JP2018107326A - Circuit structure and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit structure capable of preventing short circuit between bus bars while realizing narrow pitch between bus bars.SOLUTION: In a circuit structure (1) including a bus bar group (31) where multiple bus bars (31A-31C) are arranged side by side, a circuit board (20) superposed on the bus bar group (31), and an electronic component (50) to be connected between the multiple bus bars (31A, 31B) and across the circuit board (20), the bus bar group (31) is provided with multiple protrusions (32A, 32B) protruding up to substantially the same height as a connection surface (20A) for connecting the electronic component (50) on the circuit board (20), the electronic component (50) is connected with the multiple protrusions (32A, 32B) and the circuit board (20), the bus bars (31A-31C) and the circuit board (20) are hardened each other with resin (40, 40A, 40B).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit structure and a manufacturing method thereof.

  2. Description of the Related Art Conventionally, a circuit structure in which electronic components such as a circuit board and a switching element (for example, an FET) are mounted on a bus bar is known. Specifically, a plurality of flat-shaped bus bars are arranged on the same plane, and one circuit board is fixed by an insulating adhesive material while leaving an exposed surface on one side of each. Of the electronic components, the main body is fixed to the exposed surface of the first bus bar, the drain terminal is also connected to the first bus bar, the source terminal is connected to the exposed surface of the second bus bar, and the gate terminal is a circuit. Each is connected to a conductive pattern formed on the substrate. That is, the switching element is connected across the two bus bars and is connected across the second bus bar and the circuit board.

  In such a circuit structure, since the height position of the second bus bar and the height position of the conductive pattern on the circuit board are inevitably different, the connection operation of each terminal is performed so as to straddle this. For example, it is difficult to cause a bonding failure by shifting the position of the other terminal while the connection work is being performed on one terminal.

  Therefore, for example, in Patent Document 1, the difference from the height position of the conductive pattern is eliminated by providing a projecting portion on the second bus bar to be a connection portion of the source terminal.

JP 2006-5096 A (page 4-5, FIG. 4)

  However, in recent years, with the miniaturization of switching elements, the source terminals tend to be shortened, and it has become difficult to straddle between two bus bars. In order to cope with this, it is conceivable to reduce the arrangement interval of the bus bars (that is, to reduce the span width between the bus bars of the source terminals). However, in this case, there is a possibility that the bus bars come into contact with each other due to vibration during use of the circuit structure, causing a short circuit.

  Therefore, in order to cope with the downsizing of electronic components, there has been a problem of how to prevent a short circuit between bus bars while realizing a narrow pitch between bus bars.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a circuit structure that can reliably insulate between bus bars while corresponding to downsizing of electronic components.

  The present invention includes a bus bar group in which a plurality of bus bars are arranged side by side, a circuit board arranged so as to overlap the bus bar group, and an electronic component connected between the plurality of bus bars and across the circuit board. In the circuit structure provided, the bus bar group is provided with a plurality of protrusions that protrude to substantially the same height as a connection surface that connects the electronic components of the circuit board, and the electronic components include the plurality of protrusions and Connected to the circuit board, the bus bars and the circuit board are fixed to each other by a resin.

  According to this configuration, the circuit board, which is the connection destination of the terminals of the electronic component, and the plurality of protrusions of the plurality of bus bars are arranged at substantially the same height, so that the connection work becomes easy and connection defects are reduced. can do. In addition, since the bus bars are insulated from each other by the resin, the interval between the plurality of bus bars can be reduced, and the terminal of the electronic component can be shortened.

  As an embodiment according to the terminal fitting of the present invention, the following configuration is preferable.

  The bus bar group is provided with the plurality of protrusions side by side, and the resin is filled between the plurality of protrusions.

  According to this configuration, since the resin is interposed between the plurality of protrusions, the bus bars can be more reliably insulated.

  A circuit configuration comprising a bus bar group in which a plurality of bus bars are arranged side by side, a circuit board arranged to overlap the bus bar group, and an electronic component connected between the plurality of bus bars and across the circuit board Forming a bus bar group having a plurality of protrusions protruding to substantially the same height as a connection surface connecting the electronic components of the circuit board; and the protrusions of the circuit board A step of arranging the circuit board on the bus bar group so as to be exposed at substantially the same height as a surface to which the electronic component is connected, and an inner surface of the molding die being in contact with the protrusion and the circuit board. And a step of integrating the bus bar group and the circuit board with resin by performing insert molding.

  According to this configuration, the bus bar and the circuit board can be integrated by insert molding, and the gap between the bus bars can be filled with the resin, so that an adhesive layer between the bus bar and the circuit board is not necessary, and between the two members. Can be reliably insulated.

  ADVANTAGE OF THE INVENTION According to this invention, the circuit structure body which can be insulated reliably between bus bars can be provided, respond | corresponding to size reduction of an electronic component.

A perspective view showing a circuit composition object of an embodiment A perspective view showing a circuit board The perspective view which shows a metal plate provided with a bus-bar group. Perspective view showing electronic components The perspective view which shows the state which aligned the circuit board on the metal plate FIG. 7 is a cross-sectional view taken along line AA in FIG. 7 showing a state in which the resin is filled in the mold. Perspective view showing circuit board and metal plate taken out from mold

<Embodiment>
An embodiment of the present invention will be described with reference to FIGS.

  1 in the present embodiment is connected between a power source (not shown) such as a battery and in-vehicle electrical components (not shown) such as a headlamp and a wiper, and various in-vehicle electrical components. Power supply and control of the power supply. In the following description, the Y direction in FIG. 1 is the front, the X direction is the left, and the Z direction is the upper.

  As shown in FIG. 1, the circuit structure 1 is configured by mounting an electronic component 50 on a circuit board 20 and a bus bar group 31 that are integrally molded with an insulating resin 40.

  The circuit structure 1 has a flat rectangular shape surrounded by a resin frame 40A, and the bus bar group 31 protrudes from the front edge. The upper surface of the main body 51 is a flat surface, and the upper surface of the circuit board 20 is exposed, and the upper surface of the first protrusion 32A and the upper surface of the second protrusion 32B are exposed. The first protrusion 32A and the second protrusion 32B are formed by projecting the first bus bar 31A and the second bus bar 31B upward, respectively, and are fitted into an escape hole 21 provided through the circuit board 20. Are arranged. The gaps between the first protrusion 32A, the second protrusion 32B, and the escape hole 21 are filled with resin 40B.

  The electronic component 50 is disposed on the first protrusion 32A, and three types of terminals are respectively connected to the first protrusion 32A, the second protrusion 32B, and the terminal connection portion 22 exposed on the upper surface of the circuit board 20. It is connected.

  As shown in FIG. 2, the circuit board 20 has a substantially rectangular plate shape as a whole, and the upper surface is a connection surface 20A on which a large number of conductive patterns (not shown) are formed according to the control circuit. Although the upper surface height of the conductive pattern and the height of the substrate surface are strictly different, the difference does not affect the manufacturing process of the circuit structure 1 in the present embodiment. Will be described.

  An escape hole portion 21 is provided in the region near the rear portion of the connection surface 20A of the circuit board 20 so as to penetrate vertically. The escape hole 21 has a shape in which a relatively large substantially rectangular rear hole 21A and a relatively small substantially rectangular front hole 21B are connected in the front-rear direction. The terminal connection portion 22 is provided along the front edge of the opening of the rear hole 21A, and is connected to the conductive pattern.

  In addition, resin filling holes 23 are vertically provided in two corners of the circuit board 20 on the diagonal line.

  Further, in a state before the manufacturing process of the circuit structure 1, a belt-like support portion 24 extending in the front-rear direction is provided continuously with a part of the left and right edge portions of the circuit board 20. In a portion where the circuit board 20 and the support portion 24 are continuous, a separation groove portion 25 is provided along the front-rear direction. Each support portion 24 is provided with an alignment hole 26 at a position shifted from each other in the front-rear direction.

  As shown in FIG. 3, the bus bar group 31 includes a plurality of bus bars 31 </ b> A to 31 </ b> C, and leaves the four sides of one metal plate 30 as the support frame 33, while leaving the inside of the metal plate 30 in a predetermined shape. . In the state before the manufacture of the circuit structure 1, the bus bar group 31 is arranged such that the bus bars 31 </ b> A to 31 </ b> C are arranged side by side with a gap between them inside the support frame 33 and are connected to the support frame 33 via the connecting portion 34. As a whole, the shape of one metal plate 30 is maintained. Note that support frame holes 35 are provided in the left and right frame portions of the support frame 33 (positions corresponding to the alignment holes 26 of the circuit board 20).

  The first bus bar 31A in the bus bar group 31 has a T-shape that extends along the front-rear direction and has a rear end portion that extends relatively wide left and right. And the part extended to the right and left protrudes upwards so that it may become one step higher than the plate | board surface of the metal plate 30, and becomes the above-mentioned 1st protrusion 32A. The protrusion height of the first protrusion 32 </ b> A is about the thickness of the circuit board 20.

  Further, the second bus bar 31B is disposed on the front side of each first protrusion 32A while providing a gap in a top view so that the right region of the rear end portion is one step higher than the plate surface of the metal plate 30. It protrudes upward and becomes the above-mentioned second protrusion 32B. The protrusion height of the second protrusion 32 </ b> B is about the thickness of the circuit board 20.

  In the support frame 33 of the metal plate 30, a plurality of control power bus bars 31 </ b> C for supplying power to the circuit board 20 are arranged with gaps therebetween. The first bus bar 31A, each second bus bar 31B, and each control power bus bar 31C extend forward, and the front end portion is a male terminal portion 38, respectively. Resin communication holes 39 are provided in the reinforcing plate portion.

  The electronic component 50 of this embodiment is a semiconductor switching element. As shown in FIG. 4, a substantially rectangular parallelepiped main body 51, a drain terminal 52 protruding from or extending from the main body, a source terminal 53, and a gate terminal 54, It has. The bottom surface of the tip of each terminal is aligned on the same plane as the bottom surface of the main body 51 so that when the electronic component 50 is placed on a flat surface, it naturally comes into contact with the surface of each placement destination. It has become. The drain terminal 52 also serves as a fixing member for fixing the electronic component 50 to the conductor to be connected.

  Next, the manufacturing method of the circuit structure 1 according to the present embodiment will be described with reference to FIGS.

  First, the circuit board 20 is overlaid on the metal plate 30 configured to support the bus bar group 31 on the support frame 33 as described above. The first protrusion 32A and the second protrusion 32B are fitted into the rear hole 21A and the front hole 21B of the circuit board 20, respectively, and the support frame hole 35 provided in the support frame 33 of the metal plate 30 is inserted into the circuit board 20. Is aligned with the alignment hole 26 (FIG. 5).

  Then, as shown in FIG. 6, the circuit board 20 and the metal plate 30 aligned with each other are set between an upper mold 61 and a lower mold 62 of a mold 60 attached to a resin 40 molding machine (not shown). Perform injection molding. In addition, the inner surface 61A of the upper mold 61 of the mold 60 is a flat surface without unevenness.

  In injection molding, polyphenylene sulfide (PPS) resin 40 is injected. Then, the injected PPS resin 40 passes through a path (not shown) to fill the gap between the circuit board 20 and the bus bar group 31 and the cavity defined by the mold 60 around them, and The resin filling hole 23 and the resin communication hole 39 of the metal plate 30 (reinforcing plate) are filled.

  The PPS resin 40 also flows into the escape hole 21 of the circuit board 20 and fills the gap between the first protrusion 32A and the second protrusion 32B fitted therein, and the first protrusion 32A and The gap between the second protrusion 32B and the escape hole 21 is filled. At this time, the flat inner surface 61A of the upper mold 61 is pressed against the upper surface of the first protrusion 32A, the upper surface of the second protrusion 32B, and the upper surface of the circuit board 20 at substantially the same height. The PPS resin 40 is also filled to the same height as the upper surface of the first protrusion 32A, the upper surface of the second protrusion 32B, and the upper surface of the circuit board 20.

  Then, after the PPS resin 40 is cured, the circuit board 20 and the metal plate 30 which are solidified by the resin 40 and integrated as shown in FIG. 7 are removed from the mold 60, and the support frame 33 and the connecting portion of the metal plate 30 are removed. 34 and the support part 24 of the circuit board 20 are cut off. Thereby, an integrally molded product of the circuit board 20 and the bus bar group 31 is obtained.

  Then, the gate of the electronic component 50 is exposed to the terminal connection portion 22 exposed on the connection surface 20A of the circuit board 20 and the first protrusion 32A and the second protrusion 32B protruding to substantially the same height as the connection surface 20A. The terminal 54, the drain terminal 52, and the source terminal 53 are soldered. Thus, the electronic component 50 is connected across the first bus bar 31A, the second bus bar 31B, and the terminal connection portion 22, and the circuit structure 1 shown in FIG. 1 is completed.

  According to the circuit configuration body 1 of the present embodiment, since the bus bars 31 are filled with the resin 40 and are reliably insulated from each other, the arrangement interval of the bus bars 31 can be reduced.

  Further, since the connecting surface 20A of the substrate unit and the first protrusion 32A and the second protrusion 32B have substantially the same height, the inner surface 61A of the upper mold 61 in the mold 60 used for insert molding is a flat surface. It can be. Thereby, the manufacturing cost of the metal mold | die 60 can be reduced, and it can respond easily also to design changes, such as a mounting position change of the electronic component 50. FIG.

  In addition, the lower surface of each terminal of the electronic component 50 is aligned on the same plane as the main body 51, and the first protrusion 32A, the second protrusion 32B, and the circuit board 20 are connected to the terminals. Since the connecting portions are at the same height position, when the main body 51 of the electronic component 50 is placed on each connection destination when performing a mounting operation, each terminal naturally contacts each connection destination. Therefore, for example, the posture of the electronic component 50 is stabilized as compared with the case where each terminal is placed at a connection destination having a different height, the mounting operation is facilitated, and connection failure due to misalignment is less likely to occur.

<Modification>
The present invention is not limited to the embodiment described with reference to the above description and drawings, and for example, the following modifications are also included in the technical scope of the present invention.

  (1) In the above embodiment, the entire upper surface of the circuit structure 1 is a flat surface. However, the present invention is not limited to this. For example, the resin frame 40A is provided with a recess, or the first protrusion 32A and the second protrusion. The resin amount may be reduced by lowering the height of the surrounding resin 40 than 32B. The point is that the first and second protrusions 32A and 32B and the terminal connection part 22 are disposed at the same height position, and the bus bars are reliably insulated from each other.

  (2) In the above embodiment, the electronic component 50 is a switching element. However, the present invention is not limited to this, and a mechanical relay or IGBT may be used. For example, when a mechanical relay is used, for example, the main body 51 may be arranged so as to straddle two bus bars.

  (3) In the above embodiment, the substrate unit is molded by injection molding in which the resin 40 is injected into the mold 60, and the PPS resin 40 is used as the resin 40 to be injected at that time. Not limited to. For example, other thermosetting resins or other thermoplastic resins may be employed, and transfer molding or the like may be employed. In short, it is only necessary to insulate the bus bars (projections) while integrating the circuit board 20 and the bus bar group 31.

DESCRIPTION OF SYMBOLS 1 Circuit structure 20 Circuit board 20A Connection surface 21 Escape hole part 22 Terminal connection part 24 Support part 30 Metal plate 31A First bus bar 31B Second bus bar 32A First protrusion 32A Second protrusion 40 Resin 50 Electronic component 52 Drain terminal 53 Source terminal 54 Gate terminal 60 Mold 61A Inner surface

Claims (3)

A circuit configuration comprising a bus bar group in which a plurality of bus bars are arranged side by side, a circuit board arranged to overlap the bus bar group, and an electronic component connected between the plurality of bus bars and across the circuit board In the body,
The bus bar group is provided with a plurality of protrusions that protrude to substantially the same height as a connection surface that connects the electronic components of the circuit board, and the electronic components are connected to the plurality of protrusions and the circuit board, A circuit structure in which the bus bars and the circuit board are fixed to each other by a resin.   The circuit structure according to claim 1, wherein the plurality of protrusions are provided side by side in the bus bar group, and the resin is filled between the plurality of protrusions. A circuit configuration comprising a bus bar group in which a plurality of bus bars are arranged side by side, a circuit board arranged to overlap the bus bar group, and an electronic component connected between the plurality of bus bars and across the circuit board A method for manufacturing a body,
Forming a bus bar group having a plurality of protrusions protruding to substantially the same height as a connection surface connecting the electronic components of the circuit board;
Disposing the circuit board on the bus bar group so that the protrusion is exposed at substantially the same height as a surface of the circuit board to which the electronic component is connected;
A step of integrating the bus bar group and the circuit board with a resin by performing insert molding so that the inner surface of the molding die is in contact with the protrusion and the circuit board;
A method for manufacturing a circuit structure comprising:

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