JPH03134669A - Aqueous developable photo-resist containing thiol compound - Google Patents

Abstract

PURPOSE: To obtain the photoresist adapted to form a printed circuit plate by incorporating a photopolymerization initiator and a specified photoreactive monomer or oligomer and a specified thiol compound each in a specified amount in a polymer binder having carboxyl groups. CONSTITUTION: The photoresist composition suitable for manufacture of the printed circuit plate and developable in an aqueous alkaline developing solution comprises the polymer binder having carboxyl groups and this binder contains the photopolymerization initiator in an amount of 1-15weight% of the binder, and the photoreactive monomer having at least 2 ethylenically unsaturated double bonds or its oligomer in an amount of 20-100weight%, and further the thiol compound of formula 1 soluble or dispersible in an aqueous solution of weak alkali in an amount of 0.05-5weight%, and in formula I, each of (a) and (b) is an integer of >=1, R is an organic group having a molecular weight of <500; and X is a group having a carboxyl group or a hydrophilic organic polymer segment having <100 repeating units.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application of the Invention] The present invention relates to dry film photoresist compositions used in the fabrication of printed circuit boards, particularly photoresist films that are developable in aqueous alkaline solutions. The present invention relates to a composition for forming a composition.

[Prior Art and Problems to be Solved by the Invention] Water-based, alkaline-developable dry film photoresists are widely used in the fabrication of printed circuit boards because they are less environmentally polluting than their organic solvent-developable counterparts. Uke is now accepted. A typical method for using aqueous, alkaline-developable, negative-working photoresists in the fabrication of printed circuit boards is to laminate a photoresist film to a copper-clad substrate and apply the photoresist film to the artwork or image. The unexposed portions of the photoresist layer are removed by an aqueous solution of weak alkaline, leaving the exposed portions of the layer or the photoresist image on the copper-clad substrate; The process involves etching the exposed portions of the substrate, thus leaving portions of the copper covered by the photoresist image, and then removing the photoresist image from the substrate with a relatively strong aqueous alkaline solution.

Generally, dry film photoresists consist of three layers. The first layer is a clear polyester protective layer with a thickness of about 25-cm, the second layer is a photosensitive layer with a thickness of about 25-75-cm, and the third layer is usually about It is a polyethylene film having a thickness of 25-. Aqueous alkaline developable dry film negative working photoresists are primarily carboxyl-containing polymeric binders, monomers or oligomers with ethylenically unsaturated functional groups, which generate free radicals upon exposure to actinic radiation. It is known to consist of an initiator and additives such as dyes, plasticizers and adhesion promoters.

Binders containing carboxyl groups typically include acrylic polymers, such as copolymers of methacrylic acid or acrylic acid.

Examples of these polymers are described in U.S. Patent No. 4.535.052.
No. 4,234,675. Basically, the binder should be soluble in aqueous alkaline solutions and capable of providing a photoresist composition with fast solubility during the development step.

It is generally accepted that adhesion of photoresist patterns to copper surfaces is important, especially when fine line patterning is involved. Therefore, small amounts of adhesion promoters are incorporated into photoresist compositions. A typical example is U.S. Pat. No. 3,758.
Silane compounds such as those disclosed in U.S. Pat. No. 3,758,306, U.S. Pat.
2-mercaptobenzothiazoles as disclosed in 339.527 and 4.230.790.

However, due to the strong coupling reaction between the silane compound and the copper surface, the difficulty in completely rinsing off the unexposed photoresist leaves photoresist residue or scum on the copper surface and creates problems in etching and plating. bring about things.

Additionally, 2-mercaptobenzothiazole, a thiol-containing compound, has moderate reactivity with scrap copper surfaces and often leaves a thin film of residual material on the copper surface in unexposed areas after Bacoon development. Therefore, problems similar to those of silane compounds are encountered. Additionally, 2-mercaptobenzothiazole can react with copper to form complex compounds that can cause contamination of etching and plating solutions, as evidenced by the reddish color on the copper substrate.

Indeed, the inclusion of compounds containing small amounts of thiols is known to promote photoinitiated free radical growth reactions through chain transfer reactions, making it useful in photosensitive compositions. As taught in many publications and patents, there are photosensitive compositions that include many thiol compounds. These compositions are
Exposure to ultraviolet light, sometimes in combination with thermal energy, induces an addition reaction between the thiol group and the ethylenically unsaturated double bond. Generally, the polythiols and polyenes that undergo the addition reaction have substantially equimolar functional groups and can be cured with or without a photoinitiator.

Typical examples are U.S. Patent Nos. 3,976,553, 3,966,794, and 3,908.
Specification No. 039, Specification No. 4.008.341, Specification No. 4.230.740, Specification No. 3.843.57
Specification No. 2, Specification No. 3.904.499, No. 3
．． No. 936.530 and No. 3.660.08
Seen in Specification No. 8. These photocurable compositions are primarily useful for moldings, coatings, adhesives and sealants; only a few of them are used as organic solvent developable photoresists. The polythiols mainly used are commercially available pentaerythritol tetra (mercaptoacetate), pentaerythritol tetrakis (β-mercaptopropionate) or trimethylolpropane tris (3-mercaptopropionate).

The polyfunctional thiol compounds described above have relatively high molecular weights so that when large amounts are used in compositions of this type, typical mercaptan odor levels can be kept within acceptable limits. These polythiols are different from the thiol compounds disclosed in this invention, and none of them are suitable for use in this invention.

Generally, photoresist films containing polythiols as described above are prepared by spraying the photoresist film with a jet of an aqueous solution of potassium hydroxide or sodium hydroxide in a method of stripping the photoresist film from protected copper in a stripper. It has the disadvantage that the film does not disintegrate into dispersed fine particles but separates from the copper in whole or in large pieces when it is washed. The resulting large pieces of film can block the nozzles of the spray jet when the used stripping solution is recycled to the spray jet for reuse.

The polyenes used in the above patents have primarily allyl and vinyl functionality. Polyenes with acrylic functional groups are unsuitable for the compositions described in the above-mentioned patents due to their relatively high reactivity toward polythiols; For liquid compositions containing a high content of polythiol, as is the case with most compositions, stability problems arise.

[Means to solve the problem]

It is an object of the present invention to provide an aqueous solution which enhances the adhesion between the composition and the surface of a copper-clad substrate, yet advantageously leaves no residue or scum from the composition on the copper surface after development in a weakly alkaline solution. An object of the present invention is to provide an alkali-developable photoresist composition. Additionally, the exposed photoresist film is easily removed from the copper surface and dissociates into small pieces in alkaline stripping solutions, thereby posing the risk of blocking the spray nozzles of strippers commonly used in the printed circuit board industry. Can be minimized.

The present invention is an aqueous alkaline developable photoresist composition comprising: a) a polymeric binder containing carboxyl groups; b) 1 to 15% by weight of a photoinitiator based on the binder; ) 20 to 100% by weight based on the above binder,
a photoreactive monomer or oligomer containing in the molecule at least two ethylenically unsaturated double bonds; and d) from 0.05 to 5% by weight, based on the abovementioned binder.
Formula (x+TR-(S)l).

(wherein a and b are integers of 1 or more, R is an organic group with a molecular weight of less than 500, and X is a group containing a carboxyl group or a hydrophilic organic polymer segment having less than 100 repeating units) An aqueous alkaline developable photoresist composition comprising a thiol compound represented by The thiol compounds used in the present invention are different from the thiol compounds described in the above patents;
Will be described later.

The polymeric binder used in the present invention is a film-forming thermoplastic polymer or a mixture of these thermoplastic polymers that is soluble in aqueous alkaline solutions. The preferred weight average molecular weight of the binder is 10.000 to 1,000.000.
range, and the acid value of the binder is greater than 70. Polymers suitable as binders are obtained by copolymerization of monomers consisting of at least the following components: acrylic acid or methacrylic acid and other copolymerizable monomers such as alkyl acrylates or alkyl methacrylates. It is a copolymer. Suitable alkyl acrylates are hexyl acrylate, butyl acrylate, ethyl acrylate and methyl acrylate. Suitable alkyl methacrylates include hexyl methacrylate, butyl methacrylate,
They are ethyl methacrylate and methyl methacrylate. Other suitable comonomers used to form the binder are benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, butoxyethyl acrylate, butoxyethyl methacrylate, 2-hydroxypropyl acrylate and 2-hydroxypropyl methacrylate.

Further suitable copolymerizable monomers are β-carboxyethyl acrylate, phthalic acid acrylate, and phthalic acid methacrylate. If necessary, any one of the last three monomers can replace the role of acrylic acid or methacrylic acid in the aforementioned components of the binder polymer, since they simultaneously contain carboxylic acid groups.

The binder is a composition comprising the following components (a) to (c); (a) acrylic acid, methacrylic acid, β-carboxyethyl acrylate, in an amount of 15 to 45 mol% based on the total number of moles of the composition; a monomer or mixture of monomers selected from phthalic acid acrylate and phthalic acid methacrylate; (b) methyl methacrylate, hydroxyethyl methacrylate; A monomer selected from ethyl acrylate, ethyl methacrylate, butyl acrylate, and butyl methacrylate or a mixture of these monomers ζ and (c) 0 to 10 mol% based on the total number of moles of the composition
, benzyl acrylate, benzyl methacrylate,
It is preferably produced by copolymerization of monomers or mixtures of these monomers selected from phenoxyethyl acrylate and phenoxyethyl methacrylate.

Other preferred binders may be esterified styrene-maleic anhydride copolymers.

A further preferred binder may be a mixture of the two preferred binders mentioned above.

Photoreactive monomers or oligomers suitable for the present invention include at least two
Commercially available photosensitive monomers or oligomers containing reactive functional groups such as butanediol diacrylate, hexanediol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, butanediol diacrylate, alkoxylated aliphatic diacrylates and polyethoxylated bisphenol A diacrylates, aliphatic and aromatic urethane diacrylates, and epoxy diacrylates of various molecular weights, trimethylolpropane triacrylate and its ethoxylated transparent conductors, Pentaerythritol triacrylate, alkoxylated aliphatic tri- or tetra-acrylate, dipentaerythritol polyacrylate. Also, a suitable component is the methacrylic equivalent of the polyacrylate described above. The amount of photoreactive monomer or oligomer used is from 20 to 100% by weight, based on the binder.

Suitable photoinitiators for use in the present invention include ketones such as benzophenone, acetophenone, benzylbenzocyclobutanone, etc.; derivatives of acryloin such as benzoin methyl ether, benzoin ethyl ether, etc.; Michler's ketone, dimethoxyacetophenone, jetoxyacetophenone, Substituted benzophenones such as halogenated benzophenones; quinones such as benzoquinone, anthraquinone, phenanthraquinone, etc.; substituted polynuclear bosonones such as chloroanthraquinone, methylanthraquinone, octa-methylanthraquinone, naphthoquinone, dichloro-naphthoquinone, etc. One or a mixture of the above-mentioned photoinitiators can be used in the present invention. A suitable amount of photoinitiator used may be from 0.1 to 15% by weight, based on the binder.

The thiol compound suitable for the present invention has hydrophilicity and has the formula ('i+TR(SH)b) (wherein a and b are integers of 1 or more, and X is a group containing a carboxyl group or a low molecular weight and R is an organic group, preferably an aliphatic segment, having a molecular weight of less than 500.Thus, thiol compounds suitable for the present invention include carboxyl groups. and a thiol compound containing a hydrophilic polymer segment.

Easily commercially available thiol compounds containing a carboxyl group include, for example, mercaptoacetic acid, α-mercaptopropionic acid, β-mercaptopropionic acid, 4-mercaptobutyric acid, mercaptoundecylic acid, 0-mercaptobenzoic acid and p -Mercaptobenzoic acid. However, due to their high volatility, the first three thiol compounds mentioned above have limited use in the present invention.

Other suitable carboxyl group-containing thiol compounds are thiol compounds obtained by addition reaction of a carboxyl group-containing compound with hydrogen sulfide or a polythiol compound having at least two reactive thiol groups.

Alkenes may contain one or two ethylenically unsaturated double bonds. However, alkenes containing one ethylenically unsaturated double bond are preferred since they avoid gelation during addition reactions. Preferably, the number of ethylenically unsaturated double bonds per polythiol compound is at least one unit less than the number of thiol functional groups in the polythiol molecules in the reaction mixture.

Suitable polythiol compounds for the above addition reaction include ethanediobenhexamethylene dithionopedeyl dithiol, toluene-2,4-dithionopeethylene glycol bis(thioglycolate), and ethylene glycol bis(β-mercapto-propionate). , trimethylolpropane tris (thioglycolate), trimethylolpropane tris (β-mercapto-propionate), pentaerythritol tetrakis (thioglycolate) and polypropylene ether glycol bis (
β-mercapto-propionate).

Alkenes suitable for the above addition reaction include acrylic acid, propionic acid, crotonic acid, 3-butenoic acid, methacrylic acid,
2-pentenoic acid, 3-methylcrotonic acid, 4-pentenoic acid, tiglic acid, 4-methyl-2-pentenoic acid, 2-hexene L 3-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 2-octene acid, 3-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 2-decenoic acid, 2-undecenoic acid, 1
Alkenes having one or more carboxyl groups, such as 0-undecenoic acid, trans-2-dodecenoic acid, 2-tridecenoic acid, and 2-hexadenoic acid. Other suitable alkenes are fumaric acid, maleic acid, citraconic acid, itaconic acid, mesaconic acid, trans-2-butene-1,4
- dicarboxylic acids, traumatic acids, etc.

Yet another suitable thiol compound containing a carboxyl group is a thiol compound obtained by an esterification reaction between a polythiol and a cyclic acid anhydride.

Suitable cyclic acid anhydrides include succinic anhydride, fucuric anhydride, and the like. The number of thiol functional groups on the polythiol should be at least one unit greater than the number of acid anhydrides per polythiol molecule in the reaction mixture.

The thiol compound containing a hydrophilic polymer segment includes at least one thiol group and a hydrophilic polymer segment selected from polyvinyl alkone, polyethylene glycone, and polyvinyl methyl ether. A thiol compound containing a hydrophilic polymer segment is a combination of an alkene containing a hydrophilic polymer segment having at least one ethylenically unsaturated double bond and a polythiol compound having hydrogen sulfide or at least two thiol groups. It may also be a thiol compound obtained by addition reaction. Preferably, the alkene contains one ethylenically unsaturated double bond to avoid gelation during the reaction. The number of thiol functional groups in the polythiol compound should be at least one unit greater than the number of ethylenically unsaturated double bonds per polythiol molecule in the addition reaction mixture.

Suitable alkenes containing hydrophilic polymeric segments are alkenes with segments of polyethylene glycol or polyvinyl methyl ether or polyvinyl alcohol (the number of repeating units being less than 100), such as polyethylene glycol acrylate or polyethylene glycol methacrylate.

Other suitable thiol compounds containing hydrophilic groups are those obtained by addition reaction of water-soluble or water-dispersible aliphatic monoepoxides with hydrogen sulfide or polythiols.

Suitable reaction conditions for the above-mentioned addition or condensation reactions involving polythiol compounds are described in many publications, such as Saul et al.
'The Chemistry of the Thiol Group', edited by Saul Patai.
1ol Group)” (John Wiley &amp;
Sands (John Wiley & 5ons), 19
74) or F. W. Stacey and J. F. Harris, “Organic Reactions (O
13, Chapter 1, Wiley, London 1963. There are many other synthetic routes to the desired thiol structure of the present invention. Therefore, embodiments of the present invention teeth,
It is not limited to the above synthesis method.

The invention is explained in more detail by the following non-limiting examples.

〔Example〕

Example 1 Thiol Compound A was prepared from the following compounds.

Ingredients Itaconic acid amount 7.8g 2,2'-Azobisisobutyronitrile 0.0656
g Hydroquinone 0.0
088 g Methyl ethyl ketone 1
6g Improper Tool 2g The above compound was placed in a sealed glass container and heated to 60°C.

The reaction was stopped when the reaction mixture reached a substantially constant viscosity. The reaction time was approximately 4 hours. Low molecular weight volatiles were removed from the product by room temperature vacuum operation.

The resulting product was soluble in 1% aqueous sodium carbonate solution.

Example 2 Thiol Compound B was prepared from the following compounds.

Ingredients Amount Pentaerythritol Tetra (Mercapto-acetate) 4.32
g Polyethylene glycol methacrylate (manufactured by Intelez Kanbanii) 10.52 g2.2
'-Azobisisobutyroni) IJru 0.0033
g Hydroquinone 0.00
022 g Methyl ethyl ketone 0
．． Put 69 g of the above ingredients into a sealed glass container and add 60 g.
heated to ℃. The reaction was stopped after 2.5 hours. Low molecular weight volatiles were then removed from the product by vacuum. The resulting product was soluble in 1% aqueous sodium carbonate solution. The polyethylene glycol methacrylate used therein had a molecular weight of 526.

Example 3 Thiol Compound C was prepared from the following compounds.

Compound Quantity Pentaerythritol tetra(mercapto-acetate)) 8.64g
2.2'-azobisisobutyronitrile 0.0016
4 g hydroquinone 0.
00012 g methyl ethyl ketone
Place 0.35 g of the above ingredients in a sealed glass container,
Heated to 60°C. The reaction time was over 2.5 hours until the viscosity did not increase further. Volatiles were removed from the product under reduced pressure. The resulting product was soluble in 1% aqueous sodium carbonate solution.

Example 4 Thiol compounds were prepared from the following compounds.

Compound Amount Pentaerythritol Tetra (Mercapto-acetate) 4.32
g polyethylene glycol methacrylate) 5.26
g Photomer 6173 2.
48 g2.2'-Azobisisobutyronitrile 0.
00328 g Hydroquinone
0.00022 g methyl ethyl ketone
0.69 g The experimental procedure for this example was similar to that of Example 2.

Example 5 Ingredients Benzyl dimethyl ketul 0.5 g Michler's ketone 0.001 g Trimethylolpropane triacrylate 1,75
g Bisphenol A diacrylate for tetraethoxyl 1 g Urethane acrylate 0.5 g Blue 603 (dye manufactured by Orient Company) 0.0075
g methoxyhydroquinone ether 0.02
g The above composition and 0.03 g of Thiol Compound A were dissolved in a suitable solvent and thoroughly blended. The blended photosensitive composition is 20cm x 2 with a doctor blade.
It was applied to a 5 cm polyethylene terephthalate film. The thickness of the applied film after drying was approximately 30 microns. The photosensitive film was heated to 103° C. and then adhered by roller laminator to the surface of a copper substrate that had been precleaned in a cleaning solution to remove oil and dirt. UV printer (type ORCI (M1) with 3klll lamp)
11532) was used to expose the sample with an exposure energy of 70 [TIJ/cm2]. The artwork used during exposure had line and spacing patterns of different widths. The photoresist film is coated with a circuit
Developed in a 1% aqueous sodium carbonate solution for about 140 seconds with a nozzle spray developer manufactured by Rcuitape.

Example 6 (comparative example) except that the thiol compound was excluded from the composition of Example 5.
The experiment was carried out in the same manner as described in Example 5.

Example 7 (Comparative Example) Thiol compound A was mixed with 0.0% pentaerythritol tetra (mercaptoacetate), which is insoluble in an alkaline aqueous solution.
The experiment was carried out in the same manner as described in Example 5, except that 02g was substituted.

Example 8 (Comparative Example) An experiment was carried out in the same manner as described in Example 5, except that thiol compound A was replaced with 0.015 g of mercaptobenzothiazole, which is insoluble in aqueous alkaline solution.

Tests were conducted to determine the properties of the samples obtained from the experiments of Examples 5, 6.7 and 8. A scum test commonly used by printed circuit manufacturers was used. In the scum test, the copper surface not covered by the developed photoresist pattern is flash etched and the flash etched copper surface is then oxidized to obtain a dark color.

Make visible the shiny copper surface or so-called scum covered by residual photoresist. The scum test used in this example included the following sequential steps: acid wash followed by water rinse, flash etching in 5% aqueous sodium persulfate, followed by water rinse, then dark etching in aqueous cupric chloride. oxidation, followed by water rinsing. Excluding water rinsing, place the developed sample plate in the etching solution for about 1 hour.
It was immersed for 0 seconds.

A reflection microscope was used to determine whether the samples exhibited the brightness of the original surface of the copper, which could not be etched due to the scum coating thereon. The results of these tests are shown in Table 1. The results show that the samples of Example 5 produced from compositions containing thiol compounds of the present invention do not form scum, and the samples of Examples 7 and 8 produced from compositions containing thiol compounds insoluble in aqueous alkaline solutions do not scum. It can be seen that a large amount of scum forms on the copper when compared to the sample of Example 6 which does not contain thiol compounds. Therefore, it can be appreciated that if an aqueous alkaline developable photoresist composition contains commonly used thiol compounds that are insoluble in aqueous alkaline solutions, the photoresist film will scum. However, when the above thiol compounds are replaced by the thiol compounds of the present invention, no scum is formed.

Table 1 Example 9 Ingredient amounts (parts by weight) Benzyl dimethyl ketal 10 Trimethylolpropane triacrylate 25 Tetraethoxylated bisphenol A Diacrylate Tetraethylene glycol acrylate B603 (dye manufactured by Orient Company) Michler's ketone 0.15 0.02 The above compound was mixed with Thiol Compound A and applied to a copper substrate. Test samples were prepared as described in Example 5.

Example 10 The experiment for this example was conducted in the same manner as described in Example 9, except that Thiol Compound A was replaced with the same thiol compound.

Example 11 This example was conducted in the same manner as described in Example 9, except that thiol compound C was substituted for thiol compound.

Example 12 This example was conducted in the same manner as described in Example 9, except that Thiol Compound A was replaced by Thiol Compound R.

Samples of Examples 9, 10, 11 and 12 were tested and the results of the tests are shown in Table 2.

Table 2 Example Range of Exposure Adhesion Stripping (
mJ/cm2) (I!Im) (time/particle size)9
40-60 60 55 seconds/ku2
Mark 10 40-70 60 4
8 seconds/<2fnI! 11140～60 60
60 seconds/<2 barrels 1240~60 60
53 seconds/<2 mm In Table 2, exposure range means the exposure energy that produces a resolution of 60 JR lines/70±5 JJs interval. Adhesion was measured on the thinnest lines remaining on the copper (line spacing was 340±15−).

Stripping was measured by immersing the developed plate in a 2% KOH solution at 55-60°C under magnetic stirring. The stripping test results shown in Table 2 are from samples that received 70 mJ/cm2 during image exposure.

Claims (1)

[Scope of Claims] 1. An aqueous alkali-developable photoresist composition comprising at least the following components 1) to 4): 1) a polymeric binder containing a carboxyl group; 2) the above-mentioned binder; 1 to 15% by weight of photopolymerization initiator based on the above binder; 3) 20 to 100% by weight based on the above binder;
a photoreactive monomer or oligomer containing at least two ethylenically unsaturated double bonds; 4) from 0.05 to 5% by weight, based on the above binder;
Formula▲There are mathematical formulas, chemical formulas, tables, etc.▼R-(SH)_b (In the formula, a and b are integers of 1 or more, R is an organic group with a molecular weight of less than 500, and X is a carboxyl group. or a hydrophilic organic polymer segment having less than 100 repeating units. 2. The polymer binder is 10,000 to 1,000,
2. The aqueous, alkaline developable photoresist composition of claim 1 having a weight average molecular weight of 0.000 and an acid number greater than 70. 3. The binder has the following components (a) to (c): (a) 15 to 45 mol% of the group consisting of acrylic acid, methacrylic acid, β-carboxyethyl acrylate, phthalic acid acrylate, and phthalic acid methacrylate; An acrylic monomer containing a carboxyl group or a mixture of acrylic monomers containing a carboxyl group, selected from (b) 55
~85 mol % of a monomer selected from the group consisting of methyl methacrylate, hydroxyethyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and butyl methacrylate, or a mixture of these monomers, and (c) 0 to A copolymer produced by copolymerization of a comonomer comprising 10 mol% of a monomer or a mixture of these monomers selected from the group consisting of benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate and phenoxyethyl methacrylate. The aqueous alkaline developable photoresist composition of claim 1. 4. The aqueous, alkaline developable photoresist composition of claim 1, wherein said binder is an esterified styrene-maleic anhydride copolymer. 5. The aqueous, alkaline developable photoresist composition of claim 1, wherein said binder comprises a mixture of the copolymers of claims 3 and 4. 6. The aqueous alkaline developable photoresist composition of claim 1, wherein the hydrophilic organic polymer segment is a polymer selected from the group consisting of polyvinyl alcohol, polyethylene glycol, and polyvinyl methyl ether. 7. Aqueous alkaline development according to claim 1, wherein the thiol compound is a reaction product from an addition reaction mixture containing a polythiol and an alkene containing a carboxyl group, or a reaction mixture of a polythiol and an alkene containing a hydrophilic segment. Possible photoresist compositions. 8. The aqueous alkaline developable photoresist composition of claim 1, wherein the thiol compound is a reaction product from a condensation reaction mixture comprising a polythiol and a compound comprising a cyclic acid anhydride. 9. The aqueous, alkaline developable photoresist composition of claim 7, wherein said alkene contains one ethylenically unsaturated double bond. 10. -SH in the polythiol of the above addition reaction mixture
8. The aqueous, alkaline developable photoresist composition of claim 7, wherein the number of groups is at least one unit greater than the number of ethylenically unsaturated double bonds per polythiol molecule. 11. The aqueous, alkaline developable photoresist composition of claim 8, wherein the number of -SH groups in said polythiol is at least one unit greater than the number of acid anhydride groups per polythiol molecule. 12. The polythiol mentioned above is ethanediol, hexamethylene dithiol, decamethylene dithiol, toluene-2,4-dithiol, ethylene glycol bis(thioglycolate), ethylene glycol bis(β-mercapto-propionate), trimethylolpropane tris( 9. The polypropylene ether glycol bis(β-mercaptopropionate) is selected from the group consisting of trimethylolpropane tris(thioglycolate), trimethylolpropane tris(β-mercaptopropionate), pentaerythritol tetrakis(thioglycolate) and polypropylene ether glycol bis(β-mercaptopropionate). an aqueous alkaline developable photoresist composition. 13. The carboxyl group-containing alkene is acrylic acid, propionic acid, crotonic acid, 3-butenoic acid, methacrylic acid, 2-pentenoic acid, 3-methylcrotonic acid, 4
-pentenoic acid, tiglic acid, 4-methyl-2-pentenoic acid, 2-hexenoic acid, 3-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 2-octenoic acid, 3-octenoic acid,
2-nonenoic acid, 3-nonenoic acid, 2-decenoic acid, 2-undecenoic acid, 10-undecenoic acid, trans-2-dodecenoic acid, 2-tridecenic acid, 2-hexadecenic acid, fumaric acid, maleic acid, citraconic acid 8. The aqueous alkaline developable photoresist composition of claim 7, wherein the aqueous alkaline developable photoresist composition is selected from the group consisting of , itaconic acid, mesaconic acid, trans-2-butene-1,4-dicarboxylic acid, and traumatic acid. 14. The aqueous, alkaline developable photoresist composition of claim 7, wherein the alkene comprising the hydrophilic segment is selected from the group consisting of polyethylene glycol methacrylate and polyethylene glycol acrylate. 15. The aqueous alkaline developable photoresist composition of claim 8, wherein the acid anhydride-containing compound is selected from the group consisting of succinic anhydride and phthalic anhydride.