JPS60225841A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain superior close adhesion, superior operation efficiency, and high sensitivity as a resist material by incorporating a specified ethylenically unsatd. compd., an org. halogenated compd., a film-forming polymer, and a sensitizer. CONSTITUTION:The resist material contains ethylenically unsatd. polymers represented by formulae I and II, the org. halogenated compd., the film forming polymer, and the sensitizer or a sensitizer system capable of releasing free radicals upon exposure to actinic rays. In formula I, R<1>, R<2> is H or methyl; m is an integer of 1 or 2; (a), (b) are an integer and a+b=6, and may be 0. In formula II, Z is phenyl or a substd. phenyl; R<1> is 1-3C alkylene; R<2> is H or methyl; R<3> is H, methyl, ethyl, CH2C, or CH2Br. Each of the compds. of formulae I and IIis used in an amt. of 10-45wt% to the film-forming polymer. It is preferable to use a combination of an ester formed by acrylic acid and a condensation product of 2,2,2',2'-tetraquis(hydroxymethyl)-3,3'-oxydipropanol and 6-hexanolide, as the compd. of formula I ; and gamma-chloro-beta-hydroxypropyl-beta'-methacryloyloxyethyl-o-phthalate, as the compd. of formula II, and to use a compd. having -CBr3 as the org. halogenated compd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a photosensitive resin composition, more specifically, an etching resist or a plating resist used in the production of printed wiring boards, metal precision processing, etc., which has particularly excellent adhesion and workability. The present invention relates to a photosensitive resin composition having high sensitivity.

In the fields of printed wiring board manufacturing, metal precision processing, etc.
Chemical 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 using an electrical method. As a photosensitive element, one in which a photosensitive resin composition is laminated on a support is widely used.

Conventionally, there are two methods for manufacturing printed wiring boards: a tenting method and a plating method. In the tenting method, the copper through-hole for mounting the chip is protected with a resist, and then an electric circuit is formed through etching and resist peeling, whereas in the plating method, copper is deposited in the through-hole by electroplating. , protect with solder plating, and remove the resist.

This is a method of forming electric circuits by etching. Many printed wiring board manufacturers use this method depending on the application. Therefore, the photosensitive resin composition used is required to have sufficient film strength to withstand the spray pressure of the developer and water washing, and sufficient chemical resistance to withstand long-term immersion in the plating solution.

Conventional photosensitive resin compositions, as disclosed in Japanese Patent Publication No. 45-28063, use one or more monofunctional or more functional acrylates or methacrylates as ethylenically unsaturated compounds.

Good sensitivity, resolution, and adhesion can be obtained.

In particular, as a method for obtaining a highly sensitive photosensitive resin composition, in a polymerization system in which the composition consists of a free radical generating initiator and an unsaturated compound, it is common to increase the photosensitivity of the unsaturated compound used therein. be. Although various unsaturated compounds have been studied for this purpose, polyacrylates of polyhydric alcohols are widely used. Among these, acrylates having a polyether bond, particularly a polyethylene glycol structure, are particularly useful as highly sensitive acrylates. Tetraethylene glycol diacrylate, nonaethylene glycol diacrylate, etc. are suitable for this purpose, and these are commercially available products such as Shin Nakamura Kagaku, 9, NK Ester A-40, A.
-9G. In some cases, polyethylene glycol structures may be introduced in addition to unsaturated compounds for the same purpose. Such an example is shown in Japanese Patent Publication No. 55-33801.

However, although compounds such as acrylates having such a polyethylene glycol structure are useful for improving the sensitivity of photosensitive resin compositions and photosensitive elements using the same, since the polyethylene glycol structure is hydrophilic, they are difficult to use for plating. It has the disadvantage that it has a strong affinity with liquids and reduces plating resistance. In particular, the durability of birophosphate copper plating, which is used at relatively high temperatures due to the high pH of the plating solution, is important.

It is particularly bad and cannot be put to practical use. For this reason, in applications where plating resistance is required, the amount of compounds such as acrylates having such a polyethylene glycol structure to be used is limited, resulting in a corresponding decrease in photosensitivity.

On the other hand, as the ethylenically unsaturated compound in conventional photosensitive resin compositions, trifunctional compounds have been used for the purpose of increasing the photosensitive speed and increasing the crosslinking density after light irradiation. However, even if one or more trifunctional compounds are used,
The cross-linking density is not sufficient and the through-hole tent is torn.
This method has the disadvantage that product defects such as chipping and through-hole etching occur. Therefore, there has been a demand for using a tetrafunctional or higher functional compound as the ethylenically unsaturated compound and further increasing the crosslinking density after light irradiation to increase the film strength.

However, the number of tetrafunctional or higher ethylenically unsaturated compounds commercially available for industrial use is limited, and not only are they difficult to obtain, but many of the commercially available compounds have high viscosity.

When actually coating a film, a large amount of diluting solvent must be used, and it is difficult to say that it is industrially useful.

The present inventors have conducted repeated research in order to eliminate the above-mentioned drawbacks, and as a result, have arrived at two inventions.

The present invention is.

Ethylenically unsaturated compound formula (I) represented by CAl 2 (Il) (wherein Bt, R2 is hydrogen or a methyl group, 9m is an integer of 1 or 2, a, b are integers such that a-1-, b=6 Yes.

a or b may be O) and an ethylenically unsaturated compound represented by formula [11] (
In the formula, 2 is a phenyl group or substituted phenyl group, R1 is an alkylene group having 1 to 3 carbon atoms, R2 is hydrogen or tl-thyl group, B
S is hydrogen, methyl group, ethyl group, or CHtX;
is chlorine or bromine) (Bl organic/-rogen compound (C) film-imparting polymer and (DJ) containing a sensitizer and/or sensitizer system capable of generating free radicals by actinic radiation. The present invention relates to a photosensitive resin composition.

Thus, as ethylenically unsaturated compounds.

By using a combination of hexafunctional acrylate or methacrylate that does not have a polyethylene glycol structure and monofunctional acrylate or methacrylate that does not have a polyethylene glycol structure, it is possible to eliminate the conventional combination of trifunctional or less ethylenically unsaturated compounds. It is possible to obtain plating resistance and strong film strength that were previously unavailable.

The acrylate or methacrylate represented by formula (11) is hexafunctional, and when compared with conventionally used trifunctional or less functional ones, the crosslinking density after light irradiation is higher, and the tent strength of the conventional one is a9ogf/3. 2φ, it now has a tent strength of 460 gf/3.2φ or more.In addition, such hexafunctional ethylenically unsaturated compounds contain radically polymerizable unsaturated compounds in one molecule. Because it has a large number of saturated groups, the photosensitivity is fast, and when compared with the same exposure amount, the sensitivity is 0.5 to 1.0 steps higher.Also, if a photochromic agent is present at the same time, the It has a dark hue and has the advantage of facilitating correction work during the manufacturing process of printed wiring boards.

As the substituted phenyl group, a phenyl group substituted with an alkyl group, an ether group, an ester group, a hydroxyl group, a carboxyl group, etc. is used.

In the acrylate or methacrylate represented by formula (II), when Z is a phenyl group or a substituted phenyl group, plating resistance, particularly resistance to copper pyrolic acid plating, which has not been seen in the past, is significantly improved. This is because the phenyl group or substituted phenyl group is more hydrophobic than the polyethylene glycol structure, and has extremely low affinity with the plating solution, so even if immersed in the plating solution for a long time, the plating solution will not react with the photosensitive resin composition. This is due to the fact that it is difficult to penetrate inside. On the other hand, such phenyl groups or substituted phenyl groups have strong resistance to chlorinated solvent developers, so they prevent the developer from penetrating into the resist, improve the adhesion of the resist, and prevent the penetration of plating solutions. It is presumed that this is due to prevention. However, since such monofunctional acrylates or methacrylates have a very slow photosensitivity, they can only be used in combination with trifunctional or higher functional acrylates or methacrylates to obtain a photosensitivity sufficient for practical use.

The values of m, a, and b of the ethylenically unsaturated compound represented by the formula (Il) used in the present invention may be as shown in Table 1, but the values shown in Table 1 (3) are preferable.

In addition, as the ethylenically unsaturated compound represented by the formula (If), methacrylate is more preferable than acrylate from the viewpoint of water resistance, and γ-chloroβ-hydroxypropyl-β′-methacryloyl (or acryloyl) oxyester-〇 - Phthalate is preferred.

In addition to the ethylenically unsaturated compound in the photosensitive resin composition of the present invention, conventionally known third components can be added and used, but in terms of high sensitivity, acrylate monomers Alternatively, the use of methacrylate monomers is preferred. For example, trimethylolpropane triacrylate, pentaerythritol triacrylate, 1.
6-hexanediol diacrylate, 2,2-bis(
Polyacrylates or polymethacrylates of polyhydric alcohols such as 4-methacryloxyethoxyphenyl)pronokun, 2-bis(4-acryloxyethoxyphenyl)propane, dipentaherythritol pentaacrylate, trimethylolpropane trimethacrylate, trimethyl Epoxy acrylates such as adducts of propane triglycidyl ether with acrylic acid or methacrylic acid, acrylic acid or methacrylic acid adducts of bisphenol A epichlorohydrin-based epoxy resins, phthalic anhydride-
Examples include low-molecular unsaturated polyesters such as a 1:1:2 condensate of neopentyl glycol-acrylic acid.

The amount of the ethylenically unsaturated compound represented by formula (1) is 10 to 45% by weight based on the film properties imparting polymer.

The ethylenically unsaturated compound represented by formula (I) is 10 to
It is preferable to use 45% by weight. If the amount of the ethylenically unsaturated compound represented by the formula (Il) is less than 10% by weight, the sensitivity will be insufficient, and if it exceeds 45% by weight, the plating resistance will tend to decrease.The ethylenically unsaturated compound represented by the formula (It) If it is less than 10% by weight, the plating resistance will be insufficient, and if it exceeds 45% by weight, it will tend to cause a decrease in sensitivity.

The organic halogen compound is preferably one that easily releases halogen radicals by actinic light or one that easily releases halogen radicals by chain transfer.

An example of an organic halogen compound is carbon tetrachloride.

Chloroform, bromoform, LLI-1 chloroethane, methylene bromide, methylene iodide/, methylene chloride, carbon tetrabromide, iodoform, 1,1,2.2=tetrabromoethane, pentabromoethane, tribromoacetophenone, bis- Examples include (tribromomethyl)sulfone, tribromomethylphenylsulfone, vinyl chloride, chlorinated olefins, etc.Carbon-)・Aliphatic compounds with weak rogen bond strength...Rogen compounds, especially two atoms on the same carbon Organic bromine compounds, which are different from the compounds to which the above-mentioned nitrogen atoms are bonded, are preferable. Organic halogen compounds having a tribromomethyl group give more favorable results.

The film properties imparting polymer used in the present invention is as follows.

Although there are no particular limitations, a polymer obtained by Vitel copolymerization is preferred. Vinyl polymerizable monomers used in vinyl copolymers include methyl methacrylate, butyl methacrylate, α-ethylhexyl methacrylate, lauryl methacrylate, ethyl acrylate, methylstyrene acrylate, vinyltoluene, and N-vinylpyrrolidone. ,α−
Methylstyrene, α-hydroxyethyl methacrylate.

2-hydroxyethyl acrylate, acrylamide,
Acrylonitrile, dimethylaminoethyl methacrylate, dimethylaminoethyl acrylate, etc. are used.

Furthermore, there are no restrictions on the sensitizer and sensitizer system capable of generating free radicals by actinic rays in the present invention, and conventionally known ones can be used. For example, benzophenone, 4.4'-dimethylaminobenzophenone, 4.4'-diethylaminobenzophenone, 4.4
'-Dichlorobenzophenone and other benzophenones, 2
- Anthraquino such as ethyl anthraquinone and t-butylanthraquinone: yfR, 2-chlorothioxanthone,
One or more of benzoin ethyl ether, benzoin isopropyl ether, benzyl, 2,4.5-)lyarylimidazole dimer (lophine dimer), etc. are used.

In the photosensitive resin composition of the present invention, the film property-imparting polymer, the ethylenically unsaturated compound represented by formula (1), and the ethylenically unsaturated compound represented by formula (Ill) are 100 parts by weight by actinic radiation. Zero sensitizers and/or sensitizer systems that can generate free radicals
．． 5 to 10 parts by weight, 0.2 to 10 parts by weight of organic halogen compound
It is preferable to use heavy background. There are no particular restrictions on the mixing order, mixing method, etc. of these materials.

Note that dyes, plasticizers, pigments, flame retardants, stabilizers, etc. can also be added to the photosensitive resin composition of the present invention, if necessary. It is also possible to use an adhesion imparting agent.

The present invention will be described in detail.

Example 1-a A cyfilm-imparting polymer was synthesized by the procedure described below.

400 g of a monomer mixed solution was prepared according to the formulation in Table 2. Next, a cooler and a thermometer 1 dripping device were connected! 4
Toluene 2509 and 150 g of each of the 4009 monomer solutions weighed in Table 1 were placed in a Tulo reaction flask, and the temperature was raised to 93° C. through a nitrogen stream. Then the remaining monomer 2509
．． ) toluene 1509, azobisisobutyronitrile 0.
509 was mixed and the dissolved solution was added dropwise over 3 hours.

After the completion of the dropping, the pages were kept warm for 7 hours. During this time, the temperature of the flask was maintained at 93°C. Next, dissolve 0.259 of azobisin butyronitrile in 759 of toluene and add 30
I dripped it in minutes. After the dropwise addition, the mixture was kept warm for 4 hours and diluted with 75 g of toluene and 759 g of methyl ethyl ketone to give polymers i1) and +2>, respectively. Table 3 shows the properties of the obtained polymer.

Table 2 Table 3 -b The following photosensitive resin compositions were blended according to the formulations shown in Table 4.

*1 Trimethylolpropane triacrylate manufactured by Shin Nakamura Chemical *2 Tetraethylene glycol diacrylate manufactured by Shin Nakamura Chemical *3 Nippon Kayaku H#! &ar2'-tetrakis(hydroxymethyl) -3,3'-oxydibrobanol and 6-hexanolide adduct condensate and esterified product of acrylic acid *4 Osaka Organic Chemical Industry ■ γ-chloro β-hydroxypropyl- β'-Methacryloyloxyester-〇-phthalate *5 Manufactured by Shin-Nakamura Chemical ■ Trimethylolpropane trimethacrylate *6 Manufactured by Kawaro Chemical Industry ■ 2,2'-methylenebis(4-
ethyl-6-t-butylated phenol)/;I-1/-J
a In Table 4, V-5 and V-9 are examples of the present invention, and the others are comparative examples.

-c photosensitive resin composition solutions of vi to V-12.

After drying, the film thickness was 50 μm on a polyethylene terephthalate film having a thickness of 23 μm (Lumi 5-' manufactured by Bunshishi ■).
The photosensitive element was coated and dried, and then covered with a polyethylene film having a thickness of 35 μm to obtain a photosensitive element. While peeling off the polyethylene film from the obtained photosensitive element, the photosensitive layer surface was polished with a Scotchprite Buff Roll (manufactured by Jusumu IJ-M), and a copper-clad laminate (100 mm x 200 mm) that had been dried and cleaned was polished. A test piece was obtained by continuously laminating fc on a copper surface using a Hitachi high-temperature laminator. The lamination conditions are shown in Table 5.

Table 5 *Air pressure ct The following test was conducted for each test piece obtained in 1-c.

(1) Pyrophosphate copper plating resistance test Each test piece obtained in 1-c was heated to form 7 steps of a 21 step tablet using an ultra-high pressure mercury lamp (HMW-6-N type, 21@ manufactured by Oak Co., Ltd.). and developed with a 1°1.1-trichloroethane shower (60 seconds, 18°C).
, 1.5 kg/cm2).

The obtained substrate was plated under the plating conditions shown in Table 6, and the evaluation criteria for the penetration state of the plating solution near the resist line were shown in Table 7.
Shown below.

Table 7 (2) Film strength test Photosensitive elements were laminated on a through-hole copper-clad laminate with a diameter of 3.2 mm under the conditions shown in Table 5, and exposed to light using a 21-step tablet in 7 steps i, i, Develop with 1-trichloroethane shower. As shown in FIG. 1, the through holes 3 are tented with the cured photosensitive layer 2. Next, as shown in Fig. 1, a needle 1 with a diameter of 2 m + n is inserted.
Push the tent part at 5 WIm/min and increase the load. 4 is a copper-clad laminate.

The load at which the tent ruptured was measured and was defined as membrane strength.

(3) Sensitivity test The test piece obtained in 1-8C was exposed to light using an ultra-high pressure mercury lamp at 60 mJ/an'' through a negative equipped with a 21-step step tablet. After being left for 30 minutes, a polyethylene terephthalate film was exposed. wo peel 11111 L, 1
．． It was developed with a 1.1-trichloroethane shower, and the number of curing steps on the step tablet was read. The larger the number,
Indicates high sensitivity.

The experimental results for (1), (2), and (31) are shown in Table 8.

As is clear from Table 8, the above DPCA-60 and MEC
The system in combination with HPP shows better results in terms of birophosphate copper plating resistance, film strength, and sensitivity than the others.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the membrane strength testing method performed in the examples. Explanation of symbols 1... Needle 2... Hardened photosensitive layer

Claims (1)

[Claims] Ethylenically unsaturated compound formula (I) represented by formula (1) (in the formula, ratio 1.R2 is hydrogen or a methyl group, 9m is an integer of 1 or 2, and a and b are integers of 1 or 2. It must be an integer such that a -4-b = 6. a or b may be 0) and an ethylenically unsaturated compound represented by formula (II) (
In the formula, 2 is a phenyl group or a substituted phenyl group, H and i are an alkylene group having 1 to 3 carbon atoms, and R2 is hydrogen or a methyl group.
Bs is hydrogen, methyl group, ethyl group or CHgX,
X is chlorine or bromine. Resin composition. 2. 9 Formula II
10 to 45 ethylenically unsaturated compounds represented by I)
The photosensitive resin composition according to claim 1, expressed as % by weight. 3. The ethylenically unsaturated compound represented by formula (1) is z
z2: An esterified product of a condensate of f-tetrakis(hydroxymethyl)-he3'oxydibrobanol and a 6-hexanolide adduct and acrylic acid, 91 formula (II)
The ethylenically unsaturated compound represented by r-chloro-β
Hydroxyglobil-I methacryloyloxyethyl-
The photosensitive resin composition according to claim 1 or 2, which is 〇-phthalate. 4. Claims 1 and 2, wherein the organic halogen compound is an organic halogen compound having a tribromomethyl group.
The photosensitive resin composition according to item 1 or item 3.