JPH0820735B2 - Photosensitive resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is particularly excellent as a photosensitive resin composition, more specifically, as an etching resist or a plating resist used in the production of printed wiring boards, precision processing of metals and the like. And a photosensitive resin composition having excellent adhesion and workability or high sensitivity.

(Prior Art) In the fields of printed wiring board manufacturing, precision processing of metals, etc., a photosensitive resin composition and a photosensitive resin composition are used as a resist material when a chemical or electrical method of a substrate such as etching or plating is used. It is known to use the photosensitive elements used. As the photosensitive element, one in which a photosensitive resin composition is laminated on a support is widely used.

Conventionally, there are two methods of manufacturing a printed wiring board, a tenting method and a plating method. The tenting method protects the copper through holes for chip mounting with resist,
The electric circuit is formed through etching and resist peeling, whereas the plating method uses electrical plating to deposit copper in the through holes and protects it with soldering. This is a method of forming an electric circuit.

Compared with the plating method, the tenting method does not have various steps such as degreasing, substrate cleaning, acid cleaning, and activation, and the resist does not come into direct contact with a strongly acidic or strongly basic aqueous solution.
Unnecessary troubles can be avoided in the manufacture of printed circuit boards,
In addition, the process is simple, which is industrially useful.

When an electric circuit is formed by a tenting method, the photosensitive resin composition is required to have a sufficient film strength to withstand the spray pressure of a developing solution or washing, and to have a desired film strength during etching. The resist shape is good for obtaining the line width, and the peeling pieces at the time of peeling are fine.

Normally, the peeling is performed by an automatic peeling machine. However, if the peeling piece is large, the roll of the peeling machine will be entangled with the peeling piece and the workability will be significantly deteriorated. The peeling piece is
Fineness is desirable. In addition, it is desirable that the resist shape is vertical and there is no cavity in the resist wall at the interface between the resist and the copper surface, from the viewpoint of line accuracy.
If the resist shape is trapezoidal, it will be difficult to achieve high resolution in terms of resolution, and if it is an inverted trapezoidal shape, the contact area with the copper surface will be relatively small and the adhesion of the resist during etching will be reduced. Become.

Particularly in the case of an alkali-developable photosensitive resin composition, the size of the peeling piece is determined by the composition or molecular weight of the film-imparting polymer used in the photosensitive resin composition. That is,
The smaller the molecular weight, the smaller the flakes, and the more hydrophilic the composition, the smaller the flakes.

On the other hand, the shape of the resist becomes worse as the hydrophilicity of the composition becomes higher, and if the hydrophilicity is too high, cavities will be seen in the sidewalls of the resist. A photosensitive resin material having a good resist shape and a fine peeling piece has not been supplied yet, and although it has a good resist shape, there are many large peeling pieces. If the roll is entangled, it is the current practice to remove the strips from the roll several times a day.

(Problems to be Solved by the Invention) As a result of repeated studies to solve the above-mentioned drawbacks, the present inventors have made a good resist shape,
Another object of the present invention is to provide a photosensitive resin composition in which the strips become fine during stripping.

(Means for Solving Problems) The present invention provides (A) 20 to 40% by weight of methacrylic acid, 5 to 30% by weight of styrene, and 30 to 75% by weight of a monomer represented by the general formula (I). Weight average molecular weight obtained as a polymerization component 10,000 to 50,0
Alkali-soluble vinyl copolymer compound (a) of 00, 20 to 40% by weight of methacrylic acid and 60 to 80% by weight of the monomer represented by the general formula (I) as a copolymerization component are obtained. 40 to 80 parts by weight of a film-forming polymer containing 150,000 alkali-soluble vinyl copolymer compound (b) (R ₁ means hydrogen atom or methyl group, R ₂ has 1 carbon atom
(B) an ethylenically unsaturated compound in an amount of 20 to 60 parts by weight (however, the sum of (A) and (B) is 100 parts by weight) (C) an organic halogen compound (A). ) And (B) total 100
0.2 to 10 parts by weight with respect to parts by weight (D) A sensitizer and / or a sensitizer system capable of generating free radicals by actinic rays is 0.5 to 100 parts by weight with respect to 100 parts by weight of the total of (A) and (B). The present invention relates to a photosensitive resin composition containing 10 parts by weight.

In the present invention, the weight average molecular weights of the alkali-soluble vinyl copolymer compounds (a) and (b) and the ratio of the copolymerization components are such that the glass transition point of the polymer, the water resistance and the developability of the composition. To the above range. The weight ratio of the alkali-soluble vinyl copolymer compound (a) and the vinyl copolymer compound (b), (a) / (b) is 10/90 to 90/10.
It is preferable to set it as the range.

By making the film-imparting polymer of the photosensitive resin composition into a two-component system, it is possible to obtain properties that cannot be obtained by a single component. That is, the vinyl copolymer compound (a)
When only one is used, a small peeling piece can be obtained, but the resist shape is poor, and in particular, a cavity is generated at the interface with the copper surface. When only the vinyl-based copolymer compound (b) is used, a good resist shape can be obtained, but the peeling pieces become large. By using the vinyl-based copolymer compound (a) and the vinyl-based copolymer compound (b) in combination, the peeling pieces are small, and the rolls of the automatic peeling machine are not entangled with the developing pieces, and there is no resist shape or void. You can get a vertical one without.

The monomer represented by the formula (I) is an ester of acrylic acid or an ester of methacrylic acid, for example, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic acid- 2-ethylhexyl, β-hydroxyethyl acrylate, lauryl acrylate, N, N′-acrylic acid
Dimethylaminoethyl, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, β-methacrylate
-Hydroxyethyl, 2-ethylhexyl methacrylate, lauryl methacrylate and the like.

As the ethylenically unsaturated compound used in the present invention, it is preferable to use an acrylate monomer or a methacrylate monomer from the viewpoint of high sensitivity. For example, polyethylene glycol diacrylate (the number of ethylene groups is 2
~ 14), polyethylene glycol dimethacrylate (the number of ethylene groups is 2-14), β-phenoxyethoxyethyl acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, 1,6-hexanediol diacrylate, 2, 2-bis (4-methacryloxyethoxyphenyl) propane, 2,2-bis (4-
Polyacrylates or polymethacrylates of polyhydric alcohols such as acryloxyethoxyphenyl) propane, dipentaerythritol pentaacrylate, trimethylolpropane trimethacrylate, adducts of trimethylpropane triglycidyl ether with acrylic acid or methacrylic acid, bisphenol A Alkylene glycol-based acrylates such as acrylic acid or methacrylic acid adducts, low molecular weight unsaturated polyesters such as phthalic anhydride-neopentyl glycol-acrylic acid 1: 1: 2 condensates, diisocyanates, dialcohols and hydroxy acrylates Examples thereof include urethane acrylates such as adducts, urethane isocyanates such as diisocyanates, dialcohols and adducts of hydroxymethacrylate. In particular, trifunctional or higher functional acrylates or methacrylates such as trimethylolpropane triacrylate are preferable for subdividing the strips.

The film-forming polymer (A) and the ethylenically unsaturated compound (B) are used in the above-mentioned weight ranges in an amount of 100 parts by weight in total. The film-forming polymer (A) and the ethylenically unsaturated compound (B) are used in the above weight range from the viewpoint of the resin flow property of the composition and the edge age.

The organic halogen compound is preferably one that easily releases a halogen radical by active light or one that easily releases a halogen radical by chain transfer.

Examples of organic halogen compounds are carbon tetrachloride, chloroform, bromoform, 1,1,1-trichloroethane, methylene bromide, methylene iodide, methylene chloride, carbon tetrabromide, iodoform, 1,1,2,2- Tetrabromoethane, pentabromoethane, tribromoacetophenone, bis-
(Tribromomethyl) sulfone, tribromomethylphenyl sulfone, vinyl chloride, chlorinated olefin, and the like. An aliphatic halogen compound having a weak carbon-halogen bond strength, particularly a compound in which two or more halogen atoms are bonded on the same carbon, particularly an organic bromine compound is preferable. An organohalogen compound having a tribromomethyl group gives more preferable results. The organic halogen compound is
It is used in the above weight range because it serves as an imaging agent or a radical source.

Further, there is no limitation on the sensitizer and the sensitizer system which can generate a free radical by the actinic ray in the present invention, and conventionally known ones can be used. For example, benzophenones such as benzophenone, 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone, 4,4′-dichlorobenzophenone, 2-ethylanthraquinone, t-butylanthraquinone, etc. Of anthraquinone, 2-chlorothioxanthone, benzoin ethyl ether, benzoin isopropyl ether, benzyl, 2,4,5-triarylimidazole dimer (lophin dimer), or two or more thereof are used.

From the viewpoint of the sensitivity of the photosensitive resin composition, the sensitizer and / or the sensitizer system capable of generating free radicals by actinic radiation are added in an amount of 0.5 to 10 parts by weight per 100 parts by weight of the film-forming polymer. Used.

There are no particular restrictions on the mixing order or mixing method of these materials.

In addition, a dye, a plasticizer, a pigment, a flame retardant, a stabilizer and the like can be added to the photosensitive resin composition of the present invention as required. It is also possible to use an adhesion promoter.

(Effects of the Invention) According to the present invention, it is possible to obtain a photosensitive resin composition which has a good resist shape and has fine pieces when peeled.

(Example) An example of the present invention will be described.

Example 1 A film-imparting polymer was synthesized by the following procedure.

1-a Production of vinyl copolymer compound (a) 120% of a mixture of methyl cellosolve / toluene at a weight ratio of 3/2 (hereinafter referred to as mixture A), methyl methacrylate 29.
8g, styrene 20g, ethyl acrylate 31.8g, methacrylic acid 4
Add g to a 500 ml flask and heat to 85 ° C. After incubating at 85 ℃ for 30 minutes, a solution prepared by dissolving 40 g of methyl methacrylate, 10.4 g of styrene, 14 g of ethyl acrylate, 50 g of methacrylic acid and 3.4 g of azobisisobutyronitrile in mixture A76 g was dropped into the flask for 4 hours and reacted. Let Then add 14g of mixture A 2
After keeping the temperature for a while, mix 0.1 g of azobisisobutyronitrile A2
Add a solution dissolved in 0 g and keep warm for 2 hours. Next, a solution of 0.02 g of hydroquinone in 10 g of mixture A was added and cooled to obtain a solution of vinyl copolymer compound (a).

1-b Production of vinyl copolymer compound (b) Mixture of methylcellosolve / toluene 3/2 by weight 97.
To 6 g (hereinafter referred to as the mixture B), 0.4 g of methacrylic acid, 2.6 g of methyl methacrylate, 0.3 g of n-butyl methacrylate and 3.1 g of 2-ethylhexyl acrylate were placed in a 500 ml flask and heated to 85 ° C. After incubating at 85 ℃ for 1 hour, 22.3g of methacrylic acid, 48.6g of methyl methacrylate, 17.3g of 2-ethylhexyl acrylate, 5.2g of n-butyl methacrylate, 0.17g of azobisisobutyronitrile were dissolved in 37.7g of mixture B. The resulting solution is dropped into the flask for 4 hours for reaction. Then add 9.0 g of methyl cellosolve, keep it warm for 2 hours, and then add methacrylic acid.
A mixture of 0.2 g and azobisisobutyronitrile 0.21 g B5.9 g
Add the solution dissolved in and keep it warm for another 5 hours.

Then 0.02 g of hydroquinone and 1.4 g of methyl cellosolve
A solution of the vinyl-based copolymer compound (b) was obtained by adding a solution of the above-mentioned solution and cooling.

The composition of the obtained vinyl copolymer compounds (a) and (b) is shown in Table 1, and the characteristics are shown in Table 2.

1-c Composition of photosensitive resin composition The following photosensitive resin compositions were compounded in the composition shown in Table 3 (V-1 and V-2 are shown as comparative examples).

1-d Manufacturing of photosensitive element and preparation of test piece V-
1 to V-5 photosensitive resin composition solution with a thickness of 23 μm
Polyethylene terephthalate film (Toray Industries, Inc.)
Made lumirror ) To a film thickness of 50 μm after drying.
Work-dried and covered with a polyethylene film with a thickness of 35 μm
To obtain a photosensitive element. Obtained photosensitive element
While peeling the polyethylene film from the photosensitive layer
The surface is Scott Bright Buffroll (Sumitomo Three M
Copper-clad laminate (100m)
(m × 200 mm) copper surface with Hitachi high temperature laminator
The test pieces were obtained by successively stacking. Table 4 shows the lamination conditions.

1-e Each test piece obtained in the characteristic 1-d of the photosensitive element was subjected to the following test, and the results are shown in Table 7.

(1) Sensitivity test A test piece obtained at 1-d was exposed at 80 mJ / cm ² with an ultra-high pressure mercury lamp through a negative having a 21-step step plate. After leaving for 30 minutes, peel off the polyethylene terephthalate film, develop with 1% sodium carbonate aqueous solution at 30 ° C,
The number of curing steps of the step plate was read.

(2) Peeling property The test piece obtained in 1-d was exposed in a 21-step stepper plate so as to have 8 steps, and then developed with a 1% sodium carbonate aqueous solution. Table 5 shows the developing conditions.

Then, the resist was peeled off with a 3% NaOH aqueous solution at 50 ° C., and the peeling piece size and the peeling end time (second) were measured. Table 6 shows the evaluation criteria for the size of the peeled pieces.

(3) Resist shape The test piece obtained in 1-d is exposed in a 21-step stepper plate so as to have 8 steps. After that, it was developed with a 1% sodium carbonate aqueous solution and the shape of the resist was observed by SEM (scanning electron microscope).

As is apparent from Table 7, the system in which the above-mentioned copolymerization compounds (a) and (b) are combined has smaller peeling pieces as compared with other systems and has a good resist shape.

Front page continued (72) Kenji Kamio 4-13-1 Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Plant (72) Inventor Kazutaka Masaoka 4-13-1 Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Plant (56) Reference JP 62-75633 (JP, A) JP 61-134756 (JP, A) JP 62-59946 (JP, A) JP 60-225841 (JP, A) JP-B-54-25957 (JP, B2)

Claims (3)

[Claims] 1. A) 20 to 40% by weight of methacrylic acid, 5 to 30% by weight of styrene, and 30 of the monomer represented by the general formula (I).
Weight average molecular weight obtained as a copolymerization component of ~ 75% by weight
A weight average of 10,000 to 50,000 alkali-soluble vinyl copolymer compound (a), 20 to 40% by weight of methacrylic acid and 60 to 80% by weight of the monomer represented by the general formula (I) as a copolymerization component. 40 to 80 parts by weight of a film-forming polymer containing an alkali-soluble vinyl copolymer compound (b) having a molecular weight of 60,000 to 150,000 (R ₁ means a hydrogen atom or a methyl group, R ₂ means an alkyl group having 1 to 12 carbon atoms) (B) 20 to 60 parts by weight of an ethylenically unsaturated compound (provided that (A) (The total amount of (B) is 100 parts by weight) (C) The total amount of organic halogen compounds (A) and (B) is 100.
0.2 to 10 parts by weight with respect to parts by weight (D) A sensitizer and / or a sensitizer system capable of generating free radicals by actinic rays is 0.5 to 100 parts by weight with respect to 100 parts by weight of the total of (A) and (B). A photosensitive resin composition containing 10 parts by weight. 2. The weight ratio (a) / (b) of the vinyl copolymer compound (a) and the vinyl copolymer compound (b) is 10/90 to 90 /.
The photosensitive resin composition according to claim 1, which is 10. 3. The organic halogen compound is an organic halogen compound having a tribromomethyl group.
Item or the photosensitive resin composition according to Item 2.