JP2003330188A - Composition for negative electrodeposition photoresist, electrodeposition liquid comprising by using the same and electrodeposition coating film formed from the liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeposition coating film which is uniform on a fine substrate and does not exposure the edge part of the objective material and to provide an electrodeposition liquid for a negative resist and an electrodeposition liquid composition to form the coating film. <P>SOLUTION: The electrodeposition coating film is formed by using the following negative electrodeposition photoresist liquid. The electrodeposition liquid is prepared by using (a) cationic water-soluble or water-dispersible (meth)acrylic resin, (b) polyfunctional (meth)acrylic monomer, (c) photopolymerization initiator, (d) neutralizing agent for the component (a), (e) organic solvent and (f) deionized water and by controlling the maximum difference in the hysteresis loop of shear stress of the composition consisting of the components (a), (b) and (c) to more than 3 mN/cm<SP>2</SP>and less than 10 mN/cm<SP>2</SP>. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a negative-type electrodeposition photoresist composition, an electrodeposition liquid constituted by using the same, and an electrodeposition coating film formed by the same.

[0002]

2. Description of the Related Art Conventionally, anionic and cationic photoresist electrodeposition solutions have been used for etching applications, plating mask applications, and microfabrication applications for printed circuit boards and the like (for example, JP-A-61-80240). , JP-A-62-262855, JP-A-1-19179.
9 and JP-A-4-228598).

[0003]

[Problems to be Solved by the Invention]
A voltage is applied to the object to be coated to deposit the resin. However, at this time, electrolysis of water also occurs, and oxygen gas is generated at the anode and hydrogen gas is generated at the cathode. This generated gas remains in the deposited coating film and becomes a pinhole. As a countermeasure, the pinholes are eliminated by heating the object to be coated after electrodeposition of the coating film and leveling the coating film simultaneously with drying.

However, when the drying temperature is raised in order to solve the pinhole, the coating film is leveled on the flat portion of the object to be coated, but the edge portion of the object to be coated has a thin coating film, and the edge portion is thinned in a later step. There was a new problem that the part was exposed and the purpose as a resist could not be achieved.

As a countermeasure against this, a method of adding powders, pigments, fine particles or the like to the electrodeposition liquid for the purpose of adjusting the fluidity of the electrodeposition coating film (for example, JP-A-63-235496 and JP-A-1). However, these methods are not complete solutions because the added powder and pigment precipitate and aggregate.

Further, the use of thickeners such as polycarboxylic acids and waxes has been investigated in order to suppress the sedimentation of additives, but there has been a problem that the chemical resistance of the coating film deteriorates.

The present invention solves the above-mentioned problems in the prior art, and forms a negative electrodeposition photoresist on a fine substrate in which the coating film formed is uniform and the edges are not exposed. It is intended to provide a composition for use, an electrodeposition liquid constituted by using the composition, and an electrodeposition coating film formed by the composition.

[0008]

In order to achieve the above object, the inventors of the present invention have conducted extensive studies and as a result, as the main resin composition constituting the electrodeposition liquid, one having a high thixotropic property was used. By doing so, we have found that the fluidity of the coating film during drying can be controlled, so that an electrodeposition coating film can be obtained in which the edges of parts requiring fine processing are not exposed,
The present invention has been completed.

The present invention made on the basis of the above-mentioned findings is based on the water-soluble or water-dispersible (meth) acrylic resin 38.
~ 94 parts by weight and 5-5 polyfunctional (meth) acrylic monomers
0 parts by weight and 1 to 12 parts by weight of the photopolymerization initiator, the heating residue is 40 ± 2% by weight, the measurement temperature is 60 ± 1 ° C., and the shear rate is 0.
The maximum value of the hysteresis loop difference of the shear stress is 3 mN / cm ² when measured under the conditions of up to 20 (sec ⁻¹ ).
It is a gist of a negative electrodeposition photoresist composition which is more than 10 mN / cm ^{2 and more} than 10 mN / cm ² .

Furthermore, the gist of the present invention is a negative electrodeposition photoresist liquid comprising a neutralizing agent, an organic solvent and deionized water in addition to the resin composition. The water-soluble or water-dispersible (meth) acrylic resin has an amine value of 10 to 10.
Having 100 mgKOH / g is also the gist. Furthermore, the gist of the present invention is an electrodeposition coating film formed by the electrodeposition liquid.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The structure and operation of the present invention will be specifically described, but the present invention is not limited thereto. In the present invention, each component of (a) water-soluble or water-dispersible (meth) acrylic resin, (b) polyfunctional (meth) acrylic monomer, and (c) photopolymerization initiator is a negative type. It is an essential constituent for obtaining an electrodeposition photoresist solution.

As the amino group-containing monomer constituting the water-soluble or water-dispersible (meth) acrylic resin as the component (a), dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, ( Examples include dimethylaminopropyl (meth) acrylate and acrylamide.

The monomers to be copolymerized with the amino group-containing monomer include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate and n-
Propyl acrylate, n-propyl methacrylate,
Isopropyl acrylate, isopropyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, hexyl acrylate, hexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, heptyl acrylate, heptyl methacrylate, and other hydroxyl groups. 2-Hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomer Acrylate and the like can be used.

As the polymerization initiator, there are azo compounds such as 2.2-azobisisobutylnitrile and peroxide compounds such as benzoyl peroxide. Examples of the polymerization regulator include dodecyl mercaptan and the like.

Next, as the polyfunctional (meth) acrylic monomer as the component (b), bisphenol F epoxy modified diacrylate, bisphenol A epoxy modified diacrylate, isocyanuric acid epoxy modified diacrylate, polypropylene glycol diacrylate, pentaerythritol. Diacrylate monostearate, polyethylene glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolpropane propylene oxide triacrylate, isocyanuric acid epoxy modified triacrylate, trimethylolpropane epoxy modified triacrylate, dipentaerythritol pentaacrylate ,
One or more of dipentaerythritol hexaacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate and the like can be used.

Further, as the photopolymerization initiator of the component (c), dimethylaminobenzoic acid derivative, acetophenone derivative, benzophenone derivative, benzoin derivative, alkylphenone derivative, thioxanthone derivative, sulfonylazidebenzoic acid, diazodiphenylamine derivative, naphthoquinonediazosulfone are used. One kind or two or more kinds of derivatives can be used.

Acids necessary for neutralizing the component (d) include formic acid, acetic acid, propionic acid, lactic acid, 2-ethylbutanoic acid,
Organic acids such as octyl acid, sulfuric acid, phosphoric acid, etc. can be used.

Examples of the organic solvent as the component (e) include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol and pentanol, ethylene glycol methyl ether. , Ethylene glycol ethyl ether, ethylene glycol ethyl ether acetate, ethylene glycol-n-butyl ether, ethylene glycol-tert-butyl ether, ethylene glycol-n-hexyl ether, ethylene glycol-2-ethylhexyl ether, etc. cellosolves, ethylene glycol-n -Butyl ether acetate, diethylene glycol-n-butyl ether, diethylene glycol-n-hexyl ether, propylene glycol Chill ether, propylene glycol ethyl ether, propylene glycol-n-propyl ether, propylene glycol-n-butyl ether, propylene glycol phenyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol diacetate, dipropylene glycol methyl ether, Dipropylene glycol ethyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n-butyl ether and the like can be used.
In addition, dyes and pigments can be used for coloring.

38 to 94 parts by weight of the water-soluble or water-dispersible (meth) acrylic resin (a) component in the present invention,
The heating residue of a negative electrodeposition photoresist composition comprising 5 to 50 parts by weight of component (b) and 1 to 12 parts by weight of component (c), totaling 100 parts by weight, is 40 ± 2% by weight, and the measurement temperature is 6
Shear rate is 0 → 20 → 0 (sec ⁻¹ ) at 0 ± 1 ℃
The maximum value of the hysteresis loop differential shear stress when changing exceeds the 3 mN / cm ^2, for a range of less than 10 mN / cm ^2, which electrodeposition coating film formed by the configured electrodepositing solution by the It is uniform and the edges are not exposed.

To measure the viscoelasticity of this composition, a sample is placed in a cell as shown in FIG. 1, the ambient temperature is kept constant, and then the lower shaft is rotated. Measure the torque of the upper shaft at that time,
The shear stress is calculated from it.

When the maximum value of the hysteresis loop difference of shear stress is 3 mN / cm ² or less, the edge portion is exposed and 1
When it is 0 mN / cm ² or more, the production becomes difficult because of high viscosity. For such a commentary on the viscoelasticity of polymer components, "Rheology for Chemists" by Shigeharu Onoki,
(September 1982, published by Kagaku Dojin).

As a result of intensive studies, it was found that the thixotropy of the electrodeposition coating film becomes large when a large amount of MMA component is present in the monomer of the acrylic resin raw material. However, due to the influence of other monomer components, it was concluded that it is difficult to specify the composition ratio of the composition.

The water-soluble or water-dispersible (meth) acrylic resin (a) component of the present invention has an amine value of 10 to 1
The electrodeposition liquid obtained in the range of 00 mgKOH / g has particularly good water dispersibility. If the amine value is less than 10 mgKOH / g, the water dispersibility is poor, and if it is 100 mgKOH / g or more, the chemical resistance of the electrodeposition coating film against the plating solution or the etching solution is poor.

As the electrodeposition condition using the electrodeposition liquid according to the present invention, the voltage applied in the energizing step is 1
It is 5 to 250 V, preferably 60 to 160 V, and the energization time is 10 to 180 seconds, preferably 10 to 60 seconds. The applied voltage may be either a hard start in which a set voltage is applied at the same time as energization or a soft start in which the set voltage is gradually increased.

The object to be coated by electrodeposition is washed with water, then dried to remove water and solvent components in the coating film, and then exposed to ultraviolet rays for exposure. The high-pressure mercury lamp or the metal halide lamp may be used as the ultraviolet light source. The amount of light for exposure is 50 mJ / cm ^{2 to} 1000 m
J / cm ² , preferably 200 to 300 mJ / cm ²
Is.

The exposure is performed through the mask pattern, and a predetermined pattern is printed on the coating film. Further, in order to increase the resolution of the pattern, it is preferable that the mask pattern is brought into direct contact with the coating film.

The exposed coating film is developed with an organic acid type developing solution to dissolve and remove the unexposed portion. This developer is
Organic acid such as formic acid, acetic acid, lactic acid and the like made into an aqueous solution of about 1 to 5% is in the range of room temperature to 50 ° C., preferably 35 to 50 ° C.
Use in the range of 45 ° C. If necessary, a nonionic surfactant may be added to shorten the development time.

After development, the article to be coated is plated or etched. After that, if the electrodeposition coating film is unnecessary, the coating film is peeled and removed with a peeling liquid.

The object to be coated to which the present invention can be applied is not particularly limited as long as it is not only an electronic component for microfabrication such as a printed circuit board, a lead frame, a connector terminal, etc. but also a microfabrication for which conductivity is present. It can be used as a plating resist or etching resist. For example,
IT that can simultaneously impart transparency and conductivity
It may be on a glass plate on which O (Indium Tin Oxide) is vapor-deposited.

Regarding the use of the electrodeposition liquid of the present invention, it may be blended with other electrodeposition liquid depending on the application. Furthermore, even if the (meth) acrylic resin is not the cation type as in the present invention but an anion type, it can be used similarly.

[0031]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The parts in the examples and comparative examples are parts by weight unless otherwise specified.

Production Example 1 Production of Water-Soluble or Water-Dispersible Vinyl Copolymer A 3 liter four-necked flask equipped with a stirrer, a reflux device and a nitrogen inlet tube was charged with 3 parts by weight of isopropyl alcohol.
0 part was charged and the temperature was raised to 80 ° C. Separately, 10 parts of isopropyl alcohol, 8 parts of dimethylaminoethyl acrylate, 24 parts of 2-ethylhexyl acrylate, 68 parts of methyl methacrylate, 1 of azobisisobutyronitrile
1 part of the mixed solution was placed in a dropping funnel and placed in the flask.
It dripped over 20 minutes. After the completion of the dropping, 3 parts of isopropyl alcohol and azobisisobutyronitrile were further added.
After adding 5 parts 3 times every 30 minutes, 1 more at 90 ° C
The reaction was continued for 80 minutes.

Production Example 2 Production of Water-Soluble or Water-Dispersible Vinyl Copolymer A 3 liter four-necked flask equipped with a stirrer, a reflux device and a nitrogen inlet tube was charged with 3 parts by weight of isopropyl alcohol.
0 part was charged and the temperature was raised to 80 ° C. Separately, 10 parts of isopropyl alcohol, 10 parts of diethylaminoethyl methacrylate, 5 parts of 2-ethylhexyl acrylate, 5 parts of 2-ethylhexyl methacrylate, 5 parts of ethyl acrylate, 18 parts of butyl acrylate, 57 parts of methyl methacrylate and 1 part of azobisisobutyronitrile. The mixed solution was charged into a dropping funnel and added dropwise into the flask over 120 minutes. After completion of the dropping, 30 parts of 3 parts of isopropyl alcohol and 0.5 part of azobisisobutyronitrile were further added.
After adding 3 times every minute, the reaction was continued at 90 ° C. for 180 minutes.

Production Example 3 Production of Water-Soluble or Water-Dispersible Vinyl Copolymer A 3 liter four-necked flask equipped with a stirrer, a reflux device and a nitrogen inlet tube was charged with 3 parts by weight of isopropyl alcohol.
0 part was charged and the temperature was raised to 80 ° C. Separately, 10 parts of isopropyl alcohol and 8 parts of dimethylaminoethyl acrylate
Part, ethyl acrylate 47 parts, methyl methacrylate 45 parts, and azobisisobutyronitrile 1 part were mixed in a dropping funnel and added dropwise into the flask over 120 minutes. After the dropping was completed, 3 parts of isopropyl alcohol and 0.5 part of azobisisobutyronitrile were further added 3 times every 30 minutes, and the reaction was further continued at 90 ° C. for 180 minutes.

Production Example 4 Production of Water-Soluble or Water-Dispersible Vinyl Copolymer A 3 liter four-necked flask equipped with a stirrer, a reflux device and a nitrogen inlet tube was charged with 3 parts by weight of isopropyl alcohol.
0 part was charged and the temperature was raised to 80 ° C. Separately, 10 parts of isopropyl alcohol and 8 parts of dimethylaminoethyl acrylate
Part, butyl acrylate 33 parts, methyl methacrylate 59 parts, and azobisisobutyronitrile 1 part were mixed in a dropping funnel and added dropwise into the flask over 120 minutes. After the dropping was completed, 3 parts of isopropyl alcohol and 0.5 part of azobisisobutyronitrile were further added 3 times every 30 minutes, and the reaction was further continued at 90 ° C. for 180 minutes. Table 1 shows the compounding ratio of each production example.

[0036]

[Table 1]

Example 1 To 151.5 parts of the acrylic copolymer of Production Example 1, 25 parts of dipentaerythritol penta and hexaacrylate (Aronix M-400 manufactured by Toagosei Co., Ltd.), 2
-Methyl-1 [4- (methylthio) phenyl] -2-monofolinopropan-1-one (Ciba Geigy Corp.)
Irgacure 907) 5 parts, 2,4-diethylthioxanthone (Kayakyu DETX-S manufactured by Nippon Kayaku Co., Ltd.)
2 parts, propylene glycol monomethyl ether 16
And 80 parts of 80% lactic acid were added and sufficiently stirred, then 127.5 parts of deionized water was added to give a solution having a heating residue of 40%. Further, deionized water was added so that the heating residue was 10% to prepare an electrodeposition liquid.

Comparative Example 1 to Comparative Example 3 Regarding Comparative Examples 1 to 3, the acrylic copolymer used in Example 1 was the same as Production Example 2 in Comparative Example 1, and Comparative Example 2 was used.
Each of the electrodeposition liquids was produced by the same method except that Production Example 3 was used, and Comparative Example 3 was Production Example 4.

Comparative Example 4 51.8 parts of dipentaerythritol penta and hexaacrylate (Aronix M-400 manufactured by Toagosei Co., Ltd.) were added to 181.8 parts of the acrylic copolymer of Production Example 1 above.
5 parts of methyl-1 [4- (methylthio) phenyl] -2-monofolinopropan-1-one (Irgacure 907 manufactured by Ciba Geigy), 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd.) Kayakyu DETX-S) 2
Parts, 16 parts of propylene glycol monomethyl ether,
After adding 3.6 parts of 80% lactic acid and stirring sufficiently, 116.6 parts of deionized water was added to obtain a solution having a heating residue of 40%.
Further, deionized water was added so that the heating residue was 10% to prepare an electrodeposition liquid. Table 2 (upper part) shows the mixing ratio of the electrodeposition liquid of Example 1 and each comparative example.

[0040]

[Table 2]

Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3
And a 40% heating residue solution prepared in Comparative Example 4,
The shear rate at 60 ° C. was 0 → 20 → 0 (se using an MR-3 liquid meter manufactured by Rheology Co., Ltd.).
The shear stress when changed to c ⁻¹ ) was measured (FIG. 2).

Using the electrodeposition solutions prepared in Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3, a copper plate was used as an anode and the solution temperature was 45.
The electrodeposition coating film was deposited by energizing at 100 ° C for 1 minute at 100V, washed with water, and dried at 70 ° C for 10 minutes to obtain a coating film having a thickness of 10 µm.

Both sides were exposed through the mask pattern with a 2 kw high-pressure mercury lamp at 300 mJ / cm ² . Next, the unexposed area was washed off with a 1% lactic acid solution at 40 ° C. and developed. The coated article thus obtained was observed with a stereoscopic microscope and a scanning electron microscope at a magnification of 100 times. A comparison between Example 1 and Comparative Example 1 at that time is shown in FIG. 3 as a schematic diagram.

The viscosity curves of the 40% heating residue solutions of Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3 are shown in FIG. The electrodeposition results are shown in Table 2 (bottom).

[0045]

EFFECTS OF THE INVENTION The present invention has the constitution described above, and thus the formed electrodeposition coating film is uniform even on a fine substrate,
It has an excellent effect that the edge portion is not exposed, and is extremely useful in industry.

[Brief description of drawings]

FIG. 1 is a conceptual explanatory view of a mechanism for measuring viscoelasticity of an electrodeposition liquid.

FIG. 2 is a graph showing measurement results of viscoelasticity of electrodeposition liquids of Examples and Comparative Examples.

FIG. 3 is a comparative schematic explanatory view of the edge covering property of the electrodeposition coating film.

Continued front page    F term (reference) 2H025 AA13 AA18 AB15 AC01 AD01                       BC13 BC42 BJ07 CB51 CB53                       CC03                 4J011 AC04 HA04 PA69 QA17 QA23                       QA24 QA25 QB16 QB19 QB20                       SA01 SA21 SA31 SA64 SA80                       SA82 SA83                 4J026 AA45 AC26 BA28 BB01 DA02                       GA07

Claims (4)

[Claims] 1. (a) Water-soluble or water-dispersible (meth)
A composition comprising 38 to 94 parts by weight of an acrylic resin, 5 to 50 parts by weight of a (b) polyfunctional (meth) acrylic monomer, and 1 to 12 parts by weight of a (c) photopolymerization initiator, the heating residue of which is Four
0 ± 2% by weight, measurement temperature 60 ± 1 ° C, shear rate 0-2
0 when measured under the conditions of ^{(sec -1),} a negative type electrodeposition photoresist maximum value of the hysteresis loop difference of the shear stress exceeds the 3 mN / cm ^2, and less than 10 mN / cm ² Composition. 2. (a) Water-soluble or water-dispersible (meth)
Acrylic resin has an amine value of 10-100 mgKOH / g
The composition for negative electrodeposition photoresist according to claim 1, which comprises: 3. A negative electrodeposition photoresist composition comprising (a) component, (b) component and (c) component according to claim 1 or 2, and (d) and (a). A negative electrodeposition photoresist liquid comprising a component neutralizing agent, (e) an organic solvent, and (f) deionized water. 4. An electrodeposition coating film formed by the electrodeposition photoresist liquid according to claim 3.