JPH05124172A - Metal perforated plate and production thereof - Google Patents

Abstract

PURPOSE:To form many through-holes having a sharp contour at a short pitch by forming a different kind of a metal layer to the surface of a base metal plate by an electroforming method and using said metal layer as a mask to perforate only the base metal plate by etching. CONSTITUTION:In the production of a metal mask for screen printing, a base metal plate 21 such as a phosphor bronze plate is washed and, after drying, a resist is applied to both surfaces of the metal plate 21 and subsequently exposed through a mask to be developed to form a resist pattern 22 so as to selectively coat the through-hole forming parts of both surfaces of the metal plate 21. Next, a different kind of a metal layer 23 composed of nickel or the like different from the base metal plate 21 with respect to etching resistance is formed to the exposed part having no resist pattern of the metal plate 21 in a plating bath by an electroforming method. Subsequently, the resist pattern 22 is removed by a release solution to perform etching using a different kind of the metal layer 23 as an etching resist and the substrate metal plate 21 is dissolved to form through-holes 24....

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved metal perforated plate in which minute through holes with high accuracy are formed and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in the production of metal masks used for screen printing, optical slit plates (encoder disks) and other metal perforated plates, methods of forming the through holes by methods other than machining are roughly classified. Two methods are known, an etching method and an electroforming method.

That is, according to the etching method, first, a metal plate having a predetermined thickness (for example, 100 to 200 μm) is washed and dried, and then a resist is applied on both sides, then exposed through a mask and developed, The exposed metal surface is etched with an etching solution to form a through hole. Then, the resist is removed to form a solid metal mask plate.

However, in the solid metal mask plate thus produced, as shown in FIG. 6, the through hole 2 formed in the metal plate 1 has the contour portion 2a in proportion to the thickness of the metal plate 1. However, there is a problem in that the sharpness of the holes causes a sharp decline, and the middle portion of the hole protrudes inward to lack verticality, and ink is accumulated in that portion. Further, it is difficult to adjust the etching depth, and it is difficult to obtain a hole having good hole accuracy.

On the other hand, in the electroforming method, a metal plate is washed and dried, then a resist is applied on both sides, then exposed through a mask and developed, and the exposed metal surface is electroformed to form a through hole. After the formation, the resist is removed and the electroformed layer is peeled off to complete the solid metal mask plate. This electroforming method is superior to the etching method in terms of accuracy and cross-sectional shape, but in terms of manufacturing speed, the electroforming speed is generally several tenths to several hundredths of the etching speed. There is a drawback that it takes a long time to process.

Then, as a modification of the etching method, for example, Japanese Patent Laid-Open No. 1-1309 shown in FIGS.
No. 7 discloses a method in which two kinds of metals having different etching resistances are laminated in three layers and each metal layer is corroded by each etching solution. Here, for example, a nickel layer 13 is attached to both surfaces of the base metal layer 12 made of copper or brass by a plating method to form a laminated body made of nickel-copper-nickel.

Then, a resist layer is formed on both upper and lower surfaces of the resist layer, masked, exposed and developed to form a resist pattern 14 (see FIG. 7). Next, using a chemical that does not corrode the base metal but only the plating metal (for example, an acidic etching solution composed of a mixed solution of hydrogen peroxide and nitric acid),
Only the exposed nickel layer 13 is etched (FIG. 8).
reference).

Next, the exposed base metal layer 12 is selectively etched with a chemical (alkaline etching solution) that does not corrode the plating metal but only the base metal, and the base metal layer 12 is etched.
A through hole is formed by passing through. Then, by removing the resist pattern 14, the solid metal mask plate 15 is formed (see FIG. 9).

However, even with this method, as shown in FIG. 8, the side etch 15 also progresses with the progress of the etching work, so that no matter how the resist pattern image line is modified, the through hole formation location is limited to a predetermined limit. As described above, there is a drawback that the line width L cannot be narrowed as the nickel layer becomes thicker and the etching depth becomes deeper. In addition, the peripheral part of the resist layer (the part surrounded by a circle in the figure) is a little irregular etching, which hinders high accuracy, so the problem of poor ink removal and inability to obtain smooth ink circulation remains. Remain.

[0010]

SUMMARY OF THE INVENTION The present invention was devised in view of the above-mentioned circumstances, and the high speed of the etching method was added while maintaining the high accuracy, which is an advantage of the electroforming method. An object of the present invention is to provide a metal perforated plate having a sharp contour and a method for manufacturing the same.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention has a method in which two kinds of metals having different etching resistances are laminated in three layers, and patterning for porosity is performed only in an intermediate metal layer. Was corroded with an etching solution, and the metal layer on the outside was patterned by electroforming.

That is, according to the first aspect of the invention, a resist pattern is formed by selectively covering the through-hole forming portions on both sides of the base metal plate, and the base metal plate is not coated with the resist pattern. A dissimilar metal layer different from the base metal plate in terms of etching resistance is formed on the exposed portions on both sides by electroforming, and the resist pattern is removed and the dissimilar metal layer remaining is used as a mask to form the dissimilar metal layer substantially. The technical means of etching the base metal plate with an etching solution that does not corrode it to form through holes in the base metal plate is taken.

Further, in the invention of claim 2, (a). A step of forming a resist pattern by selectively covering the through hole forming portions on both sides of the base metal plate, and (b). On the exposed portion of the base metal plate where the pattern is not applied,
With respect to etching resistance, a step of forming a dissimilar metal layer different from the base metal plate by electroforming, (c). A step of removing the resist pattern, and (d). Using the residual dissimilar metal layer as a mask. , A step of forming a through hole in the base metal plate by etching the base metal plate with an etching solution that does not substantially corrode the dissimilar metal layer.

As the base metal plate, for example,
Metals such as copper and copper alloys, aluminum and aluminum alloys, iron and iron alloys, which can be etched by using the following dissimilar metals as a masking material, can be used. Further, as the above-mentioned dissimilar metal, any metal that is not etched by an etching solution for the base metal, for example, commonly used plating such as copper, nickel, silver, gold, platinum, chromium, palladium, tin, lead, etc., can be used. Any material can be used. The thickness of the base metal plate and the dissimilar metal layer is not particularly limited, but the thickness of the dissimilar metal layer to be electrodeposited can be usually about 20 to 300 μm.

[0015]

In the present invention, since the patterning of the dissimilar metal layers formed on both surfaces of the base metal plate is performed by electroforming rather than etching, the contour portion of the through hole in the dissimilar metal layer outside the metal perforated plate. Becomes sharp (almost right angle). Further, since the etching is performed only on the base metal plate, the processing speed is high and the perpendicularity of the through hole is good.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. First, as shown in FIG. 1, a base metal plate (for example, a phosphor bronze plate) 21 is washed and dried, then resist is applied to both front and back surfaces, and then exposed through a mask (not shown) and developed. A resist pattern 22 is formed so as to selectively cover the through-hole forming portions on both surfaces.

A different metal (for example, nickel) layer 23, which is different from the base metal plate 21 in terms of etching resistance, is electroplated on the exposed portion of the base metal plate 21 on which the resist pattern 22 is not deposited. Formed by (Fig. 2
reference).

Next, using a stripping solution, a resist pattern 2 is formed.
2 is removed (see FIG. 3). When the resist pattern 22 is removed, the dissimilar metal (for example, nickel) layer 23 remains as a pattern opposite to the resist pattern, and the phosphor bronze covered with the resist pattern is exposed.

Then, the dissimilar metal layer 23 is used as an etching resist, and the dissimilar metal layer 23 is used as a mask for etching with an etching solution that does not substantially corrode the base metal plate 21 to dissolve the through holes 24. The obtained metal perforated plate has the same precision as that obtained by the electroforming method, and the production speed thereof can be significantly shortened as compared with the conventional electroforming method.

As described above, since the through hole of the dissimilar metal layer 23 is formed by electroforming and is not etched at all, the contour 23a can form a right angled shape with high precision. .. In the above embodiment, the resist pattern 22 is symmetrically formed on both front and back surfaces of the base metal plate 21.
According to the shape of No. 4, the size of the hole of the resist pattern 22 on one surface may be made larger than that of the other, and the above-mentioned processing step may be performed (see FIG. 5).

In the above embodiment, the case where phosphor bronze is used for the base metal plate and nickel is used for the dissimilar metal layer has been exemplified, but various combinations can be considered depending on the purpose of use of the product. For example, as the base metal, it is possible to use metals such as copper and copper alloys, aluminum and aluminum alloys, iron and iron alloys, which can be etched using the following dissimilar metals as a masking material. Further, as the dissimilar metal, a commonly used plateable material such as copper, nickel, silver, gold, platinum, chromium, palladium, tin, or lead can be used.

Thus, according to the present invention, it is possible to form fine or highly precise through-holes, which are difficult to achieve by the conventional method, and the thickness of the dissimilar metal layer serving as the outer surface is increased. However, since the sharpness of the peripheral portion of the through hole is not lost, it is possible to manufacture a perforated plate for various applications. Further, the present invention comprises a three-layer metal plate in which different metal layers are laminated on both sides of the base metal plate, but the base metal plate itself is formed in multiple layers with a metal having the same kind of properties as the base metal. It may be one.

(Embodiment 1) Next, the production of a metal mask for screen printing as an example of a metal perforated plate using this production method will be described in detail. 300 mm x 300 mm
After degreasing and washing a 0.1 mm thick phosphor bronze plate, a photosensitive resin (resist) was applied on both sides and dried, and then a masking film was placed thereon and exposed to ultraviolet light. After the exposure, the film was peeled off and developed with a predetermined developing solution to form a resist pattern having a thickness of 50 μm. Next, nickel plating was performed in a normal nickel sulfamate plating bath so that the thickness of each of the upper and lower surfaces was 50 μm. This plating time is about 5 hours (it takes about 30 hours in the case of only the conventional electroforming method, which is a 1/6 time reduction). Then, the resist pattern was stripped off with a stripping solution to expose the phosphor bronze plate in the through hole forming portion. Furthermore, the exposed phosphor bronze plate portion is etched for about 10 minutes with a mixed solution of ammonium persulfate and ammonia water that does not corrode nickel at all, and a through hole having a pitch of 0.2 mm, a hole width of 0.15 mm, and a total height of 0.2 mm is formed. It was possible to produce a screen-printed metal mask consisting of three layers that were formed. The formed through holes of the metal mask were sharp with the contours on both the front and back sides being right angles, the verticality of the through holes was smooth, and the ink removal property was good.

[0024]

As described above, according to the metal perforated plate and the method for manufacturing the same of the present invention, different metal layers are formed on both surfaces of the base metal plate by electroforming, and the different metal layers are used as masks. Since only the base metal plate is perforated by etching, regardless of the thickness of the metal perforated plate, the through hole of the finally obtained metal perforated plate has a sharp contour (almost right angle). Also, the verticality of the through hole becomes good. As a result, according to the present invention, it is possible to provide a large number of through holes with a fine pattern, that is, a short pitch, which has been difficult to achieve by the conventional method, and the same processing is performed even if the thickness of the dissimilar metal layer serving as the surface is large. It has become possible. Moreover, the processing time can be greatly shortened as compared with the case where only the electroforming method is used, which is extremely useful. The metal porous plate and the method for producing the same of the present invention can be used when forming a through hole in a metal plate without limiting the application of the metal porous plate.

[Brief description of drawings]

FIG. 1 is a first metal perforated plate shown as an embodiment of the present invention.
It is sectional drawing which shows a process.

FIG. 2 is a sectional view showing a second processing step of the same.

FIG. 3 is a sectional view showing a third processing step of the same.

FIG. 4 is a sectional view showing a fourth processing step of the same.

FIG. 5 is a cross-sectional view showing through holes having different sizes of upper and lower holes.

FIG. 6 is a cross-sectional view of a porous metal plate obtained by a conventional etching method.

FIG. 7 is a first method of manufacturing an improved conventional porous metal plate.
It is sectional drawing which shows a process.

FIG. 8 is a cross-sectional view showing a second processing step of the same.

FIG. 9 is a sectional view showing a final processing step of the same.

[Explanation of symbols]

 21 Base Metal Plate 22 Resist Pattern 23 Dissimilar Metal Layer 24 Through Hole

Claims (2)

[Claims] 1. A resist pattern is formed so as to selectively cover through-hole forming portions on both surfaces of a base metal plate,
A different metal layer, which is different from the base metal plate in terms of etching resistance, is formed on the exposed portions of both sides of the base metal plate on which the resist pattern is not deposited by electroforming, and the resist pattern is removed and left. A perforated metal plate, characterized in that the base metal plate is etched by using the dissimilar metal layer as a mask to etch the base metal plate with an etching solution that does not substantially corrode the dissimilar metal layer. .. 2. A step of forming a resist pattern by selectively covering the through-hole forming portions on both sides of the base metal plate, and a step of resisting the exposed portion of the base metal plate on which the resist pattern is not applied. With respect to the etching property, a step of forming a dissimilar metal layer different from the base metal plate by electroforming, a step of removing the resist pattern, and a step of substantially removing the dissimilar metal layer using the remaining dissimilar metal layer as a mask A method for producing a perforated metal plate, comprising the step of etching the base metal plate with an etching liquid that does not corrode to form a through hole in the base metal plate.