JPH0370918B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] Printing in which a flexible printed wiring board having a terminal portion protruding outward from the rigid printed wiring board is bonded to a rigid printed wiring board of a predetermined shape via an insulating adhesive layer. A method for manufacturing a wiring composite board, the method comprising: preparing a rigid printed wiring board plate having a size that includes a developed outline including protruding terminal portions of a flexible printed wiring board having a predetermined shape; It is used as a reinforcing backing for flexible printed wiring boards during bonding or soldering work, and is used to cut along the contour of the flexible printed wiring board after the specified bonding and soldering work is completed. It is possible to improve the efficiency of soldering work.

[Industrial application field]

The present invention relates to a method for manufacturing a flexible printed wiring board and a rigid printed wiring board, which are formed by bonding a flexible printed wiring board and a rigid printed wiring board via an insulating adhesive layer, and particularly to a method for manufacturing a flexible printed wiring board. The present invention relates to a technique for connecting through holes and through holes or connection patterns of a rigid printed wiring board using a solder leveler. Note that the term "flexible printed wiring board" herein refers to a flexible printed wiring board, and the term "rigid printed wiring board" refers to a rigid printed wiring board.

In recent years, there has been a strong demand for electronic devices to be lighter, thinner, shorter, and more compact, and to improve productivity.In response to these demands, we have developed rigid substrates that are excellent for component mounting, planar wiring, and planar circuit configurations, and flexible substrates that can be used for three-dimensional wiring configurations. A composite board has been developed that is formed by combining and bonding excellent flexible boards and has the function of a multilayer wiring board and the connection function of a flexible board.

One important point in the construction of this type of composite board is the quality of the electrical connection between the flexible board and the rigid board by soldering.

[Conventional technology]

In such a flexible and rigid printed wiring composite board, a flexible printed wiring board (hereinafter referred to as an FPC board) and a rigid printed wiring board (hereinafter referred to as an RPC board) are bonded via an adhesive layer made of an insulating adhesive. Electrical connection between the two boards is made by connecting through holes formed at predetermined positions on the FPC board and corresponding through holes or connection patterns formed on the RPC board using solder.

Conventionally, this soldering method has had to rely on individual manual work using a soldering iron or the like. Another possibility is the solder dip method, in which the entire board is immersed in a solder bath, but in this method, even through-holes for mounting electronic components and other parts that do not require soldering are soldered, so a solder resist is applied to the parts that do not require soldering. However, it is troublesome to apply the resist and remove the resist after soldering is completed.

By the way, a solder leveler is known as an efficient method for soldering. This is done by blowing hot air on the dip-soldered parts when they are pulled up from the solder bath to blow away the solder on parts that are not wettable by solder, that is, parts where no solder is needed.At the same time, the excess solder on the solder parts is also removed. This allows a thin and uniform solder finish to be obtained. However, since this solder leveler blows hot air at high speed as described above, it is necessary that the parts to be soldered have rigidity.

[Problem that the invention seeks to solve]

However, the above-mentioned solder leveler could not be applied to the printed wiring composite board, which is the subject of the present invention, for the following reasons. That is, the flexible printed wiring board allows the terminal portion to extend in any direction from the rigid printed wiring board to enable three-dimensional wiring or multilayer wiring, but the terminal portion of the flexible printed wiring board can extend outward from the rigid printed wiring board. This is because the terminal portion lacks rigidity because there is no rigid printed circuit board to support it, and hot air cannot be blown onto it.

An object of the present invention is to enable the use of a solder leveler to improve the soldering workability of a printed wiring composite board, and to simplify the manufacturing process.

[Means for solving problems]

As a means for solving the above problems, in the present invention, as illustrated in FIGS. 1 and 2, a terminal portion 5 is provided on a rigid printed wiring board 11 having a predetermined shape and protrudes outward from the rigid printed wiring board. When manufacturing a printed wiring composite board in which a flexible printed wiring board 1 having a flexible printed wiring board 1 is bonded via an insulating adhesive layer 21, a rigid printed wiring board of a size that includes the expanded outline including the protruding terminal portion of the flexible printed wiring board is used. A plate 13 for the rigid printed wiring board and a sheet 23 for the adhesive layer are prepared, and the plate for the rigid printed wiring board has a cutout in advance at a portion where the protruding terminals of the flexible printed wiring board intersect with the external shape of the rigid printed wiring board having a predetermined shape. In addition to forming the groove holes 15, cutout openings 25 corresponding to the protruding terminals of the flexible printed wiring board are formed in advance in the sheet for the adhesive layer, and the plate for the rigid printed wiring board and the sheet for the adhesive layer are formed in advance. There is provided a method for manufacturing a printed wiring composite board, which is characterized in that the rigid printed wiring board is cut along the contour after completion of predetermined bonding and soldering operations.

[Effect]

Until the soldering work is completed, the rigid printed wiring board is also provided below the protruding terminal portion 5 of the flexible printed wiring board as a supporting backing, so that rigidity is ensured. Therefore, hot air can be blown at high speed during soldering work using a solder leveler. When the soldering work is completed, a final product similar to the conventional one can be obtained by cutting out the parts of the rigid printed wiring board corresponding to the protruding terminals of the flexible printed wiring board.

〔Example〕

FIG. 1 is an exploded perspective view of a printed wiring composite board for explaining one embodiment of the present invention, and FIG. 2 is an external perspective view of the embodiment of the present invention.

1 and 2, reference numeral 1 is a flexible printed wiring board (hereinafter referred to as FPC), 11 is a rigid printed wiring board (hereinafter referred to as RPC board), and 21 is a rigid printed wiring board (hereinafter referred to as RPC board).
1 and 2 respectively show adhesive layers made of an insulating adhesive which are interposed between the substrates 1 and 11 and bond them together.

An example of the appearance of the printed wiring composite board obtained by the present invention is as shown in FIG.
It is bonded to the entire surface of the RPC board 11 via an adhesive layer 21, a connection part Q is provided at a predetermined position, and a part of the edge of the FPC board 1 is extended to form a bent terminal 5, and a three-dimensional It is formed to be wireable, and is thereby formed into a composite board that has the function of a multilayer wiring board and the function of connecting with other FPC boards.

The manufacturing method according to the present invention is as follows.

First of all, the plate piece 3 that makes up the FPC board 1 and the plate piece 1 that makes up the RPC board 11.
3 and a sheet 23 constituting the adhesive layer 21 are prepared. These plate pieces 3, 13 and sheet 2
3 preferably have the same size, for example, a rectangular or square shape. Its size is shown in the exploded view.
The size includes the protruding terminals 5 of the FPC board 1.
Each plate piece 3, 13 and sheet 23 have through holes 7, 1 in advance according to a predetermined wiring pattern.
7 and 27 are formed, and electrical connection between the FPC board 1 and the RPC board 13 is achieved through these through holes.

The plate piece 13 has the outline of the RPC board 11 and
A notch slot 15 is formed in advance along the edge of the FPC board 1 where the protruding terminal 5 intersects. On the other hand, the sheet 23 has an opening 2 having a shape corresponding to the protruding terminal 5.
5 is preformed. The length of the notch slot 15 is equal to or greater than the length of the corresponding portion of the corresponding projecting terminal 5. The protruding terminal 5 corresponds to the size of the opening 25.
greater than or equal to the outline of A predetermined wiring pattern is formed on the plate pieces 3 and 13 by printing or thin film technology.

After joining the plate pieces 3, 13, 13, for example, dip them in a solder bath (not shown) and remove unnecessary portions of the solder by blowing hot air at high speed when pulling them out of the solder bath. do. That is, soldering work is performed using a solder leveler. According to the present invention, at this point, the RPC board plate piece 13, which is a rigid body, is adhered to the entire bottom surface of the FPC board plate piece 1 via the sheet 23, so that the RPC board plate piece 13, which is a rigid body, is attached to the entire bottom surface of the FPC board plate piece 1. There is no need to worry about the FPC board deforming or breaking even when hot air is blown at high speed. In other words, since the RPC board plate 13 functions as a reinforcing backing for the FPC board plate 3, a solder leveler can be used.

In this way, solder remains only in the predetermined pattern, land through holes, and through hole connections to form through hole plating and predetermined through hole interconnections.

When the soldering work is completed, the three plate pieces 3 and 13 and the sheet 23 can be cut out simultaneously along the outer contour of the FPC board 1. This cutting can be performed, for example, by mechanical cutters or punching using a press. As a result, RPC
Since notches and grooves 15 are formed in the board plate piece 13 corresponding to the protruding terminals 5, only the portion of the RPC board plate piece 13 corresponding to the RPC board 11 remains. If the notch slot 15 were not present, the part corresponding to the RPC board 11 and the other parts of the RPC board plate piece 13 would remain connected at this part, and it would be necessary to separate only the part corresponding to the RPC board 11 from the others. I can't.

Similarly, since an opening 25 is formed in the sheet 23 at a portion corresponding to the protruding terminal, by cutting the FPC board plate piece 3 along the outer contour of the FPC board 1, only the protruding terminal 5 portion of the FPC board 1 can be cut. Only the shape portion corresponding to the shape excluding the shape will be left uncut. It will be understood that without the opening 25, the adhesive layer would also adhere to the lower surface of the protruding terminal 5, which would be a problem.

In addition, each plate piece 3, 13 and the sheet 23 can be continuously cut out from the strip material by a press or the like.
The shape of the tip is not limited to that shown in the drawings, and may be, for example, circular, triangular, or other polygonal or irregular shapes.

Further, the FPC board 1 is prepared as a plate at the outer ring part from the beginning, and it is not necessarily necessary to prepare a rectangular plate piece 3 as shown in the figure.

〔Effect of the invention〕

As described above, the RPC board is left as a backing material to reinforce the entire surface of the FPC board until the soldering work is completed, and it is cut into a predetermined shape after the soldering process is completed, resulting in efficient soldering using a solder leveler. This makes it possible to simplify the manufacturing process of flexible-rigid printed wiring composite boards.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a printed wiring composite board for implementing the present invention, and FIG. 2 is an external perspective view of the printed wiring composite board obtained by the present invention. 1 is a flexible printed wiring board (flexible printed wiring board: FPC board), 3 is a plate piece for a flexible printed wiring board, 5 is a protruding terminal, 7 is a through hole, 11 is a rigid printed wiring board (rigid printed wiring board: RPC board), 13 is a plate piece for a rigid printed circuit board, 15 is a notched slot, 21 is an adhesive layer, 23 is a sheet for the adhesive layer, and 25 is an opening.

Claims (1)

[Claims] 1. A printed wiring composite board is manufactured by bonding a flexible printed wiring board 1 having a terminal portion 5 protruding outward from the rigid printed wiring board 11 with an insulating adhesive layer 21 onto a rigid printed wiring board 11 having a predetermined shape. At this time, a rigid printed wiring board plate 13 and an adhesive layer sheet 23 having a size that includes the expanded outline including the protruding terminal portions of the flexible printed wiring board are prepared, and the rigid printed wiring board plate is printed with flexible printing. Notches and slots 15 are formed in advance at the portions where the protruding terminals of the wiring board intersect with the external shape of the rigid printed wiring board having a predetermined shape, and the adhesive layer sheet is adapted to accommodate the protruding terminals of the flexible printed wiring board. Notch opening 2
5 is formed in advance, and the rigid printed wiring board plate and the adhesive layer sheet are cut along the outline of the flexible printed wiring board after predetermined adhesion and soldering work is completed. A method for manufacturing a printed wiring composite board.