JPS5810467B2 - Manufacturing method for circuit pattern punching mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a circuit pattern punching die having a blade die suitable for punching out a circuit pattern from metal foil, which is used for manufacturing printed wiring boards by the die stamp method, for example. It is equipped with a blade suitable for punching the metal foil into a desired pattern, and the inside surrounded by the blade is shallowly recessed so as to be suitable for pressing the metal foil, and the outside is hollow Regarding the manufacturing method of a circuit pattern punching mold that is deeply recessed and has a step so that unnecessary metal foil can escape, it is possible to easily manufacture a punching mold with high precision and high quality using a simple method. The purpose is to

Conventionally, the etching technology that creates a step between the inside and outside of the blade mold as described above is a blade suitable for punching circuit patterns from metal foil onto organic insulating substrates that serve as the base of printed wiring boards. A method of manufacturing a circuit pattern punching die having a mold (for example, Japanese Patent Publication No. 50-32651, Japanese Patent Application Laid-open No. 4
8-1864, JP-A No. 51-32959), and has a circuit width slightly wider than the desired wiring circuit pattern as a circuit pattern photomask used in the shape of an etching resist. Step etching is performed using two types of photomasks: a circuit pattern negative film A and a circuit pattern positive film B having a slightly narrower circuit width.

Here, using the above two conventional photomasks A and B,
A part of the manufacturing process of a mold having a blade type as described above is explained in the first step.
This will be briefly explained using FIGS.

Circuit pattern 1 slightly wider than the desired wiring circuit pattern
An etching resist 2 (FIG. 3) is formed on the metal original plate 3 using a negative film A (FIGS. 1 and 2) having a flat circuit pattern 4. ) is manufactured, and then the concave portion 6 of the metal plate 5 is manufactured.
is filled with acid-resistant resin 9 made of, for example, epoxy resin as shown in FIG.

Next, using a positive film B (FIGS. 5 and 6) having a circuit pattern 7 slightly narrower than the desired wiring circuit pattern, an etching resist 8 is formed as shown in FIG. As shown in the figure, shallow etching is performed, and the acid-resistant resin 9 is softened and removed by heating.

In this way, a mold 10 (FIG. 9) having a blade 11 is manufactured.

Here, the important points in the manufacturing process of a mold with a blade are:
There are two types of photomasks for forming an etching resist, and as shown in this conventional example, circuit pattern A has a slightly wider circuit width than the desired wiring circuit pattern, and circuit pattern B has a slightly narrower circuit width than the desired wiring circuit pattern. Tono 2
In the case of a seed photomask, during the photoresist formation process after resin filling in the mold manufacturing process, this is especially true when manufacturing a large area printed wiring mold, but the first etching process The circuit pattern B (Fig. 5), which has a slightly narrower circuit width than the desired wiring circuit pattern for forming the etching resist (8 in Fig. 7), is accurately positioned and centered on the flat mold. They must be carefully positioned so that they match, and considerable skill is required on the metal plate, and these two types of photomasks A
.

The shape of the cutting edge depends on how the position of B is aligned, and even if there is a deviation of several tens of microns, the cutting edge of the mold (11 in Figure 9) is required.
It was extremely difficult to obtain a mold of desired quality, as the left and right sides were unbalanced, and the cutting edge on one side was relatively thick while the cutting edge on the other side was very thin.

The present invention is a novel method that allows easy formation of the etching resist pattern necessary to form a desired circuit pattern on the surface of a metal plate, and also enables quick alignment of a circuit pattern photomask. By using a pattern-shaped photomask, we aim to improve the above-mentioned drawbacks of the conventional manufacturing method of circuit pattern punching molds and make it easier to obtain consistently high-quality molds. , Examples thereof will be described below with reference to the drawings.

First, the novel pattern-shaped photomask used in the present invention is a patterned photomask B3 (No. Figure 16, 17
It is a combination of two types of photomasks: pattern photomask A4 (Figures 18 and 19) having a slightly wider circuit width than the circuit width of the desired circuit pattern, and the photomask will be referred to below as a combination of two types of photomasks: The shape of will be explained in detail.

For example, as shown in FIG. 28, the desired circuit width is a (it has been experimentally confirmed that the metal foil can be cut on the outside of the blade).

), the width of the blade 33 is V, the depth of the shallow groove 27 for pressing the metal foil is d, and the deep groove 31 for letting the metal foil escape is D. Punching the metal foil into a desired pattern. When manufacturing a mold (FIG. 28) having a blade mold suitable for the above, one of the photomasks has a contoured pattern 18 for forming a shallow groove 27 for pressing the blade mold 33 and the metal foil. 16 and 17).

This photomask B3 is obtained by multiplying the circuit width a of the desired pattern by 2 by the width V of the mold blade, and by shallowly etching (depth d) suitable for pressing the metal foil. Side etch amount (2d/E, F, where E and F are etch factors when etching a metal plate, and when etching is done to a depth d, side etching is performed by a distance b from the resist image area. Then, E, F, -
2d/b) minus the width a;
The pattern has an outline 41 corresponding to the desired pattern shape.

The inner width a2 of this contour line 41 is equal to the width a of the desired pattern plus the side etch amount (2d/E, F,) when shallowly etched.

Further, =a3 outside the contour line 41 is the side etching amount 2D/E when deeply etched (depth D) to the circuit width a,
It is equal to F minus the amount of side etching when shallowly etched (depth d).

These relationships are expressed by formulas as shown in FIGS. 17 and 28: a1=a-(2v+2d/E, F,) a2=a+2d/E, F.

a3=a+2(D-d)/E, F, (where D>d).

Next, the other photomask is photomask A4 (FIGS. 18 and 19) having a slightly wider pattern 19 for forming deep grooves 31 for letting the metal foil escape.

This photomask A4 is made so that its width a4 is wider than or equal to the circuit width a of the desired circuit pattern, and the side etch amount ( This relationship is made to be narrower than or equal to the sum of 2D/E, F,), and can be expressed as an equation according to FIGS. 19 and 28 as follows: a≦a4≦a+2D/E,F.

becomes.

Next, a manufacturing method for manufacturing a mold using the two types of photomasks as described above will be described with reference to the drawings.

The explanation will be divided into two parts: (a) camera work process and (b) etching process.

(B) Camera work process First, in order to reduce drawing errors, the magnification ratio is determined by considering drawing accuracy, dimensional tolerances, etc. As shown in Fig. 10, in Figs. An enlarged original drawing in which pattern 12 is drawn is created by enlarging the inner part (that is, the part whose width is 32).

Next, this enlarged original drawing was reduced to the original size using an ordinary photoengraving camera, and the width was 32 (a2 = a - 2d / E) as shown in Figure 11.
, F) Negative film A1 having the pattern 13
Create.

Next, using a vacuum printing frame with glass for ordinary photolithography or a contact printing frame with pressure applied by a spring, place the unexposed film 20 as shown in Figure 20, and place the original 21 (the original size A negative film A1) as shown in FIG.
Expose at 3.

When a negative-negative (positive-positive) type photographic film, for example Kodak Super Speed Duplicating Film No. 2551, is used as the unexposed film 20, the exposure amount (exposure time) is changed as shown by curve N in FIG. As a result, the original amount of diffusion changes, and the line width of the original 21 can be increased to a desired line width.

This has been confirmed from experimental results.

Therefore, the negative film A1 shown in FIG. 11 was mounted as the original 21, and the exposure time was such that the amount of thickening was as shown in FIG. 16.

A negative-negative type unexposed film 20 is exposed for a time corresponding to (a3-a2) in FIG. 17, and after developing, fixing, and washing, a negative film A2 having a slightly thicker circuit pattern (14 in FIG. 12) is formed. obtain.

On the other hand, a positive film B1 having a circuit pattern (15 in FIG. 13) having the same size as the circuit pattern 13 of the negative film A1 is prepared by applying proper exposure to the negative film A1 shown in FIG. 11 and inverting the negative film A1.

Next, in FIG. 20, a positive type photographic film (for example, Kodak Risfilm No. 255) is used as the unexposed film 20, and the positive film B1 shown in FIG. When the glasses 22 are stacked and brought into close contact with each other and exposed from above with a point source 23,
As shown by curve P in FIG. 21, by changing the exposure amount (exposure time), the original amount of diffusion changes, and the line width of the original 21 can be narrowed to a desired line width.

Therefore, after exposing, developing, fixing, and washing with water for an exposure time corresponding to the amount of thinning (a2-al) in FIG. 17, positive film B2 having a slightly thinned circuit pattern (16 in FIG. 14) was obtain.

Further, from this positive film B2, a negative film A3 having a circuit pattern (17 in FIG. 15) having the same size as the circuit pattern 16 of the positive film B2 by inverting the contact with proper exposure.
Next, as shown in FIG. 20, a negative-positive type photographic film, for example, Kodak Reproduction Film No. 2566, is used as the unexposed film 20, and as the original 21, positive film B1 in FIG. 13 is used with a slightly thicker circuit pattern. (Negative film A2 having 14: in Fig. 12)
The images are overlapped and brought into close contact to give proper exposure.

Next, using a known focusing device (not shown) using a register punch, a slightly narrower negative film A3 shown in Figure 15 is superimposed in place of the films B1 and A2 shown in Figures 13 and 12, and re-exposed. By developing, fixing, and washing with water, a positive film B3 having a circuit pattern with outlines (18 in FIGS. 16 and 17), which is an important part of the present invention, is created.

Next, using a vacuum printing frame or the like, a negative-negative type photographic film is placed as an unexposed film 20 as shown in FIG. Place the film A1, and set the exposure time to the amount that the line width of the circuit pattern covers the die of the mold (
Select and decide with reference to FIG. 21 so that a≦a4≦a+2D/E, F).

After exposure, development, fixation, and washing are performed to produce a negative film A having a circuit pattern (19 in FIGS. 18 and 19) wider than the circuit width of the desired circuit pattern.

(0) Etching process As shown in Fig. 22, the metal original plate 25 (-3
A photoresist material 24 (for example, an etching resist such as Tokyo Ohka Kogyo's TPR or Kodak's KPR) is coated and baked on a low-carbon steel (such as, for example, or a hardened material) using a hoarer, and a desired circuit is printed on it. The positive film 3 as a pattern photomask having a circuit pattern 18 with an outline provided in the pattern (FIG. 17)
After exposing the film to ultraviolet light (metal halide lamp, etc.), develop it and wash it with water.

As a result, a positive film B3 (17th
An etching resist 26 (FIG. 23) corresponding to the transparent circuit pattern shown in FIG.

Next, by shallowly etching the metal original plate 25 on which the etching resist 26 has been formed, the exposed portion of the metal original plate 25 on which the etching resist 26 is not applied is corroded and a depression is formed as shown in FIG. Part 2
7 is formed.

The etching resist 26 on the surface of the thus obtained metal plate 28 (FIG. 24) is removed using a removing solution.

This concave portion 27 is filled with an acid-resistant resin 29 made of, for example, epoxy resin so as to form a flat surface at the same height as the unetched portion, as shown in FIG.

Next, a photoresist material is applied and baked on this surface, and exposed using the negative film A4 (FIG. 19) as a pattern photomask having a circuit pattern 19 having a circuit width wider than the circuit width of the desired circuit pattern. Develop,
Wash with water and form an etching resist 30 as shown in FIG.
form.

After this, by deep etching treatment 31, the 27th
Corroded as shown in the figure.

Then, the etching resist 30 is peeled off using a stripping solution, and the acid-resistant resin 29 is further heated and softened to be removed.

In this way, a mold 27 having a blade 33 as shown in FIG. 28 is manufactured.

By changing the width (al, a2) of the contoured circuit pattern of the photomask (positive film B3 in Fig. 17), it is possible to print with a blunt edge, a sharp edge, and even a sharp edge. A circuit pattern punching die for wiring is manufactured.

As is clear from the above explanation, this is one of the two types of photomasks that play an important role in the present invention.
In the photomask B3 having a pattern with contour lines, the contour (a2-al) for forming the cutting edge of the mold is formed with high precision by photo-register punching and pin-alignment, so it is easy to position the pattern. Since the tolerances are wider and the etching resist can be formed more easily and accurately, molds of consistently high quality can be obtained, and the effect is extremely effective.

[Brief explanation of drawings]

Figures 1 to 9 are diagrams for explaining the conventional manufacturing method of manufacturing a mold using a photomask. 3 and 4 are a plan view and a cross-sectional view of Nekabu film having a wide circuit pattern; FIGS. 3 and 4 are cross-sectional views showing the procedure for obtaining the circuit pattern of the negative film shown in FIG. 6 is a plan view and a sectional view of a positive film having a circuit pattern slightly narrower than the desired wiring circuit pattern, and FIGS. 7 to 9 show the metal plate shown in FIG. 4 etched to form a blade-shaped circuit pattern. A sectional view showing a procedure for manufacturing a mold having a first
0 to 28 are diagrams for explaining a method for manufacturing a circuit pattern punching mold according to an embodiment of the present invention, and among these, FIGS. 10 to 15 are diagrams showing a mold used in an embodiment of the present invention. 16 and 17 are respectively a plan view and a cross-sectional view of one side of the same photomask, and FIGS. 18 and 19 are respectively the same photomask. A plan view and a sectional view of the other side of the photomask, FIG. 20 is a diagram for explaining the equipment used to create the same photomask, and FIG. 21 shows the exposure time and the amount of thickening and thinning of the line width in the above equipment. FIGS. 22 to 28 are cross-sectional views showing the steps for etching a metal original plate using the photomask and manufacturing a mold having a blade-shaped circuit pattern. 13.15...Pattern reduced to the original size from the enlarged trace diagram, 14...Circuit pattern slightly thicker than the original size circuit pattern, 17...Circuit pattern slightly thinner than the original size circuit pattern, 25... Metal original plate, 26.3
0... Etching resist, 32... Mold, 33...
...blade shape, 27...shallow groove for pressing metal foil,
31...Deep groove for letting the metal foil escape, B3...Circuit pattern photomask with outline (positive film), A
4...Slightly wider circuit pattern photomask (negative film).

Claims (1)

[Claims] 1. A method for manufacturing a die for punching a circuit pattern, which has a loop-shaped blade corresponding to the peripheral shape of the circuit pattern to be punched, the inner side of which is shallowly recessed, and the outer side of which is deeply recessed. a first photomask having a circuit pattern shape corresponding to the shape and having an outline line of a predetermined width along the outside of the pattern; and a second photomask having a circuit pattern slightly wider than the circuit width of the desired circuit pattern. A first step of creating two types of photomasks; a second step of forming an etching resist on a metal plate using the first photomask in a manner corresponding to the pattern of the blade; and a second step of forming an etching resist in the second step. By shallowly etching the metal strip provided with
A third step of forming a shallowly depressed part of the mold and forming a groove on the outside of the blade, and peeling off the etching resist on the surface of the metal plate obtained in this way, and etching the shallowly depressed part obtained by etching. a fourth step of filling the circuit pattern with an acid-resistant resin, a fifth step of providing an etching resist on the circuit pattern of the metal plate using a second photomask, and deeply etching the metal plate provided with the etching resist in the fifth step. As a result, the sixth step of forming the deeply depressed portion of the mold, and the seventh step of removing the etching resist of the metal plate thus obtained and the acid-resistant resin filled in the shallowly depressed portion of the metal plate. The first
Regarding the portions of the pattern of the photomask and the second photomask corresponding to the opposing blades, the inside edge of the pattern of the first photomask is shaped and corresponds to the inside edge of each of the opposing blades. The width between the lines is
It is equal to the desired circuit width multiplied by the width of the blade by 2 minus the amount of side etching when shallowly etched in the third step, and the outside of the first photomask is similarly shaped and facing The width between the outer edge lines, which correspond to each outer edge of the blade and are common to the lines that define the inside of the contour line, is the desired circuit width plus the amount of side etching when shallowly etched in the third step. The amount of side etching for both sides is equal to that, and when etching is done deeply and shallowly in the 6th and 3rd steps, respectively, so that the width between the lines of the mutually opposing parts is the desired pattern width. furthermore, the width between the lines forming the pattern of the second photomask at opposing parts is not smaller than the desired pattern width, and the sixth A method for manufacturing a circuit pattern punching die, characterized in that the amount of side etching is not greater than the sum of side etching when deeply etched in an etching process.