WO2022209268A1

WO2022209268A1 - Physical quantity measurement device

Info

Publication number: WO2022209268A1
Application number: PCT/JP2022/004127
Authority: WO
Inventors: 典男石塚; 暁上ノ段; 望八文字; 瑞紀伊集院; 孝之余語
Original assignee: 日立Astemo株式会社
Priority date: 2021-04-02
Filing date: 2022-02-02
Publication date: 2022-10-06
Also published as: CN116997774A; JP2022158414A; JP7575988B2

Abstract

This invention reduces thermal stress near an interface with a housing sealing member and ensures wire connection reliability in a simple manner. A physical quantity measurement device 20 comprises a housing 100, a connector terminal 117 sealed in the housing 100, a wire 350 bonded to the connector terminal 117, and a sealing member 250 that seals the wire 350 and is in contact with the connector terminal 117 and housing 100. The linear expansion coefficient of the housing 100 is greater than that of the sealing member 250. The connector terminal 117 comprises a bonding surface 118 and a lateral surface 119 that is continuous with the bonding surface 118 and is sealed by the housing 100. The housing 100 comprises a first surface 115 that is in contact with the lateral surface 119 and a second surface 116 that is continuous with the first surface 115 and is in contact with the sealing member 250. The end part 116a of the second surface 116 that is continuous with the first surface 115 is formed into a shape that is flush with the bonding surface 118.

Description

Physical quantity measuring device

The present invention relates to a physical quantity measuring device.

Physical quantities such as air flow rate, pressure, temperature or humidity are widely used as important control parameters in various devices. A physical quantity measuring device that measures these physical quantities is one of the important components that affect the performance of the equipment. For example, in vehicles equipped with an internal combustion engine, there is an extremely high demand for fuel efficiency and exhaust gas purification. To meet these demands, there is a need for a physical quantity measuring device that can measure the intake air amount, which is the main control parameter of an internal combustion engine, with high accuracy.

A physical quantity measuring device such as the one described above is disclosed in Patent Document 1, for example. The device of Patent Document 1 has a structure in which a circuit board is adhered to a housing, and a sensor for measuring the amount of intake air is mounted on the circuit board. A circuit board on which electronic components such as a sensor are mounted and a connector terminal for providing an electric signal from the circuit board to an external device are sometimes connected by wire bonding. A method of connecting a circuit board and a connector terminal by wire bonding is disclosed in, for example, Japanese Unexamined Patent Application Publication No. 2002-200021. In the device disclosed in Patent Literature 2, a connector terminal integrally formed with a housing and a circuit board accommodated in the housing are connected by wire bonding.

WO2015/117971 JP 2004-28934 A

In the physical quantity measuring device, after the connector terminals integrally molded with the housing and the circuit board housed in the housing are connected by wire bonding, the connector terminals and wires are sometimes sealed with a resin sealing member. At this time, if the linear expansion coefficient of the housing is larger than that of the sealing member, a large thermal stress is generated in the housing near the interface with the sealing member. As a result, there is a possibility that the connector terminal sealed in the housing and the sealing member will separate and the wire sealed in the sealing member will break due to thermal fatigue. It is also conceivable to select a resin material for the housing so that the difference in coefficient of linear expansion between the housing and the sealing member is small. However, a resin material that is selected to minimize the difference in linear expansion coefficient between the two while satisfying the performance required for a physical quantity measuring device that is used in a harsh environment is expensive, and that resin material is used for the housing. It is not easy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides a physical quantity measuring device capable of easily ensuring wire connection reliability by suppressing thermal stress generated near the interface between a housing and a sealing member. intended to provide

In order to solve the above-described problems, the physical quantity measuring apparatus of the present invention includes: a housing containing a sensor for measuring a physical quantity; terminals sealed in the housing; wires bonded to the terminals; a sealing member contacting each of the terminals and the housing, wherein the linear expansion coefficient of the housing is larger than that of the sealing member, and the terminals are bonded to the wires. and a bonding surface in contact with the sealing member; and a side surface continuous with the bonding surface and sealed in the housing, the housing comprising: a first surface in contact with the side surface of the terminal; a second surface continuous with the first surface and in contact with the sealing member, wherein an end of the second surface continuous with the first surface is formed flush with the bonding surface. It is characterized by

According to the present invention, it is possible to provide a physical quantity measuring device that can easily ensure wire connection reliability by suppressing thermal stress generated near the interface between the housing and the sealing member. Problems, configurations and effects other than the above will be clarified by the following description of the embodiment.

1 is a diagram showing the configuration of an electronic fuel injection type internal combustion engine control system in which the physical quantity measuring device of the present embodiment is used; FIG. 1 is a front view of a physical quantity measuring device of this embodiment; FIG. FIG. 3 is a rear view of the physical quantity measuring device shown in FIG. 2; FIG. 3 is a front view of the physical quantity measuring device with the cover shown in FIG. 2 removed; FIG. 4 is a rear view of the physical quantity measuring device from which the sealing member shown in FIG. 3 is removed; 6 is an enlarged view of the vicinity of the connector terminal shown in FIG. 5; FIG. FIG. 7 is a schematic diagram of a cross section taken along the line AA shown in FIG. 6; FIG. 8 is an enlarged view of a portion surrounded by a dashed line shown in FIG. 7; The figure explaining the physical-quantity measuring device of a comparative example. FIG. 10 is an enlarged view of a portion surrounded by a dashed line shown in FIG. 9; The figure explaining the physical-quantity measuring device of the modification of this embodiment. FIG. 12 is an enlarged view of a portion surrounded by a dashed line shown in FIG. 11;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that components denoted by the same reference numerals in each embodiment have the same functions in each embodiment unless otherwise specified, and thus descriptions thereof will be omitted.

FIG. 1 is a diagram showing the configuration of an electronic fuel injection type internal combustion engine control system 1 in which the physical quantity measuring device 20 of the present embodiment is used.

In the internal combustion engine control system 1, based on the operation of the internal combustion engine 10 having the engine cylinder 11 and the engine piston 12, the gas to be measured 2, which is the intake air, is drawn from the air cleaner 21 and passes through the main passage 22, such as the intake body. It is led to the combustion chamber of the engine cylinder 11 via the throttle body 23 and the intake manifold 24 . The physical quantity of the measured gas 2, which is the intake air introduced into the combustion chamber, is measured by the physical quantity measuring device 20 of the present embodiment, fuel is supplied from the fuel injection valve 14 based on the measured physical quantity, and the measured gas 2 together with the air-fuel mixture is led to the combustion chamber. In this embodiment, the fuel injection valve 14 is provided in the intake port of the internal combustion engine, and the fuel injected into the intake port forms an air-fuel mixture together with the gas 2 to be measured. It burns and produces mechanical energy.

The fuel and air led to the combustion chamber are in a mixed state of fuel and air, and are explosively combusted by the spark ignition of the spark plug 13 to generate mechanical energy. The gas after combustion is led to an exhaust pipe through an exhaust valve 16 and discharged out of the vehicle as exhaust gas 3 from the exhaust pipe. The flow rate of the gas to be measured 2, which is the intake air introduced into the combustion chamber, is controlled by a throttle valve 25 whose opening varies according to the operation of the accelerator pedal. The fuel supply amount is controlled based on the flow rate of the intake air led to the combustion chamber, and the driver controls the opening of the throttle valve 25 to control the flow rate of the intake air led to the combustion chamber. The mechanical energy generated by the engine can be controlled.

Physical quantities such as the flow rate, temperature, humidity or pressure of the gas 2 to be measured, which is the intake air taken in from the air cleaner 21 and flowing through the main passage 22, are measured by the physical quantity measuring device 20. A signal is input to the controller 4 . In addition, the output of a throttle angle sensor 26 that measures the opening of the throttle valve 25 is input to the control device 4, and the positions and states of the engine piston 12, the intake valve 15 and the exhaust valve 16 of the internal combustion engine 10, and further the internal combustion engine 10 The output of the rotation angle sensor 17 is input to the control device 4 in order to measure the rotation speed of . The output of the oxygen sensor 28 is input to the control device 4 in order to measure the state of the mixture ratio between the amount of fuel and the amount of air from the state of the exhaust gas 3 .

The control device 4 calculates the fuel injection amount and ignition timing based on the physical quantity of the intake air, which is the output of the physical quantity measuring device 20, and the rotation speed of the internal combustion engine 10 measured based on the output of the rotation angle sensor 17. . Based on these calculation results, the amount of fuel supplied from the fuel injection valve 14 and the ignition timing of ignition by the spark plug 13 are controlled. The fuel supply amount and ignition timing are actually further based on the temperature measured by the physical quantity measuring device 20, the change state of the throttle angle, the change state of the engine rotation speed, and the air-fuel ratio state measured by the oxygen sensor 28. and fine-grained control. Further, the control device 4 controls the amount of air bypassing the throttle valve 25 by the idle air control valve 27 in the idling state of the internal combustion engine, thereby controlling the rotational speed of the internal combustion engine 10 in the idling state.

The fuel supply amount and ignition timing, which are the main control variables of the internal combustion engine 10, are both calculated using the output of the physical quantity measuring device 20 as a main parameter. Therefore, improving the measurement accuracy of the physical quantity measuring device 20, suppressing changes over time, and improving reliability are important for improving vehicle control accuracy and ensuring reliability.

Especially in recent years, the demand for fuel efficiency of vehicles is very high, and the demand for exhaust gas purification is also very high. In order to meet these demands, it is extremely important to measure the physical quantity of the intake air with high accuracy using the physical quantity measuring device 20 . It is also important that the physical quantity measuring device 20 ensures high reliability.

A vehicle equipped with the physical quantity measuring device 20 is used in an environment with large changes in temperature and humidity. It is preferable that the physical quantity measuring device 20 is designed to deal with changes in temperature and humidity in the environment in which it is used, as well as with respect to dust and contaminants.

Also, the physical quantity measuring device 20 is attached to an intake pipe that is affected by the heat generated by the internal combustion engine 10 . Therefore, the heat generated by the internal combustion engine is transmitted to the physical quantity measuring device 20 through the intake pipe. Since the physical quantity measuring device 20 measures the flow rate of the gas 2 to be measured by conducting heat transfer with the gas 2 to be measured, it is important to suppress the influence of heat from the outside as much as possible.

As described in the following description, the physical quantity measuring device 20 mounted on the vehicle simply solves the problems described in the column of the problems to be solved by the invention, and produces the effects described in the column of the effects of the invention. In addition, by fully considering the various problems described above, various problems required of the product can be solved, and various effects can be obtained. Specific problems to be solved by the physical quantity measuring device 20 and specific effects achieved will be described in the following description.

FIG. 2 is a front view of the physical quantity measuring device 20 of this embodiment. FIG. 2 shows the cover 200 attached to the housing 100 . FIG. 3 is a rear view of the physical quantity measuring device 20 shown in FIG. FIG. 3 shows a state in which the sealing member 250 covers the circuit board 300 . FIG. 4 is a front view of the physical quantity measuring device 20 with the cover 200 shown in FIG. 2 removed. FIG. 5 is a rear view of the physical quantity measuring device 20 with the sealing member 250 shown in FIG. 3 removed. In the following description, it is assumed that the gas 2 to be measured flows along the central axis 22a of the main passage 22 shown in FIG.

The physical quantity measuring device 20 is used while being inserted into the main passage 22 through an attachment hole provided in the passage wall of the main passage 22 and fixed to the main passage 22 . The physical quantity measuring device 20 includes a housing arranged in a main passage 22 through which the gas 2 to be measured flows. The housing of the physical quantity measuring device 20 includes a housing 100, a cover 200 attached to a front surface portion 121 of a measurement unit 113 described later of the housing 100, and a seal that seals a circuit board 300 exposed from a rear surface portion 122 of the measurement unit 113. and a stop member 250 .

The housing 100 is formed, for example, by injection molding a synthetic resin material. The resin material used for molding the housing 100 may be PBT (polybutylene terephthalate) resin, which satisfies the required performance of the physical quantity measuring device 20 and is relatively inexpensive. The cover 200 is made of, for example, a plate-shaped member made of metal material or synthetic resin material. In this embodiment, it is formed by injection molding an aluminum alloy or synthetic resin material. The cover 200 has a size that completely covers the front portion 121 of the measuring portion 113 . The sealing member 250 is formed by, for example, pouring a synthetic resin material into the exposed area of the circuit board 300 in the back surface portion 122 of the measurement unit 113 and molding. The resin material used for molding the sealing member 250 may be epoxy resin or the like that satisfies the required performance of the physical quantity measuring device 20 .

The housing 100 includes a flange 111 for fixing the physical quantity measuring device 20 to the main passage 22, and a connector 112 protruding from the flange 111 and exposed to the outside from the main passage 22 for electrical connection with an external device. have. Furthermore, the housing 100 has a measuring portion 113 extending from the flange 111 toward the central axis 22 a of the main passage 22 to measure the physical quantity of the gas 2 to be measured flowing through the main passage 22 .

The measurement unit 113 is a part of the housing 100 that houses sensors for measuring physical quantities such as flow rate, temperature, humidity or pressure. Specifically, the measurement unit 113 accommodates a chip package 310 having a flow rate detection element 321 , a temperature sensor 331 , a humidity sensor 333 and a pressure sensor 335 . The measurement part 113 has a thin and long shape extending straight from the flange 111 . The measuring portion 113 has a wide front portion 121 and a rear portion 122 , a pair of

narrow side portions

123 and 124 , and a narrow tip surface portion 125 .

The front part 121 and the back part 122 are rectangular surfaces having long sides and short sides corresponding to the longitudinal direction and the lateral direction of the measuring part 113, respectively. It is the surface. The front portion 121 is a portion of the measurement portion 113 in which the

secondary passages

134 and 135 are formed. The rear portion 122 is a portion of the measurement portion 113 on the side opposite to the front portion 121 . The front part 121 and the back part 122 are arranged parallel to each other along the central axis 22a of the main passage 22 when the physical quantity measuring device 20 is attached to the main passage 22 . The side portion 123 is located on one side of the measuring portion 113 in the short direction, and is arranged toward the upstream side of the main passage 22 when the physical quantity measuring device 20 is attached to the main passage 22 . The side portion 124 is positioned on the other side of the measuring portion 113 in the short direction, and is arranged toward the downstream side of the main passage 22 when the physical quantity measuring device 20 is attached to the main passage 22 . The tip surface portion 125 is a surface that is continuous with the front surface portion 121 , the rear surface portion 122 , the side surface portion 123 and the side surface portion 124 . The tip face portion 125 is located on the end face of the measuring portion 113 separated from the flange 111 and arranged in parallel along the central axis 22a of the main passage 22 when the physical quantity measuring device 20 is attached to the main passage 22 . In the physical quantity measuring device 20, the

side portions

123 and 124 facing the upstream side and the downstream side of the main passage 22 have a narrow shape, so that the fluid resistance to the gas 2 to be measured can be suppressed to a small value. can.

In the present embodiment, the posture of the physical quantity measuring device 20 in a state of being attached to the main passage 22 is such that the proximal end portion of the measuring portion 113 that is close to the flange 111 is arranged on the upper side, and the measuring portion 113 that is separated from the flange 111 is positioned at the upper side. This is a posture in which the tip surface portion 125 is arranged on the lower side. However, the posture of the physical quantity measuring device 20 attached to the main passage 22 is not limited to the present embodiment, and various postures can be adopted. For example, the posture of the physical quantity measuring device 20 may be a posture in which the measuring unit 113 is mounted horizontally so that the base end portion and the distal surface portion 125 of the measuring unit 113 are at the same height.

The measurement unit 113 has an inlet 131 of the sub-passages 134 and 135 provided on the side surface 123 , and a first outlet 132 and a second outlet 133 provided on the side surface 124 . The inlet 131 , the first outlet 132 , and the second outlet 133 are provided at positions close to the tip surface portion 125 of the measuring portion 113 in the direction from the flange 111 toward the central axis 22 a of the main passage 22 . The second outlet 133 is arranged toward the downstream side of the main passage 22 . The second outlet 133 has an opening area slightly larger than that of the first outlet 132 , and is provided at a position closer to the base end side of the measuring section 113 than the first outlet 132 . The measurement unit 113 can take into the

sub-passages

134 and 135 the gas 2 to be measured that flows through the portion near the central axis 22 a away from the inner surface of the passage wall of the main passage 22 . Thereby, the physical quantity measuring device 20 can measure the flow rate of the gas 2 to be measured flowing in the portion near the central axis 22a, and can suppress deterioration in measurement accuracy due to the influence of heat or the like.

The measurement unit 113 is provided with

sub-passages

134 and 135 that take in part of the gas 2 to be measured flowing through the main passage 22, and a circuit board 300 on which sensors for measuring physical quantities are mounted.

The sub-passages 134 and 135 are provided in a concave shape in the front part 121 of the measuring part 113 and are covered by attaching a cover 200 to the housing 100 . The circuit board 300 is provided in a region of the measuring section 113 that is close to the side surface section 123 . The

secondary passages

134 and 135 are provided over a region of the measuring section 113 that is closer to the tip surface portion 125 than the circuit board 300 and a region that is closer to the side surface portion 124 than the circuit board 300 . The sub-passages 134 , 135 have a first sub-passage 134 and a second sub-passage 135 .

The first sub-passage 134 extends in the lateral direction of the measuring section 113 between the entrance 131 that opens in the side section 123 of the measuring section 113 and the first outlet 132 that opens in the side section 124 of the measuring section 113. formed to extend along the The first subpassage 134 is a flow path that extends from the inlet 131 along the flow direction of the gas 2 to be measured in the main passage 22 and connects to the first outlet 132 . The first auxiliary passage 134 takes in the measured gas 2 flowing through the main passage 22 from the inlet 131 and returns the taken-in measured gas 2 from the first outlet 132 to the main passage 22 .

The second sub-passage 135 branches off from the middle of the first sub-passage 134 and extends toward the proximal end of the measuring portion 113 (toward the flange 111 ), and the forward portion 136 is folded back at the proximal end of the measuring portion 113 . and a return path portion 137 extending toward the tip surface portion 125 of the measuring portion 113 and making a U-turn. The outward path portion 136 branches in the middle of the first sub-passage 134 and extends in a direction away from the first sub-passage 134 . Return path portion 137 is folded back at the end of outward path portion 136 to make a U-turn, and extends in a direction approaching first sub-passage 134 . The return path portion 137 connects to a second outlet 133 that opens toward the downstream side of the main passage 22 at a position downstream of the main passage 22 relative to the inlet 131 . The second sub-passage 135 allows the gas to be measured 2 branched from the first sub-passage 134 to pass therethrough and returns it to the main passage 22 from the second outlet 133 . Since the second sub-path 135 has an outward path portion 136 and a return path portion 137 extending along the longitudinal direction of the measuring portion 113, a long path length can be ensured. As a result, even when pulsation occurs in the main passage 22, the physical quantity measuring device 20 allows the flow rate detection element 321 arranged in the second sub passage 135 to be detected in the second sub passage 135 without being significantly affected by the pulsation. can be measured.

The circuit board 300 has a substantially rectangular shape in plan view. In the circuit board 300, the longitudinal direction of the circuit board 300 extends from the base end portion of the measuring portion 113 toward the distal end portion 125, and the lateral direction of the circuit board 300 extends from the side portion 123 to the side portion 124 of the measuring portion 113. It is arranged in the measurement unit 113 so as to extend.

The circuit board 300 is a circuit board on which electronic components can be mounted on both the mounting surface 300a and the mounting surface 300b. A mounting surface 300 a of the circuit board 300 is arranged on the front portion 121 of the measuring portion 113 . A mounting surface 300 b of the circuit board 300 is arranged on the rear surface portion 122 of the measurement unit 113 . On the mounting surface 300a of the circuit board 300, electronic components such as a chip package 310 supporting the flow rate detecting element 321, a temperature sensor 331, a humidity sensor 333 and a pressure sensor 335 are mounted. Electronic components such as an LSI 341 and a microcomputer 343 are mounted on the mounting surface 300 b of the circuit board 300 .

The chip package 310 is mounted on the central portion of the mounting surface 300 a of the circuit board 300 . The chip package 310 has a fixed portion 311 fixed to the central portion of the mounting surface 300 a and a protruding portion 312 protruding from the fixed portion 311 toward the outgoing path portion 136 of the second sub-passage 135 . A flow rate detection element 321 is provided on the projecting portion 312 . The flow rate detection element 321 has a diaphragm-like (thin film-like) detection surface, and this detection surface is exposed to the outward path portion 136 of the second sub-path 135 . The flow rate detection element 321 measures the flow rate of the gas 2 to be measured taken into the outward path portion 136 of the second sub-path 135 .

The temperature sensor 331 is mounted at the end of the mounting surface 300a of the circuit board 300 near the entrance 131. The temperature sensor 331 is arranged in the middle of the temperature detection passage of the measuring section 113 , one end of which is open near the inlet 131 and the other end of which is open to both the front portion 121 and the rear portion 122 . The temperature sensor 331 measures the temperature of the measured gas 2 introduced into the temperature detection passage.

The humidity sensor 333 is mounted on the mounting surface 300a of the circuit board 300 closer to the front end surface portion 125 of the measuring portion 113 than the chip package 310 is. The humidity sensor 333 measures the humidity of the gas 2 to be measured taken in through the window of the measurement unit 113 opening in the back surface 122 .

The pressure sensor 335 is mounted on the mounting surface 300a of the circuit board 300 closer to the base end of the measuring section 113 than the chip package 310 is. The pressure sensor 335 measures the pressure of the gas 2 to be measured taken in from the pressure introduction passage of the measuring section 113 that opens in the middle of the second sub passage 135 .

The LSI 341 and the microcomputer 343 are mounted on the mounting surface 300b of the circuit board 300. The LSI 341 and the microcomputer 343 perform various signal processing and arithmetic processing on the output signals from the flow rate detection element 321, the temperature sensor 331, the humidity sensor 333, or the pressure sensor 335, and measure the electrical signals representing the measurement results of physical quantities. Output a signal. This measurement signal is output to the outside of the physical quantity measuring device 20 from the connector 112 via the wiring pattern of the circuit board 300 , the electrode pads 301 , the wires 350 and the connector terminals 117 . A measurement signal output to the outside of the physical quantity measuring device 20 is input to the control device 4 .

FIG. 6 is an enlarged view of the vicinity of the connector terminal 117 shown in FIG. FIG. 7 is a schematic diagram of a cross section taken along the line AA shown in FIG. FIG. 8 is an enlarged view of a portion surrounded by a dashed line shown in FIG.

The connector terminal 117 is a terminal that outputs a physical quantity measurement signal to the outside. The connector terminal 117 is integrally formed with the housing 100 by insert molding or the like. The connector terminals 117 are partially exposed from the terminal sealing portion 114 of the housing 100 and are sealed in the terminal sealing portion 114 . The connector terminal 117 is made of a plate member made of a conductive material such as phosphor bronze. The linear expansion coefficient of the connector terminal 117 may be 10 ppm/K or more and 30 ppm/K or less, and may be about 20 ppm/K, for example.

The connector terminal 117 has a bonding surface 118 and side surfaces 119, as shown in FIG. The bonding surface 118 is exposed from the terminal sealing portion 114 of the housing 100 and is the surface to which the wire 350 is bonded. Bonding surface 118 contacts encapsulation member 250 . The bonding surface 118 extends in the width direction and the axial direction of the connector terminal 117 . The side surface 119 is a surface continuous with the bonding surface 118 and is a surface sealed with the terminal sealing portion 114 of the housing 100 . The side surface 119 extends in the plate thickness direction and the axial direction of the connector terminal 117 .

The width direction of the connector terminal 117 is the direction orthogonal to the side surface 119 and the width direction of the measuring section 113 . In this embodiment, the width direction of the connector terminal 117 is defined as the X-axis, and the direction from the side surface portion 123 to the side surface portion 124 in the width direction of the measuring portion 113 is defined as the +X-axis direction. The plate thickness direction of the connector terminal 117 is a direction orthogonal to the bonding surface 118 and a direction orthogonal to the longitudinal direction and the lateral direction of the measuring section 113 . In this embodiment, the thickness direction of the connector terminal 117 is the Y-axis, and the direction from the front part 121 to the back part 122 of the directions perpendicular to the longitudinal direction and the lateral direction of the measurement part 113 is the +Y-axis direction. The axial direction of the connector terminal 117 is a direction perpendicular to the width direction and the plate thickness direction of the connector terminal 117 , and is the longitudinal direction of the measuring section 113 . In this embodiment, the axial direction of the connector terminal 117 is defined as the Z axis, and the direction from the proximal end of the measuring part 113 toward the distal surface part 125 in the longitudinal direction of the measuring part 113 is defined as the +Z axis direction.

The connector terminal 117 may be composed of a plurality of connector terminals 117 arranged at intervals in the width direction of the connector terminal 117, as shown in FIGS. The plurality of connector terminals 117 includes a connector terminal 117a closest to the side surface portion 123 in the width direction and a connector terminal 117b closest to the side surface portion 124 in the width direction.

The wire 350 is a bonding wire for connecting the circuit board 300 and the connector terminal 117 by wire bonding. The wires 350 connect the electrode pads 301 on the mounting surface 300b of the circuit board 300 and the bonding surfaces 118 of the connector terminals 117, as shown in FIG. Wire 350 is formed of a linear member made of a metal material such as aluminum or copper. The linear expansion coefficient of the wire 350 may be 10 ppm/K or more and 30 ppm/K or less, and may be about 20 ppm/K, for example.

The sealing member 250 covers the mounting surface 300b of the circuit board 300 exposed from the back surface portion 122 of the measuring portion 113 of the housing 100. The sealing member 250 is formed, for example, by molding a synthetic resin material such as epoxy resin. The coefficient of linear expansion of the sealing member 250 may be 10 ppm/K or more and 30 ppm/K or less, for example, about 20 ppm/K at the glass transition temperature or lower. Sealing member 250 seals wire 350 as shown in FIG. The sealing member 250 contacts the bonding surface 118 of the connector terminal 117 and the terminal sealing portion 114 of the housing 100 .

The terminal sealing portion 114 of the housing 100 is a portion that seals the connector terminal 117 positioned at the proximal end portion of the measuring portion 113 . Housing 100 including terminal sealing portion 114 is formed by, for example, molding a synthetic resin material such as PBT (polybutylene terephthalate) resin. The housing 100 is molded using a resin material having a coefficient of linear expansion greater than that of the sealing member 250 . The coefficient of linear expansion of the housing 100 may be 60 ppm/K or more and 110 ppm/K or less, for example, about 100 ppm/K at the glass transition temperature or lower. The linear expansion coefficient of the housing 100 may be 5 times or more and 6 times or less than the linear expansion coefficient of the sealing member 250 .

The terminal sealing portion 114 has a first surface 115 and a second surface 116, as shown in FIG. The first surface 115 is the surface that contacts the side surface 119 of the connector terminal 117 . The first surface 115 extends in the plate thickness direction and the axial direction of the connector terminal 117 . The second surface 116 is a surface continuous with the first surface 115 and a surface that contacts the sealing member 250 . The second surface 116 extends in the width direction and the axial direction of the connector terminal 117 .

The second surface 116 has an end portion 116 a that is an end portion of the second surface 116 in the width direction of the connector terminal 117 and that is continuous with the first surface 115 . The height of the end portion 116 a of the second surface 116 (position in the plate thickness direction of the connector terminal 117 ) is the same as the height of the bonding surface 118 . That is, the end portion 116 a of the second surface 116 is formed flush with the bonding surface 118 . In other words, the end portion 116 a of the second surface 116 is shaped to be flush with the bonding surface 118 .

In the terminal sealing portion 114 of the housing 100, a molten resin is filled between an upper mold (movable mold) that opens and closes in the plate thickness direction of the connector terminal 117 and a lower mold (fixed mold) that does not move, and is cured. It is molded by Even if the portion corresponding to the bonding surface 118 and the end portion 116a of the molding surface of the upper mold is flattened and brought into contact with the bonding surface 118 for molding, the resin will undergo thermal shrinkage of several percent. The portion 116a is lowered within several tens of micrometers from the bonding surface 118 .

In the present embodiment, the end portion 116a of the second surface 116 and the bonding surface 118 are flush only when the end portion 116a of the second surface 116 and the bonding surface 118 are arranged completely on the same plane. but also includes the following cases: That is, the end portion 116a of the second surface 116 is arranged to be lowered within several tens of μm from the bonding surface 118 in the direction (−Y-axis direction) toward the opposite side of the wire 350 in the plate thickness direction of the connector terminal 117. including cases where It should be noted that the edges of the bonding surface 118 may be sagging when the connector terminals 117 are cut by press working or the like. The end portion 116a of the second surface 116 is formed to be flush with the main portion of the bonding surface 118, which is the majority portion other than the sagging edge portion.

The second surface 116 has an intermediate portion 116b located between the connector terminals 117 adjacent to each other in the width direction of the connector terminals 117 . The intermediate portion 116b of the second surface 116 is formed to be located at a position lower than the end portion 116a of the second surface 116 by a predetermined distance in the direction opposite to the wire 350 in the plate thickness direction of the connector terminal 117. be done. This predetermined distance may be a length equal to or less than 1/2 of the plate thickness of the connector terminal 117, and may be, for example, equal to or greater than 1/3 and equal to or less than 1/2.

The second surface 116 has an inclined surface 116 c that is inclined with respect to the bonding surface 118 . The inclined surface 116c of the second surface 116 is inclined in the direction (-Y-axis direction) toward the side opposite to the wire 350 in the plate thickness direction of the connector terminal 117 as it is separated from the end portion 116a in the width direction of the connector terminal 117. do. Inclined surface 116 c of second surface 116 is formed between end portion 116 a and intermediate portion 116 b in the width direction of connector terminal 117 . Further, the inclined surface 116c of the second surface 116 is formed on the outer portion 116d of the second surface 116 extending from the connector terminal 117a toward the side surface portion 123 in the width direction of the connector terminal 117. As shown in FIG. Similarly, the inclined surface 116c of the second surface 116 is formed on the outer portion 116e of the second surface 116 extending from the connector terminal 117b toward the side surface portion 124 in the width direction of the connector terminal 117. As shown in FIG.

In other words, the second surface 116 located between the adjacent connector terminals 117 has a groove 116f having a V-shaped cross section cut by a plane including the plate thickness direction and width direction of the connector terminal 117 . The depth of the V-shaped groove 116f may be 1/2 or less of the plate thickness of the connector terminal 117, for example, 1/3 or more and 1/2 or less. good.

The effect of this embodiment is demonstrated using FIG.9 and FIG.10.
FIG. 9 is a diagram illustrating a physical quantity measuring device 20 of a comparative example. FIG. 9 is a diagram corresponding to FIG. FIG. 10 is an enlarged view of a portion surrounded by a dashed line shown in FIG. FIG. 10 is a diagram corresponding to FIG.

In the physical quantity measuring device 20 of the comparative example, the second surface 116 has a convex surface 116g in which the heights of the end portion 116a and the intermediate portion 116b are higher than the bonding surface 118. In the physical quantity measuring device 20 of the comparative example, the housing 100 including the terminal sealing portion 114 has a linear expansion coefficient larger than that of the sealing member 250 . Due to the difference in coefficient of linear expansion between the housing 100 and the sealing member 250 , thermal stress is generated in the terminal sealing portion 114 near the interface with the sealing member 250 .

In particular, when the housing 100 is molded using relatively inexpensive PBT resin and the sealing member 250 is molded using epoxy resin, the linear expansion coefficient of the housing 100 is 5 to 6 times that of the sealing member 250. Become. In this case, when a thermal load of −40° C. or more and 130° C. or less is applied to the physical quantity measuring device 20 of the comparative example, the terminal sealing portion 114 of the housing 100 is changed to the sealing member 250 shown in S1 and S2 in FIG. A large thermal stress is generated in the vicinity of the interface with the second surface 116 . Due to the action of this thermal stress, there is a possibility that the connector terminal 117 sealed by the terminal sealing portion 114 and the sealing member 250 are separated. If this peeling is large, the wire 350 sealed by the sealing member 250 will break due to thermal fatigue. That is, it is difficult to ensure the connection reliability of the wire 350 in the physical quantity measuring device 20 of the comparative example.

On the other hand, in the physical quantity measuring device 20 of this embodiment, the height of the end portion 116 a of the second surface 116 is the same as the height of the bonding surface 118 of the connector terminal 117 . That is, the end portion 116 a of the second surface 116 is formed flush with the bonding surface 118 . As a result, the physical quantity measuring device 20 of the present embodiment can reduce the volume of the terminal sealing portion 114 in the vicinity of the interface with the sealing member 250, thereby reducing the amount of thermal deformation of the terminal sealing portion 114. be able to.

Moreover, in the physical quantity measuring device 20 of the present embodiment, the connector terminal 117 hardly restricts the thermal deformation of the terminal sealing portion 114 near the interface with the sealing member 250 . For example, when the second surface 116 has a convex surface 116g as in the physical quantity measuring device 20 of the comparative example, the vicinity of the convex surface 116g of the terminal sealing portion 114 becomes the bonding surface 118 when the terminal sealing portion 114 thermally shrinks. , and thermal contraction near the convex surface 116g is likely to be regulated by the bonding surface 118. On the other hand, in the physical quantity measuring device 20 of the present embodiment, since the height of the end portion 116a of the second surface 116 is the same as the height of the bonding surface 118, the terminal sealing portion near the interface with the sealing member 250 Thermal deformation of 114 is less likely to be restricted by connector terminal 117 .

For this reason, the physical quantity measuring device 20 of the present embodiment does not use an expensive resin material for the housing 100 so that the difference in coefficient of linear expansion from that of the sealing member 250 is small. It is possible to suppress the thermal stress generated in the terminal sealing portion 114 in the vicinity of the interface. The physical quantity measuring device 20 of the present embodiment can suppress separation between the connector terminal 117 and the sealing member 250, and can suppress breakage of the wire 350 due to thermal fatigue. Therefore, the physical quantity measuring device 20 of this embodiment can easily ensure the connection reliability of the wire 350 .

Further, in the physical quantity measuring device 20 of the present embodiment, as the second surface 116 is separated from the end portion 116a in the width direction of the connector terminal 117, the thickness of the connector terminal 117 is increased toward the opposite side of the wire 350 in the thickness direction of the connector terminal 117. incline. That is, the second surface 116 has the inclined surface 116c as described above.

If the second surface 116 is formed in a concave shape that descends stepwise from the end portion 116a toward the intermediate portion 116b, the molding surface of the upper mold has a convex portion corresponding to this concave shape. In this case, if the connector terminal 117 arranged between the upper mold and the lower mold is misaligned, the convex portion of the upper mold tends to bite the connector terminal 117, and defective products are likely to occur. Productivity tends to decrease.

In the physical quantity measuring device 20 of the present embodiment, the second surface 116 has the inclined surface 116c as described above, so the molding surface of the upper mold has an inclined surface corresponding to the inclined surface 116c. Since the molding surface of the upper mold has an inclined surface corresponding to the inclined surface 116c, the molding surface of the upper mold regulates the position of the connector terminal 117 during molding, thereby suppressing displacement. As a result, the physical quantity measuring device 20 of the present embodiment can prevent the connector terminal 117 from getting caught, and can prevent a decrease in productivity. Therefore, the physical quantity measuring device 20 of this embodiment can suppress the production cost of the housing 100 in which the connector terminals 117 are integrally formed.

Moreover, in the physical quantity measuring device 20 of the present embodiment, even when the linear expansion coefficient of the housing 100 is larger than the linear expansion coefficient of the sealing member 250, the heat generated in the terminal sealing portion 114 near the interface with the sealing member 250 is reduced. Stress can be suppressed. The physical quantity measuring device 20 of the present embodiment can suppress separation between the connector terminal 117 and the sealing member 250, and can suppress breakage of the wire 350 due to thermal fatigue.

For this reason, in the physical quantity measuring device 20 of the present embodiment, the second surface 116 has the inclined surface 116c as described above. Thermal stress can be easily suppressed, and connection reliability of the wire 350 can be easily ensured.

In particular, in the physical quantity measuring device 20 of this embodiment, the second surface 116 located between adjacent connector terminals 117 has a V-shaped groove 116f. Analysis of the thermal stress generated near the interface between the terminal sealing portion 114 of the housing 100 and the sealing member 250 in the present embodiment having the V-shaped groove 116f and the comparative example having the convex surface 116g reveals that: The thermal stress of this embodiment was about one-third that of the comparative example. Accordingly, in the physical quantity measuring device 20 of the present embodiment, the thermal stress generated in the terminal sealing portion 114 can be greatly suppressed, and the connection reliability of the wire 350 can be sufficiently secured.

Furthermore, in the physical quantity measuring device 20 of the present embodiment, the depth of the V-shaped groove 116f may be 1/3 or more and 1/2 or less of the plate thickness of the connector terminal 117. When the depth of the V-shaped groove 116f is one-third or more of the plate thickness of the connector terminal 117, the effect of suppressing the thermal stress generated in the terminal sealing portion 114 is large. When the depth of the V-shaped groove 116f is half or less than the plate thickness of the connector terminal 117, the terminal sealing portion 114 can easily secure the amount of resin in the vicinity of the intermediate portion 116b. It becomes easy to secure the strength in the vicinity of the intermediate portion 116b and to fix the connector terminal 117 easily. Therefore, the physical quantity measuring device 20 of the present embodiment can effectively suppress the thermal stress generated in the terminal sealing portion 114 to ensure the connection reliability of the wire 350, and the terminal sealing of the housing 100 can The mechanical reliability of the stop portion 114 can be easily ensured.

Furthermore, in the physical quantity measuring device 20 of the present embodiment, the linear expansion coefficient of the housing 100 may be 5 times or more and 6 times or less than the linear expansion coefficient of the sealing member 250 . That is, the physical quantity measuring device 20 uses a resin material having a coefficient of linear expansion that is 5 to 6 times that of the sealing member 250, such as an example in which PBT resin is used for the housing 100 and epoxy resin is used for the sealing member 250. 100, the thermal stress generated in the terminal sealing portion 114 can be suppressed. As a result, the physical quantity measuring device 20 of the present embodiment can suppress the thermal stress even if a relatively inexpensive resin material is used for the housing 100, so that the connection reliability of the wire 350 can be more easily secured. can do.

Furthermore, in the physical quantity measuring device 20 of the present embodiment, the housing 100 has a front portion 121 in which the

secondary passages

134 and 135 are formed, and a rear portion 122 opposite to the front portion 121 of the housing 100. Two faces 116 are formed on the back portion 122 . That is, in the measuring portion 113 of the housing 100, the second surface 116 is formed on the rear portion 122 opposite to the front portion 121 in which the

sub-passages

134 and 135 are formed.

In the molding die for the housing 100, since the complex-shaped portion of the housing 100 is likely to cling to the die, it is often molded by the lower die, which is a fixed die. If the upper mold is opened while the housing 100 after molding is clinging to the upper mold, the mold for molding the housing 100 needs a complicated mechanism for taking out the housing 100 after molding. . In the housing 100 of this embodiment, the front portion 121 in which the

sub-passages

134 and 135 are formed corresponds to a complicated-shaped portion, so it is preferable to mold the front portion 121 using a lower mold.

In the physical quantity measuring device 20 of the present embodiment, the second surface 116 is formed on the rear surface portion 122 on the side opposite to the front surface portion 121 where the

secondary passages

134 and 135 are formed. As a result, in the physical quantity measuring device 20 of the present embodiment, the front part 121 in which the

secondary passages

134 and 135 are formed is formed by the lower mold, the connector terminals 117 are arranged in the lower mold, and the second surface 116 is formed. can be molded by the upper mold. Therefore, in the physical quantity measuring device 20 of the present embodiment, the housing 100 can be appropriately molded without complicating the mold for molding the housing 100 and the molding process. Therefore, the physical quantity measuring device 20 of the present embodiment can further reduce the production cost of the housing 100, so that the connection reliability of the wire 350 can be more easily ensured.

A modification of the present embodiment will be described with reference to FIGS. 11 and 12. FIG.
FIG. 11 is a diagram illustrating a physical quantity measuring device 20 of a modified example of this embodiment. FIG. 11 is a diagram corresponding to FIG. FIG. 12 is an enlarged view of a portion surrounded by a dashed line shown in FIG. 11. FIG. FIG. 12 is a diagram corresponding to FIG.

In the physical quantity measuring device 20 of this embodiment, as shown in FIGS. 7 and 8, the second surface 116 positioned between adjacent connector terminals 117 has a V-shaped groove 116f. On the other hand, as shown in FIGS. 11 and 12, in the physical quantity measuring device 20 of the modification, the second surface 116 positioned between the adjacent connector terminals 117 may have a flat surface 116h. That is, in the physical quantity measuring device 20 of the modified example, the second surface 116 does not have the inclined surface 116c, and not only the end portion 116a but also the intermediate portion 116b are formed flush with the bonding surface 118. may The fact that the end portion 116a and intermediate portion 116b of the second surface 116 and the bonding surface 118 are flush with each other is defined in the same manner as above.

Also in the physical quantity measuring device 20 of the modified example, thermal stress generated in the terminal sealing portion 114 near the interface with the sealing member 250 can be suppressed, and peeling between the connector terminal 117 and the sealing member 250 can be suppressed. be able to. The physical quantity measuring device 20 of the modified example can suppress breakage of the wire 350 due to thermal fatigue, and can easily ensure the connection reliability of the wire 350 .

[others]
In addition, the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, or replace part of the configuration of each embodiment with another configuration.

2 gas to be measured, 20 physical quantity measuring device, 22 main passage, 100 housing, 115 first surface, 116 second surface, 116 a end, 116 f groove, 117 connector terminal (terminal), DESCRIPTION OF SYMBOLS 118... Bonding surface 119... Side surface 121... Front part 122... Back

part

134, 135... Sub passage 250... Sealing member 310... Chip package (sensor) 331... Temperature sensor (sensor) 333... humidity sensor (sensor), 335 pressure sensor (sensor), 350 wire

Claims

a housing that houses a sensor that measures a physical quantity;
terminals sealed in the housing;
a wire bonded to the terminal;
a sealing member that seals the wire and contacts each of the terminal and the housing;
a coefficient of linear expansion of the housing is greater than a coefficient of linear expansion of the sealing member;
The terminal has a bonding surface to which the wire is bonded and contacts the sealing member, and a side surface continuous with the bonding surface and sealed with the housing,
The housing has a first surface that contacts the side surface of the terminal and a second surface that is continuous with the first surface and contacts the sealing member,
A physical quantity measuring device, wherein an end portion of the second surface that is continuous with the first surface is formed to be flush with the bonding surface.
2. The physical quantity according to claim 1, wherein the second surface is inclined toward the opposite side of the wire in the plate thickness direction of the terminal as it is separated from the end in the width direction of the terminal. measuring device.
The terminal is configured by a plurality of the terminals arranged at intervals in the width direction of the terminal,
The second surface located between the adjacent terminals has a groove having a V-shaped cross section cut by a plane including the plate thickness direction and the width direction of the terminal. The physical quantity measuring device according to claim 2.
The physical quantity measuring device according to claim 3, wherein the depth of the groove is one-third or more and one-half or less of the plate thickness of the terminal.
The physical quantity measuring device according to claim 1, wherein the linear expansion coefficient of the housing is 5 times or more and 6 times or less than the linear expansion coefficient of the sealing member.
Having a secondary passage that takes in a part of the gas to be measured flowing through the main passage,
The housing has a front portion in which the secondary passage is formed, and a back portion of the housing opposite to the front portion,
The physical quantity measuring device according to claim 1, wherein the second surface is formed on the back surface portion.