JPS636070A - Positive photosensitive electrodeposition coating - Google Patents

Abstract

PURPOSE:To obtain the title coating which has excellent ultraviolet sensitivity and can form a developable film uniformly on, e.g., a copper-clad laminate, by using as its principal component an ortho-quinone diazide compound having amino and diazide groups, or an adduct of this compound with an organic resin. CONSTITUTION:A cationic electrodeposition coating consisting mainly of an ortho-quinone diazide compound having amino and diazide groups, or an adduct of this compound with an organic resin. The ortho-quinone diazide compound to be used is a compound having primary to tertiary amino groups together with diazide groups in a molecule, whose examples include compounds of formulas I, II and III. As the organic resin, for example, a bisphenol epoxy resin or an acrylic resin having glycidyl groups is suitably used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a positive-type photosensitive electrodeposition paint, and more specifically, it can be electrodeposited on a copper-clad laminate to form a smooth, non-adhesive coating, and can be easily coated with ultraviolet light through the positive. The present invention relates to a cationic electrodeposition coating composition suitable for use in printed wiring 2-odd resists that are sensitive to light.

Conventionally, printed wiring boards for integrated circuits, etc., are generally made by applying copper plating to a laminated board made of copper foil on an insulator, laminating a photosensitive film on top of this, and then layering a photographic negative and exposing it to light. After development, unnecessary copper foil other than the circuit pattern is etched, and the photosensitive film is then removed. However, since this photosensitive film is generally as thick as 50 μm, the circuit pattern formed by exposure and development is not sharp, and it is difficult to laminate it uniformly on the copper foil surface, especially when covering through-hole areas. That is almost impossible.

On the other hand, methods for producing printed wiring boards include negative photoresist and positive photoresist. That is, the former method uses a composition that hardens upon light irradiation and develops by dissolving and removing the unexposed areas, while the latter method uses a compound such as an orthoquinone diazide compound that increases its solubility in an alkaline aqueous solution when exposed to light. , a method of developing by dissolving and removing the exposed area. In both of these methods, the former is difficult to cure in areas where the exposure amount is weak. In particular, in order to form a resist film on through holes, it is necessary to irradiate with strong light for a long time, which is inefficient, and the diameter is small. and difficult to cure. - On the other hand, in the latter case, the unexposed part remains as a resist film, so it is easier to form a resist film on the through-hole part compared to the former, but it is still not sufficient for practical use.
Moreover, it has problems such as insufficient image resolution and high manufacturing cost.

The present invention was made for the purpose of solving the various problems mentioned above in producing printed wiring boards, and as a result, it has excellent ultraviolet sensitivity, and moreover, the surface of copper-clad laminates and through-holes can be easily developed. The object of the present invention is to provide a cationic electrodeposition coating composition for printed wiring positive type photoresists that can form a uniform coating film.

Therefore, according to the present invention, there is provided a positive type photosensitive cationic electrodeposition paint containing as a main component an orthoquinonediazide compound having an amino group and a diazide group or an adduct of the orthoquinonediazide compound and an organic resin.

The orthoquinonediazide used in the present invention includes:
Specific examples include compounds having the following structural formula, but the present invention is not limited thereto.

H3 UL; 2H H3 Among the above, ■ to ■ are primary amino groups, ■ to O are secondary amino groups, and @ to [stock] is an orthoquinone diazide compound having a tertiary amino group. .

These orthoquinone diazide compounds preferably contain 0.5 amines.

Further, examples of adducts of the above-mentioned orthoquinoline diazide compound and organic resin include those illustrated below.

Organic resins include glycidyl groups (including epoxy groups)
Examples include bisphenol-type epoxy resins, aliphatic-type epoxy resins, acrylic resins or polyester resins containing glycidyl groups,
Ethylene oxide, propylene oxide, styrene oxide, phenyl glycidyl ether and the like are suitable. Regarding this glycidyl group-containing organic resin, the number average molecular weight is preferably 40 to 5oooo, particularly 60 to 20,000, and the epoxy equivalent is 40 to 2,500, particularly 6
A value of 0-1500 is suitable.

The orthoquinolinediazide compounds to be added to these glycidyl group organic resins are those listed above.
It is preferable to use a compound having a primary or secondary amino group and a diazide group such as.

The addition reaction between these two components takes place between the glycidyl group in the organic resin and the amino group in the orthoquinone diazide compound.These addition reactions easily react at room temperature, but as it is an exothermic reaction, cooling is required. It is preferable to do this while

Furthermore, in the present invention, as the organic resin to which the orthoquinolinediazide compound is added, in addition to the above, one type selected from an amino group (primary to tertiary), or an amino group and a hydroxyl group, a glycidyl group, an incyanate group, etc. Organic resins containing the above functional groups can also be used, specifically epoxy resins that have these groups by methods known per se,
Examples include acrylic resin, polyester resin, polyurethane resin, etc., and the number average molecular weight of the organic resin is 100 to 5.
Preferably, it is 0000.

The orthoquinoline diazide compound added to these organic resins has a sulfonic acid group (-503
Specifically, those having (7) functional groups such as H), sulfonic acid chloride (S02C1), and hydroxyl group (-OH) are preferable.

■1.2-benzoquinonediazide sulfonic acid chloride, [phase] 1.2-benzoquinonediazide-4-(1-hydroxyethyl)-sulfonic acid amide, [phase] 1.2-naphthoquinonediazide-5-sulfonic acid chloride, etc. can be given.

The reaction between the above organic resin and the orthoquinoline diazide compound is an addition reaction or condensation reaction between a glycidyl group and a sulfonic acid group, a hydroxyl group and a sulfonic acid chloride, a primary or secondary amino group and a sulfonic acid chloride, an incyanate group and a hydroxyl group, etc. As a specific example, the above-mentioned
The above [phase] compound was added to a polyurethane resin having tertiary amino groups and incyanate groups, and the above [phase] compound was added to an acrylic resin having primary and secondary 7-mino groups. Examples include products to which each compound is added.

The addition reaction product of both components preferably contains 0.04 to 0.54 orthoquinone diazide groups per molecular weight of 100, and has an amino value of 30 to 250.

The positive-type cationic electrodeposition paint of the present invention neutralizes the amino groups of the above-mentioned orthoquinoline diazide compound and/or the adduct of the compound and an organic resin with an organic acid or an inorganic acid,
Obtained by dispersing or dissolving in water.

Examples of organic acids used for neutralization include acetic acid and lactic acid, and examples of inorganic acids include phosphoric acid.The neutralization amount is preferably in the range of 0.1 to 1.0 equivalents, and if the amount is less than 0.1 equivalents, water dispersibility may decrease. If the amount decreases, electrodeposition coating becomes difficult, and if the amount exceeds 1.0 equivalent, storage stability may deteriorate.

In the present invention, in order to further improve the fluidity of the water-solubilized or water-dispersed paint, hydrophilic solvents (e.g., impropatol, n-butanol, t-butanol, methoxyethanol, ethoxyethanol, butoxyethanol, diethylene glycol, methyl ether, dioxane, tetrahydrofuran, etc.). The amount of the hydrophilic solvent used is preferably 300 parts by weight or less per 100 parts by weight of the orthoquinoline diazide compound or adduct.

In order to increase the amount of coating on the object, use hydrophobic solvents (for example, petroleum solvents such as toluene and xylene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and butyl acetate, and °2-ethylhexyl). Alcohol (alcohols, etc.) can also be added. The amount of the hydrophobic solvent used is preferably 200 parts by weight or less per 100 parts by weight of the orthoquinoline diazide compound or adduct.

Furthermore, if necessary, resins other than the organic resins having functional groups mentioned above, such as acrylic resins, phenolic resins, polyurethane resins, etc., can be blended to adjust the performance of the electrodeposition coating film as appropriate, and the blending amounts of these resins are as follows: , 100 parts by weight or less per 100 parts by weight of the orthoquinolinediazide compound and/or the addition resin. Furthermore, dyes and pigments can also be added.

A printed wiring board using the cationic electrodeposition paint of the present invention is produced as follows.

A cationic electrodeposition paint bath containing the above-mentioned orthoquinone diazide compound and/or a neutralized product of an adduct of the compound to an organic resin as a main component was prepared at a pH of 3 to 9 and a bath concentration (solid content concentration) of 3.
~30% by weight, preferably 5-15% by weight, bath temperature 15
The temperature is controlled at ~40°C, preferably 15-30°C. Then,
A printed wiring board made of an insulating plate covered with copper foil and copper-plated was immersed in this electrodeposition paint bath as a cathode, and
The 0-current application time, which is carried out by applying a direct current of 400 V, is suitably 30 seconds to 5 minutes, and the dry film thickness is desirably 2 to 100<-1>, preferably 3 to 20<->.

After electrodeposition coating, the object to be coated is taken out of the electrodeposition bath and washed with water, and then the moisture contained in the electrodeposition coating is removed with hot air or the like.

Next, a pattern mask (photographic negative) is placed on the surface of the photosensitive electrodeposition coating film thus formed, and only unnecessary parts other than the conductor circuit (circuit pattern) are exposed to active light such as ultraviolet rays. Since the orthoquinone diazide compound in this exposed area becomes a carboxylic acid via ketene, it is removed by a developing process using a developer such as an aqueous alkaline solution, and high resolution can be achieved.

In the present invention, the active light rays used for exposure are 3000 to 4
Light having a wavelength of about 500 nm is preferred; these light sources include sunlight, mercury vapor lamps, xenon lamps, arc lamps, etc. Irradiation with actinic rays is usually carried out for a period of 1 second to 20 minutes.

In addition, the development process is carried out by spraying weak alkaline water onto the coating surface to wash away the exposed areas of the coating film.The weak alkaline water is usually contained in the coating film, such as caustic soda, soda carbonate, caustic potash, or aqueous ammonia. Those that can be neutralized with free carboxylic acid to provide water solubility can be used.

Next, the copper foil part (
The non-circuit portions) are removed by a conventional etching process using, for example, a mixed solution of ammonium hydroxide and ammonium chloride. After that, the unexposed coating film on the circuit pattern is also treated with cellosolve solvents such as ethyl cellosolve and ethyl seron rub acetate, aromatic hydrocarbon solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and ethyl acetate. , an acetate-based solvent such as butyl acetate, or a chlorine-based solvent such as trichloroethylene to form a printed circuit on the board.

[Function] The positive photosensitive cationic electrodeposition paint of the present invention can be easily cationically electrodeposited onto copper foil, and the deposited coating film is dried to form a uniform photoresist film. When this photosensitive film is irradiated with light through a positive film, the exposed areas change as described above and are developed with weak alkaline water, and the unexposed areas can also be dissolved and removed with a solvent, so they can be replaced with conventional photosensitive films. Can be done.

In particular, the electrodeposition paint of the present invention is optimal for manufacturing printed circuit boards having through-holes, and when a photosensitive dry film is used, there is no need for a solder plating process, and the printed circuit board manufacturing process can be shortened. In addition, it is difficult to form a cured film on small-diameter through-holes with photocurable electrodeposition paint, but with the present invention, the unexposed areas remain as a resist film, making it suitable for manufacturing printed circuit boards with small diameters. There is.

Examples related to the present invention will be described.

Example 1 A solution of ethylene glycol monoethyl ether (Epicor) 1001 was heated to 50°C, and the above-mentioned orthoquinonediazide compound was gradually added while maintaining the same temperature, and the mixture was reacted for 1 hour to form a positive photosensitive resin (amino value 69). ) was obtained.

Next, 22 parts by weight of acetic acid was added to 714 parts by weight of this photosensitive resin solution to sufficiently neutralize it, and then deionized water was added so that the solid content was 10% by weight, and an electrodeposition coating bath (pH 6, 2
).

Example 2 Epikote 828 380 parts by weight 1098 parts by weight A solution of Epikote 828 and ethylene glycol monoethyl ether was heated to 50°C, and the above orthoquinone diazide compound was gradually added while maintaining the same temperature, and the mixture was reacted for 1 hour to form a positive type. A photosensitive resin (amino value 76) was obtained.

After sufficiently neutralizing 24 parts by weight of acetic acid to 714 parts by weight of this photosensitive resin solution, deionized water was added so that the solid content was 10% by weight to prepare an electrodeposition coating bath (pH 6.1).

Example 3 43 parts by weight of methyl methacrylate, 15 parts by weight of butyl acrylate, 21 parts by weight of diethylaminoethyl methacrylate
A mixed solution consisting of 21 parts by weight of glycidyl methacrylate and 3 parts by weight of azobisisobutyronitrile was placed in 90 parts by weight of propylene glycol 7-methyl ether (hydrophilic solvent) maintained at 110°C under a nitrogen gas atmosphere for 3 hours. It took a while to drip. After that, it was aged for 1 hour, and a mixed solution consisting of 1 part by weight of azobisdimethylvaleronitrile and 10 parts by weight of propylene glycol monomethyl ether was added dropwise over 1 hour, and further aged for 5 hours to remove tertiary amino groups and glycidyl groups. Next, 27 parts by weight of 1,2-benzoquinonediazide sulfone was added to the solution containing the acrylic resin (amino value 73), and the mixture was reacted at 30°C for 1 hour to form a photosensitive resin (amino value 49Tg). A solution with a point of 45° C. and a number average molecular weight of 11,000 was obtained.

After 83 parts by weight of acetic acid was added to 693 parts by weight of this photosensitive resin solution to sufficiently neutralize it, deionized water was added so that the solid content was 10% by weight to prepare an electrodeposition coating bath (pH 6.4).

Example 4 Photosensitive resin solution of Example 3 582 parts by weight CH366
After sufficiently neutralizing 24 parts by weight of acetic acid to 684 parts by weight of a mixed solution consisting of 684 parts by weight, deionized water was added so that the solid content was 10% by weight to prepare an electrodeposition coating bath (pH 6.2). .

Example 5 30 parts by weight of acetic acid was added to 600 parts by weight of a mixed solution consisting of 200 parts by weight (200 parts by weight of ether solution) to sufficiently neutralize the mixture, and then diluted with deionized water to make the solid content 10% by weight, followed by electrodeposition coating. It was set as a bath (PH6, 0).

Example 6 After dissolving 500 parts by weight of the orthoquinone diazide compound having the chemical formula used in Example 4 in 150 parts by weight of ethylene glycol monoethyl ether, 39 parts by weight of acetic acid was added to sufficiently neutralize the solution, but the solid content was 10% by weight. The solution was diluted with deionized water to give an electrodeposition coating bath (pH 5, 4).

Application Examples Copper-clad laminates for printed wiring (240X170X1.
5+sm) was immersed as a cathode, and the bath temperature was 25°C.
Electrodeposition coating was carried out by applying a DC current of 500 V for 3 minutes. The coating film was washed with water and dried at 50° C. for 5 minutes to form a smooth, non-adhesive photosensitive film with a thickness of 5W. Next, a positive film was brought into close contact with the electrodeposited surface using a vacuum device, and both sides were irradiated with 150 mJ/cm'' using a 3KW ultra-high pressure mercury lamp.
Next, the exposed areas were washed with a 1% aqueous solution of sodium carbonate and developed. After washing with water, the copper foil was removed by etching (with a mixture of ammonium hydroxide and ammonium chloride), and the unexposed areas were etched with ethylene glycol monoethyl. By removing it with an ether solvent, a printed circuit board with a clean, sharp pattern was obtained, with copper foil also attached to the through holes.

Claims (1)

[Claims] A positive-type photosensitive cationic electrodeposition paint containing as a main component an orthoquinonediazide compound having an amino group and a diazide group, or an adduct of the orthoquinonediazide compound and an organic resin.