JP3173191B2 - Photosensitive resin composition and photosensitive element using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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 In the fields of manufacturing printed wiring boards, precision processing of metals, etc., chemicals of base materials such as etching and plating are used.
It is known to use a photosensitive resin composition and a photosensitive element using the same as a resist material when using an electrical method. As the photosensitive element, those obtained by laminating a photosensitive resin composition on a support are widely used.

The photosensitive resin composition is cured by light, and the uncured portion is dissolved in an aqueous alkali solution such as sodium carbonate. A polymer having a group capable of dissolving in a water / alkaline medium such as a carboxylic acid, a carboxylic anhydride, a sulfonic acid, a phenolic or alcoholic hydroxyl group, or the like, A copolymer is used (Japanese Patent Publication No. Sho 3
JP-A-5-14065, JP-B-39-1112, etc.). However, these compositions cannot produce a high-precision relief image required for printed wiring boards at present and are not practical.

Japanese Patent Publication No. 58-12577 discloses a method of adhering to a flexible metal, and performing cold flow or leaching from the end of a resist when storing a photosensitive element in a roll shape. A composition intended to reduce edge fusion) has been proposed, but the stripping time is long due to copolymerization of long-chain methacrylate. There are problems such as falling off. Japanese Patent Publication No. 36924/1989 discloses a photosensitive element as an excellent etching or plating resist and having a low cold flow property.
However, these resin compositions also have problems such as swelling of the photocured portion due to the use of a copolymer having a high water absorption to obtain fast developability and releasability, tearing of the tent, and jagged lines. .

[0005]

SUMMARY OF THE INVENTION The present invention is to provide a photosensitive resin composition which solves the above-mentioned drawbacks, obtains excellent adhesion, tent strength and peelability, and enables a highly accurate relief image. And a photosensitive element using the same.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a photopolymer having (A) a carboxyl group-containing binder polymer, (B) a photopolymerization initiator, and (C) at least one polymerizable ethylenically unsaturated bond in a molecule. A compound comprising a polymerizable compound, wherein the component (C) is represented by the general formula (I):

Embedded image The present invention relates to a photosensitive resin composition containing (R represents-(CH ₂ ) _n- , n represents an integer of 1 to 20) as an essential component, and a photosensitive element using the same.

Hereinafter, the present invention will be described in detail. As the carboxyl group-containing binder poromer used as the component (A) in the present invention, for example, (meth) acrylic acid alkyl ester [(meth) acrylic acid means methacrylic acid and acrylic acid. The same applies hereinafter), and copolymers of (meth) allylic acid and a vinyl monomer copolymerizable therewith. These copolymers can be used alone or in combination of two or more.

The alkyl (meth) acrylate includes, for example, methyl (meth) acrylate,
Examples include ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Examples of the vinyl monomer copolymerizable with the alkyl (meth) acrylate and the (meth) acrylic acid include, for example, tetrahydrofurfuryl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and (meth) acrylate. 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.

The photopolymerization initiator used as the component (B) in the present invention includes, for example, benzophenone, N, N '
-Tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N, N-tetramethyl-4,4 '
Aromatic ketones such as diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-ethylanthraquinone and phenanthrenequinone; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether; methyl benzoin; ethyl benzoin; Benzoin, benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer 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
2,4,5-triarylimidazole dimer such as -diphenylimidazole dimer, 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine, 1,7- Screw (9, 9 '
Acridine derivatives such as -acridinyl) heptane; These can be used alone or in combination of two or more.

Among the photopolymerizable compounds having at least one polymerizable ethylenically unsaturated bond used as the component (C) in the present invention, the compound represented by the general formula (I) contained as an essential component includes: For example, Uniresin K-1000A (n = 6 in the general formula (I), trade name of Shin-Nakamura Chemical Co., Ltd.), Uniresin K-2000A (n = 12 in the general formula (I), trade name of Shin-Nakamura Chemical Co., Ltd.) ) Etc. are used.

As the component (C), compounds other than the above two essential components include, for example, polyethylene glycol di (meth) acrylate (when the number of ethylene groups is 2 to 2).
14), trimethylolpropanedi (meth) acrylate, trimethylolpropanetri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, polypropylene glycol di (meth) acrylate (propylene) A compound obtained by reacting a polyhydric alcohol such as dipentaerythritol penta (meth) acrylate or dipentaerythritol hexa (meth) acrylate with an α, β-unsaturated carboxylic acid; Bisphenol A dioxyethylene di (ethylene glycol) such as bisphenol A dioxyethylene di (meth) acrylate, bisphenol A trioxyethylene di (meth) acrylate, bisphenol A decaoxyethylene di (meth) acrylate Compounds obtained by adding an α, β-unsaturated carboxylic acid to a glycidyl group-containing compound such as (meth) acrylate, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether acrylate, etc. Esterified product of a polyvalent carboxylic acid and a substance having a hydroxyl group and an ethylenically unsaturated group such as β-hydroxyethyl (meth) acrylate, (meth) acrylic acid methyl ester,
Examples of the alkyl ester of (meth) acrylic acid such as ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

In the present invention, the amount of component (A) is
The content is preferably in the range of 40 to 80 parts by weight based on 100 parts by weight of the total of the components (A) and (C). When the amount is less than 40 parts by weight, the photocured product tends to become brittle, and when used as a photosensitive film, the coating properties tend to be poor, and
When the amount exceeds the weight part, the sensitivity tends to be insufficient.

The compounding amount of the component (C) depends on the amount of the component (A).
And 20 to 60 parts by weight based on a total of 100 parts by weight of component (C).
It is preferred to be in the range of parts by weight. When the blending amount is 20
If the amount is less than part by weight, the sensitivity tends to be insufficient, and if it exceeds 60 parts by weight, the photocured product tends to become brittle.

The amount of the monomer represented by the general formula (I), which is an essential component in the component (C), is as follows:
The amount is preferably 5 to 40 parts by weight based on 00 parts by weight. If the amount is less than 5 parts by weight, the peeling time tends to be long, and if it exceeds 40 parts by weight, the tent strength tends to be weak. N in the general formula (I) is an integer of 1 to 20. If n exceeds 20, sensitivity, adhesion, and strength will be poor.

The amount of the photopolymerization initiator component (B) is 0.1 part by weight based on 100 parts by weight of the total of the components (A) and (C).
It is preferred to be in the range of 1 to 20 parts by weight. If the amount is less than 0.1 part by weight, the sensitivity tends to be insufficient. If the amount exceeds 20 parts by weight, the absorption on the surface of the composition upon exposure increases, and the internal light curing tends to be insufficient. .

The photosensitive resin composition of the present invention may contain a dye, a color former, a plasticizer, a pigment, a flame retardant, a stabilizer, an adhesion promoter, and the like, if necessary.

In the photosensitive resin composition of the present invention, each of the above components is dissolved in a solvent dissolving them, for example, toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, methyl cellosolve, ethyl cellosolve, chloroform, methylene chloride, By dissolving and mixing in methyl alcohol, ethyl alcohol or the like, a uniform solution can be obtained.

The photosensitive resin composition of the present invention can be coated on a support, dried and used as a photosensitive element. 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 should not be made of a material that cannot be removed or have been subjected to a surface treatment. 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, if the protective film is present, the protective film is removed and then the photosensitive layer is pressed against a substrate while heating. To be laminated. The surface to be laminated is usually a metal surface, but is not particularly limited. Heating and pressure bonding of the photosensitive layer are usually 90 to 130.
C. and a compression 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 it is a matter of course that the substrate can be preheated to further improve the lamination property.

The photosensitive layer thus completed in lamination is
It 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 it is, and if it is opaque, it must be removed. From the viewpoint of protection of the photosensitive layer, the polymer film is transparent, and it is preferable to expose the polymer film while leaving the polymer film remaining.

As the active light, a light generated from a known active light source, for example, a carbon arc, a mercury vapor arc, a xenon arc, or the like is used. Since the sensitivity of the photoinitiator contained in the photosensitive layer is usually maximal in the ultraviolet range, the active light source should then effectively emit ultraviolet light. Of course, when the photoinitiator is sensitive to visible light, for example, 9,10-phenanthrenequinone or the like, visible light is used as the active light, and a light source other than the above is used as the light source. For flood light bulb,
A solar lamp or the like is also used.

Next, after the exposure, if a polymer film is present on the photosensitive layer, the polymer film is removed and then removed using a known aqueous solution such as spraying, rocking immersion, brushing, and scrubbing using an aqueous alkali solution. The unexposed portion is removed by a method and developed. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium or potassium hydroxide, alkali carbonates such as lithium, sodium or potassium carbonate or bicarbonate, and alkali metals such as potassium phosphate and sodium phosphate. Phosphates, alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used, and an aqueous solution of sodium carbonate is particularly preferable. The pH of the aqueous alkali solution used for development is preferably between 9 and 11, and the temperature is adjusted according to the developability of the photosensitive layer. A surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed in the alkaline aqueous solution.

Further, when manufacturing a printed wiring board, the exposed surface of the substrate is treated by a known method such as etching or plating using the developed photoresist image as a mask. The photoresist image is then typically stripped with an aqueous solution that is more alkaline than the aqueous alkaline solution used for development. As the strong alkaline aqueous solution, for example, an aqueous solution of 1 to 5% by weight of sodium hydroxide is used.

[0024]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Examples 1-2 and Comparative Examples 1-3 Methacrylic acid / methyl methacrylate / ethyl acrylate / ethyl methacrylate (polymerization ratio 22/45/27/6)
(Weight ratio), 150 g of a 40% by weight methylcellosolve / toluene (weight ratio 6/4) solution having a weight average molecular weight of 110,000
(Solid content 60 g) (component (A)), tribromomethylphenylsulfone 1.0 g, leuco crystal violet 1 g, malachite green 0.05 g, methyl ethyl ketone 10 g, toluene 10 g, methanol 3 g, benzophenone 4.5 g (component (B) )) And 0.2 g of N, N'-tetraethyl-4,4'-diaminobenzophenone (component (B)) to give a solution. The component (C) shown in Table 1 was dissolved in this solution to obtain a solution of the photosensitive resin composition. Next, the solution of the photosensitive resin composition was uniformly applied on a 25 μm-thick polyethylene terephthalate film, and dried with a hot air convection dryer at 100 ° C. for about 10 minutes to obtain a photosensitive element. The dried film thickness of the photosensitive resin composition layer was 50 μm.

On the other hand, the copper surface of a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E-61) which is a glass epoxy material having a copper foil (thickness: 35 μm) laminated on both sides is # 600.
Polishing using a polishing machine (manufactured by Sankeisha Co., Ltd.) having a considerable brush, washing with water, and drying in an air stream, heating the obtained copper-clad laminate to 80 ° C. The conductive resin composition layer was laminated while being heated to 120 ° C. Next, an exposure machine (manufactured by Oak Co., Ltd.) HM having a high pressure mercury lamp
Using a W-201B as a negative, a 21-step Stofa step tablet was placed on the test piece and exposed to 60 mJ / cm ² . Next, the polyethylene terephthalate film was peeled off, and an unexposed portion was removed by spraying a 1% by weight aqueous solution of sodium carbonate 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. Table 1 shows the results. The light sensitivity is indicated by the number of steps of the step tablet. The higher the number of steps of the step tablet, the higher the light sensitivity.

Another test piece was exposed at 60 mJ / cm ² to remove the polyethylene terephthalate film, and subjected to a cross cut test (JIS K-5400). Also, 5cm ×
After exposure of a 5 cm test piece at 60 mJ / cm ² and development for 60 seconds, 5
It was immersed in 3% by weight NaOH heated to 0 ° C., the time required for the resist to peel off was measured, and the size of the peeled piece was measured at the same time.

Exposure and development were carried out in the same manner as above using a 100 μm line & space negative, and a cupric chloride etching solution was sprayed with a spray etching apparatus made by Sankei at a spray pressure of 3 kgf / cm ² for 60 seconds, and tested. The piece was etched, the resist was stripped, and the line was observed for nicks. Further, the sample after the cross-cut test was etched, and the infiltration of the etching solution at the cut portion was observed.

Next, a laminate of the photosensitive resin composition was laminated on both sides of a base material in which 100 holes each having a diameter of 6 mm were formed in a copper-clad laminate having a thickness of 1.6 mm, and exposed to 60 mJ / cm ² for 60 seconds. Developed.

Next, the strength of this hole was measured by a rheometer (manufactured by FUDOH) using a cylinder having an insertion diameter of 1.5 mmφ to measure the strength up to breaking and elongation. These results are summarized in Table 1.

[0030]

[Table 1]

As is apparent from Table 1, by containing the compound represented by the general formula (I), a photosensitive resin having excellent adhesion, high tent strength, short release time, and small release piece size is obtained. A composition can be obtained.

[0032]

The photosensitive resin composition of the present invention and the photosensitive element using the same are excellent in adhesion to metal, tent strength, peeling property and the like.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H05K 3/00 H01L 21/30 502R (56) References JP-A-62-43642 (JP, A) JP-A-1-277232 (JP, A) JP-A-4-85315 (JP, A) JP-A-63-98651 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 7/027 501 G03F 7/028 G03F 7 / 033 G03F 7/038

Claims (4)

(57) [Claims] 1. A composition comprising (A) a carboxyl group-containing binder polymer, (B) a photopolymerization initiator, and (C) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in a molecule. Component (C) is a compound represented by the general formula (I): (R represents — (CH ₂ ) _n — and _n represents an integer of 1 to 20) as an essential component. 2. The content of the ethylenically unsaturated compound represented by the general formula (I) in the component (C) is 100%.
The photosensitive resin composition according to claim 1, wherein the amount is 5 to 40 parts by weight based on parts by weight. 3. The use ratio of the components (A), (B) and (C) is as follows: (A) 40 to 80 parts by weight (B) (A) + (C) = 100 parts by weight; ~
The photosensitive resin composition according to claim 1, 2 or 3, wherein the amount is 20 parts by weight (C) 20 to 60 parts by weight (provided that (A) + (C) = 100 parts by weight). 4. A photosensitive element, wherein the photosensitive resin composition according to claim 1, 2 or 3 is applied on a support and dried.