JPS63144342A - Dry film photoresist - Google Patents

Abstract

PURPOSE:To obtain the titled photoresist which has a sufficient sensitivity and sticking property to a metal substrate, and an excellent anti-etching property by constituting the titled resist by a transparent high polymer film as a 1st and 3rd layers and a photosensitive layer contg. a specific component as a 2nd layer. CONSTITUTION:The titled photoresist is composed of the three layer laminate having flexibility. The 1st and 3rd layers are composed of the transparent high polymer film, and the 2nd layer is composed of the photosensitive layer contg. the high polymer having an acid value of 50-300 and a mol.wt. of 10,000-500,000, a monomer having two or more of ethylenic unsatd. double bonds in a molecule and capable of effecting an additional polymerization, an org. peracid ester compd. having a benzene or a benzophenone skelton in the molecule and at least one kind of org. dye compds. shown by formulas I-III wherein R1, R2, R3 and R5 are each 1-4C alkyl group, R4 is 1-4C alkylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to dry film photoresist K B4i3 used in printed circuit manufacturing. This invention relates to a dry film photon cyst used to directly draw circuit patterns without using a mask.

[Prior art]

Dry film photoresist is a printed circuit board, such as a copper clad laminate, by thermo-compression bonding of the dry film photoresist with the first I- removed, and after exposure to an ultraviolet light source with an intermediate mask of the circuit pattern, some remains. Therefore, by using this as an acid-resistant resist and etching the board with a Ji etchant, the desired printed circuit board can be obtained (Nobuyuki Hayashi, Makoto Kaji; Thermosetting resin,
6t1)14(i985)).

[Problem that the invention seeks to solve]

Printed circuit fabrication using dry film photoresist provides higher-density wiring than circuit patterns fabricated by screen printing, but requires an intermediate mask and one layer.
Since there is a polymer film layer between the optical layers, it is difficult to obtain a wiring pattern that is thinner than a certain limit, for example, 100 μm. Although there are examples of attempts to achieve this, there are limits to this as well, and furthermore, it is not a method that fully satisfies the requirements for printed circuit boards with a temperature higher than that of ICs.

Another problem is that in recent years, as wiring circuits have become more complex, computer-based circuit design systems, known in the industry as CAD or CAM, have come into use. After exposing the output to a silver halide film to create an intermediate mask, the film is brought into close contact with a dry film and exposed to ultraviolet light again.

If it is possible to directly output CAD onto a dry film resist in a short time without exploding the intermediate mask in the above process, the number of manufacturing steps for printed circuit boards can be greatly shortened, and the expensive This eliminates the need for a silver salt film, which is economically advantageous.

The best method used to solve the two major problems mentioned above is a system that uses the designed circuit pattern as a one-dimensional time-series signal and draws it directly onto the dry film resist at high speed using a narrowly focused laser beam. be. Laser beams are highly focused and can be scanned at high speed, making it possible to create circuit patterns with much higher density than conventional methods. This method can also be used to modify a portion of a circuit pattern, making it possible to process the process extremely quickly. The laser used here is, for example, an argon ion laser, a helium-neon laser, etc.
Although visible light total loss lasers such as , helium-cadmium lasers, and semiconductor lasers are suitable for equipment, dry film photoresists with sufficient sensitivity to cope with high-speed scanning exposure using such visible light lasers are the best in the industry. Despite strong demand, it has not been obtained to date.

The purpose of the present invention is to obtain a dry film photoresist that has a sufficient angle of 18 degrees for high-speed scanning exposure using a visible light laser and also has excellent adhesiveness to metal substrates and etching resistance. Ru.

[Means for solving problems]

The present invention consists of a flexible three-layer horizontal body, the first and third layers of which are flexible. The present invention provides a dry film photoresist having the following characteristics: '# is a transparent pigeon molecular film, and the second layer is a photosensitive layer containing the components (i) to (■) shown below. .

(i) An acid value of 50 to 300 and a molecular weight of 10,000 to
500,000 high molecular weight polymer (i1) A monomer having two or more addition-polymerizable ethylenic unsupported double Vj groups in the molecule F3- Has a benzene skeleton and a 71 ben/phenone skeleton in the preform Organic hyperester compound; ψR of the organic dye compound represented by the general formulas (i) to (i) (R+ represents an alkyl group having 1 to 4 carbon atoms) (Rs represents an alkyl group having 1 to 4 carbon atoms) (represents an alkyl group) used in the present invention (
i) Acid value 50-300, molecular weight 10000-5000
The high molecular weight polymer of 00 is a vinyl-based addition polymer and a polyester-based polymer.

Condensation type polymers such as polyurethane type and polyamide type 1 For example, (meth)acrylic acid, (meth)acrylic acid ester, maleic acid, fumaric acid, maleic acid ester, fumaric acid ester, ethylene glycol, styrene, acrylic acid, etc. 2) Copolymers of lyle, vinyl chloride, etc. are preferred.

If this acid value is less than 50, the solubility will be low in the weakly alkaline aqueous solution used as a developer in the development process after exposure, and the oxidation will be too high with a V thicker than 300. It will wash away from the board.

Examples of the (i1) addition-polymerizable ethylenically unsaturated monomer used in the present invention include polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and 1,3-butanediol di(meth)acrylate. Acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)7crylate, trimethylolpropane tri(meth)7acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate , polyester (meth)acrylates such as pentaerythritol tetra(meth)7-acrylate, epoxy (meth)acrylates, and urethane (meth)7-acrylates.

Song) Organic peracid ester compounds used in the present invention include:
Those with a 10-hour half-life temperature of 70C or higher are preferred, such as tert-butyl peroxybenzoate, tert-butyl peroxymethoxybenzonate, tert-butyl peroxynitobenzoate, tert-butyl peroxyethyl benzoate, phenyl isopropyl peroxy/shade. , ditert-butyl diberoxyin 7-talate, tri-tert-butyl-triberoxy trimellitate, tri-tert-butyl-triberoxy trimesinate, tetra-tert-butyl-triberoxypyromellitate, 2.
5-dimethyl-2,5-di(benzoylperoxy)hexane, 3.3'.

4.41-tetra-(tertiarybutylperothousandicarbonyl)benzophenone, 3.3',4.4'-tetra(tertiaryamylperoxycarbonyl)benzophenone, 3.3',4.4'-tetra( Examples include tertiary hexylberoxycarbonyl) benzophenone.

The (i■) organic dye compound used in the present invention is a merocyanine dye represented by the following formula (i), R,0 (R+ represents an alkyl carrier having 1 to 4 carbon atoms) and the following open formula and +ff1) formula. Thioxanthin dye shown in .

(Rs represents an alkyl group having 1 to 4 carbon atoms),
These organic dye compounds may be used alone or in combination of two or more, and any commercially available compounds may be used as appropriate.

The preferred blending ratio of each of the above components is (i) component 100it.
The beating component is 10 to 200 parts by weight, and the components 011) and (iv) are each 0.1 to 30 parts by weight based on the sunken part.

Furthermore, in addition to the above-mentioned components, 3 to 20 parts by weight of a plasticizer may be added to adjust the plasticity and brittleness of the photosensitive layer.

Examples of the plasticizer that can be used include digtylphthalate, glycerol triacetate, and trimethylolpropane)IJ acetate.

Additionally, 0.01 to 5 tfit parts of polymerized Q regular may be added to the photosensitive layer to improve the storage stability of the dry film photoresist. As the polymerization inhibitor +h II K, hydroquinone, hydroquinone 7-methyl ether, etc. which are commonly used can be used.

The photosensitive layer of the present invention is prepared by mixing the above-mentioned components in a suitable diluting solvent, coating the mixture on a polymer film, and then drying the mixture.

Examples of diluting solvents include isopropanol, methyl ethyl ketone, toluene, xylene, and cellosolve.

Examples of the polymer film used in the present invention include films of polyethylene, polyethylene terephthalate, polyvinyl chloride, polyester, etc., and the thickness thereof is 1
~200 μm is preferred.

The dry film photoresist of the present invention preferably uses a polyethylene film for the first layer, preferably uses a polyethylene film for the third layer, and has the above-mentioned photosensitive layer with a second layer having a thickness of 5 to 200 μm. They are arranged to form a laminate of three monks.

〔Effect of the invention〕

The dry film photon cyst of the present invention has high sensitivity, and upon irradiation with a visible light laser having a wavelength of 400 to 7001 cm, a photochemical reaction occurs within a short time to form a predetermined cured film. This cured film has sufficient acid resistance in the subsequent etching process, and can be finally removed using an alkaline aqueous solution, and has excellent performance as a photoresist.

〔Example〕

The present invention will be explained in more detail below with reference to Examples and comparisons. Note that ``Ko'' and ``Chi'' in the columns indicate parts by weight and heavy loading.

Actual example 1: Dry a photosensitive solution with the following composition on a 25 μm thick polyethylene terebutanate film, knead it to a kA thickness of 35 μm, and after drying, temporarily fabricate a 20 μm thick polyethylene film and make a dry film photo. It was used as a resist.

(i) Acrylic polymer (acid value 175) 100 parts 30
Part (lii) 3,3',4,4'-tetra(tertiarybutylberiocarbonyl)benzophenone 3 parts (i■)
Organic dye compound having the following structure: 1 part C2H50 0 Hydroquinone 0.1 part Q Improper Tool 200 parts After peeling off the polyethylene film layer, the obtained dry film resist was heat-compression bonded to a copper-clad horizontal laminate at 100 CVC. It became.

For exposure, an argon ion laser with an output of 200 fnW was used, and an oscillation line with a wavelength of 488 nm was irradiated with a beam diameter of 25 μf'r.
Scanning exposure was performed at a LK aperture and a speed of 5.5 m/see. After exposure, the polyethylene terephthalate film was peeled off, and spray development was performed with a 2% aqueous sodium carbonate solution at 30C for 1 minute.

The cured relief thus obtained was extremely clear and strong, and no damage occurred even when etched with a ferric chloride aqueous solution at 42 degrees Baumé. Part 1l
The cured relief was removed with an aqueous solution of 10% caustic soda to obtain a new printed circuit board.

Example 2 A dry film photoresist was produced using a photosensitive solution having the following composition in the same manner as in Actual Example 1.

0 acrylic polymer (acid value 260) Zoo part O trimethyl ρ-propane triacrylate)
40 parts O tetraethylene glycol cyacrylate
30 part o3, 3', 4.4'-
Tetra (tert-butylperoethylcarbonyl) Benzophenone 3 parts O Organic dye compound with the following structure 0, 8 parts O Hydroquinone 0.07 parts O Isopropanol 200 parts Methyl ethyl ketone 200 parts The resulting dry film photoresist After thermocompression bonding to a copper-clad laminate using the same method as in Example 1, the output was 300 fF! Using a W argon ion laser.

Focus the oscillation line with a wavelength of 488 nm to a beam diameter of 25 μm, and
．． High-speed scanning exposure was performed at a speed of 5 m/3ee. After scanning exposure, the polyethylene terephthalate film was peeled off and sprayed with 1 liter aqueous sodium carbonate solution at 30C for 1 minute.

Example 3 In Example 1, 3 parts of ditertiary butyl diperoxyisophthalate was used as the organic peracid ester compound, and 1.2 parts of the compound represented by the following structural formula was used as the organic dye compound. A dry film photoresist was prepared and thermocompression bonded to a horizontal copper-clad plate.

C4H3O Here, output 250ff! W argon ion laser
using an oscillation line with a wavelength of 488 nm and a beam diameter of 25 μm1
High-speed scanning exposure was performed at 7 apertures and a speed of 6.5 m/sec. 1′! After exposure, development was carried out in the same manner as in Example 1.

Example 4゜Production was carried out in the same manner as in Example 2 except that 4 parts of tritertiary butyl triperoxy trimellitate was used as the organic perester compound and 1 part of the compound represented by the following structural formula was used as the organic dye compound. A dry film photoresist was prepared and thermocompression bonded to a stretched laminate.

Here, using a fulgon ionizer with an output of 3 oomw, high-speed scanning exposure was performed at a speed of 4.2 m/sec with a beam diameter of 25 μfiK and a beam diameter of 488 nm. Kirigou invasion, implementation! The experiment was performed using the same operations as A2 and j.

Example 5 A dry film photoresist was obtained in the same manner as in Example 1 using a photosensitive solution having the following composition.

0 Vinyl polymer (acid value 291) 100 parts O tetramethyp-rumethane tetraacrylate 70 parts 03.
3',44'-tetra(tert-butylperoxycarbonyl) Penzophenone 3.5 parts 0 Organic dye compound having the following structure 1 part C2H5Q Steel clad lamination was thermally bonded in the same manner as in Example 1, and the output was 200 mW. Using an argon ion laser, the oscillation line with a wavelength of 488 nm was
Aperture and scan at a speed of 6.2 m/see! performed light. After exposure, the polyethylene terephthalate film was peeled off and exposed to light at 30C in a 1% sodium charcoal aqueous solution.
I did a minute spray genki.

As described above, all of the cured samples 11-7 obtained in Examples 2 to 5 were sharp and strong, and no damage occurred even when etched with a 421f Baume ferric chloride aqueous solution. Thereafter, the cured relief was removed using a 10% aqueous sodium chloride solution to obtain a desired printed circuit board.

Comparative Example 1.2 A dry film photoresist was obtained in the same manner as in Example 1 using a photosensitive solution having a composition other than component (lii) or component (i). When this was scanned and exposed using an argon ion laser, no exposure was observed.

Comparative example 3. 4 Prepare 21 types of commercially available dry film photoresists,
When exposed to light using an argon ion laser, no exposure was observed.

Claims (1)

[Claims] Consisting of a flexible three-layer laminate, the first and third layers of which are transparent polymer films, and the second layer is composed of components (i) to (iv) shown below. A dry film photoresist characterized by being a photosensitive layer containing. (i) An acid value of 50 to 300 and a molecular weight of 10,000 to
500,000 high molecular weight polymer (ii) Monomer having two or more ethylenically unsaturated double bonds capable of addition polymerization in the molecule (iii) Organic peracid ester compound having a benzene skeleton or benzophenone skeleton in the molecule ( iv) At least one type of organic dye compound represented by the following general formulas (I) to (III) ▲ Numerical formula, chemical formula, table, etc. ▼ (I) [R_1 represents an alkyl group having 1 to 4 carbon atoms] ] ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) [R_2 and R_3 are alkyl groups with 1 to 4 carbon atoms, R_4
represents an alkylene group having 1 to 4 carbon atoms. ] ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) [R_5 represents an alkyl group having 1 to 4 carbon atoms]