JPH07331149A - Copper through-hole filling ink for printed wiring board manufacturing and method of using the same - Google Patents

Abstract

(57) [Summary] [Structure] (A) The following general formula [I] or [II] [Chemical 2] {In the formula, R ₁ is hydrogen or a methyl group, R ₂ is hydrogen or an alkyl group having 1 to 4 carbon atoms, Y is an alkylene group having 1 to 4 carbon atoms, or-(C _n H _2n O) _P --CH _2- (In the formula, n is 2 to
An integer of 6 and p is an integer of 1 to 19. ) Represents a group represented by. } A copper through-hole printed wiring containing 1 to 90% by weight of a monoester compound represented by the formula (B), 0.01 to 20% by weight of a thermal polymerization catalyst (B) and 0.01 to 20% by weight of a (C) photopolymerization catalyst. It is a hole-filling ink for manufacturing a substrate, and when used, it is cured by pre-curing with ultraviolet rays and subsequent thermal polymerization by heat treatment. [Effect] There is no polymerization failure due to oxygen damage and excellent polymerizability, there is no volume shrinkage due to evaporation of volatile components during heating, through hole protection and the edge covering function of through holes are excellent, and it is easy to use an alkaline aqueous solution. Can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hole filling ink used in a copper through hole printed wiring board manufacturing process and a method of using the ink.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing the above-mentioned double-sided printed wiring board, Japanese Patent Application Laid-Open No. 04-62887 and Japanese Patent Application Laid-Open No.
Generally, the following steps are adopted, as disclosed in, for example, 5-102290. That is, first, a through hole is formed at a desired position of the double-sided copper-clad laminate, a conductive plating layer is formed in the hole by a through hole plating method, and a through hole for electrically connecting the front and back conductor patterns is formed. To do. Next, a solvent dry type hole filling ink is filled in the through hole and the hole filling ink is cured by evaporation of the solvent, or an ultraviolet curing type hole filling ink is filled in the through hole and the hole is formed. UV cure the fill ink. Then, a desired pattern is formed on the front and back surfaces of the laminate with an acid-resistant ink, and after curing the acid-resistant ink, the exposed copper portion is cupric chloride.
The double-sided printed wiring board is prepared by etching away with an acid etching solution such as ferric chloride and further removing the hole filling ink and the acid resistant ink with an alkaline aqueous solution.

Various types of solvent-drying or UV-curing hole-filling inks used in the above-mentioned processing steps have been put to practical use.

However, the solvent-drying type hole-filling ink generally requires a long time for curing and has a large volume contraction of 20 to 50% due to the evaporation of the solvent contained therein. Is insufficiently protected, and that portion is easily etched during etching, and the performance of the printed wiring board is likely to deteriorate.

On the other hand, the ultraviolet curable hole-filling ink has a small volume shrinkage due to curing, but requires a sufficient amount of exposure to complete the ultraviolet curing reaction in the deep part of the through-hole, and thus long exposure is inevitable. In addition, when removing the cured product from the through hole, there are problems such as peeling with an alkaline aqueous solution, poor removability, and a part of the cured product remaining attached to the inner wall of the through hole, which causes troubles during component mounting. It is easy to occur.

To solve the above-mentioned problems of peeling and removability,
It is possible to mix fillers such as extender pigments and color pigments, which are inert solid powders, into the UV-curable hole-filling ink. The mold filling ink becomes more difficult to cure due to the addition of the above-mentioned filler. In particular, when a coloring pigment such as titanium oxide is used, it does not substantially have the function and effect as an ultraviolet curable hole-filling ink.
It cannot be used as a filling ink. Therefore, the type of inert solid powder that can be actually mixed is talc,
It is an extender pigment that has UV transparency, such as fine powder silica, and its blending amount is limited, so it is not easy to remove unnecessary hardened parts by buffing after the hole filling ink curing process, and alkali peeling is possible. It is also difficult to improve the sex.

For the above reasons, both solvent-drying type and ultraviolet curing type hole-filling inks have the performance required as hole-filling inks to cope with the recent fine patterning of printed circuit boards. It was in a state where improvement could not be achieved sufficiently. The inventor of the present invention has filed a patent application No.
No. 151,359 proposes a hole filling ink using a thermal polymerization reaction. This heat-polymerizable hole-filling ink is characterized in that it can be cured in a short time, its volume shrinkage due to evaporation of a solvent or the like is small, and that it has excellent through-hole protection and can be easily removed by an alkaline aqueous solution. However, only by curing by thermal polymerization, due to poor polymerization due to oxygen damage, volume reduction due to volatilization of ink components before completion of thermal polymerization in the thermal polymerization process, and reduction in through hole edge covering function, etc. The present situation is that the protective effect of is not perfect.

[0008]

The object of the present invention is not to cause polymerization failure due to oxygen damage and to have excellent polymerizability, to prevent volume contraction due to evaporation of volatile components during heating, to have excellent through-hole protection, and to prevent alkali. It is an object of the present invention to provide a hole-filling ink for producing a copper through-hole printed wiring board that can be easily removed with an aqueous solution, and a method of using the ink. Another object of the present invention is to make it possible to increase the compounding amount of the inert solid powder in the hole filling ink, and to easily remove the unnecessary hardened portion by buffing or the like after the step of hardening the hole filling ink. It is to provide a filling ink that can be filled.
Still another object of the present invention is to provide a hole-filling ink capable of blending a coloring pigment such as titanium oxide among inert solid powders, and particularly improving the visibility at the time of hole-filling state inspection of a circuit board. To do.

[0009]

The hole filling ink for producing a copper through-hole printed wiring board according to the present invention comprises (A) the following general formula [I] or [II]:

[0010]

[Chemical 3]

[0011]

[Chemical 4]

{Wherein R ₁ is hydrogen or a methyl group, R ₂ is hydrogen or an alkyl group having 1 to 4 carbon atoms, and Y is 1 to 4 carbon atoms.
Alkylene group or a _{- (C n H 2n O)} P -CH 2 - ( wherein, n an integer of 2 to 6, p is an 1-19 integer.)
Represents a group represented by. } The monoester compound represented by 1 to 90% by weight, (B) the heat polymerization catalyst 0.01 to 20% by weight, and (C) the photopolymerization catalyst 0.01 to 20% by weight.

The monoester compound represented by the general formula [I] or [II] used as the component (A) of the hole filling ink according to the present invention has, for example, a polyvalent carboxylic acid and a vinyl unsaturated group. Examples include monoesterified products of alcohol.

As the polycarboxylic acid, phthalic acid,
Tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid,
3-propyltetrahydrophthalic acid, 4-propyltetrahydrophthalic acid, 3-butyltetrahydrophthalic acid,
4-butyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid,
4-ethylhexahydrophthalic acid, 3-propylhexahydrophthalic acid, 4-propylhexahydrophthalic acid,
Examples thereof include 3-butylhexahydrophthalic acid and 4-butylhexahydrophthalic acid. Especially preferred among these are tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid and 4-methylhexahydrophthalic acid.

Examples of the alcohol having a vinyl unsaturated group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 2
-Exemplify vinyl monomers such as hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate and polycaprolactone mono (meth) acrylate. You can

The monoester compound of the above component (A) is
Although it can be synthesized by various conventional synthesis methods, it can be easily obtained particularly by a ring-opening addition reaction of an anhydride of the polyvalent carboxylic acid with a vinyl monomer. The content of the component (A) is 1 to 90% by weight based on the whole hole-filling ink. If it is less than 1% by weight, the removability of the hole-filling ink with an aqueous alkaline solution is lowered, and if it exceeds 90% by weight, the viscosity is increased. Due to the rise, it becomes difficult to fill the through hole with the filling ink. A particularly preferable range of the compounding amount of the component (A) is 5 to 50% by weight.

As the thermal polymerization catalyst which is the component (B) of the hole-filling ink according to the present invention, a catalyst capable of initiating thermal radical polymerization is used, but it has good storage stability after blending. Required.

Examples of the above-mentioned thermal polymerization catalyst include hydroperoxides such as diisopropylbenzene hydroperoxide, cumene hydroperoxide, and t-
Butyl hydroperoxide, dicumyl peroxide of dialkyl peroxides, 2,5-dimethyl-2,5-di- (t-butylperoxy) -hexane, 1,3-bis- (t-butylperoxy) Isopropyl) -benzene, t-butyl cumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,
5-di- (t-butylperoxy) -hexyne-3, and diacyl peroxides such as isobutyryl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, benzoyl peroxide,
Acetyl peroxide, and ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, acetylacetone peroxide, and alkyl peresters such as t-butyl peroxybibalate, t
-Butylperoxy-2-ethylhexanoate, t-
Butyl peroxy-3,5,5-trimethyl hexaate, t-butyl peroxy acetate, t-butyl peroxy benzoate, and peroxy dicarbonates diisopropyl peroxy dicarbonate, di-2-
Ethylhexyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, and azo compounds such as azobisisobutyronitrile, azobiscyanovaleronitrile, 1,1′-azobis (cyclohexene-1) -Carbonitrile), 2,2'-azobis {2-methyl-N-
(2-hydroxyethyl) -propionamide} and the like can be mentioned, and these can be used alone or in an arbitrary ratio.

The blending amount of the component (B) is 0.01 to 20% by weight based on the whole filling ink, and this is 0.01%.
If it is less than 20% by weight, the thermal radical polymerization property is remarkably lowered, and if it exceeds 20% by weight, the etching resistance is lowered.

As the photopolymerization initiator which is the component (C) of the hole-filling ink according to the present invention, a usual compound which generates a radical or a Lewis acid by a photochemical reaction after irradiation with visible light, near-sightedness or ultraviolet rays is used. However, those having high spectral sensitivity in the ultraviolet region are preferable in consideration of workability and the like.

Benzophenones, vicinal ketones, such as diacetyl, benzyl, α-pyridyl, and acyloins, are compounds that induce radical polymerization reactions.
For example pivaloin, α-pyridoin, and benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, and acetophenones such as 4-phenoxydichloroacetophenone, 4-t-butyl. -Dichloroacetophenone, diethoxyacetophenone, and thioxanthones, such as 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone,
Thioxanthone derivatives such as 2,4-dipropylthioxanthone, and anthraquinones such as ethylanthraquinone, benzanthraquinone, diaminoanthraquinone, and camphorquinone, 4,4′-in addition to these.
Bis (dimethylamino) benzophenone, dibenzosuberone, 4,4'-diethylisophthalophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, acylphosphine oxide, 2,4,6-Trimethylbenzoyldiphenylphosphine oxide can be mentioned. Among these, benzophenones, thioxanthone and its derivatives, and anthraquinones are particularly preferable. The above compound is
They can be used alone or as a mixture of two or more kinds.

Further, as the photopolymerization initiator for inducing the cationic polymerization reaction, aryldiazonium, diarylhalonium, triphenylphosphonium, dialkyl-
PF such as 4-hydroxysulfonium, dialkyl-4-hydroxydiphenylsulfonium, allene-iron complex
₆ ⁻ , As F ₆ ⁻ , BF ₄ ⁻ , Sb F ₆ ⁻ salt and the like can be mentioned.

Further, an amine photoinitiator aid, which itself is not activated by irradiation of ultraviolet rays but accelerates the photopolymerization initiating reaction when used together with a photoinitiator, can also be used. Aliphatic and aromatic amines are mainly used as such photoinitiator aids, for example, triethylenetetramine, triethanolamine, methyldiethanolamine, triisopropanolamine, n-butylamine,
N-methyldiethanolamine, diethylaminoethylmethacrylate, Michler's ketone, 4,4'-diethylaminophenone, ethyl 4-dimethylaminobenzoate, (n-butoxy) ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, etc. Can be mentioned. Among these, especially Michler's ketone,
4,4′-diethylaminophenone, ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoic acid (n-
Aromatic amines such as butoxy) ethyl and isoamyl 4-dimethylaminobenzoate are preferred.

The content of the component (C) is 0.01 to 20% by weight based on the whole filling ink, which is 0.01%.
If it is less than 20% by weight, the surface curability of the hole-filling ink during exposure is significantly lowered, and if it exceeds 20% by weight, the etching resistance is lowered.

Examples of the component (D) of the hole filling ink according to the present invention include talc, silica, aluminum hydroxide, titanium oxide, barium sulfate, as extender pigments and coloring pigments.
Inorganic solid particles such as kaolin, calcium carbonate, phthalocyanine and the like, organic polymer particles such as polyethylene, nylon and polyester, and a thixotropic agent such as Aerosil can be mentioned.

By mixing these, the general purpose as a filler, such as improving the filling property and filling state when the hole filling ink is filled in the through hole, can be achieved. The mechanical polishing property of the cured product after curing the hole filling ink is improved, and the alkali releasability of the cured product is improved, so that the cured product is removed when the cured product of the hole filling ink is removed from the through hole in the final step. It is completely removed without remaining on the inner wall of the through hole, and problems such as mounting of parts are prevented.

As the component (D), if necessary, it is possible to blend an inert solid powder which is substantially opaque to ultraviolet rays.

In the conventional UV-curable hole-filling ink, when an inert solid powder is blended, the curability in the deep part of the through-hole decreases, so in order to suppress this decrease in curability to an allowable range, it is actually an extender pigment. In addition, there was no choice but to mix it in a small amount. In particular, when a coloring pigment such as titanium oxide is used, the hole-filling ink filled in the through-hole cures only in the superficial layer, and has substantially no action or effect as a UV-curable hole-filling ink. Since it does not exist, it cannot be used as a filling ink.

In the present invention, being substantially opaque to ultraviolet rays means that the coating film before or after curing of the formed hole-filling ink has extremely low ultraviolet transmittance. Examples of such an inert solid powder which is substantially opaque to ultraviolet rays include coloring pigments such as titanium oxide, zinc oxide, zinc sulfide, antimony oxide, carbon black, graphite and chrome yellow. When these color pigments are blended, the visibility in the visual inspection of the filling state of the through holes can be improved. For this purpose, titanium oxide, which is substantially opaque to ultraviolet rays, is preferably used as a white pigment having particularly excellent visibility among the above color pigments.

The component (D) is blended in the hole-filling ink of the present invention as needed, and the blending amount is not particularly limited, but the preferred range is 5 with respect to the whole hole-filling ink.
The amount is up to 90% by weight. If it is less than 5% by weight, the mechanical polishing property of the cured product is not improved, and if it exceeds 90% by weight, the viscosity increases and it becomes difficult to fill the through hole with the filling ink.

The resin used as the component (E) of the hole filling ink according to the present invention is a phenol resin, a cresol resin or a rosin resin having an acid value of 50 to 500. These resins may be used alone or in combination of two or more. Can be used together. Among the above resins, the novolac type is preferable for the phenol resin and the cresol resin. Resol type resins and other alkylphenol resins are not preferable as the present component because they are inferior in removability with an alkaline aqueous solution, but they can be used supplementarily.

Examples of the rosin-based resin include natural resin gum rosin, wood rosin, chemically modified hydrogenated rosin, polymerized rosin, rosin-modified maleic acid resin, rosin-modified phenolic resin and the like. The softening point of these rosin-based resins is preferably 60 ° C. or higher. If the softening point is lower than 60 ° C., the hardened hole-filling ink is softened at the time of etching, and the through-hole protecting action is likely to be lowered. Softening point is especially 80
Optimum protective effect is obtained when the temperature is above ℃. Further, the acid value must be 50 to 500. If it is less than 50, the removability with an alkaline aqueous solution is lowered, and if it exceeds 500, the acid resistance to the etching solution is lowered, and the through-hole protecting action at the time of etching is reduced. descend. From this point, the particularly preferable range of the acid value is 100 to 400.

The component (E) is added to the hole-filling ink of the present invention as needed, and by adding this, the removability of the hole-filling ink with an alkaline aqueous solution can be improved. The blending amount is not particularly limited, but it is preferably 70% by weight or less with respect to the entire hole-filling ink, and when it exceeds 70% by weight, the viscosity of the hole-filling ink increases because of increase in viscosity. Filling becomes difficult.

If desired, the hole-filling ink according to the present invention may further contain a vinyl monomer other than the monoester compound of the component (A). Examples of such unsaturated compounds include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cellosolve (meth) acrylate, methyl cellosolve (meth) acrylate, butyl cellosolve (meth).
Acrylate, carbitol (meth) acrylate, methyl carbitol (meth) acrylate, butyl carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, dicyclopentadienyloxyethyl ( (Meth) acrylate, vinyl acetate, N-vinylpyrrolidone (meth) acrylic amide, tetrahydrofurfuryl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate, Monofunctional vinyl monomers such as polycaprolactone mono (meth) acrylate, phenylglycidyl ether (meth) acrylic acid adduct, and polyethylene glycol di (meth) acrylate ) Acrylate, polypropylene glycol di (meth) acrylate, polybutylene glycol di (meth) acrylate, bifunctional vinyl monomers such as polycaprolactone di (meth) acrylate. The blending amount of this component is preferably 50% by weight or less based on the whole filling ink.
If it is used in an amount of more than 0% by weight, the removability with an alkaline aqueous solution tends to be lowered.

In the hole-filling ink according to the present invention, various additives such as adhesion promoters such as silane coupling agents, defoaming agents, leveling agents, etc., or hydroquinone, hydroquinone monomethyl ether, pyrogallol, tertiary butyl, etc. Polymerization inhibitors such as catechol and phenothiazine,
Further, a surfactant, a polymer dispersant, or the like may be added to improve dispersion stability.

The hole-filling ink according to the present invention contains the above-mentioned respective components and additives, for example, a three-roll, ball mill,
It can be prepared by using a sand mill or a mixer alone or in combination and kneading by a known method. Further, the hole-filling ink can be pre-cured by a known exposure method, and can be thermally polymerized by a known heat-curing method.

FIGS. 1 (A) to 1 (E) are cross-sectional views of a main part showing a specific example of a method of using the hole filling ink according to the present invention.

As shown in FIG. 3A, an epoxy resin,
Insulating substrate 1 made of polyimide resin, polyester resin or the like, a copper clad laminate having copper foils on both upper and lower surfaces thereof, a metal type insulating substrate or a ceramic substrate obtained by insulating a metal such as aluminum or iron with an epoxy resin or the like. , The insulating substrate 1 made of a material used for a usual printed wiring board,
A copper plating layer 3 is formed on both surfaces and the inner wall of the through hole 2 provided therein by electroless copper plating or by combined use of electroless copper plating and electrolytic copper plating.

Next, as shown in FIG. 1B, the hole filling ink 4 according to the present invention is used to protect the inner wall of the through hole 2 from the etching solution by the dip filling method, the screen printing filling method, It is filled by a pin filling method, a roll filling method, or the like. Subsequently, this substrate is exposed on both sides using a high-pressure mercury lamp, a metal halide lamp, or the like with a light amount of 50 to 2000 mj per side, and the surface is preferably 5 μm.
Preliminary curing is performed to the above thickness, and heat polymerization is further performed at 80 to 150 ° C. for 5 minutes to 2 hours.

At this time, the filling ink 4 in the through hole 2 has a filling rate of about 90 to 100% of the volume of the through hole 2 without exceeding the thickness of the printed wiring board. Therefore, the hole-filling ink 4 on the surface of the copper plating layer 3 is easily removed at a low polishing pressure during mechanical polishing in a later step,
The filling of the hole filling ink 4 in the copper plating layer 3 and the through hole edge portion 2a does not occur, and the filling rate of the hole filling ink 4 can be maintained at 90 to 100% even by the mechanical polishing.

Next, as shown in FIG. 3C, an etching resist layer 5 is formed in a desired pattern on the surface of the copper plating layer 3 after mechanical polishing, for which, for example, an etching resist ink for screen printing is used. To be When the hole filling ink 4 according to the present invention is used, since the hole filling ink 4 in the through hole 2 is excellent in flattening, a desired wiring pattern can be accurately and uniformly formed in the opening of the through hole 2 and its peripheral portion. It is possible to print on. The etching resist layer 5 can be formed by using a dry film resist, an electrodeposition resist, a liquid resist, or the like in addition to the screen printing etching resist ink.

Subsequently, as shown in FIG. 3D, in the etching step, the copper exposed portion is removed by etching with an etching solution. An acidic etching solution such as ferric chloride solution or cupric chloride solution is used as the etching solution.

Finally, as shown in FIG. 6E, the etching resist layer 5 and the hole filling ink 4 are dissolved and removed by an aqueous solution of an inorganic alkaline substance such as caustic soda, caustic potash and sodium metasilicate, that is, an alkaline aqueous solution,
The intended copper through-hole printed wiring board is obtained.

The various conditions, steps and the like in the above method of use are merely examples and do not limit the present invention.

[0045]

EXAMPLES The present invention will be specifically described below with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to these examples. All parts and% used below are based on weight.

[Synthesis Example 1] 154 g (1 mol) of hexahydrophthalic anhydride, 116 g (1 mol) of 2-hydroxyethyl acrylate, 0.1 g of N, N-dimethylbenzylamine and 0.1 of hydroquinone monomethyl ether.
g was reacted in the same manner as in Synthesis Example 1 to obtain a monoester compound (A-1).

[Synthesis Example 2] 168 g (1 mol) of 4-methylhexahydrophthalic anhydride, 144 g (1 mol) of 2-hydroxypropyl methacrylate, 0.1 g of N, N-dimethylbenzylamine and 0.3 g of hydroquinone were added. The monoester compound (A-
2) was obtained.

[Production of Filling Inks of Examples 1 to 6 and Comparative Examples 1 to 3] Various components are blended based on the blending composition (unit:%) of Examples and Comparative Examples shown in Table 1 below. Along with each of the three rolls, kneading was performed to prepare the hole filling inks of Examples 1 to 6 and Comparative Examples 1 to 3 according to the present invention.

Next, regarding the hole filling inks of Examples 1 to 6, the double-sided copper clad laminate having the through holes formed was dipped in the hole filling ink according to the process shown in FIG. After filling with the filling ink, the filling ink was taken out and the hole filling ink adhering to both surfaces of the laminate was scraped off with a urethane squeegee. Subsequently, this laminated plate was exposed under a condition described in Table 2 by using a high pressure mercury lamp, the hole filling ink was pre-cured from both sides, and further thermally polymerized. afterwards,
4-axis double-sided polishing machine for compound adhered to laminated plate surface {(Ltd.)
Removed by buffing using "Ishii Inscription", acid resistant ink {"PER-143B-5" manufactured by Goyou Chemical Co., Ltd.}
Was printed and cured by UV exposure. Then 50
The exposed copper portion was removed by etching with a ferric chloride etching solution at ℃, and after washing with water, the hole filling ink and the acid resistant ink were removed by spraying with a 3% aqueous solution of sodium hydroxide to prepare a double-sided printed wiring board.

On the other hand, with respect to the hole filling inks of Comparative Examples 1 and 3, the double-sided copper clad laminate having the through holes formed was immersed in the hole filling ink according to the process shown in FIG. 1 to fill the hole. After filling with ink, take it out,
The hole filling ink adhering to both sides of the laminate was scraped off with a urethane squeegee. Subsequently, this laminated plate was exposed under the conditions shown in Table 2 using a high pressure mercury lamp, and the hole filling ink was cured by photopolymerization from both sides. Then, the compound adhering to the surface of the laminated plate was removed by buffing using a 4-axis double-sided polishing machine {manufactured by Ishii Notation Co., Ltd.}, and acid-resistant ink {"PER-143B-5" manufactured by Mutano Chemical Industry Co., Ltd.}. Was printed and cured by UV exposure. Then, the exposed copper portion is removed by etching with a ferric chloride etching solution at 50 ° C., and after washing with water, the hole-filling ink and the acid-resistant ink are removed by spraying with a 3% sodium hydroxide aqueous solution to obtain a double-sided printed wiring board. It was created.

Further, regarding the hole filling ink of Comparative Example 2, the double-sided copper clad laminate having through holes formed therein was dipped in the hole filling ink according to the process shown in FIG. 1, and the hole filling ink was filled in the through holes. After filling, the ink was taken out, and the hole filling ink adhering to both surfaces of the laminate was scraped off with a urethane squeegee. Subsequently, this laminated plate was heated under the conditions shown in Table 2 to cure the hole-filling ink by heat polymerization. Then, the compound adhering to the surface of the laminated plate was removed by buffing using a four-axis double-sided polishing machine {made by Ishii Inscription}, and acid resistant ink {PERO-14 manufactured by Mutano Chemical Co., Ltd.
3B-5 "} was printed and cured by UV exposure.
Then, the exposed copper portion is removed by etching with a ferric chloride etching solution at 50 ° C., and after washing with water, the hole-filling ink and the acid-resistant ink are removed by spraying with a 3% sodium hydroxide aqueous solution to obtain a double-sided printed wiring board. It was created.

[0052]

[Table 1]

[0053]

[Table 2]

Each of the hole-filling inks of Examples 1 to 6 and Comparative Examples 1 to 3 was tested for each test item of filling rate, polishing property, etching suitability and dissolution removal time. Examples 1 to 6 were generally better than Comparative Examples 1 to 3, particularly those containing a large amount of component (D), and further those containing component (E) exhibited excellent test results for all test items. On the other hand, in Comparative Examples, the ultraviolet curable hole-filling ink containing the component (D) which is substantially opaque to ultraviolet rays is not practical because of poor curing, and the heat-polymerizable hole-filling ink contains a component (D). Those containing a large amount of D) have problems with respect to filling rate and proper etching.

For the hole-filling ink of Comparative Example 3, the following test was conducted separately. That is, according to the process shown in FIG. 1, a double-sided copper clad laminate having through holes formed therein is dipped in the filling ink to fill the filling ink into the through holes and then taken out to fill the holes on both sides of the laminated plate. The ink was scraped off with a urethane squeegee.
Then, using a high-pressure mercury lamp, this laminated plate was
Exposure was performed at 000 mj, and the hole filling ink was cured by photopolymerization from both sides. After that, the uncured hole-filling ink was removed, and the thickness of the remaining hardened part was measured with a micrometer. As a result, it was 6 μm on each surface, and most of the hole-filling ink in the through holes was uncured. There was found.

[0056]

EFFECTS OF THE INVENTION Since the hole-filling ink for producing a copper through-hole printed wiring board according to the present invention is constructed as described above, by adopting a curing step consisting of pre-curing with ultraviolet rays and subsequent thermal polymerization by heat treatment. Excellent in polymerizability due to poor oxygen polymerization, no volume shrinkage due to evaporation of volatile components during heating, excellent in through hole protection and through hole edge covering function, and easily removed by alkaline aqueous solution can do.

By mixing an inert solid powder in the hole filling ink according to the present invention, unnecessary hardened portions can be easily removed by buffing or the like after the step of hardening the hole filling ink. Further, the hole-filling ink is excellent in curability inside the through-hole, even if it is blended with an inert solid powder that is substantially opaque to ultraviolet rays,
A coloring pigment such as titanium oxide can be blended, and it is extremely effective especially for improving the visibility when inspecting the filling condition of the circuit board.

As a result, the high-density copper through-hole printed wiring board having a line width of 100 to 200 μm, which was conventionally produced only by a high-cost manufacturing method using a dry film resist or the like, maintains high reliability. At the same time, it can be manufactured at low cost, and defective products can be removed very easily during inspection.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of relevant parts for sequentially explaining a specific example of a method of using hole-filling ink according to the present invention.

[Explanation of symbols]

 1 Insulating substrate 2 Through hole 2a Through hole edge part 3 Copper plating layer 4 Hole filling ink 5 Etching resist layer

[Procedure amendment]

[Submission date] April 25, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction content]

[Synthesis Example 1] 154 g (1 mol) of hexahydrophthalic anhydride, 116 g (1 mol) of 2-hydroxyethyl acrylate, 0.1 g of N, N-dimethylbenzylamine and 0.1 of hydroquinone monomethyl ether.
g was placed in a flask equipped with a stirrer and reacted at 95 ° C. for 24 hours while blowing air until the peak of anhydrous acid in the infrared absorption spectrum disappeared to obtain a monoester compound (A-1).

Claims (7)

[Claims] 1. (A) The following general formula [I] or [II]: [Chemical 2] {In the formula, R ₁ is hydrogen or a methyl group, R ₂ is hydrogen or an alkyl group having 1 to 4 carbon atoms, Y is an alkylene group having 1 to 4 carbon atoms, or-(C _n H _2n O) _P --CH _2- (In the formula, n is 2 to
An integer of 6 and p is an integer of 1 to 19. ) Represents a group represented by. } A copper through-hole printed wiring containing 1 to 90% by weight of a monoester compound represented by the formula (B), 0.01 to 20% by weight of a thermal polymerization catalyst (B) and 0.01 to 20% by weight of a (C) photopolymerization catalyst. Filling ink for board manufacturing. 2. The hole-filling ink for producing a copper through-hole printed wiring board according to claim 1, which comprises (D) an inert solid powder. 3. The hole-filling ink for producing a copper through-hole printed wiring board according to claim 2, wherein the component (D) is an inert solid powder which is substantially opaque to ultraviolet rays. 4. The hole-filling ink for producing a copper through-hole printed wiring board according to claim 2, wherein the component (D) is titanium oxide which is substantially opaque to ultraviolet rays. 5. The method according to claim 1, which comprises (E) at least one resin compound selected from the group consisting of a phenol resin, a cresol resin and a rosin resin having an acid value of 50 to 500. Copper through-hole filling ink for printed wiring board manufacturing. 6. The component (E) has a softening point of 60 ° C. or higher and an acid value of 5.
The hole filling ink for producing a copper through-hole printed wiring board according to claim 5, which is a rosin-based resin of 0 to 500. 7. The copper through-hole printed wiring according to claim 1, 2, 3, 4, 5, or 6, wherein the step of curing the ink in the through-hole comprises pre-curing with ultraviolet rays and subsequent thermal polymerization by heat treatment. Method of using hole filling ink for substrate manufacturing.