JP2008054449A - Circuit material housed in electric connection box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure electrical connection reliability of an electronic component to be mounted on a bus bar while ensuring heat radiation of a portion where the bus bar is fixed, by employing solder connection having high heat radiation for connection between copper foil pattern and the bus bar, in a circuit material in which the bus bar is fixed on the copper foil pattern to increase a permissible current. <P>SOLUTION: In the circuit material to be housed in an on-vehicle electrical connection box, the bus bar having a width not more than the width of the copper foil pattern is fixed on at least one part of the surface of the copper foil pattern of a printed board via a high melting point solder, an electric component is mounted on the printed board with a low melting point solder, the electric component is made of a through-hole or surface-mounting relay or fuse, a first terminal to be connected to a large current side of the relay or fuse is connected to a portion where the bus bar is stuck, and the other second terminal is connected to only the copper foil pattern. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a circuit material housed in an electrical connection box, and in a circuit material including a power supply circuit in which a bus bar is fixed to a copper foil pattern, the electrical connection of electrical components mounted on a printed circuit board while satisfying the heat dissipation of the power supply circuit This is to ensure reliability.

Conventionally, a printed circuit board printed with a 105 μm thick copper foil pattern is usually used as a printed circuit board accommodated in a main power distribution box such as a junction box in an in-vehicle electrical junction box. The allowable current value per 1 mm circuit width of the foil pattern is 6A.
However, when a relay or the like is mounted on a printed circuit board, a large current is required. In this case, it is necessary to increase the allowable current value by increasing the width or thickness of the copper foil pattern.

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. On the other hand, if the thickness of the copper foil pattern is 105 μm or more, 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.
Conventionally, by connecting a conductive metal plate to a copper foil pattern, an allowable current value per 1 mm of circuit width is increased, and a circuit component that requires a large current is mounted on a printed circuit board. . In this case, the conductive metal plate is fixed to the printed board with an adhesive or solder.

For example, in the circuit board disclosed in Japanese Patent Laid-Open No. 10-56244 (Patent Document 1), as shown in FIGS. 7A and 7B, a thick conductor 2 is pasted on an insulating substrate 1 with an adhesive or solder 3 or the like. The terminal pattern 4 is printed on the insulating substrate 1 so as to overlap the thick conductor 2 at the portion located at the end 2 a of the thick conductor 2, and the joined solder flows into the hole 2 b provided in the thick conductor 2. Thus, the thick conductor 1 and the terminal pattern 4 are connected to increase the allowable current value of the circuit board. The circuit component is soldered by inserting a terminal into a through hole 4 a provided in the terminal pattern 4.
According to the configuration of the circuit board, the circuit component and the thick conductor 2 are electrically connected via the terminal pattern 4 without directly connecting the circuit component to the thick conductor 2 having a large heat capacity and difficult to solder. This makes it easy to solder circuit components.

However, when the thick conductor 2 and the insulating substrate 1 are joined by solder, the thick conductor 2 is heated by heat generated from the solder flowing into the hole 2b of the thick conductor 2 when the circuit component is soldered to the terminal pattern 4. As a result, the solder between the insulating substrate 1 and the thick conductor 2 and the insulating substrate 1 are displaced, and the electrical connection reliability is lowered.
Further, even if the thick conductor 2 and the insulating substrate 1 are joined with an adhesive, the adhesive has a low thermal conductivity, so that the heat dissipation from the thick conductor 2 and the insulating substrate 1 is reduced, and the Heat generation cannot be efficiently radiated, and circuit components mounted on the circuit board may cause problems.

JP-A-10-56244

  In the circuit material in which the bus bar is fixed to the copper foil pattern to increase the allowable current, the present invention prevents misalignment even if the copper foil pattern and the bus bar are connected by soldering, and the bus bar is fixed. The problem is to ensure the heat dissipation of the part and ensure the electrical connection reliability of the electronic components mounted on the bus bar.

In order to solve the above problems, the present invention is a circuit material housed in an on-vehicle electrical junction box,
A bus bar having a width equal to or less than the width of the copper foil pattern is fixed to at least a part of the surface of the copper foil pattern of the printed board via a high melting point solder, and electrical components are mounted on the printed board with a low melting point solder. A circuit material accommodated in an electrical junction box is provided.

  Specifically, the present invention prints high melting point cream-like solder (hereinafter abbreviated as cream solder) on the surface of the copper foil pattern, places a bus bar on the surface, and then heats it to increase the height. The melting point solder is melted, and the copper foil pattern and the bus bar are formed by a reflow soldering method that fixes the copper bar pattern and the bus bar via the high melting point solder, and the bus bar is fixed integrally on the copper foil pattern of the printed board via the solder layer. . In this way, after the bus bar is integrated with the copper foil pattern via the solder layer, the low melting point solder having a melting temperature lower than that of the high melting point solder is used, and the electrical component is mounted on the printed circuit board by the flow soldering method. is doing.

  With the above configuration, when mounting an electrical component, the melting point of the solder that fixes the bus bar to the copper foil pattern is higher than the melting point of the solder that mounts the electrical component such as a relay on the printed circuit board. Even if low-melting-point solder flows in the flow process during component mounting, the high-melting-point solder that fixes the bus bar and the copper foil pattern does not melt, and the bus bar does not cause a positional shift with respect to the copper foil pattern.

  In addition, the allowable current value at the bus bar adhering part can be the total energization amount of the three conductors of the copper foil pattern, the solder and the bus bar, including the energization amount of the solder layer, and the allowable current value per 1 mm of the circuit width It can be greatly improved. As a result, there is no need to increase the width of the copper foil pattern or bus bar, it does not affect the circuit pattern of the copper foil pattern, and it is not necessary to increase the thickness of the copper foil pattern or the solder layer, The work process is not increased.

The electrical component comprises a through-hole type or surface mount type relay or fuse, and a first terminal connected to the large current side of the relay or fuse is connected to a copper foil pattern to which the bus bar is fixed, and another second It is preferable that the terminal is connected to a copper foil pattern to which the bus bar is not fixed.
When the electrical component is a relay, the terminal on the contact side through which a large current flows is the first terminal, and the terminal on the coil side connected to the switch is the second terminal.

With the above configuration, since the large current circuit portion in which the bus bar is fixed to the copper foil pattern via the solder layer is provided on the printed board, and the relay and the fuse are mounted on the large current circuit portion, the printed circuit board is the main circuit material. Thus, the circuit material can be simplified and downsized, and as a result, the electrical junction box that accommodates the circuit material can be downsized and reduced in weight.
The electrical component is not limited to a relay, but can be applied to a board-mounted fuse that does not require maintenance. In the case of a fuse, the input terminal is the first terminal and the output terminal is the second terminal.

  When the electrical component is a through-hole type, the first terminal of the electrical component is solder-connected to the copper foil pattern and the bus bar through the through hole formed in the printed circuit board and the bus bar, and the second terminal Is connected to the copper foil pattern through a through hole formed in the printed circuit board, and the solder connected to the first and second terminals is the low melting point solder.

With the above configuration, the power supply side circuit of the electrical component is connected to the bus bar regardless of whether the bus bar and the electrical component are disposed on the same surface or different surfaces with respect to the printed circuit board. Can do.
Further, since the solder for connecting the terminal is the low melting point solder, the solder fixing the bus bar and the copper foil pattern does not melt when the first terminal of the electrical component is soldered and fixed to the bus bar. The electrical connection reliability between the bus bar and the copper foil pattern can be ensured.

The mounting surface of the electronic component of the printed circuit board is different from the fixing surface of the bus bar,
The first terminal of the electrical component has an L shape with a protruding portion from the through hole as a bent portion, the bent portion is brought into contact with the bus bar, and the first terminal is soldered to the copper foil pattern and the bus bar. It is preferable.
If it does in this way, the contact area of a bus-bar and a 1st terminal can be increased by bending a protrusion part, and electrical connection reliability can be improved. In addition, the electrical component can be positioned and held before the electrical component is soldered to the printed circuit board.

  When the electrical component is a surface mounting type, the first terminal and the second terminal of the electrical component have an L shape with a tip as a horizontal portion, and the horizontal portion of the first terminal is fixed to the surface of the copper foil pattern. The solder connected to the first and second terminals is placed on the bus bar and soldered while the horizontal portion of the second terminal is placed on the surface of the copper foil pattern and soldered. The low melting point solder is used.

Specifically, it is used when the arrangement surface of the bus bar and the electrical component is the same, the electronic component is placed at a predetermined position, the electronic component is fixed with a jig, and the electronic component is printed on the printed circuit board by flow soldering. Fix it.
Since the solder for terminal connection is the low melting point solder, when the first terminal of the electrical component is soldered and fixed to the bus bar, the solder fixing the bus bar and the copper foil pattern is not melted. The electrical connection reliability of the copper foil pattern can be ensured.

  As described above, according to the present invention, the low melting point solder is used in the flow soldering process when mounting the electrical component on the printed circuit board in which the bus bar is fixed to the copper foil pattern with the high melting point solder. The high melting point solder that fixes the bus bar and the copper foil pattern does not melt. Therefore, in the electrical component mounting process, the bus bar can be prevented from being displaced with respect to the printed circuit board. As a result, the electrical connection reliability between the bus bar and the copper foil pattern can be ensured even after the electrical component is mounted. .

  Moreover, since the allowable current value per circuit width of 1 mm can be greatly increased, there is no need to increase the width of the copper foil pattern or bus bar, the circuit pattern of the copper foil pattern is not affected, and the copper foil pattern Therefore, it is not necessary to increase the thickness of the solder and the thickness of the solder layer, so that the work process is not increased.

  In addition, a large current circuit part with a bus bar fixed to a copper foil pattern via a solder layer is provided on the printed circuit board, and relays and fuses are mounted on the large current circuit part. Electrical components such as relays and fuses for connecting terminals can be connected to the power circuit side consisting of a large current circuit portion on the printed circuit board and the load circuit side consisting only of a copper foil pattern. Therefore, it is not necessary to provide the power supply circuit material separately from the printed circuit board, the circuit material can be simplified and downsized, and the electrical connection box that accommodates the circuit material can be downsized and reduced in weight. .

Embodiments of the present invention will be described with reference to the drawings.
1 to 5 show a first embodiment of a circuit material of the present invention.
As shown in FIG. 1, the circuit material 10 is housed in an on-vehicle electrical connection box 20, and a relay 30 is mounted on the surface of the circuit material.
As shown in FIG. 2, the circuit material 10 has a large current circuit portion in which a bus bar 13 made of a conductive metal plate is fixed to a part of a copper foil pattern 12 printed on the surface of a printed board 11 via solder. 14 is provided. A relay 30 is mounted on the printed board 11.
In FIG. 1, a large number of terminals protrude from the printed circuit board 11, but the number of protruding terminals is omitted in the figure.

Of the copper foil pattern 12 provided on the surface of the printed circuit board 11, a pattern portion serving as a power supply circuit is the large current circuit portion 14. One surface of the printed board 11 is a bus bar fixing surface 11f for fixing the bus bar, and the other surface is a relay mounting surface 11g for mounting the relay, and the surface for fixing the bus bar 13 and the surface for mounting the relay 30 are different. .
2, the circuit member 10 in FIG. 2 is turned upside down to accommodate the bus bar fixing surface 11f as a lower surface, and terminal portions 13c and 13d formed on the bus bar 13 described later are terminals of the printed circuit board 11. It protrudes upward through the insertion hole 11d.

  The relay 30 mounted on the circuit material 10 is a through-hole type, and the power input side of the connection terminal on the contact side through which a large current flows is the input side first terminal 30a, and the power output side is the output side first terminal 30b. It is said. The connection terminal on the coil side connected to the indoor switch is the second terminal 30c.

  The large current circuit portion 14 of the copper foil pattern 12 includes an input side pattern 12a on the power input side and an output side pattern 12b on the power output side, and the input side pattern 12a and the output side pattern 12b are arranged to face each other. . The end portions of the input side and output side patterns 12a and 12b are used as a relay connection portion 12c, and the other end portions are used as a power input portion 12d and a power output portion 12e. Further, a copper foil pattern 12 that does not fix the bus bar 13 in parallel is provided in the proximity of the input side pattern 12a and the output side pattern 12b.

The relay connection portion 12c is provided with an input side through hole 11a and an output side through hole 11b in communication with the printed circuit board 11 and the bus bar 13. The input side through hole 11a and the output side through hole 11b serve as insertion holes for the input side first terminal 30a and the output side first terminal 30b of the relay 30, respectively.
A pair of through holes 11c penetrating the printed circuit board 11 is provided on the copper foil pattern 12 adjacent to the relay connecting portion 12c, and the second terminals 30c of the relay 30 serve as insertion holes in these through holes 11c.

The solder that forms the solder layer by connecting the bus bar 13 and the copper foil pattern 12 is the high melting point solder 15 having a melting point of about 240 ° C. The high melting point solder 15 is printed on the surface of the copper foil pattern 12 to which the bus bar 13 is fixed, in the form of cream solder with a required thickness that is less than the width of the copper foil pattern 12. After the bus bar 13 is placed on the surface of the applied cream solder, it is heated and melted at a temperature higher than the melting point to fix and fix the copper foil pattern 12 and the bus bar 13.
Specifically, a metal mask obtained by cutting out a portion of the copper foil pattern 12 to be the large current circuit portion 14 is placed on the surface of the printed circuit board 11, and the high melting point solder 15 is applied to the entire surface of the copper foil pattern 12 to be the large current circuit portion 14. It is applied. The high melting point solder 15 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.

The bus bar 13 is formed by punching a conductive metal plate along the copper foil pattern 12 of the large current circuit portion 14, and the bus bar 13 soldered to the input side pattern 12a on the power input side is connected to the input side. On the other hand, the bus bar 13 soldered to the output side pattern 12b on the power output side is used as the output side bus bar 13b. The width of the bus bar 13 is set to be equal to or smaller than the width of the copper foil pattern 12 (preferably the same width) so as not to protrude from the copper foil pattern 12.
At both ends of the bus bar 13, a tab-like input terminal portion 13c and an output terminal portion 13d that serve as terminals for the power input portion and the power output portion are integrally formed by bending. The input and output terminal portions 13c and 13d are penetrated through a terminal insertion hole 11d provided in the printed board 11 and protruded toward the relay mounting surface 11g of the printed board 11.

  As shown in FIG. 3, a printed circuit board 11 in which a bus bar 13 is fixed to a copper foil pattern 12 with a high melting point solder 15 has a relay 30 mounted thereon with its relay mounting surface 11g facing upward. The solder used for mounting the relay 30 is a low melting point solder 16 having a melting point of about 220 ° C., and a solder having a melting point lower than that of the high melting point solder 15 that fixes the bus bar 13 to the copper foil pattern 12. The high melting point solder 15 is prevented from melting in the soldering process with the solder 16.

The relay 30 mounted on the printed circuit board 11 is printed through the input side through hole 11a and the output side through hole 11b formed in the printed circuit board 11 and the bus bar 13 with the input side first terminal 30a and the output side first terminal 30b. The board 11 protrudes from the bus bar fixing surface 11f. The protruding portion is soldered with a molten low melting point solder 16, and the input side and output side first terminals 30 a and 30 b of the relay 30 are soldered to the copper foil pattern 12 and the bus bar 13.
On the other hand, the second terminal 30c of the relay 30 is protruded from the bus bar fixing surface 11f through a through hole 11c formed in the printed board 11. The protruding portion is soldered with a molten low melting point solder 16 to be connected to the copper foil pattern 12 by soldering.

Next, a procedure for creating the circuit material 10 of this embodiment will be described.
First, the cream-like high melting point solder 15 is applied to the surface of the copper foil pattern 12 with the bus bar fixing surface 11f as the upper surface.
Next, the input and output terminal portions 13c and 13d of the bus bar 13 are inserted into the terminal insertion holes 11d, and the printed circuit board 11 is inserted into a reflow furnace (not shown) with the bus bar 13 disposed on the copper foil pattern 12. Then, the high melting point solder 15 is heated at a melting temperature, and the front surface of the copper foil pattern 12 and the back surface of the bus bar 13 are fixed by the molten high melting point solder 15. The melted solder is solidified to form a solder layer between the copper foil pattern 12 and the bus bar 13.

Next, the relay mounting surface 11g is used as the top surface, and the input side first terminal 30a and the output side first terminal 30b of the relay 30 are inserted into the input side through hole 11a and the output side through hole 11b, and the second terminal 30c is connected to the second terminal 30c. The first terminals 30a and 30b and the second terminal 30c are inserted into the through hole 11c and protrude from the bus bar fixing surface 11f of the printed board 11.
Next, the printed circuit board 11 is inserted into a flow solder bath (not shown), and the low melting point solder 16 is poured into the protruding portions of the first terminals 30a and 30b and the second terminal 30c to solidify the low melting point solder 16. The printed circuit board 11, the first terminals 30a and 30b, and the second terminal 30c are connected by soldering. The same applies when a fuse is mounted.

With this configuration, when the relay 30 is mounted after the bus bar 13 is fixed to the copper foil pattern 12 with the high melting point solder 15, the melting point of the solder for attaching the bus bar 13 to the copper foil pattern 12 is set to the relay 30. Since the melting point of the solder to be mounted is higher than the melting point of the solder to be mounted, the high melting point of the solder bus bar 13 and the copper foil pattern 12 is fixed even if the low melting point solder 16 flows through the printed circuit board 11 in the flow process when the relay is mounted. The solder 15 does not melt. Therefore, the electrical connection reliability between the bus bar 13 and the copper foil pattern 12 can be maintained even after the relay is mounted. Further, it is possible to prevent the displacement of the bus bar 13 with respect to the printed circuit board 11 caused by melting of the high melting point solder 15.
Further, the allowable current value in the large current circuit portion 15 can be set to the total energization amount of the three conductors of the copper foil pattern 12, the high melting point solder 15, and the bus bar 13 by adding the energization amount of the high melting point solder 15. The allowable current value per 1 mm of the large current circuit unit 15 as the power supply circuit can be increased, and the allowable current amount can be greatly increased.

FIG. 4 shows a second modification of the first embodiment, wherein the protruding portions of the first terminals 30a and 30b are L-shaped with bent portions 30g, and the bent portions 30g are solder-connected to the bus bar 13. .
In this case, by providing the bent portion 30g, the contact area between the bus bar 13 and the first terminals 30a and 30b can be increased, and the electrical connection reliability can be improved. In addition, the relay 30 can be positioned and held before the relay 30 is soldered to the printed circuit board 11.

  FIG. 5 shows a second embodiment of the circuit material 10 according to the present invention, in which the mounting surface of the relay 30 is flush with the fixing surface 11 h of the bus bar 13. The first terminals 30a and 30b and the second terminal 30c of the relay 30 are inserted through the bus bar 13 and the input side of the printed circuit board 11, the output side through holes 11a and 11b, and the through hole 11c, and are opposite to the bus bar fixing surface 11h. The first terminals 30a and 30b and the second terminal 30c are projected from the surface, and the first terminals 30a and 30b and the second terminal 30c are connected to the printed board 11 by soldering.

Next, a procedure for creating the circuit material 10 of this embodiment will be described.
As in the first embodiment, the bus bar 13 is soldered to the copper foil pattern 12 with a high melting point solder 15. Next, the input side first terminal 30a and the output side first terminal 30b of the relay 30 are inserted into the input side through hole 11a and the output side through hole 11b from the bus bar fixing surface 11h, and the second terminal 30c is inserted into the second through hole 11c. The first terminals 30a and 30b and the second terminal 30c are protruded from the opposite surface of the printed circuit board 11.

Thereafter, the low melting point solder 16 is poured into the protruding portions of the first terminals 30a, 30b and the second terminals 30c by a flow soldering method, and the solder is filled into the input side and output side through holes 11a, 11b to fix the bus bar. The bus bar 13 on the surface 11f side and the input side and output side first terminals 30a and 30b are solder-connected, and the copper foil pattern 12 and the second terminal 30c are solder-connected.
This embodiment can be applied when the mounting surface of the relay is on the same surface as the bus bar constituting the large current circuit unit.
In addition, since another structure and an effect are the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

6A and 6B show a third embodiment of the circuit material 10 of the present invention.
In the present embodiment, the relay 30 is a surface mount type, the printed circuit board is not provided with a through hole, and the mounting surface of the relay 30 is the same surface as the fixing surface 11 h of the bus bar 13. The first terminals 30a and 30b and the second terminal 30c of the relay 30 have an L shape with tips at the horizontal portions 30d, 30e, and 30f.
The horizontal portions 30d and 30e of the input side and output side first terminals 30a and 30b are placed on the input side bus bar 13a and the output side bus bar 13b and connected by solder, and the horizontal portion 30f of the second terminal 30c. Are placed on the surface of the copper foil pattern 12 and connected with solder.

Next, a procedure for creating the circuit material 10 of this embodiment will be described.
As in the first embodiment, the bus bar 13 is solder-connected to the copper foil pattern 12 with a high melting point solder 15. The horizontal portions 30d and 30e of the input and output side first terminals 30a and 30b are placed on the input and output bus bars 13a and 13b, and the horizontal portion 30f of the second terminal 30c is placed on the copper foil pattern. The relay 30 is fixed with a fixing jig (not shown). In this state, the printed circuit board is inserted into the flow solder tank, the low melting point solder is jetted into the horizontal portions 30d, 30e, 30f of the relay 30, and the first terminals 30a, 30b and the second terminals 30c are connected to the copper foil pattern 12 and The bus bar 13 is soldered.
This embodiment can be applied to the case where the mounting surface of the relay is the same surface as the bus bar constituting the power supply circuit and the relay is a surface mounting type.
In addition, since another structure and an effect are the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

It is a disassembled perspective view of the electrical junction box which accommodates the circuit material of 1st Embodiment of this invention. It is a disassembled perspective view which shows the circuit material of 1st Embodiment. (A) is the top view to which the principal part of the circuit material which mounted the relay was expanded, (B) is the sectional view on the AA line of (A). It is a schematic sectional drawing which shows the 1st modification of 1st Embodiment. It is a schematic sectional drawing which shows 2nd Embodiment. It is a figure which shows the circuit material of 3rd Embodiment, (A) is the top view to which the principal part of the circuit material which mounted the relay was expanded, (B) is a BB sectional drawing of (A). . It is a figure which shows a prior art example, (A) is the top view to which the principal part of the circuit board was expanded, (B) is CC sectional view taken on the line of (A).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Circuit material 11 Printed circuit board 11a Input side through hole 11b Output side through hole 11c Through hole 12 Copper foil pattern 13 Bus bar 15 High melting point solder 16 Low melting point solder 20 Electrical connection box 30 Relay 30a Input side first terminal 30b Output side first Terminal 30c Second terminal

Claims (5)

A circuit material housed in an in-vehicle electrical junction box,
A bus bar having a width equal to or less than the width of the copper foil pattern is fixed to at least a part of the surface of the copper foil pattern of the printed board via a high melting point solder, and electrical components are mounted on the printed board with a low melting point solder. A circuit material housed in an electrical junction box.   The electrical component comprises a through-hole type or surface mount type relay or fuse, and a first terminal connected to the large current side of the relay or fuse is connected to a copper foil pattern to which the bus bar is fixed, and another second The circuit material accommodated in the electrical junction box according to claim 1, wherein the terminal is connected to a copper foil pattern to which the bus bar is not fixed.   The electrical component is a through-hole type, and a first terminal of the electrical component is connected to a copper foil pattern and the bus bar through a through-hole formed in the printed circuit board and the bus bar, and the second terminal is 3. The electrical connection box according to claim 2, wherein the solder connected to the copper foil pattern is passed through a through hole formed in the printed circuit board, and the solder connected to the first and second terminals is the low melting point solder. Circuit material. The mounting surface of the electronic component of the printed circuit board is different from the fixing surface of the bus bar,
The first terminal of the electrical component has an L shape with a protruding portion from the through hole as a bent portion, the bent portion is brought into contact with the bus bar, and the first terminal is soldered to the copper foil pattern and the bus bar. The electrical junction box according to claim 3. The electrical component is a surface mount type, and the first terminal and the second terminal of the electrical component have an L shape with a tip as a horizontal portion, and the horizontal portion of the first terminal is fixed to the surface of the copper foil pattern. While the solder is placed on the bus bar and soldered, the horizontal portion of the second terminal is placed on the surface of the copper foil pattern and soldered, and the solder connected to the first and second terminals is the The circuit material accommodated in the electrical junction box according to claim 2, which is a low melting point solder.

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