JP3826669B2 - Circuit board and connection method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit board and a connection method thereof.
[0002]
[Prior art]
For example, in a vehicle such as an automobile, an electrical connection box for electrically connecting a flexible printed circuit board is used. This type of electrical junction box accommodates a plurality of flexible printed circuit boards (FPCs) having a conductor pattern therein. Then, the flexible printed boards are overlapped and the conductive portions of the conductor pattern are spot welded or soldered to electrically connect the flexible printed boards.
[0003]
However, in such a method, since it takes time to perform welding and soldering, the manufacturing efficiency is low and the cost is high. As a result, there is a problem that it is not suitable for mass production. Therefore, conventionally, as a method of connecting the conductive portions of the flexible printed circuit board at low cost and in a short time, the conductive portions of the flexible printed circuit board are connected by ultrasonic welding.
[0004]
[Problems to be solved by the invention]
However, the horn provided in the ultrasonic welding apparatus is brought into contact with the conductive portion provided in the flexible printed circuit board, and the horn is vibrated in this state. Therefore, the flexible printed circuit board is affected by the vibration. Is easily misaligned. As a result, the conductor patterns are not welded at an appropriate position, which may lead to a decrease in reliability.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a circuit board capable of improving reliability by preventing poor welding of a conductive portion provided on the board body and its connection. It is to provide a method.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention according to claim 1, a plurality of substrate bodies having a plurality of conductive portions arranged in parallel on the surface are positioned by overlapping a plurality of pieces on the anvil so that the respective conductive portions face each other. In the circuit board in which the conductive portions are ultrasonically welded to each other by a horn that moves along the direction in which the conductive portions are arranged, the conductive portion is formed by exposing the conductive pattern from the insulating material. The conductive portions are arranged in a straight line, and positioning holes for positioning the substrate body at a predetermined position are arranged between the adjacent conductive portions, and the positioning holes are engaged with the locking projections of the anvil. The gist is to be combined .
[0007]
In the invention of claim 2, a plurality of conductive portions formed by exposing the conductor pattern from the insulating material are arranged in a straight line on the surface, and positioning holes are arranged between adjacent conductive portions to form a substrate body. A plurality of the substrate main bodies are overlapped so that the respective conductive portions are opposed to each other, and a large number of locking projections are formed on the anvil at regular intervals, and each positioning hole of the substrate main body has each locking of the anvil. The substrate body is placed on the anvil so as to be engaged with the protrusion and positioned, and a horn that can be brought into and out of contact with the conductive portion is brought into contact with the conductive portion in the positioned state, thereby making each conductive The gist is that the parts are ultrasonically welded and the anvil is moved along the direction in which the conductive parts are juxtaposed after the welding .
[0009]
The “action” of the present invention will be described below.
According to the first and second aspects of the invention, the substrate body is positioned in the vicinity of the conductive portion provided on the substrate body by the positioning portion, and the conductive portion is welded in this state. For this reason, the conductive portions facing each other are less likely to be displaced due to vibrations generated during ultrasonic welding. As a result, poor welding of the conductive part can be prevented.
[0010]
Further , since the positioning portion is disposed between the adjacent conductive portions, the substrate body is positioned at a position closer to the vibration generation source. Therefore, poor welding of the conductive part can be reliably prevented.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment embodying the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, flexible printed circuit boards (FPCs) 11 and 12 as substrate bodies are made of conductive patterns 11a and 12a made of copper foil and a polyimide film as an insulating material covering the conductive patterns 11a and 12a. Are bonded together with an adhesive.
[0012]
Part of the conductor patterns 11a and 12a is exposed to the outside. Here, part of the conductor patterns 11a and 12a is exposed on both the front and back surfaces of the flexible printed boards 11 and 12, respectively. That is, the polyimide films on both surfaces of the conductive portions 11b and 12b are removed. The exposed portions are the conductive portions 11b and 12b of the flexible printed circuit board 11. A large number of the conductive portions 11b and 12b are arranged along the edge of the flexible printed circuit board 11 at a predetermined interval. Yes.
[0013]
The flexible printed boards 11 and 12 are overlapped so that the conductive parts 11b and 12b face each other, and the conductive parts 11b and 12b are connected to each other by ultrasonic welding. In the vicinity of the conductive portions 11b and 12b, a large number of positioning holes 14 are formed as positioning portions for preventing the displacement of the flexible printed boards 11 and 12 when ultrasonic welding is performed. Here, each positioning hole 14 is arrange | positioned between each adjacent electroconductive part 11b, 12b, respectively. In short, each positioning hole 14 is arranged on the arrangement line of the conductive portions 11b and 12b.
[0014]
Next, an ultrasonic welding apparatus will be described.
As shown in FIGS. 2 and 3, the ultrasonic welding device 20 includes an anvil 21 that can move along the direction in which the conductive portions 11 b and 12 b are arranged. On the upper surface of the anvil 21, a support portion 22 is provided to support the conductive portions 11 b and 12 b of the flexible printed circuit boards 11 and 12. A large number of rectangular parallelepiped locking projections 23 are formed on the upper surface of the support portion 22 at regular intervals. The interval between the locking projections 23 is substantially equal to the interval between the positioning holes 14. Then, when the flexible printed boards 11 and 12 are placed on the anvil 21, the locking projections 23 are engaged with the positioning holes 14. By this engagement, both the flexible printed boards 11 and 12 are positioned.
[0015]
Above the anvil 21, a horn 25 that can approach and separate from the locking projection 23 is provided. With the bottom surface of the horn 25 in contact with the conductive portions 11b and 12b of the flexible printed circuit boards 11 and 12, ultrasonic vibration is applied from the horn 25, whereby frictional heat is applied to both the conductive portions 11b and 12b. Is generated, and the conductive portions 11b and 12b facing each other are welded. .
[0016]
Next, a method for connecting the flexible printed circuit boards 11 and 12 configured as described above will be described.
The two flexible printed boards 11 and 12 are overlapped, the conductive portions 11b and 12b are arranged to face each other, and the positioning holes formed in the flexible printed boards 11 and 12 are made to coincide with each other. Next, when both the flexible printed boards 11 and 12 are placed on the anvil 21 and the respective locking projections 23 are engaged with the positioning holes 14, the flexible printed boards 11 and 12 are positioned. . In this state, the horn 25 is brought into contact with the conductive portions 11b and 12b, and ultrasonic vibration is applied, whereby the conductive portions 11b and 12b are welded. Thereafter, the anvil 21 is moved along the arrangement direction of the conductive portions 11 b and 12 b, and the conductive portions 11 b and 12 b to be welded next are disposed to face the tip of the horn 25. Then, a large number of conductive portions 11b and 12b are sequentially welded while the above-described operation is repeated. By these weldings, the flexible printed circuit boards 11 and 12 are electrically connected.
[0017]
Therefore, according to the present embodiment, the following effects can be obtained.
(1) A large number of positioning holes 14 are arranged in the vicinity of the welded portions of the conductive portions 11b and 12b. Then, at the time of welding, the locking projections 23 are engaged with the positioning holes 14 so that the flexible printed boards 11 and 12 are positioned. Therefore, even if the conductive portions 11b and 12b at the locations to be welded are vibrated by the horn 25 of the ultrasonic welding device 20, it is possible to prevent the flexible printed boards 11 and 12 from being displaced. Therefore, it is possible to prevent the conductive portions 11b and 12b from causing poor welding and to improve the reliability.
[0018]
(2) The positioning hole 14 is disposed in the vicinity of the welded portions of the conductive portions 11b and 12b. Therefore, even if there is a difference between the shrinkage amount of the conductor patterns 11a and 12a and the shrinkage amount of the polyimide film due to heat generated at the time of welding, there is a dimensional change in the flexible printed circuit boards 11 and 12. It can be prevented from occurring.
[0019]
(3) A positioning hole 14 is formed between the conductive portions 11b and 12b arranged on a straight line. That is, the flexible printed circuit boards 11 and 12 are positioned at a position closest to a place where vibration is generated during welding. Accordingly, the conductive portions 11b and 12b can be reliably welded.
[0020]
(4) The polyimide film as an insulating material is removed on both surfaces of the conductive portions 11b and 12b provided on the flexible printed circuit boards 11 and 12, respectively. Therefore, the conductive portions 11b and 12b can be completely welded without being disturbed by the polyimide film.
[0021]
(5) Since the conductive portions 11b and 12b of the flexible printed circuit boards 11 and 12 are arranged in a straight line, the flexible printed circuit board 11 can be formed by welding sequentially from the conductive portions 11b and 12b located on one end side. , 12 can be reduced. Therefore, when there are a large number of conductive portions 11b and 12b, they can be quickly welded and the welding efficiency can be improved.
[0022]
In addition, you may change embodiment of this invention as follows.
In the embodiment, the positioning hole 14 is formed between the adjacent conductive portions 11b and 12b. In addition to this, the positioning hole 14 may be formed at an arbitrary position as long as it is in the vicinity of the group of the conductive portions 11b and 12b.
[0023]
-In the said embodiment, it embodied in the welding of flexible printed circuit boards 11 and 12. In addition, a rigid printed circuit board (PCB) and a flexible printed board may be ultrasonically welded.
[0024]
Next, listed technical ideas grasped by the previous mentioned with the embodiments below.
(1) before Symbol positioning portion, the circuit board, characterized in that formed on the substrate main body, a locking hole anvil provided on the ultrasonic welding device is engaged.
[0025]
(2) prior Symbol both sides of the conductive portion provided on the substrate main body, the circuit board, wherein an insulating material is coated on the surface of the substrate main body has been removed. With this configuration, the conductive portion can be completely welded.
[0026]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to improve reliability by preventing poor welding of the conductive portion provided in the substrate body.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a flexible printed circuit board according to an embodiment.
FIG. 2 is an exploded perspective view showing a flexible printed board and an ultrasonic welding apparatus.
FIG. 3 is a perspective view when welding a flexible printed circuit board.
[Explanation of symbols]
11, 12 ... flexible printed circuit board (board body), 11b, 12b ... conductive portion,
14 ... positioning hole (positioning part).

Claims (2)

A substrate body having a plurality of conductive parts arranged in parallel on the surface is positioned by superimposing a plurality of substrates on the anvil so that the conductive parts are opposed to each other, and each conductive part is conducted by a horn that moves along the direction in which the conductive parts are arranged. In a circuit board that is designed to ultrasonically weld parts together,
The conductive portion is formed by exposing a conductive pattern from an insulating material, the conductive portions are arranged in a straight line, and a positioning hole for positioning the substrate body at a predetermined position is adjacent to each conductive portion. And the positioning holes are engaged with the locking projections of the anvil . A large number of conductive parts with conductor patterns exposed from an insulating material are arranged in a straight line on the surface, and positioning holes are arranged between adjacent conductive parts to form a board body. The board body is opposed to each conductive part. A plurality of stacking projections are formed on the anvil at regular intervals, and the positioning holes of the substrate body are engaged with the locking projections of the anvil. The substrate body is placed on the anvil and positioned, and a horn that can be brought into and out of contact with the conductive portion is brought into contact with the conductive portion in the positioned state to ultrasonically weld the conductive portions to each other. method of connecting that circuitry substrate to, characterized in that after the welding is moved along the arrangement direction of the anvil conductive portion.

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