JP2570758B2 - Photosensitive resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a photosensitive resin composition, and more particularly to a novel photosensitive resin composition having increased photosensitivity.

[Conventional technology]

In the fields of manufacturing printed wiring boards, precision metal processing, etc., a photosensitive resin composition and a photosensitive resin composition obtained using the same as a resist material used for chemical and electrical methods such as etching and plating. Laminate (hereinafter, referred to as
Photosensitive film) is widely used.

Methods for manufacturing a printed wiring board include a tenting method and a plating method. Among these, the plating method means that a photosensitive resin composition laminated or coated and dried on a copper-clad laminate is irradiated with light using a negative-type photomask, and after the exposed portion is developed, This is a method in which metal plating such as plating, nickel plating, gold plating, solder plating, and tin plating is performed, the cured photosensitive resin composition is peeled off, and copper is etched to obtain a desired circuit. When used as a permanent mask, it is further cured by light or heat.

Increasing the photosensitivity of the photosensitive resin composition,
This is advantageous in that the exposure time of the active light can be shortened, and intensive studies have been made in the past. For example, JP-A-47-
No. 4126 discloses a photosensitive resin composition containing an acridine-type or phenazine-type compound as a photopolymerizable initiator, and among the compounds having high photosensitivity, 9-
Phenylacridine, 9-p-tolylacridine, 9-
Acetylaminoacridine and the like are mentioned. However, when solder plating is performed using a photosensitive resin composition containing these compounds, the solder dissolves after etching,
There is a problem that a thin portion of the line is seen and a precise circuit cannot be formed.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel photosensitive resin composition which eliminates the drawbacks of the above-mentioned prior art and has an increased photosensitivity without dissolving solder after etching.

[Means for solving the problem]

The present invention relates to (a) a polymer having a weight average molecular weight of at least 320;
And the general formula (I) (Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen, halogen, an alkyl group or a methoxy group having 1 to 8 carbon atoms, and X is acrylidyl A substituted or unsubstituted aromatic ring conjugated to a group), a photopolymerization initiator having an acrylidyl side group, (b) a thermoplastic organic polymer compound, and (c) a light having at least one terminal ethylene group. The present invention relates to a photosensitive resin composition containing a polymerizable compound.

The photopolymerization initiator (a) in the present invention is a compound having a weight average molecular weight of 320 or more and further having an acrylidyl side group having an aromatic ring conjugated to the acrylidyl group of the general formula (I) in one molecule. From the viewpoint of the sensitivity of the photosensitive resin composition obtained from these compounds, the compounds represented by the general formula (II) [Wherein, Z ₁ is a phenylene group or a 6-membered heterocyclic aromatic group, R ₉ is a substituted or unsubstituted alkyl group having 9 to 15 carbon atoms, an aryl group, an alkoxy group, a general formula (—O—CO 2 −NH
−R ₁₀ ), general formula Or the general formula (-O-CONH-Y-NHCOO -R 12).
However, R ₁₀ is a substituted or unsubstituted alkyl group having 4 to 20 carbon atoms, a substituted or unsubstituted alicyclic group or substituted or unsubstituted aryl group having 4 to 20 carbon atoms, and R ₁₁ is a hydrogen or methyl group. , Y is a substituted or unsubstituted alkyl group or a substituted or unsubstituted alicyclic group, R ₁₂ is a substituted or unsubstituted alkyl group or a formula (Where R ₁₃ is hydrogen or a methyl group, R ₁₄ is an acryl group,
(Methacrylic group or alkyl group). And specifically, a compound obtained by reacting pn-hexylbenzoic acid with diphenylamine in the presence of polyphosphoric acid, and a reaction product of p-2-ethylhexylbenzoic acid with diphenylamine A reaction product of 9- (p-hydroxylphenyl) acridine with octadecyl isocyanate, hexyl diisocyanate or 2,4,4-trimethylhexyl diisocyanate; Reaction of p-9-acrylidylbenzoic acid obtained by oxidizing p-tolylphenylacridine with a reaction product of diethylene glycol monoethyl ether or monoacryl polyethylene glycol, or a polymer or oligomer having a hydroxyl group with p-9-acrylidylbenzoic acid Compound,
A reaction product of 9- (p-hydroxyphenyl) acridine, diisocyanate and monoacrylalkylene glycol is exemplified.

When the weight average molecular weight of these compounds is less than 320, problems such as dissolution of solder and an increase in the amount of dissolution in a plating solution occur. In addition, the content of the acrylidyl side group is preferably 1% by weight or more based on the weight average molecular weight of the photopolymerization initiator from the viewpoint of sensitivity and resolution of the photosensitive resin composition. The amount of the photopolymerization initiator (a) used is 0.5 parts by weight to 70 parts by weight based on 100 parts by weight of the components (a), (b) and (c) in view of the sensitivity of the obtained photosensitive resin composition. Is preferable. A more preferred amount is such that the coated and dried photosensitive resin composition has an ultraviolet wavelength or an absorbance of 365 nm light of 0.3.
It is an amount that becomes ~ 3.0.

Further, as the photopolymerization initiator in the invention, one or more other known photopolymerization initiators can be used in combination.

The thermoplastic organic high molecular compound (b) in the present invention is not particularly limited as long as it is a film-providing polymer, but the photosensitive resin composition obtained by using these compounds has a high solubility in each developer. It is preferably a molecular weight. For example, a solvent-developing type is a methacrylic acid copolymer of a vinyl copolymer having a weight average molecular weight of 20,000 to 400,000, and an alkali developing type is a carboxyl group content of 17 to 50 mol% and a weight-average molecular weight of 3 to 3. Preferred are ~ 400,000 linear copolymers and the like. Examples of the vinyl polymerizable monomer used in the vinyl copolymer include methyl methacrylate, butyl methacrylate, α-ethylhexyl methacrylate, lauryl methacrylate, ethyl acrylate, methyl styrene acrylate, vinyl toluene, and N-vinyl. Pyrrolidone, α-methylstyrene, α-hydroxyethyl methacrylate, 2
-Hydroxyethyl acrylate, acrylamide, acrylonitrile, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate and the like. As monomers used for the linear copolymer having a carboxyl group, acrylic acid, methacrylic acid, fumaric acid,
Cinnamic acid, itaconic acid, maleic acid and the like.

The amount of the thermoplastic organic polymer compound (b) to be used is 30 parts by weight based on 100 parts by weight of the components (a), (b) and (c) in view of the flexibility of the obtained photosensitive resin composition.
A range of -80 parts by weight is preferred.

The photopolymerizable compound (c) having at least one terminal ethylene group in the present invention may be any addition polymerizable substance having at least one terminal ethylenically unsaturated group, such as trimethylolpropane triacrylate,
Pentaerythritol triacrylate, 1,6-hexanediol diacrylate, 2,2-bis (4-methacryloxyethoxyphenyl) propane, 2,2-bis (4-
(Acryloxyethoxyphenyl) propane, dipentaerythritol pentaacrylate, polyacrylate or polymethacrylate of trimethylolpropane trimethacrylate, adduct of trimethylpropane triglycidyl ether with acrylic acid or methacrylic acid, bisphenol A epichlorohydrin Epoxy acrylates such as acrylic acid or methacrylic acid adducts of epoxy resins; low molecular unsaturated polyesters such as condensates of phthalic anhydride-neopentyl glycol-acrylic acid in a ratio of 1: 1: 2 (molar ratio); trimethylhexamethylene Urethane diacrylate compounds obtained by reacting diisocyanates, monoesters of acrylic acid or methacrylic acid of dihydric alcohols, 2,2,2 ', 2'-
An ester compound of acrylic acid with a condensate of tetrakis (hydroxylmethyl) -3,3'-oxydipropanol and an adduct of 6-hexanolide is used.

The amount of the photopolymerizable compound (c) to be used depends on the above (a) and (b) in view of the flexibility of the obtained photosensitive resin composition.
The amount is preferably in the range of 10 to 70 parts by weight based on 100 parts by weight of component (c).

Incidentally, the photosensitive resin composition of the present invention, a known dye,
A plasticizer, a chain transfer agent, a pigment, a flame retardant, a stabilizer, an adhesion-imparting agent, and the like can be added as necessary.

The photosensitive resin composition of the present invention is formed into a solution using an organic solvent such as methyl ethyl ketone, methyl cellosolve, and methylene chloride, and is coated on a processing object in a solution state.
It is used after being dried or coated on a film-like support and used as a photosensitive film. As the film support, a polyethylene terephthalate film, a polystyrene film, a polypropylene film, or the like is used. If necessary, on the photosensitive film,
A protective film may be laminated. As the protective film, a polyethylene film, a polyvinyl alcohol film and the like are used in addition to the above-mentioned materials used as the film-like support.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

Example 1 (Synthesis of photopolymerization initiator SI) 273 g (1.62 mol) of diphenylamine, 167 g (0.81 mol) of pn-hexylbenzoic acid and 1400 g of polyphosphoric acid were mixed, and the mixture was stirred at 220 ° C. for 8 hours under a nitrogen gas stream. Stirred. After cooling, the mixture was poured onto ice and water 8 was added. Take the water layer,
After filtering off the insoluble matter, a 50% by weight aqueous solution of potassium hydroxide was added to obtain PH12. The resulting oil was extracted with chloroform 2, washed thoroughly with water, and dried using anhydrous sodium sulfate. The column was collected with chloroform, and after distilling, a product was obtained. The product had an ultraviolet absorption spectrum of 357 nm.
Was confirmed to be 9- (pn-hexylphenyl) acridine (hereinafter, referred to as S-1). The molecular weight was 326.

(Production of photosensitive film) A photosensitive resin composition was prepared using the obtained photopolymerization initiator SI in accordance with the compounding ratio shown in Table 1. Next, a photosensitive film was produced from the photosensitive resin composition using the coating apparatus shown in FIG. That is, in FIG.
The photosensitive resin composition solution 6 has a thickness of 25 μm drawn from the polyethylene terephthalate film pay-out roll 1.
m roll on polyethylene terephthalate film
The coating is uniformly applied by 2, 3, and 4, and dried by a hot air convection dryer 7 at 100 ° C. for 3 minutes to remove the solvent, thereby forming a photosensitive layer having a thickness of about 50 μm. 5 is a knife. The photosensitive film having the photosensitive layer is bonded to the protective film drawn out of the polyethylene film pay-out roll 8 by rolls 9 and 10 and wound up by a photosensitive film take-up roll 11.

The measurement of the photosensitivity and the plating test of the thus obtained photosensitive film were performed by the following test methods. The results are shown in Table 2.

<Test Method> The protective film of the photosensitive resin film produced on a copper-clad laminate of 200 mm × 250 mm was peeled off and laminated while pressing with a 110 ° C. hot roll. The following test was performed on the obtained substrate.

(1) Measurement of photosensitivity Using a Kodak 21-step tablet, 3KW
Exposure with a high-pressure mercury lamp for 20 seconds, development with a 1% by weight sodium carbonate solution at 30 ° C for 75 seconds, and the number of remaining steps (ST)
Was observed. The higher the number of STs, the higher the sensitivity.

(2) Plating test Using an IPC pattern negative, exposure was performed for an exposure time of ST = 8, development was performed, and a plating-etching step shown in Table 3 was performed. Next, the surface after the etching was observed using a 100 × magnification projector, and the dissolution of the solder was examined.

Example 2 (Synthesis of photopolymerization initiator S-II) 9- (p-hydroxylphenyl) acridine 2.7 g
(0.01 mol) was dissolved in 200 ml of pyridine, 2 g (0.02 mol) of isophorone diisocyanate was added, and the mixture was heated to 50 ° C. and stirred for 8 hours. Thereafter, 6 g (0.015 g) of monoacryl polypropylene glycol having a weight average molecular weight of about 400 (registered trademark Nissan Blemmer PP-1000, manufactured by NOF CORPORATION)
Mol) and stirred for an additional 4 hours. The reaction product was poured into n-hexane (2), the hexane-soluble portion was taken out, and hexane was distilled off to obtain a reaction product. The ultraviolet absorption spectrum of the produced product had an absorption maximum at 358 nm, and it was confirmed that the product was the target product having an acrylidyl side group (hereinafter, referred to as S-II). The weight average molecular weight was about 1,100 (styrene equivalent molecular weight). 9 by thin layer chromatography
It was confirmed that there was no-(P-hydroxyphenyl) acridine.

(Production of Photosensitive Film) Using the obtained photopolymerization initiator S-II, a photosensitive resin composition was adjusted according to the compounding ratio shown in Table 1, and a photosensitive film was produced in the same manner as in Example 1. The measurement of the photosensitivity and the plating test were performed in the same manner as in Example 1.
The results are shown in Table 2.

Comparative Examples 1 to 3 9-phenylacridine (Comparative Example 1), 9- (p-hydroxylphenyl) acridine (Comparative Example 2), diethylaminobenzophenone and benzophenone (Comparative Example 3) were used as photopolymerization initiators, respectively. The photosensitive resin composition was adjusted according to the mixing ratio shown in Table 1, and a photosensitive film was produced in the same manner as in Example 1.
The light sensitivity measurement and the plating test were performed in the same manner as described above. The results are shown in Table 2.

From the results shown in Table 2, it is shown that the examples have high light sensitivity, do not show solder melting, and are practical.

〔The invention's effect〕

Since the photosensitive resin composition of the present invention has high photosensitivity and does not dissolve solder after etching, precise circuit formation is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an apparatus for applying a photosensitive resin composition. 1 ... Polyethylene terephthalate film feeding roll, 2, 3, 4, 9, 10 ... Roll, 5 ... Knife,
6 ... photosensitive resin composition solution, 7 ... dryer, 8 ... polyethylene film pay-out roll, 11 ... photosensitive film take-up roll.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yumiko Tanaka 4-13-1, Higashicho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Chemical Co., Ltd. Yamazaki Factory (56) References JP-A-63-256602 (JP, A)

Claims (2)

(57) [Claims] (A) a weight average molecular weight of at least 320;
And the general formula (I) (Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen, halogen, an alkyl group or a methoxy group having 1 to 8 carbon atoms, and X is acrylidyl A substituted or unsubstituted aromatic ring conjugated to a group), a photopolymerization initiator having an acrylidyl side group, (b) a thermoplastic organic polymer compound, and (c) a light having at least one terminal ethylene group. A photosensitive resin composition containing a polymerizable compound. 2. The photopolymerization initiator of the general formula (II) [Wherein, Z ₁ is a phenylene group or a 6-membered heterocyclic aromatic group, R ₉ is a substituted or unsubstituted alkyl group having 9 to 15 carbon atoms, an aryl group, an alkoxy group, a general formula (—O—CO 2 −NH
−R ₁₀ ), general formula Or the general formula (-O-CONH-Y-NHCOO -R 12).
However, R ₁₀ is a substituted or unsubstituted alkyl group having 4 to 20 carbon atoms, a substituted or unsubstituted alicyclic group or substituted or unsubstituted aryl group having 4 to 20 carbon atoms, and R ₁₁ is a hydrogen or methyl group. , Y is a substituted or unsubstituted alkyl group or a substituted or unsubstituted alicyclic group, R ₁₂ is a substituted or unsubstituted alkyl group or a formula (Where R ₁₃ is hydrogen or a methyl group, R ₁₄ is an acryl group,
(Methacrylic group or alkyl group). The photosensitive resin composition according to claim 1, which is represented by the following formula: