PRESSURE SENSOR APPARATUS

A pressure sensor apparatus, including: a substrate; a sensor provided on the substrate and configured to measure absolute pressure; a cover attached to the substrate to form a housing space, in which the sensor is housed, with the substrate; and a shield member. The cover is attached to the substrate with the shield member disposed therebetween and fully blocking passage of air therebetween. The cover has a hole through which the housing space communicates with an outside of the housing space.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority pursuant to 35 U.S.C. § 119 from Japanese patent application number 2023-114024 filed on Jul. 11, 2023, the entire disclosure of which is hereby incorporated by reference herein.

BACKGROUND

Technical Field

The present disclosure relates to a pressure sensor apparatus.

A typical pressure sensor apparatus includes a pressure sensor having a diaphragm provided on a semiconductor substrate, and a package in which the pressure sensor is housed (refer to Japanese Patent Laid-open No. 2015-222175, for example).

In some pressure sensor apparatuses, a tube is directly attached to a cap that covers the package. In such a pressure sensor apparatus, when the tube is attached to the cap, force is sometimes applied to the semiconductor substrate and a terminal (so-called a lead frame) extending from the package, which potentially degrades measurement accuracy of the pressure sensor apparatus.

SUMMARY

A first aspect of an embodiment of the present disclosure to solve the above-mentioned problem is a pressure sensor apparatus that includes a substrate; a sensor provided on the substrate and configured to measure absolute pressure; a cover attached to the substrate to form a housing space, in which the sensor is housed, with the substrate; and a shield member, wherein the cover is attached to the substrate with the shield member disposed therebetween and fully blocking passage of air therebetween, and the cover has a hole through which the housing space communicates with an outside of the housing space.

A second aspect of an embodiment of the present disclosure to solve the above-mentioned problem is a pressure sensor apparatus that includes a substrate; a first sensor provided on the substrate and configured to measure absolute pressure; a second sensor provided on the substrate and configured to measure the absolute pressure; a cover attached to the substrate to form a first housing space, in which the first sensor is housed, and a second housing space, in which the second sensor is housed, with the substrate; and a shield member, wherein the cover has a first hole through which the first housing space communicates with an outside of the first housing space, and a second hole through which the second housing space communicates with an outside of the second housing space, the shield member is positioned between the cover and the substrate, and is configured to fully block passage of air therebetween, and the shield member includes a first part and a second part that enclose the first housing space and the second housing space respectively in a plan view of the pressure sensor apparatus, and the first part and the second part share a common part.

DETAILED DESCRIPTION

At least following matters will become apparent from the present description and the accompanying drawings. The same or equivalent components, members, and the like illustrated in the drawings are given by the same reference numerals, and a description thereof is omitted as appropriate.

Typical Pressure Sensor Apparatus

FIG.1Ais a perspective view of a typical pressure sensor apparatus10, andFIG.1Bis a partial cross-sectional view along line A-A inFIG.1A.

<<Definitions of Directions and the Like>>

First, directions and the like of the pressure sensor apparatus10are defined with reference toFIG.1A. A direction from left to right on the sheet in a longitudinal direction of a substrate20on a plane is defined as a “+X direction”, and its opposite direction (in other words, a direction from right to left on the sheet in the longitudinal direction of the substrate20) is defined as a “−X direction”.

A direction from back to front on the sheet in a width direction of the substrate20is defined as a “+Y direction”, and its opposite direction (in other words, a direction from front to back on the sheet in the width direction of the substrate20) is defined as a “−Y direction”. In addition, a direction orthogonal to the substrate20and pointing upward on the sheet is defined as a “+Z direction”, and its opposite direction (in other words, a direction orthogonal to the substrate20and pointing downward) is defined as a “−Z direction”.

Both the +X direction and the −X direction are also simply referred to as an “X direction”. Similarly, both the +Y direction and the −Y direction are also simply referred to as a “Y direction”. In addition, both the +Z direction and the −Z direction are also simply referred to as a “Z direction”.

InFIG.1A, the +X direction, the +Y direction, and the +Z direction are illustrated as line segments with arrows to facilitate understanding of the directions and the like of the pressure sensor apparatus10. In the following description, the +X direction is referred to as a “right direction”, the −X direction is referred to as a “left direction”, and the X direction is referred to as a “right-left direction” in some cases. The +Y direction is referred to as a “front direction (or a front side)”, the −Y direction is referred to as a “back direction (or a back side)”, and the Y direction is referred to as a “front-rear direction” in some cases. The +Z direction is referred to as an “upward direction (or an upside direction)”, the −Z direction is referred to as a “downward direction (or a downside direction)”, and the Z direction is referred to as an “up-down direction” or a “height direction” in some cases.

The above-described definitions of directions and the like apply throughout the present specification unless otherwise stated.

<<Configuration of Pressure Sensor Apparatus10>>

The pressure sensor apparatus10is an apparatus to measure the pressure of gas that flows in and out through a tube11, and the pressure sensor apparatus10is configured to include the substrate20and a sensor21. The substrate20is a member having an upper surface (hereinafter, also referred to as an “upside surface” as appropriate) to which the sensor21is attached. For example, pattern wiring for applying power supply voltage to the sensor21, pattern wiring for transmitting signals from the sensor21, and a ground pattern (not illustrated) are formed on the substrate20.

The sensor21is a device to measure the pressure of gas flowing in or out through the tube11and the sensor21is configured to include, for example, a package30, a measurement unit31, terminals32, a protection member33, and a cap34as illustrated inFIG.2.

The package30is a member made of, for example, resin and formed with a recessed part in which the measurement unit31(described later) is housed. Each terminal32is a metal member corresponding to so-called a lead frame and electrically couples a semiconductor chip51(described later) included in the measurement unit31to the substrate20through a wire53(described later). The package30corresponds to a “housing part” in which the semiconductor chip51(that is, a semiconductor substrate) is housed.

The protection member33is a protection gel protecting the semiconductor chip51and the wires53, of the measurement unit31. The protection member33is, for example, a silicone gel but may be a fluorine gel or the like. The cap34is a member that covers the package30and to which the tube11is attached, and is made of, for example, resin. The cap34includes a lid part40having a circular shape in a plan view seen from the upward direction (+Z direction), and an introduction pipe41into which the tube11is inserted.

The introduction pipe41is a cylindrical part extending in the upward direction at a substantially central part of the lid part40in a circular shape. A hole42is formed inside the introduction pipe41, and accordingly, gas can flow into or out of the inside of the cap34through the hole42.

The cap34is attached to the package30by a bonding agent (not illustrated) or the like such that a space (hereinafter, a space S1) formed inside the sensor21by the package30and the cap34is sealed when the hole42is blocked.

The measurement unit31is housed in the recessed part formed in the package30and measures the absolute pressure in the sensor21, and the measurement unit31is configured to include the semiconductor chip51in which a diaphragm50is formed, a base52, and the wires53. The “absolute pressure” is pressure with respect to pressure in vacuum. The measurement unit31is housed in the recessed part of the package30and then fixed by a bonding agent61.

The semiconductor chip51is a silicon chip in which the diaphragm50and a bridge circuit (not illustrated) including a plurality of piezo resistors on the diaphragm50are formed. The base52is a member (for example, a glass member) supporting the semiconductor chip51and is anodically joined to the semiconductor chip51. A vacuum space between the semiconductor chip51and the base52is a vacuum reference chamber60. The semiconductor chip51corresponds to a “semiconductor substrate”.

Each wire53is a metal member (so-called a bonding wire) coupling a pad (not illustrated) on the upside surface of the semiconductor chip51to a terminal32.

In such a pressure sensor apparatus10, force in the downward direction (−Z direction) is applied to the cap34including the introduction pipe41when the tube11is attached to the introduction pipe41. As a result, force is also applied to the terminals32and the measurement unit31in some cases, which potentially degrades measurement accuracy of the pressure sensor apparatus10. The following describes pressure sensor apparatuses of the present embodiment, which are capable of preventing degradation of the measurement accuracy.

Present Embodiment

FIG.3Ais a perspective view of a pressure sensor apparatus15, andFIG.3Bis a partial cross-sectional view along line B-B inFIG.3A. The pressure sensor apparatus15is configured to include a substrate100, the sensor21, a cover110a,and screws150. The sensor21of the pressure sensor apparatus15is described above and thus detailed description thereof is omitted.

The substrate100is a similar member to or the same member as the substrate20, and has an upside surface on which the sensor21is attached and a plurality of wiring patterns are formed. As illustrated in the lower-right enlarged view inFIG.3B, the substrate100is formed with openings101corresponding to the screws150(described later).

The cover110ais attached to the upside surface of the substrate100from above to form a housing space S2(described later in detail) in which the sensor21is housed. The cover110aincludes a ceiling part111, an introduction pipe112, a wall part113a,attachment parts114, and slits115.

The ceiling part111is a plate part corresponding to a ceiling part of the cover110a.The cylindrical introduction pipe112extending upward is formed at a substantially central part of the ceiling part111in a plan view seen from the upward direction. A hole120is formed inside the introduction pipe112so that gas is flowed in and out between the housing space S2and an external space, through the hole120.

The wall part113aextending in the downward direction is formed from the back surface of the ceiling part111. Specifically, the tubular wall part113ais formed on the back surface of the ceiling part111to surround the sensor21.

The attachment parts114for attaching the cover110ato the substrate100extend in the downward direction from the back surface of the ceiling part111at respective end parts of the back surface of the ceiling part111in the right-left direction. As illustrated in the lower-right enlarged view inFIG.3B, each attachment part114is formed with a screw hole121corresponding to a screw150(described later). Each slit115is formed from the lower side of the cover110ato the upper side, between the wall part113aand the corresponding attachment part114.

In the pressure sensor apparatus15, for example, a bonding agent122as so-called a “seal” is applied at a lower end part of the wall part113abefore the cover110ais attached to the substrate100. In the present embodiment, the cover110ais disposed such that the sensor21of the substrate100is positioned inside the tubular wall part113aand the center of each opening101matches the center of the opening of the corresponding screw hole121.

Then, the screws150are inserted into the screw holes121through the openings101from the back surface side of the substrate100, and accordingly, the cover: and the substrate100are fixed to each other by the screws150. As a result, the cover110ais attached to the substrate100. The bonding agent122eliminates the gap between the wall part113aand the substrate100when the cover110ais attached to the substrate100(fixed by the screws150).

Accordingly, in the present embodiment, the bonding agent122shields the inside of the housing space S2from the outside so that the housing space S2is sealed when the hole120is blocked. The “housing space S2” is a space surrounded by the ceiling part111, the wall part113a,the bonding agent122, and the substrate100.

As inFIG.1A, a tube (not illustrated) is attached to the introduction pipe112of the cover110aof the pressure sensor apparatus15. In the present embodiment, the cover110adirectly contacts the substrate100but does not directly contact the sensor21. Thus, force is not directly applied to the sensor21through the cover110a,and accordingly, the pressure sensor apparatus15of the present embodiment can accurately measure absolute pressure in the housing space S2.

Moreover, in the present embodiment, since the slits115are each provided between the wall part113aand the corresponding attachment part114, it is possible to reduce force conveyed from the attachment parts114to the wall part113awhen the screws150are inserted into the screw holes121of the attachment parts114. Thus, it is possible to reduce influence on the sensor21when the cover101ais fixed to the substrate100.

The bonding agent122corresponds to a “shield member” for sealing the housing space S2in a state in which the hole120is blocked.

A pressure sensor apparatus16is an apparatus including an O ring126as a “seal” in place of the bonding agent122of the pressure sensor apparatus15and the pressure sensor apparatus16is configured to include the substrate100, the sensor21, a cover110b,and the screws150as illustrated inFIGS.3A and3C. The pressure sensor apparatus16is the same as the pressure sensor apparatus15except for the cover110band the O ring126, and thus the following description will be made on the cover110band the O ring126.

The cover110bis a similar member to or the same member as the cover110a,and attached to the upside surface of the substrate100from above to form a housing space S3in which the sensor21is housed. The cover110bincludes the ceiling part111, the introduction pipe112, a wall part113b,the attachment parts114, and the slits115. The cover110bis the same as the cover110aexcept for the wall part113b,and thus the following description will be made on the wall part113b.

The wall part113bis a member extending in the downward direction from the back surface of the ceiling part111. In the present embodiment, the tubular wall part113bis formed on the back surface of the ceiling part111to surround the sensor21. A groove125is formed at a lower end part of the wall part113b.The O ring126made of resin is fitted to the groove125.

The O ring126eliminates the gap between the wall part113band the substrate100when the cover110bis attached to the substrate100(fixed by the screws150). Accordingly, in the present embodiment, the O ring126shields the inside of the housing space S3from the outside so that the housing space S3is sealed when the hole120is blocked. The “housing space S3” is a space surrounded by the ceiling part111, the wall part113b,the O ring126, and the substrate100.

As inFIG.1A, a tube (not illustrated) is attached the introduction pipe112of the cover110bof the pressure sensor apparatus16. In the present embodiment, the cover110bdirectly contacts the substrate100but does not directly contact the sensor21. Thus, force is not directly applied to the sensor21through the cover110b,and accordingly, the pressure sensor apparatus16of the present embodiment can accurately measure absolute pressure in the housing space S3.

In the present embodiment, since the slits115are each provided between the wall part113band the corresponding attachment part114, it is possible to reduce force conveyed from the attachment parts114to the wall part113bwhen the150are inserted into the screw holes121of the screws attachment parts114. Thus, it is possible to reduce influence on the sensor21when the cover110bis fixed to the substrate100.

The O ring126corresponds to a “shield member” for sealing the housing space S3in a state in which the hole120is blocked.

FIG.4Ais a perspective view of a pressure sensor apparatus17,FIG.4Bis a plan view of the pressure sensor apparatus17, andFIG.4Cis a partial cross-sectional view along line C-C inFIG.4B. The pressure sensor apparatus17is configured to include the substrate100, the sensor21, a cover140, and the screws150. The pressure sensor apparatus17is the same as the pressure sensor apparatus15inFIG.3Aexcept for the cover140, and thus the following description will be mainly made on the cover140. InFIG.4B, illustration of a bonding agent205is omitted for convenience.

The cover140is attached to the upside surface of the substrate100from above to form a housing space S4(described later in detail) in which the sensor21is housed. The cover140includes a first member200, a second member201, and coupling parts202ato202d,attachment parts203, and slits204.

The first member200is a member covering the sensor21from above and forming the housing space S4in which the sensor21is housed, and the first member200is configured to include a ceiling part210, an introduction pipe211, and a wall part212. The ceiling part210is a plate part corresponding to a ceiling part of the first member200. The cylindrical introduction pipe211extending upward is formed at a substantially central part of the ceiling part210in a plan view seen from the upward direction.

A hole230is formed inside the introduction pipe211so that gas is flowed in and out between the housing space S4and an external space, through the hole230.

The wall part212extending in the downward direction in a cylindrical shape is formed from the back surface of the ceiling part210. Specifically, the wall part212is formed on the back surface of the ceiling part210to surround the sensor21.

The second member201is a tubular member surrounding the first member200. Accordingly, a gap is formed between the first member200and the second member201. The height of the second member201from the upside surface of the substrate100is lower than the height of the first member200from the upside surface of the substrate100.

The coupling part202ais a member coupling the first member200and the second member201at the right surface of the first member200as illustrated inFIG.4A. The coupling part202bcouples the first member200and the second member201at the front surface of the first member200, and the coupling part202ccouples the first member200and the second member201at the left surface of the first member200. The coupling part202dcouples the first member200and the second member201at the back surface of the first member200.

The attachment parts203are parts for attaching the cover140to the substrate100and formed at respective end parts of the second member201in the right-left direction. Screw holes231corresponding to the screws150(described later) are formed at the attachment parts203. In the present embodiment, each slit204is formed from the lower side of the cover140to the upper side between the second member201and the corresponding attachment part203.

In the present embodiment, the cover140is disposed such that the sensor21of the substrate100is positioned inside the tubular wall part212and the center of the opening101matches the center of the opening of the corresponding screw hole231.

The screws150are inserted into the screw holes231through the openings101from the back surface side of the substrate100, and accordingly, the cover140and the substrate100are fixed to each other by the screws150. As a result, the cover140is attached to the substrate100.

As described above, a gap is formed between the first member200and the second member201. In the present embodiment, when the bonding agent205is filled between the first member200and the second member201, they can eliminate the gap between the first member200and the second member201. The bonding agent205of the present embodiment is, for example, a potting material of silicon resin, but is not limited thereto and may be a potting material of urethane resin or epoxy resin.

The coupling parts202ato202dis provided at a position separated from the substrate100when the cover140is attached to the substrate100. Accordingly, the bonding agent205can reliably eliminate the gap between the first member200and the second member201.

The bonding agent205of the present embodiment shields the inside of the housing space S4from the outside so that the housing space S4is sealed when the hole230is blocked. The “housing space S4” is a space surrounded by the inside of the first member200, the bonding agent205, and the substrate100.

As inFIG.1A, a tube (not illustrated) is attached to the introduction pipe211of the cover140of the pressure sensor apparatus17. In the present embodiment, the cover140directly contacts the substrate100but does not directly contact the sensor21. Thus, force is not directly applied to the sensor21through the cover140, and accordingly, the pressure sensor apparatus17of the present embodiment can accurately measure absolute pressure in the housing space S4.

In the present embodiment, since the slits204are each provided between the second member201and the corresponding attachment part203, it is possible to reduce force conveyed from the attachment parts203to the first member200when the screws150are inserted into the screw holes2312of the attachment parts203. Thus, it is possible to reduce influence on the sensor21when the cover140is fixed to the substrate100.

The bonding agent205corresponds to a “shield member” for sealing the housing space S4in a state in which the hole230is blocked.

FIG.5Ais an exploded perspective view of a pressure sensor apparatus18, andFIG.5Bis a diagram for description of a cover320and a shield member350of the pressure sensor apparatus18.FIG.5Cis a plan view of the pressure sensor apparatus18,FIG.5Dis a cross-sectional view along line E-E inFIG.5C, andFIG.5Eis a cross-sectional view along line F-F inFIG.5C.

The pressure sensor apparatus18is an apparatus capable of measuring absolute pressure in four spaces and is configured to include a substrate300, screws302ato302f,sensors310ato310d,the cover320, and the shield member350. The substrate300is a member having an upside surface to which the sensors310ato310dare attached. For example, pattern wiring for applying power supply voltage to the sensors310ato310d,pattern wiring for transferring signals from the sensors310ato310d,and a ground pattern (not illustrated) are formed on the substrate300.

The substrate300is provided with openings301ato301fcorresponding to the respective screws302ato302f(described later). The screws302ato302fare members for fixing the substrate300to the cover320.

The sensor310ameasures the pressure (in this example, absolute pressure) of gas flowing in or out through an introduction pipe321a(described later).FIG.6is a cross-sectional view along D-D line inFIG.5A, and the sensor310ais configured to include the measurement unit31, a package500, terminals510, a protection member520, and a cap530. The measurement unit31included in the sensor310ainFIG.6has the same configuration as illustrated inFIG.2, for example. InFIG.2, the measurement unit31is housed at a part recessed on the lower side in the package30so that the measurement unit31can measure the pressure of gas on the upper side of the measurement unit31. InFIG.6, the measurement unit31is housed at a part recessed on the upper side in the package500so that the measurement unit31can measure the pressure of gas on the lower side of the measurement unit31.

The package500is a member made of, for example, resin and formed with the recessed part in which the measurement unit31is housed. The terminals510are metal members (so-called lead frames) similar to or the same as the terminals32inFIG.2and electrically couple the semiconductor chip51included in the measurement unit31to the substrate300together with the wires53. The package500corresponds to a “housing part” in which the semiconductor chip51(that is, a semiconductor substrate) is housed.

The protection member520is a protection gel covering the measurement unit31and protecting the semiconductor chip51and the wires53, of the measurement unit31. The cap530is a member covering an opening on the lower side of the package30and made of, for example, resin.

An opening531for measuring pressure is provided substantially at the center of the cap530. Accordingly, the sensor310ainFIG.6can measure the pressure of gas from the lower side of the sensor310a.The sensor310aincludes the cap530in this example, but is not limited thereto and may include no cap530. In such a case as well, the sensor310acan appropriately measure the pressure of gas.

The sensors310bto310dare devices configured to measure the absolute pressure of gas flowing in or out through respective introduction pipes321bto321d(described later). The sensors310bto310dhave the same configuration as the sensor310a,and thus detailed description thereof will be omitted.

The cover320inFIG.5Ais attached to the upside surface of the substrate300from above to form housing spaces S10to S13(described later in detail) in which the respective sensors310ato310dare housed. As illustrated inFIGS.5A and5B, the cover320has a substantially rectangular parallelepiped shape and includes the introduction pipes321ato321d,screw holes322ato322f,a wall part323, and partition parts324ato324c.

The introduction pipe321ais a part formed with a hole330acommunicating with the housing space S10(described later) and is provided at the side surface of the cover320on the front side. Similarly to the introduction pipe321a,the introduction pipes321bto321dare parts formed with holes330bto330dcommunicating with the housing spaces S11to S13(described later), respectively, and are provided at the side surface of the cover320on the front side.

The screw holes322ato322fare holes corresponding to the respective openings301ato301fof the substrate300when the cover320is attached to the substrate300, and the screws302ato302fare inserted into the respective screw holes.

The wall part323is a part surrounding a recessed part formed at the back surface of the cover320, and a space surrounded by the wall part323is divided by the three partition parts324ato324c.As a result, the space surrounded by the wall part323is divided into four spaces by the three partition parts324ato324c.

In the present embodiment, the “housing space S10” is the rightmost space among the above-described four spaces and surrounded by the inside of the cover320, a part351a(described later) corresponding to an O ring, and the substrate300. The “housing space S11” is the second rightmost space among the above-described four spaces and surrounded by the inside of the cover320, a part351b(described later) corresponding to an O ring, and the substrate300.

The “housing space S12” is the third rightmost (that is, the second leftmost) space among the above-described four spaces and surrounded by the inside of the cover320, a part351c(described later) corresponding to an O ring, and the substrate300. The “housing space S13” is the leftmost space among the above-described four spaces and surrounded by the inside of the cover320, a part351d(described later) corresponding to an O ring, and the substrate300.

In this manner, in the present embodiment, the recessed part formed at the back surface of the cover320is divided by the three partition parts324ato324c,and accordingly, the four housing spaces S10to S13are formed.

The shield member350is a member (seal) for sealing the housing spaces S10to S13. As illustrated inFIG.5B, the shield member350of the present embodiment is provided with the four parts351ato351dcorresponding to O rings. The part351ais a part for sealing the housing space S10, and the part351bis a part for sealing the housing space S11. In addition, the part351cis a part for sealing the housing space S12, and the part351dis a part for sealing the housing space S13.

In the present embodiment, the four parts351ato351dhave substantially square shapes in a plan view from above. The parts351aand351bshare a side between the parts351aand351b,and accordingly include a part352common to both members. The parts351band351cshare a side between the parts351band351cand accordingly include a part353common to both members, and the parts351cand351dshare a side between the parts351cand351dand accordingly include a part354common to both members.

In the present embodiment, for example, the sensor310acorresponds to a “first sensor”, and the sensor310bcorresponds to a “second sensor”. The housing space S10corresponds to a “first housing space”, and the housing space S11corresponds to a “second housing space”. The hole330acorresponds to a “first hole”, and the hole330bcorresponds to a “second hole”. The part351aof the shield member350for sealing the housing space S10corresponds to a “first part”, and the part351bof the shield member350for sealing the housing space S11corresponds to a “second part”. The parts351aand351binclude the common part352.

In the present embodiment, the cover320is attached to the substrate300in a state in which the shield member350is fitted to a groove (described later) at the back surface of the cover320. Specifically, the screws302ato302fare inserted into the openings301ato301fand the screw holes322ato322fin a state in which the cover320is temporarily fixed to the substrate300by clicks of the cover320.

The following description will be made on the part352of the shield member350with reference toFIG.5D. A groove360to which the part352of the shield member350is fitted is formed at the partition part324aof the cover320of the present embodiment. The part352of the shield member350eliminates the gap between the partition part324aand the substrate300when the cover320is attached to the substrate300in a state in which the part352is fitted to the groove360.

The above description is made on the gap between the partition part324aand the substrate300, and also applies to other places (for example, the gap between the partition part324band the substrate300and the gap between the partition part324cand the substrate300) where the groove360is formed and the shield member350is fitted. In addition, the groove360is formed at the wall part323, and thus the shield member350eliminates the gap between the wall part323and the substrate300. Accordingly, in the present embodiment, the housing spaces S10to S13are sealed when the holes330ato330dof the respective introduction pipes321ato321dare blocked.

As inFIG.1A, tubes (not illustrated) are attached to the introduction pipes321ato321dof the cover320of the pressure sensor apparatus18. In the present embodiment, the cover320directly contacts the substrate300but does not directly contact the sensors310ato310d.Thus, force is not directly applied to the sensors310ato310dthrough the cover320, and accordingly, the pressure sensor apparatus18of the present embodiment can accurately measure absolute pressure in the housing spaces S10to S13.

Although one shield member350is provided in the above description, for example, four O rings with which the four parts351ato351dare separated may be provided. However, a larger space in the right-left direction is needed in a case where four O rings are provided. In the present embodiment, since the shield member350includes the shared parts352to354, space saving can be achieved even in a case where the four sensors310ato310dare disposed in the right-left direction.

In the pressure sensor apparatus18, as illustrated inFIG.5E, the sensor310ais disposed such that the semiconductor chip51is not positioned on an extended line of a central axis A0of the hole330a(in this example, the central axis of an opening part of the introduction pipe321aformed with the hole330a). Accordingly, it is possible to reduce influence of dust or the like entering through the hole330aon the semiconductor chip51. Moreover, with such disposition, for example, the sensor310acan stably operate without the cap530of the sensor310a,which leads to cost reduction.

In the present embodiment, for example, as illustrated inFIG.6, the semiconductor chip51of the sensor310ais positioned between the package500and the substrate300when housed in the package500. Even when dust or the like enters inside the housing space S10, the dust is unlikely to move upward from the substrate300side (lower side) and affect the semiconductor chip51. Thus, the pressure sensor apparatus18can measure absolute pressure in the housing space S10without influence of dust or the like.

FIG.7Ais an exploded perspective view of a pressure sensor apparatus19,FIG.7Bis a diagram for description of a first member401and a second member402, andFIG.7Cis a plan view of the pressure sensor apparatus19.FIG.7Dis a partial cross-sectional view along line G-G inFIG.7C, andFIG.7Eis a partial cross-sectional view along line H-H inFIG.7C.

The pressure sensor apparatus19is an apparatus capable of measuring absolute pressure in four spaces and includes the substrate300, the screws302ato302f,the sensors310ato310d,a cover400, and a bonding agent410. The substrate300, the screws302ato302f,and the sensors310ato310dare the same as in the pressure sensor apparatus18, and thus the following description will be mainly made on the cover400and the bonding agent410. Although described later in detail, the bonding agent410has a predetermined shape inFIG.7A, for example, which illustrates a solid state of the bonding agent410that is liquid.

The cover400is attached to the upside surface of the substrate300from above to form housing spaces S20to S23(described later in detail) in which the respective sensors310ato310dare housed. The cover400is configured to include first members401ato401dhaving hollow spaces, the second member402, coupling parts403ato403dand404ato404d,and introduction pipes421ato421d.

The “housing space S20” is a space surrounded by the inside of the first member401a,the bonding agent410(described later), and the substrate300, and the “housing space S21” is a space surrounded by the inside of the first member401b,the bonding agent410, and the substrate300. The “housing space S22” is a space surrounded by the inside of the first member401c,the bonding agent410, and the substrate300, and the “housing space S23” is a space surrounded by the inside of the first member401d,the bonding agent410, and the substrate300.

The first member401ais a member covering the sensor310adisposed on the substrate300and providing the housing space S20in which the sensor310ais housed (that is, a member having a hollow space inside) (refer toFIG.7B, for example). Similarly to the first member401a,the first members401bto401dare members providing the housing spaces S21to S23in which the sensors310bto310dare housed, respectively.

The second member402is a member having a substantially rectangular parallelepiped shape and formed with an opening surrounding the first members401ato401dat a central part in a plan view. The introduction pipes421ato421dare provided at the side surface of the second member402on the front side so that the housing spaces S20to S23communicate with the outside.

The introduction pipe421ais formed with a hole430acommunicating with the housing space S20. Similarly to the introduction pipe421a,the introduction pipes421bto421dare formed with holes430bto430dcommunicating with the housing spaces S21to S23, respectively. The screw holes322ato322fcorresponding to the respective screws302ato302fare provided at the back surface of the second member402.

The coupling part403ais a member coupling the first member401aand the second member402at the surface of the first member401aon the front side. The coupling part404ais a member coupling the first member401aand the second member402at the surface of the first member401aon the back side. The coupling part403ahas a tubular shape communicating with the hole430aof the introduction pipe421a.Accordingly, the coupling part403acorresponds to the introduction pipe421asubstantially.

Although not illustrated for convenience, the coupling parts403bto403dare the same as the coupling part403a,and the coupling parts404bto404dare the same as the coupling part404a.Specifically, the coupling parts403band404bcouple the first member401band the second member402, the coupling parts403cand404ccouple the first member401cand the second member402, and the coupling parts403dand404dcouple the first member401dand the second member402. Hereinafter, the four coupling parts403ato403dare also collectively referred to as a coupling part403, and the four coupling parts404ato404dare also collectively referred to as a coupling part404. The coupling part403of the present embodiment corresponds to a “pipe”.

Similarly to the above-described pressure sensor apparatus17inFIGS.4A to4C, the pressure sensor apparatus19has a gap between the first members401ato401dand the second member402. In the present embodiment, the bonding agent410filling (gap) between each of the first members401ato401dand the second member402can eliminate the gap between each of the first members401ato401dand the second member402. Similarly to the above-described bonding agent205, the bonding agent410of the present embodiment is, for example, a potting material of silicon resin.

In the present embodiment, the coupling parts403and404are provided at positions separated from the substrate300when the cover400is attached to the substrate300. Accordingly, the bonding agent410can reliably eliminate the gap between each of the four first members401ato401dand the second member402. In this manner, the bonding agent410of the present embodiment shields the inside of the housing spaces S20to S23from the outside so that the housing spaces S20to S23are sealed when the holes430ato430dare blocked.

As inFIG.1A, a tube (not illustrated) is attached to each of the introduction pipes421ato421dof the cover400of the pressure sensor apparatus19. In the present embodiment, the cover400directly contacts the substrate300but does not directly contact the sensors310ato310d.Thus, force is not directly applied to the sensors310ato310dthrough the cover400, and accordingly, the pressure sensor apparatus19of the present embodiment can accurately measure absolute pressure in the housing spaces S20to23.

In the pressure sensor apparatus19, as illustrated inFIG.7E, the sensor310ais disposed such that the semiconductor chip51is not positioned on an extended line of a central axis A1of the hole430a(in this example, the central axis of an opening part of the introduction pipe421aformed with the hole430a). Accordingly, it is possible to reduce influence of dust or the like entering through the hole430aon the semiconductor chip51. Moreover, with such disposition, for example, the sensor310acan stably operate without the cap530of the sensor310a,which leads to cost reduction.

<<Another Embodiment of Pressure Sensor Apparatus15>>

Although the cap34is provided in the sensor21illustrated inFIG.2, a tube is attached to an introduction pipe of a cover in a case where the sensor21is applied to the pressure sensor apparatuses15to17, and thus the cap34does not necessarily need to be provided. For example, a sensor22without the cap34may be employed as illustrated inFIG.8.

FIG.9is an example of a partial cross-sectional view of the pressure sensor apparatus15including the sensor22without the cap34. InFIG.9, the position of the introduction pipe112is changed to an end part (for example, an end part on the left side) of the ceiling part111such that the semiconductor chip51is not positioned on an extended line of a central axis A2of the hole120(central axis of an opening part of the introduction pipe112formed with the hole120). Thus, even when dust or the like enters the housing space S2through the hole120of the pressure sensor apparatus15illustrated inFIG.9, the dust is unlikely to directly contact the measurement unit31(the semiconductor chip51, in particular).

In this manner, degradation of the measurement accuracy can be prevented since the position of the introduction pipe112is changed to an end part (for example, the end part on the left side) of the ceiling part111such that the semiconductor chip51is not positioned on the extended line of the central axis A2of the hole120.

The above description is made on an example of the sensor22without the cap34for convenience but is also applicable to the sensor21inFIG.3B. With omission of the cap34, cost reduction can be achieved for the sensor22as compared to the sensor21.

Summary

The pressure sensor apparatuses15to19of the present embodiment are described above. For example, in the pressure sensor apparatus15illustrated inFIG.3B, a tube is attached to the introduction pipe112of the cover110a.In such an embodiment, when the tube is attached to the cover110a,force is not directly applied to the sensor21in the housing space S2from the cover110a.Thus, the pressure sensor apparatus15can prevent degradation of the measurement accuracy of the sensor21.

As described for the pressure sensor apparatuses15and16, for example, the bonding agent122and the O ring126can be provided as a “seal”. With such a seal, the housing spaces S2and S3can be sealed.

For example, in the cover110aof the pressure sensor apparatus15, the attachment parts114are provided outside the wall part113a.With such attachment parts114, the cover110acan be easily attached to the substrate100.

As illustrated inFIG.3B, the openings101are formed on the substrate100, and the screw holes121are formed in the attachment parts114. The cover110aand the substrate100are fixed by using the screws150corresponding to the openings101and the screw holes121.

In the pressure sensor apparatus15, each slit115is formed between the wall part113aand the corresponding attachment part114. Accordingly, force can be prevented from being conveyed to the sensor21side when the cover110ais attached to the substrate100by the screws150, and thus degradation of the measurement accuracy of the sensor21can be prevented.

The pressure sensor apparatus17includes the first member200, the second member201surrounding the first member, and the coupling parts202ato202dcoupling the first member200and the second member201. With such a configuration, the housing space S4in which the sensor21is housed can be formed by filling the gap between the first member200and the second member201with the bonding agent205(in this example, a potting material). In such a pressure sensor apparatus17, as well, force is not directly applied to the sensor21in the housing space S4from the cover140when a tube is attached to the cover140. Thus, the pressure sensor apparatus17can prevent degradation of the measurement accuracy of the sensor21.

In the pressure sensor apparatus17, the attachment parts203are provided outside the second member201. With such attachment parts203, the cover140can be easily attached to the substrate100.

The cover140is attached to the substrate100by using the screws150corresponding to the screw holes231of the attachment parts203.

In the pressure sensor apparatus17, each slit204is formed between the second member201and the corresponding attachment part203. Accordingly, force can be prevented from being conveyed to the sensor21side when the cover140is attached to the substrate100by the screws150, and thus degradation of the measurement accuracy of the sensor21can be prevented.

For example, in the pressure sensor apparatus19illustrated inFIG.7D, the coupling part403ais part of the introduction pipe421a.With such a coupling part403a,the first member401aand the second member402can be reliably coupled to each other and the housing space S20can communicate with the outside.

For example, as illustrated inFIGS.5E,7E, and9, the semiconductor chip51is not positioned on the extended lines of the axes A0to A2in the present embodiment. With this configuration, it is possible to reduce influence of dust or the like on the semiconductor chip51.

In the sensor310aillustrated inFIG.6, for example, the package500in which the semiconductor chip51is housed is positioned on the upper side of the semiconductor chip51, and the substrate300to which the sensor310ais attached is positioned on the lower side of the semiconductor chip51. In other words, the semiconductor chip51is positioned between the package500and the substrate300in the present embodiment. With this configuration, it is possible to lower the probability of influence of dust or the like on the semiconductor chip51even in a case where no cap is provided.

In the pressure sensor apparatus18, the shield member350includes the part352common to the parts351aand351b.Thus, space saving is possible even in a case where a plurality of sensors310are disposed on the substrate300.

The present disclosure is made in view of the conventional problem as described above and intended to provide a pressure sensor apparatus capable of reducing degradation of the accuracy of pressure measurement.

According to the present disclosure, it is possible to provide a pressure sensor apparatus capable of reducing degradation of the accuracy of pressure measurement.

Embodiments of the present disclosure described above are simply to facilitate understanding of the present disclosure and are not in any way to be construed as limiting the present disclosure. The present disclosure may variously be changed or altered without departing from its essential features and encompass equivalents thereof.