JPH07128851A - Photosensitive resin composition and photosensitive element using the same - Google Patents

Abstract

PURPOSE:To obtain a photosensitive resin compsn. excellent in plating resistance and adhesion to a substrate metal by using a photopolymerizable compd. having a polymerizable ethylenically unsatd. group in each molecule as a component and incorporating specified compds. into the component. CONSTITUTION:A polymer (A) having carboxyl groups as a binder, a photopolymn. initiator (B) and a photopolymerizable compd. (C) having at least one polymerizable ethylenically unsatd. group in each molecule are used as components and a compd. represented by formula I and a compd. represented by formula II are incorporated as essential components into the component C. In formula I, R is H or alkyl, (m) is an integer of 1-20 and X is-(CH2)n-[(n) is an integer of 1-20], etc. The content of the unsatd. urethane compd. [urethane (meth)acrylate] represented by formula I in the component C is preferably regulated to 10-90 pts.wt. per 100 pts.wt. of the component C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a photosensitive resin composition and a photosensitive element using the same.

[0002]

2. Description of the Related Art Conventionally, a photosensitive resin composition and a photosensitive element obtained by using the same have been widely used as resist materials used for etching, plating and the like in the field of manufacturing printed circuit boards. The printed circuit board is formed by laminating a photosensitive film on a copper substrate, exposing the pattern, removing the unexposed portion with a developing solution, performing etching or plating treatment, and forming a pattern,
It is manufactured by a method of peeling and removing the cured portion from the substrate.

At present, a method (hereinafter, abbreviated as a plating method) of performing a plating treatment along with the pattern thinning of a printed wiring board is becoming mainstream. The photosensitive element used in the plating method is required to have resistance to plating chemicals, but with the conventional technology, if this resistance is increased, the cured film becomes hard and brittle, and in repair work, transport work, etc.
There has been a problem that a part of the cured film is peeled off or chipped off.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the above-mentioned conventional techniques, and the plating resistance, copper through-hole method and solder through-hole method
The present invention provides a photosensitive resin composition having excellent adhesion to a base metal and a photosensitive element using the same.

[0005]

The present invention has (A) a binder polymer having a carboxyl group, (B) a photopolymerization initiator, and (C) at least one polymerizable ethylenically unsaturated group in the molecule. The component (C) contains a photopolymerizable compound and is represented by the general formula (I)

[Chemical 5] (In the formula, R represents a hydrogen atom or an alkyl group, and two m
Are each independently an integer of 1 to 20, and X is

[Chemical 6] (Where n is an integer from 1 to 20) or

[Chemical 7] And a compound of formula (II)

[Chemical 8] The present invention relates to a photosensitive resin composition containing a compound represented by the above as an essential component and a photosensitive element using the same.

To improve plating resistance, adhesion, etc., the compound represented by the general formula (I) (urethane (meth) acrylate) and the compound represented by the formula (II) (γ-chloro-β-
Hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate) in combination.

The present invention will be described in detail below. Examples of the binder polymer having a carboxyl group used as the component (A) in the present invention include (meth) acrylic acid alkyl ester [(meth) acrylic acid means methacrylic acid and acrylic acid. The same applies to the following] and a copolymer of (meth) acrylic acid and a vinyl monomer copolymerizable therewith. These copolymers may be used alone or in combination of two or more.

As the (meth) acrylic acid alkyl ester, for example, (meth) acrylic acid methyl ester,
(Meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester and the like can be mentioned. Examples of vinyl monomers copolymerizable with (meth) acrylic acid alkyl ester and (meth) acrylic acid include (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) Acrylic acid diethylaminoethyl ester, methacrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth)
Acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, vinyltoluene and the like can be mentioned.

Examples of the photopolymerization initiator used as the component (B) in the present invention include benzophenone, N, N '.
-Tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N, N'-tetramethyl-4,
4'-diaminobenzophenone, 4-methoxy-4'-
Aromatic ketones such as dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrenequinone, benzoin methyl ether, benzoin ethyl ether, benzoin ether such as benzoin phenyl ether, benzoin such as methylbenzoin and ethylbenzoin, benzyl derivatives such as benzyldimethylketal, 2- (o-
Chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-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)-
2,4,5-triarylimidazole dimers such as 4,5-diphenylimidazole dimer and 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine, 1 , 7-bis (9,9'-acridinyl) heptane and other acridine derivatives. These may be used alone or in combination of two or more.

Examples of the component (C) other than the compounds represented by the general formula (I) and the formula (II), which are essential components, include, for example, polyethylene glycol di (meth) acrylate ( Number of ethylene groups is 2 to 1
4), trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate (propylene Compounds having a number of groups of 2 to 14), dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like, obtained by reacting α, β-unsaturated carboxylic acid with a polyhydric alcohol, Bisphenol A dioxyethylene di (meth)
Acrylate, bisphenol A trioxyethylene di (meth) acrylate, bisphenol A decaoxyethylene di (meth) acrylate and other bisphenol A dioxyethylene di (meth) acrylate, trimethylolpropane triglycidyl ether triacrylate,
Compounds obtained by adding α, β-unsaturated carboxylic acid to glycidyl group-containing compounds such as bisphenol A diglycidyl ether acrylate, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid Butyl ester, (meth) acrylic acid 2
Examples thereof include alkyl esters of (meth) acrylic acid such as ethylhexyl ester.

In the present invention, the blending amount of the component (A) is
The total amount of the components (A) and (C) is preferably 40 to 80 parts by weight based on 100 parts by weight. 40
If it is less than 1 part by weight, the photocured product tends to be brittle, and when used as a photosensitive element, the coating property tends to be poor,
If it exceeds 80 parts by weight, the sensitivity tends to be insufficient.

The amount of the component (C) is 20 to 6 relative to 100 parts by weight of the total amount of the components (A) and (C).
It is preferably in the range of 0 parts by weight. This blend amount is 2
If the amount is less than 0 parts by weight, the sensitivity tends to be insufficient,
If it exceeds the amount by weight, the photocured product tends to become brittle.

The compounding amount of the compound represented by the general formula (I), which is an essential component in the component (C), is 100 parts by weight of the component (C) in terms of sensitivity, adhesion, plating resistance and the like. The amount is preferably 10 to 90 parts by weight, more preferably 60 to 90 parts by weight. M and n in the general formula (I) are integers of 1 to 20. Two m
May be the same or different from each other. The compounding amount of the compound of formula (II) which is an essential component in the component (C) is 10 to 90 parts by weight based on 100 parts by weight of the component (C) from the viewpoints of sensitivity, adhesion, plating resistance and the like. It is preferably 10 to 40 parts by weight, and more preferably 10 to 40 parts by weight.

The blending amount of the component (B) is 0.1 to 20 relative to 100 parts by weight of the total amount of the components (A) and (C).
It is preferably part by weight. If it is less than 0.1 parts by weight, the sensitivity tends to be insufficient, and if it exceeds 20 parts by weight, the absorption on the surface of the composition is increased during exposure, and the internal photocuring tends to be insufficient. .

Dyes, color formers, plasticizers, pigments, flame retardants, stabilizers, adhesion promoters, etc. may be added to the photosensitive resin composition of the present invention as required.

In the photosensitive resin composition of the present invention, the above respective components are dissolved in a solvent such as toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, chloroform, methylene chloride, A uniform solution can be obtained by dissolving and mixing in methyl alcohol, ethyl alcohol, or the like.

The photosensitive resin composition of the present invention can also be used as a photosensitive element by coating it on a support and drying it. As the support, a polymer film, for example, a film made of polyethylene terephthalate, polypropylene, polyethylene or the like is used, and a polyethylene terephthalate film is preferable. Since these polymer films must be removable from the photosensitive layer later, they must not be surface-treated or made of a material that makes them impossible to remove. The thickness of these polymer films is usually 5 to 100 μm, preferably 10 to 30 μm. One of these polymer films may be laminated on both sides of the photosensitive layer as a support film for the photosensitive layer and the other as a protective film for the photosensitive layer.

In producing a photoresist image using the photosensitive element of the present invention, when the above-mentioned protective film is present, the protective film is removed and then the photosensitive layer is pressed against the substrate while heating. By doing so. The surface to be laminated is usually a metal surface, but is not particularly limited. The heating and pressure bonding of the photosensitive layer are usually 90 to 130.
It is carried out at a temperature of 3 ° C. and a pressure of 3 kg / cm ² , but these conditions are not particularly limited. If the photosensitive layer is heated as described above, it is not necessary to preheat the substrate in advance, but the substrate may be preheated in order to further improve the stacking property.

The photosensitive layer thus laminated is
It is then imagewise exposed to actinic light using a negative or positive film. At this time, when the polymer film existing on the photosensitive layer is transparent, it may be exposed as it is, and when it is opaque, it is of course necessary to remove it. From the viewpoint of protecting the photosensitive layer, it is preferable that the polymer film is transparent, and the polymer film is allowed to remain and exposed through it.

As the active light, light generated from a known active light source such as carbon arc, mercury vapor arc, xenon arc, etc. is used. The sensitivity of the photoinitiator contained in the photosensitive layer is usually maximum in the UV region, in which case the actinic light source should be one which emits UV radiation effectively. Of course, when the photoinitiator is one that is sensitive to visible light, for example, 9,10-phenanthrenequinone, visible light is used as the active light, and the light source is a light source other than those mentioned above. For flood light bulb,
Solar lamps are also used.

Then, after the exposure, if a polymer film or the like is present on the photosensitive layer, it is removed, and then an alkaline aqueous solution is used, for example, spraying, rocking dipping, brushing, scraping, etc. The unexposed portion is removed and development is performed by a known method. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium or potassium hydroxides, alkali carbonates such as lithium, sodium or potassium carbonates or bicarbonates, alkali metals such as potassium phosphate and sodium phosphate. Phosphates, alkali metal pyrophosphates such as sodium pyrophosphate, potassium pyrophosphate and the like are used, and an aqueous solution of sodium carbonate is particularly preferable. The pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11, and
The temperature is adjusted according to the developability of the photosensitive layer. A surface active agent, a defoaming agent, and a small amount of an organic solvent for accelerating the development may be mixed in the alkaline aqueous solution.

Further, when manufacturing a printed wiring board, the surface of the exposed substrate is treated by a known method such as etching or plating using the developed photoresist image as a mask. Next, the photoresist image is usually stripped with an aqueous solution having a stronger alkaline property than the alkaline solution used for the development. As the strong alkaline aqueous solution, for example, a 1 to 5 wt% sodium hydroxide aqueous solution or the like is used.

[0023]

EXAMPLES Next, the present invention will be described in detail with reference to Examples.

Examples 1 to 3 and Comparative Examples 1 to 5 Methacrylic acid / Methyl methacrylate / Ethyl acrylate / Ethyl methacrylate (Polymerization ratio 22/45/27/6
(Weight ratio), weight average molecular weight 100,000 40 wt% methyl cellosolve / toluene (weight ratio 6/4) solution 150 g (solid content 60 g) ((A) component), 2- (o-
Chlorophenyl) -4,5-diphenylimidazole dimer 3.0 g, leuco crystal violet 0.5
g, malachite green 0.05 g, methyl ethyl ketone 10 g, toluene 10 g, methanol 3 g, p-toluenesulfonic acid amide 4.0 g and N, N′-tetraethyl-4,4′-diaminobenzophenone 0.2 g (above (B) component) ) Was blended to obtain a solution.

The component (C) shown in Table 1 was dissolved in this solution to obtain a solution of a photosensitive resin composition. Then, the solution of the photosensitive resin composition was uniformly applied on a polyethylene terephthalate film having a thickness of 25 μm and dried by a hot air convection dryer at 100 ° C. for about 10 minutes to obtain a photosensitive element. The film thickness of the photosensitive resin composition layer after drying was 50 μm.

On the other hand, the copper surface of a copper-clad laminate (trade name: MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.), which is a glass epoxy material in which copper foil (thickness 35 μm) is laminated on both sides, is # 600.
Polishing using a polishing machine (manufactured by Sankei Co., Ltd.) having an appropriate brush, washing with water, and drying with an air stream, heating the obtained copper-clad laminate to 80 ° C., and exposing the copper surface to the above-mentioned photosensitivity. The resin composition layer was laminated while being heated to 120 ° C.

Next, using an exposing machine (manufactured by Oak Co., Ltd.) HMW-201B having a high-pressure mercury lamp, a 21-step Stofer negative step tablet was placed on the test piece and exposed at 60 mJ / cm ² . Next, the polyethylene terephthalate film was peeled off, and an unexposed portion was removed by spraying a 1 wt% sodium carbonate aqueous solution at 30 ° C. for 60 seconds. Furthermore, the photosensitivity of the photosensitive resin composition was evaluated by measuring the number of steps of the step tablet of the photocured film formed on the copper-clad laminate. The results are shown in Table 1. The light sensitivity is indicated by the number of steps of the step tablet, and the higher the number of steps of this step tablet, the higher the light sensitivity.

Further, the adhesiveness is represented by the line width (μm) remaining after the development without peeling. The smaller the adhesiveness number is, the closer the adhesiveness is to the copper-clad laminate without peeling from the copper-clad laminate even with a thin line, indicating that the adhesiveness is high.

The plating resistance was determined by laminating as described above and exposing with a predetermined exposure amount. Then, after development with the above developing solution, degreasing (PC-455 (Meltex Co., Ltd.) 25%) 5 minutes immersion → water washing → soft etch (ammonium persulfate 150 g / l) 2 minutes immersion → water washing → 10% sulfuric acid 1 minute immersion Pre-treatment in order, copper sulfate plating bath (copper sulfate 75g / l, sulfuric acid 190g / l, chlorine ion 50ppm,
Copper glume PCM (manufactured by Meltex Co., Ltd., 5 ml / liter), and copper sulfate plating was performed at room temperature at 3 A / dm ² for 40 minutes. Then, wash with water and add 10% borofluoric acid to 1
Soak for minutes, solder plating bath (45% tin borofluoride 64
ml / liter, 45% lead borofluoride 22 ml / liter, 42% borofluoric acid 200 ml / liter, Pultin LA conductivity salt (manufactured by Meltex) 20 g / liter,
Pultin LA Starter (Meltex) 40ml
/ L) and solder plating at room temperature at 1.5A / dm ²
It went for 5 minutes.

After washing with water and drying, cellophane tape was immediately applied to check the plating resistance, and the tape was peeled in the vertical direction (90 ° peel-off test) to see if the resist was peeled. Further, after peeling the resist, the presence or absence of chipping of the solder plating was observed from above with an optical microscope. When the solder plating is removed, the solder deposited by plating through the transparent resist is observed. The above results are summarized in Table 1.

[0031]

[Table 1]

As is apparent from Table 1, the compound represented by the general formula (I) (urethane (meth) acrylate) and the compound represented by the formula (II) (γ-chloro-β-hydroxypropyl-β'-methacryl) Royloxyethyl-o-
It is possible to obtain a photosensitive resin composition having high sensitivity, excellent adhesion, and good plating resistance by using it in combination with phthalate).

[0033]

EFFECTS OF THE INVENTION The photosensitive resin composition of the present invention and the photosensitive element using the same are excellent in sensitivity, adhesiveness to a base metal,
It has excellent resistance to plating.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G03F 7/038 H05K 3/00 F 3/18 D 7511-4E (72) Inventor Taku Kawaguchi Ibaraki 4-13-1 Higashimachi, Hitachi City Inside the Yamazaki Factory, Hitachi Chemical Co., Ltd. (72) Inventor Yoshitaka Minami 4-13-1 Higashimachi, Hitachi City, Ibaraki Prefecture Inside the Yamazaki Factory, Hitachi Chemical Co., Ltd.

Claims (4)

[Claims] 1. A binder polymer having (A) a carboxyl group, (B) a photopolymerization initiator, and (C) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, The component (C) has the general formula (I): (In the formula, R represents a hydrogen atom or an alkyl group, and two m
Are each independently an integer of 1 to 20, and X is (Where n is an integer from 1 to 20) or And a compound of formula (II) A photosensitive resin composition containing as an essential component a compound represented by: 2. The content of the urethane unsaturated compound represented by the general formula (I) in the component (C) is 100% of the component (C).
The photosensitive resin composition according to claim 1, which is 10 to 90 parts by weight with respect to parts by weight. 3. The use ratio of the component (A), the component (B) and the component (C) is 40 to 80 parts by weight of the component (B) 100 parts by weight of the total amount of the components (A) and (C). Against 0.1
20 parts by weight and (C) 20 to 60 parts by weight (however, (A)
The total amount of the component and the component (C) is 100 parts by weight), The photosensitive resin composition according to claim 1, 2 or 3. 4. A photosensitive element obtained by applying the photosensitive resin composition according to claim 1, 2 or 3 onto a support and drying it.