JPS60225149A - Photosensitive resin composition - Google Patents

Abstract

PURPOSE:To obtain superior electroplating resistance, and tough film strength by incorporating ethylenically unsatd. compds. represented by formulae I, II, an org. halogenated compd., a film-forming property giving polymer, and a sensitizer and/or a sensitizer system capable of producing free radicals upon exposure to actinic rays. CONSTITUTION:It is preferable to use 0.5-10pts.wt. of the sensitizer and/or the sensitizer system capable of producing free radicals upon exposure to actinic rays, and 0.2-10pts.wt. of the org. halogenated compd. per 100pts.wt. of the film-forming polymer and the ethylenically unsatd. compds. presented by formulae I and II in which R<1>, R<2> are each H or methyl; m is an integer of 1 or 2; a, b are each an integer and a+b=6, R1 is H or methyl; and X is ethyl or hydroxymethyl. The ethylenically unsatd. compd. represented by formula I has 6 functional groups, and high cross-linking density after light irradiation, and since it has many radically polymerizable unsatd. groups in one molecule, photoreaction speed is high. The ethylenically unsatd. compd. represented by the formula IIis hydrophobc, and extremely low in affinity to an electroplating soln.. The use of the combination of both said compds. can enhance resistance to plating solns., especially, pyrophosphoric acid, remarkably.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is particularly suitable for use as a photosensitive resin composition, more specifically as an etching resist or plating resist used in the production of printed wiring boards, precision processing of metals, etc. The present invention relates to a photosensitive resin composition having excellent adhesion, workability, or high sensitivity.

(Prior art) 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: tenting and plating. 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 Vi, copper is deposited in the through-hole by electroplating. , protect with solder plating, and remove 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. I
In particular, as a method for obtaining a highly sensitive photosensitive resin composition, it is common to increase the photosensitivity of the unsaturated compound used in a vehicle system in which one composition consists of a free radical generating initiator and an unsaturated compound. 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 1 nonaethylene glycol cyacrylate 1 note is suitable for this purpose, and these are commercially available products such as NK ester A-40 and A-9 from Shin Nakamura Chemical
It is sourced as G. In some cases, a polyethylene glycol structure may be introduced in addition to unsaturated compounds for the same purpose. Japanese Patent Publication No. 55-33801 discloses such an example.

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. This is particularly important for the durability of pyrophosphate steel plating, which has a high plating solution pH and is used at relatively high temperatures.

It is particularly bad and cannot be put to practical use. For this reason, in applications requiring plating resistance, 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;
Although it is difficult to obtain, many of the ones that are commercially available are not sticky.

When actually coating a film, the diluted medium must be used in large amounts at a rate of 1 lr-1, and it is difficult to say that it is personally useful.

(Object of the Invention) 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 object of the present invention is to provide a photosensitive resin composition that provides excellent plating resistance and strong film strength.

(Composition of the invention) The present invention is.

(A) Ethylenically unsorable compound represented by formula (1) Formula (1) (wherein R, 1, and R2 are hydrogen or methyl groups, mF'il is an integer of 2, and a and b are An integer with a+b=6.

a or b may be O) and formula ([ethylenic unsaturated compound represented by 11 (
CH2=CRICOOCH2-in-c-x formula (b);
(In the formula, R+?i is hydrogen or a methyl group, and X is an ethyl group or a hydroxymethyl group) CB+ Organic halogen compound □ FCI Film-imparting polymer and ■) A sensitizer capable of generating free radicals by actinic radiation and/or The present invention relates to a photosensitive resin composition containing a sensitizer system.

Thus, as ethylenically unsaturated compounds.

By using a combination of hexafunctional acrylate or methacrylate without a polyethylene glycol structure and trifunctional acrylate or methacrylate without a polyethylene glycol structure, it is possible to eliminate the conventional combination of trifunctional or less ethylenically unsaturated compounds. It is important to obtain plating resistance and strong film strength that were previously unavailable.

The ethylenically unsaturated compound represented by 2 (1), which is an acrylate or a methacrylate, is hexafunctional, and compared to conventionally used trifunctional or less functional compounds, the crosslinking density after light irradiation is high, and the tent strength is The one from Osakarai is 390
gf/3.2φ, but 460 gf/3.
The tent has a strength of 2φ or more. In addition, such hexafunctional ethylenically unsaturated compounds have a large number of radical monomerizable unsaturated groups in one molecule, so the photosensitivity is fast, and when compared at the same exposure amount, the sensitivity is 0.
5 to 1.0 steps higher. Moreover, if a photochromic agent is present at the same time, the hue after irradiation with light will be deep, and correction work during the manufacturing process of the printed wiring board will be easier, which is an advantage.

An ethylenically unsaturated compound represented by the formula (old).

When combined with a hexafunctional ethylenically unsaturated compound represented by the formula 11), the plating resistance is higher than that of the conventional one.

In particular, the resistance to copper plating is significantly improved.

This is because the structure of the ethylenically unsaturated compound represented by the formula (formerly) does not contain a J-thyl bond, so it is more hydrophobic than the polyethylene glycol structure, and has extremely low affinity with plating solutions. This is because the plating solution does not easily penetrate into the photosensitive resin composition even if it is immersed in the plating solution for a period of time.

Usually, at the beginning of the plating process, degreasing is performed to remove hand marks, oil, resist residue, etc. that have adhered to the substrate before the development process. This degreasing method includes neutral degreasing, acid degreasing,
There are alkaline degreasing methods, electrolytic degreasing methods, and among them, alkaline electrolytic degreasing solutions and phosphoric acid electrolytic degreasing solutions exhibit particularly strong permeability into photosensitive resin compositions. However, it is surprising that the photosensitive resin composition used in the combination of the present invention exhibits unprecedented resistance to these degreasing solutions.

In addition, 6-functional n-hyacrylate or methacrylate and 2
It has a higher crosslinking density after light irradiation than a combination with a subfunctional acrylate or methacrylate, so it has high sensitivity and strong film strength.

The values of m, a, and b of the ethylenically unsaturated compound represented by the formula (11) used in the present invention may be V!, as shown in Table 1, but the case shown in Table 1 (3) is preferable. °Earth.As this compound, Z2
゜2!2'-tetrakis(hydroxymethyl) -3,
An esterified product of a combination of 3'-oxydibrobanol and 6-hegisanolide adduct and acrylic acid is preferred.

An ethylenically unsaturated compound represented by the formula tn+, trimethylolpronosine triacrylate.

Trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaJ-lythritol trimethacrylate, etc. are used, but from the viewpoint of sensitivity, acrylate)? 11- It is desirable to use.

In addition to the ethylenically unsaturated compound in the photosensitive resin composition of the present invention, a conventionally known third component can be added, but from the viewpoint of high sensitivity, acrylate monomer or Preference is given to using methacrylate monomers. Examples include 1,6-hexanediol diacrylate, 2-bis(4-methacryloquinethoxyphenyl)propane, λ2-bis(4-acryloxyethoxyphenyl)furopane, cypentaerythritolbe71
71") V-1 etc. 0 polyvalent 7'"-'vOyt? ')71
.

Ephoxylates such as arylate or polymethacrylate, addition of trimethy A/propane trigly/dyl ether to acrylic acid or methacrylic ih + acrylic acid or methacrylic rib adduct of epoxy hammering of polyhahisphenol A epichlorohydrin thread 'Crylate.

Examples include low-molecular unsaturated polyesters such as a 1:1:2 condensate of hydrophthalic acid, neopenal glycol, and acrylic acid.

An amount of 10 to 45 n of an ethylenically unsaturated compound represented by formula (11) is added to the film property imparting polymer.

Ethylenically unsaturated compound represented by formula (■) from 10 to
It is preferable to use 45% by weight. If the amount of the ethylenically unsaturated compound represented by fil is less than 10% by weight, the sensitivity will be insufficient, and if the amount exceeds 45N, the plating resistance will tend to decrease. If the amount of the ethylenically unsaturated compound represented by formula (II) is less than 10% by weight, the sensitivity will be insufficient, and if it exceeds 45% by weight, the plating resistance will tend to deteriorate (+-).

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 compound is carbon tetrachloride.

Chloroporum, bromoform, l, l, 1-) IJ chloroethane, methylene bromide, methylene iodide, menalene chloride, carbon tetrabromide, iodoform, i, t, λ22-tetrapmoethane, pentabromoethane, tribromoacetophenono, Examples include bis-(tribromomethyl)sulfo/l tribromomethylphenylsulfone, vinyl chloride, and chlorinated melefin. Preferred are aliphatic halogen compounds having a weak carbon-halogen bond strength, particularly compounds in which two or more halogen atoms are bonded to the same carbon-halogen, especially organic bromine compounds. Organic chloride compounds containing tribromomethyl groups give more favorable results.

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

There are no particular restrictions, but high molecular weight products obtained by vinyl copolymerization are preferred. Vinyl polymerizable monomers used in the vinyl copolymer include methyl methacrylate, Boubourg methacrylate, and methacrylic #1a-ethyl? f-/l, lauryl methacrylate, ethyl acrylate, methylstyrene acrylate, vinyltoluene, N-vinylpyrrolidone, a-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
- Anthraquinones such as ethyl anthraquinone and t-butylanthraquinone, 2-chlorothioxanthone, benzoin ethyl ether, benzoin, sopropyl ether, benzyl, 2,4.5-triaryl imidazole dimer (lofin dimer), etc. One or more types may be used.

In the photosensitive resin composition of the present invention, the film property-imparting polymer, the ethylenically unsaturated compound represented by 2 (11), and the ethylenically unsaturated compound represented by formula (■) are added to 100 parts by weight of the ethylenically unsaturated compound represented by the formula (■). It is preferable to use 0.5 to 10!i parts of a sensitizer and/or sensitizer system capable of generating free radicals and 0.2 to 10 parts by weight of an organic halogen compound.The mixing order and mixing method of these materials There are no particular restrictions on such matters.

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

(Example) The present invention will be described in detail.

Example 1-a A film-like polymer was synthesized by the procedure described below.

A monomer mixed solution 4009 was prepared using the formulation K (7E) in Table 2. Next, a cooler and a thermometer 1 dropping device were connected to fc1.
Toluene 2509 and 150 g of the 400 g of the monomer solution weighed in Table 1 were placed in a 14 sulfur reaction flask, and the temperature was raised to 93° C. through a nitrogen stream. Then the remaining monomer 25
09. Toluene 1509, azobisisobutyronitrile o, and sog were mixed and the dissolved mixture was added dropwise over 3 hours.

After completion of the dropwise addition, the mixture was kept warm for another 7 hours. During this time, the temperature of the flask was maintained at 93°C. Next, dissolve 0.259 azobisisobutyronitrile in 75 g K1 of toluene and add 30
It was added dropwise over a period of minutes. After the dropwise addition, the mixture was kept warm for 4 hours and diluted with 75 g of ketoluene and 759 methyl enal ketone, respectively, as polymers (1) and (2). The properties of the obtained polymer were changed to 3 to 2.

More Table 2 (The numbers are heavy and the total amount is 400g) -b The following photosensitive resin compositions were blended according to the formulations shown in Table 4.

The following is my own 1-c (2) Photosensitive resin composition solutions of -1 to V-12.

Polyethylene terephthalate film (Lumira manufactured by Toshi@) with a thickness of 23 μm - film thickness after drying of 50 μm
The photosensitive element was coated and dried so as to have a thickness of m, 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 ScontiPride Buff Roll (manufactured by Sumitomo IJ-M), dried and cleaned with a copper-clad Wt plate (100 aunX
A test piece was obtained by laminating continuously on a conical surface of 200 mm) using a Hitachi high-temperature laminator. The lamination conditions are shown in Table 5.

Table 5-d A first-order failure test was conducted for each 1ζ test piece obtained in 1-c.

(1) Each test piece obtained in pyrophosphate copper plating resistance test 1-c was heated to 7 stages of an ultra-high pressure mercury lamp (HMW-6-N type manufactured by Oak Co., Ltd., 2KSv; Expose to light.

1, L, 1-1-II, 70u ethane-v”/
-to! T: Dust image (60 seconds, l 8'C, 1,5k
g/cm2).

The obtained base plate 6 was plated under 7I plate conditions,
Visually check the penetration state of the plating solution near the resist line.
Calculated by zone angle and refresh.

Margin below The evaluation criteria are shown in 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 in 7 stages using a 21-stage stencil printer.1. Develop with i-trichloroethane. As shown in FIG. 1, the through holes 3 are tented with the cured photosensitive layer 2. Next, as shown in FIG.
Push the tent part at 5 rim/min, increase the number of carts, and measure the load when the tent breaks,
#Strength and 17. 4 is a copper-clad laminate.

(3) Sensitivity test The specimen obtained at Knee ○ was exposed to light at 60 mJ or less using an ultra-high pressure mercury lamp through a negative equipped with a 21-stage stainless steel notebook. After standing for 30 minutes, the polyethylene terephthalate film was peeled off, developed with 1,1° 1-trichloroethane, and the number of cure stages of the stencil tablet was read. The larger the number, the higher the sensitivity.

Table 8 shows the experimental results for FIL (21,+3). 4
．． J, a trap as shown in Table 8 below - DPCA in H.
60 and A-TMPT (V-51 or A-TMM-3L
(V-6) shows better results in both birophosphate copper plating resistance 9M strength and sensitivity than the others.

[Brief explanation of the drawing]

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 3... Through hole 4... Copper clad laminate agent Patent attorney Kunihiko Wakabayashi 1 mouth

Claims (1)

[Claims] 1. (A) Ethylenically unsaturated compound represented by the formula (1+) (where Bl, H, 2 are hydrogen or methyl groups 1m is an integer of 1 or 2, a, b are a+b is an integer such that = 6.a and b may be O) and an ethylenically unsaturated compound represented by 2 (El) (
CHz =CR+ C00CH2(C-X Formula ([11
(In the formula, R1 is hydrogen or a methyl group; A photosensitive resin composition comprising a sensitizer and/or a sensitizer system.
2. The photosensitive resin composition according to claim 1, containing 10 to 45% by weight of the ethylenically unsaturated compound represented by (). 3. The ethylenically unsaturated compound represented by formula (1) is
λz Z/ 2/-tetrakis(hydroxymethyl)-
It is an esterified product of a condensate of 3,3'-oxydiglobanol and 6-hexanolide adduct and acrylic acid, and 1
3. The photosensitive resin composition according to claim 1 or 2, wherein the ethylenically unsaturated compound represented by formula (Il) is an acrylate. 4. Claim 1, wherein the organic-logen compound is an organic-logen compound having a tribromomethyl group;
The photosensitive resin composition according to item 2 or 3.