JPH0756334A - Photosensitive resin composition and photosensitive element using the same - Google Patents

Abstract

PURPOSE:To provide a photosensitive resin compsn. excellent in adhesion, tent strength and peelability. CONSTITUTION:This photosensitive resin compsn. contains a polymer binder (A) having carboxyl groups, a photopolymn. initiator (B) and a photopolymerizable compd. (C) having at least one polymerizable ethylenically unsatd. bond in one molecule and the component C contains a compd. represented by the general formula [where (n) is an integer of 3-8] as an essential component. This photosensitive element uses this photosensitive resin compsn.

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,
It is known to use a photosensitive resin composition and a photosensitive element using the same as a resist material when an electric method is used. As the photosensitive element, one in which a photosensitive resin composition is laminated on a support is widely used.

This photosensitive resin composition is one which is cured by light and whose uncured portion is dissolved by an aqueous alkaline solution such as sodium carbonate. The photosensitive resin composition which is soluble in this alkaline aqueous solution contains a polymer having a group capable of dissolving in a water / alkaline medium such as carboxylic acid, carboxylic acid anhydride, sulfonic acid, phenolic or alcoholic hydroxyl group, or Copolymers are used (Japanese Patent Publication No. 35-
No. 14065, Japanese Patent Publication No. 39-1112, etc.).
However, with these compositions, it is not possible to produce a highly accurate relief image currently required for a printed wiring board, and it is not put to practical use.

Japanese Patent Publication No. 58-12577 discloses adhesion to flexible metal, cold flow of resist when a photosensitive element is stored in a roll or leaching from the end (cold flow). Although a composition aiming at lowering the edge fusion) has been proposed, since the long-chain methacrylate is copolymerized, the peeling time is long, and when the solder is peeled with an alkaline aqueous solution, the solder is There are problems such as falling off.

Japanese Patent Publication No. 1-36924 discloses a photosensitive element as an excellent etching or plating resist and having a low cold flow property. However, since these resin compositions use a copolymer having a high water absorption rate in order to obtain fast developability and releasability, the photo-cured portion also swells, and there are problems such as tent breakage and line jaggedness. .

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks, obtains excellent adhesiveness, tent strength, and releasability, and is a photosensitive resin composition capable of forming a highly accurate relief image. And a photosensitive element using the same.

[0007]

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

[Chemical 2] The present invention relates to a photosensitive resin composition containing a compound represented by the formula (n represents an integer of 3 to 8) as an essential component and a photosensitive element using the same.

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 dimer 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.

Among the photopolymerizable compounds having at least one polymerizable ethylenic unsaturated bond used as the component (C) in the present invention, the compound represented by the general formula (I) contained as an essential component is For example, CD-50
2 (n is 3 in the general formula (I), manufactured by Somar, trade name),
SR-9035 (n is 5 in the general formula (I), manufactured by Somar Corporation), SR-415 (n is 7 in the general formula (I),
The product name manufactured by Somar Co., Ltd. is used.

As the component (C), a compound other than the compound represented by the general formula (I) which is an essential component,
For example, polyethylene glycol di (meth) acrylate (having 2 to 14 ethylene groups), trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetra Methylol methane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate (the number of propylene groups is 2
14), dipentaerythritol penta (meta)
Acrylate, dipentaerythritol hexa (meth)
Bisphenol A, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol such as acrylate
Bisphenol A dioxyethylene di (meth), such as dioxyethylene di (meth) acrylate, bisphenol A trioxyethylene di (meth) acrylate, bisphenol A decaoxyethylene di (meth) acrylate
Compounds obtained by adding α, β-unsaturated carboxylic acid to glycidyl group-containing compounds such as acrylate, trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether acrylate, and polyvalent carboxylic acids such as phthalic anhydride And an esterification product of a substance having a hydroxyl group and an ethylenically unsaturated group such as β-hydroxyethyl (meth) acrylate, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, Examples thereof include alkyl esters of (meth) acrylic acid such as (meth) acrylic acid 2-ethylhexyl ester.

In the present invention, the compounding amount of the component (A) is
It is preferable that the amount is in the range of 40 to 80 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (C). 40
If it is less than 1 part by weight, the photocured product tends to be brittle, and when used as a photosensitive film, the coating property tends to be poor.
If it exceeds 0 parts by weight, the sensitivity tends to be insufficient.

The blending amount of the component (C) is the same as that of the component (A).
And 20 to 6 per 100 parts by weight of the total amount of the component (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 amount of the monomer represented by the general formula (I), which is an essential component in the component (C), is 10
It is preferably 10 to 100 parts by weight with respect to 0 parts by weight. If the amount is less than 10 parts by weight, the peeling time tends to be long.

In the general formula (I), n is an integer of 3-8. When n exceeds 8, the tent strength is poor. Further, when n is less than 3, the peeling time becomes long.

The amount of the photopolymerization initiator component (B) is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the total amount of the components (A) and (C). 0.
If it is less than 1 part by weight, the sensitivity tends to be insufficient, and
If the amount is more than parts by weight, absorption on the surface of the composition during exposure tends to increase, and internal photocuring tends to be insufficient.

Dyes, color formers, plasticizers, pigments, flame retardants, stabilizers, adhesion promoters and the like 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.

After the exposure, if a polymer film or the like is present on the photosensitive layer after exposure, it is removed and then an alkaline aqueous solution is used, for example, spraying, rocking dipping, brushing, scrubbing, 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 between 9 and 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.

[0026]

EXAMPLES Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the invention. Examples 1-2 and Comparative Examples 1-3 Methacrylic acid / methyl methacrylate / ethyl acrylate / ethyl methacrylate (polymerization ratio 22/45/27/6
(Weight ratio), weight average molecular weight 110,000) 40% by weight methyl cellosolve / toluene (weight ratio 6/4) solution 150 g
(Solid content 60 g) (component (A)), tribromomethylphenyl sulfone 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 ((B) component) ) And 0.2 g of N, N'-tetraethyl-4,4'-diaminobenzophenone (component (B)) were 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 resulting copper-clad laminate to 80 ° C. The resin composition layer was laminated while being heated to 120 ° C.

Next, using an exposing machine (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,
It shows that the photosensitivity is high.

Another test piece was exposed at 60 mJ / cm ² , the polyethylene terephthalate film was removed, and a cross cut test (JIS K-5400) was conducted. Also, 5 cm x
After exposing a 5 cm test piece at 60 mJ / cm ² and developing it for 60 seconds, 5
It was immersed in 3 wt% NaOH heated to 0 ° C., the time for peeling the resist was measured, and the size of the peeled piece was also measured.

Further, exposure and development were performed in the same manner as above using a negative of 100 μm line & space, and a cupric chloride etching solution was sprayed for 60 seconds at a spray pressure of 3 kgf / cm ² by a spray etching apparatus made by Sankei, and tested. The piece was etched, the resist was peeled off, and the creases on the line were observed.

Further, the sample after the cross-cut test was etched, and the penetration of the etching liquid in the cut portion was observed.

Next, a laminate of the photosensitive resin composition was laminated on both sides of a substrate having 100 holes of 6 mm in diameter in a 1.6 mm-thick copper clad laminate, and exposed at 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 mm to measure the strength and elongation before breaking. The results are summarized in Table 1.

[0035]

[Table 1]

As is apparent from Table 1, by incorporating the component (C) containing the compound represented by the general formula (I) as an essential component, the adhesiveness is excellent, the tent strength is strong, the peeling time is short, and the peeling is short. A photosensitive resin composition having a small piece size can be obtained.

[0037]

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

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H05K 3/18 D 7511-4E

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 bond in the molecule, The component (C) has the general formula (I): A photosensitive resin composition containing a compound represented by the formula (n represents an integer of 3 to 8) as an essential component. 2. The content of the ethylenically unsaturated compound represented by formula (I) in the component (C) is 100% of the component (C).
The photosensitive resin composition according to claim 1, which is 10 to 100 parts by weight with respect to parts by weight. 3. The use ratio of components (A), (B) and (C) is 0 to 40 to 80 parts by weight of (A) (B) to 100 parts by weight of the total amount of (A) and (C). 1 to 20 parts by weight and (C) 20 to 60 parts by weight (provided that the total amount of (A) and (C) is 100 parts by weight). . 4. A photosensitive element obtained by applying the photosensitive resin composition according to claim 1, 2 or 3 onto a support and drying it.