JP6314766B2 - Physical quantity sensor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a physical quantity sensor in which a sensor unit and a terminal are electrically connected via a metal rod and a method for manufacturing the same.

  Conventionally, as this kind of physical quantity sensor, a pressure sensor for measuring pressure has been proposed (for example, see Patent Document 1). Specifically, in this pressure sensor, a lead wire is connected between the sensor unit and the wiring board connected to the terminal, and the lead wire is arranged linearly between the terminal and the wiring board. ing. That is, the lead wire is arranged in a fully extended state. In addition, the lead wire, the sensor part, and the wiring board are joined via a connection member such as solder.

JP 2007-139453 A

  However, in the pressure sensor as described above, stress may be generated in the connection member between the lead wire, the sensor unit, and the wiring board due to material creep or the like, and a crack or the like may occur in the connection member. And when the said crack generate | occur | produces, a conduction | electrical_connection defect may generate | occur | produce between a lead wire, a sensor part, and a wiring board.

  In the above description, the pressure sensor has been described as an example. However, such a problem also occurs in a physical quantity sensor such as an acceleration sensor or an angular velocity sensor.

  An object of this invention is to provide the physical quantity sensor which can suppress that a conduction defect generate | occur | produces in view of the said point, and its manufacturing method.

In order to achieve the above object, according to the first aspect of the present invention, a sensor unit (50) that outputs a sensor signal corresponding to a physical quantity, a terminal (111) electrically connected to the sensor unit, a sensor unit, A rod (80) disposed between the terminal and electrically connecting the sensor part and the terminal, and having a bottomed cylindrical shape having an opening (20a) and a hollow part (20b), The first metal case (20), which is a diaphragm portion (20c), has a bottomed cylindrical shape having an opening (30a) and a hollow portion (30b), and the bottom portion is a diaphragm portion (30c). A sensor part is disposed in the hollow part, and a second metal case (disposed in the hollow part of the first metal case so that a load applied to the first metal case is transmitted to the diaphragm part ( 0), a connector having a terminal (111) and a load transmission member (40) disposed between the diaphragm portion and the sensor portion of the second metal case and transmitting the load applied to the diaphragm portion to the sensor portion A member (100), and a housing (10) having a hollow portion (10c), one end of which is joined to the first metal case, and the other end is assembled to the connector member; rod is made of a metal material having a one end and the other section, the deflected flexure with respect to the virtual straight line connecting the sensor unit and the terminal (L) have a (81), disposed in the hollow portion of the housing It is characterized by having a bent part in the hollow part .

  According to this, when a stress is generated in the connecting portion between the rod, the sensor portion, and the terminal, the stress can be relieved by the displacement of the bending portion. For this reason, it can suppress that stress concentration generate | occur | produces in each connection part, and can suppress that a conduction | electrical_connection defect generate | occur | produces between a rod, a sensor part, and a terminal.

According to a third aspect of the present invention, there is provided a first connection step for connecting the terminal and the other end of the rod, a second connection step for connecting the sensor portion and one end of the rod, and a bending portion on the rod. forming, after the step of preparing a connector member (100) having a terminal, a step of preparing a housing (10) cylindrical having a hollow portion (10c), a row physician first connecting step The step of assembling the connector member to the other end of the housing is performed so that the one end of the rod protrudes from the one end of the housing, and the second connection step projects the other end of the rod from the one end of the housing. And a step of preparing a first metal case (20) having a bottomed cylindrical shape having an opening (20a) and a hollow portion (20b), the bottom portion being a diaphragm portion (20c). Open Preparing a second metal case (30) having a bottomed cylindrical shape having a portion (30a) and a hollow portion (30b), the bottom portion being a diaphragm portion (30c), and a second connecting step The step of housing the sensor portion in the hollow portion of the second metal case and the step of housing the second metal case in the hollow portion of the first metal case and forming the bent portion The opening of the case is brought close to one end of the housing and the rod is bent in the hollow portion of the housing to perform a step of joining the first metal case and one end of the housing .

  According to this, when a stress is generated in the connecting portion between the rod, the sensor portion, and the terminal, a physical quantity sensor having a bending portion that relaxes the stress can be manufactured.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is sectional drawing of the pressure sensor in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing process of the pressure sensor shown in FIG. FIG. 3 is a cross-sectional view showing the manufacturing process of the pressure sensor following FIG. 2.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example in which the physical quantity sensor of the present invention is applied to a pressure sensor will be described. The pressure sensor of the present embodiment is preferably attached to, for example, an automobile engine as a member to be attached and used to detect the pressure in the combustion chamber of the engine.

  As shown in FIG. 1, the pressure sensor includes a cylindrical housing 10 having a hollow portion 10 c having openings 10 a and 10 b at both ends. The housing 10 of the present embodiment includes a cylindrical main body 11 and an elongated cylinder having an inner diameter and an outer diameter shorter than the main body 11 and a screw portion 13 that can be screwed to an attached member on an outer peripheral wall surface. And a pipe-shaped portion 12. Such a housing 10 is configured by integrally molding a metal such as SUS630 by cutting or cold forging.

  Further, the tip of the pipe portion 12 (the opening 10a side of the housing 10) has a tapered shape whose diameter decreases toward the tip, and the measurement medium when the screw portion 13 is screwed to the attached member. A pressure seal portion 14 is formed for sealing. The first end of the pipe portion 12 having a bottomed cylindrical shape having an opening 20a and a hollow portion 20b at the end on the tip side of the pressure seal portion 14 is a thin-walled diaphragm portion 20c. A metal case 20 is provided. The first metal case 20 has a transmission portion 20d that protrudes toward the opening 20a at a substantially central portion of the bottom, and an intermediate portion between the opening 20a and the diaphragm portion 20c is connected to the tip of the pipe portion 12. It is joined by laser welding or the like.

  The first metal case 20 is provided with a second metal case 30 having a bottomed cylindrical shape having an opening 30a and a hollow portion 30b, and having a thin bottom diaphragm portion 30c. Specifically, the second metal case 30 is accommodated in the first metal case 20 so that the diaphragm portion 30c of the second metal case 30 contacts the transmission portion 20d of the first metal case 20. The first and second metal cases 20 and 30 are formed by integrally molding a metal such as SUS630 by cutting or cold forging.

  And in the hollow part 30b of the 2nd metal case 30, the load transmission member 40, the sensor part 50, the insulation member 60, and the preload application member 70 are arrange | positioned in an order from the diaphragm part 30c side.

  The load transmission member 40 has a tapered shape, and is a cone having a substantially trapezoidal cross section along the axial direction. And it arrange | positions so that one surface of the front end side may contact | abut with the diaphragm part 30c. Such a load transmission member 40 is configured by cutting or cold forging a metal such as SUS630.

  The sensor unit 50 includes a sensing unit 51 that outputs a sensor signal according to pressure, and an electrode 52 that is electrically connected to the sensing unit 51. The sensing unit 51 is disposed on the load transmission member 40 side. ing. In the present embodiment, the sensing unit 51 is composed of a disk-shaped piezoelectric element made of a piezoelectric material such as quartz, and outputs a sensor signal (charge) corresponding to pressure. The electrode 52 has a disk shape made of a metal such as SUS630.

  And the sensor part 50 (electrode 52) is comprised with metals, such as copper, and is electrically connected with the one end part of the rod 80 for electrically connecting the sensor part 50 and the 1st terminal 111 mentioned later. Yes. In the present embodiment, the rod 80 is made of a metal material such as Ni having one end and the other end, and the sensor unit 50 and the rod 80 are joined by resistance welding.

  The insulating member 60 insulates the sensor unit 50 from the preload applying member 70 and is made of alumina or the like, and has an annular shape in which a through hole 60a is formed. The rod 80 is drawn out from the through hole 60a.

  The preload application member 70 has a cylindrical shape with both ends having hollow portions 70a as openings, and is made of a metal such as SUS630. The end of the preload application member 70 opposite to the insulating member 60 protrudes from the second metal case 30, and a predetermined preload is applied to the load transmission member 40, the sensor unit 50, and the insulating member 60. As described above, the end opposite to the insulating member 60 is joined to the first metal case 20 by laser welding or the like. Further, the rod 80 is drawn into the hollow portion 10 c of the housing 10 through the hollow portion 70 a of the preload applying member 70.

  A cylindrical insulating tube made of polyimide or the like is disposed along the side surface of the inner wall in the second metal case 30, and the second metal case 30, the load transmission member 40, and the sensor unit 50 are arranged. Insulation can be achieved. Similarly, the preload applying member 70 is provided with a cylindrical insulating tube made of polyimide or the like along the side surface of the inner wall, so that the preload applying member 70 and the rod 80 can be insulated. ing.

  In addition, the opening 10 b in the housing 10 is provided with a substantially cylindrical connector member 100 made of resin such as PPS (polyphenylene sulfide) through an O-ring 90.

  The connector member 100 has a recess 101 formed at one end (the end on the lower side in FIG. 1) and a recess 102 formed at the other end (the end on the upper side in FIG. 1). A depression 103 is formed in the part. The connector member 100 is integrated with the housing 10 by inserting one end portion side into the hollow portion 10c from the opening portion 10b of the housing 10 and caulking the opening end portion 15 on the opening portion 10b side of the housing 10. Yes.

  Further, the connector member 100 is provided with first and second terminals 111 and 112 formed integrally with the connector member 100 by insert molding. Specifically, the first terminal 111 is provided in the connector member 100 such that one end portion projects into the recess 101 and the other end portion projects into the recess 103. Further, the second terminal 112 is provided such that one end projects into the recess 102 and the other end projects into the recess 103.

  Further, the wiring board 120 is mounted on the connector member 100 via an adhesive (not shown) in the recess 103. The wiring substrate 120 has a wiring pattern (not shown) formed on the front and back surfaces, and the wiring patterns formed on the front and back surfaces are appropriately connected via electrodes embedded in the through holes. A plurality of electronic components 121 for amplifying sensor signals are mounted on the front and back surfaces of the wiring board 120. In the present embodiment, an accommodation recess 103 a is formed on the bottom surface of the recess 103, and the electronic component 121 mounted on the back surface of the wiring board 120 facing the bottom surface of the recess 103 is an accommodation recess 103 a. Is to be housed.

  The wiring board 120 is electrically connected to the other ends of the first and second terminals 111 and 112 exposed in the recess 103 via bonding wires 131 and 132.

  In addition, the first terminal 111 has a T-shaped cross section having a joint portion 111a that is widened in a normal direction to a straight line connecting the one end portion and the other end portion at one end portion. One end of the first terminal 111 is electrically connected to the other end of the rod 80. In the present embodiment, the rod 80 and the first terminal 111 are joined by resistance welding. Note that one end of the second terminal 112 is electrically connected to an external circuit (not shown) via a wire harness or the like.

  The rod 80 has a bent portion 81 that is bent with respect to an imaginary straight line L that connects the sensor portion 50 and the first terminal 111 in the hollow portion 10 c of the housing 10. In other words, the rod 80 has a bent portion with respect to the virtual straight line L and is not arranged in a straight line.

  The above is the configuration of the pressure sensor in the present embodiment. Such a pressure sensor is attached to a vehicle engine as a member to be attached by screwing the screw portion 13 and is used to detect the pressure in the combustion chamber of the engine. When pressure is applied to the diaphragm portion 20c (first metal case 20), the diaphragm portion 20c is transferred to the sensor portion 50 via the transmission portion 20d, the diaphragm portion 30c (second metal case 30), and the load transmission member 40. The generated load is transmitted. For this reason, polarization occurs in the sensing unit 51 made of a piezoelectric material, and a sensor signal (charge) corresponding to the pressure is transmitted to the wiring board 120 via the electrode 52 and the rod 80 to detect the pressure. .

  Next, a method for manufacturing the pressure sensor will be described with reference to FIG.

  First, as shown in FIG. 2A, the connector member 100 in which the first and second terminals 111 and 112 are insert-molded is prepared, and the electronic component 121 is mounted in the recess 103 of the connector member 100. A substrate 120 is placed. Then, the wiring board 120 and the other end portions of the first and second terminals 111 and 112 are electrically connected via bonding wires 131 and 132.

  Next, as shown in FIG. 2B, the other end of the rod 80 is joined to one end of the first terminal 111 by welding.

  Subsequently, as shown in FIG. 2C, the connector member 100 is inserted into the housing 10 by inserting one end of the connector member 100 into the hollow portion 10 c of the housing 10 and caulking the open end 15 of the housing 10. Assemble. At this time, one end of the rod 80 protrudes from the opening 10a of the housing 10 and is linear.

  Next, as shown in FIG. 3A, the sensor unit 50 (electrode 52) and one end of the rod 80 are electrically connected. And after arrange | positioning the load transmission member 40, the sensor part 50, the insulating member 60, and the preload application member 70 in the 2nd metal case 30, this is arrange | positioned in the 1st metal case 20. FIG.

  Subsequently, as shown in FIG. 3B, in the hollow portion 10c of the housing 10, the first metal case 20 is brought close to the housing 10 so that the bending portion 81 is formed on the rod 80. 20 and the housing 10 are joined by welding joining. By performing the above steps, the pressure sensor is manufactured.

  When performing the process of FIG. 2B, a temporary bending part or the like may be formed in advance so that the bending part 81 is easily formed in the process of FIG.

  As described above, in this embodiment, the bending portion 81 is formed on the rod 80. For this reason, when a stress is generated in the connecting portion between the rod 80 and the sensor unit 50 and the first terminal 111 due to material creep or the like, the stress can be relieved by the displacement of the bending portion 81. For this reason, it can suppress that stress concentration generate | occur | produces in a connection part, and can suppress that the electrical conduction defect generate | occur | produces between the rod 80, the sensor part 50, and the 1st terminal 111. FIG.

  Further, even when a stress is generated in the connecting portion between the rod 80, the sensor unit 50, and the first terminal 111 due to the use of the pressure sensor in a vibration environment, the bending portion 81 is displaced to relieve the stress. It is possible to suppress the occurrence of poor conduction.

  Further, the rod 80 is joined to the sensor unit 50 and the first terminal 111 by resistance welding, and is integrated with the sensor unit 50 and the first terminal 111. For this reason, if the connecting portion is broken, the base material is broken, and therefore, the fracture life can be derived with high accuracy by the material constituting the rod 80 and the shape of the bent portion 81.

  Note that a conductive spring member is disposed between the sensor unit 50 and the rod 80, and the sensor unit 50 and the rod 80 are electrically connected by the spring member, and between the sensor unit 50 and the rod 80. It is also conceivable to relieve the stress generated in the film. However, such a structure requires a manufacturing process such as load management by a spring contact and makes the structure complicated. On the other hand, in the pressure sensor of this embodiment, since it is only necessary to form the bending portion 81 in the rod 80, the manufacturing process is not complicated, and the rod 80, the sensor portion 50, and the first terminal 111 can be connected. Occurrence of poor conduction can be suppressed.

(Other embodiments)
The present invention is not limited to the embodiment described above, and can be appropriately changed within the scope described in the claims.

  For example, in the first embodiment, the example in which the rod 80, the sensor unit 50, and the first terminal 111 are resistance-welded has been described. However, the rod 80, the sensor unit 50, and the first terminal 111 are laser-welded. Etc. may be joined. Moreover, the rod 80, the sensor part 50, and the 1st terminal 111 may be electrically connected through the solder.

  In the first embodiment, the pressure sensor has been described as the physical quantity sensor of the present invention. However, the physical quantity sensor of the present invention can be applied to other sensors such as an acceleration sensor and an angular velocity sensor.

DESCRIPTION OF SYMBOLS 10 Housing 50 Sensor part 80 Rod 81 Deflection part 100 Connector member 111 Terminal

Claims (3)

A sensor unit (50) for outputting a sensor signal corresponding to a physical quantity;
A terminal (111) electrically connected to the sensor unit;
A rod (80) disposed between the sensor part and the terminal and electrically connecting the sensor part and the terminal;
A first metal case (20) having a bottomed cylindrical shape having an opening (20a) and a hollow portion (20b), the bottom being a diaphragm portion (20c);
The bottomed cylindrical shape has an opening (30a) and a hollow part (30b), the bottom part is a diaphragm part (30c), and the sensor part is disposed in the hollow part, and the diaphragm part has the A second metal case (30) disposed in a hollow portion of the first metal case so that a load applied to the first metal case is transmitted;
A load transmitting member (40) disposed between the diaphragm portion of the second metal case and the sensor portion, and transmitting a load applied to the diaphragm portion to the sensor portion;
A connector member (100) having the terminal (111);
A cylindrical shape having a hollow portion (10c), one end side is joined to the first metal case, and the other end side is assembled to the connector member; and a housing (10),
The rod is made of a metal material having a one end and the other end portion, connecting said said sensor unit terminals have a deflected flexure with respect to the imaginary straight line (L) (81), of the housing A physical quantity sensor which is disposed in a hollow portion and has the bending portion in the hollow portion .   2. The physical quantity sensor according to claim 1, wherein one end of the rod is welded to the sensor unit and the other end is welded to the terminal. A sensor unit (50) for outputting a sensor signal corresponding to a physical quantity;
A terminal (111) electrically connected to the sensor unit;
A rod (80) disposed between the sensor part and the terminal and electrically connecting the sensor part and the terminal;
The rod is made of a metal material having one end and the other end, and a method of manufacturing a physical quantity sensor having a bent portion (81) bent with respect to an imaginary straight line (L) connecting the sensor portion and the terminal. In
A first connection step of connecting the terminal and the other end of the rod;
A second connection step of connecting the sensor unit and one end of the rod;
Forming the bent portion on the rod;
Preparing a connector member (100) having the terminal;
Line physicians and step, providing a cylindrical housing having a hollow portion (10c) (10)
After performing the first connection step, performing a step of assembling the connector member to the other end of the housing such that one end of the rod protrudes from the one end of the housing,
The second connection step is performed with the other end of the rod protruding from one end of the housing,
Further, a step of preparing a first metal case (20) having a bottomed cylindrical shape having an opening (20a) and a hollow portion (20b), and having a bottom portion as a diaphragm portion (20c),
A step of preparing a second metal case (30) having a bottomed cylindrical shape having an opening (30a) and a hollow portion (30b), and the bottom portion being a diaphragm portion (30c),
After performing the second connection step, the sensor unit is accommodated in the hollow portion of the second metal case, and the second metal case is accommodated in the hollow portion of the first metal case,
The step of forming the bent portion is performed by bringing the opening of the first metal case closer to one end of the housing and bending the rod in the hollow portion of the housing,
A method of manufacturing a physical quantity sensor, comprising performing a step of joining the first metal case and one end of the housing .

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