JPH08162757A - Method for interconnecting printed wiring boards with cable - Google Patents

Abstract

PURPOSE: To facilitate the alignment of connection terminal by making a slit in the dummy plate part at the position corresponding to the outer peripheral part of a plurality of printed wiring boards and connecting a flexible cable through the slit with a pad on the printed wiring board. CONSTITUTION: Two slits 3a, 3b for arranging the intermediate part 9 of a flexible cable 7 along the back face side of a dummy plate part 2 are made, while being spaced apart specifically from each other, in the dummy plate part 2 located between a plurality of printed wiring boards 1a, 1b. Pads 5a, 5b are arranged at such positions as the longitudinal direction of the slits 3a, 3b will be normal to the direction of P-P line connecting the pads 5a, 5b to be connected electrically. The opposite connection terminals 8a, 8b of the flexible cable 7 can be aligned with the pads 5a, 5b through the two slits 3a, 3b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting cables between printed wiring boards, and more particularly to a method for connecting printed wiring boards by a flexible cable when the printed wiring boards are formed as a collective board by a discard plate portion. On how to do it.

[0002]

2. Description of the Related Art FIGS. 3 to 5 show a conventional example in which a plurality of printed wiring boards are connected by a flexible cable.

[0003] In FIG. 4, reference numerals 51a and 51b denote printed wiring boards, and reference numeral 57 denotes a printed circuit board.
The flexible cable which electrically connects 1a and 51b is shown. Here, as shown in the figure, the flexible cable 57 is often used in which a plurality of conducting wires are bundled in parallel.

Further, each printed wiring board 51a, 51b
Has a flexible cable 5 on the surface near its outer periphery.
7, pads 55a, 55b made of copper foil for connecting
Is provided, and solder 56 is applied in advance on the pads 55a and 55b.

Next, a cable connection method in this conventional example will be briefly described with reference to FIG.

First, one connection terminal 58a of the flexible cable 57 is aligned with the position of the pad 55a on the one printed wiring board 51a by using an alignment jig (not shown) or the like (FIG. 3A).

[0007] Then, the connection terminal 58a is heated by a heater 59 such as a heat tool to melt the solder, thereby forming one connection terminal 58a of the flexible cable 57.
Is soldered onto the pad 55a of the printed wiring board 51a (FIG. 3 (B)).

Next, for the other printed wiring board 51b, similarly, the other connection terminal 58b of the flexible cable 57 is aligned with the position of the pad 55b of the printed wiring board 51b (FIG. 3C).

Then, the solder 56 is melted by a heater 59 such as a heat tool to connect the connection terminal 58b (FIG. 3).
(D)).

As a result, one printed wiring board 51
a and the other printed wiring board 51b are electrically connected (FIG. 3 (E)), and finally the discarding plate portion 52 is cut off (FIG. 3 (F)), and the process of the conventional cable connecting method is completed. finish.

[0011]

However, when a plurality of printed wiring boards are connected by a flexible cable by the above-described conventional method, there are the following problems. That is, when aligning the connection terminal of the flexible cable with the pad, one connection terminal of the flexible cable is connected to the pad of the printed wiring board in FIG.
As shown in (1), there is an annoyance that it is necessary to simultaneously perform positioning in three directions, ie, the vertical direction on the paper, the horizontal direction on the paper, and the horizontal rotation direction on the paper.

Therefore, even in the first step (FIG. 3A) of aligning one of the connection terminals, it is very difficult to perform the alignment, and a lot of man-hours for the alignment are required, and the alignment is performed. It is easy to make mistakes, and it takes time to correct these mistakes. Also, when a jig for positioning is used, the cost and man-hours required for making the jig are increased, and the use of the jig requires a lot of man-hours.

Here, the above-mentioned problems become more remarkable as the pitch between the connection terminals of the flexible cable becomes smaller, and the electric parts are mounted on the printed wiring board with high density and the electric circuit is formed with high density. That was a particular problem.

[0014]

An object of the present invention is to improve the inconvenience of the prior art and, in particular, when connecting a plurality of printed wiring boards with a flexible cable, connecting terminals of the flexible cable to pads on the printed wiring board. It is an object of the present invention to simplify the connection process and to improve the connection quality by facilitating the alignment.

[0015]

According to a first aspect of the present invention, there is provided a method of connecting cables between printed wiring boards, wherein a printed wiring board of at least one and the other printed wiring boards are integrated by a waste plate portion. At the same time, two slit holes for arranging the intermediate portion of the flexible cable along the back side of the waste plate portion are formed at predetermined intervals in the waste plate portion located between the one and the other printed wiring boards. Is adopted.

In addition, this method of connecting cables between printed wiring boards is such that after connecting the middle portion of the flexible cable along the back side of the discarding plate portion through the two slit holes, both flexible cables are connected. The method of connecting the terminals to the pads of each printed wiring board and then cutting off the discarding plate portion is adopted.

In the method of connecting cables between printed wiring boards according to a second aspect of the present invention, when one connection terminal of a flexible cable is aligned with a pad of one printed wiring board, the other connection terminal of the flexible cable is the other. The length of the flexible cable is set to a predetermined length in advance so that it can be aligned with the pad of the printed wiring board, and other configurations are the same as those of the first aspect.

Further, in the cable connecting method between the printed wiring boards according to the third aspect, the inner wall surface of each slit hole on the side of each printed wiring board is set at a position corresponding to the outer peripheral surface of each printed wiring board. The configuration is adopted, and the other configurations are the same as those of claim 1 or 2.

Further, the cable connecting method between the printed wiring boards according to claim 4 has a configuration in which the length of each slit hole is slightly longer than the width of the flexible cable, and the other configuration is claimed. It is the same as 1, 2, or 3.

This is intended to achieve the above-mentioned object.

[0021]

In the sacrificial plate portion located between the one and the other printed wiring boards, an intermediate portion of the flexible cable having a predetermined length is arranged along the back side of the sacrificial plate portion. Form the slit holes of the book at a predetermined interval,
After arranging the middle part of the flexible cable along the back side of the discard plate part through these two slit holes, connect both connecting terminals of the flexible cable to the pads of each printed wiring board, and then the discard plate part. Excise.

Therefore, the connection terminals of the flexible cable can be easily aligned with the pads of the printed wiring board.

Thus, when connecting a plurality of printed wiring boards with a flexible cable, the process of connecting the connection terminals of the flexible cable to the pads on the printed wiring board can be simplified, and the connection quality is improved. be able to.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 2A is a sectional view of the printed wiring board after the two printed wiring boards have been connected to each other by a flexible cable, and FIG. 2B is a plan view thereof. Here, reference numerals 1a and 1b each indicate a printed wiring board, and reference numeral 7 indicates a flexible cable.

First, referring to FIG. 2, the printed wiring board 1
a and 1b are formed of a glass epoxy material or a polyimide-based insulating base material. This printed wiring board 1a,
On 1b, a metal foil made of copper foil or the like is laminated on the surface thereof via an adhesive layer, and unnecessary portions of the metal foil are removed by etching, whereby an arbitrary electric circuit pattern is formed. Further, on this electric circuit pattern, an electric component is actually mounted and assembled (not shown).

The printed wiring boards 1a and 1b form a collective board 1 integrated by a discard plate 2 provided around the printed wiring boards 1a and 1b. This is because the printed wiring boards 1a, 1a, 1
b is required to be thin and lightweight, and there arises a problem such as warpage of the board itself when assembling electric parts to the printed wiring boards 1a and 1b. That is, by disposing the discarding plate portion 2 on a part or the whole of the printed wiring boards 1a and 1b and reinforcing the printed wiring boards 1a and 1b, this warpage that occurs during mounting of electrical components is reduced and assembly is facilitated. It is intended. . At present, a very thin printed wiring board, for example, a board thickness of 0.4 [m]
m] and 0.6 [mm] are also used.

Further, on the printed wiring boards 1a and 1b, pads 5a and 5b for connecting the flexible cable 7 are provided at portions substantially corresponding to the outer peripheral portions of the printed wiring boards 1a and 1b, and the pads 5a and 5b are flexible. Solder 6 for connecting the cable 7 is applied.

Further, a plurality of printed wiring boards 1a, 1b
A flexible cable 7 is attached to the discard plate 2 located between
The two slit holes 3a and 3b for arranging the intermediate portion 9 along the back side of the discard plate portion are formed at a predetermined interval. The length of each of the slit holes 3 a and 3 b is formed slightly longer than the width of the flexible cable 7. The width of each slit hole 3a, 3b is about twice the thickness of the flexible cable 7 so that the flexible cable 7 can be inserted. Further, the inner wall surfaces of the slit holes 3a, 3b on the printed wiring board 1a, 1b side are set at positions corresponding to the outer peripheral surfaces of the printed wiring boards 1a, 1b.

The pads 5a and 5b have slit holes 3
The longitudinal direction of a, 3b and the line PP connecting the pads 5a, 5b to be electrically connected to each other are arranged at positions perpendicular to each other.

Further, the surface of the flexible cable 7 is covered with an insulating member, and the conductive members are exposed at both ends to form connection terminals 8a and 8b. In addition, the flexible cable 7 aligns the two connection terminals 8a, 8b with the pads 5a, 5b via the two slit holes 3a, 3b. At this time, in the flexible cable 7, when one connection terminal 8a is aligned with the pad 5a of the one printed wiring board 1a portion, the other connection terminal 8b can be aligned with the pad 5b of the other printed wiring board 1b portion. Is set in advance to a predetermined length.

Next, a method of connecting cables between the printed wiring boards of the present invention will be described with reference to FIG.

First, the flexible cable 7 having a predetermined length is arranged on the front surface side of the printed circuit board 1 (FIG. 1A).

Next, of the two connecting terminals 8a and 8b of the flexible cable 7, the connecting terminal 8b located on the right side in FIG. 1 is provided on the discarding plate portion 2 on the left side of the printed wiring board 1a in FIG. It is inserted into the slit hole 3a.

Next, the connecting terminals 8b of the flexible cable 7 protruding to the rear surface side of the collective substrate 1 are connected to the surface side of the collective substrate 1 through the slit holes 3b provided in the discarding plate portion 2 on the right printed wiring board 1b side. Again (Fig. 1
(B)).

Then, the connection terminal 8a on the left side of the flexible cable 7 is connected to the pad 5 on the printed circuit board 1a on the left side.
(a) is aligned with the correct position on (a) (FIG. 1 (C)).

Thus, the relationship between the length of the discard plate 2 and the shapes of the slit holes 3a and 3b and the flexible cable 7
The other connection terminal 8b of the flexible cable 7 can also be aligned with the correct position on the pad 5b from the relationship between the length and the width.

Here, the specific contents of the positioning are shown in FIG.
1 and 2 will be described in comparison with the conventional example shown in FIG.

First, since the two slit holes 3a and 3b are formed slightly longer than the width of the flexible cable 7, the slit holes 3a and 3b of the flexible cable 7 are formed.
Is unnecessary in the longitudinal direction (see FIG. 5B). Further, since the flexible cable 7 is inserted into the two slit holes 3a and 3b formed at a predetermined interval, it is not necessary to position the flexible cable 7 in the horizontal rotation direction (FIG. 5C). reference). Therefore, if one of the connection terminals of the flexible cable 7 is positioned at the correct position of the corresponding pad in the vertical direction on the paper (see FIG. 5A), the printed wiring boards 1a and 1b can be easily and simultaneously placed at two places. The connection terminals 8a, 8b of the flexible cable 7 can be aligned with the pads 5a, 5b.

The solder 6 is applied to the pads 5a and 5b of the printed wiring boards 1a and 1b in advance by solder plating, solder cream printing, or the like. Here, the solder 6 is melted by heating both connection terminals 8a and 8b of the flexible cable 7 simultaneously or one by one with the heater 11 (FIG. 1 (D)). Thus, the connection terminals 8a and 8b of the flexible cable 7 can be connected to the pads 5a and 5b of the printed wiring boards 1a and 1b by soldering. The heating device 11 uses a heat tool or the like.

From the above, a plurality of printed wiring boards 1
a and 1b can be easily connected by the flexible cable 7. After this solder connection, the discarded plate portion 2 is cut off by a cutting machine such as a press type, so that the printed wiring boards of the present embodiment can be cut off. The process of the cable connection method ends (FIG. 1E).

The connection terminals 8a, 8b of the flexible cable 7 and the pads 5 on the printed wiring boards 1a, 1b
An anisotropic conductive film or the like may be used for connection with a and 5b.

[0043]

According to the first aspect of the present invention, a slit hole is provided in the discard plate portion at a position corresponding to the outer peripheral portion of the plurality of printed wiring boards, and the flexible cable is placed on the printed wiring board through the slit hole. In this case, the position of the connection terminal can be easily adjusted as compared with the conventional connection method. Thus, when connecting a plurality of printed wiring boards with a flexible cable, the process of aligning the connection terminals of the flexible cable to the pads on the printed wiring board can be simplified, and alignment errors are drastically reduced. Further, it is possible to provide an unprecedented excellent method of connecting cables between printed wiring boards, which can reduce the cost and the number of steps for producing a jig for positioning.

According to the second aspect of the invention, by setting the flexible cable to a predetermined length in advance, in addition to the effect produced by the method according to the first aspect, one connecting terminal can be printed on one side. By aligning with the pad of the wiring board, the other connecting terminal of the flexible cable can be aligned with the pad of the other printed wiring board, thereby providing an unprecedented excellent cable connecting method between the printed wiring boards.

According to the third aspect of the present invention, the inner wall surface of each slit hole on the side of each printed wiring board is set at a position corresponding to the outer peripheral surface of each printed wiring board. Item 1. In addition to the effects produced by the method described in Item 1 or 2, there is an unprecedented excellent inter-printed circuit board-to-printed circuit board position in which the positioning of connection terminals to pads provided near the outer peripheral portion of the printed circuit board becomes very easy. Provide a cable connection method.

Further, according to the invention of claim 4, the length of the slit hole into which the flexible cable is inserted is
Since the width of the flexible cable is made slightly longer than the width of the flexible cable, in addition to the effect produced by the method according to claim 1, the alignment of the flexible cable in the slit hole longitudinal direction and the alignment in the horizontal rotation direction are unnecessary. It is possible to provide an unprecedented excellent method of connecting cables between printed wiring boards.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a connection process according to an embodiment of the present invention. FIG. 1A shows a state before a flexible cable is connected, and FIG. 1C shows a state in which both ends of the flexible cable are aligned, and FIG.
FIG. 1 (D) shows a state in which the flexible cable is soldered by a heater, and FIG. 1 (E) shows a state in which the discard plate portion is cut off.

FIG. 2 is an explanatory diagram of one embodiment of the present invention, and FIG.
Is a cross-sectional view of the collective substrate, and FIG. 2B is a plan view of the collective substrate.

FIG. 3 is a cross-sectional view showing a connection process of a conventional example.
3A shows a state in which one end of the flexible cable is aligned, FIG. 3B shows a state in which the aligned one end is soldered by a heater, and FIG. 3C shows the other end of the flexible cable. 3 (D) shows a state where the aligned other end is soldered by a heater, and FIG. 3 (E) shows a state where the printed circuit boards are electrically connected by a flexible cable. FIG. 3 (F) shows a state where the discarded plate portion is cut off.

FIG. 4 is an explanatory diagram of an embodiment of the present invention, and FIG.
Is a cross-sectional view of the collective substrate, and FIG. 4B is a plan view of the collective substrate.

FIG. 5 is a plan view showing a positioning direction required in a conventional example, and FIG.
FIG. 5B shows the alignment in the left-right direction on the paper surface.
(C) shows the alignment in the direction of rotation of the paper surface.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Assembly board 1a, 1b Printed wiring board 2 Waste board part 3a, 3b Slit hole 4 Slit length 5a, 5b Pad 7 Flexible cable 8a, 8b Connection terminal 9 Middle part 11 Heating machine

Claims (4)

[Claims] 1. A collective board in which at least two printed wiring boards, one and the other, which are connected by a flexible cable, are integrated by a discarding plate portion, and a disposal board located between the one and the other printed wiring boards is provided. Two slit holes for arranging the intermediate portion of the flexible cable along the back side of the discarding plate portion are formed in the plate portion at predetermined intervals, and the flexible portion is formed through the two slit holes. After arranging the middle part of the cable along the back side of the discard plate part,
A method of connecting cables between printed wiring boards, comprising connecting connection terminals at both ends of a flexible cable to pads of each of the printed wiring boards, and then cutting off the discarded plate portions. 2. When aligning both connection terminals of the flexible cable with pads of each printed wiring board, aligning the connection terminals of one flexible cable with the pads of the one printed wiring board,
The length of the flexible cable is set to a predetermined length so that the connection terminal of the other flexible cable can be aligned with the pad of the other printed wiring board. The cable connection method between the printed wiring boards described in the above. 3. The printed wiring according to claim 1, wherein an inner wall surface of each of the slit holes on the side of the printed wiring board is set at a position corresponding to an outer peripheral surface of the printed wiring board. How to connect cables between boards. 4. The cable connecting method between printed wiring boards according to claim 1, wherein the length of each slit hole is slightly longer than the width of the flexible cable.