JPS5810466B2 - 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 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 metal foil into a desired pattern, and the inside surrounded by the blade is shallowly recessed to be suitable for pressing the metal foil, and the outside is suitable for punching the metal foil after punching. To easily manufacture a high-precision, high-quality punching mold using a simple method regarding a method for manufacturing a circuit pattern punching mold that is deeply depressed and has a step so that unnecessary metal foil can escape. 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. 51-3295), and has a circuit width slightly wider than the desired wiring circuit pattern as a circuit pattern photomask used for forming an etching resist. Step etching is performed using two types of photomasks: a circuit pattern negative film N and a circuit pattern positive film P having a slightly narrower circuit width.

Here, using the above two conventional photomasks N and P,
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 N (Figs. 1 and 2) having a flat circuit pattern 4, and a metal plate 5 (Fig. 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 P (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 to heat and soften the acid-resistant resin 9 and remove it.

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, a circuit pattern N has a slightly wider circuit width than the desired wiring circuit pattern, and a circuit pattern P 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 mold for printing wiring with a large area. The circuit pattern P (Fig. 5) having a slightly narrower circuit width than the desired wiring circuit pattern for forming the etching resist (8 in Fig. 7) on the flat mold was accurately positioned and centered. They must be carefully positioned so that they match, and considerable skill is required on the metal plate.
The shape of the cutting edge depends on how the position of P is aligned, and even if there is a deviation of several tens of microns, the required cutting edge of the mold (11 in Figure 9) will be unbalanced on the left and right, and the cutting edge on one side will be relatively thick. However, the cutting edge on one side tends to be very thin, making it extremely difficult to obtain a mold of desired quality.

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, the above-mentioned drawbacks of the conventional circuit pattern punching mold manufacturing method are improved, and a consistently high-quality mold can be easily obtained. The embodiment will be explained using the drawings.

First, the novel pattern-shaped photomask used in the present invention has border lines for forming mold blades at the edges of a desired circuit pattern created from a single original drawing (trace drawing) using ordinary photographic technology. edging pattern photomask A3 (FIG. 14).

(Fig. 15) and cover pattern photomask A4 (Fig. 16, 1) made to cover this border pattern.
The shape of the photomask according to the present invention will be explained in detail below.

For example, as shown in FIG. 24, the desired circuit width is a(
It has been experimentally confirmed that metal foil can be cut by the outside of the blade.

), the width of the blade 27 is V, and the shallow groove 2 for pressing the metal foil
A case will be described in which a mold 26 having a blade suitable for punching out a desired pattern from a metal foil having a depth d and a deep groove 29 for letting the metal foil escape will be described.

In the combination of two types of photomasks, in the first embodiment, one photomask has an edging pattern photomask A3 (for forming a shallow groove 28 for pressing the blade part 27 and the metal foil). 14 and 15).

This photomask A3 has an edging line corresponding to a desired pattern, and in terms of the dimensional relationship in this case, =a1 on the inside of the edging line is from the desired circuit width a to the width 2 of the mold blade. 2 multiplied by the amount of side etching when shallowly etching (depth d) suitable for pressing the metal foil (2d/E, F, where E, F is the amount of side etching when etching the metal plate) The etch factor is E, F, which is expressed as 2d/b, assuming that when etching is performed to a depth d, side etching is performed by a distance b from the resist image area.

The outer width a2 of the border line is the amount of side etching when etching is deep enough to allow the metal foil punched to the desired circuit width a to escape. It is equal to the sum of (2D/E, F,).

When these relationships are expressed by formulas according to FIGS. 15 and 24, a,=a-2(v+d/E,F,) a2=a+2D/E,F- (where D>d).

The other photomask is a cover pattern photomask A4 (FIGS. 16 and 17) for forming deep grooves 29 for allowing the metal foil to escape.

This photomask A4 has a pattern width a3 for covering a shallowly etched portion suitable for pressing metal foil, and the pattern width a3 is smaller than the outer width a2 of the border line of the photomask A3. or equal to and greater than or equal to the inner width 31.

This relationship is expressed in the formula shown in Figures 17 and 24 as follows:
a1≦a3≦a2, that is, a-2 (v+d/E-F-)≦a3≦a+2D/E, F
, in the second embodiment, one photomask is a border pattern photomask A3 (14th, 15th
) with border lines corresponding to the desired pattern.

Regarding the dimensional relationship in this case, the inner width a1 of the edging line is the desired circuit width a, the width of the mold blade section multiplied by 2, and a shallow width suitable for pressing the metal foil. Side etching amount (2d/
E, F, ) are made equal to the closed one, and the outer width a2 of the border line is the desired circuit width a plus the side etching amount (2a/E, F,). Equally good.

When these relationships are expressed by the formulas shown in FIGS. 15 and 24, it becomes al-a2(v+d/E-F-) a2=a+2d/E,F.

The other photomask is a cover pattern photomask A4 (FIGS. 16 and 17) for forming deep grooves 29 for allowing the metal foil to escape.

This can cover the resist pattern formed by the border pattern photomask A3.

In this case, the pattern width a3 is equal to the side etch amount (2D/E, F,) added to the circuit width a when deep etching is performed so that the metal foil punched to the desired circuit width a can escape. ing.

This relationship is shown in FIGS. 17 and 24 using the formula % formula %8 Next, a method for manufacturing a mold using a photomask consisting of the above two types of combinations will be explained using the drawings as well.

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, consider drawing accuracy, dimensional tolerances, etc., decide on the magnification ratio, and enlarge the area inside the border line corresponding to the desired pattern as shown in Figure 10. An enlarged original drawing B1 on which the pattern 12 is drawn is created.

Next, this enlarged original drawing B1 is reduced to the original size using an ordinary photolithography camera, and the width is changed to the inner width a1 (a
A negative film A1 having a circuit pattern 13 in which 1=a-2(v+d/E,F-)) is created.

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 18 as shown in Fig. 18, and place the original 19 (the original size A negative film A1) as shown in FIG.
Expose at 1.

When a negative-negative (positive-positive) type photographic film, for example Kodak Super Speed Duplicating Film No. 2551, is used as the unexposed film 18,
As shown in FIG. 19, by changing the exposure amount (exposure time), the original amount of diffusion changes, and the line width of the original 19 can be increased to a desired line width.

This has been confirmed from the results of experiments.

Therefore, the negative film A1 shown in FIG. 11 was mounted as the original 19, and the exposure time was adjusted to the amount of thickening shown in FIGS. 14 and 15.
By exposing a negative-negative type unexposed film 18 for a time corresponding to al, developing, fixing, and washing with water, a negative film A having a slightly thicker circuit pattern (14 in FIG. 12) is obtained.
Get 2.

On the other hand, a positive film B2 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. 18, a negative-negative type photographic film (for example, Kodak Sufilm 2551) is used as the unexposed film 18, and the positive film of FIG. B2 and the negative film A2 shown in FIG. 12 are stacked and brought into close contact with each other, exposed to appropriate light, developed, fixed, and washed with water to form a circuit pattern (No. 14 A negative film A3 having 16) in the figure is created.

Next, using a vacuum printing frame or the like, place a negative-negative type photographic film as the unexposed film 18 as shown in FIG. 18, and place the negative film A1 shown in FIG. The exposure time is set to the area (a) for shallowly etching the metal foil to make it suitable for pressing.
The first
Refer to Figure 8 and make your selection.

After exposure, development, fixing, and washing are performed to produce a negative film A4 having a cover pattern (17 in FIG. 16) having a desired circuit pattern shape.

(b) Etching process Conventionally, an etching resist is formed using a first mask,
After deep etching, an acid-resistant resin is installed and filled to create a flat surface at the same height as the unetched area, and after further etching with a second mask, the acid-resistant resin is heated and softened again. This has the disadvantage of complicating the process.

When using a photomask as described above, it is of course possible to use an acid-resistant resin as described above, but it is also possible to use two types of photoresists with different properties, an organic solvent-based type and a water-soluble type, as an etching resist. The process can be simplified by using

Therefore, in this embodiment, a case will be described in which two types of photoresists are used, such as the latter.

As shown in FIG. 20, an organic solvent-based photoresist (for example, Tokyo Ohka Industrial TPR, Kodak KPR
A circuit pattern photomask (negative film) A3 (Fig. 14) consisting of the border of the desired circuit pattern is placed on top of it as a photomask having a pattern for shallow etching, After irradiating it with ultraviolet light (metal halide lamp, etc.) from above, it is developed, washed with water, and post-baked.

Next, a water-soluble photoresist (for example, FCR-7 manufactured by Fuji Pharmaceutical Co., Ltd.) is applied as a second etching resist 24 thereon.
The cover pattern photomask A4 (negative film) A4 is used as a photomask having a pattern to be applied and baked with a wheeler and deeply etched thereon.
(FIG. 16) is placed so as to overlap the pattern of the first etching resist 23, and after irradiating ultraviolet rays (metal halide lamp or the like) from above, it is developed, washed with water, and post-baked.

As a result, etching resists 23 and 24 consisting of two layers, first and second, are formed on the metal original plate 22.

The first etching resist 23 (
The metal original plate 22 on which the organic solvent-based photoresist TPR) and the second etching resist 24 (photoresist FCR-7) were formed was etched at 35 to 35 as the first etching process.
When deeply etched with 42°Be' ferric chloride solution, the result is as shown in FIG.

Since the portion etched at this time will also be etched during the second etching, the etching should be done shallower.

After the first etching is completed, remove the remover (5-10%
As shown in FIG. 22, the second etching resist 24 is removed using an aqueous sodium hydroxide solution.

Next, the metal plate 25 obtained in this manner is etched a second time to be shallower as shown in FIG.

Thereafter, the first etching resist 23 is removed using a stripping solution (TPR).
Peel it off using a special stripping solution.

In this way, a mold 26 having a blade 27 is manufactured as shown in FIG. 24.

Also, a border pattern photomask (Fig. 14).

By changing the width of (a2-al) of the negative film A3) in Figure 15, circuit pattern punching dies for printed wiring with blunt blades, sharp blades, and even sharper blades are manufactured. be done.

As is clear from the above description, the edging pattern photomask A3, which is one of the two types of photomasks that play an important role in the present invention, has an edging line (a2-al) for forming the cutting edge of the mold. Because it is formed with high accuracy using a photo-register punch pin alignment method, the tolerance for pattern positioning is widened, and etching resist can be formed more easily and accurately, resulting in consistently high quality. The mold can be obtained and the effect is extremely dog.

[Brief explanation of drawings]

Figures 1 to 9 are diagrams for explaining the conventional manufacturing method of manufacturing a mold using a conventional photomask. 3 and 4 are cross-sectional views showing the procedure for obtaining the negative film circuit pattern shown in FIGS. 1 and 2 on a metal original plate by etching. 5 and 6 are respectively a plan view and a cross-sectional view of a positive film having a circuit pattern slightly narrower than the desired wiring circuit pattern,
7 to 9 are cross-sectional views showing the steps of etching the metal plate shown in FIG. 4 to manufacture a mold having a blade-shaped circuit pattern, and FIGS. 10 to 24 are cross-sectional views showing the steps for carrying out the present invention. 10, 11, 12, and 13 are photographs for manufacturing molds used in the embodiments of the present invention. Plan view for explaining the mask creation procedure, 1st
4 and 15 are a plan view and a cross-sectional view of one side of the same photomask, and FIG. 16, respectively. Fig. 17 is a plan view and a cross-sectional view of the other side of the photomask, Fig. 18 is a diagram for explaining the apparatus used when making the photomask, and Fig. 19 is a diagram showing the exposure time and the time in the above-mentioned apparatus. A curve diagram showing the relationship between line width and thickening amount, and FIGS. 20 to 24 are cross-sectional views showing the steps for etching a metal original plate using the same photomask and manufacturing a mold having a blade-shaped circuit pattern. It is a diagram. 13.15... Pattern reduced to the original size from the enlarged trace diagram, 14... Circuit pattern slightly thicker than the original size circuit pattern, 22... Metal original plate, 23° 24...
・Etching resist, 26... Mold, 27... Blade mold, 28... Shallow groove for pressing metal foil, 29.
...Deep groove for letting the metal foil escape, A3...Edging pattern photomask (negative film), A4...Pattern photomask for cover (negative film).

Claims (1)

[Claims] 1. In a method for manufacturing a circuit pattern punching die having a loop-shaped blade corresponding to the peripheral shape of a circuit pattern to be punched, the inside of the blade is shallowly recessed and the outside thereof is deeply recessed, the blade of the mold is A first step of providing an etching resist on a metal plate in a manner corresponding to the pattern of the blade using a first photomask having an edging line for forming a pattern, and a step of forming an etching resist so as to cover the edging pattern of the first photomask. a second step of overlaying a second photomask having a pattern on the etching resist to form an etching resist for forming a deeply recessed portion of the mold; a third step of forming a deeply depressed portion of the mold by deeply etching the metal plate; a fourth step of peeling off the etching resist formed in the second step on the surface of the metal plate thus obtained; A fifth step of forming a shallowly depressed portion of the mold by shallowly etching the metal plate provided with the etching resist in the first step; The etching resist used in the first step and the etching resist used in the second step have two types of etching resists with different properties: organic solvent-based and water-soluble. As for the parts corresponding to the blades facing the respective patterns of the first photomask and the second photomask, the inside of the pattern of the first photomask is cut out, and the inside part corresponding to the inside edge of each of the facing blades is shaped. The width between the border lines is 2 times the width of the blade from the desired circuit width.
equal to the product multiplied by the amount of side etching when shallowly etched in the fifth step, and also the outer side corresponding to each outer edge of the opposing blade that shapes the outer side of the pattern of the first photomask. The convergence between the border lines is not wider than the desired circuit width plus the amount of side etch when etched deeply in the third step, and the amount of side etch when the desired circuit width is shallowly etched in the fifth step. , and the edge between the lines forming the pattern of the second photomask at opposing parts is not narrower than the width between the inner border lines of the corresponding part of the pattern of the first photomask. , and the width of the circuit pattern is not wider than the desired pattern width plus the amount of side etching when deeply etched in the third step.