JP2935851B2 - Fine pattern printing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a printing method of a fine pattern in which a fine pattern is formed by a printing means, for example, a fine resist pattern such as a fine circuit or an element pattern supplied to an electronic component. The present invention relates to a printing method suitable for forming a high-precision and mass-produced.

[Problems to be solved by conventional technology and invention]

2. Description of the Related Art Conventionally, printing means such as a screen printing method and an offset printing method have been widely used for forming a circuit pattern on a printed wiring, glass or ceramic plate, or forming a resist pattern for etching a metal plate. However, these printing means have a relatively large image width (200 μm
As described above, it is suitable for forming a pattern, but it is not suitable for forming a fine pattern with an image line width smaller than that. In addition, the pattern to be printed is deformed due to the influence of the fluidity of the ink, the pressure of the plate, etc., and a portion of the ink remaining on the plate without transferring, and the like.
There is also a disadvantage that the reproducibility of the print pattern is poor.

For example, in the screen printing method, an ink shielding mask is formed on a mesh screen, a non-mask portion of the mask is formed into a desired pattern, and ink is passed from the non-mask portion to adhere to a printing medium to perform printing. Although this printing method makes it possible to print a resist pattern with excellent corrosion resistance because it is easy to apply thick ink (thickness of several μm to 20 μm), it is only about 200 μm even with the smallest practical printing line width. Because of the limitations, it was difficult to print a complicated and fine pattern.

The offset printing method is the PS version (Presensitized Plat
e) forming a lipophilic portion and a hydrophilic portion, holding the moisture in the hydrophilic portion to repel the oil-based ink, selectively depositing the ink only on the lipophilic portion, and applying such an ink pattern to the printing medium. This is a printing method, especially for improving printability.
The ink pattern on the PS plate is once transferred to a rubber blanket and then retransferred to a printing medium such as paper. However, in this printing method, a relatively fine image is easily obtained, but the ink film thickness to be printed tends to be as small as about 1 to 2 μm due to the inking method and the two transfer operations. Therefore, there is a disadvantage that a pinhole or disconnection is easily generated in the printed image. Also, in this printing method, various measures have been taken to increase the thickness of the ink film and form a fine pattern with excellent corrosion resistance.However, when the film thickness is increased, the printed image becomes thicker, and eventually, Where 100-200μ
Printing with a line width of about m was the limit.

Therefore, in the above-mentioned printing method, even if an attempt is made to use fine line printing, printing with a line width of about 100 to 200 μm is basically the limit, and if a pattern with a smaller line width is to be printed, the ink film thickness is also reduced at the same time. Therefore, the method cannot be applied particularly to the formation of a fine pattern requiring corrosion resistance such as a resist pattern.

As described above, it is difficult to form a fine pattern by the printing method, and the pattern to be printed cannot be always faithful to the plate pattern, and the reproducibility is insufficient. Generally had to rely on photolithography. However, this photolithography is capable of forming an extremely fine pattern, but has disadvantages in that the process is complicated, the productivity is low, and the cost is high as compared with printing means.

On the other hand, there is an intaglio printing method as a printing means that can be configured to have a printing plate having relatively thin lines and a large printing film thickness. In this printing method, an image concave portion is formed on a copper plate or the like by an engraving method or an engraving method, a hard ink is rubbed into the concave portion, a non-image portion of the ink is wiped off, and then the printing paper is pressed onto the copper plate and strongly pressed. This is for printing. The reason for the strong pressure is that the ink rubbed in the recesses is located at a position depressed from the plate surface, so that the ink surface and the printing material surface are forcibly brought into contact with each other by forcibly pressing on a flexible printing material such as paper. This is to transfer the ink to the printing portion.

However, although the conventional intaglio printing method is more suitable for fine line printing than the screen printing method and the offset printing method described above, printing on substrates made of highly rigid plastic, glass, ceramic, metal, etc. is not possible. There is a major problem that is almost impossible.

The present invention has been made in view of the above-described problems, and can form a fine pattern having a line width that is extremely thinner than that of a conventional printing method and an ink film thickness that is appropriate. It is an object of the present invention to provide a method for printing a fine pattern that can be formed accurately, sharply, efficiently and inexpensively on various printing materials.

[Means for solving the problem]

That is, the present invention provides: (1) a curable ink is applied to a printing intaglio having a fine pattern concave portion to be a printing image portion, and ink other than the concave portion is removed by a doctor, and the ink is applied only to the concave portion. Filling, or applying a hardening ink to a printing lithographic plate made by making a fine pattern plate portion that becomes a printing image portion, and patterning by applying the ink only to the pattern plate portion, A method for printing a fine pattern, which comprises transferring an ink on an intaglio or planographic plate to a printing medium after curing the ink with heat or radiation.

(2) The printing method according to claim 1, wherein after the adhesive or tacky layer is provided on the printing medium in advance, the cured ink is transferred to the printing medium via the layer.

(3) After patterning the curable ink on the intaglio or lithographic plate, or after curing the patterned ink, provide an adhesive or tacky layer on the plate surface, and then cure through the layer. 2. The printing method according to claim 1, wherein the subsequent ink is transferred to a printing medium.

(4) The printing method according to any one of claims 2 and 3, wherein the printing medium is made of metal, ceramics, glass, or plastic and has rigidity.

(5) The printing method according to any one of claims 2 to 4, wherein after transferring the cured ink, the adhesive or tacky layer in the portion of the printing medium where the cured ink layer does not exist is removed.

It is the gist.

[Effect] The printing method of the present invention is capable of patterning a curable ink into an extremely fine and fine pattern having an appropriate film thickness by using an intaglio or planographic plate as a plate, and a curable ink patterned in such a manner. After sufficient curing, i.e., to make the ink non-fluid and to keep the pattern shape on the plate as it is, and then transfer the cured ink to the printing medium. Printing can be performed on a printing medium without deforming the cured ink layer composed of the pattern.

Next, the present invention will be described with reference to the drawings in the order of printing steps.

FIG. 1 shows an example of each step of the printing method of the present invention. FIG. 1A shows a plate 1 for printing used in the present invention. As the plate 1, an intaglio plate as shown or a planographic plate (not shown) is used. The plate 1 is not limited to a flat plate as shown, but may be a cylindrical plate wound around a rubber roller or the like, for example.

When the printing plate 1 is an intaglio, the intaglio 1 has a concave portion 2 serving as a printing image.
When the plate 1 is a planographic plate, a pattern plate portion corresponding to the concave portion 2 is formed on the planographic plate. The method of forming the concave portion 2 is not particularly limited. For example, a metal plate material (generally, copper, a copper alloy, iron, an iron alloy, or another metal such as copper, copper alloy, iron, iron alloy, etc.) formed by a fine cutting method is cut and formed. Alternatively, the plate material can be formed by optically providing a resist mask using photofabrication and then etching. The concave portion 2 has a line width of 5 to 5.
It can be configured as a fine one with a depth of about 50 μm and a depth (plate depth) of about 1 to 10 μm. The plate material may be made of a hard material such as glass or ceramics. Further, in order to increase the hardness of the surface of the intaglio 1, a hard metal such as nickel or chromium may be plated on the plate making surface, whereby the durability when the ink is scraped off by a doctor can be imparted. In forming the pattern plate portion of the planographic printing plate, a known plate making method employed in planographic printing can be applied.

Next, the curable ink 3 is applied to one surface of the printing plate (intaglio) [FIG. 1 (B)]. The ink can be easily applied by immersing the plate in the ink reservoir or by pouring the ink over the plate surface.

The curable ink 3 used in the present invention is a thermosetting type,
It is of an ionizing radiation curing type or the like, and is preferably a solventless type and having a relatively low viscosity. Specifically, commercially available ultraviolet curable inks, electron beam curable inks, infrared (or heat) curable inks and the like can be used, and the present invention can be applied to the known inks as described above. This is a very advantageous point. The basic composition of the ink 3 will be described with reference to an ultraviolet-curable ink. If a photosensitive prepolymer or a monomer and a photopolymerization initiator are used as a binder without using a solvent, a coloring pigment and an appropriate sensitizer or tack may be used. It is composed of ink auxiliaries such as adjusting agents. Further, instead of the usual ultraviolet curable ink, a material appropriately selected from photoresist materials used for semiconductor processing, photoetching and the like may be used. Further, as a lithographic ink, it is not necessary to use a high-viscosity ink as in the conventional lithographic printing method, and a slightly low-viscosity ink can be used. The viscosity of the ink may be adjusted by selectively using a low-viscosity prepolymer or monomer containing a photopolymerization initiator as a binder.

After the ink 3 is applied to the plate 1, if the plate is an intaglio, as shown in FIG. 1 (C), unnecessary ink 3a on the surface of the intaglio 1 is scraped off by a doctor 4 made of a thin metal blade or the like. Then, only the concave portion 2 which becomes a printing image is filled with the ink 3. On the other hand, if the plate 1 is a lithographic plate, the applied curable ink 3 will naturally be deposited only on the pattern plate portion due to the interaction of surface energy between the plate and the ink. In any of the plates, the patterning of the ink 3 is performed at this stage.

Next, as shown in FIG.
The ink is subjected to a curing treatment 5 by heat or radiation to activate the ink, thereby causing a thickening or curing reaction in the concave portion 2 and eliminating the fluidity of the ink to cure (solid).
Ink 3b. Also in the case of a lithographic plate, a thickening or curing reaction occurs on the plate in the same manner as in an intaglio plate, and the patterned ink 3 becomes a cured ink 3b. It is appropriate that the degree of curing of the ink at this time is expressed as a gel fraction and the whole is 90% or more.

After the ink has been cured, the printing medium 6 is superimposed on the plate to bring them into close contact with each other (FIG. 1 (E)), and then the cured ink 3b in the recess 2 of the plate 1 is printed by separating them. The image is transferred onto the body 6 (FIG. 4F) and printed by the printing method of the present invention. In the case of a lithographic printing plate, the cured ink on the printing plate is similarly transferred to the printing medium 6. In this case, the printing medium 6 preferably has flexibility, such as paper or a thin film.

According to the printing method of the present invention, when the printing medium 6 has rigidity such as metal, ceramic, glass, plastic or the like, as shown in FIG. 2 or FIG. (Concave) An adhesive or tacky layer 7 is applied and formed on the printing plate 1 side, and the cured ink 3b is transferred to the printing material 6 with the layer 7 interposed between the printing plate and the printing material (FIG. 4). .
With such a configuration, it is difficult to directly contact the surface of the printing material with the surface of the cured ink, or even if the ink is cured even if the surface is satisfactorily contacted, the cured ink 3b is hardly adhered to the printing material. The instability of the transfer to the printing medium can be eliminated, so that stable and reliable printing can be performed on any rigid printing medium.

When the adhesive or tacky layer 7 is provided on the plate 1 side, the layer 7
Is formed on the entire surface of the plate after the curable ink is patterned in the concave portions 2 and the pattern plate portion, or after the patterned curable ink is cured. The adhesive or pressure-sensitive adhesive forming the layer 7 may be selected from commercially available ones having excellent applicability and low adhesion or adhesion to the plate 1 surface. For example, the bonding / adhesion process can be appropriately selected and used from a solvent activation type, a heat activation type, a pressure activation type, a chemical reaction type and the like depending on a desired process. Among them, a pressure-sensitive type which is a pressure activation type Adhesives (adhesives) and heat-activated adhesives that are heat-activated are preferred.

In the present invention, when printing is performed via the adhesive or sticky layer 7, as shown in FIG. 4, the non-image area where the transferred cured ink layer 3b does not exist on the surface of the printing medium 6 is also used. 7a is present, but if necessary, the layer 7a is removed by appropriate means (FIG. 5). By this removing process, the surface of the printing medium 6 corresponding to the non-image area can be exposed. When the ink layer 3b is formed by etching resist printing, there is a dry etching method using plasma or a wet etching method using an appropriate etching solution. As other removing means, ozone oxidation, radiant energy decomposition, a dissolving removal method using a solvent or a chemical, or the like can be adopted.

The printing method of the present invention having the above configuration can be widely used for applications requiring fine pattern formation. For example, the present invention provides a method for printing a fine pattern on an object to be printed via an adhesive or sticky layer, and then removing the above-described layer in the non-image area, and then optionally exposing the non-image of the object to be printed. It is also very effective in applications where the line portions are etched by dry or wet etching and the cured ink layer (both layers) is removed after the etching.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 A resolution chart was patterned by a photoresist on a polished copper plate having a thickness of 0.15 mm, and etched using a ferric chloride solution to make a plate having a fine pattern having a depth of 3 μm. After the photoresist was removed, the intaglio was wound around a hard rubber roller to form an intaglio roller, and an acrylic-epoxy UV curable ink was applied to the intaglio surface, and then a gravure printing doctor blade was used to remove the intaglio portions other than the intaglio recesses. The ink in the non-image area was scraped off and removed.

Next, ultraviolet light was irradiated toward the intaglio surface to cure the ink filled in the intaglio recesses. After the ink was cured, an acrylic resin-based pressure-sensitive adhesive was applied on the entire surface of the intaglio roller so as to have a coating thickness of 1 μm.

Next, the intaglio roller was placed on a cleaned glass plate and slowly rolled to transfer the cured ink of the intaglio onto the glass plate via the adhesive layer. As a result, it was confirmed that the cured ink in the intaglio recess was completely transferred to the glass plate side without remaining, and a fine image having a line width of 30 μm was printed sharply.

Thereafter, the glass plate was exposed to an oxygen plasma atmosphere for 10 minutes to perform plasma etching. This allows
The cured ink layer is hardly attacked by oxygen plasma due to the presence of the benzene ring due to the epoxy component, and the adhesive layer made of acrylic resin is easily attacked by oxygen plasma. As a result, only the adhesive layer is exposed. The adhesive layer portion of the non-image area was removed.

Through the above steps, a line width of 30 μm and a film thickness of 4
The image of μm (ink layer 3 μm + adhesive layer 1 μm) was clearly printed, and the resolution chart etched on the intaglio was accurately reproduced.

Example 2 The durability of the intaglio used in Example 1 with respect to a doctor ring in which chrome plating was applied to a thickness of 1 μm was enhanced, and an intaglio roller was similarly produced using the intaglio. Next, after applying the novolak-melamine-based thermosetting ink to the intaglio surface,
The ink other than the concave portions on the plate was scraped off with a doctor and removed.

Thereafter, the ink was cured by irradiating far-infrared rays toward the intaglio surface.

On the other hand, a substrate to be printed was prepared in which an acrylic pressure-sensitive adhesive layer was applied in a thickness of 1 μm on the entire surface of a glass plate on which chromium had been vapor-deposited, and the intaglio roller was placed and rolled on the surface. Was completely transferred to the glass plate side. This glass plate was treated with oxygen plasma in the same manner as in Example 1 to remove the non-image area of the pressure-sensitive adhesive layer. During the treatment with oxygen plasma, the cured ink was not attacked by the benzene ring derived from the novolak component.

Through the above steps, a line width of 30 μm, a film thickness of 4 μm, (ink layer 3 μm + adhesive layer 1
μm) or more were printed clearly, and the fine pattern etched in the intaglio was accurately reproduced.

Example 3 A waterless lithographic plate (manufactured by Toray) having a plate depth of 2 μm was used
This was wound around a rubber roller to form a plate copper roller, and an oxidation polymerization type waterless lithographic ink containing an alkyd resin as a main component was applied to the plate surface of the plate cylinder roller. After the ink had a predetermined pattern shape due to the interaction between the plate and the surface energy of the ink, far-infrared rays were applied to the surface of the plate cylinder roller to cure the ink. After the ink was cured, an acrylic resin-based pressure-sensitive adhesive was applied on the entire surface of the plate cylinder roller to a thickness of 1 μm.

Next, the plate cylinder roller was rolled on a glass substrate, and the cured ink was transferred to the glass substrate via the adhesive layer. This glass substrate was exposed to an oxygen plasma atmosphere for 10 minutes,
As a result, the cured ink portion remains without being affected by oxygen plasma due to the benzene ring derived from the alkyd component,
The pressure-sensitive adhesive layer portion made of the acrylic resin was easily attacked by the oxidizing plasma, and as a result, only the pressure-sensitive adhesive layer portion not covered with the cured ink was removed.

Through the above steps, a fine pattern composed of an image having a line width of 30 μm and a film thickness of 3 μm (ink layer 2 μm + adhesive layer 1 μm) was accurately reproduced on a glass substrate.

Example 4 As a plate, a PS plate having a plate depth of 2 μm was wound around a rubber roller to form a plate cylinder roller. After dampening water was applied to the plate cylinder roller with a dampening roller, a rosin-modified phenol resin was used as a main component. Is applied. After the ink had a predetermined pattern due to the interaction between the plate, water and the surface energy of the ink, the roller surface was irradiated with far-infrared rays to cure the ink.

Next, the plate cylinder roller was rolled on a glass substrate, and the cured ink was transferred to the glass substrate via the adhesive layer. The glass substrate was exposed to a plasma atmosphere for 10 minutes, whereby the cured ink portion remained without being affected by oxygen plasma due to the benzene ring derived from the phenol component, and the pressure-sensitive adhesive layer portion of the acrylic resin was exposed to oxygen plasma. , And as a result, only the part of the pressure-sensitive adhesive layer not covered with the cured ink was removed.

Through the above steps, a fine pattern consisting of objects having a line width of 30 μm and a film thickness (ink layer 2 μm + adhesive layer 1 μm) was accurately reproduced on a glass substrate.

〔The invention's effect〕

As described above, according to the printing method of the present invention, an intaglio plate or a lithographic plate is used. Then, after curing the curable ink patterned in the concave portion of the plate or the pattern plate portion in the concave portion or on the plate, and then transferring the cured ink to the printing medium, in the conventional printing technology Although prints with a minimum line width of only 100 to 200 μm could be reproduced, extremely fine line drawing less than 100 μm with a predetermined film thickness can be easily performed. Moreover, since the patterned curable ink is cured on the plate and is transferred to the printing medium at a stage where the ink is completely non-flowable, there is no possibility that the image shape will be distorted at the time of transfer or after transfer. The fine pattern is clearly printed and reproduced while maintaining the shape faithful to the shape patterned above. Further, since the method of the present invention employs the above-described printing means, it is possible to efficiently and inexpensively form a fine image which has conventionally had to rely on an expensive and inefficient photoresist. It became. Further, according to the present invention, by performing printing through an adhesive or tacky layer, the cured ink can be stably and easily transferred to a rigid printing medium.

Therefore, the printing method of the present invention can be widely applied to the use of fine pattern formation, and can provide, for example, glass photomasks, fine printed circuit boards, and other products requiring fine pattern formation with high precision at low cost, and have a profit. Is big.

[Brief description of the drawings]

1 (A) to 1 (F) are cross-sectional explanatory views showing one embodiment of each printing step of the printing method of the present invention, and FIGS. 2 to 5 show examples of printing steps of different aspects in the printing method of the present invention. 1 is a printing plate (intaglio plate), 2 is a concave portion, 3 is a curable ink, 3b is a cured ink, 4 is a doctor, 5 is a curing treatment by heat or radiation, and 6 is a printing target. Body, 7 ... adhesive or sticky layer

Claims (5)

(57) [Claims] 1. A method in which a curable ink is applied to a printing intaglio having a fine pattern concave portion to be a printing image portion, and ink other than the concave portion is removed by a doctor to fill only the concave portion with the ink. Alternatively, a hardened ink is applied to a printing lithographic plate obtained by making a fine pattern plate portion to be a printing image portion, and the ink is applied only to the pattern plate portion to perform patterning. A method for printing a fine pattern, comprising transferring the ink to a printing medium after curing the ink with heat or radiation. 2. The printing method according to claim 1, wherein an adhesive or tacky layer is provided on the printing medium in advance, and the cured ink is transferred to the printing medium via the layer. 3. An adhesive or tacky layer is provided on the plate surface after patterning the curable ink on the intaglio or lithographic plate, or after curing the patterned ink,
2. The printing method according to claim 1, wherein the cured ink is transferred to the printing medium via the layer. 4. The printing medium is made of metal, ceramic, glass or plastic and has rigidity.
The printing method described. 5. The printing method according to claim 2, wherein, after transferring the cured ink, an adhesive or tacky layer in a portion of the printing medium where the cured ink layer is not present is removed.