JPS5843478B2 - Electrolytic etching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolytic etching method, and more specifically, to a method of electrolytically etching only a target area to be etched, with almost no side etching occurring.

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 standing in an electrolytic solution, the metal is used as an anode and an insoluble metal is used as a cathode, and only the exposed 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 jetted out from the mold cathode and etched, and as the etching progresses, the electrolyte is gradually introduced into the deep part of the etched part while keeping the gap the same. 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 form a pattern by screen printing the resist onto the metal and drying it, or by drying the photoresist onto the metal and forming the desired pattern. A method is used in which a pattern opposite to the above is used for exposure, then development and drying to form a desired pattern.

When forming a pattern by screen printing and performing electrolytic etching, (1) metal pretreatment, (2) drying, (3)
Resist printing, (4) drying, (5) electrolytic etching, (6) washing with water.

It requires an operation consisting of nine steps: (7) resist removal, (8) washing, and (9) drying.

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) electrolytic etching, 0Φ human washing, C11) photoresist removal, (6) washing, and α imaging.

As described above, in the method of etching metal using these resists, the resist or photoresist must be formed 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, the third electrolytic marking method has the disadvantage that the liquid is consumed instantaneously and 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. There is a known method for performing chemical milling while protecting the skin.

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 having isolated parts like islands, and is unsuitable for etching over a large 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 - pieces of the pattern, and the electrolytic etching method described above is improved. succeeded in improving the various shortcomings of

(See Patent Application No. 138617 of 1972).

However, in this electrolytic etching method, the phenomenon of side etching occurs as in the case of chemical etching, and therefore 1
When performing deep etching using a die pattern,
There is a drawback that side etching inevitably occurs, and the side etching becomes large, resulting in significant deformation of the transferred image of the mold pattern.

In view of the above-mentioned drawbacks, the present inventors have conducted various studies on performing electrolytic etching with less side etching to prevent deformation of the transferred image of the desired mold pattern, and as a result, the present inventors have developed the present invention. The gist of the invention is to create a first plate made of an electrically insulating material having an opening of a desired size smaller than the area of the area to be etched in the metal workpiece. The mold patterns are brought into close contact, an electrode is opposed to the metal workpiece, and an electrolytic etching liquid is jetted between the metal workpiece and the electrode, and the ferrous metal workpiece is used as an anode, and the electrode is The metal workpiece is first electrolytically etched (to a desired depth of about 50 to 70 mm) by passing an electric current through it using the metal as a cathode,
Next, a first step is performed in which the first mold pattern is separated from the electrolytically etched metal workpiece, and then the first mold pattern is etched to a desired size, although it is larger than the area of the opening of the first mold pattern. A second die pattern having an opening smaller than the area of the area is closely attached to the metal workpiece with the center of the opening matching the center of the electrolytically etched part of the metal workpiece in the first step. , carry out a second step of electrolytic etching (up to about 90% of the desired depth) following the electrolytic etching of the first step, and then finally etching an area of the same size as the area to be etched to the desired size. A third mold pattern made of an electrically insulating material having an opening is closely attached to the metal workpiece with the center of the opening aligned with the center of the electrolytically etched part of the metal workpiece in the second step. This electrolytic etching method is characterized by electrolytically etching to a desired depth and etching a region of a desired size with a small amount of side etching, following the electrolytic etching process described above.

The mold pattern that can be used in the method of the present invention is as follows: (1) An electrically insulating emulsion pattern is formed by applying an emulsion (for example, photosensitive photoresist) to an electrically insulating screen, applying an original plate, and performing exposure and development. type pattern.

(2) A mold pattern formed by applying an emulsion to a base film in advance, applying an original plate, exposing and developing it to form an electrically 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 by hand drawing or screen printing using electrically insulating paste.

(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 base film with a thick electrically insulating emulsion in advance, applying an original plate, exposing and developing it, and then peeling it off from the base film.

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

tL etc. can be used.

As the screen material used for the mold pattern used in the method of the present invention, commercially available products made of current-carrying phase, nylon, Tetron thread, etc. can be used.

Examples of electrolytic shielding resists include polyvinyl cinnamate resists, KPR (Kodak Photoresists), cyclized rubber resists KMER (Kodak Metal Etch Resists whose main component is cis-polyisoprene), and ornquinone diazide resists such as AZ (USA). It is preferable to use a solvent soluble photoresist such as Silapray Co., Ltd.).

For other mold patterns, the selection of materials described in the above-mentioned Patent Application No. 138617 of 1972,
structure and other implementation guidelines.

According to the present invention, all metals or alloys such as iron, copper, manazuru, aluminium, nickel, chromium, lead, tin, zinc, stainless steel, permalloy, etc., in general terms, 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.

FIGS. 1, 2, and 3 are front views, partially in section, of an embodiment of the electrolytic etching method of the present invention comprising three steps.

1, 2, and 3, 1 is a cathode connected to the cathode side of a power source 8, 2 is an electrolytic etching liquid jet device, and 3 (
Figure 1).

3' (Fig. 2) and 3〃 (Fig. 3) are mold patterns, 4
(Fig. 1), 4' (Fig. 2) and 4 (Fig. 3) are the openings of the mold patterns 3, 3' and y, respectively, and 6 (the first
), 6' (Figure 2) and 6 (Figure 3) are metal workpieces connected to the anode side of the power source 8; 5 (Figure 1), 5' (
2) and 5// (FIG. 3) are metal workpieces 6, 6' and 5/, t7) electrolytically etched parts, 7 is a support for the metal workpiece, and 8 is a power source.

In the method of the present invention, as shown in FIG. 1, a metal workpiece material 6 serving as an anode is placed on a support base, a mold pattern 3 having an opening 4 is placed in close contact with the metal 6, and electrolysis is performed. Electrolytic etching is performed by supplying current from a power source 8 between the metal workpiece material 6 and the cathode 1 while jetting the electrolytic etching liquid from the etching liquid jet device 2 .

However, the opening 40 of the mold pattern 3 used in this case
The area of the mold pattern 3/47) is equal to the area of the desired electrolytically etched portion 5 shown in FIG. The electrolytically etched portion 5 is formed by electrolytic etching to a depth close to that of , and then the mold pattern 3 is removed.

Next, as shown in FIG. 2, the area of the opening 4' of the mold pattern 3' used is the same as that of FIG. The area of the desired electrolytically etched portion 5 shown in FIG. 3 is larger than that of 4.
A mold pattern 3 having an area smaller than the incision 4 is used to create a desired electrolytically etched area larger than the area and deeper than the electrolytically etched area 5 in the case of FIG. Electrolytically etched portion 5 smaller than the area and shallower than the depth of 5
Electrolytic etching is performed as before, and then the mold pattern 3' is removed.

Continuing on, as shown in Figure 3, Figures 1 and 2
As in the case shown in the figure, however, in this case, the mold pattern 3 used has an opening I with an area equal to the area of the desired electrolytically etched portion 5, so that side etching does not occur. Electrolytic etching is performed to obtain an electrolytically etched portion 5 having a desired area and depth, and then a mold pattern 3 is formed.
leave.

In this case, three mold patterns are used and an electrolytically etched portion having the desired area and depth with less side etching can be obtained in three steps, making it possible to perform electrolytic etching with high precision. It is.

The number of mold patterns used and the number of steps are not limited to the three mold patterns and three steps mentioned above, but can be any number of mold patterns depending on the area size and depth of the intended electrolytically etched portion. Alternatively, high precision electrolytic etching can be performed by selecting an arbitrary number of steps.

According to the present invention, it is only necessary to prepare one mold pattern for each electrolytic etching process, and each electrolytic etching process can be performed by repeatedly using that one mold pattern. This method has advantages over conventional electrolytic etching methods in terms of operational simplicity and economy, since it is sufficient to prepare a number of mold patterns according to the number of mold patterns.

In the method of the present invention, instead of using the third mold pattern described above, a photoresist image or a screen-printed image corresponding to the third mold pattern is applied to the workpiece in advance, and then the method of the present invention The accuracy of drawing lines is improved by a method in which the above-mentioned first and second steps using a mold pattern are carried out in combination with the conventional method of performing electrolytic etching using the photoresist or screen printing image as a resist in the final step. I can do it.

In the method of the present invention, deep electrolytic etching has been described above using several mold patterns that have the same shape but differ only in size. Since the same metal workpiece can be electrolytically etched to different depths, interesting decorative plates and the like can be produced.

In the method of the present invention, if necessary, when performing electrolytic etching using different die patterns using a laminated metal plate in which different metals are laminated as a metal workpiece, the metal of each metal layer is placed on one metal plate. A product having a scattered pattern image formed thereon can be obtained.

Next, examples of the present invention will be shown.

Example 1 After applying KMER (Kodak Metal Etch Resist) on a 200-line/inch Tetron screen, the pattern was printed and developed to create three mold patterns 3.
, 3' and 3〃 are prepared.

Regarding the dimensions of the mold pattern, please refer to the drawing line of mold pattern 3' (
The non-etched part) is 0.3 larger than mold pattern 3,
The drawing line (non-etched portion) of mold pattern 3 was adjusted to be 1.0 larger than that of mold pattern 3'.

First, use mold pattern 3 and add area 2 to the mold pattern.
00JX A copper plate with a thickness of 7 wIL was pressed closely together, a cathode was placed opposite the copper plate, the copper plate was used as an anode, and an electrolytic etching solution (15% by weight NaNO3 aqueous solution) was jetted between the two electrodes. Electrolytic etching was performed to a depth of 1.0 mX.

The current density was about 40 A/crA, and the electrolytic etching time was 10 minutes.

After the electrolytic etching is completed, the mold pattern 3 is removed from the copper plate, and then the mold pattern 3' is aligned with the electrolytically etched portion of the copper plate and pressed down, and the same process as the above is performed to obtain a total depth. Electrolytic etching was performed until the particle size was 1.2 mm.

After the electrolytic etching using the mold pattern 3' was completed, electrolytic etching was performed using the mold pattern ν having the desired image lines to a total depth of 1.3 mm in the same manner as in the previous step.

The electrolytically etched portion had almost no side etching, had the desired depth, and was extremely accurate.

Example 2 Using the same method as in Example 1, but instead of using mold pattern y, a pattern with the same drawing line as mold pattern ν was made on a copper plate in advance, and then mold patterns 3 and 3 were prepared.
', and finally, etching was performed using the resist plate-making image.

Compared to Example 1, a sharper etched plate could be obtained.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are front views, partially in section, of an embodiment of the electrolytic etching method of the present invention comprising three steps. 1... cathode, 2... electrolytic etching liquid jet device, 3°3' and ν... type pattern, 4.
4' and 4...Kata pattern 3, 3 and 3
openings, 5, 5 and 5...electrolytically etched parts, 6, 6' and 6...metal workpieces,
7... Support stand, 8... Power supply.

Claims (1)

[Claims] 1. A first mold pattern made of an electrically insulating material having an opening of a desired size smaller than the area of the area to be etched is brought into close contact with the metal workpiece, and an electrode is placed opposite the metal workpiece, Electrolytically etching the metal workpiece by flowing an electrolytic etching solution between the metal workpiece and the electrode, using the metal workpiece as an anode and the electrode as a cathode, and then electrolytically etching the metal workpiece through a current. A first step of separating the first die pattern from the electrolytically etched metal workpiece is performed, and then the area of the area to be etched is set to a desired size, but larger than the area of the opening of the first die pattern. A second mold pattern having a smaller opening than the first mold is placed in close contact with the metal workpiece with the center of the opening coincident with the center of the electrolytically etched portion of the metal workpiece in the first step. A second step of electrolytic etching is performed in the same manner as the electrolytic etching step, and finally a third step made of an electrically insulating material having an opening of the desired size and the same area as the area to be etched is carried out. The mold pattern is brought into close contact with the metal workpiece with the center of its opening aligned with the center of the electrolytically etched portion of the metal workpiece in the second step, and electrolytic etching is performed in the above step;
An electrolytic etching method characterized by obtaining etching of a desired size with almost no side etching.