Camera package, method for manufacturing camera package, and electronic device

The present disclosure relates to a camera package, a method for manufacturing a camera package, and an electronic device with which it is possible to reduce manufacturing cost for lens formation.The camera package according to the present disclosure includes: a solid-state imaging element; and a lens formed above a transparent substrate that protects the solid-state imaging element. A lens formation region in which the lens is formed above the transparent substrate and a lens free region around the lens formation region differ in contact angle. The present disclosure can be applied to, for example, a camera package in which a lens is disposed above a solid-state imaging element, or the like.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International Patent Application No. PCT/JP2020/006166 filed on Feb. 18, 2020, which claims priority benefit of Japanese Patent Application No. JP 2019-030169 filed in the Japan Patent Office on Feb. 22, 2019. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a camera package, a method for manufacturing a camera package, and an electronic device, and more particularly to a camera package, a method for manufacturing a camera package, and an electronic device with which it is possible to reduce manufacturing cost for lens formation.

BACKGROUND ART

As a method for forming a lens on a substrate, an imprinting technology of pressing a mold against a resin dropped on the substrate to transfer a mold shape is known. In order to form a defect-free lens with an excellent yield, it is common to use a method for forming a lens by dropping an excessive amount of resin with respect to the volume of the lens so that the resin protrudes from the mold. The reason to drop an excessive amount of resin is to form a bulky lens with a complicated shape, because the resin spreads by its own weight when being dropped onto the substrate.

For example, Patent Document 1 suggests a technology of providing an overflow section which traps an excessive resin on a mold so that the excessive resin does not flow into an unnecessary region.

CITATION LIST

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

Dropping resin more than necessary leads to an increase in manufacturing cost. In addition, if the mold is provided with an overflow section, the size of the mold itself is increased, and thus, in a case where multiple lenses are simultaneously molded on the substrate, the distance between the adjacent lenses cannot be reduced, resulting in generating a loss in the substrate. This leads to an increase in manufacturing cost.

The present disclosure is accomplished in view of such a situation, and an object of the present disclosure is to reduce manufacturing cost required for lens formation.

Solutions to Problems

A camera package according to a first aspect of the present technology includes: a solid-state imaging element; and a lens formed above a transparent substrate that protects the solid-state imaging element, in which a lens formation region in which the lens is formed above the transparent substrate and a lens free region around the lens formation region differ in contact angle.

A method for manufacturing a camera package according to a second aspect of the present technology includes: performing processing such that a lens formation region above a transparent substrate that protects a solid-state imaging element and a lens free region around the lens formation region differ in contact angle; dropping a lens material into the lens formation region above the transparent substrate; and pressing a mold to form a lens.

In the second aspect of the present technology, processing is performed such that a lens formation region above a transparent substrate that protects a solid-state imaging element and a lens free region around the lens formation region differ in contact angle, a lens material is dropped into the lens formation region above the transparent substrate, and a mold is pressed to form a lens.

An electronic device according to a third aspect of the present technology includes: a camera package including a solid-state imaging element, and a lens formed above a transparent substrate that protects the solid-state imaging element, in which a lens formation region in which the lens is formed above the transparent substrate and a lens free region around the lens formation region differ in contact angle; and a lens module including one or more lens-equipped substrates disposed above the camera package.

In the first and third aspects of the present technology, a solid-state imaging element and a lens formed above a transparent substrate that protects the solid-state imaging element are provided, and a lens formation region in which the lens is formed above the transparent substrate and a lens free region around the lens formation region differ in contact angle.

The camera package and electronic device may be an independent device or a module incorporated in another device.

MODE FOR CARRYING OUT THE INVENTION

Modes (hereinafter referred to as embodiments) for carrying out the present disclosure will be described below. Note that the description will be given in the following order.1. Schematic structure of camera package2. System configuration of camera package3. Method for forming lens resin part4. Timing of formation of lens resin part5. Modification6. First formation method for forming high contact angle film7. Second formation method for forming high contact angle film8. Third formation method for forming high contact angle film9. Fourth formation method for forming high contact angle film10. Formation of mold11. Schematic structure of camera package without having high contact angle film12. Operation and effect of mold13. Modification of mold14. Another embodiment of mold15. Detailed structure of solid-state imaging element16. Method for manufacturing camera package17. Configuration example of camera module18. Direct bonding between lens-equipped substrates19. Method for manufacturing lens-equipped substrate20. Example of application to electronic device21. Example of application to in-vivo information acquisition system22. Example of application to endoscopic surgical system23. Example of application to mobile object
<1. Schematic Structure of Camera Package>

FIG.1shows a schematic structure of a camera package as a semiconductor device to which the present disclosure is applied.

The camera package1shown inFIG.1converts light or electromagnetic wave entering the device in the direction of an arrow in the figure into an electric signal. Hereinafter, the present disclosure will give description, taking a device that uses light as a target to be converted into an electric signal as an example for the sake of convenience.

The camera package1includes at least a solid-state imaging element13having a laminated structure of a first structure11and a second structure12, an external terminal14, a protective substrate18formed above the first structure11, a lens resin part19formed on the protective substrate18, and a high contact angle film20formed around the lens resin part19. Note that, in the following, for convenience, the first structure11is referred to as an upper structure11, and the second structure12is referred to as a lower structure12with the light incidence surface side where light enters the device being defined as an upper side, and the other surface side of the device facing the light incidence surface being defined as a lower side inFIG.1.

The camera package1is formed such that a semiconductor substrate (wafer) constituting a part of the upper structure11, a semiconductor substrate (wafer) constituting a part of the lower structure12, and the protective substrate18are bonded at wafer level, and then, the resultant is diced into individual camera packages1.

In the upper structure11before the dicing process, pixels for converting incident light into an electric signal are formed on the semiconductor substrate (wafer). Each pixel includes, for example, a photodiode (PD) for photoelectric conversion and a plurality of pixel transistors that controls a photoelectric conversion operation and an operation of reading a photoelectrically converted electric signal. The pixel transistors are preferably MOS transistors, for example. The upper structure11included in the diced camera package1may be referred to as an upper chip, an image sensor substrate, or an image sensor chip.

For example, an R (red), G (green), or B (blue) color filter15and an on-chip lens16are formed on the upper surface of the upper structure11. The protective substrate18for protecting the structure of the camera package1, particularly the on-chip lens16and the color filter15, is provided above the on-chip lens16. The protective substrate18is a transparent substrate such as a glass substrate, for example. When the hardness of the protective substrate18is higher than the hardness of the on-chip lens16, the effect of protecting the on-chip lens16is increased.

A lens resin part19formed by molding a resin material serving as a lens material into a predetermined shape by imprinting is provided on the upper surface of the protective substrate18. The lens resin part19functions as a lens that refracts incident light in a predetermined direction so that the incident light enters a predetermined pixel of the upper structure11. Further, a high contact angle film20is formed around the lens resin part19on the upper surface of the protective substrate18. The high contact angle film20refers to a film in which, when the resin material that is the lens material is dropped in a step of forming the lens resin part19, the contact angle of the resin material is greater than the contact angle of the protective substrate18.

The lower structure12before the dicing process has a configuration in which a semiconductor circuit including a transistor and wiring is formed on a semiconductor substrate (wafer). The lower structure12included in the diced camera package1may be referred to as a lower chip, a signal processing substrate, or a signal processing chip. The lower structure12is provided with a plurality of external terminals14for electrical connection to wirings (not shown) outside the device. The external terminals14are, for example, solder balls.

The camera package1has a cavityless structure in which the protective substrate18is fixed above the upper structure11or above the on-chip lens16via a sealing resin17disposed on the on-chip lens16. The sealing resin17has a hardness lower than the hardness of the protective substrate18, and therefore, has a function of preventing transmission of a stress, which is applied to the protective substrate18from the outside of the camera package1, to the inside of the device, as compared with a case where the sealing resin is not provided.

Note that the camera package1may have a structure different from the cavityless structure. Specifically, the camera package1may have a cavity structure in which a columnar or wall-like structure is formed on the upper surface of the upper structure11, and the protective substrate18is fixed to the abovementioned columnar or wall-like structure so as to be supported above the on-chip lens16with a cavity.

<2. System Configuration of Camera Package>

FIG.2is a block diagram showing a system configuration example of the camera package1.

The camera package1shown inFIG.2includes a pixel array unit24in which multiple pixels31each having a photoelectric conversion unit (PD) are arrayed in a row direction and a column direction.

The pixel array unit24is provided with row drive signal lines32for driving the pixels31for each row, and vertical signal lines (column read lines)33for reading a signal generated as a result of photoelectric conversion from a plurality of pixels31driven for each row. As shown inFIG.2, multiple pixels31arrayed in the row direction are connected to one row drive signal line32. Multiple pixels31arrayed in the column direction are connected to one vertical signal line33.

The camera package1further includes a row drive unit22and a column signal processor25.

The row drive unit22includes, for example, a row address controller, in other words, a row decoder unit, that determines a row position for driving pixels, and a row drive circuit unit that generates a signal for driving the pixel31.

The column signal processor25includes, for example, a load circuit unit which is connected to the vertical signal lines33and which constitutes a source follower circuit with the pixels31. Further, the column signal processor25may include an amplifier circuit unit that amplifies signals read from the pixels31via the vertical signal lines33. In addition, the column signal processor25may further include a noise processor for removing a noise level of the system from the signals read from the pixels31as a result of photoelectric conversion.

The column signal processor25includes an analog-to-digital converter (ADC) for converting the signal read from the pixel31or the analog signal that has been subjected to the noise processing described above into a digital signal. The ADC includes a comparator unit for comparing the analog signal to be converted with a reference sweep signal that is to be compared with the analog signal, and a counter unit for counting the time until the comparison result in the comparator unit is inverted. The column signal processor25may further include a horizontal scanning circuit unit which performs control such that the read column is scanned.

The camera package1further includes a timing controller23. The timing controller23supplies a signal for controlling a timing to the row drive unit22and the column signal processor25on the basis of a reference clock signal and a timing control signal input to the device. Hereinafter, in the present disclosure, all or a part of the row drive unit22, the column signal processor25, and the timing controller23may be simply referred to as a pixel peripheral circuit unit, a peripheral circuit unit, or a control circuit unit.

The camera package1further includes an image signal processor26. The image signal processor26is a circuit that performs various kinds of signal processing on the data obtained as a result of photoelectric conversion, in other words, the data obtained as a result of an imaging operation in the camera package1. The image signal processor26includes, for example, an image signal processing circuit unit and a data holding unit. The image signal processor26may further include a processor unit.

Examples of signal processing executed by the image signal processor26include tone curve correction processing for increasing the tone level in a case where the AD-converted imaging data indicates data obtained by capturing a dark subject, and reducing the tone level in a case where the AD-converted imaging data indicates data obtained by capturing a bright subject. In this case, it is desirable to store characteristic data of a tone curve in the data holding unit of the image signal processor26in advance in order to determine what kind of tone curve is used to correct the tone of the imaging data.

The camera package1further includes an input unit21A. The input unit21A inputs, for example, the abovementioned reference clock signal, timing control signal such as a vertical synchronization signal and a horizontal synchronization signal, characteristic data to be stored in the data holding unit of the image signal processor26, or the like to the camera package1from outside the device. The input unit21A includes an input terminal41which is an external terminal14for inputting data to the camera package1, and an input circuit unit42which captures the signal input to the input terminal41into the inside of the camera package1.

The input unit21A further includes an input amplitude changing unit43that changes the amplitude of the signal captured by the input circuit unit42to an amplitude that can be easily used inside the camera package1.

The input unit21A further includes an input data conversion circuit unit44that changes the arrangement of data strings of the input data. The input data conversion circuit unit44is, for example, a serial-parallel conversion circuit that receives a serial signal as input data and converts it into a parallel signal.

Note that the input amplitude changing unit43and the input data conversion circuit unit44may be omitted.

In a case where the camera package1is connected to external memory devices such as flash memory, SRAM, and DRAM, the input unit21A can be further provided with a memory interface circuit that receives data from these external memory devices.

The camera package1further includes an output unit21B. The output unit21B outputs image data captured by the camera package1and image data which has been subjected to signal processing by the image signal processor26from the camera package1to the outside of the device. The output unit21B includes an output terminal48which is an external terminal14for outputting data from the camera package1to the outside of the device, and an output circuit unit47that is a circuit for outputting data from the inside of the camera package1to the outside of the device and for driving an external wiring outside the camera package1connected to the output terminal48.

The output unit21B further includes an output amplitude changing unit46that changes the amplitude of the signal used inside the camera package1to an amplitude that can be easily used in an external device connected to the outside of the camera package1.

The output unit21B further includes an output data conversion circuit unit45that changes the arrangement of data strings of the output data. The output data conversion circuit unit45is, for example, a parallel-serial conversion circuit that converts a parallel signal used in the camera package1into a serial signal.

The output data conversion circuit unit45and the output amplitude changing unit46may be omitted.

In a case where the camera package1is connected to external memory devices such as flash memory, SRAM, and DRAM, the output unit21B can be further provided with a memory interface circuit that receives data from these external memory devices.

Note that, in the present disclosure, a circuit block including both or at least one of the input unit21A and/or the output unit21B may be referred to as an input/output unit21for the sake of convenience. Further, a circuit unit including both or at least one of the input circuit unit42and/or the output circuit unit47may be referred to as an input/output circuit unit49.

<3. Method for Forming Lens Resin Part>

Next, a method for forming the lens resin part19on the protective substrate18will be described with reference toFIGS.3A,3B,3C,3D, and3E.

First, contamination on the surface of the protective substrate18shown inFIG.3Ais removed by UV ozone cleaning using ultraviolet light (UV) and ozone (O3) or cleaning using a chemical solution. The cleaning using chemical solution may be performed by a cleaning method such as two-fluid cleaning or brush cleaning by using, for example, isopropyl alcohol (IPA), ethanol, acetone, etc.

After cleaning, the high contact angle film20is patterned on the upper surface of the protective substrate18as shown in-A ofFIG.3A. The high contact angle film20may be patterned by a lithography method, a screen printing method, an inkjet printing method, or the like. The high contact angle film20is formed in a region where a lens material501, which will be dropped in the next step, is not intended to be placed, in other words, a region other than the lens resin part19on the protective substrate18inFIG.1. As a material of the high contact angle film20, a fluorine-based resin, a silicone (Si—CH3)-based resin, or the like can be used, for example. Further, as the material of the high contact angle film20, a material having a function of blocking (absorbing or reflecting) light may be added or used. In this case, it is possible to simultaneously address the problem of flare and ghost by the high contact angle film20.

It is to be noted that, after the surface of the protective substrate18is cleaned and before the high contact angle film20is patterned, an adhesion promoter for improving adhesion between the lens material501to be dropped in the next step and the protective substrate18may be applied to the entire upper surface of the protective substrate18. The contact angle film of the adhesion promoter is smaller than that of the high contact angle film, and so, the high contact angle film has a large contact angle with respect to the adhesion promoter.

Next, as shown inFIG.3B, the lens material501is dropped in a predetermined region on the protective substrate18where the lens resin part19is to be formed, specifically, to the inside of the region where the high contact angle film20is formed. The dropping amount of the lens material501is substantially equal to the volume of the finished lens resin part19. The dropping position of the lens material501can be controlled with high accuracy with respect to an alignment mark formed at a predetermined position on the protective substrate18. The lens material501includes, for example, a resin material that is cured by ultraviolet light.

FIGS.4A,4B,4C, and4Dare plan views of the upper surface of the protective substrate18after the step of dropping the lens material501shown inFIG.3B.

The planar shape of the lens resin part19may be circular as shown inFIG.4Aor rectangular as shown inFIG.4B. The high contact angle film20is formed into a circular or rectangular shape depending on the planar shape of the lens resin part19to be formed. Since the high contact angle film20is formed on the upper surface of the protective substrate18, the dropped lens material501spreads only in the region where the high contact angle film20is not formed. Since the lens material501does not spread more than necessary in a planar direction, the lens material501in an amount corresponding to the volume of the lens resin part19has a bulky shape, so that it is possible to form a thick lens. It is to be noted that, in a case where the high contact angle film20is formed into a rectangular shape as shown inFIG.4, the rectangular region may be formed such that the lens formation region extends outward only in the vicinity of four corners as shown inFIGS.4C and4Din case the lens material501does not easily reach the four corners of the rectangle. The high contact angle film20may have any planar shape as long as the lens material501can definitely reach the four corners of the rectangle.

Returning to the description ofFIGS.3A,3B,3C,3D, and3E, the protective substrate18is placed and fixed by suction on a chuck502of an imprinting device, and in this state, a mold503which is attached to a mounting section504of the imprinting device and which has a concave-convex shape of the lens resin part19is pressed against the lens material501with a predetermined load at a predetermined speed as shown inFIG.3C. Thus, the concave-convex shape of the mold503is transferred to the lens material501dropped on the protective substrate18. The height at which the mold503is pressed against the lens material501is controlled according to the thickness of the lens resin part19. Similarly to the dropping position of the lens material501, the position of the mold503in the planar direction is controlled with high accuracy with respect to an alignment mark formed at a predetermined position on the protective substrate18. The surface of the mold503that comes into contact with the lens material501may be subjected to a mold release treatment in advance so that it can be easily separated from the cured lens material501.

Next, as shown inFIG.3D, ultraviolet light is emitted from above the mounting section504in a state where the mold503is pressed against the lens material501, whereby the lens material501is cured. A material that transmits ultraviolet light is used for the mounting section504and the mold503. It is to be noted that the chuck502may include a material that transmits ultraviolet light, and the lens material501may be cured by emitting ultraviolet light from below the chuck502. Alternatively, a thermosetting resin material may be used for the lens material501instead of an ultraviolet curable resin material, and the lens material501may be cured by heat treatment.

When the mold503is separated from the lens material501after the lens material501is cured, the lens resin part19shown inFIG.1is formed on the protective substrate18as shown inFIG.3E. The dropping amount of the lens material501is substantially equal to the volume of the finished lens resin part19, and the lens resin part19which is controlled with high accuracy without protrusion of the lens material501onto the high contact angle film20can be formed.

Note that, in a case where the dropping amount of the lens material501is set to be slightly greater than the amount corresponding to the volume of the finished lens resin part19, a light-shielding film (mask)505that does not transmit ultraviolet light can be formed on the side surface on the outer periphery of the mold503as shown inFIG.5. With this configuration, when the mold503is pressed against the lens material501, the lens material501protruding to the outside is not irradiated with ultraviolet light, so that it can be removed without being cured.

After the mold release shown inFIG.3E, an antireflection film may be formed on the outermost surface that is the upper surface of the lens resin part19and the upper surface of the high contact angle film20. Examples of the material of the antireflection film include a silicon oxide film, a silicon nitride film, and a silicon oxynitride film.

As described above, the lens resin part19is formed in such a way that the high contact angle film20is formed around the lens resin part19on the upper surface of the protective substrate18, the lens material501is dropped inside the high contact angle film20, and the dropped lens material501is molded using the mold503and cured. Due to the formation of the high contact angle film20around the lens resin part19, it is possible to form a thick lens having a bulky shape with a dropping amount of the lens material501corresponding to the volume of the finished lens resin part19. It is not necessary to drop an extra lens material501exceeding the volume of the lens shape, and it is also not necessary to provide an overflow section in the mold503. Therefore, the mold503can also be designed in a small size. Thus, the manufacturing cost required for lens formation can be reduced.

<Other Examples of Lens Formation Region>

FIGS.4C and4Dillustrate an example in which, in a case where the lens resin part19has a rectangular planar shape, a lens formation region to which the lens material501is dropped is formed so as to extend outward only in the vicinity of four corners with respect to the intended rectangular lens formation region in case the lens material501does not easily reach the four corners of the rectangle.

FIG.6shows another example of the lens formation region.

A rectangular region401represented by a broken line inFIG.6indicates the planar shape of the intended lens resin part19. On the other hand, a region402represented by a solid line indicates a lens formation region into which the lens material501is dropped in a case where the planar shape of the intended lens resin part19is the rectangular region401. The region outside the lens formation region in which the lens material501is dropped is a lens free region where the high contact angle film20is formed. The region402that separates the lens formation region from the lens free region has a shape in which portions corresponding to the apexes of the intended rectangular region401of the lens resin part19are curved to extend outward.

FIG.7illustrates the state before pressing inFIG.3Cin the step of forming the lens resin part19inFIGS.3A,3B,3C,3D, and3Eand the molding position (pressing state) inFIG.3D, in a case where the lens formation region in which the lens material501is dropped is formed as the region402which extends outward by curving the vicinity of four corners as shown inFIG.6.

By forming the lens formation region in which the lens material501is dropped as the region402which extends outward by curving the vicinity of four corners of the intended rectangle of the lens resin part19, it is possible to allow the lens material501to definitely reach the four corners as in four corner portions indicated by a broken line403, for example. This configuration can prevent an occurrence of appearance defect such as chips and voids which may be caused due to insufficient amount of required liquid because the lens material501does not spread to the four corners of the intended rectangle of the lens resin part19.

The details of the region402in which the lens material501is dropped will be described with reference toFIG.8.

Note that, inFIG.8, a region411indicates an enlarged portion of four corners of the region402in which the lens material501is dropped, and a region412inFIG.8indicates an enlarged short side of the region402.

The region402in which the lens material501is dropped is formed by connecting a plurality of curves that is externally in contact with (circumscribes) the intended rectangular region401of the lens resin part19.

More specifically, the region402includes a line segment AE formed by connecting a curve AB connecting points A and B, a curve BC connecting points B and C, a curve CD connecting points C and D, and a curve DE connecting points D and E, and a line segment EA which is symmetrical with respect to the line segment AE about a center O (hereinafter also referred to as a molding center O) of the intended rectangular region401of the lens resin part19.

The curve AB corresponds to a given long side of the intended rectangular region401of the lens resin part19, and is constituted by, for example, an arc which circumscribes the long side and which has a predetermined radius of curvature rAB. The curve BC is constituted by, for example, an arc having a predetermined radius of curvature rBC. The curve CD corresponds to a given short side of the rectangular region401, and is constituted by, for example, an arc which circumscribes the short side and which has a predetermined radius of curvature rCD. The curve DE is constituted by an arc having the same radius of curvature rBCas the curve BC.

Therefore, in other words, the region402is a closed region enclosed by the curve AB which circumscribes a given long side of the intended rectangular region401of the lens resin part19and which has a predetermined radius of curvature rAB, the curve CD which circumscribes a given short side of the intended rectangular region401and which has a predetermined radius of curvature rCD, the curve BC which connects the curve AB and the curve CD and which has a predetermined radius of curvature rBC, and the curve DE which is connected to the other end of the curve CD that is not connected to the curve BC and which has the same radius of curvature rBCas the curve BC, the closed region being formed by placing the curves AB, the curves BC, the curves CD, and the curves DE in a symmetrical manner about the molding center O.

The curve AB circumscribing one given long side of the intended rectangular region401of the lens resin part19and the curve CD circumscribing one given short side of the rectangular region401are not necessarily an arc having a predetermined radius of curvature, and it is only sufficient that they form smooth curves extending outward in a direction away from the molding center O with respect to the intended rectangular region401of the lens resin part19.

Further, the curve BC and the curve DE that connect the curve AB and the curve CD do not necessarily need to have an arc having a predetermined radius of curvature, and may be any smooth curve.

Furthermore, the region may have a shape in which an end point B of the curve AB and an end point C of the curve CD which is near the end point B are connected by a straight line as shown inFIG.9A, or the end point B of the curve AB and the end point C of the curve CD near the end point B may be connected as a point as shown inFIG.9B, for example.

FIGS.9A and9Bare diagrams showing a modification of the region402in which the lens material501is dropped, and show only the region412which is an enlarged view of the short side of the region402.

As described above, the region402in which the lens material501is dropped has a shape in which the curve AB circumscribing one given long side of the intended rectangular region401of the lens resin part19and the curve CD circumscribing one given short side of the rectangular region401are connected to each other with a smooth curve, a straight line, or a point, and the curve AB circumscribing the long side and the curve CD circumscribing the short side extend outward from the intended rectangular region401of the lens resin part19with nearness to the four corners (points distant from the molding center O) of the rectangular region401from the center O (lens center O) of the rectangular region401.

Due to the configuration in which such region402is formed as the lens formation region, the lens material501that may protrude at the middle of sides of the intended rectangular region401of the lens resin part19can be guided to the four corners when the lens material501is dropped and the mold503is pressed against the lens material501.

The abovementioned embodiment has described the configuration that enables formation of a bulky and thick lens with a dropping amount of the lens material501corresponding to the volume of the finished lens resin part19by giving water repellency due to formation of the high contact angle film20in the lens free region other than the lens formation region which serves as the lens resin part19on the protective substrate18.

Meanwhile, it is sufficient that the lens formation region where the lens resin part19is to be formed and the lens free region differ in contact angle. Therefore, it is also possible to form a bulky and thick lens with a dropping amount of the lens material501corresponding to the volume of the finished lens resin part19by forming a hydrophilic film that has a low contact angle in the lens formation region instead of forming the high contact angle film20in the lens free region.

For example,FIG.10Ashows a state in which the lens material501is dropped with the high contact angle film20being formed in the lens free region described in the abovementioned embodiment. Here, the region402inFIG.6or the region in which the lens material501is dropped inFIGS.4A,4B,4C, and4Dare used as the region where the lens material501is dropped, for example.

FIG.10Bshows a state in which the lens material501is dropped with a hydrophilic film421having hydrophilic property (low contact angle) being formed in the lens formation region without forming the high contact angle film20in the lens free region. As the material of the hydrophilic film421, a resin material such as an acrylic resin or urethane resin containing a hydrophilic group and having a photoreactive functional group can be used, for example. The lens formation region needs to transmit incident light, and thus, it is obvious that a light transmissive material is used for the hydrophilic film421.

FIG.10Cshows a state in which the lens material501is dropped with the hydrophilic film421having hydrophilic property being formed in the lens formation region and the high contact angle film20being formed in the lens free region.

FIGS.10A,10B, and10Care cross-sectional views corresponding toFIG.3B. After the lens material501is dropped in the lens formation region as shown inFIGS.10A,10B, and10C, the mold503having a concave-convex shape of the lens resin part19is pressed against the lens material501with a predetermined load at a predetermined speed, and then, ultraviolet light is emitted to cure the lens material501as described with reference toFIGS.3C,3D, and3E.

It is to be noted that a state having a high contact angle can be formed by irradiating the surface of the lens free region of the protective substrate18with an ultrashort pulsed-laser beam to form micro-irregularities, instead of forming the high contact angle film20in the lens free region.

As described above, it is only sufficient that there is a difference in contact angle between the lens free region and the lens formation region of the protective substrate18, and the high contact angle film20or the hydrophilic film421may be provided or may not be provided. A process of forming at least one of the high contact angle film20or the hydrophilic film421may be used, or a process of emitting an ultrashort pulsed-laser beam to form micro-irregularities may be used.

The measurement of contact angles was performed to find out the specific difference in contact angle between the lens formation region where the lens resin part19is to be formed and the lens free region where the lens resin part19is not formed in order to enable formation of a bulky and thick lens with the minimum necessary lens material501. According to the measurement, the contact angle of 27.4 degrees of the lens formation region and the contact angle of 38.5 degrees of the lens free region were obtained as shown inFIG.11, for example. It is possible to form a bulky and thick lens with the minimum necessary lens material501, if there is a difference in contact angle by 10 degrees or more between the lens formation region and the lens free region.

<Structure in which Difference in Height is Generated in Lens Formation Region>

Next, a method for forming the lens resin part19with which performance for holding the lens material501is improved and an occurrence of appearance defect such as chips or voids is prevented other than the method for forming the high contact angle film20having water repellency or the method for forming the hydrophilic film421having hydrophilic property will be described.

FIG.12is a cross-sectional view showing another configuration example of the protective substrate that enhances the performance for holding the lens material501.

A protective substrate18A shown inFIG.12is different from the protective substrate18inFIG.1or other drawings in that the lens formation region in which the lens resin part19is formed is provided with a recessed part441that is lower in height than the lens free region around the lens formation region. The lens resin part19is embedded in the recessed part441of the protective substrate18A, and the upper surface of the lens resin part19has a shape as a lens for allowing the incident light to enter a predetermined pixel of the upper structure11(FIG.1) by refracting the incident light in a predetermined direction.

FIG.13shows the state before pressing inFIG.3Cand the state of the molding position inFIG.3Din the process of forming the lens resin part19inFIGS.3A,3B,3C,3D, and3Eusing the protective substrate18A provided with the recessed part441.

The lens material501of the lens resin part19is dropped in the recessed part441of the protective substrate18A, and irradiated with ultraviolet light in a state where the mold503having a concave-convex shape of the lens resin part19is pressed against the lens material501with a predetermined load at a predetermined speed, by which the lens material501is cured.

As described above, in a case where the protective substrate18A is provided with the recessed part441, performance for holding the lens material501is enhanced by the angular structure due to a difference in height and the liquid surface tension. Further, since the contact area with the protective substrate18A is increased as compared with the case where the lens formation region is flat, the peeling resistance of the lens resin part19after curing is improved.

Regarding the degree of spread of the lens material501in the planar direction, an increase in contact area is advantageous for spreading the lens material501, so that the lens material501spreads to the corners. Further, since a barrier is formed due to the difference in height, the protrusion of the lens material501is also suppressed.

Therefore, according to the protective substrate18A provided with the recessed part441, it is possible to improve the performance for holding the lens material501and prevent the occurrence of appearance defects such as chips and voids.

The protective substrate18A provided with the recessed part441may be combined with at least one of the high contact angle film20or the hydrophilic film421described with reference toFIGS.10A,10B, and10C.

FIG.14Ashows a state in which the lens material501is dropped with the high contact angle film20being formed in the lens free region of the protective substrate18A provided with the recessed part441.

FIG.14Bshows a state in which the lens material501is dropped with the hydrophilic film421being formed in the lens formation region of the protective substrate18A provided with the recessed part441.

FIG.14Cshows a state in which the lens material501is dropped with the hydrophilic film421having hydrophilic property being formed in the lens formation region of the protective substrate18A provided with the recessed part441and the high contact angle film20being formed in the lens free region.

By using the protective substrate18A provided with the recessed part441in combination with at least one of the high contact angle film20or the hydrophilic film421, the performance for holding the lens material501can be further enhanced, and the occurrence of appearance defects can be prevented.

Note that, although the protective substrate18A has the recessed part441formed by cutting the substrate, it is only sufficient that there is a difference in height between the lens formation region where the lens resin part19is to be formed and the lens free region around the lens formation region. Therefore, the recessed part441may be formed by providing a thick film451in the lens free region of the flat protective substrate18as shown inFIG.15A, for example. As the material of the thick film451, a resin material that can be patterned such as a resist material, an inorganic film such as SiO2 or a metal film, or the like can be used, for example. Alternatively, the thickness of the high contact angle film20having water repellency may be increased.

FIG.15Bshows a state in which the hydrophilic film421is further formed in the lens formation region of the protective substrate18provided with the recessed part441that is formed by providing the thick film451in the lens free region.

FIG.15Cshows a state in which the high contact angle film20is further formed on the upper surface of the thick film451in the lens free region of the protective substrate18provided with the recessed part441that is formed by providing the thick film451in the lens free region.

In this way, the protective substrate18having the recessed part441formed by providing the thick film451in the lens free region may be combined for use with the high contact angle film20having water repellency or the hydrophilic film421having hydrophilic property described above.

FIGS.16A,16B, and16Cshow modifications of the protective substrate18A provided with the recessed part441.

FIG.16Ashows an example of the protective substrate18A in which the side wall of the recessed part441has a tapered shape so that the opening on the upper surface side is larger than that on the bottom surface side.

FIG.16Bshows an example of the protective substrate18A in which the side wall of the recessed part441has an inverted tapered shape so that the opening on the upper surface side is smaller than that on the bottom surface side.

FIG.16Cshows an example of the protective substrate18A in which the side wall of the recessed part441has a curved shape that projects outward of the lens. Contrary to the example ofFIG.16C, the side wall of the recessed part441may have a curved surface that projects to the center of the lens.

It is only sufficient that the recessed part441generates a difference in height between the uppermost surface of the protective substrate18A and the flat surface of the lens formation region, and therefore, the side wall of the recessed part441may have any shape as in the examples ofFIGS.16A,16B, and16C.

FIGS.17A,17B,17C, and17Dare cross-sectional views showing another configuration example of the protective substrate that enhances performance for holding the lens material501.

Note thatFIGS.17A,17B,17C, and17Dshow states before the lens material501dropped in the recessed part441is molded.

A protective substrate18B shown inFIG.17Ahas a structure in which a bank471that blocks the outflow of the lens material501is added to the outer peripheral portion of the protective substrate18A provided with the recessed part441shown inFIG.12in the planar direction of the lens material501.

A protective substrate18C shown inFIG.17Bhas a structure similar to that of the protective substrate18B shown inFIG.17Aexcept that the bottom surface of the recessed part441is curved to project downward. In the protective substrate18C shown inFIG.17B, the bottom surface of the recessed part441is curved to project downward, but it may be curved to project upward.

A protective substrate18D shown inFIG.17Chas a structure similar to that of the protective substrate18B shown inFIG.17Aexcept that the bottom surface of the recessed part441is formed into a circular cone or polygonal pyramid that projects upward with the lens center as a vertex, and the outer peripheral portion contacting the side surface is the lowest in height.

According to the structure of the protective substrate18D, the recessed part441is formed such that the outer peripheral portion of the bottom surface is the lowest in height, so that the lens material501is less likely to leak from the recessed part441(lens formation region).

A protective substrate18E shown inFIG.17Dhas a structure similar to that of the protective substrate18B shown inFIG.17Aexcept that the bottom surface of the recessed part441has a recessed and projected pattern having a predetermined cycle.

According to the structure of the protective substrate18E having the periodic recessed and projected pattern formed on the bottom surface of the recessed part441, the lens material501is less likely to leak from the recessed part441, and the adhesion between the protective substrate18E and the lens material501(lens resin part19) is improved. Note that the recessed and projected pattern may be random, not periodic.

As described with reference toFIGS.12,13,14A,14B,14C,15A,15B,15C,16A,16B,16C,17A,17B,17C, and17D, each of the protective substrates18A to18E includes a recessed part441, and the average height of the lens formation region is lower than the average height of the lens free region when a predetermined plane parallel to the surface of the substrate is defined as a reference position in the height direction. A difference in height between the surface of the lens formation region and the surface of the lens free region may be formed by recessing the substrate of the lens formation region or by forming a thick film451in the lens free region of the flat substrate. Further, the bottom surface of the recessed part441may be a recessed surface, a projecting surface, an uneven surface, an inclined surface, or the like, and it is not necessary that the entire bottom surface has a uniform height. The side surface (side wall) of the recessed part441may also be a recessed surface, a projecting surface, an uneven surface, an inclined surface, or the like.

Due to the difference in height between the surface of the lens formation region and the surface of the lens free region, the performance for holding the lens material501can be enhanced, and an occurrence of appearance defects due to insufficient liquid can be prevented. Further, the contact area with the substrate is increased, whereby the peeling resistance of the lens resin part19can be improved.

<4. Timing of Formation of Lens Resin Part>

FIGS.18A and18Bare diagrams for describing a timing at which the process of forming the lens resin part19described with reference toFIGS.3A,3B,3C,3D, and3Eare performed.

FIG.18Ashows a method for forming the lens resin part19on the upper surface of the protective substrate18by the method described with reference toFIGS.3A,3B,3C,3D, and3Eafter the protective substrate18is disposed above the solid-state imaging element13.

On the other hand,FIG.18Bshows a method in which the lens resin part19is formed in advance on the upper surface of the protective substrate18with the method described with reference toFIGS.3A,3B,30,3D, and3E, and then, the protective substrate18having the lens resin part19formed thereon is placed above the on-chip lens16or the color filter15of the solid-state imaging element13at any timing.

As described above, the lens resin part19may be formed on the protective substrate18that has been combined with the solid-state imaging element13, or the lens resin part19may be formed on the protective substrate18, and then, the protective substrate18may be combined with the solid-state imaging element13.

Further, althoughFIGS.3A,3B,3C,3D, and3Eshow a lens formation method for forming the lens resin part19, focusing on one lens resin part19, the method described with reference toFIGS.3A,3B,3C,3D, and3Ecan also be applied to a wafer-level lens process for simultaneously forming multiple lens resin parts19in the planar direction of the protective substrate18.

That is, as shown inFIG.19, a large number of lens resin parts19can be collectively formed on a device substrate552by an imprinting process using a wafer replica substrate551having multiple molds503shown inFIGS.3A,3B,3C,3D, and3Earrayed in the planar direction.

Alternatively, as shown inFIG.20, multiple lens resin parts19can be formed on the device substrate552in such a way that a single mold503is used, and the position of the mold503on the device substrate552is changed to sequentially form the lens resin part19on the device substrate552.

The device substrate552inFIGS.19and20corresponds to a wafer substrate in which the protective substrate18is formed above the solid-state imaging element13before the lens resin part19is formed as shown in the upper chart inFIGS.18A and18B, corresponds to the protective substrate18in a wafer form before the lens resin part19is formed.

FIGS.21and22show modifications of the camera package1shown inFIG.1.

It has been described in the description with reference toFIGS.3A,3B,3C,3D, and3Ethat an adhesion promoter which improves the adhesion between the lens material501and the protective substrate18may be formed on the entire upper surface of the protective substrate18.

FIG.21shows a cross-sectional view of the camera package1in a case where an adhesion promoter is formed on the upper surface of the protective substrate18.

As shown inFIG.21, an adhesion promoter571is formed on the entire upper surface of the protective substrate18, and the lens resin part19and the high contact angle film20are formed on the adhesion promoter571.

The high contact angle film20has a property of having a larger contact angle than the adhesion promoter571. Therefore, even in a case where the adhesion promoter571is formed on the entire upper surface of the protective substrate18, the lens resin part19having a bulky shape can be formed by an amount corresponding to the volume of the lens resin part19as described with reference toFIGS.3A,3B,3C,3D, and3E.

It is to be noted that, instead of the adhesion promoter571, another film, for example, an IR cut filter that blocks IR light, may be formed in the camera package1. In addition, the IR cut filter and the adhesion promoter571may be laminated.

FIG.22is a diagram showing another example of the shape of the lens resin part19.

The lens resin part19may have any shape as long as it exhibits performance as a lens, and may have a shape shown inFIG.22, for example. The shape of the mold503is also changed depending on the shape of the lens resin part19.

Further, in the camera package1shown inFIG.22, an antireflection film572is formed on the upper surface of the lens resin part19and the upper surface of the high contact angle film20. As described above, a material that absorbs or reflects light may be added as the material of the high contact angle film20, or as shown inFIG.22, the antireflection film572may be formed on the upper surface of the lens resin part19and the high contact angle film20. With this configuration, flare and ghost can be suppressed.

<6. First Formation Method for Forming High Contact Angle Film>

The method for forming the lens resin part19described with reference toFIGS.3A,3B,3C,3D, and3Einclude the method for forming the lens resin part19after the protective substrate18is bonded above the solid-state imaging element13as described with reference toFIG.18Aand the method for forming the lens resin part19before the protective substrate18is bonded as described with reference toFIG.18B.

During patterning of the high contact angle film20shown inFIG.3Ain the case where the lens resin part19is formed after the protective substrate18is bonded as described with reference toFIG.18A, the high contact angle film20is exposed using a photomask122having a light-shielding pattern121formed in a region of the lens resin part19as shown inFIG.23, for example. During exposure, exposure light may transmit the high contact angle film20, the protective substrate18, and the like, enter again the protective substrate18by being reflected by the semiconductor substrate (silicon substrate) of the upper structure11of the solid-state imaging element13, and enter the region of the light-shielding pattern121of the photomask122, as indicated by an arrow inFIG.23. As a result, patterning defect of the high contact angle film20may occur.

In view of this, a method for forming the high contact angle film20capable of preventing the occurrence of patterning defect of the high contact angle film20will be described below.

The first to fourth formation methods for forming the high contact angle film20described below are intended to prevent patterning defect of the high contact angle film20that occurs when the lens resin part19is formed after the protective substrate18is bonded above the solid-state imaging element13. Therefore, the premise is that the protective substrate18is bonded above the solid-state imaging element13with the sealing resin17. However, they may be applied to the case where the high contact angle film20is formed on the protective substrate18before the protective substrate18is bonded to the solid-state imaging element13described with reference toFIG.18B.

The first formation method for forming the high contact angle film will be described with reference toFIGS.24A,24B,24C,24D,24E, and24F.

Note that, inFIGS.24A,24B,24C,24D,24E, and24F, the portion below the upper structure11of the solid-state imaging element13(external terminal14side) is not illustrated.

First, as shown inFIG.24A, the surface of the protective substrate18is cleaned with UV ozone or a chemical solution, and then, an adhesion promoter131for improving adhesion between the lens material501which is to be dropped in the subsequent step (FIG.3B) and the protective substrate18is formed on the upper surface of the protective substrate18.

Next, as shown inFIG.24B, a light absorbing film132that absorbs exposure light for patterning the high contact angle film20is formed on the upper surface of the adhesion promoter131using, for example, a spin coating method. Note that the method for forming the light absorbing film132is not limited to the spin coating method, and any method such as spraying, dipping, method using squeegee, and inkjet, may be used as long as a thin film can be formed. The exposure light is, for example, UV light, and the light absorbing film132that absorbs UV light can be, for example, a black resist or an antireflection film.

Next, as shown inFIG.24C, exposure is performed using the photomask122having the light-shielding pattern121formed in the region of the lens resin part19. The light absorbing film132is formed only around the region where the lens resin part19is to be formed, and the light absorbing film132in the region where the lens resin part19is to be formed is removed.

Next, the high contact angle film20is patterned in the similar manner to the light absorbing film132. Specifically, after the high contact angle film20is formed on the entire upper surfaces of the adhesion promoter131and the light absorbing film132as shown inFIG.24D, exposure is performed using the photomask122having the light-shielding pattern121formed thereon as shown inFIG.24E. Thus, as shown inFIG.24E, the high contact angle film20is formed only on the upper surface of the light absorbing film132, in other words, in the same region as the region where the light absorbing film132is formed.

The difference between the cross-sectional configuration inFIG.1andFIG.3Aand the cross-sectional configuration inFIG.24Eis that the light absorbing film132is formed between the high contact angle film20and the protective substrate18. Due to the light absorbing film132formed around the region where the lens resin part19is to be formed, light for exposing the region other than the lens resin part19is prevented from transmitting the protective substrate18and the like and reaching the semiconductor substrate of the upper structure11of the solid-state imaging element13as indicated by the arrow inFIG.23. Therefore, the occurrence of patterning defect of the high contact angle film20due to the reflection from the semiconductor substrate can be suppressed.

Note that, although the light absorbing film132is formed between the adhesion promoter131and the high contact angle film20in the above example, it may be formed between the sealing resin17and the protective substrate18or between the upper structure11and the sealing resin17.

Further, the adhesion promoter131may be provided between the light absorbing film132and the high contact angle film20instead of between the protective substrate18and the light absorbing film132. Alternatively, it may be formed both between the protective substrate18and the light absorbing film132and between the light absorbing film132and the high contact angle film20.

Further, the light absorbing film132may be used as a light reflection film that reflects light. In that case, light for exposing the region other than the lens resin part19is reflected without transmitting to the protective substrate18side, whereby the occurrence of patterning defect of the high contact angle film20due to reflection from the semiconductor substrate of the upper structure11can also be suppressed. The light reflection film can be constituted by, for example, a metal film such as Al, Ti, W, Ta, or Cu.

In addition to providing the abovementioned light absorbing film132, an antireflection structure for suppressing reflection of light may further be added to the surface of the substrate of the upper structure11. For example, an antireflection film or a moth-eye structure may be formed on the surface on the light-receiving surface side of the semiconductor substrate (silicon substrate) of the upper structure11.

<7. Second Formation Method for Forming High Contact Angle Film>

Next, the second formation method for forming the high contact angle film will be described with reference toFIGS.25A,25B,250,25D, and25E.

Note that the portions inFIGS.25A,25B,250,25D, and25Ecorresponding to those inFIGS.24A,24B,24C,24D,24E, and24Fare identified by the same reference numerals. Further, the portion below the upper structure11of the solid-state imaging element13(external terminal14side) is not illustrated as inFIGS.24A,24B,24C,24D,24E, and24F.

First, as shown inFIG.25A, the surface of the protective substrate18is cleaned with UV ozone or a chemical solution, and then, the adhesion promoter131is formed on the upper surface of the protective substrate18in the similar manner to the first formation method.

Next, as shown inFIG.25B, a light absorbing film135that absorbs exposure light for patterning the high contact angle film20is formed on the upper surface of the adhesion promoter131using, for example, a spin coating method. The light absorbing film135absorbs the wavelength of light (for example, UV light) for curing the high contact angle film20and transmits the wavelength of light (for example, visible light) required for the solid-state imaging element13. As the light absorbing film135having such characteristic, a silicon nitride film, a colorless color filter that absorbs only UV light, or the like can be used, for example.

Note that the method for forming the light absorbing film135is not limited to the spin coating method, and any method such as spraying, dipping, method using squeegee, and inkjet, may be used as long as a thin film can be formed.

Next, the high contact angle film20is patterned on the upper surface of the light absorbing film135as shown inFIGS.25C,25D, and25E. That is, after the high contact angle film20is formed on the entire upper surface of the light absorbing film135as shown inFIG.25C, exposure is performed using the photomask122in which the light-shielding pattern121is formed corresponding to the region of the lens resin part19as shown inFIG.25D. As a result, as shown inFIG.25E, the high contact angle film20in the region of the light-shielding pattern121is removed without being cured, and the high contact angle film20is formed in the region other than the lens resin part19.

The difference between the cross-sectional configuration inFIG.24Eand the cross-sectional configuration inFIG.25Eis that, in the cross-sectional configuration inFIG.24F, the light absorbing film132is formed only around the region where the lens resin part19is to be formed, whereas in the cross-sectional configuration inFIG.25E, the light absorbing film135is formed on the entire upper region of the solid-state imaging element13including the region where the lens resin part19is to be formed and the region therearound. Therefore, in the third formation method, a film that transmits the wavelength of light (for example, visible light) received by the solid-state imaging element13is used for the light absorbing film135.

Due to the formation of the light absorbing film135, light for exposing the region other than the lens resin part19is prevented from transmitting the protective substrate18and the like and reaching the semiconductor substrate of the upper structure11of the solid-state imaging element13as indicated by the arrow inFIG.23. Therefore, the occurrence of patterning defect of the high contact angle film20due to the reflection from the semiconductor substrate can be suppressed.

Note that, although the light absorbing film135is formed between the adhesion promoter131and the high contact angle film20in the above example, it may be formed between the sealing resin17and the protective substrate18or between the upper structure11and the sealing resin17.

Further, the adhesion promoter131may be provided between the light absorbing film135and the high contact angle film20instead of between the protective substrate18and the light absorbing film135. Alternatively, it may be formed both between the protective substrate18and the light absorbing film135and between the light absorbing film135and the high contact angle film20.

In addition to providing the abovementioned light absorbing film135, an antireflection structure for suppressing reflection of light may further be added to the surface of the substrate of the upper structure11. For example, an antireflection film or a moth-eye structure may be formed on the surface on the light-receiving surface side of the semiconductor substrate (silicon substrate) of the upper structure11.

<8. Third Formation Method for Forming High Contact Angle Film>

Next, the third formation method for forming the high contact angle film will be described with reference toFIGS.26A,26B,26C, and26D.

Note that the portions inFIGS.26A,26B,26C, and26Dcorresponding to those inFIGS.25A,25B,250,25D, and25Eare identified by the same reference numerals. Further, the portion below the upper structure11of the solid-state imaging element13(external terminal14side) is not illustrated as inFIGS.25A,25B,250,25D, and25E.

In the third formation method, the high contact angle film20is replaced with a high contact angle film20′, and the high contact angle film20′ is patterned on the upper surface of the protective substrate18or the adhesion promoter131. Here, the high contact angle film20′ is added with a light absorbing material as a material and has a characteristic of absorbing exposure light for patterning the high contact angle film20′.

Specifically, first, as shown inFIG.26A, the surface of the protective substrate18is cleaned with UV ozone or a chemical solution, and then, the adhesion promoter131is formed on the upper surface of the protective substrate18in the similar manner to the second formation method.

Next, the high contact angle film20′ having optical absorption property is patterned on the upper surface of the adhesion promoter131. Specifically, after the high contact angle film20′ is formed on the entire upper surface of the adhesion promoter131as shown inFIG.26B, exposure is performed using the photomask122in which the light-shielding pattern121is formed corresponding to the region of the lens resin part19as shown inFIG.26C. As a result, as shown inFIG.26D, the high contact angle film20′ in the region of the light-shielding pattern121is removed without being cured, and the high contact angle film20′ is formed in the region other than the lens resin part19.

Note that any method, such as spin coating, spraying, dipping, method using squeegee, and inkjet, with which it is possible to form a thin film may be used for forming the high contact angle film20′ on the entire upper surface of the adhesion promoter131.

The difference between the cross-sectional configuration shown inFIG.24Eand the cross-sectional configuration shown inFIG.26Dis that, in the cross-sectional configuration shown inFIG.24E, the patterned light absorbing film132is formed, whereas in the cross-sectional configuration shown inFIG.26D, the light absorbing film132is not formed. Instead, in the cross-sectional configuration shown inFIG.26D, the high contact angle film20′ having optical absorption property is used in place of the high contact angle film20having no optical absorption property.

Due to the high contact angle film20′ having optical absorption property, light for exposing the region other than the lens resin part19is prevented from transmitting the protective substrate18and the like and reaching the semiconductor substrate of the upper structure11of the solid-state imaging element13as indicated by the arrow inFIG.23. Therefore, the occurrence of patterning defect of the high contact angle film20′ due to the reflection from the semiconductor substrate can be suppressed.

Note that, in addition to the configuration using the high contact angle film20′ having optical absorption property, an antireflection structure for suppressing reflection of light may further be added to the surface of the substrate of the upper structure11. For example, an antireflection film or a moth-eye structure may be formed on the surface on the light-receiving surface side of the semiconductor substrate (silicon substrate) of the upper structure11.

<9. Fourth Formation Method for Forming High Contact Angle Film>

Next, the fourth formation method for forming the high contact angle film will be described with reference toFIGS.27A,27B,27C,27D, and27E.

Note that the portions inFIGS.27A,27B,27C,27D, and27Ecorresponding to those inFIGS.26A,26B,26C, and26Dare identified by the same reference numerals. Further, the portion below the upper structure11of the solid-state imaging element13(external terminal14side) is not illustrated as inFIGS.26A,26B,26C, and26D.

In the fourth formation method, as shown inFIG.27A, a protective substrate18′ is used in place of the protective substrate18as the protective substrate bonded to the upper structure11of the solid-state imaging element13using the sealing resin17. The protective substrate18′ is a transparent substrate including a material having optical absorption property, and is, for example, a glass substrate using borosilicate glass.

Thereafter, as shown inFIG.27B, the surface of the protective substrate18′ is cleaned with UV ozone or a chemical solution, and then, the adhesion promoter131is formed on the upper surface of the protective substrate18′.

Then, the high contact angle film20is patterned on the upper surface of the adhesion promoter131in the similar manner. That is, after the high contact angle film20is formed on the entire upper surface of the adhesion promoter131as shown inFIG.27C, exposure is performed using the photomask122in which the light-shielding pattern121is formed corresponding to the region of the lens resin part19as shown inFIG.27D. As a result, as shown inFIG.27E, the high contact angle film20in the region of the light-shielding pattern121is removed without being cured, and the high contact angle film20is formed in the region other than the lens resin part19.

Note that any method, such as spin coating, spraying, dipping, method using squeegee, and inkjet, with which it is possible to form a thin film may be used for forming the high contact angle film20on the entire upper surface of the adhesion promoter131.

The difference between the cross-sectional configuration shown inFIG.27Eand the cross-sectional configuration shown inFIG.26Dis that, in the cross-sectional configuration shown inFIG.26D, the high contact angle film20′ patterned on the adhesion promoter131has optical absorption property, whereas in the cross-sectional configuration shown inFIG.27E, the high contact angle film20does not have optical absorption property, but the protective substrate18′ has optical absorption property.

Due to the protective substrate18′ having optical absorption property, light for exposing the region other than the lens resin part19is prevented from transmitting the protective substrate18′ and the like and reaching the semiconductor substrate of the upper structure11of the solid-state imaging element13as indicated by the arrow inFIG.23. Therefore, the occurrence of patterning defect of the high contact angle film20due to the reflection from the semiconductor substrate of the upper structure11can be suppressed.

In addition to providing the protective substrate18′ having optical absorption property, an antireflection structure for suppressing reflection of light may further be added to the surface of the substrate of the upper structure11. For example, an antireflection film or a moth-eye structure may be formed on the surface on the light-receiving surface side of the semiconductor substrate (silicon substrate) of the upper structure11.

Note that, although the high contact angle film20having no optical absorption property is used in the fourth formation method described above, the high contact angle film20′ having optical absorption property may be used. That is, light for exposing the region other than the lens resin part19may be prevented from reaching the semiconductor substrate of the upper structure11of the solid-state imaging element13by using both the protective substrate18′ having optical absorption property and the high contact angle film20′ having optical absorption property.

In the abovementioned first and second formation methods for forming the high contact angle film, a light absorbing film (light absorbing film132or135) having optical absorption property is formed between the high contact angle film20and the upper structure11, and in the third and fourth formation methods for forming the high contact angle film, the high contact angle film20′ or the protective substrate18′ having optical absorption property is used without using a light absorbing film.

With these methods, light for exposing the region other than the lens resin part19is prevented from transmitting the protective substrate18and the like and reaching the semiconductor substrate of the upper structure11of the solid-state imaging element13as indicated by the arrow inFIG.23. Therefore, the occurrence of patterning defect of the high contact angle film20due to the reflection from the semiconductor substrate can be suppressed.

Further, in a case where UV light is used as light for exposing the high contact angle film20, the irradiation of the sealing resin17with UV light can be suppressed, so that the deterioration of the sealing resin17due to UV light can be reduced. Further, in a case where the solid-state imaging element13is an imaging element that receives visible light (RGB light), a UV blocking effect of cutting (blocking) UV light is also exhibited. In addition, it is also possible to suppress flare and ghost.

The abovementioned example has described the case where the high contact angle film20is utilized during a process of molding the lens resin part19by transferring the concave-convex shape of the mold503to the lens material501. The formation of the high contact angle film can also be used for a process of forming the mold503in a similar manner.

FIGS.28A,28B,28C, and28Dshow an example of a process of forming the mold503.

As shown inFIG.28A, a light-shielding film582, an adhesion promoter583, and a high contact angle film584are formed in this order on a substrate581. The light-shielding film582is formed in a region other than a region in which a mold material591that is to be the mold503is to be formed in a step shown in-D ofFIG.28Dto be described later. The adhesion promoter583and the high contact angle film584are formed on the entire surface.

Next, as shown inFIGS.28B and28C, the high contact angle film584is exposed and etched using a mask585in which a pattern is formed corresponding to a region where the high contact angle film584is to be formed, whereby the high contact angle film584is patterned in a desired region. The region in which the high contact angle film584is formed is a region other than the region in which the mold503is to be formed as in the step shown inFIG.3A.

Then, as shown inFIG.28D, the material (mold material)591for the mold503is dropped on an upper surface of the adhesion promoter583formed on the substrate581, a mold592on which the concave-convex shape of the mold503is transferred is pressed against the mold material591, and the mold material591is cured. Thus, the mold503is manufactured.

During the process of manufacturing the mold503described above, the high contact angle film584is formed in the region other than the region where the mold503is to be formed, whereby the mold503can be manufactured by dropping the mold material591only in an amount corresponding to the volume of the mold503. Thus, the mold503can be efficiently manufactured. It is to be noted that, although the mold592is pressed against the substrate581in the above example, pressing step is not necessarily needed, and the mold592may be controlled to have a predetermined space from the substrate581.

<11. Schematic Structure of Camera Package without Having High Contact Angle Film>

Next, a method for forming the lens resin part19without using the high contact angle film20will be described.

FIG.29shows a schematic structure of a camera package1which does not have the high contact angle film20.

The configuration of the camera package1inFIG.29is similar to that of the camera package1shown inFIG.1except that the high contact angle film20is not formed around the lens resin part19, so that the description thereof will be omitted.

A lens formation method for forming the lens resin part19on the protective substrate18without using the high contact angle film20will be described with reference toFIGS.30A,30B,30C, and30D.

Note that, althoughFIGS.30A,30B,30C, and30Dshow a lens formation method for forming one lens resin part19, this method can also be applied to a wafer-level lens process for simultaneously forming multiple lens resin parts19in the planar direction of the protective substrate18.

First, as shown inFIG.30A, the protective substrate18is placed and fixed on a chuck601by suction, and with this state, contamination on the surface of the protective substrate18is removed by UV ozone cleaning using ultraviolet light (UV) and ozone (O3), cleaning using a chemical solution, or the like. The cleaning using chemical solution may be performed by a cleaning method such as two-fluid cleaning or brush cleaning by using, for example, isopropyl alcohol (IPA), ethanol, acetone, etc. After the surface of the protective substrate18is cleaned, an adhesion promoter (not shown) for improving the adhesion between a lens material602to be dropped in the next step and the protective substrate18is formed.

Next, as shown inFIG.30B, the lens material602is dropped to a predetermined position on the protective substrate18where the lens resin part19is to be formed. The dropping position of the lens material602can be controlled with high accuracy with respect to an alignment mark formed at a predetermined position on the protective substrate18. The lens material602includes, for example, a resin material that is cured by ultraviolet light.

Next, as shown inFIG.30C, a mold603which is attached to a mounting section604of an imprinting device and which has a concave-convex shape of the lens resin part19is pressed against the protective substrate18with a predetermined load at a predetermined speed. Thus, the concave-convex shape of the mold603is transferred to the lens material602dropped on the protective substrate18. At that time, an abutting section611of the mold603which is a protruding part closest to the protective substrate18abuts the protective substrate18, so that a distance between (a height from) the mounting section604and (to) the protective substrate18is controlled with high accuracy. Similarly to the dropping position of the lens material602, the position of the mold603in the planar direction is controlled with high accuracy with respect to an alignment mark formed at a predetermined position on the protective substrate18. The surface of the mold603that comes into contact with the lens material602may be subjected to a mold release treatment in advance so that it can be easily separated from the cured lens material602.

Finally, as shown inFIG.30D, the lens material602is irradiated with ultraviolet light from above the mounting section604in a state where the mold603is pressed against the lens material602, by which the lens material602is cured. Thus, the lens resin part19is formed. The mold603and the mounting section604include a light transmissive material. A light-shielding film (mask)612that does not transmit ultraviolet light is formed on the outer peripheral portion of the mold603in the planar direction, and the lens material602protruding from the abutting section611is not irradiated with ultraviolet light. Therefore, the lens material602outside the abutting section611can be removed without being cured.

Note that a thermosetting resin material may be used as the lens material602in place of an ultraviolet light curable resin material.

FIG.31shows a cross-sectional view of a plane passing through the abutting section611of the mold603and a plan view (bottom view) of a lower surface which is a surface pressed against the lens material602.

The mold603includes four abutting sections611, and each of the four abutting sections611is disposed inside the outer peripheral portion in plan view. Each abutting section611is a columnar body having a cylindrical shape. In the present specification, the columnar body indicates a column or a cone having a surface substantially parallel to an abutting direction as a side surface. The side surface does not need to be perpendicular to the protective substrate18which is an abutment surface, and may be inclined at a predetermined angle. The abutting section611may also be a columnar body having a shape of a prism such as a triangular prism or a quadrangular prism. Furthermore, the abutting section611may also be a columnar body having a shape of a polygonal pyramid such as a triangular pyramid or a quadrangular pyramid, or a conical shape.

Furthermore, a tip of the columnar body which abuts the protective substrate18may have any shape. In the example inFIG.31, a contact surface where the abutting section611contacts the protective substrate18when the mold603is pressed against the protective substrate18has a circular shape as indicated in gray in the bottom view. However, the tip of the abutting section611may have a shape allowing the abutting section611to come in point contact with the protective substrate18as will be described later with reference toFIGS.35A and35B.

Furthermore, in the present embodiment, the four abutting sections611are arranged symmetrically with respect to the center of a planar region of the mold603, but they are not necessarily arranged symmetrically. However, considering the flow of the lens material602described later, they are preferably arranged symmetrically.

It is only sufficient that the abutting sections611can control the plane for controlling the height of the cured lens resin part19, and therefore, it is only required that the number of abutting sections611formed on the mold603is three or more without being limited to four.

The light-shielding film612is formed on an outer peripheral portion outside the four abutting sections611as indicated by a hatched area in the bottom view.

FIG.32is a plan view of the lens resin part19after an excessive lens material602is removed after the curing treatment.

In the region of the light-shielding film612shown inFIG.31, the lens material602is removed without being cured, so that the planar shape of the lens resin part19is rectangle as shown inFIG.32. The lens material602is not present in four regions621respectively corresponding to the four abutting sections611of the mold603.

Note that, in a case where the light-shielding film612formed on the mold603is formed up to an inner side of the four abutting sections611, the lens resin part19has a planar shape which is rectangle as indicated by a broken line19′, and traces of the four regions621respectively corresponding to the abutting sections611do not remain.

In the plan views inFIGS.31and32, a lens part19L at the center indicates a region which exhibits a lens function of refracting the incident light and allowing the same to enter the pixels of the upper structure11in the cured lens resin part19.

<12. Operation and Effect of Mold>

In the mold603used in the lens formation method inFIGS.30A,30B,30C, and30D, a space is formed for allowing the lens material602to flow toward the outside in a state in which the abutting sections611abut the protective substrate18.

Further, the space generated between the mold603and the protective substrate18with the abutting sections611abutting against the protective substrate18allows the lens material602to flow therein from the outside in a case where cure shrinkage of the lens material602occurs.

An energy-curable resin material cured by energy such as ultraviolet light or heat shrinks when being cured. According to the structure of the mold603described above, when the lens material602shrinks, the lens material602protruding outside is supplied from a gap between the mold603and the protective substrate18other than the abutting sections611, so that no wrinkle or void is generated in the lens part19L which exhibits the lens function, as shown inFIGS.33A and33B.

In comparison, a case where the lens shape is imprinted using a mold640which includes an abutting section641having a rectangular shape surrounding an entire circumference as shown inFIGS.34A and34Bis considered, for example. The abutting section641of the mold640is in contact with the protective substrate18on the entire circumference as indicated in gray inFIG.34B. In a case where the lens material602is cured by using such mold640and the lens material602shrinks, the lens material602is not supplied from outside the abutting section641, and the inner lens material602sealed by the abutting section641shrinks, so that voids and wrinkles due to peeling occur.

Therefore, by imprinting using the mold603according to the present disclosure, the space for allowing the resin material to flow toward the outside or flow therein from the outside is formed, so that occurrence of wrinkles and voids can be prevented.

Furthermore, a distance between the abutting sections611of the mold603and the protective substrate18in a height direction is controlled in a plane with high accuracy, so that it is possible to control the lens thickness and shape of the lens resin part19with high accuracy only by pressing the mold603against the protective substrate18.

Therefore, by imprinting using the mold603provided with the abutting sections611, it is possible to form the lens resin part19at low cost while controlling the lens shape with high accuracy with a simple device configuration.

The tips of the abutting sections611of the mold603described above have a cylindrical shape, and when the mold603is pressed against the protective substrate18, the abutting sections611come in circular (surface) contact with the protective substrate18.

On the other hand, in a first modification of the mold603shown inFIG.35A, the tips of the abutting sections611have a substantially spherical (hemispherical) shape. When the mold603according to the first modification is pressed against the protective substrate18, the abutting sections611come in point contact with the protective substrate18.

Further, in a second modification of the mold603shown inFIG.35B, the tips of the abutting sections611have a shape of a polygonal pyramid such as a triangular pyramid. When the mold603according to the second modification is pressed against the protective substrate18, the abutting sections611come in point contact with the protective substrate18. Note that the tips may have a conical shape in place of the polygonal pyramid shape.

As described above, the tips of the abutting sections611may have a shape that comes in point contact with the protective substrate18.

Further, as shown inFIG.35C, the three or more abutting sections611of the mold603may be provided not for each lens but for two or more lenses.

<14. Another Embodiment of Mold>

Next, another embodiment of the mold603will be described.

A mold603shown inFIG.36includes abutting sections661in place of the abutting sections611of the mold603shown inFIG.31, and a light shielding film662in place of the light-shielding film612of the mold603shown inFIG.31.

The abutting sections661are configured to abut against a surface different from the surface of a substrate651on which the lens resin part19is to be formed.

InFIG.36, the substrate651on which the lens resin part19is to be formed has a cavity shape, and has a surface different in height from the surface on which the lens resin part19is to be formed. The abutting sections661of the mold603are provided on the outer peripheral portion of the mold603, and are configured to abut against the upper surface higher than the surface on which the lens resin part19is to be formed. The abutting sections661control the height of the lens resin part19by abutting against the upper surface different from the surface on which the lens resin part19is to be formed.

When the abutting sections661abut against the upper surface on the higher side of the substrate651, a space in which the lens material602can flow can be formed between the lower surface on the lower side of the substrate651having a cavity shape and the mold603. The space allows extra lens material602to release to the outside or allows the lens material602to return to the inside when cure shrinkage occurs.

FIG.37shows a cross-sectional view of the mold603shown inFIG.36and a plan view (bottom view) of a lower surface which is a surface pressed against the lens material602.

In a case where the substrate651(FIG.36) has a difference in height between the surface on which the lens resin part19is to be formed and a surface of a different height, it is possible to align the mold603and the substrate651in the planar direction by using an inclined surface connecting the surfaces.

As shown in the cross-sectional view and the plan view ofFIG.37, the mold603shown inFIG.36is provided with guide sections671with tapered shapes formed so as to be in contact with the inclined surfaces at four corners of the substrate651, and the guide sections671are guided by the inclined surfaces of the cavity shape of the substrate651, so that the position of the mold603in the planar direction is controlled. Except for the four corners of the guide sections671of the mold603, the mold603is recessed more inwardly (in the direction to the lens part19L) than the inclined surfaces of the cavity shape of the substrate651such that a void as a flow path of the lens material602is formed.

<15. Detailed Structure of Solid-State Imaging Element>

Next, the detailed structure and manufacturing method of the solid-state imaging element13of the camera package1will be described.

FIG.38is a diagram showing a detailed cross-sectional structure of the solid-state imaging element13. InFIG.38, the lens resin part19of the camera package1is not shown.

The pixel array unit24is provided in the region of the camera package1including the upper structure11and the portion above the upper structure11. The pixel array unit24includes a plurality of pixels31(FIG.2) which is arrayed, each pixel having the on-chip lens16, the color filter15, the pixel transistor, and the photodiode51. Pixel transistor regions301are also formed in the region (pixel array region) of the pixel array unit24. In the pixel transistor region301, at least one pixel transistor among a transfer transistor, an amplification transistor, and a reset transistor is formed.

A plurality of external terminals14is arranged in a region on the lower surface of the semiconductor substrate81provided in the lower structure12and below the pixel array unit24provided in the upper structure11.

Note that, in the description with reference toFIG.38, the “region on the lower surface of the semiconductor substrate81provided in the lower structure12and below the pixel array unit24provided in the upper structure11” is referred to as a first specific region, and the “region on the upper surface of the semiconductor substrate81provided in the lower structure12and below the pixel array unit24provided in the upper structure11” is referred to as a second specific region.

At least a part of the plurality of external terminals14arranged in the first specific region is used as a signal input terminal14A for inputting a signal from the outside to the camera package1or a signal output terminal14B for outputting a signal from the camera package1to the outside. In other words, the signal input terminal14A and the signal output terminal14B are external terminals14excluding a power supply terminal and a ground terminal from the external terminals14. In the present disclosure, the signal input terminal14A and signal output terminal14B are referred to as signal input/output terminals14C.

Through vias88passing through the semiconductor substrate81are formed in the first specific region and in the vicinity of the signal input/output terminals14C. Note that, in the present disclosure, a through via hole which passes through the semiconductor substrate81and via wiring formed therein may be simply collectively referred to as the through via88.

This through via hole desirably has a structure formed by etching the lower surface of the semiconductor substrate81to a conductive pad322(hereinafter sometimes referred to as a via pad322) which is a part of a multilayer wiring layer82formed above the upper surface of the semiconductor substrate81and which constitutes a terminal end (bottom) of the via hole.

The signal input/output terminal14C disposed in the first specific region is electrically connected to the through via88(more specifically, the via wiring formed in the through via hole) also disposed in the first specific region.

The input/output circuit unit49provided with the input circuit unit42or the output circuit unit47is disposed in the second specific region and in a region in the vicinity of the signal input/output terminal14C and the abovementioned through via.

The signal input/output terminal14C disposed in the first specific region is electrically connected to the input/output circuit unit49via the through via88and the via pad322, or a part of the multilayer wiring layer82.

A region in which the input/output circuit unit49is disposed is referred to as an input/output circuit region311. A signal processing circuit region312is formed adjacent to the input/output circuit region311on the upper surface of the semiconductor substrate81provided in the lower structure12. In the signal processing circuit region312, the image signal processor26described with reference toFIG.2is formed.

A region in which the pixel peripheral circuit unit including all or a part of the row drive unit22and the column signal processor25described with reference toFIG.2is disposed is referred to as a pixel peripheral circuit region313. The pixel peripheral circuit region313is located in a region outside the pixel array unit24on a lower surface of a semiconductor substrate101provided on the upper structure11and the upper surface of the semiconductor substrate81provided on the lower structure12.

The signal input/output terminal14C may be provided in a region under the input/output circuit region311located on the lower structure12, or may be provided in a region under the signal processing circuit region312. Alternatively, the signal input/output terminal14C may be provided below the pixel peripheral circuit unit, such as the row drive unit22or the column signal processor25, which is disposed in the lower structure12.

In the present disclosure, a wiring connecting structure which connects wiring included in a multilayer wiring layer102of the upper structure11and wiring included in the multilayer wiring layer82of the lower structure12is sometimes referred to as an upper/lower wiring connecting structure, and a region in which the structure is disposed is sometimes referred to as an upper/lower wiring connecting region314.

The upper/lower wiring connecting structure includes a first through electrode (silicon through electrode)109which passes through the semiconductor substrate101from the upper surface of the upper structure11and reaches the multilayer wiring layer102, a second through electrode (chip through electrode)105which passes through the semiconductor substrate101and the multilayer wiring layer102from the upper surface of the upper structure11and reaches the multilayer wiring layer82of the lower structure12, and a connecting wiring106for connecting the two through electrodes (through silicon via, TSV). In the present disclosure, such an upper/lower wiring connecting structure is sometimes referred to as a twin contact structure.

The upper/lower wiring connecting region314is located outside the pixel peripheral circuit region313.

In the present embodiment, the pixel peripheral circuit region313is formed in both the upper structure11and the lower structure12, but it may be formed in only one of them.

Furthermore, in the present embodiment, the upper/lower wiring connecting region314is located outside the pixel array unit24and outside the pixel peripheral circuit region313, but it may also be located outside the pixel array unit24and inside the pixel peripheral circuit region313.

Moreover, the present embodiment employs, as a structure for electrically connecting the multilayer wiring layer102of the upper structure11and the multilayer wiring layer82of the lower structure12, the twin contact structure for connecting them by using the two through electrodes, the silicon through electrode109and the chip through electrode105.

As a structure for electrically connecting the multilayer wiring layer102of the upper structure11and the multilayer wiring layer82of the lower structure12, a share contact structure may be used, for example, in which each of a wiring layer103of the upper structure11and a wiring layer83of the lower structure12is commonly connected to one through electrode.

<16. Method for Manufacturing Camera Package>

Next, a method for manufacturing the camera package1will be described with reference toFIGS.39to53.

First, the lower structure12and the upper structure11which are in the form of wafer are manufactured separately.

As the lower structure12, the multilayer wiring layer82which serves as the input/output circuit unit49and a part of the row drive unit22or the column signal processor25is formed in a region where each chip unit of the semiconductor substrate81is to be formed. The semiconductor substrate81at that time is not yet thinned, and has a thickness of, for example, about 600 μm.

In contrast, as the upper structure11, photodiodes51and source/drain regions of pixel transistors of the respective pixels31are formed in a region where each chip unit of the semiconductor substrate101is to be formed. Further, the multilayer wiring layer102that constitutes the row drive signal lines32, vertical signal lines33, and the like is formed on one surface of the semiconductor substrate101. The semiconductor substrate101at that time is also not yet thinned, and has a thickness of, for example, about 600 μm.

Then, the lower structure12and the upper structure11which are thus manufactured and which are in the form of wafer are bonded to each other with the multilayer wiring layer82side facing the multilayer wiring layer102side as shown inFIG.39, and then, the semiconductor substrate101of the upper structure11is thinned as shown inFIG.40. The bonding may be performed using, for example, plasma bonding or bonding with an adhesive, and in the present embodiment, plasma bonding is used. In the case of plasma bonding, a film such as a plasma TEOS film, a plasma SiN film, a SiON film (block film), or a SiC film is formed on bonding surfaces of the upper structure11and the lower structure12, respectively. The bonding surfaces are subjected to a plasma treatment, overlapped with each other, and then, subjected to annealing. Thus, they are bonded to each other.

After the semiconductor substrate101of the upper structure11is thinned, the silicon through electrode109, the chip through electrode105, and the connecting wiring106for connecting them are formed in a region which is to be the upper/lower wiring connecting region314using a damascene method and the like, as shown inFIG.41.

Next, as shown inFIG.42, the color filter15and the on-chip lens16are formed on the photodiode51of each pixel31via a flattening film108.

Then, the sealing resin17is applied to the entire surface, on which the on-chip lenses16are provided, of the solid-state imaging element13obtained by bonding the upper structure11and the lower structure12via a flattening film110as shown inFIG.43, and the protective substrate18is bonded with a cavityless structure as shown inFIG.44.

In this case, in a case where the method in which the lens resin part19is formed on the protective substrate18, and then, the resultant is bonded to the solid-state imaging element13as described with reference toFIG.18Bis used, the lens resin part19is already formed on the protective substrate18.

On the other hand, in a case where the method in which the lens resin part19is formed on the protective substrate18after the protective substrate18is placed on the solid-state imaging element13as described with reference toFIG.18Ais used, the lens resin part19is formed on the protective substrate18in a predetermined step after the state shown inFIG.44is obtained.

Next, as shown inFIG.45, after the entire solid-state imaging element13is inverted, the semiconductor substrate81of the lower structure12is thinned to a thickness that does not affect the device characteristics, for example, about 30 μm to 100 μm.

Next, as shown inFIG.46, a photoresist221is patterned so that the position where the through via88(not shown) is formed on the thinned semiconductor substrate81is opened, and then, the semiconductor substrate81and a part of an interlayer insulating film84are removed by dry etching, and an opening222is formed.

Next, as shown inFIG.47, an insulating film (isolation film)86is formed on the entire upper surface of the semiconductor substrate81including the opening222by, for example, a plasma CVD method. The insulating film86can be, for example, a SiO2 film or a SiN film.

Next, as shown inFIG.48, the insulating film86on the bottom surface of the opening222is removed using an etchback process, by which the wiring layer83cclosest to the semiconductor substrate81is exposed.

Next, as shown inFIG.49, a barrier metal film (not shown) and a Cu seed layer231are formed using a sputtering method. The barrier metal film is for preventing diffusion of a connection conductor87(Cu) shown inFIG.50, and the Cu seed layer231serves as an electrode when the connection conductor87is embedded with an electrolytic plating method. As the material of the barrier metal film, tantalum (Ta), titanium (Ti), tungsten (W), zirconium (Zr), a nitride film thereof, a carbonized film thereof, and the like can be used. In the present embodiment, titanium is used as the barrier metal film.

Next, as shown inFIG.50, after a resist pattern241is formed in a required region on the Cu seed layer231, copper (Cu) as the connection conductor87is plated using the electrolytic plating method. As a result, the through via88is formed, and rewiring90is also formed above the semiconductor substrate81.

Next, as shown inFIG.51, after the resist pattern241is removed, the barrier metal film (not shown) and the Cu seed layer231under the resist pattern241are removed by wet etching.

Next, as shown inFIG.52, a solder mask91is formed to protect the rewiring90, and then, the solder mask91only in a region where the external terminals14are mounted is removed, by which a solder mask opening242is formed.

Then, as shown inFIG.53, the external terminal14is formed in the solder mask opening242by a solder ball mounting method or the like.

As described above, according to the method for manufacturing the solid-state imaging element13, first, the upper structure11(first semiconductor substrate) on which the photodiodes51for photoelectric conversion, the pixel transistor circuit, and the like are formed, and the lower structure12(second semiconductor substrate) in which the input/output circuit unit49for outputting the pixel signal output from the pixel31to the outside of the camera package1is located below the pixel array unit24are bonded to each other with the wiring layers facing each other. Then, the through via88which passes through the lower structure12is formed, and the external terminal14electrically connected to the outside of the camera package1via the input/output circuit unit49and the through via88is formed. In this way, the camera package1shown inFIG.1can be manufactured.

<17. Configuration Example of Camera Module>

A mold to which the present disclosure is applied can be used for forming a mold in a wafer-level lens process for simultaneously forming a plurality of lenses in a planar direction of a wafer substrate by imprinting.

In the following, a configuration of a camera module formed by using the wafer-level lens process for simultaneously forming a plurality of lenses in the planar direction of the wafer substrate will be described first, and a specific step in which the mold according to the present disclosure can be used in the process for forming the camera module will be described next.

FIG.54is a cross-sectional view of a camera module700.

The camera module700includes a multilayer lens structure (lens module)702in which a plurality of lens-equipped substrates701ato701eis stacked. The multilayer lens structure702constitutes one optical unit703. A dash-dot-dash line704represents an optical axis of the optical unit703.

The camera package1shown inFIG.1is disposed under the multilayer lens structure702. The camera package1is fixed to the multilayer lens structure702via a structural material740formed using, for example, an epoxy resin.

In the camera module700, light entering the camera module700from above passes through the multilayer lens structure702and enters the on-chip lenses16, the color filter15, and photoelectric conversion elements such as photodiodes (not shown) formed on the upper structure11of the camera package1.

The multilayer lens structure702includes five lens-equipped substrates701ato701ewhich are stacked. In a case where the five lens-equipped substrates701ato701eare not particularly distinguished, they are simply referred to as the lens-equipped substrates701.

Note that, although the multilayer lens structure702includes five lens-equipped substrates701ato701ein the example inFIG.54, the number of lens-equipped substrates701to be stacked may be two or more except for five, or may be one.

Each of the lens-equipped substrates701constituting the multilayer lens structure702has a configuration in which a lens resin part722is added to a carrier substrate721. The carrier substrate721has a through hole723, and the lens resin part722is formed inside the through hole723. The lens resin part722indicates a portion in which a lens part and a part that extends to the carrier substrate721and that supports the lens part are integrated by the material constituting the lens part.

Note that, in a case where the carrier substrates721, the lens resin parts722, or the through holes723of the lens-equipped substrates701ato701eare distinguished from each other, they are referred to as carrier substrates721ato81e, lens resin parts722ato82e, or through-holes723ato83ecorresponding to the lens-equipped substrates701ato41eas shown inFIG.54.

The through hole723of each of the lens-equipped substrates701constituting the multilayer lens structure702has a cross section with a so-called funnel shape in which an opening width decreases toward the bottom.

A diaphragm plate731is disposed on the multilayer lens structure702. The diaphragm plate731has, for example, a layer including a material having optical absorption property or light shielding property. The diaphragm plate731is provided with an opening732.

The multilayer lens structure702, the camera package1, the diaphragm plate731, etc. are housed in a lens barrel751.

As described above, the camera package1shown inFIG.1can constitute the camera module700in combination with the multilayer lens structure702in which a plurality of lens-equipped substrates701is stacked.

Further, the camera module700can be constructed by combining the camera package1shown inFIG.22and the multilayer lens structure702as shown inFIG.55, or by combining the camera package1shown inFIG.29and the multilayer lens structure702.

Moreover, as shown inFIG.56, the camera module700may be configured as a compound eye camera module in which the multilayer lens structure702is provided with a plurality of optical units703, and the camera package1is also provided with a plurality of light receiving regions corresponding to the plurality of optical units703.

Note that the camera package1of the camera module700shown inFIG.56employs a configuration in which the sealing resin17embedded between the on-chip lens16and the protective substrate18and the lens resin part19and the high contact angle film20formed on the upper surface of the protective substrate18are omitted.

In the example ofFIG.56, the plurality of optical units703formed in the multilayer lens structure702has the same configuration, but may have different configurations. That is, the plurality of optical units703may have different optical parameters due to a difference in shape and number among the lens resin parts722. For example, the plurality of optical units703may include an optical unit703having a short focal length for imaging a near view and an optical unit703having a long focal length for imaging a distant view.

FIGS.57A,57B,57C,57D,57E, and57Fare diagrams for describing a manufacturing method for manufacturing the multilayer lens structure702described with reference toFIGS.54to56in a form of substrate.

First, as shown inFIG.57A, a lens-equipped substrate701W-e which is in a form of substrate and which is located in the lowermost layer in the multilayer lens structure702is prepared. Note that the lens-equipped substrate701W-e refers to a lens-equipped substrate in a form of substrate (wafer) before being diced into lens-equipped substrates701e. Similarly, later-described lens-equipped substrates701W-a to701W-d in a form of substrate refer to lens-equipped substrates in a form of substrate (wafer) before being diced into lens-equipped substrates701ato701e.

Next, as shown inFIG.57B, the lens-equipped substrate701W-d in a form of substrate located in the second lowest layer in the multilayer lens structure702is bonded on the lens-equipped substrate701W-e in a form of substrate.

Next, as shown inFIG.57C, the lens-equipped substrate701W-c in a form of substrate located in the third lowest layer in the multilayer lens structure702is bonded on the lens-equipped substrate701W-d in a form of substrate.

Next, as shown inFIG.57D, the lens-equipped substrate701W-b in a form of substrate located in the fourth lowest layer in the multilayer lens structure702is bonded on the lens-equipped substrate701W-c in a form of substrate.

Next, as shown inFIG.57E, the lens-equipped substrate701W-a in a form of substrate located in the fifth lowest layer in the multilayer lens structure702is bonded on the lens-equipped substrate701W-b in a form of substrate.

Finally, as shown inFIG.57E, the diaphragm plate731W located on the lens-equipped substrate701ain the multilayer lens structure702is bonded onto the lens-equipped substrate701W-a in a form of substrate. The diaphragm plate731W refers to a diaphragm plate in a form of substrate (wafer) before being diced into diaphragm plates731.

As described above, the five lens-equipped substrates701W-a to701W-e in a form of substrate are sequentially stacked one by one from the lens-equipped substrate701W in the lower layer to the lens-equipped substrate701W in the upper layer in the multilayer lens structure702, so that the multilayer lens structure702W in a form of substrate is obtained.

Note that it is also possible to form the multilayer lens structure702W in a form of substrate by sequentially stacking the lens-equipped substrates one by one from the lens-equipped substrate701W in the upper layer to the lens-equipped substrate701W in the lower layer.

FIGS.58A and58Bare diagrams for describing bonding between the lens-equipped substrate701W-a in a form of substrate and the lens-equipped substrate701W-b in a form of substrate as an example of bonding two lens-equipped substrates701W in a form of substrate.

Note that, in the description with reference toFIGS.58A and58B, portions of the lens-equipped substrate701W-b corresponding to those of the lens-equipped substrate701W-a are designated by the same reference numerals as the lens-equipped substrate701W-a.

An upper surface layer801is formed on the upper surface of each of the lens-equipped substrate701W-a and the lens-equipped substrate701W-b. A lower surface layer802is formed on the lower surface of each of the lens-equipped substrate701W-a and the lens-equipped substrate701W-b. Then, as shown inFIG.58A, a plasma activation treatment is performed on the surfaces of the lens-equipped substrates701W-a and701W-b which are to be bonded to each other, that is, on the entire lower surface of the lens-equipped substrate701W-a including a back flat part812and the entire upper surface of the lens-equipped substrate701W-b including a front flat part811. Any kind of gas capable of plasma treatment such as O2, N2, He, Ar, or H2 may be used as a gas used for the plasma activation treatment. Note that it is preferable to use a gas same as the constituent element of the upper surface layer801and the lower surface layer802as the gas used for the plasma activation treatment, because using such gas can suppress alteration of films of the upper surface layer801and the lower surface layer802.

Then, as shown inFIG.58B, the back flat part812of the lens-equipped substrate701W-a and the front flat part811of the lens-equipped substrate701W-b which have activated surfaces are bonded to each other.

Due to the process of bonding the lens-equipped substrates described above, a hydrogen bond is formed between hydrogen of an OH group on the surface of the lower surface layer802of the lens-equipped substrate701W-a and hydrogen of an OH group on the surface of the upper surface layer801of the lens-equipped substrate701W-b. As a result, the lens-equipped substrates701W-a and701W-b are fixed. The process of bonding the lens-equipped substrates described above can be performed under atmospheric pressure conditions.

The lens-equipped substrates701W-a and701W-b that have undergone the abovementioned bonding process are annealed. As a result, dehydration condensation occurs in the state where the OH groups are bonded by hydrogen bonding, and a covalent bond through oxygen is formed between the lower surface layer802of the lens-equipped substrate701W-a and the upper surface layer801of the lens-equipped substrate701W-b. Alternatively, an element contained in the lower surface layer802of the lens-equipped substrate701W-a and an element contained in the upper surface layer801of the lens-equipped substrate701W-b are covalently bonded. Due to the bonding described above, the two lens-equipped substrates are firmly fixed. The state where the two lens-equipped substrates701W are fixed by a covalent bond formed between the lower surface layer802of the upper lens-equipped substrate701W and the upper surface layer801of the lower lens-equipped substrate701W as described above is referred to as direct bonding in the present specification. The direct bonding according to the present disclosure does not use resin for fixing multiple lens-equipped substrates701W, and thus, can provide an operation or effect that the multiple lens-equipped substrates701W can be fixed without causing cure shrinkage or thermal expansion which may be caused when resin is used.

The annealing treatment mentioned above can also be performed under atmospheric pressure conditions. In order to cause dehydration condensation, the annealing treatment may be performed at 100° C. or higher, 150° C. or higher, or 200° C. or higher. On the other hand, the annealing treatment may be performed at 400° C. or less, 350° C. or less, or 300° C. or less from the viewpoint of protecting an energy-curable resin for forming the lens resin part722from heat and suppressing degassing from the energy-curable resin.

Suppose that the abovementioned process of bonding the lens-equipped substrates701W or the abovementioned direct bonding process of bonding the lens-equipped substrates701W is performed under a condition other than the atmospheric pressure condition. When the lens-equipped substrates701W-a and701W-b which are bonded to each other are returned to an environment with atmospheric pressure, a pressure difference occurs between the outside of the lens resin parts722and the space between the lens resin parts722which are bonded to each other. Due to this pressure difference, pressure is applied to the lens resin parts722, so that the lens resin parts722may be likely to deform.

Performing both the abovementioned bonding process of bonding the lens-equipped substrates701W and the abovementioned direct bonding process of bonding the lens-equipped substrates701W under atmospheric pressure condition provides an operation or effect capable of preventing deformation of the lens resin parts722which may be likely to occur when the bonding is performed under a condition other than atmospheric pressure.

By directly bonding the plasma-activated substrates, in other words, by bonding the substrates by plasma, it is possible to suppress fluidity and thermal expansion which may occur when, for example, a resin is used as an adhesive, whereby positional accuracy during bonding between the lens-equipped substrates701W-a and701W-b can be enhanced.

As described above, the upper surface layer801or the lower surface layer802is formed on the back flat part812of the lens-equipped substrate701W-a and the front flat part811of the lens-equipped substrate701W-b. Dangling bonds are easily formed in the upper surface layer801and the lower surface layer802by the plasma activation treatment performed earlier. That is, the lower surface layer802formed on the back flat part812of the lens-equipped substrate701W-a and the upper surface layer801formed on the front flat part811of the lens-equipped substrate701W-b have a function of increasing the bonding strength.

Further, in a case where the upper surface layer801or the lower surface layer802includes an oxide film, they are not affected by a change in film quality due to plasma (O2). Therefore, this configuration also provides an effect of suppressing corrosion of the lens resin part722due to plasma.

As described above, the lens-equipped substrate701W-a in a form of substrate having multiple lens-equipped substrates701aformed thereon and the lens-equipped substrate701W—in a form of substrate having multiple lens-equipped substrates701bformed thereon are directly bonded after being subjected to a surface activation treatment using plasma, in other words, are bonded using plasma bonding.

The similar method is also applied to bond another two lens-equipped substrates701W in a form of substrate.

Next, a method for manufacturing the lens-equipped substrate701W in a form of substrate will be described with reference toFIGS.59A,59B,59C,59D,59E,59F, and59G.

First, as shown inFIG.59A, a carrier substrate721W having a plurality of through holes723is prepared. A light-shielding film911for preventing reflection of light is formed on the side wall of each of the through holes723. AlthoughFIGS.59A,59B,59C,59D,59E,59F, and59Gshow only two through holes723due to space limitation, a large number of through holes723are actually formed in the carrier substrate721W in a planar direction. Further, an alignment mark (not shown) for positional alignment is formed in a region near the outer periphery of the carrier substrate721W.

A front flat part811on the upper side of the carrier substrate721W and a back flat part812on the lower side are flat surfaces that is flat enough to be bonded by plasma bonding as described above. The thickness of the carrier substrate721W serves as a spacer for determining the distance between lenses when the carrier substrate721W is finally diced into lens-equipped substrates701and the obtained lens-equipped substrate701is stacked on another lens-equipped substrate701.

It is preferable to use a base material having a low thermal expansion coefficient of 10 ppm/° C. or less for the carrier substrate721W.

Next, as shown inFIG.59B, the carrier substrate721W is placed on a mold substrate921in which a plurality of concave molds922is arranged at regular intervals. More specifically, the back flat part812of the carrier substrate721W and a flat surface923of the mold substrate921are overlapped so that the concave molds922are located inside the through holes723of the carrier substrate721W. The molds922of the mold substrate921are formed so as to correspond one-to-one with the through holes723of the carrier substrate721W, and the position of the carrier substrate721W and the position of the mold substrate921in the planar direction are adjusted so that the center of the mold922and the center of the corresponding through hole723coincide with each other along the optical axis direction. The mold substrate921is constructed using a hard mold material such as metal, silicon, quartz, or glass, for example.

Next, as shown inFIG.59C, an energy-curable resin931is filled (dropped) inside the through holes723of the carrier substrate721W and the mold substrate921which are overlapped with each other. The lens resin parts722are formed by using the energy-curable resin931. Therefore, the energy-curable resin931is preferably defoamed in advance so as not to contain air bubbles. A vacuum defoaming process or a defoaming process using centrifugal force is preferably used as the defoaming process. Further, the vacuum defoaming process is preferably performed after filling. By performing the defoaming process, the lens resin parts722can be molded without entraining air bubbles.

Next, as shown inFIG.59D, a mold substrate941is placed above the overlapped mold substrate921and the carrier substrate721W. A plurality of concave molds942is provided on the mold substrate941at regular intervals, and the mold substrate941is placed after being positioned with high accuracy so that the center of the through hole723and the center of the corresponding mold942coincide with each other along the optical axis direction in a manner similar to the manner of placing the mold substrate921. The mold substrate941is constructed using a hard mold material such as metal, silicon, quartz, or glass, for example.

Regarding the height direction which is the vertical direction of the page, the position of the mold substrate941is fixed such that a distance between the mold substrate941and the mold substrate921is adjusted to a predetermined distance by a control device which controls the distance between the mold substrate941and the mold substrate921. During this process, the space between the mold942of the mold substrate941and the mold922of the mold substrate921is equal to the thickness of the lens resin part722calculated by optical design.

Alternatively, as shown inFIG.59E, a flat surface943of the mold substrate941and the front flat part811of the carrier substrate721W may be overlapped as in the case where the mold substrate921is placed. In this case, the distance between the mold substrate941and the mold substrate921is the same as the thickness of the carrier substrate721W, and highly accurate alignment in the planar direction and the height direction can be achieved.

When the distance between the mold substrate941and the mold substrate921is controlled to be a preset distance, the energy-curable resin931is dropped and added inside of the through hole723of the carrier substrate721W in an amount controlled so as to prevent the energy-curable resin931from overflowing from the space enclosed by the through hole723of the carrier substrate721W and the mold substrate941and the mold substrate921above and below the carrier substrate721W in the step shown inFIG.59C. As a result, the manufacturing cost can be reduced without wasting the material of the energy-curable resin931.

Subsequently, the energy-curable resin931is cured in the state shown inFIG.59E. The energy-curable resin931is cured by, for example, applying heat or UV light as energy and being left to stand for a predetermined time. The amount of deformation of the energy-curable resin931due to shrinkage can be minimized by pushing the mold substrate941downward or performing alignment during curing.

A thermoplastic resin may be used instead of the energy-curable resin931. In that case, in the state shown inFIG.59E, the energy-curable resin931is formed into a lens shape by raising the temperature of the mold substrate941and the mold substrate921, and is cured by cooling.

Next, as shown inFIG.59E, the control device that controls the positions of the mold substrate941and the mold substrate921moves the mold substrate941upward and the mold substrate921downward, thereby releasing the mold substrate941and the mold substrate921from the carrier substrate721W. When the mold substrate941and the mold substrate921are released from the carrier substrate721W, the lens resin part722is formed inside the through hole723of the carrier substrate721W.

Note that the surfaces of the mold substrate941and the mold substrate921which come into contact with the carrier substrate721W may be coated with a release agent such as a fluorine-based or silicon-based release agent, for example. By doing so, the carrier substrate721W can be easily released from the mold substrate941and the mold substrate921. Further, as a method of easily releasing the mold from the contact surface with the carrier substrate721W, various coatings such as fluorine-containing diamond like carbon (DLC) may be applied.

Next, as shown inFIG.59G, the upper surface layer801is formed on the surfaces of the carrier substrate721W and the lens resin part722, and the lower surface layer802is formed on the back surfaces of the carrier substrate721W and the lens resin part722. The front flat part811and the back flat part812of the carrier substrate721W may be flattened by performing, as necessary, chemical mechanical polishing (CMP) and the like before or after the upper surface layer801and the lower surface layer802are formed.

As described above, the lens resin parts722are formed by imprinting (press-molding) the energy-curable resin931in the through holes723formed in the carrier substrate721W using the mold substrate941and the mold substrate921, whereby the lens-equipped substrate701W in a form of substrate can be manufactured.

The shapes of the mold922and the mold942are not limited to the concave shape described above, and are determined, as appropriate, depending on the shape of the lens resin part722. As shown inFIGS.54to56, the lenses of the lens-equipped substrates701ato701emay have various shapes derived by optical system design, for example, may have a biconvex shape, a biconcave shape, a planoconvex shape, a plano-concave shape, a convex meniscus shape, a concave meniscus shape, and further a higher-order aspherical shape.

Further, the shapes of the mold922and the mold942may be such that the formed lens shape has a moth-eye structure.

According to the manufacturing method described above, a variation in distance in the planar direction between the lens resin parts722due to cure shrinkage of the energy-curable resin931can be eliminated by intervention of the carrier substrate721W, so that the distance between lenses can be controlled with high accuracy. Further, the abovementioned manufacturing method provides an effect of reinforcing the energy-curable resin931having low strength with the carrier substrate721W having high strength. This makes it possible to provide a lens array substrate having a plurality of lenses with good handleability formed thereon, and further, provide an effect of suppressing warpage of the lens array substrate.

The method for forming the mold503described with reference toFIGS.28A,28B,28C, and28Dcan be used for forming the mold922and the mold942used in the abovementioned method for manufacturing the lens-equipped substrate701W in a form of substrate.

<20. Example of Application to Electronic Device>

The abovementioned camera package1and camera module700can be mounted in an electronic device using a camera package in an image capturing unit (photoelectric conversion unit) such as: an imaging device such as a digital still camera and a video camera; a portable terminal device having an imaging function; and a copying machine using a camera package in an image reading unit.

FIG.60is a block diagram showing a configuration example of an imaging device that is an electronic device to which the present disclosure is applied.

An imaging device2000inFIG.60includes a camera module2002and a digital signal processor (DSP) circuit2003which is a camera signal processing circuit. The imaging device2000also includes a frame memory2004, a display unit2005, a recording unit2006, an operation unit2007, and a power source unit2008. The DSP circuit2003, the frame memory2004, the display unit2005, the recording unit2006, the operation unit2007, and the power source unit2008are connected to each other via a bus line2009.

An image sensor2001in the camera module2002captures incident light (image light) from a subject, converts an amount of incident light formed into an image on an imaging surface into an electric signal on a pixel-by-pixel basis, and outputs the electric signal as a pixel signal. As the camera module2002, the abovementioned camera module700is employed, and the image sensor2001corresponds to the abovementioned solid-state imaging element13. In a case where the configuration of the camera package1is employed as an imaging unit of the imaging device2000, the camera module2002is replaced with the camera package1.

The display unit2005includes, for example, a panel-type display device such as a liquid crystal panel or an organic electro luminescence (EL) panel, and displays a moving image or a still image captured by the image sensor2001. The recording unit2006records a moving image or a still image captured by the image sensor2001on a recording medium such as a hard disk or a semiconductor memory.

The operation unit2007issues operation commands for various functions of the imaging device2000in response to an operation performed by a user. The power source unit2008appropriately supplies various power supplies, which are operation power supplies for the DSP circuit2003, the frame memory2004, the display unit2005, the recording unit2006, and the operation unit2007, to these power supply targets.

As described above, high image quality and miniaturization can be achieved by using the camera module700equipped with the multilayer lens structure702that is positioned and bonded (stacked) with high accuracy as the camera module2002. Therefore, in the imaging device2000such as a video camera, a digital still camera, and a camera module for mobile devices such as mobile phones, it is also possible to achieve both miniaturization of the semiconductor package and high image quality of the captured image.

<Use Example of Image Sensor>

FIG.61is a diagram showing use examples of an image sensor using the abovementioned camera package1or camera module700.

The image sensor using the camera package1or the camera module700can be used in various cases for sensing light such as visible light, infrared light, ultraviolet light, and X-ray as described below, for example.Devices that capture images used for viewing, such as digital cameras and mobile devices with camera functionsDevices used for traffic such as: in-vehicle sensors that capture an image of an environment in front of, at the rear of, and around automobile, the interior of the automobile, etc. for safe driving such as automatic stop, recognition of the condition of driver, etc.; surveillance cameras that monitor traveling vehicles or road; or distance measurement sensors that measure the distance between vehicles, etc.Devices used in home appliances such as TVs, refrigerators, and air conditioners to capture an image of user's gesture and perform operations according to the gestureDevices used for medical and healthcare, such as endoscopes and devices that perform angiography by receiving infrared lightDevices used for security, such as surveillance cameras for crime prevention and cameras for personal authenticationDevices used for beauty, such as skin measuring devices that capture an image of the skin and microscopes that capture the image of the scalpDevices used for sports such as action cameras and wearable cameras for sporting use, etc.Devices used for agriculture, such as cameras for monitoring the condition of fields and crops
<21. Example of Application to In-Vivo Information Acquisition System>

The technology according to the present disclosure (present technology) can be applied to various products as described above. For example, the technology according to the present disclosure may be applied to an in-vivo information acquisition system for acquiring in-vivo information of a patient using a capsule endoscope.

FIG.62is a block diagram showing an example of a schematic configuration of the in-vivo information acquisition system for acquiring in-vivo information of a patient using a capsule endoscope, to which the technology (the present technology) according to the present disclosure may be applied.

An in-vivo information acquisition system10001includes a capsule endoscope10100and an external control device10200.

The capsule endoscope10100is swallowed by a patient during examination. The capsule endoscope10100has an imaging function and a wireless communication function. The capsule endoscope10100sequentially captures images (hereinafter also referred to as in-vivo images) of the interior of organs such as the stomach and the intestines at predetermined intervals, and sequentially transmits information regarding the in-vivo images to the external control device10200outside the body in a wireless manner, while moving through the interior of the relevant organs by peristaltic movement or the like until being excreted naturally from the patient.

The external control device10200centrally controls the operation of the in-vivo information acquisition system10001. Further, the external control device10200receives information regarding the in-vivo images transmitted from the capsule endoscope10100, and generates image data for displaying the in-vivo images on a display device (not illustrated) on the basis of the received information regarding the in-vivo images.

In this way, with the in-vivo information acquisition system10001, in-vivo images indicating the patient's internal conditions can be obtained continually from the time the capsule endoscope10100is swallowed to the time the capsule endoscope10100is excreted.

The configurations and functions of the capsule endoscope10100and the external control device10200will be described in further detail.

The capsule endoscope10100includes a capsule-shaped housing10101, and includes a light source unit10111, an imaging unit10112, an image processor10113, a wireless communication unit10114, a power supply unit10115, a power source unit10116, and a controller10117which are housed in the capsule-shaped housing10101.

The light source unit10111includes a light source such as a light-emitting diode (LED), for example, and irradiates the imaging field of the imaging unit10112with light.

The imaging unit10112includes an imaging element, and an optical system including multiple lenses provided in front of the imaging element. Reflected light (hereinafter referred to as observation light) of light emitted toward a body tissue which is an observation target is condensed by the optical system and enters the imaging element. The imaging unit10112photoelectrically converts, by the imaging element, the observation light entering the imaging element, and generates an image signal corresponding to the observation light. The image signal generated by the imaging unit10112is provided to the image processor10113.

The image processor10113includes a processor such as a central processing unit (CPU) or a graphics processing unit (GPU), and performs various kinds of signal processing on the image signal generated by the imaging unit10112. The image processor10113provides the image signal subjected to signal processing to the wireless communication unit10114as RAW data.

The wireless communication unit10114performs a predetermined process such as a modulation process on the image signal that has been subjected to signal processing by the image processor10113, and transmits the resultant image signal to the external control device10200via an antenna10114A. In addition, the wireless communication unit10114receives, from the external control device10200, a control signal related to drive control of the capsule endoscope10100via the antenna10114A. The wireless communication unit10114provides the control signal received from the external control device10200to the controller10117.

The power supply unit10115includes an antenna coil for receiving power, a power regeneration circuit for regenerating power from a current produced in the antenna coil, a booster circuit, and the like. In the power supply unit10115, the principle of what is called contactless charging is used to generate power.

The power source unit10116includes a secondary battery, and stores power generated by the power supply unit10115. Although arrows or the like indicating the destination to which power from the power source unit10116is supplied are not illustrated inFIG.62for preventing the illustration from being complex, power stored in the power source unit10116is supplied to the light source unit10111, the imaging unit10112, the image processor10113, the wireless communication unit10114, and the controller10117, and may be used to drive these units.

The controller10117includes a processor such as a CPU, and appropriately controls drives of the light source unit10111, the imaging unit10112, the image processor10113, the wireless communication unit10114, and the power supply unit10115in accordance with a control signal transmitted from the external control device10200.

The external control device10200may be a processor such as a CPU or GPU, or a device such as a microcomputer or a control board on which a processor and a storage element such as a memory are mounted. The external control device10200controls the operation of the capsule endoscope10100by transmitting a control signal to the controller10117of the capsule endoscope10100via an antenna10200A. In the capsule endoscope10100, for example, a light irradiation condition under which the light source unit10111irradiates an observation target with light may be changed by a control signal from the external control device10200. In addition, an imaging condition (such as a frame rate and an exposure level in the imaging unit10112, for example) may be changed by a control signal from the external control device10200. In addition, the content of processing in the image processor10113and a condition (such as a transmission interval and the number of images to transmit, for example) under which the wireless communication unit10114transmits the image signal may be changed by a control signal from the external control device10200.

In addition, the external control device10200performs various types of image processing on the image signal transmitted from the capsule endoscope10100, and generates image data for displaying a captured in-vivo image on the display device. As the image processing, various known signal processing may be performed, such as a development process (demosaicing process), an image quality-improving process (such as a band enhancement process, a super-resolution process, a noise reduction (NR) process, and/or a shake correction process), and/or a scaling process (electronic zoom process). The external control device10200controls the drive of the display device, and causes the display device to display a captured in-vivo image on the basis of the generated image data. Alternatively, the external control device10200may also cause a recording device (not shown) to record the generated image data, or cause a printing device (not shown) to make a printout of the generated image data.

An example of the in-vivo information acquisition system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit10112in the configuration described above. Specifically, the camera package1or the camera module700can be applied as the imaging unit10112. By applying the technology according to the present disclosure to the imaging unit10112, the capsule endoscope10100can be further miniaturized, so that the burden on the patient can be further reduced. In addition, a clearer surgical site image can be obtained with the capsule endoscope10100being reduced in size, whereby the accuracy of examination is improved.

<22. Example of Application to Endoscopic Surgical System>

For example, the technology according to the present disclosure may be applied to an endoscopic surgical system.

FIG.63is a diagram showing an example of a schematic configuration of an endoscopic surgical system to which the technology according to the present disclosure can be applied.

FIG.63illustrates a state in which an operator (surgeon)11131performs surgery on a patient11132on a patient bed11133using an endoscopic surgical system11000. As illustrated, the endoscopic surgical system11000includes an endoscope11100, other surgical instruments11110such as a pneumoperitoneum tube11111and an energy treatment instrument11112, a supporting arm device11120for supporting the endoscope11100, and a cart11200on which various devices for endoscopic surgery are mounted.

The endoscope11100includes a lens tube11101inserted into the body cavity of a patient11132by a predetermined length from a distal end and a camera head11102connected to a proximal end of the lens tube11101. The illustrated example shows that the endoscope11100is a so-called rigid scope having a rigid lens tube11101. However, the endoscope11100may be a so-called flexible scope having a flexible lens tube.

An opening in which an objective lens is fitted is provided at the distal end of the lens tube11101. A light source device11203is connected to the endoscope11100, and light generated by the light source device11203is guided to the distal end of the lens tube by a light guide extending in the lens tube11101and is emitted to a target to be observed in the body cavity of the patient11132through the objective lens. Note that the endoscope11100may be a forward-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

An optical system and an imaging element are provided in the camera head11102, and light reflected by the target to be observed (observation light) is condensed on the imaging element by the optical system. The imaging element photoelectrically converts the observation light and generates an electric signal corresponding to the observation light, that is, an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU)11201as RAW data.

The CCU11201includes a central processing unit (CPU), a graphics processing unit (GPU), and the like, and centrally controls the operations of the endoscope11100and the display device11202. Moreover, the CCU11201receives the image signal from the camera head11102and applies various types of image processing for displaying an image based on the image signal, for example, a development process (demosaicing process) and the like on the image signal.

The display device11202displays the image based on the image signal which has been subjected to the image processing by the CCU11201under the control of the CCU11201.

The light source device11203includes a light source such as a light emitting diode (LED), for example, and supplies irradiation light for imaging a surgical site or the like to the endoscope11100.

An input device11204is an input interface for the endoscopic surgical system11000. A user may input various kinds of information and instructions to the endoscopic surgical system11000via the input device11204. For example, the user inputs an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) by the endoscope11100.

A treatment instrument control device11205controls driving of the energy treatment instrument11112for tissue cauterization, incision, blood vessel sealing, and the like. A pneumoperitoneum device11206injects gas into the body cavity through the pneumoperitoneum tube11111to inflate the body cavity of the patient11132for the purpose of ensuring a field of view by the endoscope11100and obtaining a working space of the operator. A recorder11207is a device capable of recording various kinds of information regarding surgery. A printer11208is a device capable of printing various kinds of information regarding surgery in various formats such as a text, an image, or a graph.

Note that the light source device11203for supplying irradiation light for imaging the surgical site to the endoscope11100may include, for example, an LED, a laser light source, or a white light source obtained by combining them. In a case where the white light source includes a combination of RGB laser light sources, an output intensity and an output timing of each color (each wavelength) can be controlled with high accuracy, whereby the light source device11203can adjust white balance of the captured image. Furthermore, in this case, images respectively corresponding to the R, G, and B can also be captured in time division by irradiating the target to be observed with laser light from each of the RGB laser light sources in time division, and controlling the driving of the imaging element of the camera head11102in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter in the imaging element.

Furthermore, the driving of the light source device11203may be controlled such that the intensity of light to be output is changed every predetermined time. The driving of the imaging element of the camera head11102is controlled in synchronization with a timing of changing the light intensity to obtain the images in time division, and the obtained images are synthesized, whereby an image with a high dynamic range that does not have so-called blocked up shadows and blown-out highlights can be generated.

Furthermore, the light source device11203may be configured to be able to supply light of a predetermined wavelength band adapted to special light observation. In the special light observation, so-called narrow band imaging is performed in which a predetermined tissue such as a blood vessel in a mucosal surface layer is imaged with high contrast by applying, for example, light in a narrower band than that of irradiation light (in other words, white light) used in normal observation using wavelength dependency of absorption of light in a body tissue. Alternatively, in the special light observation, fluorescence observation for obtaining an image with fluorescence generated by applying excitation light may be performed. In the fluorescence observation, it is possible to irradiate the body tissue with excitation light to observe fluorescence from the body tissue (autofluorescence observation) or to locally inject a reagent such as indocyanine green (ICG) to the body tissue and irradiate the body tissue with excitation light corresponding to a fluorescent wavelength of the reagent, thereby obtaining a fluorescent image, for example. The light source device11203can be configured to be able to supply narrow band light and/or excitation light adapted to such special light observation.

FIG.64is a block diagram showing an example of functional configurations of the camera head11102and the CCU11201shown inFIG.63.

The camera head11102includes a lens unit11401, an imaging unit11402, a drive unit11403, a communication unit11404, and a camera head controller11405. The CCU11201includes a communication unit11411, an image processor11412, and a controller11413. The camera head11102and the CCU11201are connected to each other so as to be able to communicate by a transmission cable11400.

The lens unit11401is an optical system provided at a connecting portion with the lens tube11101. The observation light captured from the distal end of the lens tube11101is guided to the camera head11102and enters the lens unit11401. The lens unit11401is constructed by combining a plurality of lenses including a zoom lens and a focus lens.

The imaging unit11402includes an imaging element. The number of imaging element constituting the imaging unit11402may be one (so-called single plate type) or two or more (so-called multiple plate type). In a case where the imaging unit11402is of the multiple-plate type, the image signals corresponding to RGB may be generated by the respective imaging elements, and a color image may be obtained by combining them, for example. Alternatively, the imaging unit11402may include a pair of imaging elements for obtaining right-eye and left-eye image signals corresponding to three-dimensional (3D) display. By the 3D display, the operator11131may grasp a depth of the living tissue in the surgical site more accurately. Note that, in a case where the imaging unit11402is of the multiple-plate type, a plurality of systems of lens units11401may be provided so as to correspond to the respective imaging elements.

Furthermore, the imaging unit11402is not necessarily provided in the camera head11102. For example, the imaging unit11402may be provided inside the lens tube11101immediately after the objective lens.

The drive unit11403includes an actuator and moves the zoom lens and the focus lens of the lens unit11401by a predetermined distance along an optical axis under the control of the camera head controller11405. Thus, the magnification and focal point of the image captured by the imaging unit11402may be appropriately adjusted.

The communication unit11404includes a communication device for transmitting and receiving various types of information to and from the CCU11201. The communication unit11404transmits the image signal obtained from the imaging unit11402as the RAW data to the CCU11201via the transmission cable11400.

Furthermore, the communication unit11404receives a control signal for controlling the drive of the camera head11102from the CCU11201and supplies the same to the camera head controller11405. The control signal includes, for example, information regarding imaging conditions such as information specifying a frame rate of the captured image, information specifying an exposure value during image capture, and/or information specifying the magnification and focal point of the captured image.

Note that the imaging conditions such as the abovementioned frame rate, exposure value, magnification, and focal point may be appropriately specified by the user or automatically set by the controller11413of the CCU11201on the basis of the obtained image signal. In the latter case, the endoscope11100is equipped with a so-called auto exposure (AE) function, an auto focus (AF) function, and an auto white balance (AWB) function.

The camera head controller11405controls the drive of the camera head11102on the basis of the control signal from the CCU11201received via the communication unit11404.

The communication unit11411includes a communication device for transmitting and receiving various types of information to and from the camera head11102. The communication unit11411receives the image signal transmitted from the camera head11102via the transmission cable11400.

Furthermore, the communication unit11411transmits the control signal for controlling the drive of the camera head11102to the camera head11102. The image signal and the control signal may be transmitted by electric communication, optical communication, and the like.

The image processor11412performs various types of image processing on the image signal which is the RAW data transmitted from the camera head11102.

The controller11413performs various types of control regarding image capture of the surgical site and the like by the endoscope11100and display of the captured image obtained by image capture of the surgical site and the like. For example, the controller11413generates the control signal for controlling drive of the camera head11102.

Furthermore, the controller11413allows the display device11202to display the captured image including the surgical site and the like on the basis of the image signal subjected to the image processing by the image processor11412. At that time, the controller11413may recognize various objects in the captured image using various image recognition technologies. For example, the controller11413may detect an edge shape, a color, and the like of the object included in the captured image, thereby recognizing the surgical instrument such as forceps, the specific living-body site, bleeding, mist when the energy treatment instrument11112is used, and the like. When allowing the display device11202to display the captured image, the controller11413may overlay various types of surgery support information on the image of the surgical site using a recognition result. The surgery support information is displayed as overlaid, and presented to the operator11131, so that it is possible to reduce the burden on the operator11131and enable the operator11131to reliably proceed with surgery.

The transmission cable11400connecting the camera head11102and the CCU11201is an electric signal cable corresponding to communication of electric signals, an optical fiber compatible with optical communication, or a composite cable thereof.

Here, in the illustrated example, the communication is performed by wire using the transmission cable11400, but the communication between the camera head11102and the CCU11201may be performed wirelessly.

An example of the endoscopic surgical system to which the technology according to the present disclosure may be applied has been described above. The technology according to the present disclosure may be applied to the imaging unit11402of the camera head11102in the configuration described above. Specifically, the camera package1or the camera module700may be applied as the imaging unit11402. By applying the technology according to the present disclosure to the imaging unit11402, it is possible to obtain a sharper surgical site image while making the camera head11102compact.

Note that, although the endoscopic surgical system is herein described as an example, the technology according to the present disclosure may also be applied to a microscopic surgical system and the like, for example.

<23. Example of Application to Mobile Object>

In addition, the technology according to the present disclosure may further be implemented as a device to be mounted on any type of mobile objects such as vehicles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobilities, airplanes, drones, ships, and robots, for example.

FIG.65is a block diagram showing a schematic configuration example of a vehicle control system which is an example of a mobile object control system to which the technology according to the present disclosure can be applied.

A vehicle control system12000includes a plurality of electronic control units connected to each other via a communication network12001. In the example shown inFIG.65, the vehicle control system12000includes a drive system control unit12010, a body system control unit12020, a vehicle external information detection unit12030, a vehicle internal information detection unit12040, and an integrated control unit12050. Further, a microcomputer12051, a sound/image output unit12052, and an in-vehicle network interface (I/F)12053are illustrated as the functional configuration of the integrated control unit12050.

The drive system control unit12010controls the operation of devices related to a drive system of a vehicle according to various programs. For example, the drive system control unit12010functions as a control device over a driving force generating device such as an internal combustion engine or a driving motor for generating a driving force of the vehicle, a driving force transmission mechanism for transmitting the driving force to wheels, a steering mechanism adjusting a steering angle of the vehicle, a braking device that generates a braking force of the vehicle, and the like.

The body system control unit12020controls operations of various devices mounted on the vehicle body according to various programs. For example, the body system control unit12020functions as a keyless entry system, a smart key system, a power window device, or a control device for various lamps such as a headlamp, a backup lamp, a brake lamp, a blinker, or a fog lamp. In this case, radio waves transmitted from a portable device that can be used as a key or signals from various switches may be input to the body system control unit12020. The body system control unit12020receives input of these radio waves or signals, and controls a door lock device, power window device, lamps, and the like of the vehicle.

The vehicle external information detection unit12030detects information regarding the outside of the vehicle equipped with the vehicle control system12000. For example, the vehicle external information detection unit12030is connected with an imaging unit12031. The vehicle external information detection unit12030causes the imaging unit12031to capture an image outside the vehicle, and receives the captured image. The vehicle external information detection unit12030may perform, on the basis of the received image, a process of detecting an object such as a person, a vehicle, an obstacle, a road sign, or a character on a road surface, or a process of detecting the distance thereto.

The imaging unit12031is an optical sensor that receives light and outputs an electric signal corresponding to the amount of received light. The imaging unit12031can output an electric signal as an image or as information for distance measurement. Further, the light received by the imaging unit12031may be visible light or invisible light such as infrared rays.

The vehicle internal information detection unit12040detects information regarding the inside of the vehicle. For example, the vehicle internal information detection unit12040is connected with a driver condition detection unit12041that detects a condition of a driver. The driver condition detection unit12041may include, for example, a camera that captures an image of the driver. On the basis of detection information input from the driver condition detection unit12041, the vehicle internal information detection unit12040may calculate a degree of fatigue of the driver or a degree of concentration of the driver, or may determine whether or not the driver is dozing.

The microcomputer12051can calculate a control target value for the driving force generating device, the steering mechanism, or the braking device on the basis of the information about the inside and outside of the vehicle obtained by the vehicle external information detection unit12030or the vehicle internal information detection unit12040, and output a control command to the drive system control unit12010. For example, the microcomputer12051may perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which include collision avoidance or shock mitigation for the vehicle, following driving based on distance between vehicles, vehicle speed maintaining driving, a warning of collision of the vehicle, a warning of lane departure of the vehicle, or the like.

In addition, the microcomputer12051may perform cooperative control intended for automatic driving, which makes the vehicle to travel autonomously without the need of the operation of the driver, or the like, by controlling the driving force generating device, the steering mechanism, the braking device, or the like on the basis of the information about the surrounding situation of the vehicle obtained by the vehicle external information detection unit12030or the vehicle internal information detection unit12040.

Further, the microcomputer12051can output a control command to the body system control unit12020on the basis of information about the outside of the vehicle acquired by the vehicle external information detection unit12030. For example, the microcomputer12051may perform cooperative control including controlling the head lamps on the basis of the location of a preceding vehicle or an oncoming vehicle detected by the vehicle external information detection unit12030and changing high beams to low beams, for example, for the purpose of anti-glare.

The sound/image output unit12052transmits an output signal of at least one of a sound or an image to an output device capable of visually or auditorily giving information to an occupant of the vehicle or the outside of the vehicle. In the example ofFIG.65, an audio speaker12061, a display unit12062, and an instrument panel12063are illustrated as the output device. The display unit12062may include, for example, at least one of an on-board display or a head-up display.

FIG.66is a diagram showing examples of mounting positions of the imaging unit12031.

InFIG.66, a vehicle12100includes, as the imaging unit12031, imaging units12101,12102,12103,12104, and12105.

For example, the imaging units12101,12102,12103,12104, and12105are provided at positions such as the front nose, the side-view mirrors, the rear bumper or the back door, and an upper part of the windshield in the cabin of the vehicle12100. The imaging unit12101provided on the front nose and the imaging unit12105provided at the upper part of the windshield in the cabin of the vehicle mainly acquire an image of an environment in front of the vehicle12100. The imaging units12102and12103on the side-view mirrors mainly obtain an image of an environment on the side of the vehicle12100. The imaging unit12104provided in the rear bumper or the back door mainly obtains an image of an environment behind the vehicle12100. The images of the environment in front of the vehicle obtained by the imaging units12101and12105are mainly used for detecting a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

Note thatFIG.66shows examples of image capture ranges of the imaging units12101to12104. An imaging range12111indicates the imaging range of the imaging unit12101on the front nose, imaging ranges12112and12113indicate the imaging ranges of the imaging units12102and12103on the side-view mirrors, respectively, and an imaging range12114indicates the imaging range of the imaging unit12104on the rear bumper or the back door. For example, a bird's-eye image of the vehicle12100as viewed from above can be obtained by superimposing image data captured by the imaging units12101to12104.

For example, the microcomputer12051obtains the distance between the vehicle12100and each three-dimensional object in the imaging ranges12111to12114and the temporal change (relative speed to the vehicle12100) of the distance on the basis of the distance information obtained from the imaging units12101to12104, and may extract, as a preceding vehicle, especially a three-dimensional object which is the closest to the vehicle12100on the path on which the vehicle12100is traveling and which is traveling at a predetermined speed (e.g., 0 km/h or more) in the direction substantially the same as the traveling direction of the vehicle12100. Further, the microcomputer12051may perform autobrake control (including follow-up stop control), automatic acceleration control (including follow-up start-driving control), and the like by presetting a distance to be maintained between the vehicle12100and a preceding vehicle. In this way, it is possible to perform cooperative control intended to achieve autonomous driving without the need of drivers' operations, and the like.

For example, the microcomputer12051may sort three-dimensional object data of three-dimensional objects into motorcycles, standard-size vehicles, large-size vehicles, pedestrians, and the other three-dimensional objects such as utility poles on the basis of the distance information obtained from the imaging units12101to12104, extract data, and use the data to automatically avoid obstacles. For example, the microcomputer12051sorts obstacles around the vehicle12100into obstacles that a driver of the vehicle12100can see and obstacles that it is difficult for the driver to see. Then, the microcomputer12051determines a collision risk, which indicates a hazard level of a collision with each obstacle. When the collision risk is equal to or higher than a preset value and thus there is a possibility of collision, the microcomputer12051may perform driving assistance to avoid a collision by outputting a warning to the driver via the audio speaker12061or the display unit12062, or by forcibly reducing the speed or performing collision-avoidance steering via the drive system control unit12010.

At least one of the imaging units12101to12104may be an infrared camera that detects infrared light. For example, the microcomputer12051may recognize a pedestrian by determining whether or not images captured by the imaging units12101to12104include the pedestrian. The method of recognizing a pedestrian includes, for example, a step of extracting feature points in the images captured by the imaging units12101to12104being infrared cameras, and a step of performing a pattern matching process with respect to a series of feature points indicating an outline of an object, to thereby determine whether or not the object is a pedestrian. When the microcomputer12051determines that the images captured by the imaging units12101to12104include a pedestrian and recognizes the pedestrian, the sound/image output unit12052controls the display unit12062such that a rectangular contour is displayed overlaid on the recognized pedestrian to emphasize the pedestrian. Further, the sound/image output unit12052may control the display unit12062such that an icon or the like indicating a pedestrian is displayed at a desired position.

An example of the vehicle control system to which the technology according to the present disclosure can be applied has been described above. The technology according to the present disclosure can be applied to the imaging unit12031and the like in the configuration described above. Specifically, the camera package1or the camera module700can be applied as the imaging unit12031. By applying the technology according to the present disclosure to the imaging unit12031, it is possible to obtain a captured image that is easier to see and to acquire distance information while achieving reduction in size. In addition, the obtained captured image and distance information can be used to reduce driver's fatigue and improve the safety level of the driver and the vehicle.

Further, the present disclosure is applicable not only to molding of lenses (lens resin parts) included in the camera package, but also to general imprinting in which a resin is molded using a mold.

It should be noted that the embodiments according to the present disclosure are not limited to the abovementioned embodiments, and various modifications are possible without departing from the gist of the present disclosure.

For example, it is possible to adopt a mode obtained by combining all or some of the plurality of embodiments described above.

It should be noted that the effects described in the present specification are merely illustrative and not restrictive, and effects other than those described in the present specification may also be provided.

It is to be noted that the present disclosure may also have the following configurations.(1)A camera package including:a solid-state imaging element; anda lens formed above a transparent substrate that protects the solid-state imaging element,in which a lens formation region in which the lens is formed above the transparent substrate and a lens free region around the lens formation region differ in contact angle.(2)The camera package according to (1) described above,in which the lens formation region and the lens free region differ in contact angle due to a high contact angle film formed in the lens free region.(3)The camera package according to (1) or (2) described above,in which the lens formation region and the lens free region differ in contact angle due to a hydrophilic film formed in the lens formation region.(4)The camera package according to (1) or (3) described above,in which the lens formation region and the lens free region differ in contact angle due to micro-irregularities formed in the lens free region.(5)The camera package according to any one of (1) to (4) described above,in which the lens formation region of the transparent substrate has an average height lower than an average height of the lens free region.(6)The camera package according to (5) described above,in which the lens formation region of the transparent substrate is recessed to generate a difference in height between the lens formation region and the lens free region.(7)The camera package according to (5) described above,in which the lens free region of the transparent substrate is provided with a thick film to generate a difference in height between the lens formation region and the lens free region.(8)The camera package according to any one of (1) to (4) described above,in which the lens formation region of the transparent substrate has a shape extending outward from a rectangular region with nearness to four corners of the rectangular region from a lens center of the rectangular region.(9)The camera package according to any one of (1) to (4) described above,in which the lens formation region of the transparent substrate is separated from the lens formation region at a first curve that circumscribes a long side of a rectangular shape and that has a predetermined radius of curvature, a second curve that circumscribes a short side of the rectangular shape and that has a predetermined radius of curvature, and a region in which the first curve and the second curve are connected to each other with a curve, a straight line, or a point.(10)The camera package according to (1) described above, further includinga high contact angle film in the lens free region above the transparent substrate,in which the high contact angle film or the transparent substrate has optical absorption property, or a light absorbing film or a light reflection film is provided between the high contact angle film and the solid-state imaging element.(11)The camera package according to (10) described above,in which the light absorbing film is formed in the lens free region.(12)The camera package according to (10) described above,in which the light absorbing film is formed in the lens formation region and in the lens free region.(13)The camera package according to (10) described above,in which the light absorbing film is formed between the transparent substrate and the high contact angle film.(14)The camera package according to (10) described above, further includingan adhesion promoter on the transparent substrate,in which the light absorbing film is formed on the adhesion promoter.(15)The camera package according to (10) described above,in which the light absorbing film is formed between the transparent substrate and the solid-state imaging element.(16)The camera package according to (10) described above,in which the high contact angle film has optical absorption property.(17)The camera package according to (10) described above,in which the transparent substrate has optical absorption property.(18)The camera package according to any one of (10) to (17) described above, further includingan antireflection structure on an upper surface of a semiconductor substrate of the solid-state imaging element.(19)A method for manufacturing a camera package, the method including:performing processing such that a lens formation region above a transparent substrate that protects a solid-state imaging element and a lens free region around the lens formation region differ in contact angle; dropping a lens material into the lens formation region above the transparent substrate; and pressing a mold to form a lens.(20)An electronic device including:a camera package includinga solid-state imaging element, anda lens formed above a transparent substrate that protects the solid-state imaging element,in which a lens formation region in which the lens is formed above the transparent substrate and a lens free region around the lens formation region differ in contact angle; anda lens module including one or more lens-equipped substrates disposed above the camera package.

REFERENCE SIGNS LIST