JPH0964512A - Production of flexible circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for producing a flexible circuit board efficiently. SOLUTION: A metal foil 13 is applied to the upper surface of a base film 11 through a thermosetting or thermoplastic adhesive 12 and heated by means of a hot press 21 having a notch 21a at the end of heating plane thus bonding the metal foil 13 temporarily to the base film 11. In this regard, the metal foil 13 is not bonded to the base film 11 at an unheated part corresponding to the notch 21a. Subsequently, only the metal foil 13 is cut off by means of a punching die (stamping die) 22 and the unnecessary part of metal foil 13 is removed from the unheated part before a coverlay film 15 applied with a thermosetting or thermoplastic adhesive 16 is superposed on the entire surface thereof. Finally, the metal foil 13 is bonded to the base film 11 together with the coverlay film 15 by means of a hot press 23.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is to cut a metal foil attached on a base film into a predetermined pattern,
The present invention relates to a method for manufacturing a flexible circuit board in which a cover lay ferm is bonded over the entire upper surface.

[0002]

2. Description of the Related Art A flexible circuit board (Flexible) having a predetermined pattern used for wiring of electric components of an automobile.
A method for manufacturing a printed circuit (FPC) is disclosed in, for example, Japanese Patent Laid-Open No. 6-268354, and specifically, it is manufactured as follows.

First, as shown in FIG. 6 (a), a base film 51 is bonded via a thermosetting or thermoplastic adhesive 52.
A metal foil 53 is laid on the upper surface of the metal foil 53, and the entire surface of the metal foil 53 is heated by a heat press 61 as shown in FIG.
The metal foil 53 is temporarily fixed to the base film 51 by applying pressure.

Next, as shown in FIG. 1C, for example, after only the metal foil 53 is cut into a predetermined circuit pattern by a punching die (die stamp die) 62 having a Thomson blade 62a, the same figure ( As shown in d), the unnecessary portion of the metal foil 53 temporarily fixed on the base film 51 is peeled off.

Then, as shown in FIG. 3E, a coverlay film 55 coated with a thermosetting or thermoplastic adhesive 56 is superposed on the upper surfaces of the base film 51 and the remaining metal foil 53. The metal foil 53 is permanently fixed to the base film 51 together with the coverlay film 55 by the heat press 63. Finally, as shown in (f) of the same figure, a flexible circuit board is completed by cutting this into a desired shape.

[0006]

By the way, in the method of manufacturing a flexible circuit board as described above, since the metal foil 53 is temporarily fixed on the entire area of the base film 51, only the metal foil 53 is formed by the punching die 62. After cutting into a predetermined circuit pattern, when the unnecessary portion of the metal foil 53 starts to be peeled, or when the unnecessary portion of the metal foil 53 that has once peeled is cut and the peeling starts again, the peeling start portion is secured. It was difficult to perform the peeling work smoothly.

For this reason, the line speed of the manufacturing line cannot be increased, and in some cases, the manufacturing line must be stopped, which causes a problem that the flexible circuit board cannot be manufactured efficiently. there were.

[0008] Therefore, an object of the present invention is to provide a method of manufacturing a flexible circuit board which can efficiently manufacture the flexible circuit board.

[0009]

In order to solve the above-mentioned problems, the present invention relates to a method in which the metal foil is superposed on the upper surface of a base film via a thermosetting or thermoplastic adhesive, and then the metal foil is laminated. By temporarily fixing the metal foil and the base film by heating, to remove the metal foil of unnecessary portions by cutting only the metal foil by a punching die having a blade of a predetermined pattern, the base film and the metal In a method for manufacturing a flexible circuit board, which comprises fixing a cover lay film over the entire upper surface of a foil, and then finally fixing the cover foil by heating and pressing the metal foil, when the metal foil and the base film are temporarily fixed to each other, Therefore, an unheated area is formed at the end of the unnecessary portion.

Specifically, by heating the metal foil with a hot press in which a part of the heating surface is cut out, an unheated region can be formed at the end of the metal foil.

[0011]

Embodiments will be described below with reference to the drawings. As shown in FIG. 1A, a thermosetting adhesive 12 based on polyimide resin, epoxy resin or the like or a thermoplastic adhesive 12 based on polyester resin, acrylic resin or the like is applied to the lower surface of the base film 11. A metal foil 13 such as a copper foil is overlaid.

Next, as shown in FIG. 1B, the base film 11 and the metal foil 13 are temporarily fixed to each other by the hot press 21 having a notch 21a at the end of the heating surface to bond the bonded substrate 1 together.
4 is formed. At this time, the notch 2 of the heat press 21
Since the portion of the metal foil 13 corresponding to 1a is not heated, an unfixed region R is formed at the end of the bonded substrate 14.

Then, as shown in FIG. 3C, for example, a punching die (die stamping die) 22 having a Thomson blade 22a is pressed from above the bonding substrate 14 to control the stroke of the punching die 22. Metal foil 13 and adhesive 1
After cutting only 2, the metal foil is formed so that only the metal foil 13 having a predetermined circuit pattern is left from the unfixed region R formed at the end of the bonded substrate 14, as shown in FIG. 13 and the unnecessary portion of the adhesive 12 are peeled off ((e) in the figure)
reference). Thus, the unfixed region R of the bonding substrate 14 is
The unnecessary portion of the metal foil 13 can be easily peeled from the metal foil 13, and when the metal foil 13 is cut during peeling due to some factor, it can be peeled from another unfixed region R. It is possible to smoothly perform the peeling work of the unnecessary portion of 13. Therefore, the unfixed region R is preferably provided not only in one place but in a plurality of places. For example, it is desirable to form the unfixed region R over the entire circumference of the bonding substrate 14.

Next, as shown in FIG. 1F, a coverlay film 15 coated with a thermosetting or thermoplastic adhesive 16 is superposed on the upper surfaces of the base film 11 and the metal foil 13, and the upper surfaces thereof are stacked. By heating and pressing the whole with a heat press 23, the metal foil 13 is permanently fixed to the base film 11 together with the cover lay film 15. The coverlay film 11 may be perforated beforehand if necessary.

Finally, as shown in FIG. 3G, an FPC having a predetermined pattern is completed by cutting into a desired outer shape by a press or the like.

As described above, the unfixed region R is formed at the end of the bonded substrate 14 to which the base film 11 and the metal foil 13 are temporarily fixed, so that the work of removing the unnecessary portion of the metal foil 13 can be performed smoothly. Therefore, the line speed of the production line can be made faster than before, and since the production line is not stopped, the productivity is improved. Furthermore, since the peeling process of the metal foil 13 can be automated, it is possible to reduce the cost of the product.

2 to 4 show another embodiment. The difference between this embodiment and the above embodiment is that instead of the heat presses 21 and 23, heat rollers 31 and 33 are used.
A rotary type punching die 32 is used instead of the flat plate type punching die 22.

The manufacturing process of the FPC in this embodiment will be outlined below. First, the base film 11 and the metal foil 13 delivered from the roll A and the roll B, respectively.
After the adhesive 12 is applied to the metal foil 13 side on the way,
As shown in FIG. 3A, the base film 11 and the metal foil 13 are tentatively fixed to each other by being superposed on each other and being sandwiched by the heat roller 31 and heated. This heat roller 31
Is a heating surface 3 that contacts the metal foil 13, as shown in FIG.
The width of 1a is shorter than the width of the metal foil 13, and the unfixed region R that is not heated is continuously formed on one side of the metal foil 13.

Then, as shown in FIG. 3B, the blade 32
The metal foil 13 is cut by a rotary type punching die 32 having a and unnecessary portions are peeled off,
As shown in FIG. 3C, the metal foil 13 forms a circuit pattern on the base film 11. In this peeling step, since the unfixed region R is continuously formed on one side of the metal foil 13, the unnecessary portion of the metal foil 13 can be easily peeled from the unbonded region R as in the above embodiment. can do.

On the other hand, the cover lay film 15 delivered from the roll C is perforated by the punching 34 and then coated with the adhesive 16 to be superposed on the base film 11. In this way, the base film 11 on which the cover lay film 15 is overlapped
As shown in FIG. 3D, the metal foil 13 is permanently fixed to the base film 11 together with the cover lay film 15 by being sandwiched by the heat roller 33 and heated, and then cut into a predetermined shape by punching 35. As a result, a product (FPC) as shown in FIG. The cutting waste is wound up on the roll D.

In this embodiment, as described above, by making the heating surface 31a of the heat roller 31 shorter than the width of the metal foil 13, the unfixed region R is continuously formed on one side of the metal foil 13. Although the heating surface 31a is set to have the same length as the width of the metal foil 13 and a partial cutout 31b is formed at its end as shown in FIG. You may make it form an unfixed area | region continuously at a fixed space | interval.

In each of the above-described embodiments, the unfixed region R is formed at the peripheral edge of the entire metal foil 13 that is temporarily fixed on the base film 11.
Need only be present at the peripheral edge of the unnecessary portion of the cut metal foil 13, so if the unfixed region R is formed at the peripheral edge of such an unnecessary portion, the unfixed region R is a metal. It does not matter if it is located in the central portion of the entire foil 13.

[0023]

As described above, in the method for manufacturing a flexible circuit board of the present invention, when the metal foil is temporarily fixed on the base film, the unheated region is formed at the end of the metal foil. An unfixed region is formed corresponding to the unheated region, and the unnecessary portion of the metal foil can be easily peeled from the unfixed region, so that the peeling operation can be performed smoothly.

As a result, the line speed of the production line can be made faster than before, and the production line is not stopped, so that the productivity is improved. Furthermore, since the peeling process of the metal foil can be automated,
It is also possible to reduce the cost of the product.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of an FPC in an embodiment of a method for manufacturing a flexible circuit board of the present invention.

FIG. 2 is a schematic view showing an FPC manufacturing apparatus in another embodiment.

FIG. 3 is an operation explanatory diagram of the above.

FIG. 4 is a view showing a heating roll of the above.

FIG. 5 is a view showing another embodiment of the above heating roll.

FIG. 6 is a manufacturing process diagram of a conventional flexible circuit board.

[Explanation of symbols]

 11 Base Film 12 Adhesive 13 Metal Foil 15 Coverlay Film 16 Adhesive 21, 23 Heat Press 21a Notch 22,22 Punching Die 22a, 32a Blade 31, 33 Heat Roller 31a Heating Surface 31b Notch 34, 35 Punching A, B, C, D, Roll R Unfixed area

Claims (2)

[Claims] 1. After superposing the metal foil on the upper surface of a base film via a thermosetting or thermoplastic adhesive,
The metal foil and the base film are temporarily fixed by heating the metal foil, and the metal foil alone is removed by cutting only the metal foil with a punching die having a blade of a predetermined pattern, and the base is removed. In the method of manufacturing a flexible circuit board in which the cover foil is superposed on the entire upper surfaces of the film and the metal foil, and then the whole is heated and pressed, the metal foil and the base film are temporarily fixed. A method for manufacturing a flexible circuit board, wherein an unheated region is formed at an end of an unnecessary portion of the metal foil. 2. A non-heated region is formed at an end of an unnecessary portion of the metal foil by heating the metal foil with a hot press in which a part of a heating surface is cut out.
A method of manufacturing the flexible circuit board according to claim 1.