JP4765849B2 - Circuit material and in-vehicle electrical junction box containing the circuit material - Google Patents

Description

  The present invention relates to a circuit material accommodated in an electrical junction box and an on-vehicle electrical junction box that accommodates the circuit material, and uses a multilayer printed board as an internal circuit material of an on-vehicle electrical junction box such as a junction box, and copper foil of each layer The pattern is made conductive and the allowable current amount is partially increased.

  In an in-vehicle electrical junction box, a printed board printed with a copper foil pattern having a thickness of 105 μm is usually used as a printed board housed in a main power distribution box such as a junction box. Since the allowable current value per 1 mm of circuit width of the copper foil pattern is 6A, when a large current is applied to the copper foil pattern, the allowable current amount can be increased by increasing the width or thickness of the copper foil pattern. Need to increase.

However, when the width of the circuit pattern is increased, there is a problem that the density of the circuit is lowered and the entire printed circuit board is enlarged. Further, if the thickness of the copper foil pattern is thicker than 105 μm, the cost in the etching process increases, which is not realistic. In addition, when the allowable current value is significantly increased partially, the allowable current value cannot be significantly increased even if the width of the copper foil pattern is increased.
Therefore, it is desired to increase the allowable current value per 1 mm of the circuit width of the copper foil pattern and reduce the circuit wiring density without reducing the circuit wiring density.

For example, in Japanese Patent Laid-Open No. 2000-332419 (Patent Document 1), there is provided a multilayer printed circuit board 1 in which a plurality of printed circuit boards 2 shown in FIG. Interlayer connection is made through the material 4.
When such a circuit for connecting the layers of the multilayer printed circuit board 1 is a power circuit, the copper foil pattern connected to the electric wire is a power supply upstream circuit, and the copper foil pattern of the printed circuit board connected to other layers is a branch connection circuit. It becomes.
In that case, it is necessary to increase the energization amount of the circuit on the upstream side of the power source. However, if the width of the copper foil pattern is increased as described above, the wiring density of the circuit is lowered and the entire printed circuit board is enlarged. Arise.

JP 2000-332419 A

  The present invention is a circuit in which an allowable current amount is increased without increasing the width of a copper foil pattern serving as an upstream circuit in which copper foil patterns of different layers are interlayer-connected among copper foil patterns of a multilayer printed board. The issue is to provide materials.

In order to solve the above problems, a circuit material accommodated in an on-vehicle electrical junction box,
A through hole for connecting the copper foil pattern of the multilayer printed board to the interlayer is provided, and a bus bar is disposed on at least a part of the surface of the copper foil pattern of the outermost layer of the multilayer printed board, and a part of the bus bar is the through hole. Located on the opening surface of
The bus bar and the multilayer printed circuit board are fixed to each other with solder filling the through hole, and the bus bar and the copper foil pattern on the inner and outer layers of the multilayer printed circuit board are electrically connected , and the bus bar is divided into bus bars. The divided bus bars are arranged on copper foil patterns of different circuits on the surface of the multilayer printed circuit board and connected to each other, and terminals are projected from the divided ends of the divided bus bars, and jumpers are connected between the terminals. Connect, and
Wherein between the jumper wire and the multilayer printed circuit board surface and provides a circuit material for accommodating the electrical connection box are arranged another bus bar or wire.

According to the circuit material of the present invention, the bus bar can be fixed to the surface of the multilayer printed board by the solder filled in the through hole, and the outermost copper foil pattern and the copper foil pattern of each layer are electrically connected to the bus bar. The bus bar that is conductive to the copper foil pattern can pass a larger current than the copper foil pattern. Since the portion requiring a large current is configured by the bus bar in this way, it is not necessary to increase the width of the copper foil pattern, and the wiring density of the circuit may be reduced and the entire multilayer printed board may be enlarged. Absent.
In particular, when the copper foil pattern of the multilayer printed circuit board connected to the bus bar is a power circuit, the multilayer printed circuit board is interlayer-connected from the power upstream circuit where the copper foil pattern on the surface and the bus bar are superposed to increase the allowable energization value. The copper foil pattern can be energized.
Moreover, heat dissipation can also be improved by arrange | positioning the bus-bar on the surface of a multilayer printed circuit board.

Specifically, one end opening of the through hole is closed by the bus bar, and solder filled from the other end opening of the through hole is fixed to the closing portion of the bus bar.
According to the above configuration, since the through hole can be filled with solder without any gap, the copper foil pattern of each layer and the bus bar can be reliably electrically connected by the solder, and the electrical connection reliability can be further improved. .

Alternatively, the bus bar is provided with a through hole communicating with one end opening of the through hole provided in the multilayer printed board, and the conductive metal pin is penetrated through the communicated through hole, and the inner periphery of the conductive metal pin and the through hole is provided. The conductive metal pins, the bus bars, and the copper foil patterns of the respective layers are connected through solder filling the surface.
According to the said structure, a multilayer printed circuit board and a bus-bar can be positioned with the conductive metal pin penetrated to the through-hole of a multilayer printed circuit board, and the through-hole of a bus bar, and the filling operation | work of solder can be made easier. .

One bus bar may be arranged and fixed on a copper foil pattern of a different circuit on the surface of the multilayer printed board, and the circuit of the copper foil pattern may be connected by the bus bar.
According to the said structure, the circuit can be formed via a bus bar, Therefore The freedom degree of the circuit design of a multilayer printed circuit board can be raised. Further, by changing the arrangement position and shape of the bus bar that is electrically connected to the copper foil pattern of the multilayer printed board, it is possible to flexibly cope with the circuit change without changing the copper foil pattern.

As before reporting, it constitutes a bus bar from the divided bus bar, and placing the divided bus bar on a copper foil pattern of the different circuits of the surface of the multilayer printed circuit board and respectively connected, butt terminals to split ends of the split bus bar Connect these terminals with jumper wires, and
Between the jumper wire and the multilayer printed circuit board surface, and place another bus bar or wire.
According to the said structure, a circuit can be crossed and provided on the same surface of a multilayer printed circuit board, and a circuit density can be raised.

  The solder is preferably lead-free solder having high thermal conductivity. In addition to the solder, it is possible to use a copper-containing paste or a conductive adhesive, but solder is preferable in terms of thermal conductivity.

In the present invention, an on-vehicle electrical junction box such as a junction box containing the circuit material is provided.
In the electrical junction box containing the circuit material, a small current circuit such as a signal circuit can be provided with high density by a multilayer printed circuit board as compared with the case where the bus bar is a main circuit material, and a large current is generated by the bus bar. Since the circuit is also provided on the multilayer printed circuit board, the multilayer printed circuit board can be used as the main circuit material, and the circuit material can be simplified and miniaturized. As a result, the electrical junction box is reduced in size and weight. Can be

As described above, according to the present invention, the bus bar can be fixed to the surface of the multilayer printed board by the solder filled in the through hole provided in the multilayer printed board, and the copper foil pattern of each layer and the bus bar are made conductive. The bus bar that is conductive to the copper foil pattern can pass a larger current than the copper foil pattern. Since the portion requiring a large current is configured by the bus bar in this way, it is not necessary to increase the width of the copper foil pattern, and the wiring density of the circuit may be reduced and the entire multilayer printed board may be enlarged. Absent.
In particular, when the interlayer connection portion of the multilayer printed circuit board forms a branch portion of a power supply circuit, energization of a large current is required on the upstream side of the branch portion. Can consist of busbar.

Embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a reference to the first embodiment of the present invention, the circuit member 10 is intended to house the electrical connection box 20 for the vehicle, the electronic component P relays and fuses etc. on the surface of the circuit member 10 Is implemented.

As shown in FIG. 2, the multilayer printed circuit board 11 constituting the circuit material 10 has an insulating layer 13.
And copper foil patterns 14 are alternately laminated. In this embodiment, three insulating layers 13 are arranged between four copper foil patterns 14.
In addition, the number of layers of the copper foil pattern 14 is not limited to four, and may be three or more.

  A through hole is provided in the land portion of the copper foil pattern 14 and the insulating layer 13, and all the through holes are connected to form one through hole 16.

  The through-hole 16 is plated 17 so that the copper foil pattern 14 exposed on the inner peripheral surface of the through-hole 16 is electrically connected to the plating 17.

The one end opening on the lower end side in FIG. 2 of the through hole 16 is closed by a bus bar 18 that overlaps the lowermost copper foil pattern 14A. The bus bar 18 is made to conform to the shape of the copper foil pattern 14 continuing to the land portion where the through hole 16 is provided, and is equal to or smaller than the width of the copper foil pattern 14.
The through-hole 16 is filled with solder 19 from the front end opening, and the bus bar 18 is fixed to the multilayer printed board 11 with the solder 19, thereby fixing the bus bar 18 also to the copper foil pattern 14A.

The circuit material 10 is prepared in such a manner that plating 17 is applied to the through-holes 16 of the multilayer printed circuit board 11, the bus bars 18 are overlaid on the lowermost copper foil pattern 14, and the through-holes 16 are closed.
In this state, the through hole 16 is filled with the solder 19 from the tip opening.
The solder 19 is fixed to the closed portion 18 a facing the through hole 16 of the bus bar 18 and to the inner peripheral surface of the plated through hole 16.
Thereby, the bus bar 18 and the multilayer printed board 11 are fixed via the solder 19, and the bus bar 18 and the copper foil pattern 14 of each layer are electrically connected via the solder 19 and the plating 17.
The bus bar 18 and the lowermost copper foil pattern 14A may be fixed in advance with solder.

In this reference embodiment, the thickness of 105μm copper foil pattern 14, a width of 10 mm, a thickness of 0.64mm bus bar 18, the width 9 mm, per circuit width 1mm in part superimposed copper foil patterns 14A and the bus bar 18 The allowable current value is 20 A, and the allowable current value per 1 mm of the circuit width is 6 A in the portion of the copper foil pattern 14 alone.
The solder 19 is made of lead-free solder having a thermal conductivity of 66.6 W / m · K, and has a much higher thermal conductivity than an adhesive or the like.

In the circuit material 10 having the above-described configuration, the copper foil pattern 14 and the bus bar 18 of each layer can be electrically connected by the plating 17 of the through holes 16 provided in the multilayer printed board 11 and the solder 19 filled in the through holes 16. The bus bar 18 can partially form a large current circuit portion in the circuit material 10. Since the portion requiring the large current is configured by the bus bar 18 as described above, it is not necessary to increase the width of the copper foil pattern 14, the circuit wiring density is reduced, and the entire multilayer printed board 11 is enlarged. There is no end.
Further, a portion where the copper foil patterns 14 of each layer of the multilayer printed circuit board 11 are connected to each other serves as a branch portion of the circuit. Since the bus bar 18 is connected to the interlayer connecting portion via the solder 19 and the plating 17, The bus bar 18 can easily form the upstream side of the branch portion requiring current.
Furthermore, the heat dissipation can be enhanced by the bus bar 18 arranged on the surface of the multilayer printed board 11 as compared with the case where only the copper foil pattern 14 is routed.

It shows the implementation form of the present invention in FIG.
In this embodiment, the bus bar 18 superimposed on the outermost copper foil pattern 14A is divided bus bars 18A and 18B which are superimposed on the copper foil patterns 14A-1 and 14A-2 arranged with a gap S therebetween. The opposed divided ends of the divided bus bars 18A and 18B are respectively bent to erect the press contact terminals 18b.
A jumper wire w is bridged between the press contact terminals 18b and 18b, and both ends of the jumper wire w are press connected to the press contact terminals 18b and 18b.
Since the jumper wire w is located away from the surface of the multilayer printed circuit board 11, another bus bar 18C is disposed on the surface of the multilayer printed circuit board 11 in the gap S between the divided bus bars 18A and 18B in a non-contact manner with the jumper wire w. is doing.
The conductor disposed in the gap S may be an electric wire or a copper foil pattern 14.

FIG. 4A shows a reference second embodiment.
In the reference second embodiment, the bus bar 18 is used as a connection conductor for four circuits.
The bus bar 18 is provided with a quadrangular concentrated connecting portion 18d at the tip of a pattern portion 18c arranged so as to overlap the required copper foil pattern 14A, and the end portions of the other copper foil patterns 14B to 14D are overlapped with the concentrated connecting portion 18d. Connected.
Topology of the bus bar 18 and the copper foil pattern 14A～14 D is omitted because it is similar to the reference first embodiment.

  With the above configuration, the allowable current value of the copper foil pattern 14A on which the pattern portion 18c of the bus bar 18 is superimposed is increased, and the copper foil pattern 14A is connected to the copper foil patterns 14B to 14D on which other bus bars are not superimposed. Can do.

4B and 4C show a modification of the reference second embodiment. As shown in FIG. 4B, only the copper foil patterns 14A, 14B, and 14C are formed with the central connection portion 18d of the bus bar 18 having an L shape. Is connected.
In FIG. 4C, the bus bar 18 has a shape capable of connecting two copper foil patterns 14A and 14B and 14C and 14D, respectively.
In this way, the connection circuit can be arbitrarily changed by changing the shape of the concentrated connection portion 18d of the bus bar 18.

Showing a reference third embodiment of the present invention in FIG.
In the reference embodiment, the bus bar 18 is also provided with a through hole 18 e, and the through hole 18 e is communicated with the through hole 16 provided in the multilayer printed board 11. The conductive metal pin 21 is passed through the through holes 16 and 18e communicated with each other.
Solder 19 is filled between the inner peripheral surface of the communicating through holes 16 and 18 e and the outer peripheral surface of the conductive metal pin 21 in a state where the conductive metal pin 21 is penetrated.
Thus, the bus bar 18 and the multilayer printed board 11 are fixed by the solder 19, and the bus bar 18 and the copper foil pattern 14 of each layer are electrically connected via the solder 19 and the conductive metal pin 21.

The depending arrangement, similarly to the reference first embodiment, with each copper foil pattern 14 can be inter-connected, it is possible to form a large current circuit by the bus bar 18.
Further, in the present reference embodiment, by penetrating the conductive metallic pins 21 into the through hole 18e of the through hole 16 and the bus bar 18 of the multilayer printed board 11, positioning the bus bar 18 to the multilayer printed circuit board 11 prior to filling the solder 19 This can facilitate the filling work of the solder 19.
In addition, since another structure and an effect are the same as that of reference 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

It is a disassembled perspective view of the electrical-connection box which accommodates the circuit material of the reference 1st embodiment of this invention. It is a principal part expanded sectional view of the circuit material of a reference 1st embodiment. It shows the implementation form of the present invention, (A) is a perspective view, (B) is a cross-sectional view. (A) is a schematic plan view which shows reference 2nd Embodiment, (B) (C) is a schematic plan view which shows the modification of reference 2nd Embodiment. It is a principal part expanded sectional view of the circuit material of a reference 3rd embodiment. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Circuit material 11 Multilayer printed circuit board 14 (14A-14D) Copper foil pattern 16 Through-hole 17 Plating 18 Bus-bar 18A, 18B Division | segmentation bus-bar 18a Closure part 18b Press-contact terminal 18c Pattern part 18d Concentration connection part 18e Through-hole 19 Solder 20 Electrical connection box 21 Conductive metal pin

Claims (5)

A circuit material housed in an in-vehicle electrical junction box,
A through hole for connecting the copper foil pattern of the multilayer printed board to the interlayer is provided, and a bus bar is disposed on at least a part of the surface of the copper foil pattern of the outermost layer of the multilayer printed board, and a part of the bus bar is the through hole. Located on the opening surface of
The bus bar and the multilayer printed circuit board are fixed to each other with solder filling the through hole, and the bus bar and the copper foil pattern on the inner and outer layers of the multilayer printed circuit board are electrically connected , and the bus bar is divided into bus bars. The divided bus bars are arranged on the copper foil patterns of different circuits on the surface of the multilayer printed circuit board and connected to each other, and terminals are projected from the divided ends of the divided bus bars. Connect, and
Wherein said jumper wire multilayer between a printed circuit board surface, the circuit member to accommodate a different busbar or electrical connection box are arranged wires.   The circuit accommodated in the electrical connection box according to claim 1, wherein one end opening of the through hole is closed by the bus bar, and solder filled from the other end opening of the through hole is fixed to the closing portion of the bus bar. Wood.   A through hole communicating with one end opening of a through hole provided in the multilayer printed board is provided in the bus bar, and a conductive metal pin is penetrated through the communicated through hole, and the conductive metal pin and the inner peripheral surface of the through hole are provided. The circuit material accommodated in the electrical junction box according to claim 1, wherein the conductive metal pin, the bus bar, and the copper foil pattern of each layer are connected via solder to be filled. 4. The circuit according to claim 1, wherein one bus bar is arranged and fixed on a copper foil pattern of a circuit having a different surface on the multilayer printed circuit board, and the circuit connection of the copper foil pattern is performed by the bus bar. A circuit material accommodated in the electrical junction box according to item 1. An in-vehicle electrical junction box containing the circuit material according to any one of claims 1 to 4.

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