JPH04326792A - Manufacture of flexible printed wiring board - Google Patents

Abstract

PURPOSE:To facilitate press processing and make it efficient by automating the exfoliation work of a protective sheet material and the work of sticking a film cover lay to a circuit board. CONSTITUTION:A film coverlay 10, to which a protective sheet 11 is stuck by an adhesive 12, is veered out in the longitudinal direction as shown by an arrow A and is carried rectilinearly, and only the protective sheet material 11 is guided in the different direction by a guide roller 15 so as to exfoliate it from the film cover lay 10. A plurality of flexible printed circuit boards 16a, 16b, and 16c are stuck to the film cover lay 10, and then those are temporarily pressure-bonded by a hot platen 17. Both mold-releasing cushion films 21 and 22 are laid on the flexible printed circuit boards 16a, 16b, and 16c and the film coverlay 10 to catch them from both sides, and those are boned at the positions where adhesives 18 are pasted, and at those positions these are cut with a cutter. Hereby, both ends of the mold releasing cushion films are thermocompression-bonded to both sides of each film coverlay, and a member in independent shape can be gotten, and press processing work can be facilitated.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a method for manufacturing a flexible printed circuit board used in electronic equipment, etc., and more specifically, the present invention relates to a method for manufacturing a flexible printed circuit board for use in electronic equipment, etc. The present invention relates to a method for manufacturing a printed wiring board.

0002

[Prior Art] A flexible printed wiring board has a flexible printed circuit board as a base material with a wiring pattern printed on a highly flexible base film using conductors, and electronic components in the wiring pattern are mounted. The conductor circuit portion, except for necessary parts such as lands, contacts, and connection lands, is covered and protected by a film coverlay attached thereto, and its strength is reinforced.

As shown in FIG. 5, the film coverlay 1 is made of an extremely thin and flexible material, so before it is attached to the flexible printed circuit board, it is covered with a release paper or release film that is more rigid than the film coverlay itself. It is attached to the protective sheet material 2 such as. This protective sheet material 2 facilitates processing using a mold or drill when drilling holes in the film coverlay 1 to expose a predetermined surface of the flexible printed circuit board. It protects the adhesive layer 3 coated on one surface.

When attaching the film coverlay 1 to a flexible printed circuit board, as shown in FIG. On the other hand, the film coverlay 1 is cut into a size that is a fraction of the area of the flexible printed circuit board 4, and a plurality of film coverlays 1 are temporarily attached to the conductive surface of the flexible printed circuit board 4 using an adhesive layer 3. It is crimped. The reason why the film coverlay 1 is divided into a plurality of sheets and pasted together in this manner will be explained. First, since the film coverlay 1 that has been peeled off from the protective sheet material 2 is made of extremely thin and stiff material, it is difficult to handle and the pasting process cannot be automated. Since the peeled film coverlay 1 is held in hand and visually positioned and pasted on the flexible printed circuit board 4, the accuracy is inevitably poor even if performed by an experienced person. Second, in recent years, the circuit density and component mounting density of flexible printed wiring boards have tended to become higher and higher, and accordingly, the required holes for exposing conductor patterns on the circuit board 4 formed in the film coverlay 1 have become smaller and smaller. Therefore, high precision is required for positioning this exposure hole with respect to the conductor circuit of the circuit board 4. In order to attach the film coverlay 1 manually with as high precision as possible, the film coverlay 1 is divided into a plurality of sheets and then attached. Also, when setting it on a hot plate press machine in the next process,
Release cushion films 5 are placed on both sides of the circuit board 4 to which the film coverlay 1 is temporarily pressed for the purpose of suppressing variations in pressure distribution during press working and facilitating disassembly after press working.

Next, as shown in FIG. 7, when press working is performed using a pair of hot plates 6 and 7, the work is performed in multiple layers in order to increase the working efficiency per unit time. In such multilayer press working, the cushioning material 8 is used to improve heat transfer and maintain the balance between the hot plates 6 and 7. Therefore, the operator must prepare two cushion materials 8 each.
In the meantime, as shown in "Figure 6", the film coverlay 1 is
The process of inserting a pair of release cushion films 5 on both sides of the circuit board 4 which has been temporarily crimped is repeated for a predetermined number of layers, and then pressing is performed using both hot plates 6 and 7. .

[0006]

However, according to the conventional manufacturing method, a film coverlay 1 divided into a plurality of pieces is attached to a circuit board 4 of a predetermined size so that it can be positioned with a predetermined precision. The operator has to perform the troublesome work of peeling off the film coverlay 1 one by one from the protective sheet material 2. Furthermore, since the film coverlay 1 peeled off from the protective sheet material 2 is made of a stiff material and is difficult to handle, it is necessary to position the holes of the film coverlay 1 and the predetermined conductor patterns of the circuit board 4. It is extremely difficult to do this mechanically, and the pasting work cannot be automated and relies on inefficient manual work by workers.

Furthermore, when performing press processing using the hot plates 6 and 7, the release cushion film 5 cut to the same size as the circuit board 4 of a predetermined size as described above is extremely soft and thin. , this film 5
The work of setting the film coverlay 1 on both sides of each circuit board 4 to which the film coverlay 1 has been temporarily bonded cannot be carried out by a single worker. Therefore, it requires a large number of personnel and is a time-consuming task, which requires a lot of working time, which is a factor in increasing manufacturing costs.

Therefore, the present invention can automate the work of peeling off the protective sheet material and the work of attaching the film coverlay to the circuit board, and can be easily set between hot plates by one worker during press processing. A technical object of the present invention is to provide a method for manufacturing such a flexible printed wiring board.

[0009]

[Means for Solving the Problems] The present invention is a technical means for achieving the above-mentioned problems, in which a flexible printed wiring board is manufactured by the following method. That is, a long film coverlay having a protective sheet material attached to one side with an adhesive layer is perforated at predetermined locations, and then transported in the longitudinal direction under tension. A plurality of flexible printed circuit boards are guided in a direction and peeled off, and a plurality of divided flexible printed circuit boards are positioned on the stretched film coverlay and temporarily pressed with the adhesive layer. Adhesive is applied to both sides of the flexible printed circuit board group in the transfer direction, and a long release cushion film is superimposed on the flexible printed circuit board side and the film coverlay side, and the adhesive is After both the release cushion films are thermocompression bonded to both sides of the film coverlay using the adhesive layer and the adhesive at the adhesion position, the thermocompression bonded portions are cut, and the bonded flexible printed circuit board and the adhesive are bonded together. Both ends of the release cushion film that covers both sides of the film coverlay are crimped to form an integrated crimped block, and the plurality of crimped blocks are inserted between the cushion materials and pressed. It is characterized by going through a process.

0010

[Function] In the manufacturing method of the present invention, since the film coverlay is perforated in an uncut long form, the film coverlay can be easily transported. Peeling work can be automated. In addition, since the film coverlay from which the protective sheet material has been peeled off is transferred under tension in the longitudinal direction, the film coverlay can be held stably even though the material is not stiff, so the position of the film coverlay is can be recognized mechanically or optically, making it extremely easy to attach to flexible printed circuit boards.Furthermore, flexible printed circuit boards made of stiff material can be cut and separated into appropriate sizes to create a film coverlay. Since the film coverlay is attached to the flexible printed circuit board, it is also possible to automate the process of positioning and attaching the film coverlay and the flexible printed circuit board. Furthermore, since the release cushion film, which is made of an extremely thin and flexible material, can be handled as an integral part of the block to be crimped, even one worker can easily insert it between the cushion materials. .

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the drawings. "Figure 1" to "Figure 3"
1 shows a series of steps in a divided manner. First, as shown in FIG. The film coverlay 10 is wound around the roll 13 after holes (not shown) for exposing conductor parts are formed in advance at each predetermined location of the film coverlay 10, and the film coverlay 10 is stretched along the longitudinal direction indicated by the arrow A by applying tension. The protective sheet material 11 is unrolled in a direction and transported linearly, and at the position immediately after unwinding, only the protective sheet material 11 is guided in a different direction by a guide roller 15 and peeled off from the film coverlay 10.
The peeled protective sheet material 11 is wound up on a winding roller 14. In this process, the film coverlay 1
Since the perforation process of the film coverlay 10 is carried out in the uncut long form, it is easy to transport the film coverlay 10, and the long form makes it easy to peel off the protective sheet material 11 as described above. Can be automated.

Next, the flexible printed circuit board on which the conductor pattern has been formed and cut to a size that can be pressed is cut and divided into sizes suitable for crimping, and the plurality of flexible printed circuit boards 16a, 16b, 16c are The conductor portion to be exposed is positioned in the exposure hole described above and bonded to the film coverlay 10 using the adhesive layer 12, followed by temporary pressure bonding using the hot plate 17. In this temporary pressure bonding step, the film coverlay 10 from which the protective sheet material 11 has been peeled off is transferred under tension in the longitudinal direction, so that the film coverlay 10 can be stably moved even though it is made of a stiff material. Since the film coverlay 10 can be held, the position of the film coverlay 10 can be recognized mechanically or optically, and the circuit boards 16a, 16b,
The work of pasting 16c becomes extremely easy. Moreover, the flexible printed circuit boards 16a to 16c are made of sturdy material.
Cut and separate into appropriate sizes and make a film coverlay 10
Therefore, it is also possible to automate the adhesion work by positioning the exposure holes of the film coverlay 10 and the predetermined conductor patterns of the circuit boards 16a to 16c within a permissible range.

Then, as shown in FIG. 2, adhesive 18 is applied to the lower surface of the film coverlay 10 at the front and rear corresponding positions of a set of flexible printed circuit boards 16a, 16b, 16c. , while unwinding the long release cushion films 21 and 22 wound around the rollers 19 and 20 arranged above and below,
The flexible printed circuit boards 16a, 16b, which are attached to each other by changing the direction of the release cushion films 21, 22, respectively, by guide rollers 23, 24,
16c and the film coverlay 10 so that they are overlapped on both sides.

As shown in FIG. 3, when the sticky adhesive 18 is transferred to the crimping area where the pair of hot plates 25 and 26 are placed, both the hot plates 25 and 26 are pressed together as shown by the arrows. Both release cushion films 21 are thermocompression bonded to both sides of the film coverlay 10 by the upper and lower adhesive layers 12 and the adhesive 18. This thermocompression bonded area is cut by a cutter 27 when it is transferred to the cutting section. Therefore, through the series of steps described above, the film coverlay 10 is attached to the plurality of flexible printed circuit boards 16a, 16b, and 16c, and both ends of the release cushion films 21 and 22 attached to both sides of these are bonded to each other. Pressure-bonded block bodies B that are thermocompression bonded to both sides of the film coverlay 10 and can be handled as independent individual members are manufactured one after another.

As shown in FIG.
, and after setting a predetermined number of blocks B to be pressed, press processing is performed using hot plates 6 and 7, and then, by cutting the thermocompression bonded part made of adhesive layer 12 and adhesive 18, both The release cushion films 21 and 22 are removed. In this step, extremely soft and thin release cushion films 21 and 22 are bonded to the press-bonded block B.
Since the cushioning material 8 can be handled in an integrated state, even one operator can easily insert the cushioning material 8 between the cushioning materials 8.

[0016]

As described above, according to the method for manufacturing a flexible printed wiring board of the present invention, since the film coverlay is conveyed under tension in an uncut long length, future peeling of the protective sheet material is prevented. Work can be automated. In addition, since the film coverlay from which the protective sheet material has been peeled off is transferred under tension in the longitudinal direction, the film coverlay can be held stably even though the material is not stiff, so the position of the film coverlay is This makes it extremely easy to attach flexible printed circuit boards, and it also cuts and separates flexible printed circuit boards made of stiff material into appropriate sizes and attaches them to the film coverlay. So,
It becomes possible to automate the positioning and attachment work of the film coverlay and the flexible printed circuit board. Furthermore, since the release cushion film can be handled in a state where it is integrated with the press-bonded block, even one operator can easily insert the release cushion film between the cushion materials.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a step of peeling off a protective sheet material and a step of adhering a circuit board and a film coverlay according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the process of attaching a release cushion film to both sides of a film coverlay.

FIG. 3 is a cross-sectional view of the process of cutting and separating the press-bonded block bodies.

FIG. 4 is a sectional view of a pressing process for a plurality of press-bonded block bodies.

FIG. 5 is a sectional view of a film coverlay to which a protective sheet material is attached.

FIG. 6 is a cross-sectional view of a step of attaching a circuit board and a film coverlay in a conventional manufacturing method.

FIG. 7 is a sectional view of the pressing process as well.

[Explanation of symbols]

10 Film coverlay 11 Protective sheet material 12 Adhesive layers 16a to 16c Flexible printed circuit board 18
Adhesive 21, 22 Release cushion film B Pressure bonded block

Claims (1)

[Claims] 1. A long film coverlay having a protective sheet material adhered to one side with an adhesive layer is perforated at predetermined locations, and then transported in the longitudinal direction under tension, and the protective sheet is The plurality of flexible printed circuit boards are guided in different directions and peeled off, and the plurality of divided flexible printed circuit boards are positioned on the stretched film coverlay and temporarily pressed by the adhesive layer, and the plurality of flexible printed circuit boards are separated on the other side of the film coverlay. Adhesive is applied to both sides of the group of flexible printed circuit boards in the transport direction, and a long release cushion film is superimposed on the flexible printed circuit board side and the film coverlay side. After bonding both the release cushion films to both sides of the film coverlay using the adhesive layer and the adhesive at the adhesion position of the adhesive, the thermocompression bonded portions are cut, and the flexible printed circuit in the adhered state is removed. Both ends of the release cushion film covering both sides of the substrate and the film coverlay are crimped to form an integrated crimped block body,
A method for manufacturing a flexible printed wiring board, which comprises inserting a plurality of press-bonded block bodies between cushioning materials and pressing them.