JPH04157467A - Photosensitive resin composition and photosensitive resin composition laminate using the same - Google Patents

Abstract

PURPOSE:To obtain a print wiring plate that is improved in flexibility and separatability and has an excellent tenting quality, by containing a film quality polymer, a specific compound, a compound containing ethylene unsaturated groups, a photopolymerization start agent and polyalkylene glycol. CONSTITUTION:A film quality polymer containing a carboxyl group, a compound shown in a formula I, a compound containing at least two ethylene unsaturated groups, a photopolymerization initiator and polyalkylene glycol are contained. As for the formula I, Z represents a cyclic dibasic acid residual radical, and R1 represents an alkylene group of carbon atom number 1-6, and R2 represents hydrogen or a methyl group, and Y represents hydrogen and an alkyl group of carbon atom number 1-4 or -CH2-X (X is chlorine or bromine.). As a result, a high quality print wiring board that is excellent in flexibility and separatability and also superior in a tenting quality, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive resin composition and a photosensitive resin composition laminate using the same.

[Conventional technology]

In the field of manufacturing printed wiring boards, photosensitive resin compositions and photosensitive resin composition laminates (hereinafter referred to as photosensitive films) are widely used as resist materials used in methods such as etching and plating.

As photosensitive resin compositions, both an alkali-developable type in which unexposed areas are removed (developed) with an alkaline aqueous solution and a solvent-developable type in which the unexposed areas are removed by an organic solvent are known.

When using a photosensitive laminate using an alkali-developable resin composition, first remove the protective film from the photosensitive laminate and use a printed wiring board substrate (hereinafter referred to as The photosensitive layer is heat-pressed (80 to 160°C,
2-4 kg/cd) and laminate. The substrate consists of a metal foil laminated on an insulating layer, and is pre-treated by polishing to remove moisture. Next, after imagewise exposure is performed using a negative film or the like, unexposed areas are removed (developed) using an alkaline aqueous solution to form a photoresist image. Furthermore, a printed wiring board is manufactured by etching or plating a metal foil using the formed photoresist image as a mask, and then peeling off the photoresist image using a developer and a strongly alkaline aqueous solution.

In recent years, in the field of printed wiring boards, there has been a demand for flexible wiring materials as electrical circuit materials for cameras, automobiles, etc., and flexibility after curing is also strongly desired for photosensitive films for forming these circuits. .

In addition, a spray of sodium hydroxide aqueous solution is used to remove alkaline-developable resin compositions, and this sodium hydroxide causes problems such as discoloration of the copper surface and burnt solder. A sex film is desired. Addition of a plasticizer and combination of monofunctional monomers and polyfunctional monomers are important for creating photosensitive resin compositions with fast flexibility and peeling time. The strength of the resin film decreases, and the ability to protect through holes present in printed circuit boards (tenting properties) decreases. Therefore, selection of these plasticizers and monofunctional monomers is important.

[Problem to be solved by the invention]

The purpose of the present invention is to improve the above-mentioned flexibility and peelability,
Another object of the present invention is to provide an alkali-developable photosensitive resin composition with good tenting properties and a photosensitive resin composition laminate using the same.

[Means to solve the problem]

The present invention includes (A) a carboxyl group-containing film-like polymer (B)
- Formula (I) [In the formula, Z represents a cyclic dibasic acid residue, R1 represents an alkylene group having 1 to 6 carbon atoms, R3 represents hydrogen or a methyl group, and Y represents hydrogen or a carbon atom Represents an alkyl group of numbers 1 to 4 or -CH, -X (X is chlorine or bromine)]
A photosensitive resin composition comprising a compound represented by (C) a compound containing a small number (both of which contain two ethylenically unsaturated groups), (D) a photopolymerization initiator, and (E) a polyalkylene glycol; The present invention relates to a photosensitive resin composition laminate using the composition.

The carboxyl group-containing film-forming polymer used in the present invention as component (A) is a polymer that can be dissolved or swelled in an alkaline developer, such as methacrylic acid, acrylic acid, fumaric acid monovinyl ester, maleic acid, etc. Monomers having a carboxyl group and an unsaturated group such as monovinyl ester, monovinyl itaconate, and monovinyl maleate, and methyl methacrylate;
Alkyl esters of acrylic acid or methacrylic acid such as methyl acrylate, ethyl methacrylate, ethyl acrylate, butyl methacrylate, butyl acrylate, 2-ethylhexyl methacrylate, 2-ethylhexyl acrylate, styrene, vinyltoluene, acrylamide, methacryl A copolymer with a monomer such as amide is used.

The usage amount of the monomer having a carboxyl group and an unsaturated group is 15 to 85% from the viewpoint of imparting alkaline developability.
It is preferable to set it as mol%. This usage amount is 15 mol%
If it is less than 35 mol %, the developability tends to deteriorate, and if it exceeds 35 mol %, the developer resistance of the cured part tends to decrease. (A) The molecular weight of the film property imparting polymer is preferably in the range of so, ooo to soo, ooo in terms of weight average molecular weight. If the molecular weight is too small, film properties and film strength will tend to deteriorate, and if the molecular weight is too large, developability will tend to deteriorate.

The blending amount of (A) the carboxyl group-containing film property-imparting polymer is the sum of (A) the film property-imparting polymer, (B) the compound represented by general formula (I), and (C) the compound containing an ethylenically unsaturated group. [(A)+(B)+(C))
is defined as 100 parts by weight (hereinafter referred to as "parts by weight", this definition applies), preferably 30 to 80 parts by weight, more preferably 40 to 70 parts by weight. Also, (A)
Two or more types of component film-imparting polymers may be used.

The compound represented by the general formula (I), which is the component (B), can be produced, for example, by the method disclosed in Japanese Patent Publication No. 61-25736. That is, it is easily produced by reaction with a cyclic dibasic acid anhydride according to the following formula.

/ 1 + Z \ -OH \ -OH / -> Z \ [wherein R1, R1, Z and Y are the same as defined in formula (I)].

R1 represents an alkylene group having 1 to 6 carbon atoms, but if the number of carbon atoms is 7 or more, it becomes difficult to synthesize the compound and the alkali developability deteriorates.

Examples of the alkyl group having 1 to 4 carbon atoms of Y include methyl group, ethyl group, propyl group, isopropyl group, butyl group,
Examples include 5ee-butyl group and tert-butyl group.

When the number of carbon atoms is 5 or more, it becomes difficult to synthesize the compound and the alkali developability deteriorates.

Examples of the cyclic dibasic acid anhydride include succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride.

(B) Among the compounds represented by general formula (I), general formula (
1) Those in which Y is -CHs, -CH, or CI are preferred from the viewpoint of tenting properties.

(B) The compounding amount of the compound represented by general formula (I) is 5 to 5.
85 parts by weight is preferred. If this amount is less than 5 parts by weight, it tends to be less effective in shortening the peeling time and improving flexibility, and if it exceeds 35 parts by weight, the curing rate tends to decrease. The amount is not uniquely determined, but depends on the type and amount of the compound (both containing two or more ethylenically unsaturated groups) to be mixed and the type and amount of polyalkylene glycol.
Determined from the properties of tenting and flexibility.

Examples of the compound containing at least two ethylenically unsaturated groups, which is component (C), include polyhydric alcohols containing α,
Those obtained by adding β-unsaturated carboxylic acid, for example, tetraethylene glycol di(meth)acrylate [(meth)acrylate means acrylate or methacrylate. The same applies hereinafter), polyallene glycol di(meth)acrylate (the number of ethylene groups is 2 to 14),
trimethylolbroban di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate, polyalkylene glycol di(meth)acrylate( (having 2 to 14 propylene groups), dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 2,2-bis(4-((meth)acryloxy-jethoxy)phenyl]propane , 2,2-bis[4-((meth)acryloxy-polyethoxy)phenyl]propane, etc. Component (C) preferably has a boiling point of 150° C. or higher at room temperature.

Examples of the photopolymerization initiator as component (D) include benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N,N-tetramethyl-4,4'-diamino Benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-
Aromatic ketones such as ethyl anthraquinone and phenanthrenequinone, benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether, benzoins such as methylbenzoin and ethylbenzoin, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(0-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5
-diphenylimidazole dimer, 2-(o-methoxyphenyl)=4.5-diphenylimidazole dimer,
2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer, 2-(2,4-
dimethoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methylmercaptophenyl)-4
, 2.4.5-1 of 5-diphenylimidazole dimer
Really imidazole dimers and the like can be used alone or in combination. (D) The amount of photopolymerization initiator is 0.1
~15 parts by weight is preferred. If the amount is less than 0.1 part by weight, photosensitivity tends to decrease, and if it exceeds 15 parts by weight, absorption of light on the surface of the composition increases during exposure, and the internal tends to have insufficient optical hardness.

Examples of the polyalkylene glycol of component (E) include polypropylene glycol, polyethylene glycol, polybutylene glycol, block copolymers of polypropylene glycol and polyethylene glycol, and monoalkyl esters of these polyalkylene glycols. (E) The weight average molecular weight of the polyalkylene glycol is preferably 300 to io, ooo.

(E) The blending amount of polyalkylene glycol is preferably 1 to 10 parts by weight. If it is less than 1 part by weight, the effect on flexibility tends to be small, and if it exceeds 10 parts by weight, tenting properties tend to decrease.

Generally, in order to prevent thermal polymerization during the heating process and during storage, it is preferable that the photosensitive layer contains a radical polymerization inhibitor. Examples of such radical polymerization inhibitors include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, phenothiazine, pyridine, nitrobenzene, dinitrobenzene, p-toluquinone, chloranil, and arylphosphite, but at temperatures below 200°C. are preferred, such as alkyl-substituted hydroquinone, tert-butylcatechol, cuprous chloride, 2,6-
C-tert-butyl p-cresol, 2,2-methylenebis(4-ethyl-6-t-butylphenol), 2
．． Examples include 2-methylenebis(2-methyl-6-t-butylphenol).

The photosensitive resin composition described above may contain coloring substances such as dyes and pigments. The colored substance is preferably one that does not affect the properties of the photoresist and does not decompose or volatilize at temperatures below 200°C. Colorants that can be used include, for example, Tsukusin, Auramine Base, Calcocyto Green S, Paramazienta, Crystal Violet, Methyl Orange, Dill Blue 2B, Victoria Blue, Malachite Green, and Paysic Blue 20.
, Eye Orange Green, Night Green B, Tripalosan, New Marienta, Acid Violet RRH
, Red Violet 5R3, New Methylene Blue G
There are G, etc.

When laminating the photosensitive resin composition on a support, a solvent may be added to the photosensitive resin composition. The solvent is not particularly limited as long as it dissolves the photosensitive resin composition, and one or more solvents may be used. Examples of the solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, dichloromethane, chloroform, methyl alcohol,
Ethyl alcohol etc. are used. This photosensitive resin composition may be directly applied to the substrate by known means such as a roll coater, curtain coater, or various printing methods, or may be applied to a photosensitive resin composition laminate, that is, a photosensitive film. Alternatively, it may be used by first applying it to a support such as a film, drying the solvent, and then laminating the layers. The thickness of the photosensitive layer is a normal thickness, preferably 10 to 100 μm, and 20 to 60 μm.
m is more preferred.

A photosensitive film consisting of two layers, a photosensitive layer and a film-like support, is stored as it is or after a protective film is further laminated on the other side of the photosensitive layer and the film is wound up into a roll.

Examples of the film-like support include films of polyethylene terephthalate, polypropylene, polyethylene, etc., with polyethylene terephthalate film being preferred. The thickness of this film is preferably 5 to 100 μm, more preferably 10 to 30 μm.

Moreover, the above-mentioned film can be used as a protective film, and a polyethylene film is preferable.

When producing a photoresist image, if the protective film is present, it is removed and then the photosensitive layer is laminated by pressing the photosensitive layer against the substrate while heating. Although there are no particular restrictions on the surface to be laminated, heating of the substrate is not necessary depending on the temperature at which the photosensitive layer is heated (laminating temperature), but heating may be performed to further improve lamination properties.

The laminated photosensitive layer is then imagewise exposed to actinic light using a negative or positive film. At this time, if the polymer film present on the photosensitive layer is transparent, it may be exposed as is; if it is opaque,
Of course it needs to be removed. In order to protect the photosensitive layer, it is preferable that the polymer film is transparent and that the polymer film is exposed through it while remaining. Examples of active rays include carbon arc, mercury vapor arc,
Light generated from an active light source such as a xenon arc is used. Since the sensitivity of the photopolymerization initiator contained in the photosensitive layer is usually maximum in the ultraviolet region, the active light source should be one that effectively emits ultraviolet light. For example, in the case of 9,10-phenanthrenequinone, visible light is used as the active light, and in addition to the above-mentioned light sources, a photographic flood light bulb, a solar lamp, etc. can also be used as the light source. After exposure, if a film-like support is present on the photosensitive layer, it is removed and then removed by a known method such as spraying, shaking dipping, brushing, or scraping using an alkaline aqueous solution. The exposed area is removed and developed. The base of the alkaline aqueous solution used at this time includes, for example, alkali hydroxide such as hydroxide of lithium, sodium or potassium, alkali carbonate such as carbonate or bicarbonate of lithium, sodium or potassium, potassium phosphate or phosphorus. Examples include alkali metal phosphates such as sodium acid, alkali birophosphates such as sodium pyrophosphate and potassium birophosphate, and particularly preferred is an aqueous solution of sodium carbonate. For development, it is preferable to use an alkaline aqueous solution of 0.5 to 3% by weight, and the pH thereof is preferably 9 to 12.

Further, the development temperature can be adjusted depending on the developability of the photosensitive layer.

Furthermore, a surfactant, an antifoaming agent, or a small amount of an organic solvent for accelerating development can be mixed into the alkaline aqueous solution.

Further, in manufacturing printed wiring boards, the exposed surface of the substrate is treated by conventional etching or plating methods using the developed photoresist image as a mask. The photoresist image is then stripped with an aqueous solution that is more strongly alkaline than the alkaline aqueous solution normally used for development. As the strongly alkaline aqueous solution, for example, 2 to 10% by weight of sodium hydroxide is used.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Examples 1 to 4 and Comparative Examples 1 to 4 40% by weight ethyl cellosolve solution of methyl methacrylate/ethyl acrylate/methacrylic acid copolymer (weight ratio 60/20/20, weight average molecular weight 100,000)
150g Michler's Ketone
0.2 g benzophenone
5-0g Victoria Pure Blue
o, o s g leuco crystal violet
1.0g tribromomethylphenylsulfone 0.
Solution A was obtained by blending 21.17 g of 6 gp-toluenesulfonamide zog methyl ethyl ketone.

Next, each component *12. was added to this solution A in the proportions shown in Table 1.
Trade name of 2-bis[4-(methacryloxy-polyethoxy)phenylene]propane (manufactured by Shin Nakamura Chemical Co., Ltd.) *2 A compound synthesized from phthalic anhydride, 2-hydroxyethyl methacrylate, and epichlorohydrin] *8 Phthalic anhydride and 2 -Made from hydroxyethyl methacrylate and propylene glycol *4 Trade name of phenoxypolyethylene glycol acrylate (manufactured by Shin Nakamura Chemical) *5 Polypropylene glycol (weight average molecular weight 2
000, trade name, manufactured by Asahi Denka ■) *6 Ethylene oxide-propylene oxide copolymer (weight average molecular weight 2000, trade name, manufactured by Dow Chemical ■) Photosensitive resins of Examples 1 to 4 and Comparative Examples 1 to 4 Each of the solutions of the assembled materials was laminated on a support using the coating apparatus shown in FIG. As shown in FIG.
It is coated on a polyethylene terephthalate film (East Lumirror) 2 having a film thickness of 30 μm after drying, dried in a dryer 3, and fed out from a polyethylene film feed roll 10 to a thickness of 85 μm.
The photosensitive film obtained by being coated with a .mu.m polyethylene film 4 is wound onto a photosensitive film winding roll 13. In addition, in Figure 1, 6.7.8.1
1 and 12 are rolls, and 9 is a knife.

While peeling off the polyethylene film from the obtained photosensitive film, the photosensitive layer surface was polished with Scotchflite 0 Buff Roll (manufactured by Jujum Three M), dried, and washed on the copper surface of a copper-clad laminate (100 m + x 200 mm). A test piece was obtained by continuously laminating layers using a high-temperature laminator manufactured by Hitachi.

The lamination conditions at this time are shown in Table 2.

Table 2 (note) *Air cylinder pressure The following tests were conducted on each of the test pieces thus obtained.

(a) Sensitivity test The specimen was exposed to light at 100 mJ/cm using an ultra-high pressure mercury lamp through a negative equipped with a 21-step step tablet. 3
After standing for 0 minutes, the polyethylene terephthalate film was peeled off, developed with a 1% by weight aqueous sodium carbonate solution, and the number of remaining steps on the step tablet was read. Examples 1-4
, Comparative Examples 1 to 4 showed almost the same sensitivity, and the number of remaining plates was approximately 8.

(b) Peeling time test The specimen was exposed to light in 8 steps of 21 steps, and then developed at 30° C. using a 1% by weight aqueous sodium carbonate solution. After development, the film was peeled off at 50° C. using an 8% by weight aqueous sodium hydroxide solution, and the time until the peeling was completed was measured. The results are shown in Table 3.

(d) Adhesion The test piece was exposed to light in 21 steps to form 8 steps, and then developed at 30° C. using a 1% by weight aqueous sodium carbonate solution. After development, etching was performed with a cupric chloride solution at 50° C., and then four diagonal goblets were made with a knife and peeled off with tape, and the peeling state of the resist was evaluated. The results are shown in Table 8.

○, △ and × in the table have the following meanings.

○: No peeling △ Partial peeling ×: Peeling on the entire surface (e) Tenting property A copper-clad laminate with a through-hole hole of 8 cm in diameter was polished with Scotchbride [F] Buff Roll (manufactured by Jubiru Three M). After drying and washing, each photosensitive film was laminated on both sides while removing the polyethylene film under the lamination conditions shown in Table 2.

This substrate was exposed to light in 8 stages using a 21-stage step tablet, and then developed at 30°C for 60 seconds using a 1% by weight aqueous sodium carbonate solution. After development, etching was performed for 120 seconds using a cupric chloride solution at 50° C. at a spray pressure of 2 kg/cd, and tent tearing was observed and evaluated using the following criteria.

○: No tears △: Tears in 9 holes or less out of 330 holes It is superior in releasability, adhesion and tenting properties.

〔Effect of the invention〕

The photosensitive resin composition of the present invention and the photosensitive resin composition laminate using the same have extremely good flexibility and peelability,
Moreover, it has excellent tenting properties, and as a result, a high-quality printed wiring board can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a photosensitive film manufacturing apparatus used in Examples. Explanation of symbols 1... Solution of photosensitive resin composition, 2... Polyethylene terephthalate film, 3... Dryer, 4...
Polyethylene film, 5...Feeding roll, 10
...Polyethylene film feed roll, 18...
・Photosensitive film winding roll FIG. 1 1...Photosensitive resin composition 2...Polyethylene terephthalate film 3...
Dryer 4...Polyethylene film 5...Feeding roll

Claims (4)

[Claims] 1. (A) Carboxyl group-containing film properties imparting polymer (B) General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [In the formula, Z represents a cyclic dibasic acid residue, and R_1 has a carbon atom number of 1 ~6 alkylene group, R_2 represents hydrogen or a methyl group, Y represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or -CH_2-X (X is chlorine or bromine)] A photosensitive resin composition comprising: (C) a compound containing at least two ethylenically unsaturated groups; (D) a photopolymerization initiator; and (E) polyalkylene glycol. 2. Carboxyl group-containing film properties imparting polymer (A)
For a total of 100 parts by weight of the compound (B) represented by general formula (I) and the compound (C) containing at least two ethylenically unsaturated groups, carboxyl group-containing film properties imparting polymer (A) is added. 30-80 parts by weight, formula (I)
The photosensitive resin composition according to claim 1, comprising 5 to 35 parts by weight of the compound (B) and 1 to 10 parts by weight of the polyalkylene glycol (E). 3. A photosensitive resin composition laminate comprising the photosensitive resin composition according to claim 1 laminated on a support. 4. The photosensitive resin composition laminate according to claim 3, wherein the photosensitive layer has a thickness of 10 to 100 μm.