JP6136945B2 - Switching board - Google Patents

Description

  The present invention relates to a switching substrate.

  In recent years, automobiles equipped with an auxiliary power source in addition to a main battery have been developed in order to improve fuel economy and consider the environment. For example, regenerative energy at the time of braking is stored in an auxiliary power source and used for power supply to electrical components during traveling, thereby reducing the amount of power generated by the alternator and improving fuel efficiency. Further, when the engine is restarted after the idling stop, power is supplied to the starter from the auxiliary power source, so that the electrical components can be prevented from being momentarily interrupted or the main battery can be deteriorated due to the instantaneous drop in the voltage of the main battery.

  A switching board having a function of switching the power supply form may be installed between the main battery and the auxiliary power source in accordance with the operation state of the vehicle such as traveling or idling stop. As a switching board, what is provided with a circuit composition object provided with a bus bar and a control circuit board, and a switching element carried in this circuit composition object is used (refer to patent documents 1).

  The switching element has a control terminal and a power terminal, and the power terminal is connected to the bus bar. The connection between the power terminal and the bus bar is generally performed by reflow soldering.

JP 2004-274967 A

  Here, for the purpose of reducing material costs and simplifying the process, instead of bonding the bus bar and the control circuit board using an adhesive layer, it is proposed to laminate them with an insulating sheet and fix them by screwing. ing.

  However, in the case of fixing by screwing, unlike the case of fixing by an adhesive layer, the bus bar and the control circuit board are not in close contact with each other. For this reason, during reflow soldering, the solder may melt and diffuse into the gap between the bus bar and the insulating sheet or the gap between the insulating sheet and the control circuit board. When such a situation occurs, the connection reliability between the switching element and the bus bar decreases.

  The present invention has been completed based on the above-described circumstances, and an object thereof is to provide a switching substrate capable of regulating the diffusion of solder during reflow soldering.

The switching board of the present invention includes a control circuit board, a non-adhesive insulating sheet stacked on one surface of the control circuit board, and a bus bar stacked on the surface of the insulating sheet opposite to the control circuit board. A control circuit board, a circuit structure including a screw for fixing the insulating sheet and the bus bar to each other, a switching element having a terminal and mounted on the circuit structure, the control circuit board comprising: A mounting window penetrating from the surface facing the insulating sheet to the opposite surface thereof, wherein the insulating sheet is disposed so as to overlap the mounting window and facing the control circuit board from the opposite surface A solder attachment region to which solder for soldering the terminal is attached, wherein the bus bar is disposed in a region exposed inside the mounting window and the insertion window. , And a regulation groove which is disposed around the solder attachment regions.

  According to said structure, by arrange | positioning a control groove | channel around the solder adhesion area | region, the solder adhesion area | region and the area | region outside it are parted. As a result, when reflow soldering is performed, the melted solder spreads outside the solder adhesion area and is prevented from diffusing into the gap between the bus bar and the insulating sheet or the gap between the insulating sheet and the control circuit board. .

  As embodiments of the present invention, the following embodiments are preferable.

  The bus bar may include a copper or copper alloy base material and a nickel plating layer disposed on the surface of the base material, and the base material may be exposed on the inner surface of the restriction groove.

  According to said structure, since the copper or copper alloy whose affinity with a solder is higher than nickel is exposed inside a control groove, the flow-out of a solder can be controlled effectively.

  The bus bar may be a member formed by performing nickel plating on the surface of a copper or copper alloy base material having a base groove at the arrangement position of the restriction groove.

  A method of forming a member having a groove by performing nickel plating on the surface of a substrate having a base groove is called post-plating, and a groove is formed by scraping a copper plate or a copper alloy plate that has been previously plated with nickel. In some cases, the cost can be reduced more than the manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the switching board which can control the spreading | diffusion of the solder in the case of reflow soldering can be provided.

The perspective view of the switching device of an embodiment The exploded perspective view of the switching device of an embodiment Top view of switching substrate of embodiment Enlarged view in circle R ₁ of FIG. Bottom view of switching substrate of embodiment Partial enlarged sectional view of the switching substrate of the embodiment Plan view of the bus bar of the embodiment The top view which shows a mode that the bus-bar and insulating sheet of embodiment were piled up Enlarged view in circle R ₂ of FIG. The top view of the circuit composition object of an embodiment Plan view in circle R ₃ of FIG. Sectional drawing which shows an example of the cross-sectional shape of a control groove Sectional drawing-1 which shows the other example of the cross-sectional shape of a control groove | channel Sectional drawing-2 which shows the other example of the cross-sectional shape of a control groove | channel Sectional drawing-3 which shows the other example of the cross-sectional shape of a control groove | channel

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

  The switching device 1 according to the present embodiment switches power supply from a main battery and an auxiliary battery to electrical components in a vehicle including a main battery and an auxiliary battery.

  As shown in FIG. 2, the switching device 1 includes a switching substrate 10, an upper case 90, a lower case 96, and stud bolts 110A and 110B.

  The switching substrate 10 includes a circuit configuration body 11 and six semiconductor switching elements 60A and 60B mounted on the circuit configuration body 11.

  The circuit structure 11 includes a control circuit board 20, an insulating sheet 70, three bus bars 30, 40 and 50, and an auxiliary plate 80.

  The control circuit board 20 is a printed board including a control circuit made of a conductive material on one surface of an insulating plate made of a glass base material or a glass nonwoven fabric base (see FIG. 7). A part of the control circuit is a land 21 for connection to semiconductor switching elements 60A and 60B (corresponding to switching elements).

  As shown in FIG. 10, the control circuit board 20 has six mounting windows 22 and 23 for mounting the semiconductor switching elements 60A and 60B. The mounting windows 22 and 23 are openings that penetrate from the surface on the control circuit board 20 where the control circuit is arranged to the opposite surface.

  Three of the six mounting windows 22 and 23 are the first mounting windows 22 and are arranged in a line. The remaining three mounting windows among the six mounting windows 22 and 23 are the second mounting windows 23 and are arranged in a line. As shown in FIG. 11, the first mounting window 22 has a large hole portion 22L having a rectangular hole edge and one side of the large hole portion 22L, and the hole edge has a shape slightly larger than that of the large hole portion 22L. And a small rectangular small hole portion 22S. The second mounting window 23 has the same shape as the first mounting window 22 and includes a large hole portion 23L and a small hole portion 23S.

  The control circuit board 20 has a plurality of first screw insertion holes 24 and a plurality of second screw insertion holes 25. Each of the plurality of first screw insertion holes 24 and second screw insertion holes 25 is a through-hole penetrating from one surface of the control circuit board 20 to the other surface.

  The insulating sheet 70 is a rectangular thin sheet made of an insulating material such as resin. As shown in FIGS. 2 and 6, the insulating sheet 70 is overlaid on the other surface of the control circuit board 20 (the surface opposite to the surface on which the control circuit is formed).

  As shown in FIG. 9, the insulating sheet 70 is a rectangular sheet and includes six insertion windows 71 and 72. Each insertion window 71, 72 is an opening that penetrates from the surface of the insulating sheet 70 on which the control circuit board 20 is disposed to the opposite surface.

  Each first insertion window 71 has the same hole edge shape as the hole edge shape of the first mounting window 22. That is, as shown in FIG. 10 and FIG. 11, each first insertion window 71 is connected to a large hole portion 71 </ b> L having a rectangular hole edge and one side of the large hole portion 71 </ b> L, and the hole edge shape is a large hole portion. It has a rectangular small hole 71S that is slightly smaller than 71L. Each of the three first insertion windows 71 overlaps with each of the three first mounting windows 22. Similarly, each second insertion window 72 has the same hole edge shape as that of the second mounting window 23, and includes a large hole portion 72L and a small hole portion 72S. Each of the three second insertion windows 72 is disposed so as to overlap with each of the three second mounting windows 23.

  The insulating sheet 70 has a plurality of first screw insertion holes 73 and a plurality of second screw insertion holes 74. Each of the plurality of first screw insertion holes 73 is disposed so as to overlap the first screw insertion hole 24 of the control circuit board 20. Each first screw insertion hole 73 is a through-hole penetrating from one surface of the insulating sheet 70 to the other surface. Each of the plurality of second screw insertion holes 74 overlaps with the second screw insertion hole 25 of the control circuit board 20. Each second screw insertion hole 74 is a through-hole penetrating from one surface of the insulating sheet 70 to the other surface.

  As shown in FIGS. 2 and 6, the three bus bars 30, 40, 50 are arranged side by side on the surface opposite to the surface on which the control circuit board 20 of the insulating sheet 70 is disposed. One of the three bus bars 30, 40, 50 is the input bus bar 30, and the other one is the output bus bar 40.

  As shown in FIG. 7, the input bus bar 30 is a rectangular thick plate made of a conductive material. The input bus bar 30 includes a bolt insertion hole 31. The bolt insertion hole 31 is a through-hole penetrating from one plate surface of the input bus bar 30 to the other plate surface.

  As shown in FIG. 7, the output bus bar 40 is a rectangular thick plate formed of a conductive material. The output bus bar 40 includes a bolt insertion hole 41. The bolt insertion hole 41 is a through-hole penetrating from one plate surface of the input bus bar 30 to the other plate surface.

  The input bus bar 30 and the output bus bar 40 are arranged in parallel with a space between each other. As shown in FIG. 10, the input bus bar 30 and the output bus bar 40 partially overlap the control circuit board 20, and the portions where the bolt insertion holes 31 and 41 are arranged are detached from the insulating sheet 70 and the control circuit board 20. Are arranged.

  The remaining one of the three bus bars 30, 40, 50 is a connection bus bar 50. As shown in FIG. 7, the connection bus bar 50 is a T-shaped thick plate made of a conductive material. The connection bus bar 50 includes a connection part 51 and a reinforcement part 52.

  The connecting portion 51 is an elongated rectangular plate that forms a T-shaped vertical plate portion. The connecting portion 51 is disposed between the input bus bar 30 and the output bus bar 40 with a gap from the input bus bar 30 and the output bus bar 40. The connecting portion 51 is arranged in parallel with the input bus bar 30 and the output bus bar 40.

  The reinforcing portion 52 is an elongated rectangular plate forming a T-shaped horizontal plate portion, and is disposed at one end of the connecting portion 51 and perpendicular to the connecting portion 51. The reinforcing portion 52 is disposed with a gap with respect to the input bus bar 30 and the output bus bar 40. The reinforcing part 52 extends along the direction in which the input bus bar 30, the connection part 51, and the output bus bar 40 are arranged.

  As shown in FIGS. 6, 8, and 10, each of the plurality of first mounting windows 22 and first insertion windows 71 is disposed at a position spanning the input bus bar 30 and the connecting portion 51, and has a large hole. The portions 22L and 71L overlap the input bus bar 30, and the small hole portions 22S and 71S overlap the connection portion 51. One side where the small hole portions 22S and 71S are continuous in the large hole portions 22L and 71L is arranged along the gap between the input bus bar 30 and the connection portion 51. A part of the input bus bar 30 is exposed inside the large hole parts 22L and 71L, and a part of the connection part 51 is exposed inside the small hole parts 22S and 71S.

  Each of the plurality of second mounting windows 23 and second insertion windows 72 is disposed at a position spanning the output bus bar 40 and the connection portion 51, the large hole portions 23L and 72L overlap the output bus bar 40, and the small hole portions 23S, 72S is arranged so as to overlap the connecting portion 51. One side where the small hole portions 23S and 72S are continuous in the large hole portions 23L and 72L is arranged along the gap between the input bus bar 30 and the connection portion 51. A part of the output bus bar 40 is exposed inside the large hole parts 23L and 72L, and a part of the connection part 51 is exposed inside the small hole parts 23S and 72S.

  As shown in FIG. 7, the input bus bar 30 includes a plurality of solder adhesion regions 32 and a plurality of first restriction grooves 33 (corresponding to restriction grooves). The solder adhesion region 32 is a region on which the solder S for connecting the semiconductor switching elements 60A and 60B is placed. The first restriction groove 33 is a groove for restricting the solder S from melting and diffusing outside the solder adhesion region 32. Each of the solder adhesion regions 32 and each of the first restriction grooves 33 is disposed in a region exposed to the inside of each large hole portion 22L in the input bus bar 30.

  The first restricting groove 33 is a groove extending along three sides of the hole edge of the large hole portion 22L except for one side where the small hole portions 22S are continuous. The solder adhesion region 32 is a region of the input bus bar 30 that is surrounded by the gap between the input bus bar 30 and the connection portion 51 and the first restriction groove 33.

  Similarly, the output bus bar 40 has a plurality of solder adhesion regions 42 and a plurality of second restriction grooves 43 (corresponding to restriction grooves). Each of the solder adhesion regions 42 and each of the second restriction grooves 43 is disposed in a region exposed to the inside of each large hole portion 23 </ b> L in the output bus bar 40. The second restricting groove 43 is a groove extending along three sides of the hole edge of the large hole portion 23L except for one side where the small hole portions 23S are continuous. In the output bus bar 40, the solder adhesion region 42 is a region surrounded by the gap between the output bus bar 40 and the connection portion 51 and the first restriction groove 33.

  Similarly, the connecting portion 51 has a plurality of solder adhesion regions 53 and a plurality of third restriction grooves 54 (corresponding to restriction grooves). Each solder adhesion region 53 and each third restriction groove 54 are disposed in a region exposed to the inside of each small hole 22S, 23S in the connection bus bar 50. The third restriction groove 54 disposed inside the small hole portion 22S is a groove extending along the hole edge (three sides excluding one side continuous with the large hole portion 22L) of the small hole portion 22S. The solder adhesion region 53 disposed inside the small hole portion 22 </ b> S is a region surrounded by the gap between the input bus bar 30 and the connection portion 51 and the third restriction groove 54 in the connection portion 51. The third restriction groove 54 disposed inside the small hole portion 23S is a groove extending along the hole edge (three sides excluding one side continuous with the large hole portion 23L) of the small hole portion 23S. The solder adhesion region 53 disposed inside the small hole portion 23 </ b> S is a region surrounded by the gap between the output bus bar 40 and the connection portion 51 and the third restriction groove 54 in the connection portion 51.

As shown in the example shown in FIG. 12, the input bus bar 30A includes a copper base material 36A and a nickel plating layer 37A disposed on the surface of the base material 36A, and the first restriction groove of the input bus bar 30A. 33A is a depth D _a of the groove defined by the distance to the bottom surface 38A of the first regulating groove 33A from arranged surface (the surface of the nickel plating layer 37A), and is smaller than the thickness of the nickel plating layer 37A Also good. Since the first restricting groove 33A having such a shape can be formed by etching a part of the nickel plating layer 37A by etching, there is an advantage that a large manufacturing facility is unnecessary and the manufacturing cost can be reduced.

Alternatively, as in the example shown in FIG. 13, the input bus bar 30B includes a copper base material 36B and a nickel plating layer 37B disposed on the surface of the base material 36B. the depth D _B of the groove which is defined by the distance from the surface restriction grooves 33B are disposed (the surface of the nickel plating layer 37B) to the bottom surface 38B of the first regulating groove 33B is not equal to the thickness of the nickel plated layer 37B May be. The first restriction groove 33B having such a shape can be formed by, for example, etching the nickel plating layer 37B to the surface of the base material 36B by etching. As for the 1st control groove | channel 33B, the base material 36B is exposed in the bottom face 38B (it corresponds to an inner surface).

Alternatively, as in the example shown in FIG. 14, the input bus bar 30 </ b> C includes a copper base material 36 </ b> C and a nickel plating layer 37 </ b> C disposed on the surface of the base material 36 </ b> C. the depth D _C of the groove defined by the distance from the surface of regulating groove 33C is disposed (the surface of the nickel plating layer 37C) to the bottom surface 38C of the first regulating groove 33C is larger than the thickness of the nickel plating layer 37C It may be. The first restriction groove 33C having such a shape is obtained by, for example, machining the bus bar 30C from the surface of the nickel plating layer 37C to a position slightly deeper than the boundary surface with the nickel plating layer 36C in the base material 37C. Can be formed. The first regulation groove 33C has a base material 36C exposed at the bottom surface 38C (corresponding to the inner surface).

  The first regulation grooves 33B and 33C having the shapes shown in FIGS. 13 and 14 have the bases 36B and 36C exposed at the bottom surfaces 38B and 38C. That is, the first restriction grooves 33B and 33C have an advantage that the flow of the solder S can be effectively restricted because copper having higher affinity with the solder S than nickel is exposed inside the groove.

  Alternatively, as in the example shown in FIG. 15, the input bus bar 30 </ b> D includes a copper base material 36 </ b> D and a nickel plating layer 37 </ b> D disposed on the surface of the base material 36 </ b> D, and the first restriction groove 33 </ b> D is formed. Alternatively, a groove in which a nickel plating layer 37D is disposed on the inner surface of a base groove 39 provided in the base material 36D may be used. The input bus bar 30 </ b> D having such a groove can be formed by performing nickel plating on the surface of the base material 36 </ b> D having the base groove 39. Such a manufacturing method is called post-plating, and the cost may be reduced as compared with a manufacturing method in which a copper plate on which nickel plating is applied is cut to form a groove.

  The same applies to the second restriction groove 43 and the third restriction groove 54.

  As shown in FIG. 7, the input bus bar 30 has a plurality of first screw insertion holes 34 and a plurality of second screw insertion holes 35. Each of the plurality of first screw insertion holes 34 is disposed so as to overlap the first screw insertion hole 24 of the control circuit board 20. Each first screw insertion hole 34 is a through-hole penetrating from one surface of the input bus bar 30 to the other surface. A part of the plurality of second screw insertion holes 35 is arranged so as to overlap the second screw insertion hole 25 of the control circuit board 20, and the other second screw insertion holes 35 are arranged from the control circuit board 20. It is placed at a position that is off. Each second screw insertion hole 35 is a through-hole penetrating from one surface of the input bus bar 30 to the other surface.

  The output bus bar 40 has a plurality of first screw insertion holes 44 and a plurality of second screw insertion holes 45. Each of the plurality of first screw insertion holes 44 is disposed so as to overlap the first screw insertion hole 24 of the control circuit board 20. Each first screw insertion hole 44 is a through-hole penetrating from one surface of the output bus bar 40 to the other surface. Some of the plurality of second screw insertion holes 45 are arranged so as to overlap the second screw insertion holes 25 of the control circuit board 20, and the other second screw insertion holes 45 extend from the control circuit board 20. It is placed at a position that is off. Each second screw insertion hole 45 is a through-hole penetrating from one surface of the output bus bar 40 to the other surface.

  The connection bus bar 50 has a plurality of first screw insertion holes 55. Each of the plurality of first screw insertion holes 55 is disposed so as to overlap the first screw insertion hole 24 of the control circuit board 20. Each first screw insertion hole 55 is a through-hole penetrating from one surface of the input bus bar 30 to the other surface.

  The auxiliary plate 80 is a rectangular plate made of an insulating material such as resin. As shown in FIGS. 2 and 6, the auxiliary plate 80 is disposed on the surface opposite to the surface on which the insulating sheets 70 of the bus bars 30, 40, 50 are disposed.

  The auxiliary plate 80 has a plurality of first screw holes 81 and a plurality of second screw insertion holes 82. Each of the plurality of first screw holes 81 is disposed so as to overlap the first screw insertion hole 24 of the control circuit board 20. Each first screw hole 81 is a bottomed hole in which a screw is cut on the inner peripheral surface. The plurality of second screw insertion holes 82 are disposed so as to overlap the second screw insertion holes 25 of the control circuit board 20. Each second screw insertion hole 82 is a through-hole penetrating from one surface of the auxiliary plate 80 to the other surface.

  The semiconductor switching elements 60A and 60B are power MOSFETs and include a housing 61, a drain terminal 62 (corresponding to a terminal), a source terminal 63 (corresponding to a terminal), and a gate terminal 64 provided in the housing 61. . The drain terminal 62 is disposed on the lower surface of the housing 61 as shown in FIG. Moreover, the source terminal 63 and the gate terminal 64 protrude from the side surface of the housing 61 as shown in FIG.

  As shown in FIG. 3, three of the six semiconductor switching elements 60A and 60B are first semiconductor switching elements 60A. The remaining three of the six semiconductor switching elements 60A and 60B are second semiconductor switching elements 60B.

  The three first semiconductor switching elements 60 </ b> A are disposed inside the first mounting window 22 and the first insertion window 71, respectively. The drain terminal 62 is connected to the solder adhesion region 32 of the input bus bar 30, and the source terminal 63 is connected to the solder adhesion region 53 of the connection portion 51. The gate terminal 64 is connected to the land 21.

  Similarly, the three second semiconductor switching elements 60B are disposed inside the second mounting window 23 and the second insertion window 72, respectively. The drain terminal 62 is connected to the solder attachment region 42 of the output bus bar 40, the source terminal 63 is connected to the solder attachment region 53 of the connection portion 51, and the gate terminal 64 is connected to the land 21. The connection is made by soldering.

  By arranging in this way, three semiconductor switching elements 60A and 60B connected in parallel form one set, and two sets of semiconductor switching elements 60A and 60B are connected in series. The two sets of semiconductor switching elements 60A and 60B are arranged back to back.

As shown in FIGS. 1 and 2, the stud bolt 110 </ b> A is a member for fixing the fastening terminal 101 </ b> A connected to one end of the wire harness 100 </ b> A connected to the main battery to the input bus bar 30.
The stud bolt 110B is a member for fixing the fastening terminal 101B connected to one end of the wire harness 100B connected to the auxiliary battery to the output bus bar 40.

  The stud bolt 110A has a shaft portion 112A that is threaded on the outer peripheral surface of a metal round bar, and a prismatic head portion 111A that is disposed at one end of the shaft portion 112A. Similarly, the stud bolt 110B includes a shaft portion 112B and a head portion 111B.

  The upper case 90 is made of synthetic resin and covers the surface on which the auxiliary plate 80 of the switching substrate 10 is disposed. As shown in FIG. 2, the upper case 90 is a tray-like case having an outer shape that is slightly larger than the outer shape of the switching substrate 10, and includes a rectangular top plate 91 arranged in parallel with the switching substrate 10, And a side plate 92 extending from the periphery of the top plate 91 toward the switching substrate 10.

  The upper case 90 includes an accommodation recess 93 for accommodating the auxiliary plate 80 therein, a plurality of screw holes 94, and two fastening windows 95A and 96B.

  The housing recess 93 is a recess that is recessed in a direction away from the switching substrate 10 from the surface facing the switching substrate 10 of the upper case 90, and has an outer shape that is slightly larger than the outer shape of the auxiliary plate 80.

  A part of the plurality of screw holes 94 is disposed so as to overlap the first screw insertion hole 24 of the control circuit board 20. The other part of the plurality of screw holes 94 is disposed so as to overlap the second screw insertion hole 35 of the input bus bar 30 or the second screw insertion hole 45 of the output bus bar 40.

  One fastening window 95A of the two fastening windows 95A and 96B is disposed at and around the position where the bolt insertion hole 31 is disposed. Similarly, the other fastening window 95B is disposed at and around the position where the bolt insertion hole 31 is disposed. Each fastening window 95A, 95B is an opening that penetrates from one surface of the top plate 91 to the other surface.

  The lower case 96 is made of synthetic resin and covers the surface of the switching board 10 on which the control circuit board 20 is disposed. As shown in FIG. 2, the lower case 96 is a thick plate having substantially the same outer shape as the upper case 90 and is arranged in parallel with the switching substrate 10.

  The procedure for assembling the switching device 1 configured as described above will be described below.

First, the switching substrate 10 is assembled.
First, the circuit structure 11 is assembled. The control circuit board 20, the insulating sheet 70, the three bus bars 30, 40, 50, and the auxiliary plate 80 are stacked in this order. Then, by inserting the first screw 120 (corresponding to the screw) through the first screw insertion holes 24, 34, 46, 73 and screwing it into the first screw hole 81, the control circuit board 20, the insulating sheet 70, The three bus bars 30, 40, 50 and the auxiliary plate 80 are fixed to each other.

Next, the semiconductor switching elements 60 </ b> A and 60 </ b> B are mounted on the circuit structure 11.
Solder S is applied to each of the plurality of solder adhesion regions 32, 42, 53 and the plurality of lands 21 by, for example, screen printing. Next, each of the plurality of semiconductor switching elements 60 </ b> A is aligned and disposed inside the first mounting window 22 and the first insertion window 71. That is, the semiconductor switching element 60A has a drain terminal 62 on the solder adhesion region 32 in the large hole portion 22L, a source terminal 63 on the solder adhesion region 53 in the small hole portion 22S, and the land 21 on the control circuit board 20. The gate terminal 64 is aligned on the circuit structure 11 and placed on the circuit structure 11. Similarly, each of the plurality of semiconductor switching elements 60 </ b> B is aligned and disposed inside the second mounting window 23 and the second insertion window 72.

  Next, the circuit structure 11 is installed in a reflow furnace (not shown), heated to the solder melting temperature, and then cooled to solder each terminal 62, 63, 64.

  Next, the upper case 90 and the lower case 96 are assembled to the switching substrate 10.

  First, the upper case 90 is overlaid on the switching substrate 10. Then, the switching board 10 is fixed to the upper case 90 by inserting the second screw 121 through the second screw insertion holes 25, 35, 47, 57, 74 and 82 and screwing the second screw 121 into the screw hole 94. In the switching board 10, the peripheral portion of the portion where the bolt insertion hole 31 is arranged in the input bus bar 30 is exposed inside the fastening window 95 </ b> A, and the peripheral portion of the portion where the bolt insertion hole 41 is arranged in the output bus bar 40 is the fastening window. Arranged in an exposed state inside 95B.

  Next, the shaft portion 112A of the stud bolt 110A is inserted through the bolt insertion hole 31, and the shaft portion 112B of the stud bolt 110B is inserted through the bolt insertion hole 41. The shaft portion 112A is disposed inside the fastening window 95A, and the shaft portion 112B is disposed inside the fastening window 95B.

  Next, the lower case 96 is overlaid on the switching substrate 10 and assembled to the upper case 90.

  A fastening terminal 101A connected to the wire harness 100A connected to the main battery is fixed to the input bus bar 30 by a stud bolt 110A and a nut 113A fastened to the tip of the stud bolt 110A. Further, a fastening terminal 101B connected to the wire harness 100B connected to the auxiliary battery is fixed to the output bus bar 40 by a stud bolt 110B and a nut 113B fastened to the tip of the stud bolt 110B.

(Effect of this embodiment)
According to this embodiment, the first restriction groove 33, the second restriction groove 43, or the third restriction groove 54 is disposed around each of the plurality of solder attachment regions 32, 42, 53, so that the solder attachment is achieved. The areas 32, 42, and 53 are separated from the outer area. Thus, during reflow soldering, the melted solder S wets and spreads outward from the solder adhesion regions 32, 42, 53, and the gap between the bus bars 30, 40, 50 and the insulating sheet 70, or the insulating sheet 70 and the control circuit. Diffusion in the gap with the substrate 20 is restricted.

<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 above embodiment, the input bus bar 30 has the copper base material 36 and the nickel plating layer 37 disposed on the surface of the base material 36, but the base material is copper alloy. Also good. Alternatively, the bus bar may be an unplated copper plate or copper alloy plate.

(2) In the above embodiment, the first restriction groove 33 is a groove extending along three sides of the hole edge of the large hole portion 22L except for one side where the small hole portion 22S is continuous. The adhesion region may be disposed so as to surround the entire circumference, or may be disposed only at a part of the outer edge of the solder adhesion region.

DESCRIPTION OF SYMBOLS 10 ... Switching board 11 ... Circuit structure 20 ... Control circuit board 22 ... 1st mounting window (mounting window)
23. Second mounting window (mounting window)
30, 30A, 30B, 30C, 30D ... Input bus bar (bus bar)
32, 42, 53 ... solder adhesion region 33 ... first restriction groove (regulation groove)
36A, 36B, 36C, 36D ... base materials 37A, 37B, 37C, 37D ... nickel plating layers 38B, 38C ... bottom surface (inner surface)
39 ... Base groove 40 ... Output bus bar (bus bar)
43 ... Second restriction groove (regulation groove)
50 ... Connection bus bar (bus bar)
54 ... Third restriction groove (regulation groove)
60A ... Semiconductor switching element (switching element)
60B ... Semiconductor switching element (switching element)
62 ... Drain terminal (terminal)
63 ... Source terminal (terminal)
70 ... Insulating sheet 71 ... First insertion window (insertion window)
72. Second insertion window (insertion window)
120 ... 1st screw (screw)
S ... Solder

Claims (4)

A control circuit board; a non-adhesive insulating sheet superimposed on one surface of the control circuit board; a bus bar superimposed on a surface of the insulating sheet opposite to the control circuit board; the control circuit board; A circuit structure comprising an insulating sheet and a screw for fixing the bus bar to each other;
A switching element that has a terminal and is mounted on the circuit structure,
The control circuit board includes a mounting window penetrating from the surface facing the insulating sheet to the opposite surface thereof,
The insulating sheet is disposed so as to overlap the mounting window, and includes an insertion window that penetrates from the surface facing the control circuit board to the opposite surface thereof,
The bus bar is disposed in an area exposed inside the mounting window and the insertion window, and is disposed around a solder adhesion area to which solder for soldering the terminals adheres, and around the solder adhesion area. A switching substrate comprising a regulation groove. 2. The switching substrate according to claim 1, wherein the restriction groove is disposed over the entire length of a portion adjacent to a hole edge of the mounting window and the insertion window around the solder adhesion region. The bus bar has a copper or copper alloy base material, and a nickel plating layer disposed on the surface of the base material,
The switching substrate according to claim 1, wherein the base material is exposed on an inner surface of the restriction groove.   The switching according to claim 1 or 2, wherein the bus bar is a member formed by performing nickel plating on a surface of a copper or copper alloy base material having a base groove at an arrangement position of the restriction groove. substrate.

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