JPH06194843A - Photosensitive resin composition and photosensitive film using that - Google Patents

Abstract

PURPOSE:To provide a photosensitive resin compsn. having good adhesion property with a substrate and to provide a photosensitive film using this compsn. so that peeling of a resist on a printed circuit board caused by contact of substrates during handling is prevented. CONSTITUTION:This photosensitive resin compsn. contains (a) polymer compd. having 20000-300000 weight average mol.wt. and carboxyl groups, (b) ethylenically unsatd. compd. and (c) photoinitiator which produces radicals by irradiation of active rays. This compsn. is soluble or swellable with an alkali soln. The ethylenically unsatd. compd. (b) contains an ethylenically unsatd. compd. having silicone groups as the essential compsn. This photosensitive resin compsn. is used to produce the photosensitive film.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A photosensitive resin composition and a photosensitive film having a photosensitive resin composition laminated on a support layer have been widely used as resists used in the production of printed wiring boards. Laminate the photosensitive layer side of the photosensitive film on the printed wiring board substrate that has been cleaned by polishing, etc., and then expose it with an actinic ray through a desired negative mask, then remove the support and unexposed area using an aqueous solution of sodium carbonate, etc. Is removed by development to form a resist image on the substrate.

To form the wiring, the resist is peeled off after etching with cupric chloride or the like, or after the resist is peeled off after copper plating and solder plating.
There are methods such as etching. The photosensitive film is also used as a solder resist when forming a resist on the wiring. In this case, the resist image is formed and then sufficiently cured by ultraviolet rays or heat.

[0004] These resist images may be peeled off from the substrate due to contact with another substrate or the like in the process and the handling thereafter, and become defective. to solve this problem,
It has been proposed to add a kind of chelating agent so that it adheres well to copper on the substrate and does not peel off in a cross-cut test (JP-A-53-702, etc.), but it is not sufficient. . In addition, ethylenically unsaturated compounds and polymer compounds have been investigated, but satisfactory ones have not been obtained.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a photosensitive resin composition and a photosensitive film using the same, which reduces the peeling of the resist from the substrate due to insufficient adhesion to the substrate, which has been a conventional problem. To do.

[0006]

[Means for Solving the Problems]

(A) Weight average molecular weight of 20,000 to 300,000
Which is soluble or swellable in an alkaline aqueous solution containing a polymer compound having a carboxyl group, (b) an ethylenically unsaturated compound, and (c) a photoinitiator capable of generating free radicals by actinic radiation In the resin composition,
(B) A photosensitive resin composition in which an ethylenically unsaturated compound contains an ethylenically unsaturated compound having a silicone group as an essential component, and a photosensitive film using the same.

The photosensitive resin composition of the present invention has a weight average molecular weight of 20,000 to 300,000 as the component (a).
It includes a polymer compound having 0 carboxyl groups.

Such a polymer compound preferably has a carboxyl group content of 15 to 50 mol%, and one or more of these can be used in combination. The polymer compound is preferably soluble or swellable in an alkaline aqueous solution, but may be any one as long as the photosensitive resin composition can be developed with the alkaline aqueous solution.

[0009] Usually, the polymer compound used is
A vinyl copolymer is preferable, and as the copolymerizable monomer used for the vinyl copolymer, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, ethyl acrylate, methyl acrylate, styrene can be used. , Α-methylstyrene, vinyltoluene, N-vinylpyrrolidone, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, acrylamide, acrylonitrile, methacrylonitrile,
Dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, acrylic acid, methacrylic acid, etc. are used. Further, a half ester of a styrene / maleic acid copolymer or the like is also used.

The compounding amount of the component (a) is preferably 40 to 80 parts by weight based on 100 parts by weight of the total amount of the components (a) and (b). When this amount is less than 40 parts by weight, the developability is deteriorated and the flexibility of the photosensitive resin composition layer is increased,
When the laminate is used, there is a possibility that exudation from the end face, that is, edge fusion or the like may occur, and if it exceeds 80 parts by weight, the photosensitivity may decrease.

Further, the photosensitive resin composition of the present invention is
As the component (b), an ethylenically unsaturated compound is contained as an essential component. This ethylenically unsaturated compound contains an ethylenically unsaturated compound having a silicone group as an essential component. The ethylenically unsaturated compound having a silicone group is not particularly limited, but those represented by the following general formula (I) are preferable.

[Chemical 2] [In the formula, R ₁ represents hydrogen or a methyl group, R ₂ represents a hydrogen atom, a group containing an acryloyl group or a group containing a methacryloyl group, and R ₃ represents an alkyl group having a C number of 1 to 3,
R ₄ represents an alkoxy group having a C number of 1 to 3, and n is 2 to 4
And k and m are each independently 1 to 3 and k + m = 3.
The compound represented by the general formula (I) is available as a silicone oligomer series manufactured by Shin-Nakamura Chemical Co., Ltd. (for example, trade names S-1 and S-1M are available).

The ethylenically unsaturated compound other than the ethylenically unsaturated compound having a silicone group represented by the general formula (I) is not particularly limited. Specific examples of such compounds include compounds obtained by adding α, β-unsaturated carboxylic acid to polyhydric alcohol, for example, tetraethylene glycol di (meth) acrylate [(meth) acrylate is methacrylate and acrylate. Means The same applies hereinafter], polyethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, polypropylene glycol (Meth) acrylate,
Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc .; Compounds obtained by adding α, β-unsaturated carboxylic acid to a glycidyl group-containing compound, for example, trimethylolpropane triglycidyl ether Triacrylate, bisphenol A diglycidyl ether di (meth) acrylate, etc .; substances having a polyvalent carboxylic acid (eg, phthalic anhydride) and a hydroxyl group and an ethylenically unsaturated group (eg, β-
Esterification product with hydroxyethyl (meth) acrylate; alkyl ester of acrylic acid or methacrylic acid, for example, (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth ) Acrylic acid 2-ethylhexyl ester or the like is used, and a urethane diacrylate compound obtained by reacting trimethylhexamethylene diisocyanate, a dihydric alcohol and a monoester of (meth) acrylic acid of a dihydric alcohol, bisphenol A,
Addition products of alkylene glycol and acrylic acid or methacrylic acid, β-phenoxyethoxyethyl acrylate and the like are also used.

The blending amount of the component (b) is preferably 30 to 60 parts by weight based on 100 parts by weight of the total amount of the components (a) and (b). If it is less than 30 parts by weight, sufficient curability may not be obtained, and if it exceeds 60 parts by weight, edge fusion and the like may occur. Of this,
The amount of the ethylenically unsaturated compound containing silicone is preferably 20 parts by weight or more based on 100 parts by weight of the total amount of the components (a) and (b). Below 20 parts by weight,
The effect of preventing peeling tends to be insufficient.

The photosensitive resin composition of the present invention contains as a component (c) a photoinitiator capable of generating free radicals by actinic radiation, as an essential component. Examples of the (c) photoinitiator that can be used include 4,4′-bis (dimethylamino) benzophenone [Michler's ketone], 4,4′-bis (diethylamino) benzophenone, dimethylaminobenzoic acid ethyl ester, diethylaminobenzoic acid. Examples thereof include ethyl ester, benzyl dimethyl ketal, dimethylaminobenzoic acid butyl ester, dimethylaminobenzoic acid isoamyl ester, benzophenone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and 2-propylthioxanthone. From the viewpoint of photosensitivity, the amount of the component (c) compounded is preferably 0.01 to 30 parts by weight, based on 100 parts by weight of the total amount of the components (a) and (b).

Dyes, pigments, plasticizers, stabilizers and the like may be added to the photosensitive resin composition of the present invention as needed.

The photosensitive resin composition of the present invention can be used as a photosensitive film 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 made of a material that cannot be removed or surface-treated. 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 the photosensitive film, first, the photosensitive resin composition containing the components (a) to (c) is uniformly dissolved in a solvent. The solvent may be a solvent that dissolves the photosensitive resin composition, for example, acetone, methyl ethyl ketone, a ketone solvent such as methyl isobutyl ketone,
An ether solvent such as methyl cellosolve and ethyl cellosolve, a chlorinated hydrocarbon solvent such as dichloromethane and chloroform, and an alcohol solvent such as methyl alcohol and ethyl alcohol are used. These solvents may be used alone or in combination of two or more.

Then, the photosensitive resin composition in the form of a solution is uniformly applied on the polymer film as the supporting film layer, and then the solvent is removed by heating and / or blowing with hot air to form a dry film. The thickness of the dry film is not particularly limited and is usually 10 to 100 μm, preferably 20 to 6
It is set to 0 μm.

The photosensitive film of the present invention composed of the two layers of the photosensitive layer and the polymer film thus obtained is wound in a roll form as it is or on the other surface of the photosensitive layer, which is further laminated with a protective film. Stored.

In producing a photoresist image using the photosensitive film of the present invention, when the protective film is present, after removing the protective film, it is cleaned by polishing while heating the photosensitive layer. It is laminated by pressing on the finished substrate.

The heating and pressure bonding of the photosensitive layer are usually 90 to 130.
The temperature is 3 ° C and the pressure is 3 kgf / cm ² , but these conditions are not particularly limited. Further, when processed as a solder mask, it is preferable to stack under a reduced pressure. Also,
Substrates may be preheated before lamination.

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, or the like 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 other than those described above is photographed. Flood light bulbs and sun lamps are also used.

After the exposure, if a polymer film 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. are known. By the method, the unexposed portion is removed and development is performed. 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 alkaline water-soluble pH 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.

When forming the wiring of the 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. 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 is used.

In the case of processing as a solder mask, it is completed by performing heat treatment at 80 ° C. to 200 ° C. and exposure with active light after development. Either the heat treatment or the exposure with the active light may be performed first, or each may be divided into several times.

[0026]

EXAMPLES Next, the present invention will be described in more detail by way of examples. "Parts" in the following examples means "parts by weight" unless otherwise specified.

Example 1 A solution (solution A) having the composition shown below was uniformly applied onto a polyethylene terephthalate film having a thickness of 20 μm by using the apparatus shown in FIG. 1, and a hot air convection dryer 7 at 100 ° C. was used.
The solvent was removed by drying for about 5 minutes. In FIG. 1, 1
Is a polyethylene terephthalate film feeding roll, 2, 3, 4, 9 and 10 are rolls, 5 is a knife, 6
Is a solution of the photosensitive resin composition, 8 is a polyethylene film feeding roll, and 11 is a photosensitive film winding roll. The thickness of the photosensitive layer after drying was about 50 μm.

[0028]

[Table 1]

Then, a polyethylene film was bonded as a protective film on the photosensitive layer using the apparatus shown in FIG. 1 to obtain a photosensitive film of the present invention.

Separately, the copper surface of a printed wiring board substrate (trade name MCL-E-61 manufactured by Hitachi Chemical Co., Ltd.), which is a glass epoxy material in which copper plates are laminated on both sides, is polished with Scotch Bright (3M Company). After polishing and cleaning with an abrasive brush, it was dried with an air stream. A laminator (model HLM-150, manufactured by Hitachi Chemical Co., Ltd.) is placed on this substrate (23 ° C.).
0) is used and the lamination temperature is 110 ° C and the lamination pressure is 3 kg / cm ²
Then, the photosensitive films were laminated.

Then, the sample obtained was charged with a Stouffer
Exposure was carried out at 100 mJ / cm ² using a 201B type exposure machine manufactured by Oak Manufacturing Co., Ltd. using a 1-step step tablet (negative of 30 to 300 μm resolution evaluation). After being left at room temperature for 30 minutes, development was performed.

The development was carried out for about 60 seconds by removing the polyethylene terephthalate film and then spraying a 1% by weight sodium carbonate aqueous solution at 30 ° C. Development was completed in about 1/2 of the developing tank, and the number of remaining step tablet stages was eight. A 60 μm linear line was resolved. Further, using a cutter knife, 11 pieces were made at intervals of 1 mm to make horizontal cuts, and then a peeling test (cross-cut test) was performed using cellophane tape manufactured by Sekisui Chemical. As a result, there was no place to peel, and 100
100 eyes (100/100) remained on the eyes, showing good adhesion. Next, a cupric chloride etching solution (an aqueous solution containing 200 g / 1 of cupric chloride and 200 g / 1 of hydrochloric acid) is added.
Heated to 0 ° C and spray-etching machine 2.
Etching was performed with a spray pressure of 5 kgf / cm ² . When this sample piece was stripped with a 2 wt% sodium hydroxide stripping solution at 50 ° C., the resist was stripped from the substrate,
It showed good peelability.

Table 2 shows the test results. Examples 2-3 and Comparative Examples 1-3 The ethylenically unsaturated compound S- in the formulation shown in Example 1
The compounds shown in Table 1 were used instead of 1M and BPE500, and the other compounds were blended in the same manner as in Example 1. Next, each resin composition was evaluated by the same process as in Example 1, and the results of the remaining step stage, the adhesiveness, the crosscutting property, and the peeling property are shown in Table 2.

[0034]

[Table 2]

* 1 S-1 = trade name of silicone oligomer manufactured by Shin-Nakamura Chemical Co., Ltd. In the general formula (I), R ₁ is H, R ₂ is H, R ₃ is CH ₃ , and R ₄ is OCH _3. , M
= 1, n = 2, k = 2 * 2 TMCH = 2,2,4-chilymethylhexamethylene-1,6-diisocyanate / 2-hydroxyethyl acrylate at a molar ratio of 1: 2, synthetic product * 3 A-TMPT = Trade name of trimethylolpropane triacrylate manufactured by Shin-Nakamura Chemical Co., Ltd.

As is clear from Table 2, when the photosensitive resin composition of the present invention is used, the cross-cut property is good and it is sufficiently adhered to the substrate.

Example 4 A solution having the following composition (solution B) was applied in the same manner as in Example 1 to prepare a photosensitive film having a photosensitive layer thickness of about 50 μm after drying.

[Table 3]

Then, 200 mJ after lamination as in Example 1.
Exposure was carried out at / cm ² and development was carried out for 100 seconds. Further, it was exposed to 35 mJ / cm ² with a high pressure mercury lamp and then heated at 150 ° C. for 30 minutes. Then, rosin flux MH-820
V (Tamura Kaken Co., Ltd.) was used for soldering at 260 ° C. for 10 seconds, and the solder heat resistance was examined. as a result,
No abnormalities were found in the resist. Further, a cross-cut test was conducted, and 100/100 showed good adhesion.

[0039]

EFFECTS OF THE INVENTION By using the photosensitive resin composition of the present invention and the photosensitive film using the same, it is possible to improve the adhesion to the substrate and prevent the peeling due to the mutual contact of the substrates.

[Brief description of drawings]

FIG. 1 is a system diagram of a photosensitive film manufacturing apparatus used in Examples.

[Explanation of symbols]

1 Polyethylene terephthalate film feeding roll 2, 3, 4, 9, 10 roll 5 Knife 6 Solution of photosensitive resin composition 7 Dryer 8 Polyethylene film feeding roll 11 Photosensitive film winding roll

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G03F 7/033 7/085 H01L 21/027 H05K 3/00 F 6921-4E

Claims (3)

[Claims] 1. (a) Weight average molecular weight of 20,000 to
Soluble or swollen in an alkaline aqueous solution containing a polymer compound having 300,000 carboxyl groups, (b) an ethylenically unsaturated compound, and (c) a photoinitiator capable of generating free radicals by actinic radiation In the possible photosensitive resin composition, the photosensitive resin composition in which (b) ethylenically unsaturated compound contains the ethylenically unsaturated compound which has a silicone group as an essential component. 2. The photosensitive resin composition according to claim 1, wherein the ethylenically unsaturated compound having a silicone group is a compound represented by formula (I). [Chemical 1] [In the formula, R ₁ represents hydrogen or a methyl group, R ₂ represents a hydrogen atom, a group containing an acryloyl group or a group containing a methacryloyl group, R ₃ represents an alkyl group having 1 to 3 carbon atoms, R _{3 4} represents an alkoxy group having 1 to 3 carbon atoms, n is 2 to 4, k and m are each independently 1 to 3 and k +
chosen such that m = 3] 3. A photosensitive film obtained by applying the photosensitive resin composition according to claim 1 or 2 onto a support and drying it.