JP2015200581A - Pressure detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure detection device that suppresses unevenness of a stress distribution of a housing and can obtain excellent air-tightness and sensor sensitivity.SOLUTION: A pressure detection device 10 according to the present invention comprises: a housing 21 that has a cavity 23 formed; a pressure sensor 15 that is installed in the cavity 23; and a lead frame 31 that is embedded in the housing 21. The lead frame 31 has: a top part lead frame 31a that is exposed inside the cavity 23 to be electrically connected to the pressure sensor 15; a connection part 31d that extends toward a thickness direction of the housing 21; and an exposed part 31e that is exposed from a bottom surface 21b of the housing 21, and the exposed part 31e is configured to be flush with the bottom surface 21b of the housing 21.

Description

  The present invention relates to a pressure detection device, and more particularly to a pressure detection device in which a pressure sensor is installed in a housing.

  Patent Document 1 listed below discloses an invention related to a pressure detection device (described as a pressure sensor package in Patent Document 1) having high lead frame positional accuracy and waterproof performance. 13A is a bottom view of a conventional pressure detection device described in Patent Document 1, and FIG. 13B is a cross-sectional view taken along line XIII-XIII in FIG. 13A. It is sectional drawing of a pressure detection apparatus when it sees from.

  As shown in FIG. 13B, the pressure detection device 110 of the conventional example includes a pressure sensor 115 that detects pressure, a housing 121 that houses the pressure sensor 115, and a lead frame that is electrically connected to the pressure sensor 115. 131. A cavity 123 is formed in the housing 121, and a pressure sensor 115 is installed in the cavity 123.

  The lead frame 131 is exposed to the cavity 123 at the inner end 131 a and is electrically connected to the pressure sensor 115 via the bonding wire 117. The lead frame 131 is bent from the inner end 131a to the bottom surface 121b side of the housing 121 and is provided so as to protrude from the bottom surface 121b. As shown in FIG. 13A, the outer end portion 131b of the lead frame 131 protruding from the bottom surface 121b is bent in the outer peripheral direction of the bottom surface 121b to form an extending portion 131c.

  In the pressure detection device 110 of the conventional example, the housing 121 is formed integrally with the lead frame 131 using a resin material. Therefore, since the periphery of the connecting portion 131d that connects the inner end portion 131a and the outer end portion 131b is filled with the resin constituting the housing 121, the waterproof performance of the pressure detection device 110 of the conventional example can be improved.

Republished patent WO2010 / 016439

  FIG. 14 is a schematic cross-sectional view for explaining the problem of the pressure detection device of the conventional example, and FIG. 14A is a schematic cross-sectional view when viewed from the X1-X2 direction of FIG. 14 (b) is a schematic cross-sectional view when viewed from the Y1-Y2 direction of FIG. 13 (a). 14 is a schematic cross-sectional view when the pressure detection device 110 is incorporated in an electronic device such as a smartphone, a camera, or a watch.

  As shown in FIGS. 14A and 14B, the pressure detection device 110 is placed on the support member 141, and the bottom surface 121 b of the housing 121 is in contact with the support member 141. A housing 151 such as an electronic device is provided on the upper surface 121 a of the housing 121 via an O-ring 146, and airtightness between the housing 151 and the housing 121 is ensured.

  As shown in FIGS. 14A and 14B, in the pressure detecting device 110 of the conventional example, the lead frame 131 is provided with an extending portion 131c that protrudes from the bottom surface 121b of the housing 121 and is bent in the outer peripheral direction. For this reason, as shown in FIG. 14B, a relief portion 143 is provided in the support member 141 where the lead frame 131 is provided, and the bottom surface 121 b of the housing 121 and the lead frame 131 are provided on the support member 141. It has a structure that does not come into contact. On the other hand, the lead frame 131 does not come into contact with the support member 141 by the escape portion 143, so that the bottom surface 121b of the housing 121 is placed on the support member 141 at a location where the lead frame 131 is not provided as shown in FIG. Abutted.

  Therefore, when the pressure detection device 110 is incorporated in an external electronic device or the like and pressure is applied to the cavity 123, the stress distribution of the housing 121 is different between a portion where the support member 141 contacts the bottom surface 121b and a portion where the support member 141 does not contact. Non-uniformity occurs. For this reason, the housing 121 is distorted due to the non-uniform stress distribution, and the sensor output of the pressure sensor 115 fluctuates. Further, the lead frame 131 is not in contact with the support member 141 at the location where the relief portion 143 is provided, and deformation is likely to occur on the upper surface 121a of the housing 121. There is a problem that sufficient stress is not applied to the ring 146 and it is difficult to ensure airtightness.

  An object of the present invention is to solve the above-mentioned problems and to provide a pressure detection device capable of suppressing the non-uniformity of the stress distribution of the housing and obtaining good airtightness and sensor sensitivity.

  The pressure detection device according to the present invention includes a housing in which a cavity is formed, a pressure sensor installed in the cavity, and a lead frame embedded in the housing, and the lead frame is exposed inside the cavity. An upper lead frame electrically connected to the pressure sensor, a connection portion extending in a thickness direction of the housing, and an exposed portion exposed from the bottom surface of the housing, wherein the exposed portion is the housing It constitutes the same plane as the bottom surface.

  According to this, since the lead frame constitutes the same plane as the bottom surface of the housing, when the pressure detection device is incorporated into an external electronic device, the support member is applied to the bottom surface of the housing and the lead frame constituting the same plane. It can be supported by contact. Therefore, nonuniformity of the stress distribution generated in the housing can be suppressed, and the occurrence of distortion of the housing can be suppressed to reduce the output fluctuation of the pressure sensor. Further, since the distortion of the housing can be reduced, the airtightness between the housing of the external electronic device and the housing can be ensured.

  Therefore, according to the pressure detection device of the present embodiment, it is possible to suppress the non-uniformity of the stress distribution of the housing and obtain good airtightness and sensor sensitivity.

  It is preferable that the outer periphery of the bottom surface of the housing is a contact surface that is in contact with an external support member, and the bottom surface and the lead frame form the same plane on the contact surface. According to this, the support member is brought into contact with the outer periphery of the bottom surface of the housing, and the external support member is provided at a position where it does not overlap with the pressure sensor. This can be prevented and output fluctuation of the pressure sensor can be reduced.

  Preferably, the exposed portion includes a protruding portion that protrudes from the bottom surface, and a flat portion that forms the same plane as the bottom surface on the outer peripheral side of the bottom surface with respect to the protruding portion. According to this, since the bottom surface of the housing and the flat portion of the lead frame constitute the same plane and come into contact with the external support member, unevenness in the stress distribution of the housing is suppressed. Further, when solder joining the lead frame and the external wiring board, a solder fillet is easily formed over the side surface of the protruding portion, and the joining strength is increased.

  It is preferable that a concave portion is provided on the bottom surface of the housing, and a side surface of the protruding portion is exposed in the concave portion. The recess is formed to fix the lead frame in the molding die when the lead frame and the housing are integrally molded with resin, and can be formed by positioning the lead frame with certainty. Moreover, since the side surface of the protrusion is exposed in the recess, the bonding area when connecting to the external wiring board is increased, and the bonding strength can be improved.

  It is preferable that a wiring board is connected to the protruding portion of the lead frame. According to this, when solder-bonding the protruding portion of the lead frame and the wiring board, a solder fillet is easily formed over the side surface of the protruding portion, and the bonding strength is increased.

  The housing is preferably resin-molded integrally with the lead frame using a thermoplastic resin. According to this, by arranging the lead frame in the molding die and performing resin molding, the lead frame and the bottom surface of the housing can surely form the same plane.

  Preferably, the exposed portion is bent in the same direction as the upper lead frame exposed in the cavity. According to this, the position accuracy of the lead frame can be improved, and the leak path (gap) that is formed between the embedded lead frame and the housing and connects the bottom surface of the housing and the cavity is lengthened, and the pressure introducing portion It is possible to suppress the ingress of gas from other than the above and improve the sensor sensitivity.

  The connecting portion is preferably bent in a direction intersecting the thickness direction of the housing. According to this, since the leak path (gap) between the connection part embedded in the housing and the housing can be made longer, the ingress of gas from other than the pressure introducing part can be suppressed.

  Preferably, the exposed portion is bent in a direction opposite to the upper lead frame exposed in the cavity. According to this, it is possible to reduce the number of portions to be bent in the exposed portion of the lead frame, and it can be easily manufactured.

  According to the pressure detection device of the present invention, it is possible to suppress the non-uniformity of the stress distribution in the housing and obtain good airtightness and sensor sensitivity.

1 is a perspective view of a pressure detection device according to a first embodiment of the present invention. It is a top view of the pressure detection apparatus of this embodiment. It is a bottom view of the pressure detection apparatus of this embodiment. It is sectional drawing of a pressure detection apparatus when it cut | disconnects by the IV-IV line | wire of FIG. 3, and it sees from the arrow direction. It is sectional drawing of a pressure detection apparatus when it cut | disconnects by the VV line | wire of FIG. 3, and it sees from the arrow direction. It is sectional drawing when the pressure detection apparatus of this embodiment is integrated in an electronic device. It is a partial expanded sectional view when a wiring board is connected to a pressure detection apparatus. The pressure detection apparatus in 2nd Embodiment is shown, (a) It is sectional drawing when cut | disconnecting in the same location as the IV-IV line of FIG. 3, (b) It cut | disconnects in the same location as the VV line of FIG. It is sectional drawing when doing. It is sectional drawing of the pressure detection apparatus in 3rd Embodiment. It is explanatory drawing which shows the simulation result of the displacement amount distribution of a housing when a pressure is applied to a pressure detection apparatus, (a) The perspective view of the pressure detection apparatus of an Example, (b) The pressure detection apparatus of a comparative example It is a perspective view. It is explanatory drawing which shows the simulation result of the displacement amount distribution of a housing when a pressure is applied to a pressure detection apparatus, (a) The top view of the pressure detection apparatus of an Example, (b) The pressure detection apparatus of a comparative example It is a top view. It is a perspective view of the pressure detection apparatus of a comparative example. (A) It is a bottom view of the pressure detector of a prior art example, (b) It is a schematic cross section when cut | disconnected by the XIII-XIII line | wire of Fig.13 (a) and seeing from the arrow direction. FIG. 14A is a schematic cross-sectional view for explaining the problem of the pressure detection device of the conventional example, and FIG. 14A is a schematic cross-sectional view when viewed from the X1-X2 direction of FIG. FIG. 13B is a schematic cross-sectional view when viewed from the Y1-Y2 direction in FIG.

  Hereinafter, a pressure detection device according to a specific embodiment will be described with reference to the drawings. In addition, the dimension of each drawing is changed and shown suitably.

<First Embodiment>
FIG. 1 is a perspective view of a pressure detection device according to the first embodiment. FIG. 2 is a top view of the pressure detection device, and FIG. 3 is a bottom view of the pressure detection device. FIG. 4 is a cross-sectional view of the pressure detection device as viewed from the direction of the arrow cut along the line IV-IV in FIG. FIG. 5 is a cross-sectional view seen from a direction different from FIG. 4, and is a cross-sectional view of the pressure detection device as seen from the direction of the arrow cut along line VV in FIG. 3.

  As shown in FIG. 1, the pressure detection device 10 according to the present embodiment includes a housing 21 in which a cavity 23 is formed, a pressure sensor 15 installed in the cavity 23, and is embedded in the housing 21 and exposed in the cavity 23. A lead frame 31.

  In the present embodiment, the housing 21 is formed by resin molding using a thermoplastic resin. As the thermoplastic resin, for example, a liquid crystal polymer (Liquid Crystal Polymer, LCP), polyphenylene sulfide (PPS), polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), or the like can be used.

  As shown in FIGS. 4 and 5, the cavity 23 formed in the housing 21 includes a pressure introduction recess 24 and a pressure sensor storage recess 25 in order in the depth direction. A pressure sensor 15 is installed on the bottom surface of the pressure sensor housing recess 25, and a potting resin 16 is provided in the pressure introduction recess 24 so as to cover the pressure sensor 15. The potting resin 16 is a gel-like viscoelastic body, and for example, a silicone resin or a fluororesin is used.

  As shown in FIG. 2, the pressure sensor storage recess 25 has a substantially rectangular shape corresponding to the outer shape of the pressure sensor 15, and the pressure introduction recess 24 has a diagonal length of the pressure sensor storage recess 25 as one side. The plane is substantially rectangular in size. The pressure introducing recess 24 and the pressure sensor housing recess 25 are formed with a phase difference of 45 °. Thereby, an external pressure can be introduced from the pressure introducing recess 24, and the bonding wire 17 and the pressure sensor 15 are connected to the potting resin 16 by making the space of the pressure sensor receiving recess 25 smaller than the pressure introducing recess 24. Can be reliably covered.

  The pressure sensor 15 has a MEMS (Micro Electro Mechanical System) structure, and includes a diaphragm portion that receives pressure and a strain detection element that detects deformation of the diaphragm portion. For example, a piezoresistive element can be used as the strain sensing element, and the strain sensing element is provided around the diaphragm portion. The diaphragm portion is deformed according to the pressure applied to the potting resin 16 in the pressure introducing recess 24, and the resistance of the piezoresistive element changes. Based on this resistance change, the pressure applied to the pressure detection device 10 can be detected.

  As shown in FIG. 4, the lead frame 31 includes an upper lead frame 31a exposed inside the cavity 23 and electrically connected to the pressure sensor 15, a connection portion 31d extending in the thickness direction of the housing 21, and a housing. And an exposed portion 31e exposed from the bottom surface 21b of the structure 21. The upper lead frame 31 a is bent from the outer peripheral side of the housing 21 toward the pressure sensor housing recess 25. The upper lead frame 31 a is provided to be exposed in the pressure introducing recess 24, and the exposed upper lead frame 31 a and the pressure sensor 15 are connected by the bonding wire 17. As shown in FIG. 2, the upper lead frame 31 a is exposed at each corner of the pressure introducing recess 24. As described above, the lead frame 31 is exposed to the inside of the cavity 23 and is electrically connected to the pressure sensor 15, and the detection signal of the pressure sensor 15 is transmitted to the external circuit via the lead frame 31.

  Further, as shown in FIG. 4, the connection portion 31 d bent from the upper lead frame 31 a at the first bent portion 31 p extends in the thickness direction of the housing 21 and is exposed from the bottom surface 21 b of the housing 21. The lead frame 31 exposed on the bottom surface 21b is bent at the second bent portion 31q in the same direction as the upper lead frame 31a, so that a protruding portion 31b protruding from the bottom surface 21b of the housing 21 is formed. In the present embodiment, the lead frame 31 is integrally molded with the housing 21, and the periphery of the connection portion 31d that connects the upper lead frame 31a and the protruding portion 31b and the upper lead frame 31a and the protruding portion 31b is as follows. The housing 21 is filled with a resin material.

  Further, as shown in FIG. 4, since the protruding portion 31b is provided in the same direction as the upper lead frame 31a, the protruding portion 31b can be fixed by being sandwiched in the vertical direction during resin molding. Can be improved.

  As shown in FIG. 3, when the housing 21 is viewed from the bottom surface 21b side, the protruding portion 31b is bent by about 90 ° in the outer peripheral direction from the center side of the bottom surface 21b at the third bent portion 33r. A plurality of lead frames 31 are provided on the bottom surface 21b, and extend from the center side of the bottom surface 21b to the outer peripheral side in different directions.

  In the pressure detection device 10 of the present embodiment, as shown in FIG. 5, the exposed portion 31 e exposed on the bottom surface 21 b includes a protruding portion 31 b protruding from the bottom surface 21 b and a bottom surface on the outer peripheral side of the bottom surface 21 b relative to the protruding portion 31 b. 21b and the flat part 31c which comprises the same plane. The flat portion 31c is formed continuously with the protruding portion 31b, and is bent by forming a step with the protruding portion 31b so as to be recessed in the thickness direction of the housing 21 with respect to the protruding portion 31b at the fourth bent portion 31s. Extend in the direction. In addition, as shown in FIG. 5, the connection part 31d of the lead frame 31 is bent by the fifth bent part 31t in a direction orthogonal to the thickness direction of the housing 21, thereby further increasing the leak path and improving the airtightness. improves.

  As shown in FIG. 3, in each lead frame 31, a protruding portion 31b protruding outward from the bottom surface 21b is formed on the center side of the bottom surface 21b, and on the outer peripheral side of the bottom surface 21b from the protruding portion 31b. The flat portion 31c and the bottom surface 21b constitute the same plane. Thereby, in the bottom face 21b of the housing 21, the flat surface which does not have a part which goes around the outer periphery and protrudes from the bottom face 21b is formed. Therefore, when the pressure detection device 10 is incorporated into an electronic device, the outer periphery of the bottom surface 21b of the housing 21 can be brought into contact with an external support member as the contact surface 21c.

  FIG. 6 is a cross-sectional view when the pressure detection device of this embodiment is incorporated into an electronic apparatus. As shown in FIG. 6, a protruding wall portion 21 d is formed on the upper surface 21 a of the housing 21, and the wall portion 21 d is formed surrounding the cavity 23 as shown in FIG. 2. As shown in FIG. 6, the pressure detection device 10 is disposed with the upper surface 21 a of the housing 21 facing the housing 45 of the electronic device, and stress is applied to an O-ring 46 provided between the upper surface 21 a and the housing 45. The pressure detection device 10 is fixed so as to be pressed. Thereby, the airtightness between the pressure detection apparatus 10 and an electronic device can be ensured, and a pressure can be detected favorably.

  Further, as shown in FIG. 6, a support member 41 that supports the pressure detection device 10 is provided on the bottom surface 21 b side of the housing 21. The support member 41 is formed in a hollow cylindrical shape, and the upper surface of the support member 41 is in contact with and supported by the bottom surface 21 b of the housing 21 and the flat portion 31 c of the lead frame 31. Further, the protruding portion 31 b of the lead frame 31 is located in a space surrounded by the support member 41. As shown in FIG. 3, the outer periphery of the bottom surface 21b of the housing 21 is an abutting surface 21c that abuts against an external support member 41, and the bottom surface 21b and the lead frame 31 are flush with each other on the abutting surface 21c. It is composed.

  According to the pressure detection device 10 of the present embodiment, since the lead frame 31 is provided in the same plane as the bottom surface 21b of the housing 21, the same plane is provided when the pressure detection device 10 is incorporated in an external electronic device. The support member 41 can be brought into contact with and supported by the bottom surface 21 b of the housing 21 and the lead frame 31. Therefore, unlike the conventional pressure detection device 110 shown in FIG. 14, the upper surface of the support member 41 can be formed flat and supported without forming the relief portion 143 in the support member 141. The support member 41 can be brought into contact with the outer periphery of the bottom surface 21b without any gap. Therefore, the nonuniformity of the stress distribution generated in the housing 21 can be suppressed, the distortion of the housing 21 can be suppressed, and the output fluctuation of the pressure sensor 15 can be reduced.

  In addition, since unevenness of the stress distribution generated in the housing 21 can be suppressed, distortion is reduced over the entire circumference of the upper surface 21a of the housing 21, and the housing 45 of the external electronic device and the housing 21 are reduced. Airtightness can be ensured.

  Therefore, according to the pressure detection device 10 of the present embodiment, it is possible to suppress uneven stress distribution in the housing 21 and obtain good airtightness and sensor sensitivity.

  Further, as shown in FIG. 6, the support member 41 is brought into contact with the contact surface 21 c on the outer periphery of the bottom surface 21 b at a position overlapping the O-ring 46. Therefore, since the O-ring 46 and the support member 41 are provided at a position that does not overlap with the pressure sensor 15, it is possible to prevent stress when being incorporated into an external electronic device from being directly applied to the pressure sensor 15 and to output the pressure sensor 15. Variation can be reduced.

  In the present embodiment, “comprising the same plane” desirably means that the lead frame 31 and the bottom surface 21b of the housing 21 are continuous in a flat state without a step, but is not limited thereto. For example, the lead frame 31 and the bottom surface 21b of the housing 21 may be formed due to an installation error of the lead frame 31 when the lead frame 31 and the housing 21 are integrally molded with resin or due to shrinkage or deformation of the resin material constituting the housing 21. Even if a slight step is formed, the same effect can be obtained.

  FIG. 7 is a partially enlarged cross-sectional view when a wiring board is connected to the pressure detection device. In the present embodiment, a wiring board 51 such as a printed board or a flexible printed board is used. As shown in FIG. 7, the wiring substrate 51 includes a substrate 52, a wiring 53 formed on the substrate 52, and a protective layer 54 that protects the wiring 53. The substrate 52 is formed using, for example, polyimide resin, glass epoxy resin, or the like, and the wiring 53 is formed by stacking a plurality of layers of metal materials such as Cu, alloy materials such as CuNi, or the like. The protective layer 54 is a solder resist or a cover film, and is formed on the wiring 53 other than the connection portion.

  In the present embodiment, the wiring 53 of the wiring substrate 51 and the protruding portion 31 b of the lead frame 31 are joined using the solder 56. Thereby, as shown in FIG. 7, it becomes easy to form a solder fillet over the side surface of the protrusion 31b, and the bonding strength is increased.

  As shown in FIG. 7, a recess 22 is provided on the bottom surface 21 b of the housing 21, and the side surface of the protruding portion 31 b is exposed in the recess 22. The recess 22 is formed by holding the lead frame 31 in a molding die when the lead frame 31 and the housing 21 are integrally molded with resin, thereby positioning the lead frame 31 reliably. can do. Further, as shown in FIG. 7, the side surface of the protrusion 31 b is exposed in the recess 22, and a solder fillet can be formed in the recess 22, so that the solder joint area when connecting to the wiring board 51 is increased. As a result, the bonding strength can be improved.

<Second Embodiment>
FIG. 8 shows a pressure detection device according to the second embodiment. FIG. 8A is a cross-sectional view taken along the line IV-IV in FIG. 3, and FIG. It is sectional drawing when it cut | disconnects in the same location as the VV line | wire of 3. FIG.

  As shown in FIG. 8, the pressure detection device 11 of the present embodiment is different in the structure of the lead frame 31 exposed from the bottom surface 21 b of the housing 21, and the other configuration is the same as that of the first embodiment. In the present embodiment, the lead frame 31 exposed from the bottom surface 21 b is not provided with the protruding portion 31 b, and the flat portion 31 c and the bottom surface 21 b of the lead frame 31 form the same plane on the entire bottom surface 21 b of the housing 21. ing.

  Even if it is such an aspect, when incorporating the pressure detection apparatus 11 in an electronic device, the support member 41 can be brought into contact with and supported by the bottom surface 21b of the housing 21 and the lead frame 31 that constitute the same plane. Therefore, nonuniformity of the stress distribution generated in the housing 21 can be suppressed, and the occurrence of distortion of the housing 21 can be suppressed to reduce the output fluctuation of the pressure sensor 15. Moreover, since the distortion of the housing 21 can be reduced, the airtightness between the housing 45 of the external electronic device and the housing 21 can be ensured.

  Further, since the protruding portion 31 b is not provided, the support member 41 other than the cylindrical shape can be used, and the degree of freedom of the shape of the upper surface of the support member 41 and the position of the joint portion with the wiring board 51 can be improved. it can.

<Third Embodiment>
In the pressure detection device 10 of the first embodiment and the pressure detection device 11 of the second embodiment, the upper lead frame 31a exposed to the cavity 23 and the protruding portion 31b protruding from the bottom surface 21b are opposed to each other. Although it is bent and formed into a U-shaped cross section, it is not limited to this. FIG. 9 is a cross-sectional view of the pressure detection device of the third embodiment. As shown in FIG. 9, the lead frames 31 exposed from the inside of the housing 21 to the bottom surface 21 b are bent in the outer peripheral direction of the housing 21 to form protruding portions 31 b. Furthermore, the flat part 31c which comprises the same plane as the bottom face 21b is formed in the outer peripheral side rather than the protrusion part 31b.

  Also in such an embodiment, the protruding portion 31b can be connected to the wiring board 51 (not shown), and solder fillets are easily formed on the side surface of the protruding portion 31b, thereby increasing the bonding strength. Further, since the flat portion 31c is provided on the outer periphery of the bottom surface 21b of the housing 21 so as to form the same plane as the bottom surface 21b, the support member 41 (not shown) is brought into contact with the outer periphery of the bottom surface 21b of the housing 21. Can be made. Therefore, the nonuniformity of the stress distribution generated in the housing 21 can be suppressed, the distortion of the housing 21 can be suppressed, and the output fluctuation of the pressure sensor 15 can be reduced.

  In the present embodiment, the protruding portion 31 b is formed on the outer peripheral side of the housing 21 with respect to the pressure sensor housing recess 25. For this reason, it can relieve | moderate that the stress at the time of a solder connection is directly applied to the pressure sensor storage recessed part 25, and can reduce the output fluctuation | variation of the pressure sensor 15. FIG. Further, compared with the first embodiment, the number of bent portions (third bent portion 31r) of the lead frame 31 is reduced, and the lead frame 31 can be easily manufactured.

<Example>
10 and 11 are explanatory diagrams illustrating simulation results of the displacement distribution of the housing when a pressure is applied to the pressure detection device. FIG. 10A is a perspective view of the pressure detection device of the embodiment, and FIG. 10B is a perspective view of the pressure detection device of the comparative example. FIG. 11A is a top view of the pressure detection device of the embodiment, and FIG. 10B is a top view of the pressure detection device of the comparative example.

  The pressure detection device of this example has the same configuration as that of the first embodiment shown in FIGS. 1 to 5. FIG. 12 shows a perspective view of a pressure detection device of a comparative example. The pressure detection device 210 of the comparative example shown in FIG. 12 is different in the configuration in which the lead frame 231 protrudes from the bottom surface 221b on the outer periphery of the bottom surface 221b of the housing 221.

  The simulation results of the displacement distribution shown in FIG. 10 and FIG. 11 show the thickness direction of the housing 21 when a pressure of 60 atm is applied to the pressure introducing recess 24 with the pressure detection device 10 incorporated in an electronic device. The displacement distribution is shown. As shown in FIG. 1, pressure is applied to the pressure detection device 10 of the embodiment in contact with a support member 41 having a flat upper surface, and the pressure detection device 210 of the comparative example is shown in FIG. As shown, the pressure is applied in a state of being in contact with the support member 241 provided with the escape portion 243.

  As shown in FIG. 10A, in the pressure detection device 10 of the embodiment, the displacement amount of the housing 21 is small, and the displacement amount is uniformly distributed on the outer periphery of the housing 21. Therefore, the amount of displacement on the upper surface 21a of the housing 21 is uniform, and airtightness between the housing 45 of the electronic device and the like can be ensured. As shown in FIG. 10B, in the pressure detection device 210 of the comparative example, the displacement amount of the housing 221 is large at the location where the relief portion 243 of the support member 241 is provided. This is because the lead frame 231 is not in contact with the support member 241 in the escape portion 243, and a gap is formed between the lead member 241 and the housing 221 to which pressure is applied is easily deformed. Because it is. Therefore, the distribution of the displacement amount on the upper surface 221a of the housing 221 is generated, and the airtightness between the housing of the electronic device and the like may be reduced.

  Moreover, as shown to Fig.11 (a), in the pressure detection apparatus 10 of an Example, the displacement amount of the bottom face of the pressure sensor storage recessed part 25 is restrained small, and the pressure sensor 15 (it abbreviate | omits and shows in FIG. 11). Variations in sensor output are reduced. On the other hand, in the pressure detection device 210 of the comparative example shown in FIG. 11B, the displacement amount increases on the outer periphery of the housing 221, and the displacement amount in the pressure sensor housing recess 225 also increases. For this reason, fluctuations in the sensor output of the pressure sensor 215 (not shown in FIG. 11) increase.

  As described above, according to the pressure detection device 10 of the present embodiment, the lead frame 31 is provided in the same plane as the bottom surface 21b of the housing 21, and thus the pressure detection device 10 is incorporated in an external electronic device. At this time, the support member 41 can be brought into contact with and supported by the bottom surface 21b of the housing 21 and the lead frame 31 constituting the same plane. Therefore, unlike the pressure detection device 210 of the comparative example shown in FIG. 12, the upper surface of the support member 41 can be formed flat and supported without forming the escape portion 243 in the support member 241. The support member 41 can be brought into contact with the outer periphery of the bottom surface 21b. Therefore, nonuniformity of the stress distribution generated in the housing 21 can be suppressed, distortion of the housing 21 can be suppressed, output fluctuation of the pressure sensor 15 can be reduced, and airtightness can be secured.

DESCRIPTION OF SYMBOLS 10, 11, 12 Pressure detection apparatus 15 Pressure sensor 21 Housing 21a Upper surface 21b Bottom surface 21c Contact surface 21d Wall part 22 Recess 23 Cavity 24 Pressure introduction recessed part 25 Pressure sensor accommodation recessed part 31 Lead frame 31a Upper lead frame 31b Protrusion part 31c Flat part 31d Connection portion 31e Exposed portion 31p First bent portion 31q Second bent portion 31r Third bent portion 31s Fourth bent portion 31t Fifth bent portion 41 Support member 45 Housing 51 Wiring substrate 53 Wiring 56 Solder

Claims (9)

A housing in which a cavity is formed, a pressure sensor installed in the cavity, and a lead frame embedded in the housing;
The lead frame includes an upper lead frame exposed inside the cavity and electrically connected to the pressure sensor, a connection portion extending in a thickness direction of the housing, and an exposed portion exposed from the bottom surface of the housing. Have
The pressure detecting device, wherein the exposed portion constitutes the same plane as the bottom surface of the housing.   The outer periphery of the bottom surface of the housing is a contact surface that comes into contact with an external support member, and the bottom surface and the lead frame form the same plane on the contact surface. Item 2. The pressure detection device according to Item 1.   The said exposed part has the protrusion part which protrudes from the said bottom face, and the flat part which comprises the same plane as the said bottom face in the outer peripheral side of the said bottom face from the said protrusion part. 2. The pressure detection device according to 2.   The pressure detecting device according to claim 3, wherein a concave portion is provided on the bottom surface of the housing, and a side surface of the protruding portion is exposed in the concave portion.   The pressure detection device according to claim 3, wherein a wiring board is connected to the protruding portion of the lead frame.   The pressure detection device according to claim 1, wherein the housing is resin-molded integrally with the lead frame using a thermoplastic resin.   The pressure detecting device according to claim 1, wherein the exposed portion is bent in the same direction as the upper lead frame exposed in the cavity.   The pressure detection device according to any one of claims 1 to 7, wherein the connection portion is bent in a direction intersecting with a thickness direction of the housing.   The pressure detecting device according to claim 1, wherein the exposed portion is bent in a direction opposite to the upper lead frame exposed in the cavity.