WO2019176509A1 - Electrical connection apparatus - Google Patents

Abstract

Provided is an electrical connection apparatus in which warping of two electroconductive plates where an electronic component is mounted and of a resin part between the electroconductive plates is suppressed, cracking of a solder joining portion is suppressed, and faults in a switching element are suppressed, said defects being caused by environmental temperatures. The present invention is provided with: a switching element (13); two first electroconductive plates (113, 113); a resin part (114) disposed between the first electroconductive plates (113, 113) so as to be formed integrally with the first electroconductive plates (113, 113); an electronic component (14) of which two terminals (141, 141) are connected to the first electroconductive plates (113, 113), the electronic component (14) detecting a physical quantity pertaining to the switching element (13); and reinforcing plates (111, 112) formed integrally with the resin part (114), the reinforcing plates (111, 112) being disposed along a direction in which the electronic component (14) is connected to the first electroconductive plates (113, 113).

Description

Electrical connection device

The present invention relates to an electrical connection device.

An electrical connection device in which a conductive plate (also called a bus bar) that constitutes a circuit for conducting a relatively large current is fixed to a substrate on which a conductive pattern that constitutes a circuit that conducts a relatively small current is formed. (For example, refer to Patent Document 1).

The electrical connection device includes, for example, an FET (Field Effect Transistor) as a switching element, a drive circuit that drives the FET, and a control board on which a control circuit that gives an on / off signal to the drive circuit is mounted. .
As an electrical connection device, for example, an insert bus bar structure has been studied in a high-current relay. The insert bus bar refers to a structure in which a conductive plate is insert-molded.
When a current flows through the FET, it generates heat, which may cause the FET to fail. In order to detect the ambient temperature of the FET, in the electrical connection device, a thermistor is disposed near the FET. Since the resistance value of the thermistor varies depending on the temperature, the control circuit monitors the resistance value of the thermistor and outputs an off signal to the drive circuit when it is determined that the temperature of the FET is equal to or higher than the threshold value.

JP 2011-29313 A

When the above-described insert bus bar structure is applied, a resin portion is interposed between two conductive plates. When the thermistor is a chip type, it is mounted on two conductive plates and a resin portion interposed between the conductive plates.
The conductive plate is made of a metal material such as copper or a copper alloy, and when the environmental temperature changes, the resin portion and the conductive plate may warp due to the difference in linear expansion coefficient between the resin portion and the conductive plate. When the resin portion and the conductive plate are warped, stress is generated at the solder joint portion of the thermistor mounted on the conductive plate, and there is a possibility that a crack may occur. If a crack occurs, the temperature of the FET cannot be monitored.

An object of the present invention is to suppress two conductive plates on which electronic components are mounted and a resin portion between the conductive plates from being warped due to environmental temperature, and to suppress occurrence of cracks in a solder joint portion. An object of the present invention is to provide an electrical connection device in which the failure of the device is suppressed.

The electrical connection device according to an aspect of the present invention is disposed so as to integrate the two first conductive plates between the switching element, the two first conductive plates, and the two first conductive plates. A resin part and two terminals are connected to each first conductive plate, an electronic component for detecting a physical quantity related to the switching element, and an integral part of the resin part, and the electronic component is connected to the two first conductive plates And a reinforcing plate arranged along the connected direction.

According to this aspect, since the reinforcing plate is provided along the direction in which the resin portion and the first conductive plate easily warp due to the difference in the linear expansion coefficient when the environmental temperature changes, the resin portion and the first conductive The warpage of the plate is suppressed. Since the occurrence of stress in the solder joints of electronic parts is suppressed and cracks are suppressed, the joint reliability is good, the electronic parts can detect the physical quantities well, and the failure of the switching element is suppressed. The

It is a perspective view of the electrical connection apparatus concerning an embodiment. It is a top view of an electrical connection apparatus. FIG. 3 is a sectional view taken along line III-III in FIG. 2. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2.

[Description of Embodiment of the Present Invention]
First, embodiments of the present invention will be listed and described. You may combine arbitrarily at least one part of embodiment described below.

(1) In the electrical connection device according to one aspect of the present invention, the two first conductive plates are integrated between the switching element, the two first conductive plates, and the two first conductive plates. The arranged resin part, two terminals are connected to each first conductive plate, an electronic component for detecting a physical quantity related to the switching element, and the resin part are integrated, and the electronic component is the two first conductive plates. And a reinforcing plate arranged along a direction connected to the conductive plate.

In this aspect, when the environmental temperature changes, the reinforcing plate is provided along the direction in which the resin portion and the first conductive plate easily warp due to the difference in linear expansion coefficient. Warpage of the conductive plate is suppressed. Since the occurrence of stress in the solder joints of electronic parts is suppressed and cracks are suppressed, the joint reliability is good, the electronic parts can detect the physical quantities well, and the failure of the switching element is suppressed. The

(2) An electrical connection device according to an aspect of the present invention includes two second conductive plates, and the switching element is connected to the two second conductive plates, and the electrical connection between the two second conductive plates. The connection is cut off and the connection is cut off, and the reinforcing plate is a second conductive plate.

In this aspect, since the reinforcing plate and the second conductive plate are shared, the material cost can be reduced, and the electrical connection device can be reduced compared to the case where the reinforcing plate and the second conductive plate are separated. The surface area can be reduced.

(3) In the electrical connection device according to one aspect of the present invention, the thickness of the reinforcing plate is greater than the thickness of the first conductive plate.

In this aspect, the warp of the resin portion and the second conductive plate is suppressed satisfactorily.

Hereinafter, the present invention will be specifically described with reference to the drawings illustrating embodiments thereof.
(Embodiment)
1 is a perspective view of an electrical connection device 1 according to the embodiment, FIG. 2 is a plan view thereof, FIG. 3 is a sectional view taken along line III-III in FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV in FIG. The electrical connection device 1 is arranged in a power supply path between a power source such as a battery provided in the vehicle and a load composed of an on-vehicle electrical component such as a lamp and a wiper or a motor.

In the embodiment, the “front”, “rear”, “left”, “right”, “upper”, and “lower” of the electrical connecting device 1 are changed according to the front, rear, left, and right directions shown in FIGS. Define. Hereinafter, the configuration of the electrical connection device 1 will be described using the front, rear, left, and right directions defined by FIGS. 1 to 3. The front, rear, left and right directions in FIGS. 1 to 4 are directions shown for convenience, and the front, rear, left and right, and upper and lower directions when the electrical connecting device 1 is attached to a mounting site such as a vehicle. It is not shown.

The electrical connection device 1 includes a circuit unit 10 and a housing unit 20 that houses the circuit unit 10. The circuit unit 10 includes conductive plates 111, 112, 113, a FET 13 as a switching element, a drive circuit for driving the FET 13, and a control board 12 on which a control circuit for giving an on / off signal to the drive circuit is mounted, and an FET 13 And a thermistor 14 for detecting the temperature. The FET 13 is, for example, a surface mount type power MOSFET. The drive circuit and the control board may be mounted on different boards.

As shown in FIGS. 1 and 2, the conductive plate 111 is disposed in a rectangular region that occupies the right and front portions of the exposed region of the upper surface of the circuit unit 10.
The conductive plate 113 has a small rectangular shape, and a plurality of conductive plates 113 are provided at intervals along the upper and left sides of the conductive plate 111.
The conductive plate 112 is provided in a portion where the conductive plate 113 is not provided in the left side portion and the rear side portion of the exposed region of the upper surface of the circuit unit 10.
1 and 2 show a configuration in which only one FET 13 is mounted for simplification, a plurality of FETs 13 may be mounted.

The FET 13 includes a drain terminal 131 on the right side of the element body, and a source terminal 132 and a gate terminal 133 on the left side of the element body. The drain terminal 131 is soldered to the conductive plate 111 and the source terminal 132 is soldered to the conductive plate 112. The conductive plate 111 and the conductive plate 112 are made of a metal material such as copper or a copper alloy, and have a thickness of about 1.0 to 2.0 mm, for example.

The gate terminal 133 of the FET 13 is soldered to the conductive plate 113. The conductive plate 113 is made of a metal material such as copper or a copper alloy, and has a thickness of about 0.64 mm, for example.
The ratio of the thickness of the conductive plate 111 or the conductive plate 112 to the thickness of the conductive plate 113 is preferably 1.5 to 3.2.

As shown in FIG. 3, unlike the conductive plate 111 and the conductive plate 112, the conductive plate 113 is exposed on the upper surface of the circuit unit 10 and is connected to the gate terminal 133 and the terminal connection unit 113 a. A board connecting portion 113b that is bent downward from one end and connected to the control board 12. The board connecting part 113b has a tapered shape. In the present embodiment, the lower end of the board connecting portion 113b is inserted into the through hole 121 provided in the control board 12, the conductive material is filled in the through hole 121, and the conductive plate 113 is electrically connected to the control board 12. is doing.

The conductive plate 111, the conductive plate 112, and the conductive plate 113 constitute a composite molded body 11 integrated with an insulating resin material. The composite molded body 11 is manufactured by insert molding using an insulating resin material such as phenol resin or glass epoxy resin. The resin portion 114 formed of an insulating resin material is joined to each conductive plate to integrate them, and is interposed between the conductive plates to insulate each conductive plate. In the present embodiment, the composite molded body 11 is formed by insert molding so that the conductive plate 111, the conductive plate 112, the terminal connection portion 113a of the conductive plate 113, and the exposed surface (the upper surface in the drawing) of the resin portion 114 are flush with each other. Mold.

The control board 12 has, for example, a rectangular insulating board. The control circuit (not shown) and the drive circuit (not shown) are mounted on the lower surface of the insulating substrate. The control circuit outputs an on / off signal to the drive circuit and adjusts the voltage output from the drive circuit to the gate terminal 133, whereby conduction / non-conduction between the drain terminal 131 and the source terminal 132 is controlled. As described above, the lower end of the board connecting portion 113b is inserted into the through hole 121 of the control board 12 and connected to the wiring pattern, whereby the FET 13 mounted on the upper face of the electrical connecting apparatus 1 and the lower face of the control board 12 are connected. Conduction is established between the mounted drive circuit.

The housing part 20 is a resin case with an upper end surface and a lower end surface opened. The accommodating portion 20 includes a peripheral wall portion 201 that surrounds the peripheral edges of the composite molded body 11 and the control board 12 accommodated therein in the left-right direction and the front-rear direction. The peripheral wall 201 has an opening 202 formed at the upper end so as to be slightly larger than the peripheral edge of the composite molded body 11 in the left-right direction and the front-rear direction. On the inner peripheral surface on the upper end side of the peripheral wall portion 201, a rib 203 is provided so as to protrude inward. The accommodating part 20 accommodates the circuit part 10 which integrated the composite molded object 11 and the control board 12 inside by supporting the peripheral part of the composite molded object 11 from the lower surface side by the rib 203. FIG.

The FET 13 is mounted on the exposed surface of the composite molded body 11 by, for example, a reflow method.
After the solder material is applied or printed on the joint portions of the conductive plates 111, 112, and 113, the FET 13 is placed on the conductive plate 111, heated to melt the solder, and then solidified to form a drain terminal. 131 is joined to the conductive plate 111, and the gate terminal 133 and the source terminal 132 are joined to the conductive plate 113 and the conductive plate 112, respectively, across the resin portion 114.

As described above, since the FET 13 is a heating element, there is a risk of failure. In order to detect the ambient temperature of the FET 13, a thermistor 14 is disposed near the FET 13.
As shown in FIG. 4, the thermistor 14 has a rectangular parallelepiped shape, and has terminals 141 and 141 at both ends in the longitudinal direction.
The terminals 141 and 141 are soldered to the two conductive plates 113 and 113 provided at the left end of the upper side of the conductive plate 111 (see FIGS. 1 and 2).
Terminals 141 and 141 are arranged on the upper side of the conductive plates 113 and 113, solder material is disposed between the terminals 141 and 141 and the conductive plates 113 and 113, reflow processing is performed, and the solder material is melted and then solidified. Thereby, the joining parts 142 and 142 are formed. 1 and 2, the joint 142 is omitted.

Similarly to the above, the conductive plate 113 is inserted into the through hole 122 provided in the control substrate 12 and the conductive material is filled in the through hole 122 so that the conductive plate 113 is connected to the control substrate 12. Is electrically connected to the control circuit.
Since the resistance value of the thermistor 14 varies depending on the temperature, the control circuit monitors the resistance value of the thermistor 14 and outputs an off signal to the drive circuit if it is determined that the temperature of the FET 13 is equal to or higher than the threshold value.

When the environmental temperature rises, for example, the resin portion 114 between the conductive plates 113 and 113 expands, and an upward force shown in FIG. 4 works. Stress is generated on the conductive plates 113 and 113 on both sides, and the resin portion 114 on the lower side of the conductive plates 113 and 113 extends in the left-right direction, so that force is applied to the conductive plates 113 and 113 obliquely downward. The conductive plates 113 and 113 and the resin portion 114 are warped, and there is a possibility that cracks may occur at the joint portions 142 and 142.

In this embodiment, as shown in FIGS. 1 and 2, the conductive plates 111 and 112 exist in parallel to the direction in which the thermistor 14 is connected to the conductive plates 113 and 113, and the left and right sides of the conductive plates 113 and 113 and A conductive plate 112 exists on the right side. Since the conductive plates 111, 112, and 113 are integrated with the resin portion 114, the region where the thermistor 14 is mounted is surrounded by a rigid reinforcing plate. Therefore, the warp of the resin portion 114 and the conductive plate 113 in the region is suppressed, and the occurrence of stress in the joint portion 142 of the thermistor 14 and cracking is suppressed.
Similarly, when the environmental temperature decreases and the resin portion 114 contracts, warping of the conductive plate 113 and the resin portion 114 is similarly suppressed.

In this embodiment, since the reinforcing plate for suppressing warpage and the conductive plate constituting the electric circuit are shared, the material cost can be reduced, and the reinforcing plate and the conductive plate are separated. In comparison, the surface area of the electrical connecting device can be reduced.

Further, in the present embodiment, since the thickness of the conductive plate 112 is thicker than the thickness of the conductive plate 113, the warp of the resin portion 114 and the conductive plate 113 is suppressed satisfactorily. By making the plate thickness of the conductive plate 112 and the conductive plate 111 thicker than the plate thickness of the conductive plate 113, a power source such as a battery provided in the vehicle and a load composed of an on-vehicle electrical component such as a lamp and a wiper or a motor or the like It can also handle large currents flowing in between.

In this embodiment, since the connection reliability of the thermistor 14 is good, the temperature change of the FET 13 can be monitored well, and the failure of the FET 13 is well suppressed.

It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined not by the above-described meaning but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.
For example, it is not limited when the conductive plate 112 also serves as a reinforcing plate.
Further, the reinforcing plate is not limited to the case where it is provided so as to surround the thermistor 14. The reinforcement plate should just be arrange | positioned along the direction where the thermistor 14 is connected to the electrically conductive plates 113 and 113 at least.
And an electronic component is not limited to a thermistor, What is necessary is just to detect the physical quantity of FET13.
Furthermore, the electrical connection device 1 can be used for a large current power control unit such as a DC voltage converter, an AC / DC converter, a DC / AC inverter, and the like.

DESCRIPTION OF SYMBOLS 1 Electrical connection apparatus 10 Circuit part 11 Composite molded object 12 Control board 13 FET
14 Thermistor 141 Terminal 142 Joining portion 20 Housing portion 111, 112, 113 Conductive plate 113a Terminal connecting portion 113b Substrate connecting portion 114 Resin portion 121, 122 Through hole 131 Drain terminal 132 Source terminal 133 Gate terminal 201 Peripheral wall portion 202 Opening portion 203 Rib

Claims (3)

A switching element;
Two first conductive plates;
A resin portion disposed between the two first conductive plates so as to integrate the two first conductive plates;
Two terminals are connected to each first conductive plate, and an electronic component for detecting a physical quantity related to the switching element;
An electrical connection device comprising: a reinforcing plate that is integrated with the resin portion and disposed along a direction in which the electronic component is connected to the two first conductive plates. Comprising two second conductive plates;
The switching element is connected to the two second conductive plates, performs electrical connection between the two second conductive plates, and interrupts the connection,
The electrical connection device according to claim 1, wherein the reinforcing plate is a second conductive plate. The electrical connection device according to claim 1, wherein a thickness of the reinforcing plate is thicker than a thickness of the first conductive plate.

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