JPH05257270A - Production of printing plate - Google Patents

Abstract

PURPOSE:To obtain the process for production of the printing plate having precise patterns which decreases the defects of the plates and can prevent the generation of defects in printed matter. CONSTITUTION:The printing plate is obtd. by setting the film thickness of a resist 3 to be provided on a substrate 1 smaller than twice the pattern width to make the resist 3 hardly peeled from the substrate 1 and applying a metal plating on the surface of the substrate 1 contg. the resist 3, then peeling the resist from the substrate 1. More specifically, exposing directions are made plural and all the parts higher than twice the pattern width are exposed in the case of a positive resist and the exposing directions are made plural and the parts higher than twice the pattern width are prevented from being irradiated with all of the exposing the light in the case of a negative resist bat the time of exposing the rear surface, by that such resist 3 is formed. As a result, the resist 3 on the substrate 1 is hardly peelable from the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a printing plate, and more particularly to a method for producing a printing plate suitable for producing an intaglio printing plate used for precision printing on a printed wiring board, various electric elements and the like.

[0002]

2. Description of the Related Art In recent years, in the manufacture of various electric elements,
There is an increasing demand for introduction of a printing method as a manufacturing method which is cheaper and more efficient than the conventional photolithographic method. As a printing method used for printing in such a field, an intaglio type having a wide degree of freedom of usable ink is most promising, and as a method for producing the printing plate, it responds to demands such as pattern miniaturization and dimensional accuracy improvement. Therefore, in place of the widely used conventional photosensitive resin method or chemical corrosion method, a method has been proposed in which a resist pattern is formed on the substrate surface by a photolithography method and then metal plating is applied (Japanese Patent Application No. Hei 10-135242). 2-11692).

Further, in the above method, as a method of preventing defects of the printing plate due to poor resolution of the resist in the fine pattern portion, the resist is applied to a transparent substrate having a light-shielding thin film pattern on its surface, and then the substrate is There is proposed a method of exposing and developing from the back surface of the substrate to pattern the resist, and then performing metal plating on the surface of the substrate including the patterned resist and then peeling it off (see Japanese Patent Application No. 3-211080). ..

[0004]

In the production of the above-mentioned various electric elements and the like, defects in print patterns, pinholes, etc. are defects that impair the function of the product, and therefore it is required to eliminate them as much as possible. In intaglio printing, it is generally known that the deeper the plate depth is, the less defects such as pattern defects and pinholes are generated, and the plate depth threshold at which the defects are tolerable is deeper as the cell width is wider.

According to the method for producing a printing plate in which the resist pattern on the substrate is metal-plated as described above, when the produced printing plate is viewed as an intaglio plate, its plate depth is defined by the resist film thickness regardless of the cell width. Since it is a constant value, it is necessary to set the plate depth sufficient for suppressing pattern loss and pinhole generation for the widest image line in the print pattern.

However, when there is an extreme difference in the pattern width corresponding to the image line of the print pattern, if the resist film thickness is set to the plate depth required for the widest image line among them, the small image line will have the difference. The ratio of the film thickness to the pattern width becomes large, and the contact area between the resist film and the substrate becomes smaller than the film thickness. In such a contact area, the resist cannot withstand external pressure. There is a problem that it is easy to peel from the substrate due to the fluid pressure of 1), the stress of the metal plating film during the metal plating process, and the like, and plate defects are likely to occur.

This problem tends to occur particularly when the ratio of the film thickness to the pattern width corresponding to the image line is 2 or more, although it depends on the conditions. On the other hand, in order to prevent the occurrence of the above-mentioned print pattern loss and pinholes, it is generally necessary that the ratio of the plate depth to the pattern width corresponding to the image line is at least 1/10, depending on the conditions. Is. Therefore, it is difficult to prevent the plate defect and the printed matter defect at the same time when the image line width includes an image line having a maximum difference of 20 times or more.

[0008]

SUMMARY OF THE INVENTION In view of the above problems, the present invention prevents plate defects and prevents printed product defects by changing the film thickness of a resist pattern to be metal-plated in accordance with the pattern width. It aims to achieve both prevention and prevention.

As a concrete means thereof, in the method of manufacturing a printing plate, the surface of the substrate, on which the patterned resist is formed, is subjected to metal plating, and then the resist is peeled off. That is, the thickness is smaller than twice the pattern width.

Particularly, in the invention of claim 2, the resist is patterned by applying the resist to a transparent substrate having a light-shielding thin film pattern on its surface, and then exposing and developing from the back surface of the substrate to pattern the resist. After that, after performing metal plating on the surface of the substrate including the patterned resist, the resist is peeled off, and the exposure direction has a plurality of directions, and any two of the plurality of exposure directions are exposed. That is, when they face each other across the pattern width, they intersect at a height lower than twice the pattern width.

In this case, if the incident angles are different from each other by 30 degrees or more, the above condition can be easily satisfied. Also, as for the exposure direction, the larger number can correspond to various pattern width directions, and the above condition can be easily satisfied.

According to the third aspect of the invention, the exposure direction is provided in a plurality of directions by changing the incident angle with respect to the substrate and performing a plurality of times. In this case, if the incident angles differ from each other by 30 degrees or more, the above conditions can be easily satisfied.

Further, according to the invention of claim 4, the exposure directions are provided in plural directions by changing the incident angle with respect to the substrate. In this case, if the maximum angles of incidence differ from each other by 30 degrees or more, the above conditions can be easily satisfied.

According to a fifth aspect of the present invention, a plurality of exposure directions are provided by simultaneously irradiating from a plurality of light sources having different incident angles with respect to the substrate.
In this case, if the incident angles differ from each other by 30 degrees or more, the above conditions can be easily satisfied.

Further, in the invention of claim 6, the exposure is carried out by diffused light so as to have a plurality of directions. In this case, if the distribution of the incident angle reaches 30 degrees or more, the above condition can be easily satisfied.

According to the inventions of claims 7 to 8,
The action differs depending on whether the resist is a positive resist or a negative resist, but as a final effect, the above effects can be exhibited in any case.

[0017]

According to the method for producing a printing plate of the present invention, the film thickness of the resist changes according to the image width of the resist, and the film width becomes thin when the image line width is narrow and the film becomes large when the image line width is wide. Since the thickness can be increased, it is possible to prevent a plate defect caused by the plating resist peeling from the substrate and a print defect caused by insufficient plate depth.

Specifically, when any two of the plurality of exposure directions face each other across the pattern width, they intersect each other at a height lower than twice the pattern width. When exposure is performed from a plurality of directions, the resist in a portion higher than twice the pattern width is exposed because it is included in either of the exposure directions at both ends of the pattern in the case of a positive resist. Is included only in one of the exposure directions at both ends, and the irradiation density is reduced.

Whether the exposure is performed multiple times by changing the incident angle with respect to the substrate, the exposure is performed while changing the incident angle with respect to the substrate, or the exposure is performed by simultaneously irradiating from a plurality of light sources with different incident angles with respect to the substrate. Alternatively, there are various methods such as exposing the substrate with diffused light. In any method, the exposure is performed by irradiating at least lights having different incident angles to the substrate.

Then, the photosensitive portion in the resist film on the substrate spreads away from the surface of the substrate where the light-shielding thin film pattern exists. If the resist is positive type, the photosensitive portion is entirely melted, and if the resist type is negative, the light beam spreads. Since the irradiation density decreases, the upper layer becomes incompletely cured.

As a result, the cross-sectional shape of the resist film after development becomes narrower as it goes away from the surface of the substrate and becomes wedge-shaped in a small image area to be mechanically stable. Peeling due to stress or the like is unlikely to occur, and the occurrence of plate defects can be prevented.

Moreover, since a sufficient plate depth determined by the resist coating thickness can be obtained in the wide image area, it is possible to prevent defects in the printing pattern and defects in the printed matter such as pinholes.

[0023]

EXAMPLES In the production of the printing plate of the present invention, the conditions other than the exposure step and the conditions such as materials are described in Japanese Patent Application No.
It is omitted here because it is described in detail in No. 2111080, and only the exposure process will be described in detail. Here, only an example in which a positive type resist is used will be described, but as described in the section of the action, the resist may be a negative type.

At the stage of entering the exposure step, a light-shielding thin film pattern 2 and a resist 3 are provided on the surface of the transparent substrate 1 (see FIG. 1A). On the other hand, from the back side of the board,
An angle from the normal to the substrate surface (hereinafter referred to as the incident angle)
The resist 3 is irradiated with radiation such as ultraviolet rays (see FIG. 1B), and then from the opposite angle (see FIG. 1C). When this is developed, a resist film having a wedge-shaped cross section, which is thinner than the applied resist film thickness, remains in the wide image area (see FIG. 1D).

A printing plate can be obtained by metal plating according to a conventionally known method and peeling from the substrate (not shown).

It should be noted that if the print image pattern is a stripe pattern, the above-mentioned two times of exposure are sufficient, but in the general case, the incident angle is two-dimensionally changed and the exposure is performed a plurality of times such as four times and six times. May be done. The incident angle may be appropriately determined according to the desired resist cross-sectional shape, but is preferably at least 15 degrees or more, and generally in the range of 30 degrees to 60 degrees.

Instead of performing the exposure a plurality of times as described above, the incident angle may be changed by a method such as moving the light source or the substrate during the exposure (incident in FIG. 1 (b) and FIG. 1 (c)). It is also possible to obtain the same effect by one exposure by a method such as changing the angle) or using a plurality of light sources (see FIG. 2). As the latter method, a light source may be a light source which is obtained by separating light from a single light source into a plurality of locations by separating the light with a reflecting mirror or an optical fiber.

Diffused light can also be used as a simpler method. FIG. 3 shows an example in which the scattering plate 4 is used.
As the material, a usual ground glass, a ceramic fired body, a milky white plastic, or the like may be used, but a polymer liquid crystal or the like is convenient because the distribution of the scattering angle can be controlled.

Besides, a method using a scattering reflector or a multi-faceted reflector, a method using a planar light-emitting body, and the like are also applicable. The distribution of the scattering angle is preferably at least 30 degrees or more, and particularly 60 to 120 degrees (incident angle distribution ± 3
0 degree to ± 60 degrees) is preferable.

As a result, in any resist, the ratio of the film thickness to the line width was between 2: 1 and 1:10. As a result, the resist thus formed has no defects in the next metal plating process. As a result, the number of defects in printed matter was significantly reduced as compared with the conventional one.

[0031]

According to the method for producing a printing plate of the present invention, since the film thickness of the resist which forms the plate cell is changed depending on the image line width, a small image line is peeled off from the substrate in the developing process or the metal plating process. As a result, there is no plate defect and the plate depth can be made sufficiently deep in the wide image area.
It has an excellent effect that it is possible to prevent the occurrence of pattern defects and printed matter defects such as pinholes during printing.

Further, it is possible to provide a means for easily implementing the above invention by controlling the light source using the backside exposure technique.

[0033]

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing an exposure process in the order of (a) to (d) in the method for producing a printing plate of the present invention.

FIG. 2 is a cross-sectional view of another method for manufacturing a printing plate of the present invention.

FIG. 3 is a cross-sectional view of another method for manufacturing a printing plate of the present invention.

[Explanation of symbols]

 1 ... Substrate 2 ... Light-shielding thin film pattern 3 ... Resist 31 ... Resist exposure part 4 ... Scattering plate

Claims (8)

[Claims] 1. A metal plating is applied to the surface of the substrate on which a patterned resist is formed,
A method for producing a printing plate, comprising removing a resist, wherein the thickness of the patterned resist is smaller than twice the pattern width. 2. The patterning of the resist comprises applying a resist to a transparent substrate having a light-shielding thin film pattern on the surface, exposing and developing from the back surface of the substrate to pattern the resist, and then patterning the resist. After performing metal plating on the surface of the substrate including, it is performed by peeling the resist, the exposure direction has a plurality of directions, any two of the plurality of exposure directions the pattern width is sandwiched. The method for producing a printing plate according to claim 1, wherein, when facing each other, they intersect at a height lower than twice the pattern width. 3. The method of manufacturing a printing plate according to claim 2, wherein the exposure direction is provided in a plurality of directions by changing the incident angle with respect to the substrate a plurality of times. 4. The method of manufacturing a printing plate according to claim 2, wherein the exposure direction is provided in a plurality of directions by changing the incident angle with respect to the substrate. 5. The method of manufacturing a printing plate according to claim 2, wherein the exposure directions are provided in plural directions by simultaneously irradiating from a plurality of light sources having different incident angles with respect to the substrate. 6. The method of manufacturing a printing plate according to claim 2, wherein the exposure is performed in a plurality of directions by performing diffused light. 7. The method of manufacturing a printing plate according to claim 1, wherein the resist is a positive resist. 8. The method of manufacturing a printing plate according to claim 1, wherein the resist is a negative resist.