JPS61134756A - Making of photoresist - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides novel photosensitive compositions comprising:
-Relating to a method of manufacturing. Since it is resistant to such photoresist coating solutions, it is used as a photoresist for printed circuits, and is also useful as a molding material for screen stencils and printing plates.

Organic solvents are generally costly, toxic, and also flammable. Moreover, it also has the disadvantage of polluting the air and water. Therefore, it has long been desired to obtain a photosensitive composition that can be developed without using such organic solvents. A system developed with an alkaline aqueous solution without using such an organic solvent is described in British Patent No. 1.36],298.

Although the composition described in British Patent No. 1.36+,298 is very useful for its intended purpose, it is extremely inflexible when used as a dry film laminate. It has the disadvantage of being

A brittle film not only cracks during or prior to use, but also has the drawback of failing to properly rinse the master roll when the user cuts the master roll to the desired size. In addition, a sliver is formed at the end of the Surin I roll, which has the disadvantage of separating the photopolymerizable N, (2) acid layer from the base polyester layer. In the region where this phenomenon occurs, the photopolymerizable composition layer is not adequately exposed to light, and the resist 1 after development is damaged. lose u. Like this ■
Even if the film were to be used as a circuit board, it would not be useful in flexible circuit designs because it would crack when the board was bent or the film would peel away from the board.

Conventionally known means include incorporating external plasticizers to improve flexibility. However, depending on this method, the plasticizer may cause migration over time.
Again, it was not always satisfactory. In particular, cold flow is an intolerable drawback since the roll of film is placed under static load and the photopolymerizable material begins to ooze out from between the layers within a short period of time. This seeping material melts at the ends of the roll, making it difficult, if not impossible, to unwind it from the roll uniformly and without damaging the opposing film. Furthermore, when producing a film from a composition containing the external plasticizer, if drying is not accurately controlled, the plasticizer will evaporate and the film will remain brittle.

The present invention consists in the discovery of water-developed photopolymerizable compositions that exhibit good flexibility even in dry films without external plasticizers and at the same time have high cold flow resistance. In addition, the areas where this composition is exposed to light and modified into a polymer are resistant to typical solutions used in the manufacture of printed circuits and chemical mechanical parts, such as alkaline etching agents and alkaline plating solutions. Shows remarkable resistance.

In summary, the advantage of the present invention is that a copolymer consisting of (1) a styrene type monomer, (2) an acrylate type monomer, and (3) an unsaturated carboxyl group-containing monomer is selected as a polymer binder for a compatible macromolecule. There is a particular thing.

The first component imparts hardness and chemical resistance to the polymer;
The second component imparts flexibility and plasticity to the polymer skeleton, and the third component imparts alkali solubility.

The photopolymerizable composition of the present invention comprises +1.1 1 0 to 60 parts by weight of a +111 ordinary addition polymerizable, non-gaseous ethylenically unsaturated compound; +21 4. It consists of 0 to 90 parts by weight of the binder and (3) 1 to 10 parts by weight of a conventional free radical photoinitiator. Conventional thermal addition polymerization inhibitors are also used, preferably up to 5 parts by weight a; r-o. o 0
Up to 5 to 2.0 parts by weight may be added. Additionally, the compositions may be useful for improving the physical and chemical properties of dyes, pigments, and other photopolymerizable compositions. For example, additives such as plasticizers and adhesion promoters may be added.

Ethylenically unsaturated compounds have at least one terminal ethylene group (C112=Cζ) and have 1
It must have a boiling point of 00 DEG C. or higher, and must also form a high molecular weight polymer in a chain polymerization reaction using a free radical photopolymerization initiator. Such compounds are
Disclosed in U.S. Pat. No. 2,760.863.

This compound is liquid or solid at room temperature and has 1
It is desirable to have up to 4 or more terminal ethylene groups, preferably 2 or more, and to have a plasticizing effect on the thermoplastic polymerizable binder. Preferred compounds include al:1-lenes or polyalkylene glycol diacrylates synthesized from alkylene glycols having 2 to 15 carbon atoms or polyalkylene ether glycols having 1 to 10 ether bonds. These can be used alone or as a mixture.

The speed at which it becomes insoluble upon exposure to light is probably due to the rapid formation of a network structure of the polymer; Compounds in which this ethylene bond is terminal, in which one of the bonds forms a double bond with carbon, i.e., a carbon-carbon double bond, or a heteroatom such as nitrogen, oxygen, or sulfur; A component having a residue present in conjugation with carbon is the best. Among these compounds, those in which an ethylenically unsaturated group, especially a vinylidene group, is conjugated with an ester or amide structure are preferred.Next,
The identified compounds are intended to further illustrate these groups of compounds. Unsaturated esters of polyols, especially esters of methylene carboxylic acid, such as ethylene diacrylate; diethylene glycol diacrylate; tetraethylene glycol diacrylate; glycerin'
;f")'J Le-I;) Dimethylolpropane 1-reacrylate; Glycerin triacrylate; Ethylene dimethacrylate; 1,3-propylene dimethacrylate-1-il, 2,4-butanetriol i-remethacrylate -1.; 1.4-henzendiol dimethacrylate-1.; .4'-(2-hydroxyethyl)phenyl-
Bis-acrylates or bis-methacrylates consisting of polyethylene glycols such as 2,2'-propane, ethoxylated alcohols and phenols; unsaturated amides, especially methylene carboxylic acid and methylene bis-acrylamide; methylene bis-methacryl-amide; 1.6- α,Ω-diamines such as hexamethylene bis-acrylamide; diethylenetriamine tri-meccrylamide; bis(methacrylamidopropoxy)ethane; β-methacrylamidoethyl meccrylate, N-((β-hydroxy-ethyloxy)ethyl)acrylamide, etc. and amides of Ω-diamines with oxygen atom intervening;
vinyl esters such as divinyl adipate, divinyl phthalate, divinyl terephthalate, divinylbenzene-1,3-disulfonate, and divinylbutane-1,4-disulfonate; unsaturated aldehydes such as sorbaldehyde (hexadienal);

Preferred monomers are di- or polyfunctional monomers, although monofunctional monomers can also be used.

The amount of monomer to be added will vary depending on the particular thermoplastic polymer.

The styrene-type component of the polymerizable binder is a compound represented by the general formula % where R is hydrogen, an alkyl group having 1 to 6 carbon atoms, or a halogen. The Hensen ring may be substituted with a functional group such as a nitro group, an alkoxy group, an acyl group, a carboxyl group, a sulfo group, a hydroxy group, or a halogen. Residues to replace the benzene nucleus are 1-
It may be in the range of 5. Preferred substituents are single alkyl groups such as methyl or t-butyl groups. The most preferred compound among the above-mentioned compounds is styrene α-
They are methylstyrene, paramethylstyrene and para-t-butylstyrene.

The acrylate-type component is an alkylhydroxyalkyl acrylate having an alkyl group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms, or an alkyl, hydroxyalkylmethacrylate-1-.

Examples of these compounds include methyl methacrylate, ethyl acrylate, hydroxyalkyl acrylate,
Hydroxyethyl methacrylate and hydroxyethyl acrylate. A mixture of two or more of these compounds may also be used.

Examples of the third comonomer include one or more unsaturated carboxyl group-containing monomers having 3 to 15 carbon atoms, preferably 3 to 6 carbon atoms. The most preferred compounds include acrylic acid and methacrylic acid. Other acids that may be used include cinnamic acid, crotonic acid, sorbic acid, itaconic acid, propiolic acid, maleic acid and fumaric acid.

Also possible are their half-esters or anhydrides.

The proportions of the three components in the binder must be selected such that the photopolymerizable composition incorporating the binder has the following properties: That is, first, the photopolymerizable composition must be flexible and hard. However, it should not be sticky. Second, the unexposed photopolymerizable material must be developed in a mild aqueous alkaline solution or an etching agent (all
Fourth, the viscosity of the 40% methyl ethyl ketone solution of the binder must be at least 2000 centivoise. The preferred range of this viscosity is 250
0 to 8000 centivoise. All viscosity measurements were made using a Brookfield viscometer.

The weight proportions of the three monomer components used to synthesize the binder are shown in the following table.

Binder component Wide range Suitable range Styrene type
40-60% 45-55% Acrylic'-1'' type 15-45% 25-35% 1
The following coating and drying methods are used for laboratory production of carboxylic acid type 15-40% 18-30% dry films. That is, all the components are mixed into a methyl ethyl ketone solution and stirred to prepare a coating solution.

Roughly dilute this solution with ketone solution to bring the viscosity to 100.
Make it ~200 centimeter voice. This coating is applied onto a 10 foot long by 5 cm wide polyester membrane spread over tempered glass. A uniform thin film is formed using a Meyer rod or a Gardner doctor knife.

The thickness is adjusted so that it becomes a 2 mil thick film after drying.

Drying is performed using, for example, a 150 watt dryer. The dryer is placed at one end of a laboratory-scale tunnel that can perform total drying. Dry the film by blowing hot air continuously for 20 minutes until the amount of residual solvent is about 0.1-2%. This amount of residual solvent does not impair the chemical and physical properties of the dried film resist.

The flexibility of a dry film is measured by crumpling the film and then stretching it. If the film is dangerous when such a large number of folds are accumulated, cracks or I+ separation will occur. On the other hand, if the film is flexible, it will remain in continuous sheet 4.

Flexibility and drying latitude are also determined by a test method in which sample films are overdried for 10 minutes at 7180° F. in a forced convection oven. Of course, the overdried sample is subjected to the test method described above. An industrial method for measuring the cold flow properties of unsupported photopolymer films as thin as 1.2 mils is:
Due to the nature of the film itself, nothing has been confirmed.

The best practice is to roll at least 500 feet of 2 mil photopolymerizable film onto a core under normal tension and allow the film to stand on its edges at room temperature for a significant period of time. If the film is in good condition, 65° to 75° for 6 months.
Even on the 6th floor, on the edge? The phenomenon of melting does not occur.

There are two qualitative measurements that are closely related to the empirical cold flow measurements described above. One is the SWORD hardness method, and the other is the “cold-flow-under-νacuum” method.
).

The SWORD hardness index is expressed as the ratio of the surface hardness of a sample film to the surface hardness of standard glass. The SWORD SOCAR is first calibrated to a reading of 100 on the glass, and then a reading of a sample film laminated to the same glass sheet is taken. A good 1 mil water developable film has a SWORD hardness of 10-20, and a 2 mil film has a SWORD hardness of 8-14.

In the vacuum cold flow method as a static load,
The sample film is laminated to the copper, then the polyester substrate is placed in place and a thin wire (12-13 mil diameter) is placed on top. The entire system is placed under a vacuum of 2 inches Ilg for 5 minutes. After processing, the polyester substrate is carefully removed and the wire graduations are photographed as well as the "bleed" from the edges of the film. A photograph of this film is compared with a film with known cold flow properties.

As previously mentioned, the resist comprising the composition of the present invention is
Resistant to normal plating solutions and esotynda solutions. Most surprising is the resistance to copper pyrophosphate solution. Copper pyrophosphate is used for plating and has a very high alkalinity.

Other solutions that do not affect the resist include ferric chloride,
There are ammonium persulfate and chromium sulfate solutions.

It is recommended that the photoinitiator used in the compositions of the present invention be a material that can be activated with actinic radiation and is not thermally activated at temperatures of 185° C. or lower.

These substances include substituted or unsubstituted polynuclear bovine nons such as: 9,10-anthraquinone;
1-chloroanthraquinone, 2-chloroanthraquinone, 2-methyl-anthraquinone; 2-ethylanthraquinone; 2-tert-butyl-anthraquinone; octamethylanthraquinone; 1,4-natsutaquinone; 9,
10-phenanthraquinone; 1,2-benzanthraquinone; 2,3-henzanthraquinone; 2-methyl-1
, 14-natsutaquinone; 2,3-dichloro-phtani 1
-non; 1,4-dimethylanthraquinone; 2,3-dimethylanthraquinone; 2-phenylanthraquinone;
233-Diphenylanthraquinone; Anthraquinone α-sulfonic acid sodium salt; 3-chloro-2-methylanthraquinone; Retinquinone i7,8
．． 9.10-tetrahydronaphthacenequinone; t, 2,
3.4-tetrahydrobenz(al anthracene-7,
12-dione.

Also useful as photopolymerization initiators are vie-ketaldonyl compounds such as diacetyl and benzyl; α-ketaldonyl alcohols and ethers such as benzoin and pivaloin; benzoin methyl and ethyl ether, and α-hydrocarbon substituted aromatics. Acilloins such as α-methylhenzoin, α-allylbenzoin and α-phenyl-benzoin; and α,α-dialkoxyacylphenones such as α,α-jethoxyacetophenone. Useful polymerization initiators include aromatic ketones such as benzophenone and 4,4'-bisdialkylamino-benzophenone, especially the dimethylamino compound known as the old cheer ketone.

Although it is generally preferable to incorporate an inhibitor that does not cause a thermal polymerization reaction during drying and storage, it is not necessarily essential for photopolymerizable compositions. Such thermal polymerization inhibitors include P-methoxyphenol, hydroquinone, and alkyl or aryl substituted hydroquinones or quinones, tert-butylcatechol,
Copper pyrogallol resinate, naphthylamine, β-naphthol, cuprous chloride, 2,6-di-tert-butyl p-
Cresol, 2,2-methylenebis(4-ethyl-6-
t-butylphenol), phenothiazine, pyridine,
Nitrobenzene, dinitrobenzene, p-torquinone,
There are chloranil, aryl phosphites, and arylalkyl phosphites.

If desired, the composition may contain dyes and pigments. The optimal colorant is one that is compatible with the photopolymerizable composition and does not have any effect on photosensitivity.

The following listed compounds are illustrative of such colorants; Tsuksin (C,1,42510) Auramine Base (C,L 4100OB) Calcocytogreen S
(C, 1, 44090); Balamadienta (C, T,
42500); I-rivarozan (C, 1,42505
); 21-Mazienc (C,T.

, 12520); AcisodohyolesothoRRF ((C,
1,42/1.25) i Resodo High Resodo 5R3 (C
, T, 42690); Nile Blue-2B (C, 1°51
185); new methylene blue GG (C,?.

51195); C, 1, Paysic Blue 20
(C, I.

4.2585), Iosine Green (C, L4255)
6); Night Green B (C, 1, 42115); c
, r, Direct Yellow 9 (C, 1, 19540
); C, 1, acid yellow 17 (C, 1, 18
965) iC, 1, acid yellow 29 (C, L
18900) i Tartrazine (C, 1, 19140
); Subramin Yellow G (C, L 19300)
;Buff Arrow Black IOB (C, 1, 27790)
; Nafclenbrasok 12R (C, 1, 20350),
Fast Black L (C, 1, 51215); Ethyl Hiolesotho (C, T, 42600); Bontasil Wool Blue BL (C, 1, 50305); Bontasil Wool Blue GL (C, 1, 52320); (
, according to Color Index 2nd Edition).

Photopolymerizable element 4j is exposed to chemically active radiation. This exposure is performed using a halftone image or process transparency, such as a process negative or positive stencil or mask. Exposure may also be carried out in a series of negative or positive images. Exposure may be carried out by a contact method or a projection method, with or without a cover sheet provided on the photopolymerizable layer, or by projection using cover sheets 1 to 4. These methods will be obvious to those skilled in the art.

The polymerization initiator, which generates free radicals, is activated by chemical radiation (actinic radiation), and its sensitivity is greatest in the ultraviolet region.

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Valid °” people 1.t i-.

It should be the one that is. Point or area radiation sources are effective. Such radiation sources include carbon arcs, mercury vapor arcs, fluorescent lamps with ultraviolet-emitting phosphors, argon glow lamps, electrosensors, and photographic flood lamps. Among these, mercury vapor arc and solar lamps are particularly suitable. In some cases, exposure to visible light may be used. In this case, it is necessary to use a photoinitiator sensitive to visible light. Examples of this photoinitiator include 9,10-phenanthrenequinone.

Of course, it goes without saying that a radiation source that effectively emits visible light is used. Many of the radiation sources mentioned above provide the required amount of such visible light.

After exposure, the photopolymerizable composition is developed, for example by impingement with a spray jet, by dipping with agitation, or by brushing, scraping, etc. Among these developing methods, brushing and scraping methods have a density of 0.01
The desired image is developed using a ~10% by weight aqueous alkaline solution.

Bases for development include alkali metal hydroxides, i.e. hydroxides of lithium, sodium and potassium; base reaction alkali metal salts of weak acids, i.e. carbonates or bicarbonates of lithium, sodium and potassium; basicity approx.
-6 or more amines, such as benzyl, butyl, and allylamine; secondary amines, such as dimethylamine, benzylmethylamine; tertiary amines, such as trimethylamine, l-ethylamine; primary, secondary, and tertiary hydroxylamines; For example propatool, jetanol, triethanol amines and 2-amino-2-hydroxymethyl-1,3-propanediol; cyclic amines such as morboline, piperazine, piperidine, pyridine;
Polyamines such as hydrazine, ethylene and hexamethyleneamine; water-soluble basic salts such as carbonates or bicarbonates of the above amines; ammonium hydroxide and tetra-substituted ammonium hydroxides such as tetramethyl-, tetraethyl-, trimethylbenzyl-1 and trimethyl Phenyl aluminum hydroxide, sulfonium hydroxide e.g.

trimethyl-, diethylmethyl-, dimethylbenzylsulfonium hydroxide and their soluble basic salts such as carbonates, bicarbonates and sulfides; alkali metal phosphates and pyrophosphates such as potassium or strontium phosphate, Sodium pyrophosphate or potassium pyrophosphate; tetra-substituted (preferably all alkyl) phosphonium, 7-rusonium and stibonium hydro;
:There is I oxide.

The photopolymerized K, 1 acid can be easily removed, if desired, by immersion in a heated aqueous strong alkaline solution, a known proprietary stripping recipe.

The present invention will be explained in more detail by the following examples.

EXAMPLE 1 The following solution was applied to a 1 mil thick polyester film and dried in a hot air stream of a GE-1500 watt dryer for 2 hours.
Dry for 0 minutes. The dry thickness of the receptive layer was approximately 1 mil. The dry layer was covered with a 1 mil thick polyethylene film.

The solutions have the compositions of the present invention, and Solution B does not contain any comparative examples.

Crime a) 50% styrene, 20% methyl methacrylate, 1
Copolymer consisting of 0% ethyl acrylate-I and 20% methacrylic acid; viscosity (measured with 40% methyl ethyl ketone solution) 4500c, ps25°c
40.0% b) Ethoxylated bisphenol Δ diacrylate I *
14.0 g C) Tetraethylene glycol diacrylate-1.7.0 g d) Hensiphenone 2.25 g
e>4.4'-bis-(dimethylamino)hensphenone 0.30 gf) Hydroquinone 0.03 gg) Benzotriazole 0.12 gh) Dyes
0.07 gi) J
4-'X4-)b))-1-7210,0"
1* SR-349, Startomer Indu
Trade name of the jetoxylated compound from Stries: a) Copolymer of 75% styrene, 25% methacrylic acid;
Viscosity (measured in 40% methyl ethyl ketone solution) 1
000cps 40. Ogb) Trimethylolpropane triacrylate 14.0 g C) Tetraethylene glycol diacrylate 7, Og d)) Lyethylene glycol diacetate 1,02 g e) Tricresyl phosphate 2.28 gf
) Benzophenone 2.25 gg
>4.4'--bis-(dimethylamino)benzophenone 0.30 gh)2. ．．
2'-methylene-bis-(4-ethyl-6tert-butylphenol) 0.30 gj) Benzotriazole 0.15 gj) Dye
0.07 gk) Methyl Ethyl Ketone 210.0 g Copper coated epoxy glass fiber board is scrubbed with a cleanser, wiped and rinsed thoroughly with water.

It is then immersed in a 12% aqueous hydrochloric acid solution for 20 seconds, rinsed with water and dried with a stream of air.

The polyethylene cover sheet is removed and a bare resist coating with a polyester support is laminated so that the clean copper surface meets the photopolymerizable layer. Bonding was accomplished using a rubber coated roller at a speed of 2 feet I-7 minutes at 250 DEG F. and a contact pressure of 3 bolts/in@2. Copper coated board covered with polyester film, 400 vaso I.5
A 0 amp mercury lamp (12 inch distance) was used to expose through the high contrast 1 to last transparent film for 30 seconds.

The polyester (polyethylene terephthalate) support film is pulled aside and the exposed resist layer is developed by stirring in a tray with a 1.5% to 1.5% aqueous solution of caustic soda containing a small amount of surfactant.

Stirring time is about 1 minute. After stirring, wash with water. This development method was satisfactory for both solution A and solution B.

After development, the exposed copper surface was prepared by immersing the board in a 20% ammonium persulfate bath for 30 seconds, rinsing with water, immersing it in a 20% hydrochloric acid solution for 30 seconds, rinsing with water, and drying with a stream of air. Washed. The cleaned board was plated for 45 minutes at 30 amps/ft2 in a copper pyrophosphate plating bath at 55°C. Both resists protected the underlying copper surface from the components of the copper pyrophosphate plating bath.

The main difference between the two compositions is the solubility? Since V and B use a film-forming polymeric binder that is brittle and has poor flexibility, an external plasticizer (component (C) fdl melt) is used to impart sufficient flexibility to the photosensitive resist film formed. Solution A requires the addition of B), whereas solution A has the advantage that the copolymer is internally plastic and is a well-improved film-forming material. This copolymer has excellent drying tolerance, integrity (film tack) and resistance to cold flow or creep under static loading.

The flexibility of the films formed from the two solutions was determined by the test method described above by removing the polyethylene sheet from the sandwich strip, packing it into a ball, removing it and stretching it.

Flexibility testing was also done by drying in a forced convection oven for 10 minutes at 1800F? This was also carried out on the films consisting of Yongya A and B. This test method is for determining the drying latitude of photopolymerizable resist films.

Good drying latitude is essential for commercial resist films. Products made from such resists have good shelf life because their flexibility is not affected by residual solvent.

The following table shows that the two films formed from Solutions A and B have significant differences in flexibility, surface tack, and drying latitude.

Fire cold flow or plastic creep is a significant problem for dry resist films. Dried resist films are sold in rolls of various lengths and widths. A certain amount of tension is applied to these rolls. This is to reduce left overlapping and misalignment between layers.

However, this tension induces plastic creep. The effect of cold flow is edge melting or edge fusing of successive layers. This fusing requires some removal of the photopolymerizable layer from the polyester substrate before it can be unrolled, and it also creates pinholes and large discontinuities in the dried film. In a resist in which such a phenomenon occurs, polymerization does not occur upon exposure to light at the peeled portion, and the printed circuit conductor is cut at the pinhole portion, which is a drawback that is unacceptable to consumers.

Cold flow is particularly noticeable in known dry resist films formed from aqueous solutions.

A typical example is the Solution B composition. The cause is that the binder resin contains a large proportion (usually 20-25%) of carboxylic acids containing chain segments. These segments make the film brittle. The external plasticizer makes the film flexible, but leads to increased surface tackiness and severe creep. Solution A does not suffer from such drawbacks since it forms part of the skeleton of the binder polymer of the plastic component.

The rolled dry film rolls were stored and tested using the cold flow test method described above. Under these conditions, a 2 mil thick dry photoresist film of Solution B composition exhibited significant cold flow in two weeks and the wound roll became unsaleable after one month of storage.

On the other hand, films made from coatings of solution A had no edge melting and no internal pinhole formation after 7 months of storage.

The results using the SWORD hardness test are shown below.

Photographs of the exposed experimental films were compared to photographs of resist films possessing known acceptable cold flow properties. The film thickness in solution showed significantly less wire scale than the solution B film.

This indicates that the film in solution has little bleeding at the edges.

EXAMPLE 2 The following x,l paraboloids are made and applied to a 1 mil thick polyester film, dried to a thickness of about 1 mil by the method described in Example 1, and coated with polyethylene. .

Na- a) 50% styrene, 20% methyl methacrylate, 1
Copolymer of 0% ethyl acrylate and 20% methacrylic acid; viscosity (measured in 40% methyl ethyl ketone solution) 45
00cps 40. Ogb) l ~ Rimethylolpropane triacrylate (・13.33g C) Tetraethylene glycol diacrylate 6, 67
g d) Benzophenone 2.25 g
a) 4.4'-His-(dimethylamino)-hensiphenone 0.30 gf)2.
2'-methylene-bis-(4-ethyl-5-tert-
butylphenol) 0.3 (Igg) hensitriazole 0.10 gh) dye
0.07 gI) Methyl Ethyl Ketone 210.0 g Copper coated epoxy fiberglass pods are cleaned and laminated with the above composition.

The target board is a laminate of films made with the composition of Solution B of Example 1. Each board was exposed, developed, and plated in a copper pyrophosphate bath as described in Example 1. Both resist films were sloppily plated in a heated alkaline plating bath.

In Example 2, the physical characteristics of the new resist film
1 shows how properties change depending on the monomer components.

Solution C: Trimethylolpropane triacrylate-I. is used instead of ethoxylated bisphenol-A diacrylate (solution A). This conversion has little effect on the flexibility and drying latitude of the photopolymerizable resist film. However, in terms of sword hardness, it is reduced as shown in Table C.

Rolls made from the surface dissolved Na,C composition were coated to a thickness of 2 mils and tested for cold flow by the method of Example 1. Its behavior is that solution B
were superior to those made from compositions of

Example 3 The following composition was made and deposited on a polyester film to a thickness of 1
It was coated on a mill, dried as described in Example 1 to a thickness of about 1 mil, and coated with polyethylene.

1 use a) 40% styrene, 5% methyl methacrylate, 25
Copolymer of % ethyl acrylate, 30% methacrylic acid; viscosity (measured in 40% methacrylate solution) 580
0cps 40. Ogb)) Limethylolpropane triacrylate 14, 0 g C) Tetraethylene glycol diacrylate 7, Og d) Benzophenone 1.50 g
e) 4.4'-bis-(dimethylamino)-hensiphenone 0.20 gf)2.
2'-methylene-bis-(4-ethyl-5-tert-
Butylphenol) 0.30 gg)) Lyltriazole 0.04 gh) Benzotriazole 0.12 gi) Dye
0.06 gj) Methyl ethyl ketone 210.0 gk) Methyl cellosolve 10.5 g Copper-coated epoxy fiberglass pods were cleaned, laminated with the above film and exposed as in Example 1. The unexposed portion of the film was placed in a tray containing a 1.5% aqueous sodium carbonate solution for 30 to 30 minutes.
Stir for 60 seconds and rinse. The obtained board was heated to 45° Baume of 2nd chloride. Yong? Etching with Fj-,
m, dried. The resist was removed by soaking in 3% caustic soda solution at 130°F for 2 minutes. The resulting board was a good quality printed circuit board. The 1 mil photosensitive film has good flexibility and drying tolerance and a SWORD hardness of 1.
It was 2-14.

Example 4 Copper cladding) ■-- Schiff iber glass pode Example 1
Washed and dried as follows. This board was laminated with a resist film of the following solution to a thickness of 1 mil.

? Liquid E a) Copolymer of 47.5% styrene, 20% methyl methacrylate, 10% acrylonitrile, 22.5% methacrylic acid; Viscosity (measured in 38% notylethyl ketone solution) 3700 cps 40. Ogb) I.Samethylolpropane 1-lyacrylate-1.] 4. Og C) Tetraethylene glycol diacrylate-1/7.0
g d) Hensiphenon 2.25 g
e) 4.4'-bis-(dimethylamino)-hensiphenone 0.30 gf)2.
2'-methylene-bis-(4-ethyl-5-tert-
Butylphenol) 0.30 gg) Benzo 1-lyazole O, 15gh) Dye
0.07 gi) Methyl ethyl ketone 210.0 g Laminated board is irradiated with the chemically active radiation described in Example 1.
Remove the unexposed BB by stirring the board and an aqueous solution containing 21% sodium phosphate and a small amount of surfactant in a tray for 1 minute.

(2) The flexibility and drying latitude of the photosensitive film of the mill were good, the surface of the insulating paint was non-tacky and the SWORD hardness was 16 to I8.

The 2% trisodium phosphate developed boards were further cleaned as in Example 1 and plated in a copper birophosphate plating bath at 55 DEG C. for 45 minutes at 30 amps/rt@2.

The results were excellent.

Example 5 The photopolymerizable solution A of Example 1 was coated onto zinc, magnesium, and copper printed boards. It was dried with warm air to a thickness of about 1 mil, then a dilute solution of polyvinyl alcohol was applied and dried. The water-soluble polymer formed a thin protective film against oxygen.

These sensitive metal plates can now be stored for a considerable period of time.

The unexposed photosensitive layer and the water-soluble Tosopco-1 were simultaneously developed by exposure to a chemically activated lamp through a suitable negative to form a metal plate for etching. The photopolymerized images showed poor resistance to even the harshest etching agents commonly used in the manufacture of printed metal boards. These resists showed good resistance to conventional etching agents, ie, ferric chloride, nitric acid, film formers, and banking agents that are commonly added to control the shape of the etch.

Example 6 A similar run was carried out in Example 5 except that a 1 mil polyester film was used as the protective layer instead of the water-soluble polymer. After exposure to a chemically activated lamp, the protective layer was removed before development with aqueous alkaline solution. Images photopolymerized as in Example 5 showed remarkable resistance to strong etching of printed boards.

Example 7 Solution A of Example 1 was applied to a polyester film at a thickness of 1 mil, air dried, and covered with a 1 mil thick polyethylene film. These Zandwich three-layer films are made of 1. Before use, the polyethylene cover film is removed and the photosensitive layer is bonded and laminated to the metal plate of Example 5. Exposure to a chemically activated lamp removes the protective polyester layer. It is removed and developed in an alkaline solution.As in Example 5, the photopolymerized image showed poor resistance to strong etching of the printed board.

Example 8 The solution of Example 1 is coated onto a thin aluminum plate according to conventional offset lithography techniques as described in Example 5.6.7. Exposure to a chemically activated lamp and development using an alkaline solution were performed. The photopolymerized image was excellent as an ink receiver.

It also showed excellent frictional resistance. The plate of this example was used with good results in offset lithography.

Example 9 Solution A of Example 1 was applied onto a woven, mesoche-like substrate as shown in Example 5.6.7.

Exposure to a chemically activated lamp and development with an alkaline aqueous solution were performed. The photopolymerized image showed an excellent mask. This application is also effective for silk screen printing.

Test Example Six types of dry film photoresists 1 to 1 were prepared according to the formulations shown below. The meanings of the abbreviations are as follows.

V-849-44: n-hexyl methacrylate/styrene/methyl methacrylate/methacrylic acid], 1.3/101 57.7/21 (37,56% MEK (methyl ethyl ketone) solution) SB-983-7: Styrene/n-hexyl methacrylate/methacrylic acid - 10/60/30 (36% MEK? solution) P-507 Styrene/n-hexyl methacrylate/ethyl acrylate/methacrylic acid - 50/20/10/20 (40% MEK solution) l5
M-948-45: The following formula T: Expressing h ru” TMHD
” -E/Mama- Film level 1 Ingredients Weight 5B-983-7 (39.0g, 100χ polymer)
108.3g 5M-948-45TMIID monomer 33.6g Tetraethylene glycol dimethac 1 route
0.9g Michler's Ketone
0.3g benzophenone
Enough ME to coat 2.25g crystal violet base 0.07g
K Film floor 2 WAV-849-44 (40, Og, 100χ poly"?
-) 106.5 g 5M-948-457MHD monomer 22.4 g Te) ethylene glycol dimethacrylate
0.6g Michler's Ketone
0.3g benzophenone
2.25g crystal violet base
Enough MEK film to coat 0.07g 1lh3 P-50 polymer (40,0,g, solids) lo
o, og trimethy ■-lube ■ pan triacrylate
13.33g
3g tetraethylene bricoat thick relay
6.67g Benzophenone 2.25g Michilazke I.N 0.3g2.
2-Methylene-bis-(4-ethyB-6-tert-butylphenol) 0.3g Benzotriazole 0.1g Crystal violet base 0.07g Film No. 4 P-50 polymer (40.0g, solid content) 100
．． 0g5M-948-457MHD Monomer
33.6g Tetraethylene glyco-11 Dimethac 1 route (SR-209)
0.9g Michler's Ketone
0.3g benzophenone
2.25g crystal violet base
0.07g film size 5 P-50 polymer (40.0g, solid content) 100
．． 0g5M-948-45TMlln monomer
22.4 g tetraethylene gelicol dimethacrylate-10,6.

Michler's Ketone 0.38 Henzphenone 2.25g
Crystal Violet 1~Base 0.07g
, 6 WAV-849-44 (40.0g, solid content)
106.5g trimethy n-+L-pan triacrylate
13.33g Tetraethylene Glyco-IL・Thiata 1 Roux) 6.
67g benzophenone 2
．． 25g Michler's Ketone 0
．． 3t: 2.2-medylene bis-(4-ethyl-6-
tert-butylphenol) 0.3 g benzotriazole 0.1 g crystal violet base 0.07 g The above composition was coated on a 1 mil (0.0254 m) polyester film support to a dry thickness of 2 mil (0.0508 mm). Then, MEK was evaporated by drying with a forced hot air heater for 30 minutes. A cover sheet of 1 mil polyethylene film was then applied.

A sample of the dried composition was laminated to a copper coated epoxy glass fiber circuit board using a Dynachem Model 120 laminator with a commercially available Lam 1 size. The lamination speed was 3 to 5 feet/min, and the heating (113℃±5.6℃
) Laminated using a pressure roller.

Next, this laminate was exposed to 55 to 60 millijoules of ultraviolet light using Scanex ■ manufactured by Colite Corporation.
Exposure through a negative transparency. It was then developed with a 1% aqueous sodium carbonate solution (38°C), thoroughly etched in a 45° Baume ferric chloride solution to remove the exposed copper, and heated (57°C) with 3% helium hydroxide. The photopolymerized portion was peeled off by contact with the solution.
1 During and after the above operation,
Six films were evaluated as shown in Table I.

The test conditions for each characteristic are as follows.

1. Development All laminated panels were passed through a Chemcasso model 547 spray kit developer containing 1% aqueous sodium carbonate solution. All six laminates were developed within an acceptable standard time of less than 1 minute.

2. Plating In the plating process, all laminated panels are immersed in a 20% ammonium persulfate bath for 30 seconds, rinsed with deionized water,
Precleaning was performed by immersion in 0% IIcI aqueous solution for 30 seconds, rinsing with deionized water, and then drying with an air jet. This washed laminate was treated under the following conditions.

+a) Copper sulfate: 22.5 g of copper/123°C, 45 minutes,
20 amps/sq ft (b) Copper pyrophosphate: Copper 22.5g/j2.49°C
, 45 minutes, 30 amps/square foot (C) Tin/Lead: 18 g/n tin, 12 g/n lead, 350 g/β borofluoric acid, 23°C, 15 minutes, 15 amps/ft.
3 sq. ft. Etching This alkaline etchant was obtained from Southern California Chemical Company.

This etching agent was a type A alkaline etching agent manufactured by this company, and the processing was carried out at pH 8.6 and 49°C. Copper chloride etchant was obtained from Oxford Systems. This stuff is 23.
It contained 2 ounces of copper and was processed at 49°C.

4. Creep 2 mil thick film strip (1 inch x 5 inch)
One end was firmly grasped and the other end was grasped and allowed to hang from the member. A 14 g weight was attached to the other end of this lip. The film was held at 23°C for 10 minutes. The percentage elongation from the original length of the strip was measured. This creep test is recognized in the field of dry film technology as an accelerated test that correlates with the long-term cold flow properties of dry film resists. That is, it is expected that the higher the elongation rate, the higher the cold flow due to stress deformation of the film compressed into a roll, which would normally cause bone LJ.

The following table shows film positive and U.S. Patent No. 3,390,865
(Faust patent) and the corresponding relationship with the embodiments of the present invention.

Film positive relationship 1, Faust Example 4 (contains 10% styrene) 2, Faust I Example 9 (styrene 10%)
% content) 3. Example 2 of the present invention (containing 50% styrene) 4. In Faust Example 4, the binder of Example 2 of the present invention (containing 50% styrene) was used 1
5. In Example 9 of Faust, the binder of Example 2 of the present invention (containing 50% styrene) was used6. In Example 2 of the present invention, the binder of Example 9 of Faust (containing 10% styrene) The data from the above tests show that the styrene content of the present invention is critical and far superior to the low styrene content disclosed in the Faust patent.

That is: 1. The results of the creep test clearly show that increasing the styrene content improves the cold flow resistance. For example, film level 5 is film level 2.
The only difference between the two is the styrene content. This indicates that increasing the styrene content in the Faust compositions beyond the range taught or suggested improves cold flow resistance. This fact is
This should clearly indicate the patentability of the present invention. This also applies when comparing films 5 and 6. That is, the composition of the Faust patent (Film 11k15) in which the 50% styrene-containing binder was replaced is superior to the composition of the present invention (Film 6) in which the styrene content of the binder was reduced to 10%. Also, film No. 3 is an example of the present invention, but it is clearly superior to any other film. This is the fact that best demonstrates the effect of the present invention.

2. The stability of these compositions and their suitability for use as dry film resists were determined from the results of testing six different films.
It can be seen that the order is as follows.

Order Film block

Claims (3)

[Claims] (1) (A) A non-gaseous addition polymerizable substance with a boiling point of 100°C or higher; an addition polymerization initiator system that generates free radicals;
The first monomer of the copolymer is a styrene type material, the second monomer is an acrylate type material, and the third monomer is an unsaturated carboxyl group-containing monomer having 3 to 15 carbon atoms. wherein the ratio of each monomer to the unsaturated carboxyl group-containing monomer of the copolymer component is such that the flexibility of the photopolymerizable composition is imparted without an external plasticizer, and (B) exposing said photopolymerizable layer to chemically actinic radiation; (C) A method for producing a photoresist, which comprises washing the layer with a dilute aqueous alkaline solution to remove unexposed areas of the photopolymerizable layer. 2. A method according to claim 1, which comprises applying the photopolymerizable layer to a substrate and removing by washing the portions of the substrate covered with the red-exposed portions of the photopolymerizable layer. 3. The method of claim 2, further comprising treating the photopolymerizable layer to permanently modify the uncoated portions of the substrate after the photopolymerizable layer has been cleaned.