JPS587706B2 - Etching method with steps - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming steps on a single metal plate by changing the etching depth depending on the purpose using an etching method. The present invention relates to the production of circuit pattern punching dies used in the manufacturing of circuit pattern punching dies, and particularly relates to the production of circuit pattern punching dies having blades suitable for punching metal foil into circuit pattern shapes.

For example, an etching method has been well known as one of the methods for manufacturing a mold for punching circuit patterns.

In this method, a method for manufacturing a circuit pattern punching die having a blade suitable for punching a circuit pattern from metal foil onto an organic insulating substrate (for example, Japanese Patent Publication No. 50-32
No. 651, JP-A-48-1864, JP-A-51-32
No. 959), as a circuit pattern photomask used for forming an etching resist, a circuit pattern negative film slightly wider than the desired wiring circuit pattern and a circuit pattern positive film slightly narrower were prepared. A mold with a blade shape is manufactured by etching it twice and adding a step.

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

Circuit pattern 1 slightly wider than the desired wiring circuit pattern
An etching resist l-2 (Fig. 3) is formed on the metal original plate 3 using a negative film A (Figs. 1 and 2) having (FIG. 4), and then a seventh layer of acid-resistant resin 9 made of, for example, epoxy resin is applied to the recessed portion 6 of the metal plate 5.
Fill as shown.

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.

There are two important points in the manufacturing process of the mold with the blade type seen in this conventional example. One is that etching is performed twice using two photomasks to form an etching resist. After forming an etching resist with the first mask, perform deep etching, apply acid-resistant resin to the etched area to prevent further etching, and then form an etching resist with the second mask and then perform shallow etching. It is etching.

The other problem lies in the method of creating a photo mask for forming the etching resist during this manufacturing process, with negative film A having a slightly wider circuit pattern and positive film B having a slightly narrower circuit pattern. .

Therefore, 2, which is used to form conventional etching resists,
A first example of a method for creating circuit pattern films A and B for boards will be described.

Negative film A is prepared by estimating the etching allowance for the desired circuit pattern, drawing an enlarged original drawing (trace drawing) to reduce operational errors, and using the photographic scale method to create the original size (slightly smaller than the desired circuit pattern as it includes the etching allowance). created by widening).

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

First, the etching resist 2 shown in FIG. 3 is formed using negative film A, and deeply etched by an etching method.
Make a mold as shown in Figure 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 concave portion 6.

Thereafter, 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 made from this negative film using ordinary photographic methods.

By attaching this positive film to a special printing device that makes a circular vibration motion and printing it onto photographic film while shaking the positive film slightly, a negative film with a circuit width narrower than the desired circuit pattern width is created. Ru.

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

A second example of the method for creating the circuit pattern films A and B will be explained as follows.

For negative film A, estimate the etching allowance for the desired circuit pattern, draw an original drawing (trace drawing) enlarged 1.5 to 2 times to reduce drawing errors, and then print it to the original size (including the etching allowance) using the photographic scale method. It is created by making the circuit pattern slightly wider than the desired circuit pattern.

Next, on the positive film B, draw an original drawing (trace drawing) with a circuit pattern width slightly narrower than the desired circuit pattern width, and enlarge it by 1.5 to 2 times in order to reduce drawing errors.
Created by scaling to actual size using photographic scaling.

Conventionally, acid-resistant resin was installed and filled to form a flat surface at the same height as the unetched areas, and after etching, this had to be removed by heating and softening. There are drawbacks.

Furthermore, the etching resist forming process has the following drawbacks.

That is, when creating the negative film A and positive film B necessary for forming the etching resists 2 and 8, the first conventional example described above requires complicated techniques and processes (method for accurately copying the flat circuit pattern 4). In addition, in the second conventional example described above, an original pattern (trace pattern) wider than the desired pattern width and an original pattern (trace pattern) narrower than the desired pattern width are drawn. Negative and positive films are created using the photographic method, but when creating a complex circuit pattern, two original drawings (trace drawings) that are completely similar to the desired pattern, one slightly wider and one slightly narrower, are used. Writing is very difficult in current artwork work, requiring advanced drawing techniques such as very precise drawing machines and careful workmanship, and a lot of work time.

Furthermore, in the etching process, in both the first and second conventional examples, when manufacturing a mold for printed wiring with a large area, the etching process is slightly smaller than the desired wiring circuit pattern used when forming the etching resist 8 shown in FIG. It is extremely difficult to align positive film B (Figure 5), which has a narrow circuit pattern, and the required mold cutting edge (11 in Figure 9) is unbalanced on the left and right due to a deviation of several tens of microns. Therefore, one side of the blade is relatively thick, but the other side tends to have a very thin cutting edge.

The present invention is an improvement in the manufacturing method of a die for punching circuit patterns in consideration of the above-mentioned drawbacks.
Regarding the disadvantage of using acid-resistant resin, which requires a complicated process, we have simplified the process by using two types of photoresists with different properties: an organic solvent type and a water-soluble type as etching resists. Regarding the second and third drawbacks, the mask pattern creation process is complicated and requires special equipment or advanced drawing techniques, and the tolerance for pattern positioning during etching is small. A circuit pattern photomask (negative film) consisting of an original drawing (trace drawing), a border of a desired circuit pattern created using ordinary photographic techniques, and a pattern photomask (negative film) having a circuit width wider than that of the desired circuit pattern. The present invention provides an etching method that can easily form a step by etching twice using a film.

An embodiment of the present invention will be described below based on the drawings.

The explanation 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, as shown in Fig. 12) Create.

Negative film A is obtained by reducing this enlarged original drawing 12 to the original size (the size of the desired printed wiring circuit pattern including etching costs, 13 in FIG. 11) using an ordinary photolithography camera.
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 18 as shown in Fig. 16, and place the original 19 (the original size A negative film A1) as shown in FIG. 11, which has been reduced in size, is placed on top of the contact glass 20, and a point light source (contact printing lamp) 2 is applied from above.
Expose at 1.

The unexposed film 18 is a negative type photographic film, such as Kodak Super Speed Duplicating Film No. 2551, the amount of light diffusion is changed by changing the exposure amount (exposure time) as shown in FIG. 17, 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 is mounted as the original 19, and the unexposed film 18 of the negative type is exposed for an exposure time whose thickness corresponds to a in FIG. 14, and then developed, fixed, and washed with water. A slightly thicker circuit pattern (No. 13)
A negative film A2 having 15) in the figure is obtained.

On the other hand, a positive film B1 having a circuit pattern (14 in FIG. 12) of the same size as the circuit pattern 13 of the negative film A1 is prepared by applying proper exposure to the negative film A1 of FIG. In FIG. 16, a negative type photographic film (for example, Kodatsu Lith Film No. 2551) is used as the unexposed film 18, and the original 1
9, the positive film B1 shown in FIG. 12 and the negative film A2 shown in FIG. Pattern (16 in Figure 14)
) is produced.

Next, using a vacuum printing frame or the like, place a negative type photographic film as an unexposed film 18 as shown in FIG.
Place the negative film A1 shown in the figure, and set the exposure time so that the line width of the circuit pattern covers the cutting edge of the mold, for example, the exposure time is the same as or thicker than the pattern in Figure 11. Refer to Figure 17 and make your selection.

After exposure, development, fixing and washing are performed to produce a negative film A4 having a circuit pattern (17 in FIG. 15) having a wider circuit width than the desired circuit pattern.

(b) Etching resist forming process As shown in FIG. 18, a metal original plate 22 (low carbon steel such as carbon tool steel SK-3 or hardened steel) is coated with organic solvent-based photo as a first etching resist 23. Resist (e.g. TPR manufactured by Tokyo Ohka Kogyo, KPR manufactured by Kodak)
etc.) with a wheeler, then place a circuit pattern negative film A3 (Fig. 14) consisting of the edging of the desired circuit pattern as a photomask with a pattern for shallow etching on top of it, and then apply ultraviolet light (metal halide lamp) from above. etc.), then developed, washed with water,
Post bake.

Next, a water-soluble photoresist (for example, FCR-7 manufactured by Fuji Pharmaceutical Co., Ltd.
, Aquaresist #100 (manufactured by Yoshitani Shokai, etc.) is coated and baked with a wheeler, and a circuit pattern negative film A4 (No. 15) is used as a photomask having a pattern for deep etching. ) is placed so as to overlap the pattern of the first etching resist 23, irradiated with ultraviolet rays (such as an ultra-high-pressure mercury lamp or a metal halide lamp), and then 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.

(c) Etching process The first etching resist 23 (
When the metal original plate 22 on which the solvent-based photoresist TPR) and the second etching resist 24 (water-soluble photoresist FCR-7) are formed is deeply etched as the first etching, the result is as shown in FIG.

The part etched at this time will also be etched during the second etching, so the etching should be done shallowly. After the first etching is finished, remover solution (
20 using 5-10% sodium hydroxide aqueous solution)
The second etching resist 24 is peeled off as shown in the figure.

Next, a second shallow etching is performed on the metal plate 25 thus obtained, resulting in the result 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. 22.

In addition, by changing the width of a of the photomask (circuit pattern negative film A3 consisting of the edging of the desired pattern in Fig. 14) having a pattern for shallow etching, a blunt blade type, a sharp blade type, and even a sharp blade type can be formed. A circuit pattern punching die for printed wiring with a 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, light source, etc. A circuit pattern negative consisting of a border for forming an etching resist without the use of specialized techniques and procedures, and without the use of special equipment, very precise drafting techniques, or very detailed considerations in drafting work. A negative film having a circuit pattern wider than the circuit width of the film and the desired circuit pattern can be easily produced.

In addition, since the circuit pattern negative film consisting of the edging is used to form the cutting edge of the mold, there is a wide tolerance for pattern positioning, and in the etching resist forming process, the first and second Since an etching resist has been formed, as in the conventional manufacturing method, in order to create an etching step, an acid-resistant resin is attached between the first and second etching, and an etching resist is formed again. This has great effects, such as the fact that the etching process is greatly simplified, since there is no need for complicated processes such as performing the second etching and finally removing the acid-resistant resin by heating and softening.

[Brief Description of the Drawings] Figures 1 to 9 relate to the conventional manufacturing method, Figures 10 to 22 relate to the manufacturing method of the present invention, and Figure 1 shows a circuit slightly wider than the desired wiring circuit pattern. A plan view of a negative film having a pattern, FIG. 2 is a sectional view of FIG. 1, and FIGS. 3 and 4 are sectional views showing the procedure for etching the circuit pattern of the negative film shown in FIG. 1 on a metal original plate. , FIG. 5 is a plan view of a positive film having a circuit pattern slightly narrower than the desired wiring circuit pattern, FIG. 6 is a sectional view of FIG. 5, and FIGS. 7 to 9 are views of the metal plate of FIG. 10 to 15 are cross-sectional views showing the steps of etching and manufacturing a mold having a blade-shaped circuit pattern. FIGS. A plan view showing the procedure for creating a pattern photomask (negative film) having a circuit width wider than the circuit width, FIG. 16 is an explanatory diagram of the apparatus used to create the two types of photomasks, and FIG. 17 is an exposure diagram in the apparatus. A characteristic diagram showing the relationship between time and line width thickening,
Figures 18 to 22 show the etching treatment of the original metal plate.
FIG. 3 is a cross-sectional view showing a procedure for manufacturing a mold having a blade-shaped circuit pattern. 13...Desired circuit pattern with etching allowance taken into account, 15...Circuit pattern slightly thicker than desired circuit pattern 13, 16...Circuit consisting of the border of the desired circuit pattern Pattern, 17...
・Circuit pattern having a circuit width wider than the circuit width of the desired circuit pattern, 22... Metal original plate, 23, 2
4... Etching resist, 26...
Mold, 27...Blade mold, A3...Circuit pattern photomask (negative film) consisting of the border of the desired circuit pattern, A4...Circuit width of the desired circuit pattern A patterned photomask (negative film) with a wider circuit width.

Claims (1)

[Claims] 1 Using two types of photomasks with different pattern shapes and two types of etching resists with different properties, they are baked onto a metal plate so that the patterns overlap with each other, and after the first etching is completed, one of the etching resists is 1. An etching method with steps, characterized in that a metal plate with steps is manufactured by peeling off and then performing a second etching.