JPS60196343A - Precise external-form cutting method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for precisely cutting a resin film-copper laminate conductor circuit board, etc., and more particularly to a method for precisely cutting a resin film into predetermined dimensions and shapes by etching.

Conventionally, methods for precision cutting of conductor circuit boards, etc.
A press punching method using a mold, a method of stamping with a router machine (a cutting machine equipped with a microcomputer that can cut a film or metal plate into any shape by moving the drill in the X and Y directions), or Laser processing methods and the like are known.

However, in the press punching method using a die, the production cost of the die is high, and the processing accuracy of the product is only about ±100μ01, which is not satisfactory. Furthermore, since it cannot be processed unless the product is of a certain size, there are restrictions on the shape, making it unsuitable for processing small-lot products. Router machine d also has a poor processing accuracy of about ±100 μm, and cannot process products unless they are of a certain size.

This also has the disadvantage of being embarrassing. moreover,
The laser method requires expensive equipment and is not suitable for processing resin films, especially polyimide films, because the cut surface is poor.

As mentioned above, the conventional methods each have various drawbacks, and the current situation is that they are not fully satisfied in terms of accuracy.

The present invention has been made in order to eliminate the drawbacks of the prior art described above, and an object of the present invention is to provide a precision contour cutting method for cutting the size and shape of a conductor circuit board, etc. with high precision.

As a result of intensive research in accordance with the above objectives, the present inventors discovered that the above objectives could be achieved by the following method and arrived at the present invention.

That is, the present invention is a precision contour cutting method for manufacturing a conductor circuit board from a resin film-copper laminate, in which the copper layer is also etched at the contour of the contour cut during the copper layer etching process to form the conductor circuit. This is a precision contour cutting method characterized in that the resin film is left to remain, and then the resin film is etched along the contour of the contour cut.

A detailed description will be given below based on the drawings.

FIGS. 1(a) to 1(d) are seven views showing one example of the culm of the precision external cutting method of the present invention over time.

First, as shown in FIG. 1(a), a copper foil 3 is laminated on one side of a resin film 1 with an adhesive layer 2 interposed therebetween. In this case, it may be directly attached by vapor deposition, sputtering, etc. without intervening an adhesive layer.

Further, since the resin film used in the present invention needs to be etched as described later, an etchingable resin film is used. Examples of the etchingable resin include polyimide, polyamide, polyamideimide, etc., and polyimide is particularly preferably used.

Next, a resist layer 1 is deposited on the copper foil 3, exposed and developed to form a resist layer, and then the copper foil is etched to form a conductive circuit as shown in FIGS. 1(b) and 1(b'). 4 a
3 and a contour section 5 for external cutting. Here, FIG. 1(b') does not show the plan view of FIG. 1(b).

Next, the resin film 1 of the etched conductor circuit board is
A resist is attached to the side, and the area directly above the contour section 5 of the outer shape cutting is exposed and developed to form a resist layer 6 having a contour corresponding to the contour section 5 of the outer shape cutting, and then the resin film 1 is etched. . That is, after forming the resist layer 6 as shown in FIG. 1(b), the outer shape of the substrate is removed by etching to remove the Y portion (the portion removed by etching) as shown in FIG. 1(c). make an amputation. When etching this resin film, if there is an adhesive layer, the surface on the conductor circuit side is usually masked by this adhesive, but if there is no adhesive layer, it is necessary to mask it to prevent it from being etched. . Further, it is preferable that the contours of the registers 21 to layer G corresponding to the contour portion 5 of the outer shape cutting are slightly smaller than the contour portion 5 of the outer shape cutting. This is to make it easier to remove the adhesive layer around the part where the resin film has been pinched, and to improve the finished appearance. Therefore, the contour section 5 of the external shape cut is
The external shape will be determined, and the cutting accuracy will be determined by the positioning and accuracy of the pattern mask in the etching process of the copper layer and the accuracy of one-cutting the copper layer. Further, when the resin film is a polyimide film, an aqueous solution of an alkali metal hydroxide or the like is used as the etching liquid.

Finally, if it has an adhesive layer, the adhesive layer is not etched with an etching solution for resin films7j
Therefore, since adhesive remains around the portion where the resin film has been etched as described above, this is removed and the -C conductor circuit board is completed and covered. This adhesive is removed by, for example, swelling and floating with a polymeric softener or the like, and then using a mechanical method such as brushing. Through the above steps, the 11th
As shown in K(d), seven parts of the adhesive are removed to complete the conductive circuit board. Therefore, regardless of whether there is an adhesive layer or not, the width A shown in FIG. 1, that is, the contour section 5 of the outer shape cut determines the outer shape.

Incidentally, in the present invention, when etching the resin film, it is optional to remove by etching not only the outline of the external cut but also a part of the resin film corresponding to a desired part of the conductor circuit. By exposing a part of the conductor circuit from the back side and not plating it,
It is possible to take out the contacts from the back side, which eliminates the need for through-hole processing (processing to create conductivity by plating inside the holes). A cross-sectional view of an example of a single-conductor circuit board made by this method is shown in FIG.

In FIG. 2, reference numeral 7 indicates a portion that has been plated with Au after being plated with a nickel base.

Furthermore, in the present invention, a pattern forming a conductor circuit, 13
Since the F-cutting pattern of the resin film can be changed arbitrarily, it is also possible to take out a part of the conductor circuit to the outside. An example of this is shown in FIG.

Hereinafter, the present invention will be explained in more detail based on Examples.

(Example) First, a 18 μm thick copper foil was laminated onto a 25 μm thick polyimide film via a 25 μm thick adhesive layer.

Next, 49 resists were applied to the copper foil, followed by exposure, development,
After etching, a series of etching operations are performed as shown in Fig. 4 (
As shown in (a) and ('b), a conductor circuit 4 consisting of 30 wiring lines and a contour portion 5 of external shape cutting were formed. A plan view of the obtained conductor circuit board is shown in FIG. 4(a).
A sectional view along J' is shown in FIG. 4(b).

Next, a resist layer 1- is attached to the polyimide film 1 side, and the area directly above the cut contour 5 is exposed and developed so that the resist layer 6 has a contour corresponding to the cut contour 5. was formed. This is shown in Figure 5. after that,
The polyimide film was cut into an outer shape by etching along the outer cut contour 5 using a polyimide etching solution.

Finally, the adhesive around the area where the polyimide film is removed is swollen with a polymeric softener, and after floating, the adhesive is completely removed by brushing, and the cut size of the tip is 6.
We have completed a flexible printed circuit board that requires 2mm±0.05ml.

As a result, the width △ is 6.2-0.02 to 6.2-0.03
It was found that the degree of cutting was less than ±30 μIll, and that a sufficiently satisfactory accuracy could be obtained.

As explained above, the present invention has the following effects.

■ Conventional methods had an accuracy limit of ±100 μm, but according to the present invention, cutting accuracy is controlled by the alignment error of the batten mask when forming the outline of the external cut and the etching accuracy of the copper layer. Therefore, the actual error is ±50
It becomes less than μm.

■ Any shape of the product can be drawn on the mask button during the etching operation, so it can handle arbitrary and complex shapes. Furthermore, cutting with a minimum width of 1 mm, which was impossible with the press method or router machine method, becomes possible.

■ There is no burr due to etching (gi'C).

■ A part of the conductor circuit can be arbitrarily taken out from the back side or end as a contact or terminal.

■ When an adhesive is used between the resin film and the conductor circuit, the beer strength (peel strength between the resin film and the copper foil) is strong and a cover coat on the surface is not required.

[Brief explanation of drawings]

1(a) to ((j) are diagrams chronologically showing a series of steps of the present invention, FIG. 2 is a cross-sectional view of a conductive circuit board obtained by an example of application of the present invention, and FIG. 3 is a diagram illustrating the present invention. A perspective view of a conductive circuit board obtained by another application example of the invention, and FIGS. 4(a), (b), and 5 are diagrams illustrating an embodiment of the present invention. 1... Resin film, 2... Adhesive layer, 3... Copper, 4... Conductor circuit, 5... Outline cutting section, 6...
... Resist, 7... Plating, X... Part from which copper was removed, Y... Part from which resin film was removed, 7... Part from which adhesive was removed. Figure 1 Figure 3 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] 1. A precision contour cutting method for manufacturing a conductor circuit board from a resin-filled copper laminate, which includes cutting the contour of the contour during etching of a copper layer to form a conductor circuit. 1. A precision contour cutting method characterized by leaving a copper layer remaining and then etching a resin film along the contour of the contour cut. 2. The precision contour cutting method according to claim 1, wherein when etching the resin film, etching is performed slightly inside the contour of the contour cut. 3. The precision contour cutting method according to claim 1 or 2, wherein when etching the resin film, a part of the resin film corresponding to a part of the conductor circuit is also etched. 4. After etching the resin film, removing the adhesive remaining around the etched area of the resin film 6' [Precision contour cutting method according to any one of claims 1 to 3].