JP2012093111A - Sensor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection between cases with high sealability only by abutment between the cases.SOLUTION: A cover 3 is fitted to a base 1 in which a sensor module 7 is installed and fixed to form a housing 5. The base 1 has a fitting projection 15 provided along an outer peripheral edge thereof, and the cover 3 has a fitting groove 23 to which the fitting projection 15 is fitted. A protrusion 21 having a triangular cross-section is preliminarily formed at an end surface of the fitting projection 15. When the cover 3 is fitted to the base 1 to provide a connection between the cover 3 and the base 1, the protrusion 21 of the end surface of the fitting projection 15 is abutted to the bottom of the fitting groove 23, thereby being plastically deformed and crushed to form a seal portion S.

Description

  The present invention relates to a sensor device including a housing that houses a sensor chip.

  A housing for housing a sensor chip in a sensor device is usually configured by abutting and joining openings facing each other in a pair of cases. For example, in a pressure sensor that detects the pressure of a fluid, a diaphragm and a piezoresistive element that are formed into a thin film by processing a semiconductor substrate are accommodated in a housing as a package. For this reason, the housing requires a structure for preventing water and the like from entering inside.

  For example, in the pressure sensor described in Patent Document 1 below, a metal mounting pedestal serving as one case and a cylindrical member made of a crystalline last material or an amorphous material serving as the other case provided with a diaphragm are mutually connected. Bonded as a foreign material. At that time, a metal mounting base serving as one soft member is coupled with plastic deformation and elastic deformation by an annular protrusion at the tip formed on the other cylindrical member and an annular coupling groove on the outer peripheral surface.

JP 2005-106467 A

  By the way, the above-mentioned conventional one uses a mold because when a case is joined, a metal mounting base which is one soft member is plastically deformed and elastically deformed by a brittle material such as the other ceramic. Pressure. For this reason, it is difficult to combine the cases while simply sealing each other while improving the sealing performance between the cases.

  In view of the above, an object of the present invention is to make it possible to combine the cases while simply sealing the cases together while improving the sealing performance between the cases.

  According to a first aspect of the present invention, a housing that houses a sensor chip that detects a fluid pressure includes first and second cases made of resin that are fitted to face each other with their openings facing each other. When the first and second cases are abutted and fitted to at least one of the first and second cases, the seal portion is formed by being relatively pressed between the other case and plastically deformed. Protrusions are provided.

  2nd invention is a sensor apparatus of 1st invention, Comprising: The said protrusion protrudes toward the said abutting direction on the front end surface of the abutting direction of the said 1st, 2nd case. And

  3rd invention is a sensor apparatus of 2nd invention, Comprising: The said protrusion is a tapered shape, It is characterized by the above-mentioned.

  4th invention is the sensor apparatus of 1st invention, Comprising: The said 1st, 2nd case is each provided with the outer peripheral wall which stands up from the outer periphery of the bottom wall and the bottom wall, and said 1st, 2nd Any one of the outer peripheral walls of the case enters and fits inside the other outer peripheral wall, and the projections are formed on at least one of the one outer peripheral wall and the other outer peripheral wall facing each other. Is provided.

  5th invention is a sensor apparatus of 4th invention, Comprising: As for the said protrusion, the surface which opposes the abutting direction of the other case which abuts with respect to the case of the side which provided this protrusion, this tip is the side. The inclined surface is inclined so as to be in front of the abutting direction, and the surface opposite to the inclined surface is a vertical surface perpendicular to the abutting direction.

  According to the invention of claim 1, by causing the first and second cases to abut each other, the resin protrusion easily plastically deforms to become a seal portion. Bonding can be performed while improving the sealing property between each other.

  According to the invention of claim 2, when the cases are brought together, the projections are plastically deformed so as to be crushed in the abutting direction, so that the plastically deformed portions of the projections constituting the seal portion are hardly dispersed. , Sealability is further improved.

  According to the invention of claim 3, since the front end sides of the cases in the abutting direction are tapered, when the cases are abutted, the plastic deformation of the projections is facilitated by the tapered portion on the front end side in the abutting direction. Become.

  According to the invention of claim 4, compared with the case where the protrusion is set at the front end in the abutting direction of the one outer peripheral wall located inside, the intrusion of water or the like into the housing is more upstream than the infiltration direction. Can be suppressed on the side.

  According to the fifth aspect of the present invention, when the tip of the other case on the other side comes into contact with the inclined surface of the protrusion, the protrusion is easily plastically deformed and the fitting operation is facilitated.

It is sectional drawing of the sensor apparatus which shows the 1st Embodiment of this invention. (A) is a front view of the base of the housing in the sensor apparatus of FIG. 1, (b) is a front view of the case of the housing in the sensor apparatus. It is AA sectional drawing of Fig.2 (a). It is sectional drawing which shows the state which carried out the plastic deformation of the protrusion of FIG. It is sectional drawing which shows the internal structure of the sensor module in the sensor apparatus in which a housing shape differs a little from FIG. It is sectional drawing which shows the water penetration | invasion path | route with the sensor apparatus of FIG. It is sectional drawing which shows the modification which provided two protrusion with respect to FIG. FIG. 8 is a cross-sectional view showing a state where the two protrusions of FIG. 7 are plastically deformed. It is sectional drawing of the protrusion periphery formed in the housing in the sensor apparatus which shows the 2nd Embodiment of this invention, (a) is the state fitted with the base and case of the housing, (b) is the state before fitting, respectively. Show.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a cross-sectional view of a pressure sensor which is a sensor device showing a first embodiment of the present invention, and a base 1 shown in FIG. 2 (a) and a cover 3 shown in FIG. 2 (b) are fitted together. A housing 5 shown in FIG. 1 is configured, and a sensor module 7 serving as a sensor body is accommodated in the housing 5. The base 1 constitutes the first case and the cover 3 constitutes the second case, both of which are made of a plastically deformable resin.

  This sensor device can be applied to, for example, a water level sensor that is attached to a flow path of water (or hot water) in a hot water heater of a bathtub and detects the water level of the bathtub by the pressure in the flow path.

  The base 1 has an opening 9 on the side facing the cover 3, and the cover 3 also has an opening 11 on the side facing the base 1, and these bases 9, 11 face each other and face each other. 1 and the cover 3 are fitted and coupled.

  Further, the base 1 has a bottom wall 13, and a recess 13a is formed in the center of the bottom wall 13 as shown in FIG. 1, and the sensor module 7 is accommodated and fixed in the recess 13a. Details of the sensor module 7 will be described later.

  As shown in FIG. 2A, the base 1 has a rectangular shape that is long in the vertical direction in the figure, and has a fitting convex portion 15 formed on the outer peripheral edge excluding the lower portion. The fitting convex portion 15 constitutes an outer peripheral wall that rises from the outer peripheral edge of the bottom wall 13. Below the opening 11 where the fitting convex portion 15 is not formed is an open portion 19 for inserting a connector (not shown) connected to the terminal 17 drawn from the sensor module 7.

  And in this embodiment, as shown in FIG. 3 which is AA sectional drawing of Fig.2 (a) on the front end surface of the above-mentioned fitting convex part 15, as shown in FIG. It is integrally molded when molding. The protrusion 21 has a tapered cross-sectional triangular shape that is thinner toward the tip side, and is formed over the entire length of the fitting convex portion 15. In FIG. 2A, the protrusion 21 is shown as one line.

  In addition, what is shown with the code | symbol 22 which protrudes in FIG. 2 (a) on both the left and right sides from the base 1 is a bracket for attaching this pressure sensor to an attachment target object.

  On the other hand, the cover 3 is provided with a fitting groove 23 on the outer peripheral edge corresponding to the fitting convex portion 15 described above. Similarly to the fitting convex portion 15, the fitting groove 23 also excludes the insertion opening 25 corresponding to the connector insertion opening 19 shown in FIG. 2A, as shown in FIG. 2B. It is formed at the periphery.

  The base 1 and the cover 3 are coupled by inserting and fitting the above-described fitting convex portion 15 of the base 1 into the fitting groove 23 of the cover 3. At that time, the protrusion 21 provided integrally with the front end surface of the fitting convex portion 15 is in a state where part or all of the front end is plastically deformed and crushed as shown in FIG. S is constructed.

  In addition, the insertion opening portions 19 and 25 shown in FIG. 2 form the above-described connector insertion space 27 (not shown) when the base 1 and the cover 3 shown in FIG. Partitions 28 and 29 are formed in the base 1 and the cover 3, respectively, on the side end. Among these, the insertion recess 28 a for inserting and arranging the terminal 17 drawn from the sensor module 7 is formed in the partition wall 28 on the base 1 side.

  The partition walls 28 and 29 are formed over the entire circumference so as to surround the sensor module 7 as shown in FIG. Among these, the upper and left and right side portions of the partition wall 29 on the cover 3 side in FIG. 2B form the fitting groove 23 with the outer peripheral wall 31 located outside thereof. The outer peripheral wall 31 is formed so as to rise from the outer peripheral edge of the bottom wall 32 of the cover 3.

  In the sensor module 7, protrusions 33 and 35 that protrude from the bottom wall 13 of the base 1 are formed on the terminal plates 37 a and 37 b of the terminal portion 37 that protrudes upward and downward in FIG. 2A of the sensor module 7. Insert into the caulking hole and fix by caulking.

  FIG. 5 shows the internal structure of the sensor module 7. In the sensor device shown in FIG. 5, the structures of the base 1 and the cover 3 are slightly different from those shown in FIG. The major difference is that the base 1 is provided with the fitting projection 15 as in FIG. 1, but the cover 3 is not provided with the fitting groove 23 of FIG. That is, in this configuration, the base 1 and the cover 3 are fitted and fixed by fitting the fitting convex portion 15 into the outer peripheral wall 31 and fitting.

  Further, since the fitting groove 23 of FIG. 1 is not provided, the partition wall 29 is formed only in a portion corresponding to the insertion space 27 of the connector, and the insertion recess 29a in which the terminal 17 is inserted and disposed in the partition wall 29. Is forming.

  Also in the example of FIG. 5, a plastically deformable protrusion 21 similar to that of FIG. 3 is integrally formed on the front end surface of the fitting convex portion 15 formed on the base 1, and the base 1 and the cover 3 are coupled. At this time, a part or all of the tip of the protrusion 21 is plastically deformed and crushed.

  As shown in FIG. 5, the sensor module 7 stores a pressure sensor chip 41 and an integrated circuit chip 43 as sensor chips sealed in a box-shaped package 45 with a sealing material 47. A cover 49 is provided at the left opening of the package 45 in FIG.

  The pressure sensor chip 41 includes a diaphragm formed into a thin film by processing a semiconductor substrate (silicon substrate), and a plurality of piezoresistive elements constituting a bridge circuit on the diaphragm. The piezoresistive element, the integrated circuit chip 43 and the terminal portion 37 are electrically connected by bonding wires 51, respectively.

  The package 45 is made of a resin and includes a main body portion 53 having a concave portion 53 a in which the sealing material 47 is enclosed, and the terminal portion 37 is integrally formed along the bottom portion of the concave portion 53 a of the main body portion 53. A cylindrical oil introduction portion 55 is formed on the opposite side of the main body portion 53 from the recess portion 53a. The oil introduction portion 55 is inserted into a recess 57 formed in the recess portion 13a of the base 1. ing. An O-ring 59 is interposed between the outer peripheral portion of the oil introduction portion 55 and the recess 57. The O-ring 59 is restricted from moving toward the package 45 by a washer 61 provided on the recess 13a side.

  The pressure sensor chip 41 is located at a position corresponding to the oil introduction portion 55 of the package 45, and the oil introduction passage 63 extends from the pressure sensor chip 41 side to the tip surface opposite to the pressure sensor chip 41 in the oil introduction portion 55. Is forming. An end of the oil introduction passage 63 on the pressure sensor chip 41 side communicates with an oil introduction recess 41 a provided in the pressure sensor chip 41.

  Oil 65 for transmitting the pressure from the fluid to the pressure sensor chip 41 is filled in the oil introduction passage 63 and the oil introduction recess 41a. The oil 65 is non-corrosive, and even if the fluid is corrosive, the oil 65 is interposed between the fluid and the pressure sensor chip 41, thereby suppressing the corrosion of the pressure sensor chip 41. be able to.

  On the other hand, the base 1 includes a port portion 67 that protrudes toward the opposite side of the cover 3 at a position corresponding to the oil introduction portion 55, and a through hole 67 a that communicates with the oil introduction passage 63 is provided in the port portion 67. Forming.

  When a fluid such as water flows into the through hole 67a from the opening 67b at the tip of the port 67, the diaphragm of the pressure sensor chip 41 is bent through the oil 65, and the piezoresistive element is distorted. Then, the resistance value of the piezoresistive element changes due to the distortion of the piezoresistive element, and the pressure of the fluid is measured by taking out the detected value detected in accordance with the change.

  In the sensor device configured as described above, the base 1 and the cover 3 accommodating and fixing the sensor module 7 are fitted and fixed by abutting the openings 9 and 11 facing each other. At this time, in the structure of FIG. 1, the fitting convex portion 15 enters the fitting groove 23 and fits, and in the structure of FIG. 5, the fitting convex portion 15 enters inside the outer peripheral wall 31 of the cover 3 and fits. Match. At this time, as shown in FIG. 4 corresponding to FIG. 1, the protrusion 21 provided on the front end surface of the fitting convex portion 15 comes into contact with the bottom surface (bottom wall 32) of the fitting groove 23 of the mating cover 3. As a result, it is plastically deformed and part or all of it is crushed to form the seal portion S.

  In this case, by abutting the base 1 and the cover 3, the resin protrusion 21 is easily plastically deformed to become the seal portion S. Therefore, by simply abutting the cases (base 1 and cover 3), Both can be coupled and fixed while improving the sealing performance between the base 1 and the cover 3.

  Accordingly, in the example of FIG. 5, with the sensor device attached in a vertical relationship as shown in FIG. 6, for example, water W that has entered from the gap between the base 1 and the cover 3 is made plastic, and the protrusion 21 is made plastic. It is blocked by the deformed seal portion S, and the intrusion of water W into the inside can be suppressed.

  When there is no seal portion S in which the protrusion 21 is plastically deformed, the fitting convex portion 15 of the base 1 and the cover 3 are in contact with each other, but their mutually facing surfaces are continuous over the entire surface or in the outer circumferential direction. In this case, it is difficult to avoid the intrusion of water because it is not in contact and a gap is partially formed.

  On the other hand, in the present embodiment, the fitting portion between the base 1 and the cover 3 includes the seal portion S in which the protrusion 21 is continuously crushed in the outer peripheral direction. Intrusion can be suppressed more reliably.

  Moreover, in this embodiment, since the protrusion 21 protrudes toward the protrusion direction on the front end surface in the protrusion direction of the fitting protrusion 15 corresponding to the abutting direction of the base 1 and the cover 3, the protrusion direction Thus, the protrusion 21 is plastically deformed and crushed, and the plastic deformation portion of the protrusion 21 constituting the seal portion S becomes difficult to disperse, so that the sealing performance is further improved.

  Further, in the present embodiment, the protrusion 21 has a tapered shape and has a triangular section with a sharp tip, and therefore, when the base 1 and the cover 3 are brought into contact with each other, the protrusion 21 is formed by the tapered portion on the tip side in the abutting direction. The plastic deformation becomes easy. As a result, the degree of adhesion of the projection 21 to the wall surface of the plastically deformed portion is increased, and the sealing performance is further improved.

  As a modification of the first embodiment, two projections 21 may be provided side by side as shown in FIGS. 7 and 8 corresponding to FIGS. 3 and 4 described above. That is, by providing two protrusions 21, a double seal portion S can be formed, and the sealing performance can be further improved.

  In the first embodiment described above, the protrusion 21 is provided on the front end surface of the fitting convex portion 15, but may be provided on the cover 23 side at a position facing the front end surface. Further, the protrusions 21 may be provided on both the front end surface of the fitting convex portion 15 and the cover 23 side at a position facing the front end surface. In this case, the fitting convex portion 15 and the cover 23 are provided. It is desirable to arrange the protrusions 21 alternately on the side along the outer peripheral direction of the fitting portion.

[Second Embodiment]
In the second embodiment, as shown in FIG. 9A corresponding to an enlarged cross-sectional view of a portion B in FIG. 5, the outer side of the fitting convex portion 15 in the base 1 (upper portion in FIG. 9A). A protrusion 21 </ b> A that protrudes toward the outer peripheral wall 31 is provided on the side surface of the base 1, that is, the side surface that faces the inner surface of the outer peripheral wall 31 of the cover 3. This protrusion 21A is provided over the entire length of the fitting convex portion 15 in the same manner as the protrusion 21 of the first embodiment.

  Further, the protrusion 21A is such that when the base 1 and the cover 3 are brought into contact with each other as shown in FIG. The inclined surface 21Aa is inclined so as to be in front of the contact direction, and the surface opposite to the inclined surface 21Aa is a vertical surface 21Ab substantially perpendicular to the contact direction.

  Thereby, when the front-end | tip of the outer peripheral wall 31 of the other party cover 3 contact | abuts to the inclined surface 21Aa of the processus | protrusion 21A, the processus | protrusion 21A becomes easy to carry out plastic deformation, and a fitting operation | work also becomes easy. Since the protrusion 21A is easily plastically deformed, the degree of adhesion of the plastically deformed portion of the protrusion 21A to the wall surface is increased, and the sealing performance is further improved.

  Further, in this case, the seal portion SA formed by crushing the protrusion 21A is more likely to enter the water W shown in FIG. 6 than the seal portion S formed at the tip of the fitting convex portion 15 in the first embodiment. Located upstream of the route. For this reason, the penetration of the water W into the housing 5 can be suppressed more effectively.

  In the second embodiment described above, the protrusion 21A is provided on the fitting convex portion 15. However, as shown by a two-dot chain line in FIG. 9B, the fitting convex portion of the outer peripheral wall 31 in the cover 3 is provided. 15 may be provided on a surface facing the surface 15, or may be provided on both surfaces of the fitting convex portion 15 and the outer peripheral wall 31 facing each other. Further, in the example of FIG. 1, the protrusion 21 </ b> A is not only between the fitting convex portion 15 and the outer peripheral wall 31, but also at least one of the opposing surfaces of the fitting convex portion 15 and the inner partition wall 29. May be provided.

  In addition, although the protrusion 21 and protrusion 21A in each above-mentioned embodiment are consciously produced with a shaping | molding die by integrally forming with the other part of the base 1 or the cover 3, the part which provides these protrusion 21 and protrusion 21A By setting as the parting line of the mold at the time of molding, the burr of the product formed along the parting line can be used as a protrusion.

1 Base (first case)
3 Cover (second case)
DESCRIPTION OF SYMBOLS 5 Housing 9 Base opening 11 Cover opening 13 Base bottom wall 15 Base fitting convex part (outer peripheral wall)
21, 21A Protrusion 21Aa Inclined surface of protrusion 21Ab Vertical surface of protrusion 31 Outer peripheral wall of cover 32 Bottom wall of cover 41 Pressure sensor chip (sensor chip)
S, SA seal part

Claims (5)

  Housings for housing sensor chips that detect fluid pressure include first and second cases made of resin that are fitted with the openings facing each other, and the first and second cases. When the first and second cases are abutted and fitted to at least one of the above, a protrusion serving as a seal portion is provided by being relatively pressed and plastically deformed between the other and the other case. A sensor device.   2. The sensor device according to claim 1, wherein the protrusion protrudes toward a front end surface of the first and second cases in the abutting direction with respect to the abutting direction.   The sensor device according to claim 2, wherein the protrusion has a tapered shape.   Each of the first and second cases includes a bottom wall and an outer peripheral wall rising from an outer peripheral edge of the bottom wall, and either one of the first and second cases is an outer peripheral wall of the other outer wall. 2. The sensor device according to claim 1, wherein the protrusion is provided on an opposite surface of at least one of the one outer peripheral wall and the other outer peripheral wall.   In the protrusion, the surface facing the abutting direction of the other case that abuts against the case on the side where the projection is provided is an inclined surface that inclines so that the tip side is more forward in the abutting direction. The sensor device according to claim 4, wherein the side surface is a vertical surface perpendicular to the abutting direction.

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