JPS5848039B2 - Electrolytic etching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for electrolytically etching a metal workpiece having a curved surface on which uniform electrolytic etching is difficult or impossible over the entire surface, and more specifically, a method for electrolytically etching a metal workpiece having a curved surface on which uniform electrolytic etching cannot be performed. 77 [] 1 construction material
The present invention relates to an electrolytic etching method in which electrolysis is carried out by repeatedly using a mold pattern made of an electrically insulating material and spraying an electrolytic solution onto the surface of the metal workpiece.

Conventionally, electrochemical means and chemical means are known as means for etching metal.

The former method of electrochemically etching metal includes the following three methods.
There are various methods.

(1) A method in which a corrosion-resistant resist pattern is provided on a metal surface and left in an electrolytic solution, the metal is used as an anode and an insoluble metal is used as a cathode, and only the bare metal portion is electrolytically eluted.

(2) A method commonly known as electrolytic processing method, using a molded cathode,
The mold cathode is brought close to the metal surface which is the anode, and the electrolytic solution is ejected from the nuclear mold cathode and etched, and as the etching progresses, the void is kept the same and the mold is gradually inserted into the deep part of the etched part. Method.

(3) Using a method known as the electrolytic marking method, a water-retaining stencil with an opening and a water-retaining substance present on the opening is wetted with an electrolyte and then brought into contact with metal, and a cathode is attached to the stencil. A method of electrolytic etching to a minute depth by bringing the metal into contact and applying electricity to it as an anode.

The first method of etching metal using a resist is to print the resist on the metal and dry it to form a pattern, or to apply a photoresist on the metal and dry it, then create a pattern opposite to the desired pattern. A method is used in which a pattern is exposed, then developed and dried to form a desired pattern.

When performing decoupling with a resist pattern in mind, (1) metal pretreatment, (2) drying, (3) resist printing, (4) drying, (5) electrolytic etching, (6) ) washing with water, (7
) Removal of resist, (8) washing, and (9) drying, which require 9 steps and 1 ton of operations.

Furthermore, when performing electrolytic etching after forming a pattern using photoresist, (1) metal pretreatment, (2) drying, (
3) Photoresist coating, (4) drying, (5) pattern exposure, (6) development, (7) drying, (8) baking, (
It requires an operation consisting of 13 steps: 9) car disassembly and etching, (1.0) water washing, 01) photoresist removal, 02) washing, and 03) drying.

As described above, in the method of etching metal using these resists, the resist or photoresist must be shaped each time the metal is etched, and the operation steps are many and complicated. However, it has the disadvantage of being expensive.

Furthermore, the second electrolytic processing method has the disadvantage that the electrode mold is expensive and that it is difficult to process complicated shapes.

Furthermore, in the third electrolytic marking method, the liquid is consumed instantaneously and the sludge does not accumulate, so there is a drawback that only extremely shallow etching of 2 to 3 microns can be performed.

Furthermore, as the latter chemical etching method, a flexible and corrosion-resistant template such as a rubber plate called a masking plate is used, and metal is clamped between the masking plate and the corrosion-resistant substrate to remove the non-etched parts. A method of performing chemical milling while protecting the

In this method, a large number of metals can be etched by repeatedly using one masking plate, so it has the advantage of efficiently etching metals at a low cost, but on the other hand, it requires repeated etching of simple shapes. In particular, this method cannot be applied to patterns with isolated parts like islands, and is unsuitable for etching over a dog area.
Furthermore, there is a drawback that processing accuracy is extremely low.

One of the inventors of the present invention first closely attached a mold pattern made of an electrically insulating material with openings corresponding to the areas to be etched onto a metal workpiece, and then placed an electrode facing the metal workpiece. The metal workpiece is electrolytically etched by passing an electric current using the metal workpiece as an anode and the electrode as a cathode while jetting an electrolytic solution between the metal workpiece and the electrode, and then The mold pattern is separated from the electrolytically etched metal workpiece, the separated mold pattern is brought into close contact with a second metal workpiece to be electrolytically etched, and the latter is electrolytically etched in the same manner as described above. The present invention has invented an electrolytic etching method characterized in that electrolytic etching is repeatedly performed on a metal workpiece to be electrolytically etched in sequence using a single die pattern, and the electrolytic etching method is different from the conventional method described above. Improve various shortcomings? It was very successful.

(See Patent Application No. 138617 of 1972).

However, in the electrolytic etching method using the above-mentioned mold pattern, for small metal workpieces, it is possible to avoid moving the electrode by using a flat electrode with an area corresponding to the area to be electrolytically etched. In both cases, the entire surface can be uniformly polished and etched at the same time.

However, it is difficult to apply uniform electrolytic etching over the entire surface of the metal workpiece, which has a surface that cannot be uniformly etched. When the patterns are closely spaced and a flat plate electrode is used, the distance between the flat electrode surface and the surface of the metal workpiece becomes uneven over the entire surface, resulting in uneven current distribution and uniform electrolytic etching is impossible.

The inventors of the present invention solved the above drawback by using an electrode having a shape corresponding to the shape of the curved surface of the metal workpiece with or without holes, and by placing the mold pattern facing the metal workpiece in close contact with the metal workpiece, and Alternatively, they succeeded in solving the problem by injecting an electrolytic solution between the metal workpiece and the electrode.

Therefore, the present invention provides an electrically insulating material having an opening on the outside corresponding to the area to be electrolytically etched on a metal workpiece having a curved surface that is difficult or impossible to uniformly electrolytically etch over the entire surface. The metal workpiece is placed in close contact with an electrode having a shape corresponding to the shape of the curved surface of the metal workpiece with or without a hole, and the metal workpiece and the electrode are placed opposite each other. During this process, an electrolytic solution is jetted from the hole of the electrode or from the outside of the electrode, and the metal workpiece is used as an anode, and the metal workpiece is used as a cathode, and the metal workpiece is etched through electric current,
Then, the nuclear pattern is separated from the electrolytically etched metal workpiece, and the separated mold pattern is electrolytically etched in the same manner as above in close contact with a second metal workpiece to be electrolytically etched; This electrolytic etching method is characterized in that the latter electrolytic etching is sequentially performed on metal workpieces to be electrolytically etched using one of the die patterns.

In the method of the invention, the electrodes may be stationary or may be moved with small amplitudes.

If the area of the metal workpiece is small, uniform electrolytic etching can be achieved by jetting the electrolyte from outside the electrode or between the metal workpiece and the electrode, but When the area is large, uniform electrolytic etching can be conveniently performed by jetting the electrolyte through holes provided in the electrode.

Type patterns that can be used in the method of the present invention include: (1) After applying an emulsion (for example, photosensitive photoresist) to an electrically insulating screen, an original plate is applied and exposed and developed to form an electrically insulating emulsion pattern. pattern pattern.

(2) A mold pattern made by applying an emulsion to a base film in advance, applying an original plate, exposing and developing it to form a direct insulating emulsion pattern, and then transferring the emulsion pattern to an electrically insulating screen.

(3) A mold pattern formed by forming an electrically insulating paste pattern on an electrically insulating screen using electrically insulating paste by hand drawing or screen printing.

(4) A mold pattern formed by opening an electrically insulating film and adhering the film to an electrically insulating screen.

(5) A mold pattern obtained by coating a pace film with a thick electrically insulating emulsion in advance, applying an original plate, exposing and developing it, and then peeling it off from the pace film.

(6) A mold pattern formed by opening an electrically insulating film.

etc. can be used.

As the screen material used for the mold pattern used in the method of the present invention, commercially available products usually made of silk, nylon, Tetoron thread, etc. can be used.

Resists for electrolytic shielding include polyvinyl cinnamate resists such as KPR (Kodak Photoresist), cyclized rubber resists KMFR (Kodak Metal Etch Resist whose main component is cis-polyisobrene), orthoquinone diazide resists such as AZ (manufactured by Situpre Co., Ltd. in the United States). ) is preferably used.

For other mold patterns, the selection of materials, construction, and other implementation guidelines described in the above-mentioned specification of Patent Application No. 138617 of 1987 can be followed.

According to the present invention, all metals or alloys such as iron, copper, brass, aluminium, nickel, chromium, lead, tin, zinc, stainless steel, permalloy, etc., in general terms, which are anodized at the anode and are not passivated. Can engrave metals and alloys.

As the electrolytic etching liquid used in the present invention, those conventionally used for various metals and alloys can be used.

Next, the electrolytic etching method of the present invention will be specifically explained based on the drawings in comparison with other methods.

FIG. 1 {1 is a cross-sectional view showing an embodiment in which the electrolytic etching method using the mold pattern proposed for the sac by one of the present inventors is applied to electrolytic etching of a metal workpiece having a curved surface, 1
2 is a metal DO workpiece having a curved surface connected to the anode side of the power source 6, 2 is an opening of the mold pattern 2, 4 is an electrode connected to the cathode side of the power source 6, and 5 is an electrolyte jet hole.

In such a case, electrolytic etching is performed using the thin electrode 4 while sliding it along the surface of the metal workpiece, which makes it difficult to perform electrolytic etching uniformly and reduces the overall electrolytic etching. The disadvantage is that it consumes a considerable amount of time.

Figure 2 is a cross-sectional view of a metal workpiece with a curved surface, the mold pattern being the same as in Figure 1, but using a large flat cathode as the cathode; 1 is the anode of electrode 6; 2 is a mold pattern, 3 is an opening in the mold pattern, and 4 is a large flat electrode with a large number of electrolyte jet holes 5 connected to the cathode side of a power source 6. .

In such cases, the distance between the metal workpiece, which is the anode, and the large flat electrode, which is the cathode, is not constant, so even if the electrolyte jet is uniform, the electrolytic etching is not uniform. be.

FIG. 3 is a cross-sectional view showing the most preferable example of the method of the present invention, in which a metal workpiece 1 having a curved surface is connected to the anode side of the power source 6.
A mold pattern 2 having an opening 3 is placed in close contact with the metal workpiece 1 and has a large number of electrolyte jet holes 5 connected to the cathode side of a power source 6 facing the exposed metal workpiece 1, and the lower end of the mold pattern 2 is connected to the metal workpiece 1. An electrode 4 having a curved surface corresponding to the curved surface of the material is disposed, and an electrolytic solution is jetted from the electrolyte jet hole 5 between the metal workpiece 1 and the electrode 4, and a current is applied between the metal workpiece 1 and the electrode 4. The metal workpiece 1 is electrolytically etched through a superimposed current, and after the etching is completed, the mold pattern 2 is removed from the metal workpiece 1, and the mold pattern 2 is pressed onto the metal workpiece 1 to be processed next. After that, the electrolytic etching process described above is repeated, and one die pattern 2 is repeatedly used to electrolytically etch a large number of metal workpieces.

According to the method of the present invention, the electrolytic solution is jetted evenly, and the distance between the metal workpiece (anode) and the cathode is equal in addition to the uniform composition and conductivity of the electrolytic solution, resulting in uniform electrolysis. Compared to the method shown in FIGS. 1 and 2, electrolytic etching has the advantage of being uniform and faster.

Next, examples of the present invention will be shown.

After coating KMER (Kodak Metal Etch Resist) on a 250 line/inch Tetron screen, the pattern is baked and developed to produce a mold pattern.

The thickness of the resist for the mold pattern is 50 μm.

This mold pattern has a diameter of 80 m with a convex surface of 300 mH.
300m with an outer diameter of 80ii by pressing it closely against a steel material of m.
A concave electrode with a curved surface of mR is 0.0 mR from the mold pattern. 5
mvt apart, electrolytic etching solution (15φN
aNos aqueous solution) was jetted at a pressure of 2 kg/cvt from the electrolyte jet hole provided on the concave electrode, and the steel material was connected to the anode side of the power source and the concave electrode to the cathode side of the power source to generate approximately 30 A/cI?
Electrolytic etching is performed by applying a current of L for 20 seconds.

As a result, the depth of the electrolytic etching was approximately 0.15 mm, which was approximately 4 times the electrolytic etching rate when electrolytic etching was performed by moving the thin electrode as shown in Figure 1. was gotten.

Further, when electrolytic etching was performed by repeatedly using the above mold pattern, approximately 1,000 pieces of steel material could be electrolytically etched.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the car disassembly etching method using the mold pattern proposed by one of the present inventors for the electrolytic etching of a metal workpiece having a curved surface; FIG. 2 is a cross-sectional view of a case where a metal workpiece having a curved surface is used as a cathode and a large flat electrode, and FIG. 3 is a cross-sectional view showing a most preferred example of the method of the present invention. 1... Metal workpiece material, 2... Mold pattern, 3... Opening of mold pattern 2, 4...
...Cathode, 5...Electrolytic etching liquid jet hole, 6...
···power supply.

Claims (1)

[Claims] 1. A mold pattern made of an electrically insulating material with an opening corresponding to the area to be electrolytically etched is closely attached to a metal workpiece having a curved surface on which it is difficult or impossible to perform uniform electrolytic etching over the entire surface. The metal workpiece is provided with an electrode having a shape corresponding to the shape of the curved surface of the metal workpiece with or without a hole, and the hole of the electrode is placed between the metal workpiece and the electrode. The metal workpiece is electrolytically etched by passing an electric current through the metal workpiece using the metal workpiece as an anode and the electrode as a cathode while an electrolytic solution is jetted from the outside or from the outside of the electrode, and then the mold pattern is electrolytically etched. The separated mold pattern is electrolytically etched in the same manner as above in close contact with a second metal workpiece to be electrolytically etched, and then the latter is sequentially electrolytically etched. An electrolytic etching method characterized in that a metal workpiece to be electrolytically etched is repeatedly etched using one of the die patterns.