JP3191383B2 - Printing plate manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printing plate, and more particularly to a method for manufacturing a printing plate suitable for precision printing for use in printing and manufacturing printed wiring boards and various electric elements.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for the introduction of a printing method as a manufacturing method that is cheaper and more efficient than conventional photolithography methods in the manufacture of various electric elements and the like. As a printing plate used for printing in such a field, a photosensitive resin method which has been widely used in the past, and a printing plate manufactured by a corrosion method and the like have been used. As the demands for improvement and the like increase, it becomes difficult to satisfy such demands in the above-mentioned method due to the limitation of the resolving power.

As one method of manufacturing a high-precision printing plate for solving such a problem, a resist pattern is formed on a conductive substrate such as a metal by a photolithography method, and a resist film having a thickness less than the thickness of the resist is formed on an exposed portion of the substrate surface. A method is known in which a metal plating is applied to the film thickness of the above, and then the resist is removed.

[0004]

Specifically, the photolithography method in the above method is to apply a resist uniformly on a substrate, and to subject the resist to close contact exposure with a photomask using an ultraviolet ray or the like, followed by development. .

However, in this method, even in the case of close contact exposure, the interface between the substrate and the resist is separated from the photomask surface by at least the thickness of the resist. Therefore, the intensity of light reaching the interface is reduced due to light absorption and scattering. Therefore, in the exposed portion having a small area as compared with the resist film thickness, the vicinity of the interface is likely to be underexposed, so that the resist of the portion does not come off during development if it is a positive type, and if it is a negative type, There has been a problem that the resist in that portion is melted to cause a pattern defect.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method of manufacturing a printing plate with high precision without losing a fine image pattern.

[0007]

According to the present invention, there is provided a printing plate manufacturing method comprising a pattern-shaped exposure line shielding means which has at least a surface on which a convex portion is desired to be conductive, and which can transfer and expose a pattern from the back surface to the front surface during exposure. The above object is achieved by sequentially performing the following steps (A), (B), (C) and (D) on the printing plate base material. (A) A step of providing a resist on the printing plate substrate surface. (B) A step of patterning the resist by exposing and developing from the back surface of the printing plate substrate. (C) a step of plating the removed portion of the resist to a thickness equal to or less than the thickness of the resist pattern. (D) removing the resist pattern.

As the resist, any resist can be used according to the required specifications of the printing plate to be manufactured. The resist may be a positive resist or a negative resist. In the case of a positive resist, there is a difference in that the pattern-like exposure line shielding means is provided on a surface other than the surface where the projection is desired, and in the case of the negative resist, the pattern-like exposure line shielding means is provided on the surface where the projection is desired. However, when a negative resist is used, it is necessary to use a conductive material as the pattern-shaped exposure line shielding means, or to remove the resist after developing the resist.

[0009] Exposure rays may be ultraviolet rays, X-rays or other radiation. The material, resist, and the like that are used as the pattern-like exposure line blocking means differ depending on the difference in the exposure line.

[0010] The pattern-shaped exposure line shielding means can be realized by using the surface itself as a shielding film or providing a shielding film on the surface. Also, the surface of the printing plate substrate may be subjected to a shielding treatment by chemical or physical treatment without being provided separately from the printing plate substrate as a shielding film. When a shielding film is provided on the surface, a configuration in which the surface is a conductive film that transmits light for exposure can be adopted. In short, it is important that the pattern-shaped exposure line shielding means has a positional relationship that allows accurate exposure of the resist by backside exposure, and it is sufficient if it is near the surface. For this reason, the object of the present invention can be achieved without directly contacting the resist or even in contact with the resist via a transparent conductive film or the like.

Regarding the printing plate substrate, even if the printing plate substrate itself is not conductive, it is sufficient that a conductive film is provided on the surface. If there is no closed pattern that cannot be supplied with electricity, it is sufficient that only the portion serving as the plate is conductive.

When the conductivity of the printing plate base material surface is realized by a conductive film, for example, a Nesa film, an ITO film or the like can be applied, and is formed by a coating method or a sputter deposition method.

When the patterned exposure line shielding means is realized by a light-shielding thin film pattern, the material may be an organic substance such as a black resist when the exposure line is ultraviolet rays, but usually aluminum, silver, nickel, chromium. Are preferred. When the exposure line is an X-ray, a material containing at least a heavy metal such as lead, platinum, tantalum, and tungsten is preferable. As the patterning method, any conventionally known method such as a photoetching method, a lift-off method, a mask evaporation method, and a transfer method can be applied. The film thickness is preferably about 1 μm or less to prevent coating unevenness of a resist to be applied later, and in the case of metal, it is usually about 50 to 200 nm.

The order of lamination of the conductive film and the light-shielding thin film pattern may be either on the printing plate base material side or may be omitted if the printing plate base material itself is conductive. However, the printing plate base material and the conductive film need to have at least sufficient transparency to expose the resist to exposure light.

As a means for providing a resist, a spin coating method, a roll coating method, a spray coating method, a dip coating method, or the like can be applied.

In the exposure step, since backside exposure is performed, operations such as vacuum contact and registration are not required at all. However, the light used for exposure is preferably parallel light or light close thereto.

The pattern-shaped exposure line light shielding means is generally performed by providing a metal layer having a thickness equal to or less than the thickness of the resist on the surface of the printing plate substrate or in a pattern. Although the material of the plating layer is not particularly limited, copper, nickel, chromium, iron, and the like are preferable in consideration of convenience of metal plating and suitability as a printing plate, and a plurality of kinds thereof may be compounded or laminated. Finally, when the resist is removed, a printing plate is obtained. The light-shielding thin film pattern may be a finished product of a printing plate while being left as in the embodiment described later,
If necessary, the light-shielding thin film pattern may be removed.

[0018]

According to the method of manufacturing a printing plate of the present invention, a resist is applied to the surface of the printing plate substrate and then exposed from the back surface of the substrate to pattern the resist. A sufficient exposure dose can be applied to the resist near the interface.

As a result, there is a phenomenon in the positive resist that pattern loss due to insufficient solubility can be prevented. Thereby, a printing plate faithful to the original plate can be manufactured.

In the case of a negative resist, there is a phenomenon that pattern loss due to insufficient curing can be prevented. Thereby, a printing plate faithful to the original plate can be manufactured.

The portion where the resist is not exposed is insoluble in the positive resist, and the pattern remains after development. The negative resist does not cure and is washed away during development.

When the exposure line is ultraviolet light, the exposure line pattern shielding means is a means for making the ultraviolet light impermeable, and the resist is an ultraviolet-sensitive resist. Only the ultraviolet-sensitive resist in the portion where the pattern shielding means is not provided causes a photoreaction, and an appropriate resist pattern can be formed.

When the exposure line is an X-ray, the exposure line pattern shielding means is a means for making the X-ray opaque, and the resist is an X-ray sensitive resist. Upon exposure, only the X-ray sensitive resist in a portion where the exposure line pattern shielding means is not provided causes a photoreaction, and an appropriate resist pattern can be formed.

When a shielding film is used as the exposure line pattern shielding means, either the shielding film or the conductive film can be used.

[0025]

【Example】

<Embodiment> Hereinafter, the present invention will be described in detail with reference to the drawings. 1 to 6 are sectional views showing one embodiment of a printing plate manufacturing method of the present invention in the order of steps.

On a surface of a glass printing plate substrate 1 whose surface is polished smoothly, a transparent ITO film 2 having a thickness of 150 nm
Was formed as a conductive film by sputtering.

An aluminum film having a thickness of 200 nm is formed thereon by evaporation, and a positive resist (A Hoechst A)
Z1350) to a film thickness of 1.5 μm, mask exposure, and development with a dedicated developer (AZ developer manufactured by Hoechst).
The exposed aluminum film is dissolved and removed with an ammonium chloride solution, and the remaining resist film is dissolved and removed with acetone. As a result, a patterned aluminum film 3 as shown in FIG. 1 was formed as a patterned exposure shielding means.

Next, the ITO film 2 and the patterned aluminum film 3
A positive resist (AZ4903 manufactured by Hoechst) was applied as a resist 4 on the surface of the printing plate substrate 1 provided with the above by a spin coating method to a film thickness of 25 μm (FIG. 2).

Thereafter, the entire surface of the printing plate substrate 1 is exposed by irradiating the back surface of the printing plate substrate 1 with ultraviolet rays in parallel. (Fig. 3)

The resist 4 was developed with a special developing solution (AZ400K developer, Hoechst) to obtain a resist pattern. A 15 μm copper layer and a 5 μm chromium layer, which are plating layers 5 having a thickness equal to or less than the thickness of the resist 4, are applied to a portion where the resist 4 has been removed by electroplating, respectively. They were provided sequentially in a sulfuric acid bath (FIG. 5). Finally, the resist was dissolved and removed with a sodium hydroxide solution to obtain a printing plate 6 (FIG. 6). The resolving power of the printing plate 6 was about 4 μm at the convex portion and about 2 μm at the concave portion.

<Comparative Example> A positive resist (AZ4903 manufactured by Hoechst) was applied to a thickness of 25 μm on the surface of a copper plate whose surface was polished smoothly, and the same photomask as that used in the above example was used. Mask exposure was performed, and a printing plate was obtained in the same manner as in the above example. The resolving power of this printing plate was about 8 μm at the convex part and about 5 μm at the concave part, and the pattern having a size smaller than that was almost lost.

[0032]

As described in detail above, according to the printing plate manufacturing method of the present invention, a printing plate which is excellent in resolution and has high resolution and is faithful to the original plate can be produced with high precision even in a fine pattern. Can be manufactured.

[0033]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view before a resist is provided during a process according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view after a resist is provided during a process according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view at the time of exposure during a process according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view after development during a process according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view after plating during the steps of one embodiment of the present invention.

FIG. 6 is a cross-sectional view after the process of the embodiment of the present invention is completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printing plate base material 2 ... ITO film 3 ... Patterned aluminum film 4 ... Resist 41 ... Resist exposure part 5 ... Plating layer 6 ... Printing plate

──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41C 1/00 G03F 7/00

Claims (11)

(57) [Claims] 1. A printing plate substrate having a pattern exposure line blocking means having at least a conductive surface having a desired convex portion and capable of transferring and exposing a pattern from the back surface to the front surface during exposure. B) A method for producing a printing plate, comprising the steps of (C) and (D). (A) A step of providing a resist on the printing plate substrate surface. (B) A step of patterning the resist by exposing and developing from the back surface of the printing plate substrate. (C) a step of plating the removed portion of the resist to a thickness equal to or less than the thickness of the resist pattern. (D) removing the resist pattern. 2. The method according to claim 1, wherein the resist is a positive resist. 3. The method according to claim 1, wherein the resist is a negative resist. 4. The method according to claim 1, wherein the exposure line is an ultraviolet ray, and the pattern exposure line blocking means is a pattern ultraviolet ray shielding means .
4. The method for producing a printing plate according to any one of 3 . 5. The exposure line is an X-ray, claims 1-3 patternwise exposing ray shielding means is a patterned X-ray shielding means
The method for producing a printing plate according to any one of the above. 6. The method for producing a printing plate according to claim 1, wherein the pattern exposure line shielding means comprises a shielding film. 7. A printing plate substrate is conductive of claims 1-6
The method for producing a printing plate according to any one of the above. 8. The method according to claim 1, wherein the surface of the printing plate substrate is conductive .
7. The method for producing a printing plate according to any one of 6 . 9. The method for producing a printing plate according to claim 8, wherein the surface of the printing plate base material is a light-transmitting conductive film. 10. The printing plate manufacturing method according to claim 9, wherein the surface of the printing plate base material is an exposure-ray-transmitting conductive film, and a patterned exposure-line shielding film is provided thereunder. 11. The method for producing a printing plate according to claim 9, wherein the surface of the printing plate substrate is a light-transmitting conductive film, and a patterned exposure line shielding film is provided on the surface of the printing plate substrate.