may be transmitted from the electrodes, i.e. the deformable membrane 42 and the metal layer 243 via electrical paths 242 to the processing circuit 241 where these signals are processed. Signals processed by the processing circuit 241 may be supplied to the first substrate 1.
The first substrate 1 may be a semiconductor substrate, e.g. a silicon substrate, or a glass substrate, for example, with a front side 11 and a back side 12. The semiconductor substrate 1 includes bulk material 13 such as silicon, and one or more layers 14, such as an oxide layer on the bulk material 13. The one or more layers 14 may further include for example a plurality of SiO2 layers, metal or polysilicon layers.
The first substrate 1 contains vias 15 reaching vertically through the first substrate 1. Those vias 15 provide for an electrical connection from the front side 11 of the substrate 1 to its backside 12. Those vias 15 are manufactured by etching or drilling holes into the first substrate 1 from its backside 12, by applying an oxide 151 to the hole, and by applying conducting material 152 to the oxide 151. At the back side 12 of the first substrate 1, the vias 15 are electrically connected to contact pads 16 residing on an oxide layer 17 applied to the bulk material 13, which contact pads 16 serve as support for solder balls 18 or other contact means for electrically connecting the pressure sensor to the outside world, i.e. to another device. Alternative to the vias 15 and the solder balls 18, there may be other ways of interconnecting the pressure sensor to the outside world, e.g. by means of wire bonds, bond pads or conducting structures that lead from the front side 11 of the first substrate 1 along its sides to the backside 12. The electrical connection to the outside world may also be implemented via one or more of a Land Grid Array, a Pin Grid Array, or a leadframe.
The assembly containing the second and the third substrate 2,3 is attached to the front side 11 of the first substrate 1. The attachment may include bonding or other fusion techniques. In the present example, spacer elements 5 are provided between the third substrate 3 and the first substrate 1. The spacer elements 5 may have different functions: On the one hand, the spacer elements 5 provide for a gap 6 between the deformable membrane 42 and the first substrate 1 which is required for supplying the pressure medium to the membrane 42. On the other hand, some of the spacer elements 5, but not necessarily all may be electrically conductive for connecting the contact windows 244 to the first substrate 1. Other or the same spacer elements 5 may provide mechanical stability for the stacking of substrates 1,3, and / or may provide mechanical protection to the inside of the pressure sensor, and specifically to the membrane 42. For this purpose, it may be preferred, that a spacer element 51 is arranged in from of a ring at the edges of the substrates 1,3 providing mechanical stability, protection as well as an electrical connection, while spacer elements 52 are rather pillar-like and provide electrical connections.
The signals provided by the processing circuit 241 hence may be transferred via one or more of the electrical paths 242 and via one or more of the contact windows 244 to one or more of the spacer elements 5. As shown in Figure 1, the spacer elements 52 end at the vias 15 of the first substrate 1 and are electrically connected thereto. Hence, the signals are conducted through the vias 15 to the contact pads 16 and the solder balls 18.
The first substrate 1 contains a support portion 7 and a contact portion 8. Suspension elements not shown in the present illustration are provided for suspending the support portion 7 from the contact portion 8. The support portion 7 preferably encircles the contact portion 8 in a plane of the first substrate 1.
The contact portion 8 is separated from the support portion 7 by one or more grooves 10. Owed to the manufacturing of the contact portion 8 and the support portion 7 from the common first substrate 1, both portions may include bulk material 13 from the first substrate 1.
The cap 4 preferably is exclusively attached to the support portion 7 of the first substrate 1 via the spacer elements 5. On the other hand, it is preferred that it is solely the contact portion that provides a mechanical and electrical contact to the outside world. Hence, the portion of the pressure sensor via which mechanical stress is induced, i.e. the contact portion 8 is mechanically decoupled from the rest of the pressure sensor and specifically from the deformable membrane 42 by way of the suspension elements.
A port for conducting a medium to the deformable membrane 42 in the present example encompasses the the grooves 10 and the gap 6, or at least parts of.
The overall height of the pressure sensor in the present example is about 400 µm.
Figure 1b ) illustrates a representative horizontal cut of a pressure sensor, e.g. according to line A-A' in Figure 1a ) not necessarily matching all elements as provided in Figure 1a ). A mechanical support 32 holds the third substrate 3. In the third substrate 3, a plurality of contact windows 244 are provided which contain electrically conducting material 2441 in their interior. The third substrate 3 also builds the deformable membrane 42. Then, the horizontal cut switches to a different plane, i.e. the plane of the electrode 243. This electrode 243 is surrounded by the cavity 41.
Figure 1c ) illustrates a bottom view onto the first substrate 1 of the pressure sensor. The first substrate 1 contains a support portion 7 and a contact portion 8 wherein the support portion 7 is suspended from the contact portion 8 by means of a suspension element 9, which is a representation of a mechanical link between the two portions 7 and 8. A groove 10 is arranged vertically through the first substrate 1. Vias 15 are arranged in the support portion 7, while the solder balls 18 are arranged in the contact portion 8. The contact portion 8 is electrically connected to the support portion 7 by means of electrically conducting structures such as the contact pads 16 which electrically conducting structures may in generally be denoted as redistribution layer.
Figure 2 shows in its diagrams a) to d) schematic cross-sections of a pressure sensor according an embodiment of the present invention during manufacturing thereby illustrating the individual processing steps. In Figure 2a ) a preprocessed second substrate 2 is shown with a front side 21 and a back side 22 including a bulk material 23 and layers 24 stacked on the bulk material 23, which layers 24 are only schematically illustrated and may contain oxide layers, e.g. SiO2, metal layers, and / or polysilicon layers such as layer 243 serving as electrode, and a top layer 246 serving as passivation layer. A processing circuit 241 is integrated into the second substrate 2, e.g. by doping the bulk material 23 and / or by structuring the layer stack 24. In addition, a cavity 41 is etched into the layers 24, and preferably into the top layer 246.
In a next step, the deformable membrane 42 is built on the preprocessed substrate 2. For this purpose, a third substrate 3 in form of an SOI substrate is attached to the layers 24 of the second substrate 2 at its front side 21 e.g. by fusion bonding. The SOI substrate may contain bulk material, an insulation layer in form of a BOX layer, and a silicon layer as device layer. As a result, the cavity 41 is closed. In a further step not explicitly shown in the Figures, the bulk material and the insulation layer of the SOI substrate are removed such that the silicon layer remains as third substrate 3 covering the cavity 41, which silicon layer is thin enough to deflect in response to pressure applied.
In a next step, contact windows 244 are etched through the third substrate 3 into the layers 24 of the second substrate 2. The contact windows 244 are metalized and spacer elements 51 and 52 are applied to the third substrate 3.
In a next step illustrated in Figure 2b ), a preprocessed first substrate 1 is attached to the assembly of the second and the third substrate 2, 3. The first substrate 1 is preprocessed, for example, according to the diagrams of Figure 3.
In the diagram of Figure 3a ) a first substrate 1 is provided, e.g. a semiconductor substrate such as a silicon substrate. At its top side, one or more layers 14 are arranged, such as CMOS layers, or simply an isolation layer such as a silicon-oxide layer. In an additional step shown in Figure 3b ), spacer elements 51 and 52 are arranged at the front side 11 of the first substrate 1. In the step shown in Figure 3c ), trenches 101 are etched into the bulk material 13 of the first substrate thereby penetrating the layers 14, e.g. by deep reactive ion etching.
The first substrate 1 preprocessed according to Figure 3c ) then is applied to the assembly of the preprocessed second and third substrate 2, 3 according to Figure 2a ) thereby resulting in an assembly according to Figure 2b ).
In a next step as illustrated in Figure 2c ), the first substrate 1 is thinned from its backside 11 to a reduced thickness in the range of e.g. 100 to 200 microns. This process can be performed using grinding, etching or milling.
In the step illustrated in Figure 2d ), the first substrate 1 is continued to be processed: Vias 15 are manufactured through the first substrate 1. Preferably in a step following the manufacturing of the vias 15, the trenches 101 in the first substrate 1 are opened from the backside 12 of the first substrate 1, e.g. by way of etching such that one or more grooves 10 are now provided reaching through the first substrate 1. In a last step, solder balls 18 or other contact structures may be attached to the backside 12 of the first substrate 1. The result is shown in Figure 1.
By having manufactured the one or more grooves 10, the first substrate 1 is separated into a support portion 7 to which the cap 4 is attached, and a contact portion 8 via which the pressure sensor is electrically connected to another device.
It should further be noted that in any removal of material during manufacturing, the corresponding structures may be created using a chemical (wet) etching process, plasma etching process, laser cutting, mechanical milling or a combination of any of these processes, where suitable. | 9. A method for manufacturing a pressure sensor, comprising the steps of: providing a first substrate (1),: providing a second substrate (2),: providing a third substrate (3),: manufacturing a cavity (41)) in the second substrate (2),: mounting the third substrate (3) to the second substrate (2) thereby covering the cavity (41) in the second substrate (2) to form a deformable membrane (42) for sensing a pressure applied to the deformable membrane (42),: mounting the assembly of the second substrate (2) and the third substrate (3) to a support portion (7) of the first substrate (1) with the deformable membrane (42) facing the first substrate (1) and providing a gap (6) between the deformable membrane (42) and the first substrate (1), and: manufacturing grooves (10) into the first substrate (1) around a contact portion (8) for electrically connecting the pressure sensor to an external device, thereby making the support portion (7) suspend from the contact portion (8) by means of suspension elements (9). | 10. The method of claim 9,: wherein manufacturing the cavity (41) in the second substrate (2) includes manufacturing the cavity (41) in one or more layers (24) stacked on a bulk material (23) of the second substrate (2), and: wherein mounting the third substrate (3) to the second substrate (2) to form the deformable membrane (42) includes attaching a silicon-on-insulator substrate to a top layer of the second substrate (2), removing a bulk material and an insulating layer of the silicon-on-insulator substrate thereby leaving a silicon layer as deformable membrane (42) spanning the cavity (41) in the second substrate (2).
11. The method of claim 9 or claim 10, wherein manufacturing the grooves (10) into the first substrate (1) includes manufacturing trenches (101) reaching at least partly into the first substrate (1) prior to attaching the assembly to the first substrate (1), and: in particular wherein the trenches (101) are manufactured by etching.
12. The method of claim 11,: wherein the trenches (101) that reach partially into the first substrate (1) are manufactured from its front side (11) prior to attaching the assembly to the first substrate (1), and: wherein the trenches (101) in the first substrate (1) are laid open from its backside (12) after having attached the assembly of the second substrate (2) and the third substrate (3) to the first substrate (1).
13. The method of any of the preceding claims 9 to 12,: wherein electrically conducting vias (15) are built through the first substrate (1) for electrically connecting the processing circuit (241) to electrical contacts (16) arranged on a backside (12) of the first substrate (1) opposite a front side (11) facing the deformable membrane (42), and: in particular wherein the vias (15) are built after having mounted the assembly of the second substrate (2) and the third substrate (3) to the first substrate (1).
14. The method of any one of the preceding claims 9 to 13,: wherein mounting the third substrate (3) to the second substrate (2) includes in a portion of the third substrate (3) outside the deformable membrane - etching through the third substrate (3) for manufacturing one or more contact windows (244) in the second substrate (2), and - metalizing the one or more contact windows (222).
15. The method of any one of the preceding claims 9 to 14,: wherein the gap (6) between the first substrate (1) and the assembly of the second and third substrate (2,3) is manufactured by applying spacer elements (5) between the first substrate (1) and the assembly of the second and third substrate (2,3). |
2871152 | Sensor device | 1 | Based on the following detailed description of an invention, generate the patent claims. There should be 9 claims in total. The first, independent claim is given and the remaining 8 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | Figure 1 a) shows a schematic sectional view of a sensor device in accordance with an embodiment of the present invention. The sensor device includes a sensitive element 1, which is integrated in a support 2. In this embodiment, the support 2 is a semiconductor substrate, e.g. a silicon substrate, and it may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit, through silicon vias and solder balls. The gas to be sensed can enter the sensitive element 1 via the access opening 4 which is located in a surface 3 of the support 2. Parts of the surface 3 are covered by a layer of adhesive material 5. A venting medium 6 extends over the entire surface 3 of the support 2 and the access opening 4 and is attached to the support 2 by the layer of adhesive material 5.
Figure 1 b) shows another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensitive element 1 is located in a cavity 7 in the support 2. The cavity 7 opens out into the surface 3 and thereby defines the access opening 4.
Figure 1 c) illustrates another embodiment of a sensor device in accordance with the present invention. In this embodiment, the support 2 of the sensor device contains a spacer material 8 on top of a silicon substrate 13, for example.
Figure 1 d) shows another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensor device comprises a top element 9 on a part of the venting medium 6. The top element 9 may serve as protection for the venting medium. Also, it may contain labels and/or alignment marks. The top element 9 may be made from silicon, glass, polymer or any other material that serves one or several of the aforementioned purposes.
Figure 2 a) illustrates another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensor device comprises a die 10 with the sensing element 1. The die 10 may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit. The die 10 is partly covered by a mold 11 and a lead frame 12 serves for outside contacting. A cavity 7 is formed by the die 10 and the mold 11. The cavity 7 opens out into the surface 3 and thereby defines the access opening 4. A venting medium 6 extends over the entire surface 3 of the support 2 and the access opening 4 and is attached to the support 2 by the layer of adhesive material 5.
Figure 2 b) illustrates another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensor device comprises a silicon substrate 13 with the sensitive element 1. The silicon substrate 13 may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit, through silicon vias and solder balls. The silicon substrate 13 is partly covered by a silicon cap 14. A cavity 7 is formed by the silicon substrate 13 and the silicon cap 14. The cavity 7 opens out into the surface 3 and thereby defines the access opening 4. A venting medium 6 extends over the entire surface 3 of the support 2 and the access opening 4 and is attached to the support 2 by the layer of adhesive material 5.
Figure 2c ) illustrates another embodiment of the sensor device in accordance with the present invention. The support 2 contains a substrate, and in particular a silicon substrate 13. A sensitive element 1 is arranged on a suspended membrane portion of the silicon substrate 13 which suspended membrane, for example, is prepared by etching substrate material from a backside of the silicon substrate 13. Hence, a cavity 7 is generated which opens out to the backside of the silicon substrate 13. As a result, the support 2 provides an access opening 4 at its backside. For this reason, the relevant surface 3 of the support 2 is at its backside such that the venting medium 6 is attached to the surface 3 at the backside of the support 2 by means of the layer of adhesive material 5.
Figure 3 illustrates in its diagrams a) to d) steps of manufacturing a sensor device in accordance with an example of the invention.
In Figure 3 a) a sensor support assembly 22 containing an array of sensitive elements 1 for manufacturing a plurality of sensor devices is provided. In this embodiment, the sensor support assembly 22 comprises a plurality of dies 10 which are partly covered by a mold 11. The dies 10 may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit. A lead frame 12 serves for outside contacting. The sensor support assembly 22 has a surface 3 with access openings 4 to the sensitive elements 1.
In Figure 3 b) a layer of adhesive material 5 is applied to parts of the surface 3 of the sensor support assembly 22 which surface 3 contains the access openings 4.
In Figure 3 c) a venting medium 6 is arranged over the entire surface 3 of the sensor support assembly 22 and the access openings 4. The venting medium 6 is attached to the sensor support assembly 22 by the layer of adhesive material 5. In this embodiment, the venting medium is not pre-structured and especially not pre-patterned to match the patterning of the surface of the sensor support assembly. The venting medium is a complete, unstructured venting layer that covers the plurality of access openings and the related surface.
For this step it may be helpful that the venting medium is attached during the transfer to a transfer substrate. This may facilitate the handling of the venting medium and protect it against damage. Here, in this embodiment, the transfer layer is removed after the transfer.
In Figure 3 d) the sensor support assembly 22 is separated 23 into individual sensor devices or groups of sensor devices. Sensor device singulation may e.g. be implemented by dicing or laser cutting or any other singulation technique. In this embodiment, a top element 9 was placed on the venting medium before sensor device singulation 23. This may serve as protection for the venting medium, especially during the singulation and to ease the singulation process itself. The top element 9 may also contain separation marks and/or alignment marks facilitating the separation process. It may also contain labels and/or identification marks which may provide information on the sensor device, e.g. a device number, or sensor device type, e.g. a product number or type.
Figure 4 illustrates in its diagrams a) to d) steps of manufacturing a sensor device in accordance with another example of the invention.
In Figure 4 a) a sensor support assembly 22 containing an array of sensitive elements 1 for manufacturing a plurality of sensor devices is provided. In this embodiment, the sensor support assembly 22 comprises a semiconductor substrate 13 which is partly covered by a silicon cap 14. Instead of the silicon cap 14, a mold structure may be provided, too. The sensor support assembly 22 has a surface 3 with access openings 4 to the sensitive elements 1.
In Figure 3 b) a layer of adhesive material 5 is applied to parts of the surface 3 of the sensor support assembly 22 which surface 3 contains the access openings 4.
In Figure 3 c) a venting medium 6 is arranged over the entire surface 3 of the sensor support assembly 22 and the access openings 4. The venting medium 6 is attached to the sensor support assembly 22 by the layer of adhesive material 5. In this embodiment, the venting medium 6 is not pre-structured and especially not pre-patterned to match the patterning of the surface of the sensor support assembly. The venting medium is a complete, unstructured venting layer that covers the plurality of access openings and the related surface.
For this step it may be helpful that the venting medium is attached during to a transfer substrate. This may facilitate the handling of the venting medium and protect it against damage. The transfer substrate can remain entirely or in parts on the membrane.
In Figure 3 d) the sensor support assembly 22 is separated 23 into individual sensor devices or groups of sensor devices. Sensor device singulation may e.g. be implemented by dicing or laser cutting or any other singulation technique.
In this embodiment a top element 9 was placed on the venting medium before sensor device singulation 23. This may serve as protection for the venting medium, especially during the singulation. The top element 9 may also contain separation marks and/or alignment marks facilitating the separation process. It may also contain labels and/or identification marks which may provide information on the sensor device, e.g. a device number, or sensor device type, e.g. a product number or type.
It should further be noted that in any removal of material during manufacturing, the corresponding structures may be created using a chemical (wet) etching process, plasma etching process, laser cutting, mechanical milling or a combination of any of these processes, where suitable. | 1. A sensor device, comprising: - a sensitive element (1), - a support (2) for the sensitive element (1), the support (2) having a surface (3) with an access opening (4) to the sensitive element (1), - a layer of adhesive material (5) covering at least parts of the surface (3), - a venting medium (6) extending over the entire surface (3) of the support (2) and the access opening (4) and being attached to the support (2) by the layer of adhesive material (5). | 2. The sensor device of claim 1,: wherein the sensitive element (1) is sensitive to one or more of: - pressure - gas - humidity - gas flow - differential pressure.
3. The sensor device of claim 1 or 2,: wherein the sensitive element (1) is located in a cavity (7) in the support (2),: and wherein the cavity (7) opens out into the surface (3) and thereby defines the access opening (4).
4. The sensor device of any one of the preceding claims,: wherein the support (2) comprises one or more of a substrate (13) and a carrier, and a spacer material (8) between the layer of adhesive material (5) and the substrate (13) or the carrier respectively.
5. The sensor device of any one of the preceding claims,: comprising a top element (9) on a part of the venting medium (6) and in particular wherein the top element (9) comprises one or more of: - an element for protecting the venting medium - a label - an identification mark - an alignment mark.
6. The sensor device of claim 5,: wherein the top element (9) includes one or more of: - polymer - filled polymer - mold compound - silicon - glass - metal.
7. The sensor device of any one of the preceding claims,: wherein the support (2) contains one or more of: - a die (10) - a mold (11) - a lead frame (12) - a silicon substrate (13) - a silicon cap (14) - a semiconductor substrate - a ceramic substrate - a glass substrate - a printed circuit board - a ball grid array - a land grid array - through-silicion vias - wire-bonds - T-contacts - a silicon interposer - a heater structure - a suspended membrane - an integrated processing circuit.
8. The sensor device of any one of the preceding claims,: wherein the venting medium (6) contains one or more of: - a polymer - a fluoropolymer - PTFE - an acrylic copolymer - a polyethersulfone polymer - glass fiber - porous organic material - porous inorganic material.
9. The sensor device of any one of the preceding claims,: wherein the venting medium (6) extends over the entire surface (3) and the access opening (4) and wherein another venting medium is attached to another surface of the support (2) opposite the surface (3) containing the access opening (4). |
2871152 | Sensor device | 2 | Based on the following detailed description of an invention, generate the patent claims. There should be 6 claims in total. The first, independent claim is given and the remaining 5 dependent claims need to be written. Do not repeat the first claim. The claims should be clear, precise, consistent and consice and should be grounded in the information in the detailed description. | Figure 1 a) shows a schematic sectional view of a sensor device in accordance with an embodiment of the present invention. The sensor device includes a sensitive element 1, which is integrated in a support 2. In this embodiment, the support 2 is a semiconductor substrate, e.g. a silicon substrate, and it may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit, through silicon vias and solder balls. The gas to be sensed can enter the sensitive element 1 via the access opening 4 which is located in a surface 3 of the support 2. Parts of the surface 3 are covered by a layer of adhesive material 5. A venting medium 6 extends over the entire surface 3 of the support 2 and the access opening 4 and is attached to the support 2 by the layer of adhesive material 5.
Figure 1 b) shows another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensitive element 1 is located in a cavity 7 in the support 2. The cavity 7 opens out into the surface 3 and thereby defines the access opening 4.
Figure 1 c) illustrates another embodiment of a sensor device in accordance with the present invention. In this embodiment, the support 2 of the sensor device contains a spacer material 8 on top of a silicon substrate 13, for example.
Figure 1 d) shows another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensor device comprises a top element 9 on a part of the venting medium 6. The top element 9 may serve as protection for the venting medium. Also, it may contain labels and/or alignment marks. The top element 9 may be made from silicon, glass, polymer or any other material that serves one or several of the aforementioned purposes.
Figure 2 a) illustrates another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensor device comprises a die 10 with the sensing element 1. The die 10 may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit. The die 10 is partly covered by a mold 11 and a lead frame 12 serves for outside contacting. A cavity 7 is formed by the die 10 and the mold 11. The cavity 7 opens out into the surface 3 and thereby defines the access opening 4. A venting medium 6 extends over the entire surface 3 of the support 2 and the access opening 4 and is attached to the support 2 by the layer of adhesive material 5.
Figure 2 b) illustrates another embodiment of a sensor device in accordance with the present invention. In this embodiment, the sensor device comprises a silicon substrate 13 with the sensitive element 1. The silicon substrate 13 may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit, through silicon vias and solder balls. The silicon substrate 13 is partly covered by a silicon cap 14. A cavity 7 is formed by the silicon substrate 13 and the silicon cap 14. The cavity 7 opens out into the surface 3 and thereby defines the access opening 4. A venting medium 6 extends over the entire surface 3 of the support 2 and the access opening 4 and is attached to the support 2 by the layer of adhesive material 5.
Figure 2c ) illustrates another embodiment of the sensor device in accordance with the present invention. The support 2 contains a substrate, and in particular a silicon substrate 13. A sensitive element 1 is arranged on a suspended membrane portion of the silicon substrate 13 which suspended membrane, for example, is prepared by etching substrate material from a backside of the silicon substrate 13. Hence, a cavity 7 is generated which opens out to the backside of the silicon substrate 13. As a result, the support 2 provides an access opening 4 at its backside. For this reason, the relevant surface 3 of the support 2 is at its backside such that the venting medium 6 is attached to the surface 3 at the backside of the support 2 by means of the layer of adhesive material 5.
Figure 3 illustrates in its diagrams a) to d) steps of manufacturing a sensor device in accordance with an example of the invention.
In Figure 3 a) a sensor support assembly 22 containing an array of sensitive elements 1 for manufacturing a plurality of sensor devices is provided. In this embodiment, the sensor support assembly 22 comprises a plurality of dies 10 which are partly covered by a mold 11. The dies 10 may include additional features, such as a heater structure, a suspended membrane, an integrated processing circuit. A lead frame 12 serves for outside contacting. The sensor support assembly 22 has a surface 3 with access openings 4 to the sensitive elements 1.
In Figure 3 b) a layer of adhesive material 5 is applied to parts of the surface 3 of the sensor support assembly 22 which surface 3 contains the access openings 4.
In Figure 3 c) a venting medium 6 is arranged over the entire surface 3 of the sensor support assembly 22 and the access openings 4. The venting medium 6 is attached to the sensor support assembly 22 by the layer of adhesive material 5. In this embodiment, the venting medium is not pre-structured and especially not pre-patterned to match the patterning of the surface of the sensor support assembly. The venting medium is a complete, unstructured venting layer that covers the plurality of access openings and the related surface.
For this step it may be helpful that the venting medium is attached during the transfer to a transfer substrate. This may facilitate the handling of the venting medium and protect it against damage. Here, in this embodiment, the transfer layer is removed after the transfer.
In Figure 3 d) the sensor support assembly 22 is separated 23 into individual sensor devices or groups of sensor devices. Sensor device singulation may e.g. be implemented by dicing or laser cutting or any other singulation technique. In this embodiment, a top element 9 was placed on the venting medium before sensor device singulation 23. This may serve as protection for the venting medium, especially during the singulation and to ease the singulation process itself. The top element 9 may also contain separation marks and/or alignment marks facilitating the separation process. It may also contain labels and/or identification marks which may provide information on the sensor device, e.g. a device number, or sensor device type, e.g. a product number or type.
Figure 4 illustrates in its diagrams a) to d) steps of manufacturing a sensor device in accordance with another example of the invention.
In Figure 4 a) a sensor support assembly 22 containing an array of sensitive elements 1 for manufacturing a plurality of sensor devices is provided. In this embodiment, the sensor support assembly 22 comprises a semiconductor substrate 13 which is partly covered by a silicon cap 14. Instead of the silicon cap 14, a mold structure may be provided, too. The sensor support assembly 22 has a surface 3 with access openings 4 to the sensitive elements 1.
In Figure 3 b) a layer of adhesive material 5 is applied to parts of the surface 3 of the sensor support assembly 22 which surface 3 contains the access openings 4.
In Figure 3 c) a venting medium 6 is arranged over the entire surface 3 of the sensor support assembly 22 and the access openings 4. The venting medium 6 is attached to the sensor support assembly 22 by the layer of adhesive material 5. In this embodiment, the venting medium 6 is not pre-structured and especially not pre-patterned to match the patterning of the surface of the sensor support assembly. The venting medium is a complete, unstructured venting layer that covers the plurality of access openings and the related surface.
For this step it may be helpful that the venting medium is attached during to a transfer substrate. This may facilitate the handling of the venting medium and protect it against damage. The transfer substrate can remain entirely or in parts on the membrane.
In Figure 3 d) the sensor support assembly 22 is separated 23 into individual sensor devices or groups of sensor devices. Sensor device singulation may e.g. be implemented by dicing or laser cutting or any other singulation technique.
In this embodiment a top element 9 was placed on the venting medium before sensor device singulation 23. This may serve as protection for the venting medium, especially during the singulation. The top element 9 may also contain separation marks and/or alignment marks facilitating the separation process. It may also contain labels and/or identification marks which may provide information on the sensor device, e.g. a device number, or sensor device type, e.g. a product number or type.
It should further be noted that in any removal of material during manufacturing, the corresponding structures may be created using a chemical (wet) etching process, plasma etching process, laser cutting, mechanical milling or a combination of any of these processes, where suitable. | 10. A method for manufacturing a sensor device, comprising: - providing a sensor support assembly (22) containing an array of sensitive elements (1) for manufacturing a plurality of sensor devices, the sensor support assembly (22) having a surface (3) with access openings (4) to the sensitive elements (1), - depositing a layer of adhesive material (5) on at least parts of the surface (3) of the sensor support assembly (22) which surface (3) contains the access openings (4), - arranging a venting medium (6) over the entire surface (3) of the sensor support assembly (22) and the access openings (4), wherein the venting medium (6) is attached to the sensor support assembly (22) by the layer of adhesive material (5) - separating (23) the sensor support assembly (22) into individual sensor devices or groups of sensor devices. | 11. The method of claim 10,: wherein the venting medium (6) is not pre-structured.
12. The method of claim 10 or 11,: wherein prior to separating the sensor support assembly (22), top elements (9) are deposited on parts of the venting medium (6) and in particular wherein the top elements (9) include one or more of: - a protection for the venting medium (6) - a means to ease singulation - a label - an identification mark - a separation mark - an alignment mark.
13. The method of any one of claims 10 to 12,: wherein the venting medium (6) is fixed on a transfer support, which is entirely or partly removed after attachment of the venting medium (6) to the sensor support assembly (22), before or after separating the sensor support assembly (22) into individual sensor devices or groups of sensor devices.
14. The method of any one of claims 10 to 13,: wherein the sensor support assembly (22) contains one or a more of: - a die (10) - a mold (11) - a lead frame (12) - a silicon substrate (13) - a silicon cap (14) - a semiconductor substrate - a ceramic substrate - a glass substrate - a temporary carrier - a printed circuit board - a ball grid array - a land grid array - wire-bonds - through-silicion vias - T-contacts - a silicon interposer - a heater structure - a suspended membrane - an integrated processing circuit.
15. The method of any one of claims 10 to 14,: wherein the layer of adhesive material (5) is deposited on at least parts of the surface (3) of the sensor support assembly (22) by one or more of: - printing - dispensing - stamping - spin coating - lamination - a structuring process - photo-lithography. |
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This is the first version of the Subclaim Generator data set. It contains detailed descriptions, independent claims, and dependent claims for engineering patents from 2015.
The description length has been limited to 25k characters. The number of claim sets has been limited to 5.
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Claims sets are detected by the presence of the word "claim": if a claim contains the word "claim", we assume it is dependent on the last independent claim.
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