JP6075637B2 - Circuit structure and inlay - Google Patents

Description

  The present invention relates to a circuit structure and an inlay.

  Conventionally, a technique in which an inlay is press-fitted into a through hole of a printed board is known. The following Patent Document 1 includes three layers of resin layers, a substrate having two layers of thick copper laminated alternately and having a through hole, and a copper inlay as a heat transfer member press-fitted into the through hole of the substrate. A printed circuit board provided is described.

JP 2011-159727 A

  By the way, in patent document 1, although the copper inlay is press-fitted into the printed circuit board, there is a concern that a stress is generated in the printed circuit board due to the pressure caused by the press-fitting of the copper inlay, causing a problem in the printed circuit board or a circuit on the printed circuit board. .

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a circuit structure and an inlay that can relieve stress generated in a substrate due to press-fitting of the inlay. .

The present invention is a circuit structure including a substrate having a conductive path and a press-fitting hole, an inlay press-fitted into the press-fitting hole, and an electronic component mounted on the substrate, and the press-fitting hole in the inlay The outer peripheral surface in contact with the inner wall is provided at a position different from the high contact pressure portion that contacts the inner wall of the press-fitting hole and applies pressure to the inner wall, and the high contact pressure portion in the circumferential direction of the outer peripheral surface, A low contact pressure portion having a lower pressure applied to the inner wall of the press-fitting hole than the high contact pressure portion, and the inlay is press-fitted into the press-fitting hole by providing a notch of a predetermined depth from the outer peripheral surface. In this case, it elastically contracts to generate an elastic repulsive force .

The present invention provides an inlay that is press-fitted into a press-fitting hole of a substrate having a conductive path, and an outer peripheral surface that is in contact with an inner wall of the press-fitting hole is in contact with the inner wall of the press-fitting hole to apply pressure to the inner wall. A pressure contact portion and a low contact pressure portion provided at a position different from the high contact pressure portion in the circumferential direction of the outer peripheral surface, and having a lower pressure applied to the inner wall of the press fit hole than the high contact pressure portion , By providing a notch with a predetermined depth from the outer peripheral surface, the elastic retraction force is generated by elastic contraction at the time of press-fitting into the press-fitting hole .

According to the above configuration, the outer peripheral surface of the inlay includes the low contact pressure portion that is lower in pressure applied to the inner wall of the press-fit hole than the high contact pressure portion that contacts the inner wall of the press-fit hole and applies pressure to the inner wall. In comparison with the case where a high pressure is applied to the inner wall by using the entire circumference of the outer peripheral surface as a high contact pressure portion at the time of press-fitting, it is possible to relieve the stress applied to the substrate by press-fitting the inlay.
Further, since the inlay is elastically deformed, it is possible to satisfactorily connect to the substrate while relaxing the stress.

In addition to the above configuration, the following configuration is preferable.
The press-fitting hole has a circular shape, and the low contact pressure portion has a smaller diameter from the axial center than the high contact pressure portion.
If it does in this way, the stress at the time of press-fitting in a circular press-fit hole can be relieved.

The board is a printed board in which a conductive path pattern is formed on an insulating plate, and the inlay is connected to the conductive path of the printed board.

A bus bar made of plate-like metal is overlaid on the printed circuit board, and the inlay is connected to the bus bar.

  According to the present invention, it is possible to relieve the stress generated in the substrate due to the press-fitting of the inlay.

Sectional drawing which shows the circuit structure of the reference example 1. Plan view showing circuit board Top view showing the bus bar Top view showing inlay The figure explaining the process of press-fitting the inlay into the press-fitting hole of the circuit board Front view showing a circuit board with an inlay press-fitted The figure explaining the process of putting the circuit board in which the inlay was press-fitted on the bus bar Sectional drawing which shows the state with which the circuit board and the bus bar were piled up The top view which shows the inlay of Embodiment 1 . The figure explaining the process of press-fitting the inlay into the press-fitting hole of the circuit board Front view showing a circuit board with an inlay press-fitted

< Reference Example 1>
A circuit structure 10 of Reference Example 1 will be described with reference to FIGS. 1 to 8. Hereinafter, the vertical direction and the horizontal direction will be described with reference to the direction of FIG.

(Circuit structure 10)
As shown in FIG. 1, the circuit structure 10 includes a circuit board 11, a plurality of (three in this reference example ) bus bars 13A to 13C stacked on the circuit board 11, and a plurality (four in this reference example ). Inlays 16A and 16B and a plurality of electronic components 17A and 17B mounted on the upper surface 11A of the circuit board 11 are provided.

(Circuit board 11)
As shown in FIG. 2, the circuit board 11 is a printed board having a substantially rectangular shape that is long in the left-right direction. The circuit board 11 has a conductive path (made of a conductive material such as copper foil) on an upper surface 11A of an insulating board made of an insulating material. (Not shown) is formed. The circuit board 11 is provided with a plurality of (four in this reference example ) press-fitting holes 12A, 12B into which the inlays 16A, 16B are press-fitted side by side. The diameters of the press-fit holes 12A and the press-fit holes 12B are different depending on the sizes of the inlays 16A and 16B.

(Bus bar 13A-13C)
As shown in FIG. 3, the plurality of bus bars 13 </ b> A to 13 </ b> C are both formed by punching a metal plate material such as copper or a copper alloy into a predetermined shape by a press machine, and different areas of the circuit board 11 with a gap therebetween. Is superimposed on. The bus bars 13A to 13C are formed with a plurality of (four in this reference example ) perfectly circular press-fit holes 14A and 14B through which the inlays 16A and 16B are press-fitted.

  The positions of the press-fit holes 14A and 14B are formed at positions that are continuous with the corresponding press-fit holes 12A and 12B of the circuit board 11. The diameters of the press-fit holes 14A and 14B are substantially the same as the diameters of the corresponding press-fit holes 12A and 12B. The upper surfaces of the bus bars 13A to 13C are bonded to the circuit board 11 with an adhesive (not shown).

  The bus bars 13A to 13C are energized with a relatively large current for driving loads such as external on-vehicle electrical components and vehicle motors, while the control circuit is moved in the conductive path of the circuit board 11. A relatively small control current is applied.

(Inlay 16A, 16B)
The inlays 16A and 16B are both made of a metal (for example, copper, copper alloy, etc.) as a whole, and as shown in FIGS. 4 and 5, are substantially cylindrical (coin-like) with a small vertical thickness (axial direction). I am doing.

The outer dimensions of the inlay 16A (16B) differ depending on the angle about the axis A1. Thereby, the arc-shaped high contact pressure portion 21 having a constant diameter B1 from the axis A1 and the high contact pressure portion 21 are provided on the outer peripheral surface 20 of the inlay 16A (16B) at different positions in the circumferential direction. A linear low contact pressure portion 22 having a smaller diameter from the axial center A1 than the high contact pressure portion 21 is provided.
A diameter B1 from the axis A1 of the high contact pressure portion 21 is slightly larger than a diameter of the press-fit holes 12A and 12B (a diameter that can be press-fit into the press-fit holes).

In this reference example , the high contact pressure portion 21 and the low contact pressure portion 22 are alternately arranged in the circumferential direction, and both are intermediate at an angle of every 120 degrees (the middle of the low contact pressure portion 22 has an axis A1. The high contact pressure portion 21 formed so that the intersection point 22A) of the line segment orthogonal to the surface of the low contact pressure portion 22 has a circular outer periphery with a constant diameter from the axis A1, The low contact pressure portion 22 is formed by cutting the outer peripheral edge linearly along the high contact pressure portion 1.

  5 and 6, when the inlay 16A (16B) is press-fitted into the press-fitting hole 12A (12B), the high contact pressure portion 21 can be fixed to the inner wall of the press-fitting hole 12A (12B). The pressure applied to the low contact pressure portion 22 is lower than the high contact pressure portion 21 to the inner wall of the press-fitting hole 12A (12B). Or, no pressure is applied without contacting the inner wall of the press-fitting hole 12A (12B). Thereby, the high contact pressure portion 21 can securely fix the press-fit holes 12A and 12B to the inner wall, and the low contact pressure portion 22 can relieve the stress applied to the circuit board 11.

  The inlays 16 </ b> A and 16 </ b> B are press-fit into the press-fit holes 14 </ b> A and 14 </ b> B of the bus bars 13 </ b> A to 13 </ b> B and are fixed by soldering. The connection of the inlays 16A and 16B to the conductive path of the circuit board 11 is made, for example, when the conductive paths of the circuit board 11 are led out (exposed) into the press-fitting holes 12A and 12B and the inlays 16A and 16B are press-fitted. Connected. For example, the inlays 16A and 16B are soldered to the conductive paths of the circuit board 11, or the end faces of the inlays 16A and 16B and the conductive paths on the surface of the circuit board 11 are connected by lead wires. May be.

  As shown in FIG. 1, the upper surfaces 15A of the inlays 16A and 16B press-fitted into the press-fitting holes 12A, 12B, 14A and 14B are substantially flush with the upper surface 11A of the circuit board 11, and the lower surfaces 15B of the inlays 16A and 16B are It becomes flush with the lower surface 13D of the bus bars 13A to 13C.

(Electronic components 17A, 17B)
The electronic components 17A and 17B are heat-generating components that are composed of semiconductor switching elements such as FETs, for example, and generate heat in response to energization current. The electronic components 17A and 17B include a main body 18 having a box-shaped package and a plurality of terminals 19.

  The electronic component 17B includes a base-like terminal 19 connected to the inlay 16A and a terminal 19 connected to the inlay 16B press-fitted into the bus bar 13C on the bottom surface of the main body 18. Each terminal 19 is connected to the upper surface 15A of the inlays 16A and 16B or a printed wiring path of the circuit board 11 (not shown) by a known method such as soldering.

(Manufacturing process)
An example of the manufacturing process of the circuit structure 10 will be described.
The axial ends of the inlays 16A and 16B are press-fitted into the press-fitting holes 12A and 12B of the circuit board 11, adhesive is applied to the circuit board 11 or the bus bars 13A to 13C, and the inlays 16A and 16B protrude from the circuit board 11 The portion is press-fitted into the press-fitting holes 14A and 14B, and the circuit board 11 and the bus bars 13A to 13C are overlapped and bonded (FIGS. 7 and 8).
In addition to the connection by press-fitting, the gaps between the press-fitting holes 12A, 12B, 14A, 14B and the inlays 16A, 16B are soldered to electrically connect the conductive paths of the inlays 16A, 16B and the circuit board 11 and the bus bars 13A to 13C. You may make it connect to.

  Next, the circuit components 10 are formed by mounting the electronic components 17A, 17B and the like on the upper surface 11A of the circuit board 11 and mounting the electronic components 17A, 17B on the conductive path by, for example, reflow soldering (FIG. 1). ).

According to the above reference example , the following operations and effects can be achieved.
According to this reference example , the outer peripheral surface 20 in contact with the inner walls of the press-fitting holes 12A and 12B in the inlays 16A and 16B has a lower pressure contact portion that has a lower pressure applied to the inner walls of the press-fitting holes 12A and 12B than the high contact pressure portion 21. 22 is provided at a position different from the high contact pressure portion 21 in the circumferential direction of the outer peripheral surface 20. As a result, the stress applied to the circuit board 11 by the press-fitting of the inlays 16A and 16B is compared with the case where a higher pressure is applied to the inner walls of the press-fitting holes 12A and 12B all around the outer peripheral surface 20 when the inlays 16A and 16B are press-fitted. It can be mitigated.

The inlays 16 </ b> A and 16 </ b> B are press-fitted into the circular press-fitting holes 12 </ b> A and 12 </ b> B, and the low contact pressure portion 22 has a smaller diameter from the axis A <b> 1 than the high contact pressure portion 21.
If it does in this way, the stress at the time of press-fitting in circular press-fit holes 12A and 12B can be relieved.

The circuit board 11 is a printed board having a conductive path pattern formed on an insulating plate, and the inlays 16A and 16B are connected to the conductive path of the printed board.
As a result, it is possible to prevent problems caused by the stress generated on the printed circuit board which is weaker than the bus bar substrate.

Further, bus bars 13A to 13C made of plate-like metal are stacked on the printed circuit board, and the inlays 16A and 16B are connected to the bus bars 13A to 13C.
Thereby, it is possible to energize the bus bars 13A to 13C for a large current such as a vehicle electrical component or a load of a motor, and a small current such as a control current to energize the conductive path of the circuit board 11. become.

<Embodiment 1 >
The first embodiment will be described with reference to FIGS. 9 to 11. In the first embodiment, the inlay 23 is provided with a cut 23A so as to be elastically deformable. In the following, the same components as those in Reference Example 1 are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 9 and 10, the inlay 23 has a high contact pressure portion 24 having a circular outer periphery (arc) having a constant diameter from the axis A <b> 2 and an outer diameter of the high contact pressure portion 24. And a low contact pressure portion 25 having an outer diameter.
The low contact pressure portion 25 is formed by providing a pair of cuts 23A having a predetermined depth from the outer peripheral surface 20 of the inlay 23 toward the axial center A2.
The low contact pressure portion 25 does not contact the inner wall of the press-fitting hole 12A (12B) and therefore does not apply pressure to the inner wall of the press-fitting hole 12A (12B).

  The pair of cuts 23A is formed at an angle of 180 degrees with the axis A2 as the center, has a groove-like gap with a constant width dimension, and the groove bottom that is the back end is rounded. .

10 and 11, when the inlay 23 is press-fitted into the press-fitting hole 12A (12B), the high contact pressure portion 24 applies pressure to the inner wall of the press-fitting hole 12A (12B), and the low contact Since the pressure applied to the inner wall of the press-fitting hole 12A (12B) is lower than that of the high contact pressure part 24, the pressure part 25 reliably fixes the press-fitting hole 12A (12B) to the inner wall, The stress applied to the circuit board 11 can be relaxed by the low contact pressure portion 25.
Further, the inlay 23 is provided with a notch 23A having a predetermined depth from the outer peripheral surface 20, so that the inlay 23 is elastically contracted during press-fitting into the press-fitting holes 12A and 12B, thereby generating an elastic repulsive force.
Thus, when the inlay 23 is press-fitted into the press-fitting hole 12A (12B), the inlay 23 comes into contact with the inner walls of the press-fitting holes 12A and 12B and elastically deforms, thereby relaxing the stress generated in the circuit board 11 and Since the good contact pressure with the conductive path led out to the press-fitting hole 12A (12B) can be secured by the elastic repulsive force 23, the inlay 23 and the circuit board 11 can be connected well.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the reference examples and embodiments described above, the inlays 16A, 16B, and 23 are press-fitted into the circuit board 11 and the bus bars 13A to 13C, which are printed boards. It is good also as a structure press-fit only in one side of 13C (bus-bar board | substrate). In this case, on the side where the inlays 16A, 16B, and 23 of the circuit board 11 and the bus bars 13A to 13C are not press-fitted, for example, an insertion hole having a diameter larger than that of the press-fitting holes 12A, 12B, 14A, and 14B is provided. , 16B, 23 may be inserted with a gap.

(2) In the above reference examples and embodiments, the press-fit holes 12A and 12B have a perfect circle shape, but are not limited thereto. For example, it may be a circular shape such as an oval shape or an oval shape, or a rectangular press-fit hole. In addition, the shapes of the inlays 16A, 16B, and 23 are not limited to the perfect circle shape (the high contact pressure portion), and may be a circular shape such as an oval shape or an elliptical shape, High contact pressure part) is also possible. Also, for inlays other than the perfect circle corresponding to the shape of the press-fitting hole other than the perfect circle shape, the low contact pressure portion whose diameter from the shaft center is smaller than that of the high contact pressure portion, as in the above reference example and embodiment. The low contact pressure portion may apply a lower pressure to the inner wall of the press-fitting hole than the high contact pressure portion.

(3) In the reference example and the embodiment described above, the outer diameter of the low contact pressure portions 22 and 25 is smaller than the outer diameter of the high contact pressure portions 21 and 24, but is not limited thereto. The outer diameter of the low contact pressure portion, which is lower in pressure applied to the inner wall of the press-fitting hole than the high contact pressure portion, may be larger than the outer diameter of the high contact pressure portion. For example, the short diameter side from the axial center of the oval inlay may be the high contact pressure portion, and the long diameter side from the axial center may be the low contact pressure portion.

(4) The number of press-fitting holes and inlays in the circuit structure 10 is not limited to the numbers in the reference example and the embodiment, and may be other numbers.
(5) The circuit board 11 may be a multilayer board in which one or a plurality of conductive paths are laminated.

(6) The pressure applied by the low contact pressure portion to the inner walls of the press-fit holes 12A and 12B only needs to be lower than that of the high contact pressure portion, and the low contact pressure portion contacts the inner walls of the press-fit holes 12A and 12B and applies a low pressure. The low contact pressure portion may not contact the inner walls of the press-fit holes 12A and 12B, and the low contact pressure portion may not apply pressure to the inner walls of the press-fit holes 12A and 12B.

DESCRIPTION OF SYMBOLS 10: Circuit structure 11: Circuit board 12A, 12B: Press-fit hole 13A-13C: Bus bar 14A, 14B: Press-fit hole 16A, 16B, 23: Inlay 17A, 17B: Electronic component 20: Outer peripheral surface 21, 24: High contact pressure Portions 22 and 25: Low contact pressure portion

Claims (6)

A substrate having a conductive path and a press-fit hole;
An inlay that is press-fitted into the press-fitting hole;
An electronic component mounted on the substrate, comprising:
The outer peripheral surface in contact with the inner wall of the press-fitting hole in the inlay is
The high contact pressure portion that contacts the inner wall of the press-fitting hole and applies pressure to the inner wall, and the high contact pressure portion in the circumferential direction of the outer peripheral surface are provided at different positions, and the press-fitting is more than the high contact pressure portion. A low contact pressure portion having a low pressure applied to the inner wall of the hole ,
The inlay is a circuit configuration body in which an incision having a predetermined depth is provided from the outer peripheral surface, thereby elastically contracting and generating an elastic repulsion when the press-fitting into the press-fitting hole . The press-fitting hole is circular,
The circuit configuration body according to claim 1, wherein the low contact pressure portion has a smaller diameter from an axial center than the high contact pressure portion. The circuit structure according to claim 1 , wherein the board is a printed board in which a conductive path pattern is formed on an insulating plate, and the inlay is connected to the conductive path of the printed board . The circuit structure according to claim 3, wherein a bus bar made of a plate-like metal is overlaid on the printed board, and the inlay is connected to the bus bar . An inlay that is press-fitted into a press-fitting hole of a substrate having a conductive path,
The outer peripheral surface in contact with the inner wall of the press-fitting hole is
A high contact pressure portion that contacts the inner wall of the press-fitting hole and applies pressure to the inner wall;
A low contact pressure portion provided at a position different from the high contact pressure portion in the circumferential direction of the outer peripheral surface, and having a lower pressure applied to the inner wall of the press-fitting hole than the high contact pressure portion,
An inlay in which an incision having a predetermined depth is provided from the outer peripheral surface to cause an elastic repulsion force by elastic contraction upon press-fitting into the press-fitting hole . The press-fitting hole is circular,
The inlay according to claim 5 , wherein the low contact pressure portion has a smaller diameter from the axial center than the high contact pressure portion .

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