JPS5810990B2 - Manufacturing method for circuit pattern punching mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a circuit pattern punching die used for manufacturing printed wiring boards by a die stamping method, and particularly a blade mold suitable for punching metal foil into a circuit pattern shape. The present invention relates to a method for manufacturing a circuit pattern punching die having a circuit pattern punching die.

For example, etching is a well-known method for manufacturing circuit pattern punching dies.

Based on this method, a method for manufacturing a circuit pattern punching die having a blade shape suitable for punching a circuit pattern from metal foil onto an organic insulating substrate includes, for example, Japanese Patent Publication No. 50-3.
2651 JP 48-1864, JP 51-32
As described in No. 959, a negative film with a circuit pattern slightly wider than the desired wiring circuit pattern and a negative film with a circuit pattern slightly narrower than the desired wiring circuit pattern are used as a circuit pattern photomask used for forming an etching resist. Create a positive film and perform etching twice using these circuit pattern photomasks.
We manufacture molds with stepped blades.

A part of the conventional manufacturing process of a metal mold having a blade mold will be briefly explained using FIGS. 1 to 9.

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, and a metal plate 5 (Fig. 4), and then the concave portion 6 of the metal plate 5 is manufactured.
Acid-resistant resin 9 made of, for example, epoxy resin is filled in 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 FIG. 8, shallow etching is performed, and the acid-resistant resin 9 is softened and removed by heating.

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

There are two important points in the manufacturing process of the mold with the blade type seen in this conventional example. One is the method of creating a photomask for forming the etching resist during the mold manufacturing process. As described above, the photomasks are negative film A having a slightly wide circuit pattern and positive film B having a slightly narrow circuit pattern.

The other method is to perform etching twice using each of the 82 photomasks described in A above for forming an etching resist, and after forming an etching resist with the first mask, deep etching is performed. First, the etched area is filled with an acid-resistant resin to prevent further etching, and then an etching resist is formed using a second mask, followed by shallow etching.

Here, a method for producing the two films A and B used for forming the etching resist will be explained.

First, negative film A is prepared with the expectation that the desired circuit pattern will be etched, an enlarged original drawing (trace drawing) is drawn in order to reduce drawing errors, and then the original size (as it includes etching) is drawn using the photographic scale method. slightly wider)
Created by

Next, the procedure for producing positive film B will be described.

First, using the negative film A, an etching resist 2 is formed as shown in FIG. 3, and deeply etched by an etching method to form a mold as shown in FIG. 4.

The concave portion 6 of the metal plate 5 having the flat circuit pattern 4 is filled with a developer, and a fully exposed photographic film is placed so as to be in close contact with the surface of the flat circuit pattern 4 of the metal plate 5. A developing solution is brought into contact with the film in the recessed portion 6 .

After that, this film is fixed and washed with water to obtain a negative film in which the flat circuit pattern 4 is accurately copied.

A positive film is created from this negative film using ordinary photographic methods.

This positive film is attached to a special printing device that makes a circular vibration motion, and while the positive film is slightly shaken,
By printing photographic film, a negative film having a circuit width narrower than the desired circuit pattern width is created.

By photographically closely inverting this, a positive film B having a slightly narrower circuit pattern is produced.

Next, a second example of the method for producing the circuit pattern films A and B will be described as follows.

Negative film A was designed to be etched into the desired circuit pattern, and the cause (trace diagram) was enlarged 1.5 to 2 times in order to reduce drawing errors, and then the original size (
Since it includes etching, it is created by making the circuit pattern slightly wider than the desired circuit pattern.

Next, for positive film B, an original drawing (trace drawing) was drawn with a circuit pattern width slightly narrower than the desired circuit pattern width, enlarged by 15 to 2 times in order to reduce drawing errors, and then the photographic scaling method was used. Created by scaling to original size.

As described above, the conventional mold manufacturing method has the following drawbacks.

First, regarding the method of creating a photomask in the camera work process, when creating the negative film A and positive film B necessary for forming the etching resists 2 and 8, the first
In the example above, a process involving complicated operations (particularly a process of accurately copying the flat circuit pattern 4) and special equipment (
(a device that performs circular vibration motion), and the second
In this example, an original image (trace image) that is wider than the desired pattern width and an original image (trace image) that is narrower than the desired pattern width are drawn, and negative and positive films are created using ordinary photographic methods.

By the way, when creating a complex circuit pattern, it is extremely difficult in current artwork work to draw two original drawings (trace drawings) that are completely similar to the desired pattern, one a little wider and one a little narrower than the desired pattern. It is difficult to draw, and requires very precise drafting equipment and special considerations, such as advanced drafting techniques and a lot of time.

Next, in the etching resist forming step, in both the first and second examples, when manufacturing a mold for printing wiring with a large area, etc., the desired etching resist used when forming the etching resist 8 shown in FIG. 7 is used. Positive film B (No. 5) has a circuit pattern slightly narrower than the wiring circuit pattern of
It is very difficult to align the etching resist pattern, and the required mold cutting edge (11 in Figure 9) is unbalanced on the left and right, and one side is relatively thick. However, the cutting edge on the other side tends to be very thin.

Furthermore, in the etching process, an etching resist is formed using the first mask, and after deep etching, an acid-resistant resin is applied and filled so as to form a flat surface at the same height as the unetched areas, and then after etching, this is again etched. The process was complicated, as it had to be removed by heating and softening.

As described above, the conventional manufacturing method has at least three major drawbacks.

The present invention has been improved in order to eliminate the above-mentioned drawbacks of the conventional circuit pattern punching mold manufacturing method, and it is possible to easily manufacture stable and high-quality molds using a simpler method. The present invention provides a method for manufacturing a circuit pattern punching die.

Specifically, in the past, the first and second disadvantages are that the mask pattern creation process is complicated and requires special equipment or advanced drawing techniques, and that the pattern positioning tolerance during etching is difficult. As for the difference being small, a circuit pattern photomask (negative film) consisting of one original drawing (trace drawing) and the edges of the desired circuit pattern created using ordinary photographic techniques and the circuit width of the desired circuit pattern. A significant improvement has been made by using a patterned photomask (negative film) having a wider circuit width than the conventional one.

Regarding the third drawback, which is that the process is complicated due to the use of acid-resistant resin, the conventional etching technology was examined in detail, and the printing industry required a particularly precise dry offset plate. A plate-making method that is sometimes used is to use several types of photoresist films with different solubility in solvents, and to prevent side etching during etching by changing the printing width of each print line (Satoshi Sato).
: Metal Surface Industry Complete Book (18) Metal Etching Technology, Maki Shoten, published June 1975, P, 191-P, 194)
However, this method has been applied and improved to produce a circuit pattern photomask consisting of the edge of the desired circuit pattern described above and a pattern photomask having a circuit width wider than the width of the desired circuit pattern. We discovered a new etching method suitable for producing circuit pattern punching molds through a series of processes using a series of processes, and were able to obtain consistently consistent molds without going through complicated work processes.

This is because the dry offset plate making method used in the printing industry is used simply to form a first resist and a second resist to prevent side etching and reduce pattern width reduction. By further developing this, we improved the shape of the two mask patterns as described in the improvement of the first and second defects above, and removed the etching steps with acid-resistant resin. It is designed so that it can be done without the need for.

The photoresist used to form the etching resist will now be described.

There are two practical classification methods for photoresists:

Classification 1 includes negative-positive type (where the area exposed to light hardens through photopolymerization and becomes insoluble in the developer) and positive type (where the area exposed to light hardens due to photolysis and becomes insoluble in the developer).
(Soluble in developer) Class 2 is divided into water-soluble form and organic solvent-soluble form.

The combination of photoresists most suitable for the present invention will be explained according to this classification method.

In Category 1, positive-positive types (for example, product names such as Shipley's AZ-111, Fuji Pharmaceutical Membrane's FPPR, Eastman Kodak's KAR-3, etc.) lack flexibility due to the short molecular chain of the resin. 35 like a printed circuit board
There is no problem with etching copper foil of μm, but since the mold to be obtained with the present invention requires deep etching (300 to 600μ), with this type of resist, the resist lifted by side etching during etching may be blown away. It had the disadvantage that the etching solution applied to it would cause it to break and the side etching would proceed further.

However, negative-positive types (for example, trade names such as Tokyo Ohka Kogyo's TPR, Nonchron, G-90, Fuji Pharmaceutical Membrane FPER, FR-14, l5, FCR-7, Eastman Kodak Co., Ltd.'s KPR, KTFR1 Yoshitani Shokai) Aquaresist +100, etc.) are photopolymerized and have long molecular chains, so they are more flexible and can be etched more easily than positive types.Even if side etching occurs, the floating resist can be sprayed onto the sides without breaking due to the etching solution. If anything, it hangs down to prevent sex.

For this reason, it is more suitable than the positive type for deep etching.

In Category 2, organic solvent-based forms (for example, the product names are TPR1 manufactured by Tokyo Ohka Kogyo, FPER manufactured by Fuji Pharmaceutical, KPR and KTFR manufactured by Eastman Kodak, and AZ-1 manufactured by Shipley)
11) and water-soluble forms (e.g. Tokyo Ohka Kogyo Membrane G-90)
, Nonkron, Fuji Pharmaceutical Co., Ltd. FR-14, 15, FC
R-7, Aquaresist≠100 manufactured by Yoshitani Shokai, etc.).

In this case, if a pattern is formed using an organic solvent-based photoresist as the lower layer resist, and an organic solvent-based photoresist is also used as the upper layer resist, the lower layer resist will not have much resistance to organic solvents, so the upper layer resist will During coating, development, or peeling off after etching, the underlying resist may melt or pinholes may occur.

For example, as a negative-positive type organic solvent-based photoresist for the lower layer, Eastman Kodak Company's product name K is used.
A resist pattern is formed using TFR, and a resist pattern is formed on the upper layer using a positive type organic solvent photoresist (trade name AZ-Ill manufactured by Shipley). After the first etching, a resist pattern is formed using an organic solvent photoresist. The method of stripping with methyl ethyl ketone and performing a second etching is difficult to operate without completely damaging the KTFR resist layer (pinholes, etc.), and
It was found that deep etching (300 to 600 μm) was not possible because Z-III is a positive type.

In addition, a negative-positive type organic solvent-based photoresist is used for the lower layer resist, and a positive-positive type organic solvent-based photoresist is used for the upper layer resist, so that the lower layer resist is resistant to the stripping solution of the upper layer resist. Otherwise, after the first etching is completed, the upper layer of the positive type resist film is entirely exposed to light, made alkali soluble, and then the upper layer of resist is removed with alkali. However, this method increases the number of steps and increases the number of steps. It is a positive type and is not suitable for deep etching, and since it is originally an organic solvent type, it is difficult to operate without completely damaging the underlying resist.

Therefore, as the resist for the lower layer, a negative-positive type organic solvent type photoresist (especially polycinnamic acid type...KP
As the upper layer resist, a negative-positive type water-soluble photoresist, especially an azide type (such as FCR-7) is preferable.

Dichromate-natural colloid systems and dichromate-synthetic colloid systems (G-90, FR-14, FR-15, etc.) can also be used, but they have drawbacks in terms of pollution.

) and by combining two types of photoresists with completely different properties, the above drawbacks could be eliminated.

As described above, the present invention provides a method of simplifying the process, and easily manufacturing a mold having a uniform quality and having a stepped blade mold.

An embodiment of the present invention will be described below with reference to the drawings.

In the explanation, the process will be divided into three parts: (a) camera work process, (b) etching resist forming process, and (c) etching process.

(B) Camera work process First, in order to suppress drawing errors, an enlarged original drawing of the desired circuit pattern (trace drawing: Fig. Create 12).

A negative film A1 is produced by reducing this enlarged original drawing 12 to the original size (the size of the desired stamp wiring circuit pattern 13 considering etching) as shown in FIG. 11 using an ordinary photolithography camera.

Next, use a vacuum printing frame with glass for ordinary photolithography or a contact printing frame that applies pressure with a spring.
Place the unexposed film 18 as shown in Fig. 16, and place the original 19 on top of it (the negative film AI reduced to the original size as shown in Fig. 11).
), and a contact glass 20 is stacked and brought into close contact therewith, and exposed from above with a point light source (contact printing lamp) 21.

When a negative-negative (positive-positive) type photographic film, such as Kodak Super Speed Duplicating Film No. 2551, is used as the unexposed film 18,
As shown in FIG. 17, by changing the exposure amount (exposure time), the amount of light diffusion changes, and the line width of the original 19 can be increased to a desired line width.

This has been confirmed by actual results.

Therefore, the negative film A1 shown in FIG. 11 is mounted as the original 19, and the negative-negative type unexposed film 18 is exposed to light at a time such that the amount of thickening corresponds to the width a shown in FIG. 14. After fixing and washing with water, negative film A has a slightly thicker circuit pattern (15 in Figure 13).
Get 2.

- A positive film B1 having a circuit pattern (14 in FIG. 12) 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.

Next, as the unexposed film 18 in FIG.
Using a negative type photographic film (for example, Kodak Lisfilm A2551), stack the positive film B1 shown in FIG. 12 and the negative film A2 shown in FIG. By washing with water, a negative film A3 having a circuit pattern (16 in FIG. 14) consisting of a border of a desired circuit pattern is obtained.
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.
Place the negative film A+ shown in Figure 1, and set the exposure time so that the line width of the circuit pattern covers the blade of the mold. Refer to the diagram and make your selection.

After exposure, the film is fixed on a sheet of paper and washed with water to produce a negative film (17 in FIG. 15) having a circuit pattern wider than the circuit width of the desired circuit pattern.

(0) Etching resist forming process As shown in FIG. 18, a lower layer etching resist 23 is formed on a metal original plate 22 (low carbon steel material such as carbon tool steel, carbon steel for mechanical structures, alloy tool steel, etc., or a hardened material). A negative-positive type organic solvent type photoresist (for example, Tokyo Ohka Kogyo's TPR, Eastman Kodak's KPR, KTFR Fuji Pharmaceutical's EPER, etc.) is coated and baked in a boiler, and then shallowly etched on top. As a photomask having a pattern, a circuit pattern negative film A consisting of the border of the desired circuit pattern is used.
3 (FIG. 14), irradiation with ultraviolet rays (for example, using a high-pressure mercury lamp, metal halide lamp, etc. as an irradiation source) from above, development, washing with water, and post-baking.

Next, a negative-positive type water-soluble photoresist (for example,
Fuji Pharmaceutical Co., Ltd. FCR-7° FR-14, FR-15, Tokyo Ohka Kogyo Nonkron G-90, etc.) is coated and baked in a boiler, and then the desired circuit is formed as a photomask having a pattern for deep etching. Circuit pattern negative film A4 (first
5) is placed so as to overlap the pattern of the lower layer etching resist 23, and after irradiating ultraviolet rays from above,
Develop, wash, and post-bake.

As a result, etching resists 23 and 24 consisting of two layers, a lower layer and an upper layer, are formed on the metal original plate 22.

(3) Etching process The lower layer etching resist 23 (
Negative-positive type organic solvent type photoresist TPR
. When this is deeply etched with a ferric chloride solution of 35°Be' to 42°Be' as the first etching, the result is as shown in FIG. 19.

The portion etched at this time will also be etched during the second etching, so the etching should be made shallower.

After the first etching is completed, remove the remover (5-20%
As shown in FIG. 20, the upper layer of etching resist 24 is peeled off using an aqueous solution of sodium hydroxide, etc.).

Next, the metal plate 25 thus obtained is etched a second time using a ferric chloride solution of 35 to 42 DEG Be, resulting in the result as shown in FIG.

Thereafter, the underlying etching resist 23 is removed using a removal solution (a removal solution dedicated to each photoresist).

In this way, a mold 26 having a blade 27 is manufactured as shown in FIG. 22.

Note that the width a of the photomask (circuit pattern negative film A3 consisting of the edging of the desired circuit pattern as shown in FIG. 14) having a pattern for shallow etching is
By changing the blade shape, you can choose between a blunt blade type and a sharp blade type.
Furthermore, a circuit pattern punching die for printed wiring with a sharp blade is manufactured.

As is clear from the above explanation, compared to the conventional manufacturing method, the manufacturing method of the present invention allows the manufacturing method of the present invention to be used from a single original drawing, by simply using an ordinary photolithography camera and light source, and without the complicated conventional methods. A circuit pattern negative consisting of a border for forming an etching resist without the use of special techniques and procedures, and without the use of special equipment, very precise drafting techniques, or very careful attention to detail in the drafting process. It is possible to easily create a film and a negative film having a circuit pattern wider than the circuit width of the desired circuit pattern.

In addition, circuit pattern negative films consisting of edges have large tolerances in pattern positioning because the edges are used to form the cutting edge of a mold, and in the etching resist forming process, lower layers with different properties, Since the upper layer of etching resist is formed, unlike the conventional manufacturing method,
In order to create an etching step, an acid-resistant resin is attached between the first and second etching, an etching resist is formed again, a second etching is performed, and the acid-resistant resin is removed by heating and softening. The effects are outstanding, such as eliminating complicated processes and greatly simplifying the etching process.

[Brief explanation of drawings]

Figures 1 to 9 are diagrams for explaining the conventional manufacturing method, of which Figures 1 and 2 are plan views of negative films each having a circuit pattern slightly wider than the desired wiring circuit pattern. 3 and 4 are sectional views showing the procedure for obtaining the circuit pattern of the negative film shown in FIG. 1 on a metal original plate by etching, and FIG.
FIG. 6 is a plan view and a cross-sectional view of a positive film having a circuit pattern slightly narrower than the desired wiring circuit pattern, and FIGS. 7, 8, and 9 are etching of the metal plate shown in FIG. FIG. 3 is a cross-sectional view showing a procedure for processing and manufacturing a mold having a blade-shaped circuit pattern. 10 to 22 are diagrams for explaining the manufacturing method according to the present invention. Among these, FIGS. 10 to 15 show a patterned photomask (negative film) consisting of a border of a desired circuit pattern and a FIG. 16 is a plan view showing the procedure for creating a patterned photomask (negative film) having a circuit width wider than the circuit width of the circuit pattern of FIG. 17 is a curve diagram showing the relationship between the exposure time and the amount of line width thickening in the above-mentioned apparatus, and FIGS. 18 to 22 show an etching process for a metal original plate to produce a mold having a blade-shaped circuit pattern. FIG. 13... Desired circuit pattern including engineering cost, 1
5... A circuit pattern slightly thicker than the desired circuit pattern 13, 16... A circuit pattern consisting of the border of the desired circuit pattern, 17... A circuit pattern having a circuit width wider than the circuit width of the desired circuit pattern, 22... ...Metal original plate, 23, 24...Etching resist, 26...Mold,
A3...Circuit pattern photomask (negative film) consisting of a border of a desired circuit pattern, A4...A pattern photomask (negative film) having a circuit width wider than the circuit width of the desired circuit pattern.

Claims (1)

[Claims] 1. A method for manufacturing a circuit pattern punching die having a blade suitable for punching metal foil into a circuit pattern, the inside of the blade being shallowly recessed, and the outside thereof being deeply recessed. A first photomask having a circuit pattern shape corresponding to the pattern and consisting of an edging that allows etching of the desired circuit pattern; and a desired circuit pattern formed to cover the edging pattern of the first photomask. A first step of creating a second photomask having a circuit width wider than the circuit width, and applying a negative-positive type organic solvent-based mold onto the metal plate in the first photomask so as to correspond to the pattern of the blade. a second step of forming a lower layer etching resist using a photoresist; and using a second photomask, forming a lower layer etching resist using a negative-positive type water-soluble photoresist in a manner corresponding to the pattern of the lower layer etching resist. a third step of forming an upper layer of etching resist to form a deeply recessed part of the mold; a fourth step of deeply etching the metal plate on which the etching resist was provided in the second step; A fifth step of peeling off the upper layer of etching resist formed in the second step on the surface of the metal plate, and a shallow etching of the metal plate on which the etching resist was provided in the first step, A circuit pattern punching mold comprising a sixth step of forming a depressed portion and a seventh step of peeling off the underlying etching resist formed in the first step on the metal surface thus obtained. manufacturing method.