JPH06342981A - Manufacture of printed circuit board - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a printed circuit board in which the hard board of high quality to be selectively peeled and removed can be manufactured in a mass production and high yield without the necessity of a complicated step and a special facility. CONSTITUTION:A method for manufacturing a printed circuit board comprises the steps of laminating and integrating hard printed circuit boards 2, 2' having separating grooves 3a, 3b partly selectively cut and separated at predetermined positions through an adhesive layer on a main surface of a flexible board 1, and forming an outer layer circuit 2e on the hard boards 2, 2' by photoetching. When the circuit 2e is formed on the boards 2, 2' to be cut and removed by the grooves 3a, 3b, a disposable pattern 2f remains.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board, and more particularly to a method for manufacturing a printed wiring board which is composed of a hard printed wiring unit section and a flexible section and can be bent.

[0002]

2. Description of the Related Art Conventionally, the following structure has been used as a circuit structure that also serves as a wiring connection portion that requires flexibility, a device housing, or as a stacked or compact wiring or circuit unit. A foldable printed wiring board is known. That is, on the surface of the flexible wiring board, hard printed wiring board units are laminated and integrated as appropriate,
There is known a printed wiring board that can be bent by using a flexible wiring board that forms the separation portion. FIG. 3 is a cross-sectional view of the structure of the main parts of such a foldable printed wiring board, and FIG. 4 is a plan view of the structure of the main parts. Reference numeral 1 denotes a required wiring pattern (not shown). The flexible printed circuit boards 2 and 2'provided are rigid printed circuit boards integrally provided on both main surfaces of the flexible printed circuit board 1 via adhesive layers (not shown), and 3 is the hard printed circuit board. For example, along the sides of the wiring unit portions 2a, 2b, facing the bending portion 3 at the bending portion with the wiring unit portions 2a, 2b provided in the hard printed wiring boards 2, 2'as a unit, The V-grooves 3a and 3b are formed in a configuration. In this structure, the hard printed wiring boards 2 and 2'are separated by the V grooves 3a and 3b, and the non-circuit forming areas 2c and 2c 'between the wiring unit portions 2a and 2b on the same surface are selectively peeled off. -By removing, the flexible wiring board 1 is exposed and can be bent.

A printed wiring board of this type is generally manufactured as follows. That is, an adhesive layer (sheet or coating layer) of epoxy resin or the like is previously arranged on the surface of the flexible wiring board 1 and a bendable portion (hinge portion) is formed on the adhesive layer surface.
Positioning of hard printed wiring boards 2 and 2'with V-grooves 3a provided on the area surface corresponding to 3 and covered with copper foil (not shown),
After arranging and stacking, pressure and heat are integrated. In this process, the hard printed wiring boards 2 and 2'that form the outer layer board
After the outer shape is processed, the non-circuit forming areas (flexible areas) 2c and 2c 'are adhered to the V-grooves 3a and 3b without an adhesive in order to facilitate selective peeling and removal. The agent layer is arranged.

As described above, after the hard printed wiring boards 2 and 2'are integrated on the surface of the flexible wiring board 1, the outermost copper foil 2d is photo-etched to form the required wiring pattern. Through hole connection 4
And V-grooves 3a, 3b on the inner surface while performing external processing
The V-shaped groove (not shown) corresponding to the above is formed outside the hard printed wiring boards 2 and 2 '. Here, the non-circuit forming regions 2c and 2c 'are wiring unit portions.
It functions as a cover material (lid) for protecting the portion of the flexible wiring board 1 that is finally exposed by the etching patterning 2e of 2a and 2b, and as shown in FIG. The wiring boards 2 and 2'are removed by peeling using the peeling projection 2d which has been cut out beforehand.

[0005]

However, in the method of manufacturing the printed wiring board, the following disadvantages are recognized in practical use. That is, when the non-circuit forming regions 2c and 2c 'on the surface of the flexible wiring board 1 are peeled and removed to expose a part of the flexible wiring board 1, the peeling convex portion 2d is easily cut to form a hard printed wiring board. Plate 2,
There is a problem that a complicated operation and time are required to selectively remove the non-circuit forming regions 2c and 2c 'of 2'. That is, in the printed wiring board, when the non-circuit forming regions 2c and 2c ′ are set small, the peeling convex portion 2d is necessarily set to be thin, or the hard printed wiring board 2, in view of compactness. When the thickness of 2'is set to be thin, in order to selectively remove the non-circuit forming regions 2c, 2c ', if the non-circuit forming regions 2c, 2c' are peeled off by using the peeling projection 2d. In many cases, the peeling convex portion 2d may not be attached or may be broken in the middle, and the required peeling cannot be achieved. The breakage of the peeling protrusion 2d is caused by the non-circuit forming region.
Not only the peeling / removal of 2c and 2c ′ becomes difficult and the workability is significantly lowered, but also the exposed area surface of the flexible wiring board 1 is damaged, resulting in deterioration of the quality of printed wiring boards and reduction of yield. There is an inconvenient problem.

The present invention has been made in order to solve the above problems, and is of high quality that does not require complicated steps or special equipment, and can selectively peel and remove a hard printed wiring board. It is an object of the present invention to provide a manufacturing method capable of mass-producing such a printed wiring board with good yield.

[0007]

SUMMARY OF THE INVENTION A method of manufacturing a printed wiring board according to the present invention is a hard printed board provided with slits or grooves for cutting and separating at a predetermined position and selectively removing a part thereof. A method for manufacturing a printed wiring board, comprising: a step of laminating and integrating a wiring board on a main surface of a flexible substrate via an adhesive layer; and a step of forming an outer layer circuit on a hard printed wiring board surface by photoetching. It is characterized in that a waste pattern is left when the outer layer circuit is formed on the surface of the hard printed wiring board that is cut, separated and removed by the slit or the groove for separation.

In the above manufacturing process, a weir for preventing the outflow of the adhesive is previously formed and arranged between the laminated surfaces of the hard printed wiring board and the flexible board corresponding to the areas to be cut, separated and removed. It is preferable to keep. That is, it is possible to control the region where the adhesive flows out to the surface of the flexible substrate and the adhesive remains and adheres, so that it is possible to easily improve the design and assembly precision in systematization.

[0009]

According to the method of manufacturing a printed wiring board according to the present invention, since the printed wiring board can be bent in units of the hard wiring unit, the hard printed wiring board area is selectively peeled and removed. For example, a copper pattern is formed on the surface, and the hard printed wiring board region to be peeled off / removed by the copper pattern has a reinforced form. Therefore, since the flexible substrate surface is exposed, when selectively peeling / removing a predetermined area of the hard printed wiring board, for example, a fear of cutting or breaking of a peeling convex portion is eliminated. Selective peeling / removing workability and quality / yield will be greatly improved / improved.

[0010]

Embodiments of the present invention will be described below with reference to FIGS.

First, hard printed wiring boards 2 and 2'having a wiring pattern on one main surface and a copper foil (not shown) stretched on the other main surface are prepared. 2 '
Of the wiring pattern is formed along the periphery of the wiring unit on the surface where the wiring pattern is formed, for example, using the Victoria mold to form the required separation grooves 3a and 3b, while the separation grooves 3a and 3b are formed. A peeling convex portion 2d continuous with an area surrounded by (a non-circuit forming area described later) was formed by punching. Here, on the copper foil surface side of the hard printed wiring boards 2 and 2 ', the wiring unit portions 2a and 2b forming regions and the wiring unit portion 2a are formed corresponding to the wiring unit portion whose one main surface is a wiring pattern. , 2b separating the non-circuit forming regions 2c, 2c '
It is divided into Then, the separation groove 3a,
3b is provided along the periphery of the wiring unit parts 2a and 2b, and the grooves 3a and 3b for separating are deep enough to reach the copper foil surface stretched on the other main surface.

On the other hand, a flexible substrate 1 having required wiring patterns (not shown) provided on both main surfaces,
And an adhesive sheet (not shown) are prepared.
Here, the adhesive sheet is cut out (opened) between the grooves 3a and 3b for separating the hard printed wiring boards 2 and 2 ', that is, the portions corresponding to the non-circuit forming regions 2c and 2c'. The shape and size are set. That is, after the lamination and integration by heating and pressure molding, which will be described later, the adhesive layer flows out to the lower side of the non-circuit forming regions 2c, 2c 'so as not to participate in the adhesive action.

Next, after laminating and arranging the prepared hard printed wiring boards 2 and 2 ', the flexible substrate 1 and the adhesive sheet, a heating / pressurizing process is carried out so that both sides of the flexible substrate 1 are hard. Printed wiring board 2,
A printed wiring board in which 2'are integrated is obtained. Thereafter, the outer layer copper foil corresponding to the wiring unit portions 2a and 2b of the integrated hard printed wiring boards 2 and 2'is subjected to a required photoetching treatment to form the outer layer circuit 2e, and at the same time, the non-circuit is formed. Also for the outer layer copper foils corresponding to the formation regions 2c and 2c ', for example, a discard pattern 2f having a width of about 0.3 mm on both sides of the non-circuit formation regions 2c and 2c' is formed. Further, if necessary, the through-hole connection 4 is formed to obtain a desired bendable printed wiring board.

The present invention is not limited to the above embodiments, and various modifications can be adopted without departing from the scope of the invention. For example, the cut surfaces of the hard printed wiring boards 2 and 2'which are integrally laminated on the flexible substrate 1 do not have to be linear. That is, the non-circuit forming regions 2c and 2c 'may be arbitrarily set according to the outer layer circuit pattern or the like.

[0015]

As described above, according to the method for manufacturing a printed wiring board of the present invention, a preset position / area is selectively peeled / removed from the flexible substrate surface, and the area is a bendable area. And a highly reliable printed wiring board can be easily obtained. That is, in the manufacturing process, the part that is selectively peeled / removed has a form reinforced beforehand by setting a discard pattern, so when mechanically pulling / cutting off, the part to be peeled does not cut in the middle. Since the required selective peeling / removal can be achieved easily and surely without causing damage to the circuit structure, a printed wiring board having high accuracy and reliability can be manufactured with high yield. Further, it can be said that, together with the fact that the compactness of the circuit mechanism due to the foldability can be easily achieved, it brings many practical advantages.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structural example of a main part of a printed wiring board obtained by a manufacturing method according to the present invention.

FIG. 2 is a plan view showing a structural example of a main part of a printed wiring board obtained by a manufacturing method according to the present invention.

FIG. 3 is a cross-sectional view showing a structural example of a main part of a printed wiring board obtained by a conventional manufacturing method.

FIG. 4 is a plan view showing a structural example of a main part of a printed wiring board obtained by a conventional manufacturing method.

[Explanation of symbols]

1 ... Flexible substrate 2, 2 '... Hard printed wiring board 2a, 2b ... Wiring unit 2c, 2c' ... Non-circuit forming area 2d ... Peeling convex portion 2e ... Outer layer circuit 2f ... Discard pattern 3 ... Bending portion 3a, 3b … V-groove 4… Through hole connection

Claims (1)

[Claims] 1. A hard printed wiring board provided with a cutting groove capable of cutting / separating at a predetermined position and selectively removing a part thereof is laminated on a main surface of a flexible substrate via an adhesive layer.
In a method for manufacturing a printed wiring board, which comprises a step of integrating and a step of forming an outer layer circuit on the surface of the hard printed wiring board by photo-etching, a hard printed wiring that is cut / separated by the cutting groove and removed. A method for manufacturing a printed wiring board, characterized in that a waste pattern is left when the outer layer circuit is formed on the board surface.