JPH08286372A - Photosensitive resin composition, and photosensitive element using this composition - Google Patents

Abstract

PURPOSE: To provide a photosensitive resin composition and a photosensitive element using this composition satisfying various requirements and having mechanical strength, chemical resistance, and softness by using a compound bonded between an isocyanuric ring and a (metha)acrylate with a polyethylene glycol group or a polypropylene glycol group, which is soft, and an examethylene group as an ethylene unsaturated compound. CONSTITUTION: (A) a binder polymer containing a carboxyl group, (B) a photopolymerized compound having a polymerizable ethylene-like unsaturated group in a molecule, and (C) a photopolymerization initiator are contained, and (B) contains compounds represented by formulas I as the essential ingredient. In formula I, R<1> represents a divalent organic group, and R<2> includes conposition which is represented by a formula II as an essential component and in formula II, R<3> represents a hydrogenn atom or a methyl group, X represents an alkylene oxide group, and (n) is an integer of 1-14.

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, in the field of manufacturing printed circuit boards, as a resist material used for etching, plating, etc., a photosensitive resin composition and a photosensitive element obtained by using a support and a protective film therefor are widely used. Has been. The printed circuit board is formed by laminating a photosensitive film on a copper substrate, pattern-exposing it, removing the unexposed part with a developing solution, etching or plating it to form a pattern, and then curing the part. It is manufactured by a method of peeling and removing from the substrate.

As a developing solution for removing the unexposed portion, an alkaline developing type using a sodium hydrogen carbonate solution or the like is mainly used, and the developing solution is usually capable of dissolving the photosensitive layer to some extent. Used, the photosensitive resin composition is dissolved or dispersed in the developer at the time of use. With the recent increase in the density of printed wiring boards, the contact area between the copper substrate and the patterned photosensitive layer becomes smaller, resulting in excellent adhesion, mechanical strength, chemical resistance in the development, etching or plating treatment steps. Flexibility is required.

Among these properties, a method of using a photopolymerizable compound having an isocyanurate ring for improving chemical resistance is disclosed in JP-A-61-77844 and JP-A-6-76844.
2-290705, JP 61-14212, JP 59-222480, JP 1-14.
No. 190, JP-A-57-55914, JP-A-5-216224, and JP-A-5-273754, the cured film is hard and brittle.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the conventional techniques and solves the problems of isocyanuric ring and (meth)
A flexible polyalkylene oxide group (polyethylene oxide group, polypropylene oxide group, etc.) and an alkylene group (hexamethylene group, etc.) bonded between acrylates are used as an ethylenically unsaturated compound to satisfy various requirements. And a photosensitive resin composition having mechanical strength, chemical resistance and flexibility, and a photosensitive element using the same.

[0006]

The present invention provides (A) a binder polymer having a carboxyl group, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group in the molecule, and (C) a photoinitiator. And the component (B) has the general formula (I)

Embedded image (In the formula, R ¹ represents a divalent organic group, and R ² represents the general formula (II)

[Chemical 4] (In the formula, R ³ represents a hydrogen atom or a methyl group, X represents an alkylene oxide group, and n is an integer of 1 to 14) and a photosensitive resin composition containing the compound represented by the formula as an essential component. Regarding things. The present invention also relates to a photosensitive element obtained by applying the photosensitive resin composition on a support and drying the composition.

The photosensitive resin composition of the present invention comprises (A) a binder polymer having a carboxyl group, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group in the molecule, and (C) a photoinitiator. In addition, the component (B) contains the compound represented by the general formula (I) as an essential component.

Examples of the binder polymer having a carboxyl group (A) in the present invention include (meth) acrylic acid ((meth) acrylic acid means methacrylic acid and acrylic acid. The same applies hereinafter) and these. Examples thereof include a copolymer with a copolymerizable vinyl monomer, and these copolymers are used alone or in combination of two or more kinds.

The vinyl monomer is not particularly limited, and examples thereof include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester, ( (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 ((meth) acrylate means acrylate and methacrylate; the same applies hereinafter), 2,2,3,3-tetrafluoropropyl (meth) acrylate acrylamide, diacetone acrylamide, styrene, vinyl Toluene and the like can be mentioned.

(A) The binder polymer having a carboxyl group is soluble or swellable in an alkaline aqueous solution (for example, 1 to 3% by weight aqueous solution of sodium carbonate or potassium carbonate). Etc. are preferable. The acid value is preferably 100 to 500. When the acid value is less than 100, the developing time tends to be delayed, and when it exceeds 500, the developing solution resistance of the photocured resist tends to decrease. The weight average molecular weight (GPC measurement, converted to polystyrene) is 2
It is preferably from 30,000 to 300,000. If the weight average molecular weight is less than 30,000, the resistance to developing solution tends to decrease, and if it exceeds 300,000, the developing time tends to be long.

In the present invention, the compound represented by the above general formula (I) contained as an essential component in the photopolymerizable compound (B) having at least one polymerizable ethylenically unsaturated group in the molecule is In the general formula (I), the divalent organic group represented by R ¹ is not particularly limited, and for example,
Methylene group, ethylene group, propylene group, isopropylene group, butylene group, isobutylene group, pentylene group, neopentylene group, hexylene group, heptylene group, octylene group, 2-ethyl-hexylene group, nonylene group, decylene group and the like. . Similarly, the general formula is R ² (I
In I), the alkylene oxide group represented by X is not particularly limited, and examples thereof include an ethylene oxide group, a propylene oxide group, a butylene oxide group, a pentylene oxide group, and a hexylene oxide group. , A propylene oxide group is preferred. In addition, as the bonding direction of the propylene oxide group,

Embedded image There are two types. In the general formula (II), n is 1 to 1
It must be an integer of 4 and is preferably 2-14. When n exceeds 14, the mechanical strength decreases.

Examples of the compound represented by the above general formula (I) include compounds represented by the general formula (II-1), general formula (II-2) or general formula (II-3), and Formula (III)
It is obtained by a reaction with a compound represented by

[Chemical 6] (In the formula, R ³ and n have the same meaning as in formula (II), and m is an integer of 3 to 6)

[Chemical 7] (In the formula, R ¹ has the same meaning as in formula (I))

In the general formula (II-2), the propylene oxide unit of this block segment is
For convenience of notation, the bonding position of the methyl group is on the carbon atom two adjacent to the oxygen atom, but it is not limited to this structure,

Embedded image Etc. are also included.

The compound represented by the above general formula (I) is commercially available, for example, NK oligo UA-21.
(In the general formula _{(I), R 2 = -CH} 3, X = -CH 2 CH 2 O
-, N = 4 (average value), Shin-Nakamura Chemical Co., Ltd. product name),
NK oligo UA-41 (in the general formula (I), R ₂ = -C
_{H 3, X = -CH 2 -CH} (CH 3) -O- or -CH (CH
_{3) -CH 2 -O-, n =} 5 ( average value), Shin-Nakamura Chemical Co.
(Trade name), NK oligo UA-42 (general formula (I)
_{In, R 2 = -CH 3, X} = -CH 2 -CH (CH 3) -O- or _{-CH (CH 3) -CH 2 -O-} , n = 9 ( average value), Shin-Nakamura Chemical Co. ( Trade name), NK oligo UA-44
(In the general formula _{(I), R 2 = -H} , X = -CH 2 -CH (C
H ₃₎ -O- or _{-CH (CH 3) -CH 2 -O-} , n = 6
(Average value), Shin-Nakamura Chemical Co., Ltd. product name, etc.

Examples of the compound other than the compound represented by the above general formula (I) which is an essential component in the component (B) in the present invention include, for example, polyhydric alcohol and α, β-unsaturated carboxylic acid. (Polyethylene glycol di (meth) acrylate (having 2 to 14 ethylene groups), trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (Meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate (having 2 to 14 propylene groups), dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) Acrylate, etc.), containing glycidyl group Compound obtained by adding α, β-unsaturated carboxylic acid to the compound (bisphenol A
Bisphenol A dioxyethylene di (meth), such as dioxyethylene di (meth) acrylate, bisphenol A trioxyethylene di (meth) acrylate, bisphenol A decaoxyethylene di (meth) acrylate
Acrylate, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether acrylate, etc.), alkyl ester of (meth) acrylic acid ((meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid Butyl ester, (meth) acrylic acid 2-ethylhexyl ester, etc.) and the like.

The (C) photoinitiator in the present invention includes:
For example, aromatic ketones (benzophenone, N, N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N, N'-tetramethyl-4,4'-diaminobenzophenone, 4-methoxy-4'- Dimethylaminobenzophenone, 2-ethylanthraquinone, phenanthrenequinone, etc.), benzoin (benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, and other benzoin ethers, methylbenzoin, ethylbenzoin, etc.), benzyl derivatives (benzyldimethylketal, etc.), 2 , 4,5-Triarylimidazole dimer (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) -4,5-diphenylimidazole dimer, 2- (p-methylmercaptophenyl)
-4,5-diphenylimidazole dimer), acridine derivative (9-phenylacridine, 1,7-bis (9,9'-acridinyl) heptane, etc.) and the like. These are used alone or in combination of two or more.

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

The blending amount of the component (B) in the present invention is
The total amount of the components (A) and (B) is preferably 20 to 60 parts by weight based on 100 parts by weight. If the amount is less than 20 parts by weight, the sensitivity tends to be insufficient, and if it exceeds 60 parts by weight, the photocured product tends to be brittle.

The compounding amount of the compound represented by the general formula (I), which is an essential component in the component (B) in the present invention, is
The total amount of the components (A) and (B) is 100 parts by weight, preferably 3 parts by weight or more, and more preferably 5 to 40 parts by weight. If the amount is less than 3 parts by weight, the sensitivity, adhesion, plating resistance, etc. tend to be poor.

The blending amount of the component (C) in the present invention is
It is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B). If the content 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 during exposure increases and the internal photo-curing does not occur. Tends to be insufficient.

The photosensitive resin composition of the present invention may optionally contain dyes, color formers, plasticizers, pigments, flame retardants, stabilizers,
Adhesion imparting agents and the like can be added.

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 homogeneous solution can be obtained by dissolving and mixing in methyl alcohol, ethyl alcohol, or the like.

The photosensitive element of the present invention can be prepared by applying the photosensitive resin composition of the present invention on a support and drying it.

Examples of the support include polymer films such as films made of polyethylene terephthalate, polypropylene, polyethylene and the like.
A polyethylene terephthalate film is preferred. Since these polymer films need to be removed from the photosensitive layer later, they should not be surface-treated or made of a material that makes them impossible to remove.

The thickness of these polymer films is 5 to 1
The thickness is preferably 00 μm, more preferably 10 to 30 μm. In addition, one of these polymer films can be laminated on both sides of the photosensitive layer, one as a supporting film for the photosensitive layer and the other as a protective film for the photosensitive layer.

As a method for producing a photoresist image using the photosensitive element of the present invention, when the above-mentioned protective film is present, after removing the protective film,
Examples thereof include a method of laminating by pressing the photosensitive layer onto a substrate while heating. The surface to be laminated is usually a metal surface, but is not particularly limited.

The heating temperature of the photosensitive layer is not particularly limited and may be 9
The temperature is preferably 0 to 130 ° C. The pressure for pressing the photosensitive layer is not particularly limited, and is preferably 3 kg / cm ² . If the photosensitive layer is heated as described above, it is not necessary to preheat the substrate in advance, but the substrate can 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, the polymer film is transparent, and the polymer film is left as it is.
It is preferable to expose through it.

As the active light, light generated from a known active light source, for example, carbon arc, mercury vapor arc, xenon arc or the like is used. Since the sensitivity of the photoinitiator contained in the photosensitive layer is usually the maximum in the ultraviolet region, in this case, it is preferable that the active light source emits ultraviolet light effectively. 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 the light source is other than those described above. Photo flood lamps and sun lamps are also used.

After the exposure, if a polymer film or the like is present on the photosensitive layer after the exposure, 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 hydroxide (lithium, sodium or potassium hydroxide, etc.), alkali carbonate (lithium, sodium or potassium carbonate or bicarbonate, etc.), alkali metal phosphate (potassium phosphate). , Sodium phosphate, etc.), alkali metal pyrophosphates (sodium pyrophosphate, potassium pyrophosphate, etc.) and the like, and an aqueous solution of sodium carbonate is 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. Also,
A surface active agent, a defoaming agent, and a small amount of an organic solvent for accelerating the development can be mixed in the alkaline aqueous solution.

Further, as a method for producing a printed wiring board, there may be mentioned a method of treating the surface of the substrate exposed by using the developed photoresist image as a mask by a known method such as etching or plating. The photoresist image can then be stripped, usually with a more alkaline aqueous solution than the aqueous alkaline solution used for development. As the strong alkaline aqueous solution, for example, a 1 to 5 wt% sodium hydroxide aqueous solution or the like is used.

[0033]

EXAMPLES The present invention will be described below with reference to examples. Examples 1 to 4 and Comparative Examples 1 to 3 The materials shown in Table 1 and Table 2 were blended to obtain solutions.

[Table 1]

[Table 2]

The component (B) shown in Table 3 was dissolved in the obtained solution to obtain a solution of a photosensitive resin composition.

[Table 3]

In Table 3, the compounds used are: * 1: R in the general formula (I)¹Is -C₆H₁₂-, R³Is -CH₃,
X is -CH₂CH₂O-, n is a compound of 4 (average value), Shinchu
Mura Kogyo Co., Ltd. * 2: R in the general formula (I)¹Is -C₆H₁₂-, R³Is -CH₃,
X is -CH₂CH (CH ₃) -O- or -CH (CH₃) -C
H₂O and n are compounds of 5 (average value), manufactured by Shin-Nakamura Industry Co., Ltd. * 3: R in the general formula (I)¹Is -C₆H₁₂-, R³Is -CH₃,
X is -CH₂CH (CH₃) -O- or -CH (CH₃) -C
H₂O and n are compounds of 9 (average value), manufactured by Shin Nakamura Kogyo Co., Ltd. * 4: R in the general formula (I)¹Is -C₆H₁₂-, R³Is -H, X
Is -CH₂CH (CH₃) -O- or -CH (CH₃) -CH₂
O and n are compounds of 6 (average value), manufactured by Shin Nakamura Industry Co., Ltd. * 5: Polypropylene glycol diacrylate (Shin Nakamura
Chemical Industry Co., Ltd.) * 6: γ-chloro-β-hydroxypropyl-β′-meta
Cryloyloxyethyl-o-phthalate * 7: β-hydroxypropyl-β′-methacryloylo
Xyethyl-o-phthalate.

Next, the solution of the obtained photosensitive resin composition was uniformly applied on a polyethylene terephthalate film having a thickness of 25 μm, and dried with a hot air convection dryer at 100 ° C. to about 1 μm.
After drying for 0 minutes, a photosensitive element was obtained. 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 (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 # 6.
Polished using a polishing machine (manufactured by Sankei Co., Ltd.) with a brush equivalent to 00, washed with water, dried with an air stream, and heat the obtained copper-clad laminate to 80 ° C. Then, the photosensitive resin composition layer was laminated while being heated to 120 ° C.

Next, using a exposing machine (Oak Co., Ltd.) HMW-201B having a high-pressure mercury lamp, a Stofer 21-step step tablet was placed on the test piece as a negative and exposed at 60 mJ / cm ² . did. Next, the polyethylene terephthalate film was peeled off, a 1 wt% sodium carbonate aqueous solution was sprayed at 30 ° C. for 60 seconds to remove the unexposed portion, and then the number of steps of the step tablet of the photo-cured film formed on the copper-clad laminate. Was measured to evaluate the photosensitivity of the photosensitive resin composition, and the results are shown in Table 4. 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.

For the adhesion, the line width (μm) remaining after the development without peeling was measured, and the results are shown in Table 4. The smaller the adhesiveness number, the more closely the thin line adheres to the copper-clad laminate without peeling from the copper-clad laminate, indicating that the adhesiveness is high.

The plating resistance is 5 minutes after delamination (PC-455 (manufactured by Meltex) 25% by weight) after laminating as described above, exposing with a predetermined exposure amount, and then developing with the above developing solution. Immersion → Washing → Soft etch (Ammonium persulfate 150g / L) 2 minutes Immersion → Washing →
Pre-treatment was performed in the order of immersion in 10% by weight sulfuric acid for 1 minute, and then placed in a copper sulfate plating bath (copper sulfate 75 g / liter, sulfuric acid 190 g / liter, chloride ion 50 ppm, Copper Gream PCM (Meltex) 5 ml / liter), Copper sulfate plating was performed at room temperature at 3 A / dm ² for 40 minutes. After that, it is washed with water and immersed in 10 wt% borofluoric acid for 1 minute, and then a solder plating bath (45 wt% tin borofluoride 64 ml / liter, 45 wt% lead borofluoride 22 ml / liter, 42 wt% borofluoric acid is added. 200 ml / liter, Pultin LA Conductivity Salt (Meltex)
20 g / liter, 41 ml / liter of Pultin LA starter (manufactured by Meltex), and solder plating was performed at room temperature at 1.5 A / dm ² for 15 minutes.

In order to examine the plating resistance after washing with water and drying,
Immediately, cellophane tape was applied, and this was peeled off in the vertical direction (90 ° peel-off test), and the presence or absence of peeling of the resist was observed, and the results are shown in Table 4. In addition, after the resist was peeled off, the presence or absence of chipping of the solder plating was observed from above with an optical microscope, and the results are shown in Table 4. When the solder plating is removed, the solder deposited by plating is observed under the transparent resist through the transparent resist.

Further, another test piece was subjected to a cross-cut test (JIS-K-5400) after exposure and development with a Stopher 21-step step tablet at an exposure amount showing 8 steps, and the results are shown in Table 4. It was

[0043]

[Table 4]

As is clear from Table 4, Examples 1 to 4 within the scope of the present invention have good plating resistance and excellent adhesion and crosscutting properties.

[0045]

The photosensitive resin composition according to claim 1 has excellent adhesion, chemical resistance and flexibility. Claim 2
The described photosensitive resin composition exhibits the effects of the photosensitive resin composition according to claim 1, and is further excellent in photosensitivity, mechanical properties and the like. The photosensitive resin composition according to claim 3 has the effect of the photosensitive resin composition according to claim 2, and is excellent in alkali developability. The photosensitive element according to claim 4 has excellent workability.

Claims (4)

[Claims] 1. A binder polymer having (A) a carboxyl group, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group in the molecule, and (C) a photoinitiator, wherein the (B) component is General formula (I) (In the formula, R ¹ represents a divalent organic group, and R ² represents a compound represented by the general formula (II): (In the formula, R ³ represents a hydrogen atom or a methyl group, X represents an alkylene oxide group, and n is an integer of 1 to 14) and a photosensitive resin composition containing the compound represented by the formula as an essential component. Stuff. 2. The photosensitive material according to claim 1, wherein the component (A) is soluble or swellable in an alkaline aqueous solution, has an acid value of 100 to 500, and has a weight average molecular weight of 20,000 to 300,000. Resin composition. 3. The use ratio of the component (A), the component (B) and the component (C) is such that the total amount of the component (A) and the component (B) is 100.
40 to 80 parts by weight of the component (A), (B)
20 to 60 parts by weight of component and 0.1 to 20 of component (C)
The photosensitive resin composition according to claim 1 or 2, which is 3 parts by weight of the compound represented by the general formula (I) in the component (B). 4. A photosensitive element obtained by applying the photosensitive resin composition according to claim 1, 2 or 3 on a support and drying it.