DE2517656B2 - Photopolymerizable mixture and recording material containing it - Google Patents

Description

2. Photopolymerizable mixture according to claim 1, characterized in that it is used as Binder component (A) a copolymer of vinyl acetate and crotonic acid, a terpolymer of Contains ethyl acrylate, methyl methacrylate and acrylic acid or cellulose acetate succinate.

3. Photopolymerizable mixture according to claim 1 and 2, characterized in that it is used as Binder component (B) toluenesulfonamide formaldehyde, a copolymer of methyl methacrylate and methacrylic acid, a copolymer of Methyl methacrylate and methacrylic acid, a copolymer of methyl methacrylate, ethyl acrylate and Metacryloxyethyl hydrogen maleate, a terpolymer of vinyl chloride, vinyl acetate and maleic acid, an optionally partially esterified copolymer of styrene and maleic anhydride and / or a Terpolymer of methyl methacrylate. Contains ethyl acrylate and methacrylic acid

4. Photopolymerizable recording material composed of a carrier and one applied to it photopolymerizable layer, characterized in that the photopolymerizable layer consists of a photopolymerizable mixture according to any one of claims 1 to 3 has been formed

The invention relates to a photopolymerizable mixture according to the preamble of claim 1, as well as a Photopolymerizable recording material according to the preamble of claim 4.

It is desirable to have photosensitive photopolymerizable compositions which can be developed with aqueous alkaline solutions without the need for an organic solvent because organic solvents are expensive and can be toxic and / or flammable, short of petrochemicals, and air and water can contaminate. In general, the solubility and other properties of the photopolymerizable mixtures are determined by their binder component. This is discussed in more detail below.
Representative publications of the prior art which describe photopolymerizable mixtures which can be developed in aqueous alkaline solutions include: US Pat. No. 2,893,368 (a polymer containing salt-forming groups serves as the binder); US Pat. No. 2,927,022 (a cellulose polymer which contains acid groups is used as the binder); DE-OS 2123 702 (the binder used is a copolymer, for example a methyl methacrylate-methacrylic acid copolymer); DE-OS 22 05 146 (the binder used is an acidic polymer, e.g. a styrene-mono-n-butyl maleate copolymer or a vinyl acetate-crotonic acid copolymer) and DE-OS 23 20 849 (the binder used is a vinyl addition polymer, which contains free carboxylic acid groups, e.g. a copolymer of one or more alkyl acrylates with acrylic acid). Although the photopolymerizable mixtures described in these publications are not without advantages in certain applications, they still have certain deficiencies and disadvantages, especially when they are used as photoresists.

The suitability of photopolymerizable mixtures for dry film resists that are applied as a solid film to a Substrate, generally copper, to be laminated depends on proper mutual coordination several properties, e.g. B. Solvent developability and strippability, but persistence against the etching or plating solutions in the polymerized state, low tack, strong adhesion to Support material and flexibility.

The known photopolymerizable mixtures processed in aqueous alkaline solutions Have one or more of the following disadvantages: They are either too sticky or too too soft or too brittle, or insufficient to produce high-resolution images Adhesion strength to the substrate, or its development time, is even if it is in aqueous Alkaline solutions can be developed overly long. The stickiness leads, for example

to the fact that the photopolymerizable layer dirt including the airborne dust, creating "pores" or holes in the resist can arise. In addition, sticky layers make alignment difficult during lamination Manufacture of the photoresist. Furthermore, some areas of the layer on the cover sheet can be damaged during the Stripping the cover sheet from the layer will adhere. Too much softness of the photopolymerizable Layer can lead to cold flow during storage in rolls, which results in the edges of the layer from layer to layer merge with one another. If there are particles of dirt or lint during the Production are unintentionally rolled up between the layers, cause the resulting local Pressure points allow the resist to flow, creating thin spots in the layer that eventually close Lead to pores and holes in the manufacture of printed circuits. During lamination under Pressure and elevated temperature on the substrate, soft layers flow excessively, as a result of which Distortions and deformations in the photopolymerizable layer in the form of waves or Ripples are created from alternating thick and thin areas.

The object of the present invention is to provide photopolymerizable mixtures which can be developed in a short time with aqueous alkaline solutions and still sufficient are flexible to be laminated to a substrate as a dry film. You must be high Have adhesive strength on the substrate, but must be neither sticky nor too soft and must be during the imagewise exposure to develop such a sufficient different solubility that the polymerizable Areas withstand the developer, but after treatment with a stronger one aqueous alkaline solution containing no organic solvent can be stripped off.

This object is achieved by the characterizing measures of claims 1 and 4, wherein preferred embodiments can be found in the subclaims.

The adhesive strength of the polymer of the binder A to copper is determined as zero as a tear-off value the tear-off test described in Examples 1 to 27.

The solubility in water or in alkaline aqueous solutions is measured as follows: The water or the solution is sprayed onto a 7.6 to 58.4 μm thick piece of the film made of the binder, which is applied to a copper plate. If the film is completely removed from the copper base by the sprayed liquid in 300 seconds, the binder is considered to be soluble in the solution with which it is sprayed. Otherwise the film is considered to be insoluble in this solution. The liquid is sprayed on with a pressure of 1.4 kg / cm ² at a temperature of 26 to 29 ° C. A 0.04N NaOH solution is used as the alkaline aqueous solution.

"Film-forming" means that a uniform, coherent, 7.6 to 58.4 μm thick film forms Copper is formed when the polymer is poured on from a volatile solvent and stored at room temperature is dried.

The invention is based on the finding that excellent photopolymerizable mixtures under Use of conventional initiators and polymerizable compounds can be obtained if these Ingredients with the mixture of the selected acidic organic polymers described above Binders are combined. One might expect that acidic binders would turn out to be alkaline in aqueous Solve solutions, but surprisingly, using the new binder combinations according to the invention photopolymerizable mixtures with sufficient adhesion and flexibility

ίο obtained for the production of photoresists, in particular with improved processability exclusively with aqueous alkaline solutions and reduced sticky wedge and / or softness.
The photopolymerizable mixtures according to the invention are particularly well suited for the production of photoresists because of their superior properties. When used for this purpose, the exposed part of the mixture has sufficient resistance to etching and plating solutions, which are often used in the production of printed circuits and chemically processed parts be used.

The following applies to the individual components of the photopolymerizable mixtures according to the invention to be noted: Any radical-forming photoinitiator systems that initiate the polymerization of the polymerizable Initiate compound and then do not terminate polymerization can be used. That free radical-forming system preferably contains at least one component that has an active radiation

jo absorption absorption band with a molar extinction coefficient of at least about 50 in the range of 340 to 700 μm, preferably from 340 to 500 μm having. Under "active radiation absorption band" is to be understood a radiation band that the formation

J5 caused by free radicals that trigger the Polymerization of the polymerizable compound are necessary. The one that forms the free radicals Photoinitiator system can contain one or more compounds that deliver free radicals immediately, when activated by radiation. It can also contain multiple compounds, one of which Free radicals are formed after they have been activated by a sensitizer that is activated by the radiation. has been suggested.

Examples of suitable photoinitiators are:

Aromatic ketones, e.g. B.

Benzophenone,

Michler's ketone (4,4'-bis (dimethylamino) benzophenone),

4,4 ^C -bis (diethylamino) benzophenone,

4-methoxy-4'-dimethylaminobenzophenone,

2-ethylanthraquinone,
Phenanthraquinone and

other aromatic ketones,

Benzoin, benzoin ether, ζ. Β.

Benzoin methyl ether, benzoin ethyl ether and

Benzoin phenyl ether,
bo methylbenzoin, ethylbenzoin and

One Benzoine and

2,4,5-triarylimidazole dimers, e.g. B.

2- (o-chloropheny!) - 4,5-diphenylimidazole dimer,

2! - (o-Chlorophenyl) -4,5-di (m-methoxyphenyl) -b5 imidazole dimers,

2 :-( o-fluorophenyl) -4,5-diphenylimidazole dimer,

2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer,

2- (p-methoxyphenyl) -4,5-diphenylimide-

azoldimeres,
2,4-di (p-methoxyphenyl) -5-phenylimide-

azoldimeres,
2- (2,4-dimethoxyphenyl) -4,5-diphenylimide-

azoldimeres or
2- (p-methylmercaptophenyI) -4,5-diphenyI-

imidazole dimers,
in US-PS 34 79 185,
in aer GB-PS 10 47 569 and
/ η of US-PS 37 84 557 can be described.

10

Further suitable photoinitiators are the 2,4,5-triarylimidazole dimers (also known as hexaarylbiimidazoles). These are generated with a free radical forming electron donor, e.g. B. 2-mercaptobenzoxazole, leuco crystal violet or tris (4-diethylamino-2-methylphenyl) methane, which is preferred, sensitizers such as Michler's ketone can be added. Various energy contributing dyes such as Rose Bengal CI45446 and Eosin YCI 75 388 can also be used. Further examples of suitable initiators are suitable are mentioned in US-PS 27 60 863 also systems containing a Triarylimidazoldimeres and a free radical generating electron donor with or without a sensitizer compound, such as are described in US-F ¹ S 34 79 185th Another suitable group of initiators are the mixtures described in US Pat. No. 3,427,161.

The concentration of the photoinitiator system which forms free radicals is preferably from 0.1 to 10% by weight, in particular 0.2 to 5.0% by weight, based on the total weight of the photopolymerizable Mixture.

The invention is not limited to the use of certain polymerizable compounds. It is only necessary that the compound is not gaseous, ethylenically unsaturated and is addition polymerizable. One or more of these compounds can be present. A great number useful compounds, which are generally characterized by several terminal ethylenic groups is available. Of the suitable materials its named:

a) Various vinyl and vinylidene monomers, e.g. B. vinyl carboxylates, «-Alkylacrylate, α-substituted Acrylic acids and their esters, vinyl esters, vinyl hydrocarbons, acrylic acid esters and esters of «-Substituted acrylic acids with polymethylene glycols and ether alcohols;

All of these compounds are described in US-PS 27 60 863;

b) the various compounds described in US Pat. No. 2,927,022 (columns 16-17), especially those which contain several addition-polymerizable ethylenic bonds, especially if these are present as terminal bonds, and especially those compounds, in which at least one, preferably most of these bonds with a double bond Carbon atom including a carbon atom double bonded to carbon or Heteroatoms such as nitrogen, oxygen and sulfur are conjugated;

c) Esters of pentaerythritol compounds of the Ar described in US Pat. No. 3,261,686! and

d) Compounds of those described in US Pat. No. 3,380,831 Kind, e.g. B. the Reakticnsprodukt of trimethylolpropane, Ethylene oxide and acrylic and methacrylic acid.

Many of the aforementioned low molecular weight polymerizable components including the Normally contain mono- and polyethylenically unsaturated compounds as they are commercially available are, small amounts (50 to 100 parts by weight per Million) of polymerization inhibitors that prevent spontaneous, thermally induced polymerization, before it is wanted. The presence of these inhibitors, usually of the antioxidant type are, in these amounts, causing no undesirable results when performing the Invention both in terms of sensitivity and quality of the polymerization. As examples suitable inhibitors of thermal polymerization are mentioned:

p-methoxyphenol, hydroquinone,
alkyl and aryl substituted quinones and
Hydroquinones, tert-butylcatechol,
Pyrogallol, copper resinate, naphthylamine,
0-naphthol, copper (I) chloride,
2,6-di-tert-butyl-p-cresol,
Phenthiazine, pyridine, nitrobenzene and
Dinitrobenzene, p-toluquinone, chloranil and
Thiazine dyes, e.g. B.
Thionine blue G (CI52 025),
Methylene blue B (C 1.52 015) and
Toluidine blue O (C. 1.52 040).

The concentration of the polymerizable compound is 7.5 to 35% by weight, in particular 15 to 25% by weight, based on the total weight of the photopolymerizable mixture.

The polymer components contained in the photopolymerizable mixtures according to the invention Binder mixtures can generally be used as previously formed, compatible macromolecular polymers be marked.

Both primary components (A) and (B) of the binder mixture can consist of several polymers exist that are different but meet the respective requirements for these components. the Polymers (A) and (B) are solid at room temperature. The polymers (A) are film-forming, i.e. H. they form a uniform, cohesive film when from solution in an organic Solvent applied and dried at room temperature as described above. the Polymers (B) can, but need not, be film-forming. The films made from certain polymers (B) can thus not evenly and coherently, for example due to wrinkles and cracks in the Be a film that nonetheless adheres to a copper surface on which it was formed.

The photopolymerizable composition contains 15 to each 60Gew.- ⁰ / o (based on the total weight of the mixture) of the polymer (A) and (B). The concentration of the total binder mixture is 55 to 92.4% by weight, based on the total weight of the mixture.

Examples of the polymers (A) and (B) in the binder mixture are given below in Tables I and II

Table I.

Polymers (A)

Polymers

(monomeric components) *)

Acid number ¹ viscosity

mPas

Molecular weight

punki

A. Vinyl acetate (VA) 97% Crotonic acid (CS) 3%

B. VA 95%, CS 5%

C. VA 95%, CS 5%

D. VA 97%, CS 3%

E. Cellulose acetate succinate degree of acetylation 1.85, degree of succinylation 0.42 (US-PS 29 23 673)

F. Ethyl acrylate 56% methyl methacrylate 37% acrylic acid 7%

G. similar to F

H. VA, CS, a benzophenone

18-22 '

76-85

60-70

325 "

14 ⁵
33 "

> 30,000

260,000

30,000 50,000

155 C

38 9-1Γ > 30,000 123 C 36 13-18 ' > 30,000 134 C ⁷ 23 14 ² > 30,000 136 13O2 ³ > 30,000 _

*) Specified instead of the copolymers.

1. Measured with an Ostwald viscometer at 20 C on an 8.6% solution in denatured alcohol.

2. Brookfield viscosity (spindle no. 2, 60 rpm, 25 C), 10% solution in methyl ketone (MEK).

3. As for 2. (but at 12 rpm), 17.5% solution in MEK (60%) and methylcellosolve (40%).

4. As in 2., IOWge solution in CH ₂ CI ₂ .

5. As in 4., 10% solution in CH ₂ Cl ₂ (95%) and isopropanol (5%).

6. Weigh exactly 1.0 g of the well-dried product into a 250 ml conical flask. add about 50 ml of ethanol and shakes or heated to dissolve the polymer. About 10 drops of phenolphthalein solution are added and titrated with 0, In-NaOH in methanol. Each determination is carried out twice. Acid number = (ml NaOH) (NaOH normality) (56.10) / weight of the sample.

7. “Ring and Kugelw Method.

Table II
Polymers (B)

Polymer

(monomeric components)

Acid number viscosity
a 10%
solution Molecular
weight Softening
Point mPas C. 14th 6 ² - 62 9 14 ^y - 96 8-9 16 ³ _ _

AA. Toluene sulfonamide formaldehyde

BB. Methyl methacrylate (MMA) methacrylic acid (MAA)

CC. MMA 68%, ethyl acrylate (EA) 29% methacryloxyethyl hydrogen maleate 3%

DD. Vinyl chloride (VC) 86% vinyl acetate (VA) 13%

Maleic Acid (MA) 1% EE. VC 83%, VA 16%, MA 1% FF. VC 81%, VA 17%, MA 2% GG. More alcohol soluble, with fumaric acid

modified rosin ester HH. Styrene / maleic anhydride resins (SMAn) (1: 1), partially esterified with methanol

YY. SMAn (1: 1), not esterified KK. SMAn (1: 1), not esterified 14 ²

11th 10 ² 26th 10 ² 110-130 8 ²

110-130 8th' 50,000 110-125 277 24 ⁴ 1600 220 480 8 ² 1700 150-170 350 8 ² 140-160

ίο

Continuation

Polymer
(monomeric components) Acid number ' viscosity
a 10%
solution Molecular
weight Softening
Point mPas Ο LL. SMAn (1: 1), partially esterified with isopropanol 270 13 ³ 1700 Ι 60-170 MM. SMAn (2: 1) partially esterified in the same way 220 6 ² 1900 135-150 NN. SMAn (l: l) monoisobutyl maleate 173 13 ⁴ 20000 210 PP. SMAn (1.4: 1) with sec-butyl maleate
partially esterified 177 8 ² 10,000 190 QQ. MMA 92%
MAA 8% 59 16 ⁵ 70,000 - RR. MMA 77%
EA 15%
MAA 8% 50 3O ⁵ 100,000 SS. MMA 56%
EA 28%
MAA 16% 106 3O ⁵ TT. MMA 45%
EA 45%
MAA 10% 70 30 ⁵ UU. Thermoplastic soluble in alkali, 130 14 ³ - 152

Aliphatic modified with rosin
Polyester resin

MMA 82% 119

MAA 18%

7.5 ⁶

1. See footnote (6) to Table I.

2. See footnote (2) in Table I, but 10% in acetone.

3. As 2., 10% in CH ₂ Cl ₂ .

4. See footnote (2) in Table 1.

5. As 2., solvent mixture of 90% CH ₂ Cl ₂ and 10% CH ₃ OH.

6. This value is the relative viscosity of the polymer. The relative viscosity is 11.4 for the polymer RR, 27 for the polymer SS and 15.5 for the polymer TT

It is surprising that the polymer present in different amounts from 15 to 60% by weight (B) as a film in the above-described solubility test in sprayed dilute alkaline Solution is insoluble, but it allows the whole Binder mixture has the required solubility, whereby the non-polymerized layer area of the entire photopolymerizable mixtures when developed exclusively with an aqueous alkaline Solution is readily soluble or dispersible, with a clean, non-smearing surface of the substrate is obtained.

The two polymers (A) and (B) are preferably vinyl addition polymers which contain free carboxylic acid groups contain and preferably from 30 to 94 mol% styrene or one or more alkyl acrylates and 70 to 6 mol% of one or more «j3-ethylenic unsaturated carboxylic acids are produced. As alkyl acrylates for the production of these polymers Suitable binders are, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, Ethyl methacrylate and butyl methacrylate Als oc ^ -ethylenically unsaturated carboxylic acid are suitable for example acrylic acid, methacrylic acid, crotonic acid, maleic acid and anhydrides of these acids.

These polymers can be prepared by any known polymerization process.

In the photopolymerizable mixtures according to the invention, other components, e.g. B. the usual additives. For example, small amounts of a dye can be in the Mixture must be present to determine the position and presence of the remaining polymerized part after leaching the unpolymerized areas of the layer can be identified more easily. The added dye should preferably not have an excessive amount of radiation at the wavelength of exposure absorb or inhibit the polymerization reaction. Examples of suitable dyes of this type are in US-PS 34 79 185 called

If the photopolymerizable mixtures according to the invention on metals, for example for the When applied as a photoresist, an adhesion-promoting agent is often added to them For example, the monomeric or polymeric organic silanes and the nitrogen-containing heterocyclic compounds, e.g. B. benzotriazole described in U.S. Patents 3,645,722 and 3,622,234 to be named.

In addition, other known ingredients, e.g. B. plasticizers and fillers, also in the photopolymerizable mixtures may be present.

The constituents of the photopolymerizable compositions according to the invention are in general mixed together in a material that is a solvent for all components. The one used in each case Solvent is not critically important. It only enables the production of coatings or self-supporting films from the mixtures by a practical method. Suitable as a solvent for this purpose, for example, 2-propanone, 2-butanone, 2-pentanone, 1,2-dichloroethane, methyl acetate, Dichloromethane, trichloromethane and ethyl acetate. When using organic solvents, the Polymers (A) and (B) of course both be soluble therein.

According to a preferred embodiment of the invention, a material which is an image-forming The photopolymerizable layer contains, prepared as follows: A layer of the photopolymerizable mixtures is applied to a suitable carrier film, which has only moderate adhesion to the mixture and remains dimensionally stable with temperature changes. After drying the photopolymerizable Layer a removable cover sheet is laminated on its surface. The photopolymerizable mixture is applied in such an amount that the dry layer has a thickness of about 7.6 μm. the various films made of high polymers, e.g. B. polyamides, polyolefins, polyesters, vinyl polymers and cellulose esters, are made and have a thickness of 6.4 to 203 μm or more are used as carrier films suitable. Of course, if the exposure is made prior to the removal of the carrier film, it must be allow a significant portion of the actinic radiation incident on them to pass through. If the carrier film is in front of the Exposure is removed, these limitations are of course out of the question. Particularly well suited as a The carrier film is a transparent polyethylene terephthalate film with a thickness of about 25.4 μm. As a removable Cover films are suitable, for example, films from the same group of high polymer films described above with a thickness in the same wide range. A thickness of 25.4 μm is particularly suitable Cover sheet made of polyethylene. The carrier films and cover films described above guarantee the photopolymerizable layer good protection. To the layer for example on a printed circuit board To apply to be used rigid support made of copper-clad glass fibers, the cover sheet is from Material is stripped off, and the resist layer on its carrier film is then heated with elastic pressure rollers laminated to the copper side of the rigid support Surface obtained that is immediately ready for exposure, but still against dirt, lint and abrasion is protected by the original carrier film. To produce a resist image the material is exposed imagewise through the carrier film, whereupon the carrier film is stripped off and the exposed Resist is developed by dissolving out the unexposed area with dilute aqueous alkali, whereby a rigid support bearing a relief resist image on its surface is obtained. Because of the high The chemical resistance of the binder mixture from the polymers (A) and (B) can be achieved by the material then subjected to the usual plating or etching operations, as would be apparent to those skilled in the art are known in the art of using resist images.

The preferred method of forming photoresists on metal or other surfaces including Glass or ceramic with the photopolymerizable compositions according to the invention include the following Stages:

1) The photopolymerizable mixtures are applied directly to this surface as dry, solid layer with a thickness of at least

ίο 1.3 μm and low to moderate adhesion to one

thin, flexible polymer film, preferably during application or later is heated to a temperature of 40 ° to 150 ° C to to increase the adhesive strength between the surface and the layer. Then in the said The following actions are carried out in the order:

2) The layer is exposed imagewise to actinic radiation, thereby producing a polymer image on the surface.

3) The carrier film is peeled off from the layer carrying the image.

4) The unexposed areas of the layer are removed and a resist image is thereby formed Polymer material made with aqueous alkaline solutions that are not organic solvents contain, can be developed.

5) The areas on the surface that are not protected by the resist image are permanently modified by using a reagent that will etch the unprotected areas or put a material on it able to separate these areas.

The surface can then be treated or plated or otherwise treated with a suitable reagent to form an etched surface. The polymer image can then be treated with an aqueous caustic alkali solution containing no organic solvent, with or without the aid of mechanical means, e.g. B. can be removed by rubbing, brushing and / or grinding or a combination of several of these measures.

This process is suitable for making decorative photo engravings and chemically processed ones and electrolytically formed elements.

Examples of metal surfaces that can be etched are magnesium, zinc, copper, alloys of these metals, aluminum, anodized and colored anodized aluminum, steel, steel alloys and beryllium-copper alloys to call.

The development of the imagewise exposed photopolymerizable Mixtures according to the invention are not limited to the development involved in the one described here Solubility test takes place, limited The solubility test provides a means of comparing the Development times. Customary, exclusively aqueous alkaline development solutions and apparatus can be used.

The photopolymerizable mixtures according to the invention are particularly suitable for photoresists, however, the noted advantages can be applied to other photopolymers including the washing out with solvents can be realized. For example, the photopolymerizable Mixtures according to the invention for the formation of photopolymerizable layers on aluminum be used for the production of planographic printing plates, as described in US Pat. No. 3,458,311.

The invention is further illustrated by the following examples, in which the amounts are given in parts and percentages are by weight unless otherwise specified.

Examples 1 to 27

These examples describe the adhesive strength test and that of the acidic organic rating Polymers as polymers (A) or (B) serving solubility test. The polymers were each in dissolved in an organic solvent, applied to copper with a doctor blade and exposed to air dried. The thickness of the dry layer was measured. Furthermore, the adhesive strength and the Film-forming capacity of the polymers determined. Quantitative adhesion and solubility data were also determined on the coated samples. The adhesive strength (anchoring) was measured with the help of a Tear-off tests determined. The solubility was measured in a leach test. Both tests are below described in detail.

Thus photopolymerizable mixtures as photoresists are suitable, they must be at least moderately good on the substrate, ζ. B. copper, adhere. As the binder normally the major component of the photopolymer compositions, the binder itself must be sufficient Adhesion (anchoring) to the substrate, ζ. B. copper have. A simple method of determination the cohesion of such a laminate (i.e. the binder layer on copper) consists in the Degree of delamination, d. H. the degree to which the organic make coat or film is dated Layer base is removable to measure. Tests of this type are well known and are, for example, in the U.S. Patent 3,615,557, Example I, is described. A similar method was used in the present case.

The adhesive strength test was carried out as follows: Using a template, it became the above described dried laminate of polymer and copper with a knife through the polymer layer scored to form 3.175x3.175 mm squares. A piece of one Pressure-sensitive adhesive strip with cell glass as the carrier material was then pressed onto the surface treated in this way. A the loose end of the adhesive tape was gripped at an angle of about 90 ° to the layer surface. The adhesive tape was abruptly withdrawn and the number of squares remaining on the copper was counted. By Compare the number of squares on the tape after it was suddenly removed with the original The number of squares incised (generally about 50) can make the percent peeling easy be calculated.

In the solvent development of typical photopolymerizable layers, it is necessary to remove unexposed, unpolymerized areas from the copper with a solvent. Since özs binder is the larger component of the layer, the binder layer itself must be easily removable from the substrate (ζ. B. copper). The time required to completely wash off the binder layer from the laminate consisting of binder and copper was determined by spraying on dilute aqueous NaOH (0.04 η, 0.16%) at 26 to 29 ° C. The laminates were attached to a rocking plate 15.24 cm from the spray nozzles. A pump was used to spray the liquid at 1.4 kg / cm ² . In the holes of the used. Nozzles, a 2mm drill bit, but not a 2.4mm drill bit, can be inserted.

The results obtained for the binders mentioned in Tables I and II for those described above Tests obtained are summarized in Table III below.

Table III

Splitting and washing out of polymer / copper laminates

example Short name Film thickness Remarks Splitting up 0 Wash out No. of the polymers in 0 Tables I and II μίτι % 0 Seconds 1 A. 23.9 film-forming 0 180 2 B. 17.8 film-forming 0 20th 3 C. 19.3 film-forming 0 35 4th D. 56.4 film-forming 0 60 5 E. 10.4 film-forming 0 30-40 6th F. 15.5 film-forming 100 40-50 7th G 20.3 film-forming 0 15th 8th H 16.5 film-forming 0 30th 9 AA 17.8 film-forming 0 > 300 10 BB 11.2 film-forming 0 > 300 11th CC 16.5 film-forming > 300 12th DD 7.4 film-forming > 300 13th EE 17th film-forming > 300

continuation

example

Short name
of the polymers in
Tables I and II

f-foil thickness

Comments splitting

Wash out seconds

14th
15th
16
17th
18th
19th
20th
21
22nd
23
24
25th
26th
27

FF

GG

HH

YY

KK

LL

MM

NN

PP

QQ

RR

SS

TT

UU

9.4 28.7 16

no test no test 28.4 14.7 16.3 14 15.5 18.3 20.3

8.1 13.2

film-forming brittle layer film-forming brittle, flaky, brittle, flaky brittle, cracks brittle foil foil foil foil foil foil brittle foil

0 > 300 100 > 300 0 > 300 no test no test no test no test no test > 300 100 > 300 0 > 300 0 > 300 track > 300 track > 300 0 > 300 0 > 300 100 > 300

Comparative experiments I - X VI I

A number of the same photopolymerizable mixtures that only have a polymer as a binder was made and used to make photoresists. The polymer was either a polymer (A) or a polymer (B) is used. The photopolymerizable mixture had the following composition:

Triethylene glycol dimethacrylate 20 g Benzophenone 4g Michler's ketone 0.2 g C. 1.42 595 0.1g binder 75.7 g

4th

Copper-clad epoxy resin fiberglass panels were rubbed with an abrasive and cleaning agent, Wipe clean and rinse well in water and then air dried.

The photopolymerizable mixtures were coated onto a 25.4 μm thick transparent polyethylene terephthalate film using a doctor blade set to 152.4 μm and then dried in the air. Each resist layer with its substrate was laminated to the clean copper with the surface of the photopolymerizable layer laid on top of the copper surface. The lamination was carried out with the aid of rubber-coated rollers operating at 100 to 115 "C, under a pressure of 0.54 kg / cm at the nip at a speed of 61 cm / min. which were protected as such by the polyester film could be stored for later use as required. In the present case, they were exposed through a high-contrast transparent image in which the circuit diagram appeared as transparent areas on an opaque background. The exposure was carried out by the A photosensitized copper-clad plate (with the polyester film still attached) and the original were placed in a photographic frame. A scanning mercury arc lamp under a vacuum of 635 mm was used as the radiation source (exposure). After exposure, the polyethylene terephthalate carrier film was stripped off and discarded , whereby that exposes ete resist stuck to the copper surface. The plate was then developed by spraying it with 0.04 η NaOH at 26 to 29 "C and 1.4 kg / cm ² in the manner described in the previous examples. By this measure, that with the dye CI 45 595 remained Dyed resist adhered to the copper in the pattern of the transparent areas of the template, while no resist adhered to the plate in the areas that corresponded to the opaque areas of the template.

The plates were then etched with ferrous chloride solution at 45 ° Be. The plates were in the Etching machine held until the copper in the areas not covered by the resist image was completely etched away was. The etched plate was rinsed with water and dried, leaving the conductive covered with the resisi Copper image remained on the fiberglass board. The resist was then removed from the copper by 3% NaOH was sprayed on at 55 ° C for 1 to 3 minutes. The panels that after developing are unsatisfactory looked like, d. H. in which the unpolymerized areas were not removed, were im generally not etched.

The polymers tested, the organic solvents used, the thickness of the resist, the Exposure time, development time, etching behavior and other observations are given below shown in Table IV.

030 146/160

IV Short- 17th I. CH ₃ COC ₂ H ₅ 25 1 7 656 Exposure Development 18th Remarks properties of designate (MEK) tion wick- Tabel Ver the Comparison resists CH ₂ Cl ₂ (92.5) Time lung equal Polymers Coating Time etching example in table solvent CH ₂ CI ₂ (92.5) Co-solution thickness No. and II MEK (60) mean of Sec. Sec. A. Resists 60 300 sticky I. B. 60 30th soft, μπι Well Indentations II C. CH ₂ Cl ₂ (92.5) - 24.9 75 30th sticky E. 90 25th Well Monomer III CH ₃ OH (7.5) 27.4 the end IV Well sweated, CH ₃ OH (7.5) 30th Well bad CH ₂ Cl ₂ (85) Methyl- 22.4 liability F. cellosolve (40) 60 30th sticky, CH ₂ CI ₂ (92.5) soft, V MEK Ripple Well after CH ₃ OH (7.5) 30th lamination G 75 30th sticky, CH ₂ Cl ₂ Pressure points VI H MEK 75 30th soft AA CH ₂ CI ₂ - - Well very sticky VII iC, H ₇ OH (15) 27.4 Layer, VIII Well no CH ₃ OH (7.5) 27.4 - Film formation CC MEK - 15.2 60 > 300 - EE acetone 60 > 300 - IX GG CH ₂ CI ₂ (92.5) 60 30th at 25 C X - laminated, XI - 27.4 - soft, - 27.4 Well Ripple HH - 30th 60 > 300 - IUI MEK 60 > 300 - XII LL - - very brittle XIII - Foil; no XIV CH ₂ CI ₂ (92.5) - 24.9 - Liability to - 30th - Copper at CHjOH (7.5) 27.4 Laminate PP MEK - - same Results XV as with LL SS 60 30th - - 27.4 XVI UU CII ₂ CI, 60 30th so bad soft, CII ₃ OII (7.5) 27.4 (ver Ripple; XVII lubricates) had to? Well 25 C } - 27.4 laminated> 4 become (1 VV 60 > 300 y XVIII - CH ₁ OII 35

Examples 28-49

Photopolymerizable mixtures according to the invention were prepared and rated as resists in the same manner as in the comparative tests the exceptions mentioned in the summary of the results in Table V.

The following abbreviations are used in Table V:

TDMA

TMPTA

PETA

Triethylene glycol dimethacrylate
Trimethylol propane triacrylate
Pentaerythritol tri- and tetraacrylate, about 60:40

BP = Benzophenone MK = Michler's ketone, 4,4'-bis (di- methylamino) benzophenone HABI = 2-o-chlorophenyl-4,5-diphenyl imidazolyldiineres (2,2'-bis- (o-chlorophenyl) -4,4 ', 5,5'-tetra- phenylbiimidazole) Leuco dye = Tris- (4-N, N-diethylamino- o-tolyl) methane 2-Aq = 2-tert-butylanthraquinone 2-EtAq = 2-ethylanthraquinone MEK = Methyl ethyl ketone

Table V

Properties of resists according to the invention

example Monomer Polymer Polymer Photoinitiator Coating thickness Exposure Development etching No. (20 g) (Tab. I) (Tab. II) system solvent of tion wick- Resists Time lung Time G G μηι Sec. Sec. 28 TDMA F (30) LL (45.7) BP (4); MK (0.2) CH ₂ Cl ₂ (200) 30th 60 30th Well 29 TDMA F (15.7) LL (60) BP (4); MK (0.2) CH ₂ Cl ₂ (200) 27.4 90 30th Well 30th TDMA B (60) SS (15.7) BP (4); MK (0.2) CH ₂ Cl ₂ (185) 30th 60 30th Well CH ₃ OH (15) 31 TDMA C (60) PP (15.7) BP (4); M K (0.2) CH ₂ Cl, (200) 24.9 90 30th Well 32 TDMA E (45) AA (30.7) BP (4); MK (0.2) MEK (127) 24.9 30th 30th Well Methylcello solve (35) 33 TDMA A (60) GG (20.7) BP (4); MK (0.2) MEK (200) 24.9 40 40 Well 34 TDMA A (50) GG (25.7) BP (4); MK (0.2) MEK (200) 27.4 50 30th Well 35 TDMA B (60) EE (15.7) BP (4); M K (0.2) MEK (200) 27.4 60 60 Well 36 TDMA G (55) CC (20.7) BP (4); MK (0.2) as in example 35 27.4 105 180 Well 37 TDMA B (60) AA (15.7) BP (4); MK (0.2) Acetone (200) 24.9 60 90 Well 38 TMPTA B (60) AA (15.7) HABK4) leuco Acetone (200) 24.9 60 150 Well fair material (0.4) 39 PETA B (60) AA (18.3) 2-Aq (l, 6) Acetone (200) 24.9 180 105 Well 40 TDMA H (15.7) LL (60) BP (4); MK (0.2) CH ₂ CI, (200) 26.7 90 60 Well 41 TDMA B (15.7) LL (60) BP (4); MK (0.2) CH ₂ CI ₂ (200) 24.9 75 90 Well 42 TDMA C (60) EE (15.7) BP (4); M K (0.2) CH ₂ Cl ₂ (200) 26.2 60 60 Well 43 TDMA G (30) PP (45.7) BP (4); MK (0.2) MEK (187) 22.1 75 30th Well i-CjH ₇ OH (13) 44 TDMA A (25) LL (5O, 7) BP (4); MK (0.2) MEK (200) 24.9 40 90 Well 45 PETA B (60) AA (19.5) 2-EtAq (0.4) Acetone (200) 24.9 180 100 Well 46 PETA B (60) AA (19.1) 2-EtAq (O, 8) Acetone (200) 27.4 180 105 Well 47 TDMA H (15.7) U U (60) BP (4); MK (0.2) CH ₂ CI ₂ (200) 27.4 75 30th Well 48 TDMA A (55) U U (20.7) Bl '(4); MK (0.2) CII ₂ CI ₂ (185) 30th 60 30th Well 49 TDMA A (60) U U (15.7) BP (4); MK (0.2) CH ₂ Cl, (185) 27.4 60 30th Well

Besides the data in Table V, the benefits for the photopolymerizable compositions according to the invention were observed by the

The following remarks on the suitability of the mixtures as resists are further illustrated.

Example remarks Example remarks

(Comparison with the results in Table IV) (Comparison with the results in Table IV)

28 Flexible, well adhering, non-sticky film; no curling when laminating.

29 As in example 28.

30 No softness, no pits, no smudging.

31 Flexible, non-sticky film, good ones Liability.

32 Non-sticky film, good adhesion, no monomer exudation.

33 No curling during lamination.

34 As in example 33.

35 No smudging, no softness.

36 Non-tacky film, no puckering or bruising.

37 Non-sticky film, no softness or pits.

38 As in example 37.

39 As in example 37.

40 Flexible, well adhering film, no heat or indentations.

41 As in example 40.

42 Non-tacky film, developed without smearing.

43 Flexible, well adhering film, no stickiness, softness or pits.

44 Non-tacky film with good adhesion to copper.

45 As in example 37.

46 As in example 37.

47 No softness or frizz.

No curling during lamination. As in example 48.

50

example

A photopolymerizable mixture was prepared containing the following ingredients:

Copolymer of methyl meth- 13g acrylate and methacrylic acid (Binder BB) 1.5 g Polymethyl methacrylate, Molecular weight 258,000 Plasticizer from a mixture 0.8 g of triethylene glycol dicaprate 3.4 g and dicaprylate Trimethylol propane triacrylate 10% solution of a terpolymer of ethyl acrylate, methyl meth- 13g acrylate and acrylic acid in 0.1g Ethyl Cellosolve (Binder F) 100 g M ichlers ketone 43 g Trichlorethylene as a solvent 0.4 g Ethyl Cellosolve o-chlorohexaarylbiimidazole

This solution was coated onto a polyester carrier film and dried, one layer being a Thickness of about 12.7 μm was obtained. The dried one Layer formed a uniform, well-cohesive film that was not tacky. The layer was imagewise exposed for 30 seconds with a xenon arc lamp and in a 10% aqueous solution Sodium carbonate solution containing no organic component was developed. The unexposed areas were completely removed by the developer, with the exposed, polymerized areas on the Backing film remained.

Claims (17)

Patent claims: 1. Containing a photopolymerizable mixture 1) 0.1 to 10% by weight of an organic radiation-sensitive free radical forming photoinitiator system, 2) 7.5 to 35 wt .-% of a non-gaseous ethylenically unsaturated compound which a high polymer through a chain addition polymerization initiated by free radicals able to form and 3) 30 to 92.4 weight percent polymeric binders characterized in that it 4) a mixture of 15 to 60% by weight of one Contains binder A with 15 to 60% by weight of a binder B, wherein 5) the binder A is an acidic organic film-forming polymer which 6) is insoluble in water at 26 to 29 ^{0 C,} 7) a molecular weight of at least 30,000 and 8) has an acid number of at least 20, 9) and is capable of producing an even cohesive film on copper form when the polymer is poured from a volatile solvent and at Room temperature is dried, 10) this film with a thickness of 7.6 to 58.4 μπι 11) a tear-off value in the cross-cut tear-off test from 0 shows and 12) is completely soluble within 5 minutes when sprayed with an aqueous 0.04 η NaOh solution at a pressure of 1.4 kg / cm ² at 26 to 29 ° C, and 13) the binder B is an acidic organic polymer, 14) which is insoluble in water at 26 to 29 ° C, 15) has an acid number of at least 5 and 16) as a film with a thickness of 7.6 to 58.4 μm when sprayed with an aqueous 0.04 η NaOH solution at a pressure of 1.4 kg / cm ² at 26 to 29 ^° C. within 5 minutes is soluble 17) and with all weight percentages based on the weight of the entire substance mixture of the Relate photopolymerizable recording material.