JPS59109050A - Formation of resist - Google Patents

Abstract

PURPOSE:To form easily a resist of high accuracy by forming a desired pattern on a metallic plate using a specified coating agent, coating the whole surface of the metallic plate including the pattern with an ultraviolet-curing coating agent, carrying out irradiation, and washing out the uncured parts. CONSTITUTION:A pattern 3 is formed on a metallic plate 1 on a substrate 2 using a coating agent (A) soluble in a solvent and contg. a substance for inhibiting the curing reaction of an ultraviolet-curing coating agent (B). The coating agent A includes a resin composition prepd. by blending the acrylate of bisphenol type epoxy resin with 4,4'-bisdiethylaminobenzophenone (a basic substance which doubles as a photopolymn. promotor). A layer 4 of the coating agent B such as epoxy resin blended with a photopolymn. initiator which releases Lewis acid under radiation is then laminated. The layer 4 is irradiated with ultraviolet rays to cure the layer 4 except the parts 5 on the pattern 3, and the parts 5 are removed by dissolution in a solvent to form a resist.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a resist related to an etching resist"! or a ruining resist.

In recent years, as the electronics industry has flourished, the demand for printed wiring boards has increased rapidly. Traditionally, the manufacturing method for these printed circuit boards was to use silk screen printing on the surface of copper foil laminated to a plastic sheet. Methods such as forming a circuit pattern or a method called a dry film method have been adopted. However, all of these methods have the disadvantage that the manufacturing speed is slow or the process is time-consuming.

As a result of extensive research, the present inventors have invented a new method for forming etching resists or solder resists that can solve these drawbacks.

Currently, there are two different types of compositions of radiation-curable coatings or inks, such as ultraviolet rays and electrons. One is a type in which a crosslinking vehicle containing an ethylenically unsaturated bond is combined with a photopolymerization initiator, and cured by radical polymerization.The other is a type in which an epoxy compound and a professional Lewis acid are combined and exposed to ultraviolet rays. It is a type that undergoes cationic polymerization by irradiation.In the former radical polymerization type radiation-curable composition, it is widely practiced to use an amine compound as an accelerator in addition to a photopolymerization initiator. When a cationically polymerized radiation-curable paint was coated on a radiation-curable ink using a compound as an accelerator and irradiated with ultraviolet rays, a phenomenon was observed in which the areas where the two overlapped were not cured.This was due to the radiation curing described earlier. This is thought to be due to the fact that the amine in the mold ink forms a salt with the Lewis acid that is the curing catalyst for the subsequent paint, making it difficult for cationic polymerization to occur.

The present inventors have found that etching resist material can be used to form solder resist patterns by actively utilizing this curing inhibition, and have arrived at the present invention. That is, a metal plate is coated in a desired pattern with a coating agent (A) that contains a compound that inhibits the curing of the radiation-curable coating agent (B) and that can be dissolved or swelled by a solvent. This is a resist forming method in which the entire surface including the pattern is coated with a radiation-curable coating material (B), and then radiation is irradiated and uncured or semi-cured portions are washed out with a solvent. Furthermore, it is a resist forming method in which the coating agent CA) contains a basic compound and the radiation-curable coating agent (I3) is a composition that releases a Lewis acid when irradiated with radiation.
A) contains an acidic compound, and a radiation-curable coating (I3)
This is a resist forming method that contains a basic compound as a polymerization accelerator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the resist pattern forming method according to the present invention will be described with reference to the drawings. The drawings are cross-sectional views showing an overview of the present invention. First, as shown in Fig. 1, a line drawing or pattern 3 (hereinafter referred to as pattern). Note that 2 in the drawings indicates a substrate. Of course, a metal plate (including foil) without a substrate may also be used.

Next, as shown in FIG. let At this time, the radiation-curable coating layer 5 on the pattern 3 in FIG. 2 is poorly cured due to the effect of the basic compound in the pattern 3 (C). The uncured or semi-cured portion 5 and the pattern 3 below, which has poor solvent resistance, can be easily eluted;
As shown in the figure, the exposed metal parts can be corroded by the corrosive liquid.

In addition, the object can also be achieved by using a composition containing an acidic compound as the coating agent GA) and a composition containing a curing accelerator such as an amine compound as the radiation-curable coating agent (I3).

The coating material (A) according to the present invention is a coating material containing a thermoplastic resin, a radiation-curable resin, etc., and contains a compound that inhibits curing of the radiation-curable coating material.
The latter condition requires that the resin be easily eluted by the solvent during development, so a non-reactive or non-curing resin must be used. It is an organic or water-based ink or paint made using a varnish dissolved or dispersed in a solvent. When printing or coating,
The coating material (A) may be dissolved by the components of the skewer) or
Problems such as the pattern being distorted may occur due to the force when printing or applying I3). To deal with such cases, it is advisable to bring the coating material (A) to a hardened or semi-hardened state as soon as possible after applying it to the metal plate. Accordingly, this objective can be achieved by making the coating material (A) radiation-curable. However, during development,
It is necessary to have a composition that can be bathed out with a solvent. In addition, in the case of a solvent-containing type coating material (A) that uses a thermoplastic resin as a vehicle, the solvent is scattered with hot air or an infrared lamp before applying the radiation-curable coating material (B).
It is preferable to keep it in a dry state.

As the radiation-curable coating material (B) according to the present invention, a cationic (ring-opening) polymerizable composition (Detsukishi 11) was shown in the explanation using the drawings, but it is also possible to use a radical polymerizable composition. Of course, the cationic (ring-opening) polymerizable composition is not only cured by ultraviolet rays but also cured by electron beam irradiation, and is neutralized by the basic compound in the coating material. The hardened portions are similarly inhibited from curing by both ultraviolet rays and electron beam irradiation. On the other hand, radically polymerizable curable compositions are cured by electron beam irradiation, regardless of the presence or absence of photopolymerization initiators and photopolymerization accelerators, so radiation other than ultraviolet rays can be used as a radiation-curable coating (B). Can not.

The coating material (B) needs to be radiation-curable. That is, the conditions are necessary from the viewpoint of workability and solvent resistance to the solvent used for development. 5. Another feature of the resist forming method according to the present invention is that it can be performed by printing without using a pattern mask like the dry film method. Silk screen printing has been put to practical use as a pattern forming method by printing, but it is difficult to form extremely fine lines due to the slow printing speed and lack of precision. On the other hand, various attempts have been made to directly form a resist using offset printing, but the film is only 3 μm thick at most, and not only does it not have the same resistance as etching or solder resist, but it also does not have the same resistance as a etch or solder resist. There are problems such as pinholes remaining and defects in the pattern.However, according to the method of the present invention, precise lines can be obtained by offset printing, and even if there is some film formed by the coating material (A), Even if discontinuities (pinholes, etc.) occur rarely, they have the advantage of being less of a problem because of the radiation-curable coating (I3).

The use of the resist according to the present invention is not limited to simply printed wiring, but can also be used for processing, ching, or solder resist for obtaining a pattern on a contact plate. In this case, metal plates such as aluminum and stainless steel are also used in addition to copper plates.

Note that the metal plate also includes gold rhinoceros foil.

The composition of the coating material (B) is selected from the following materials in consideration of the type of radiation-curable coating material (B).

When the coating material (A) is an ultraviolet curable type, the film-forming components include bisphenol-type epoxy resin acrylate, novolak epoxy resin acrylate, polyester acrylate, urethane-modified polyester acrylate,
A relatively high viscosity vehicle represented by acrylic acid-modified alkyl, do, etc. and a relatively low viscosity acrylic ester as required.
For example, a combination of trimethylolpropane triacrylate, diethylene glycol diacrylate, dipentaerythritol hexaacrylate, etc. is used. Furthermore, a vehicle obtained by dissolving a resin which itself is not UV curable, such as an epoxy resin, a ketone resin, an amino resin, or a polydiallyl phthalate resin, with the above-mentioned low-viscosity polyacrylate can also be used as a film-forming component. As photopolymerization initiators, hapenzophenone, methyl orthobenzoylbenzoate, thiozanthone, benzoin or -t ester, 2,2-jethoxyacetophenone, 2-hydroxy-2-methylglobiophenone, dibenzosuberone, etc. can be used. Further, as the photopolymerization accelerator, trimethylamine, jetanolamine, alkyl dimethylaminobenzoate, 414'-bisdiethylaminobenzophenone, etc. can be used. 1st
If the ink is a UV-curable coating material like this, the photopolymerization accelerator is a basic substance, so there is no need to add a basic substance, but it is necessary to add a basic substance as described below. You can also do it.

Next, when the coating material (A) is of a radiation-curable type such as an electron beam, the film-forming components used in the above-mentioned ultraviolet-curable coating material can be used as they are, but a photopolymerization initiator is not necessarily required. However, it is necessary to add a basic compound to inhibit curing of the second coating material. For example, in addition to the heptamine-based photopolymerization accelerator mentioned above, ethylenediamine, p-phenylenediamine, triethanolamine, etc. can be used.

In addition, if the radiation-curable coating material (in the radiation-curable coating material) is applied onto the printed or applied coating material (A) and then heated to 50°C to 100°C, the curing-inhibiting substance will be sufficiently diffused and the curing-inhibiting substance will be inhibited. It has been experimentally confirmed that this is likely to occur. Therefore, when the film thickness of the coating material (13) is 5 μm or more, such heating is an effective means.

The formulation when the coating agent' (A) is a solvent-drying type will be described. The film-forming component is rosin-modified alkyl.

A resin selected from the group consisting of phenol-modified rosin alkyd, drying oil or semi-drying oil-modified alkyd, ketone resin, benzoguanamine resin, rosin and/or fatty acid epon ester, phenol resin, and urethane alkyd resin is used by dissolving or diluting it with a solvent. The solvent used is
Depending on the printing (or coating) method of coating material (A),
.

You need to change points and types. When using an offset printing machine, considering swelling of the rubber roll and blanket and volatilization on the machine, a hydrocarbon solvent with a boiling point in the range of 240°C to 320°C and containing aromatic hydrocarbons at a concentration of 40 parts or less is recommended. is desirable. In addition to solvents, linseed oil, soybean oil,
Oils and fats such as dehydrated castor oil and tung oil can also be used together, but in this case, a manganese dryer, a cobalt dryer, etc. may be added as necessary. As the basic compound to be used in combination, the photopolymerization accelerator mentioned above can be used, and furthermore, ethylenediamine, p-phenylenediamine, diaminodiphenylmethane, metaphenylenediamine, trimethylenediamine mono(di)ethanolamine, etc. can be used.

This objective can be achieved even if the coating agent (A) is an aqueous or glycol- or alcohol-soluble composition. Film-forming components include maleated rosin or its amine, ammonia, and alkali! Salts such as 1M, shellac, polyvinyl alcohol, carboxymethyl cellulose, water-soluble alkyds, water-soluble acrylic resins, etc. can be used. Although the above-mentioned amines can be used as basic substances, it is not necessarily necessary to add amines in coatings using an alkaline water solubilizing vehicle. In addition to water, solvents that can be used to adjust the hardness of water-based inks include ethylene glycol, diethylene glycol, glycerin, ethyl cellosol,
Examples include butyl alcohol, methyl isobutyl ketone, and the like.

For any of the above-mentioned types of coating material (A), a coloring agent such as a pigment or a dye may be mixed in to facilitate confirmation of the pattern. Furthermore, extender pigments may be used to adjust the hardness of the ink. Furthermore, various additives that are usually added to inks or paints can also be used in combination.

Note that the method for patterning the coating material (A) is as follows:
Wet offset printing, dry offset printing, rubber letterpress printing, octopus printing, flexographic printing, screen printing, etc. can be used, but wet offset printing that uses dampening water does not allow acid or basic compounds in the coating material. It is also possible that the aluminum plate material may be attacked depending on the type of plate. Therefore, in such a case, it is necessary to employ a method that does not use dampening water, such as dry offset printing.

The above-mentioned coating (A) is a radiation-curable coating that is printed or painted on the pattern.
Although cationic polymerization type or radical polymerization type coating materials can be used, since the radical polymerization type is also mentioned in the explanation for coating material (A), the explanation will be omitted, and the cationic polymerization type composition of the epoxy resin will be explained. This cation (ring open)
The epoxy resin used for the M trapezoidal coating can be selected from bisphenol type epoxy resins, novola type epoxy resins, alicyclic epoxy resins, and alicyclic epoxy resins. Diazonium salts such as BF, F e CA s, PF, etc. can be used as photopolymerization initiators capable of releasing silicate acids by radiation. For example, p-nitrobenzenediazonium hexafluorophosphate-1-,2,5-dichlorobenzenediazonium hexafluorophosphate, 214
-dichlorobenzenediazonium tetrafluoroborate, p-nitrobenzenediazonium tetrachloroferrate%2,47 chlorobenzenediazonium hexachlorostanate, and the like. If a coloring agent or the like is added to the coating material (of this world) in the same way as the coating material (A), the pattern after development can be easily confirmed.

Next, when the coating material (B) is a radiation-curable composition containing a basic compound as a photopolymerization accelerator, examples of the coating material (A) used in combination with this composition include a coating material having the following formulation. In this case, when the coating material (A) is of the radiation-curing type, the radiation-curing type and cationic ring-opening polymer composition described above can be used as is.

In addition, when the coating material (A) is a solvent-volatile dry composition,
By using an acidic substance in place of the basic substance used in the above-mentioned solvent-based formulation, curing inhibition of the radiation-curable coating material (B) can be caused. Examples of acidic substances that can be used for this purpose include sulfones such as p-toluenesulfonic acid, boron trifluoride and its etherates, and phosphorus pentafluoride. Acidic and basic substances are usually 0.
By using a weight ratio of 5 to 10, preferably 1 to 5, curing inhibition can be effectively caused.

The application of the present invention is to form a coating for a ruster resist, but this is done by immersing the etching substrate in a solder bath instead of immersing it in a corrosive solution as described above. , impermanence is a necessary condition.

For this purpose, it is important to have good curability and heat resistance for radiation-curable coatings, and good adhesion to copper.

It was found that improvements could be made by blending talc into the coating material on a 15-weight plate and reducing the amount of low molecular weight oligomers to form a hard film.

Example 1 (A) (I-1) was prepared using the following recipe.

(I-1) Phthalocyanine green 2 Heavy duty talc
5 White Glossy Man(”' 30 Lipoxy 5
P-1509” 37;9 tr-benzophenone 3 □Ethyl ketone
Q, 1 #S Power Roll 506 (4) 3 DPHA (5) ' 19 (Total 100
#) (1) Light calcium carbonate (Shiraishi Kogyo) (2) Bisphenol type epoxy acrylate (Showa Kobunshi Dan) (3) 44'-bis(diethylamino)benzophenone (4) Amyl N-dimethylaminobenzoate (Pan Dijk) Coating agent (I-2) of (5) Dipentaerythritol hexaacrylate (Nippon Kareimei Co., Ltd.) (13) was prepared using the following formulation.

(knee 2) Mitsubishi Carbon MA-112% by weight Talc 10, /.

White Glossy Man 30 1AI)-8
107 (6) 55 #catalyst p p -33” 3 tt (total 100,,) (6) Epoxy resin (manufactured by Asahi Denka) (7) Acid catalyst (manufactured by Asahi Denka) Using coating material (I-1,) Line drawings with widths of 50 microns, 100 microns, and 500 microns were printed on a copper foil laminated board for printed wiring (copper thickness 18 microns) using an offset printing machine, and immediately after that, a 100 m line drawing was printed using a high-pressure mercury lamp (40 W/crn input). Then, coating material (I-2) was printed on the entire surface with a thickness of 6 microns using an offset printing machine, and a high-pressure mercury lamp (
80w/cm input) Passing under 3 lights at 100m/min,
It was irradiated and cured. The phenomenon occurred in about 1 minute by immersing the thus-produced printed matter in ethanol and shaking it. After air drying, copper was corroded with a saturated aqueous solution of ferric chloride.5
The 0 micron, 100 micron, and 500 micron lines were clearly corroded.

Example 2 Coating agents (A) (It-1) and (I3) were prepared in each of the following formulations.
) A coating material (II-2) was prepared. Coating agent (II-1)
A line drawing was printed using the same method as in Example 1, and irradiated with ultraviolet rays. Next, the paint (It-2) was applied to the entire surface of the printed matter using a roll coater, cured with ultraviolet light under the same conditions as in Example 1, and developed with a mixture of inpropyl alcohol and methyl cellosolve (1:1). A substrate for etching was obtained. When etched in the same manner as in Example 1, sharp corrosion (
II-x) Mitsubishi Carbon ≠ 55 3 Weight% Alumina White 5 White Glossy 28 Fues A (Li 35.9 ttA
, TMPT(2)20 CTX("l 1 〃MO
BB+4n
4 Diethanolamine 3 Hydroquinone 0.1 □ (total 1
00.0 〃) (1) Varnish A: A varnish prepared by dissolving 35 parts of DiSoda and BuK (diallyl phthalate resin) in 65 parts of D PHA.

(21) ) Limethylolpropane triacrylate (3) 2-chlorothiozanthone (4) Methyl-〇-benzoylbenzoic acid (fl-2) Phthalocyanine Green 1.5 it k
113-6100(5) 95.5
Example 3 A body coating (I[1-1) was prepared according to the following formulation,
Printing was performed on the same substrate as in Example [1] in the same manner as in Example 1, and the solvent was evaporated with hot air at 180° C. to semi-dry it.

(IIT-1') Phthalocyanine green 2NM% white glossy
25 Orhen 2 Worth B ('') a No. 74 Ruben, (31,25 Linseed oil 5 Ethylenediamine 4 (Total '100.0〃) (1) Surface treated bentonite (Shiraishi Kogyo) (2)
'7 Varnish B: A fest made by dissolving 46 parts of Tamanol 352 (rosin-modified phenolic resin: manufactured by Arayo Kagaku) in 17 parts of linseed oil and 37 parts of No. 4 solvent.

(3) Petroleum solvent (manufactured by Nippon Oil) Next, using the coating material (II-2) of (B) obtained in Example 2, it was coated in the same manner as in Example 2 and irradiated with ultraviolet rays. Development was carried out as in Example 1 using a 1:1 mixture of inglobil alcohol toxylol as a developer, and then etching was carried out in the same manner as in Example 1. As in Example 1, good results were obtained.

Example 4 Coating material (IV-1) (5) was prepared according to the following formulation.

(IV-1) Titanium White R-670" 5 Weight C (2) 74 Ethyl Cellosolve 15 28 Thiammonia Water 6 (Total 100 Weight) (1) Made by Ishihara Sangyo (2) '7 Varnish C: 22% maleated rosin 40
After dissolving 1 part in 57 parts of ethylene glycol, 3 parts of monoethanolamine was added to form a fest.

71/ Using a xo printing machine, print a floral pattern on a mirror-finished aluminum plate of 1 thick/thickness, blow hot air at 150°C to volatilize some of the water and ethylene glycol, and then apply the formula (■ The coating material (13) prepared in -2) was applied by the method of Example 2. Development was carried out in the same manner as in Example 1 using isopropyl alcohol as a developer. Cover the back side with PET film (tack paper) and add 2 q of caustic soda.
(b) The exposed aluminum part was corroded 1~ with an aqueous solution, and a flower stalk was attached.

(IV-2) B-6136J" 98 parts by weight catalyst A L') 2 ・(total
(100 parts by weight) (5) Epoxy resin (electrified) (6) P-nitrobenzenediazonium-hexafluorophosphate Example 5 Using (A) coating material (V, -1) prepared with the following formulation,
50 micron dry offset printing using a resin letterpress on a copper laminated board for printed circuit boards (copper thickness 18 micron)
067〃 1) p-33,3/L (total 100#) Print 100 micron and 500 micron line drawings and UV
Without irradiation, the coating material (13) (V
-2) was printed on the entire surface, and then heated by passing under five 5 kW/m far-infrared heaters at 10 on at 60 m/min, and then cured with five high-pressure mercury lamps (80 W/cm input). Developed with a 1:1 mixture of toluene and isopropyl alcohol,
We obtained a printed circuit board.

(V-2) Phthalocyanine Green 2 Xt% Talc 5 Alumina White 23 2-vitane 788”,
42 uABPE-14”
20 Benzophenone
3 Ethyl ketone 2
〃S Power Roll 506 3 /I (
Total 10C) #) (1) Urethane-modified acrylic resin (Thiocol) (2) Bisphenol A dioxy diethylene glycol ether diacrylate (Shin Nakamura Chemical) Example 6 Made with the following formulation; e(A) coating material ( ■ ~ 1) was used for offset printing on a copper foil laminated board for printed circuit boards (copper thickness 18 microns), and after semi-drying with hot air at 180°C, coating material (M-2) of (B) was applied over it. Offset printing was performed on the entire surface to a thickness of 5 microns, and the film was cured by passing under 5 high-pressure mercury lamps (80 W/CRN input) at 60 m/min. Cyclohexane and Quijirol 3:1
After developing with a mixed solvent, it was placed in a solder bath at 26.0℃
When immersed for 0 seconds, no flaking or peeling of the film was observed.

(■-1) Phthalocyanine green 2 weight t% white gloss 25 〃-olben
2 Varnish Bfl)
37 rr No. 4 Solvent
25 □Linseed oil
5 p-toluenesulfonic acid 4 (total
100) (1) Same as the festival used in ll-1 of Example 2.

(■-2) Phthalonanine Blue 2 M ft% Talc 15 White glossy
20 Lipoxy 5P=1509
37 Benzophenone
3 〃Ethyl Ketone 2 〃Esu Power Roll 506 3 /.

A'BPE-4' 1!5 #N-vinylpyrrolidone 2 (total 100) Example 7 In the process of Example 1, ultraviolet curing was used as a method of curing the coating material (1-2) of (B). Instead, the same result was obtained by using the same method as in Example 1, except that 5 Mrad electron beam irradiation was carried out under a nitrogen stream for curing.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views showing embodiments of the present invention. Symbols in the figure: 1 - Metal plate, 3 - Pattern, 4 - Radiation curable coating layer, 5 - Partially inhibited curing of radiation curable coating 4 layers Patent applicant: Toyo Ink Mfg. Co., Ltd.

Claims (1)

[Scope of Claims] 1. A metal plate is coated in a desired pattern with a radiation-curable coating agent (A) which contains a compound that inhibits curing and which can be dissolved or swelled by a solvent. ,death,
Next, the entire surface including the pattern is coated with a radiation-curable coating material (B), and then radiation is irradiated, and uncured or semi-cured portions are further washed out with a solvent. 2. The resist forming method according to claim 1, wherein the coating material (A) contains a basic compound, and the radiation-curable coating material (B) is a composition that releases a Lewis acid upon irradiation with radiation. 3. The resist forming method according to claim 2, wherein the coating agent (A) is a radiation-curable composition. 4. The resist forming method according to claim 2 or 3, wherein the coating agent (A) is a water-soluble resin composition containing a basic compound. 5. The resist forming method according to claim 1, wherein the coating material (A) contains an acidic compound, and the radiation-curable coating material (B) contains a basic compound as a polymerization accelerator. 6. The resist forming method according to any one of claims 1 to 5, wherein the metal plate is a copper plate for printed circuit board wiring.