WO2007119947A1

WO2007119947A1 - Method of manufacturing metal electrode

Info

Publication number: WO2007119947A1
Application number: PCT/KR2007/001701
Authority: WO
Inventors: Byoung-Kee Kim; Se-Hyung Park; Byrong-Il Lee; Jong-Min Park; Seog-Jeong Song
Original assignee: Kolon Industries, Inc
Priority date: 2006-04-13
Filing date: 2007-04-06
Publication date: 2007-10-25
Also published as: TW200741350A; JP4990966B2; TWI349166B; JP2009533706A

Abstract

Disclosed is a method of manufacturing metal electrode, comprising: ( I ) a step of forming a photoresist layer over the whole surface of a substrate by means of coating or laminating method, then, enabling the whole surface of the substrate with the photoresist layer to successively undergo pre-baking, exposing, developing and post-baking processes to form a metal electrode pattern, so that the photoresist layer remains on any region of the substrate other than a region which has the metal electrode formed thereon; ( II ) a step of metal plating the patterned substrate so as to form the metal electrode only on the region of the substrate which has no photoresist layer formed thereon; and (DU) a step of releasing the residual photoresist layer from the substrate. Compared to conventional methods, the present invention has an advantage in that it can considerably reduce loss of metal ingredients used for forming an electrode, leading to great decrease in production cost thereof; more particularly, the present invention directly forms a desired electrode pattern on a substrate by using a composition for positive type photoresist with excellent thermal resistance and adhesiveness, so that it can considerably reduce loss of metal ingredients used for forming the electrode, eliminate high temperature treatment and decrease deformation of the substrate or the electrode pattern, selectively from the plating and more surely from the metal electrode pattern.

Description

METHOD OF MANUFACTURING METAL ELECTRODE

TECHNICAL FIELD

The present invention relates to a method of manufacturing a metal electrode, and more particularly, to a method of manufacturing a

metal electrode such as silver electrode (hereinafter, referred to as "Ag

electrode") for PDP, which can reduce loss of metal ingredients such as

silver required for plating the metal electrode, thereby considerably

reducing production cost of the metal electrode.

Also, the present invention relates to a method of

manufacturing a metal electrode, and more particularly, to a method of directly forming patterns of the metal electrode, for example, Ag

electrode on an insulating substrate in flat display panel applications,

characterized in that it can reduce loss of metal ingredients of the metal

electrode and not cause deformation of the substrate and/ or the metal

electrode patterns.

BACKGROUND ART

As one of conventional techniques for the formation of a metal electrode, a method for manufacturing Ag electrode of PDP comprises a glass substrate being coated with a resin composition containing silver particles dispersed therein (hereinafter, referred to as "silver paste") by means of screen printing process, then, successively subjected to pre-

baking, exposing, developing, drying and calcination processes to

produce the final Ag electrode.

However, since the above method developed and removed

undesirable portions (that is, any part except electrode formation part)

after application of the silver paste over the glass substrate, it caused

excessive loss of the silver paste and metal ingredients such as silver

required for forming the electrode, causing a problem of increase in

production cost.

Further, since such a method described above formed the

patterns while containing the metal ingredients in a resin composition

and produced the final metal electrode by removing the resin composition with calcination, it generated a lot of pores due to the calcination process. It is known that such pores cause a problem of

affecting the electrode by acting as an obstacle to current flow such that

electrical resistance is increased.

Therefore, it is an abject of the present invention to solve the

above problems and adopt a novel plating method in place of typical methods using metal paste such as Ag paste as described below, so that it can greatly reduce loss of metal ingredients such as silver during the formation of the metal electrode, thereby decreasing the production cost thereof, and is useful for forming the metal electrode with high density. Generally, it is understood that a plating method is to form a

coating on the surface of a metal or non-metal substrate by using

another metal material different from the substrate so as to prevent corrosion of the substrate and/ or improve abrasion resistance, thermal

resistance or polishing properties thereof.

Among those, a common gold-plating method comprises

multiple steps of: washing out impurities from the surface of the

substrate; activating the surface of the substrate with cations; adhering

palladium (Pd) to the surface of the activated substrate; removing Pd and oxidized metal ions adhered to the surface of the substrate; electro-

depositing nickel (Ni) to the surface of the substrate by immersing the

substrate in a solution bath containing Ni ions; and again immersing

the treated substrate in alternative solution bath containing gold (Au) ions to electro -deposit Au to the surface of the substrate. Herein, Au

has reduction potential higher than that of Ni, and Au ions take inner

electrons from Ni. As a result, Ni becomes oxide ion while Au is electro- deposited by the inner electrons from Ni.

Such Au plating method forms a coating of solder paste on a

subject, for example, semiconductor circuit of a substrate to protect the same and the substrate is mostly made of copper (Cu) component with conductive properties.

Next, an illustrative example of electroless Au plating methods for conductive materials will be disclosed as follows.

A substrate normally used in printed circuit board (PCB) has a

construction in that a copper layer is formed to a thickness of 30 to 40 μm on an epoxy substrate, that is, a nonconductor. By the above

plating method, the substrate also has Ni coating to a thickness of 3 to

5 μm and Au coating to a thickness of not more than 0.1 μm, respectively.

After completion of Au plating, the resultant PCB substrate is coated

with the solder paste, loaded with essential parts and dried by passing

the substrate through an oven. The processed PCB substrate prevents surface oxidation thereof and maintains stability of circuit with respect

to external environment.

Such a plating method described above is developed at present as one of circuit fabrication methods. As compared to the silver paste

method requiring a high temperature sintering process, the plating

method includes an etching process instead of the sintering process and can form electrode patterns in a photoresist layer of the substrate without deformation of the substrate and the patterns so that it has an

advantage of preventing undercut. However, it also has a problem in that a part of the photoresist layer cannot tolerate the plating process and is removed from the substrate.

Conductive materials to form an electrode generally include

silver, gold, metal catalyst materials and, especially, the most widely and commonly used material is silver with excellent conductive

properties and less affinity to oxygen.

Conventionally known methods for forming metal electrode

patterns on a substrate include, but are not limited to, silver paste

method, metal deposition method and plating method.

A metal electrode formation method using silver paste normally includes steps of placing a screen mask on an insulating substrate and

applying the silver paste thereon and calcining the silver paste at a temperature of not less than 500 °C , thereby producing the electrode.

Although this method can reduce production processes, it also has

disadvantages such as severe contraction of silver paste pattern caused

by the calcining process at high temperature, higher specific resistance due to additives for facilitating paste formation and adhesion to the substrate, high price of the silver paste and so on.

A metal deposition method includes steps of depositing a metal

seed layer on a substrate so as to increase adhesiveness between the surface of the substrate and the metal electrode, and again depositing a

metal electrode layer over the metal seed layer adhered to the substrate.

Next, the treated substrate is coated with a photoresist layer and undergoes exposing and developing processes to form an electrode pattern on the substrate. The metal electrode layer and the metal seed layer are removed except for the electrode pattern by using an etching solution and the photoresist layer is removed by a releasing process,

thereby forming the electrode. Although the above method has an

advantage of forming microfine patterns with high resolution, it is slow

and shows great loss of raw materials due to an etching process since

deposition of the metal electrode layer and the metal seed layer is repeatedly performed.

The plating method may partially use nickel or chromium based

alloy oxide to form a part of the metal seed layer when the metal seed

layer is deposited on the electrode of the substrate in order to enhance

adhesiveness of the electrode to the substrate. In addition, in order to improve the conductivity of the electrode, a part of the metal seed layer

may be made of conductive metal materials. The substrate is coated

with the photoresist layer and subjected to the exposing and developing processes to form the metal electrode pattern. After the electrode

pattern is formed by an electro-plating process, the photoresist layer is

released and followed by the etching of metal seed layer to finish and complete the substrate.

Electroless plating among the plating methods is a method of

depositing metal moiety on the surface of the substrate by using a reductant to carry out reduction of metal ions into an auto-catalyst without electric power supplied from the outside, the metal ions being contained in a metal salt solution. In comparison with the electro- plating method, the electroless plating method has an advantage in that

it can give a plating layer which is more minute or finer, has uniform

thickness and is applicable to even a substrate based on plastic or

organic materials as well as a conductive material. Moreover, this

method has excellent corrosion resistance and abrasion resistance.

A photoresist or a photoresist film is used in the manufacture of

highly integrated semiconductors such as integrated circuits (IC),

printed circuit boards (PCB), and/ or electronic display devices, such as

cathode ray tubes (CRTs), color LCD displays or organic EL displays.

And, such devices are generally manufactured by using

photolithography and photo-fabrication techniques.

The photoresist film requires a resolution sufficient to form a

pattern with extremely fine lines and small space area of not more than

7 μm ².

The physical properties of the photoresist can be altered, such

as alteration in solubility to certain solvent (that is, increase or decrease

in solubility), coloration, curing and the like, via chemical modification

of the molecular structure of the photoresist resin or the photoresist.

Therefore, it is an object of the present invention to solve the above problems and provide a method of directly forming a metal electrode pattern with improved solidity on an insulating substrate. DISCLOSURE OF INVENTION

(TECHNICAL PROBLEM)

Accordingly, an object of the present invention is to provide a method of manufacturing a metal electrode which can considerably

reduce loss of metal ingredients used for forming the metal electrode

while forming the metal electrode with high density.

In order to achieve the above object, the present invention provides a method of forming a photoresist layer which has excellent

plating resistance under even strong alkali conditions as well as high

film speed, and favorable developing contrast, sensitivity and resolution, on a part of a metal plate before the metal plating process.

Also, the present invention provides a method of forming a

photoresist layer with excellent plating resistance under even strong

alkali condition.

Further, the present invention provides a method of directly

and more securely forming a metal electrode on an insulating substrate without requiring deposition of a plating catalyst. In addition, the

present invention provides a method of manufacturing a metal electrode

which can exclude high temperature treatment and remarkably reduce deformation of the substrate and /or the metal electrode pattern while reducing loss of metal ingredients used for the metal electrode.

Alternatively, the present invention provides a method of forming a photoresist layer with superior thermal resistance,

adhesiveness and plating resistance.

Also, the present invention provides a method of directly

forming a metal electrode on an insulating substrate by the plating

process.

(TECHNICAL MEANS TO SOLVE THE PROBLEM)

In order to achieve the objects described above, there is

provided a method of manufacturing a metal electrode according to the

present invention comprising: (I) a step of forming a photoresist layer

over a whole surface of a substrate by means of coating or laminating

method, then, enabling the whole surface of the substrate with the

photoresist layer to successively undergo pre-baking, exposing, developing and post-baking processes to form a metal electrode pattern,

so that the photoresist layer remains on any region of the substrate

other than a region which has the metal electrode formed thereon; (II) a

step of metal plating the patterned substrate so as to form the metal electrode only on the region of the substrate which has no photoresist

layer formed thereon; and (III) a step of releasing the residual photoresist layer from the substrate.

The above description and the following embodiments are all illustrative of the present invention in order to more specifically describe the present invention as defined by the appended claims.

The objects and other aspects of the present invention will

become apparent from the following examples with reference to the

accompanying drawings. However, the detailed description and

examples are intended to illustrate the invention as preferred

embodiments of the present invention and do not limit the scope of the

present invention. Accordingly, it will be understood to those skilled in the art that various modifications and variations may be made therein

without departing from the scope of the present invention.

Hereinafter, the present invention will be described in detail, with reference to the accompanying drawings.

First, the present inventive method for forming metal electrode

pattern includes steps of: forming a photoresist layer over a whole surface of the substrate by means of coating or lamination method, the photoresist layer comprising an alkali soluble resin, a photosensitive

compound, a thermo-curable cross linking agent and a sensitivity

enhancer; and successively pre-baking, exposing, developing and post- baking the substrate coated with the photoresist layer so as to cause

the photoresist layer to remain on any region of the substrate other than a region which has the photoresist layer formed thereon.

As the method of forming the photoresist layer, there may be used a coating method that coats a substrate with a composition for positive type photoresist comprising an alkali soluble resin, a

photosensitive compound, a thermo-curable cross linking agent, a

sensitivity enhancer and a solvent, or a lamination method that

laminates a positive type photoresist film which includes a supporting

film and a photoresist layer comprising an alkali soluble resin, a

photosensitive compound, a thermo-curable cross linking agent and a

sensitivity enhancer formed on the supporting film, over the whole

surface of the substrate.

The substrate may be a metal plate or an insulating substrate.

The photoresist layer formed over the substrate may further contain a releasing agent.

The composition for positive type photoresist includes, but is

not limited to: a composition comprising 30 to 80 parts by weight of the

photosensitive compound, 3 to 15 parts by weight of the sensitivity enhancer, 10 to 30 parts by weight of the thermo-curable cross linking

agent and 30 to 120 parts by weight of the solvent based on 100 parts

by weight of a thermoplastic resin; a composition comprising 30 to 80

parts by weight of the photosensitive compound, 3 to 15 parts by weight of the sensitivity enhancer, 10 to 30 parts by weight of the thermo- curable cross linking agent and 190 to 250 parts by weight of the solvent based on 100 parts by weight of the alkali soluble resin; or a composition comprising 30 to 80 parts by weight of the photosensitive compound, 3 to 15 parts by weight of the sensitivity enhancer, 10 to 30

parts by weight of the thermo-curable cross linking agent, 1 to 5 parts

by weight of isocyanate compound and 30 to 120 parts by weight of the

solvent based on 100 parts by weight of the alkali soluble resin.

The alkali soluble resin used in the photoresist layer is any of

commercially available alkali soluble resins.

The alkali soluble resin preferably includes, but is not limited to,

thermo-curable novolac resin as a condensation product of phenols and aldehydes and, most preferably ere sol novolac resin.

Novolac resin is obtained by polycondensation of phenols alone

or in combination with aldehydes and an acidic catalyst according to

known reaction mechanisms.

Phenols include, but are not limited to: primary phenols such

as phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-

xylenol, 3,5-xylenol, 2,3,5-trimethylphenol-xylenol, 4-t-5-butylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-methyl-2-t-butylphenol and the like;

and polyhydric phenols such as 2-naphthol, 1 ,3-dihydroxy naphthalene,

1,7-dihydroxy naphthalene, 1,5-dihydroxyl naphthalene, resorcinol, pyrocatechol, hydroquinone, bisphenol A, phloroglucinol, pyrogallol and the like, which may be used alone or in combination. A combination of

m-cresol and p-cresol is particularly preferred.

Suitable aldehydes include, but are not limited to, formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde,

propylaldehyde, phenylacetaldehyde, α or β-phenyl propylaldehyde, o-,

m- or p-hydroxybenzaldehyde, glutaraldehyde, terephthalaldehyde and the like and may be used alone or in combination.

The cresol novolac resin used in the present invention

preferably has a weight average molecular weight (based on GPC) ranging from 2,000 to 30,000.

In addition, the cresol novolac resin for use in the present

invention preferably has a meta/para-cresol content in a mixing ratio

by weight ranging from 4:6 to 6:4, since the resin has varied physical properties such as film speed and film residual rate dependent on the

mixing ratio of the meta/para-cresol content.

If the meta-cresol content among the cresol novolac resin

exceeds the above range, the film speed becomes higher while the film

residual rate is rapidly lowered. On the other hand, the film speed

becomes unfavorably slow when the para-cresol content exceeds the above range.

Although such cresol novolac resin having a meta/para-cresol

content in the mixing ratio by weight ranging from 4:6 to 6:4 can be used alone, more preferably used are resins with different molecular weights in combination. In this case, the cresol novolac resin is preferably a mixture of (i) cresol novolac resin having a weight average molecular weight (based on GPC) ranging from 8,000 to 30,000 and (ii)

cresol novolac resin having a weight average molecular weight (based on

GPC) ranging from 2,000 to 8,000 in a mixing ratio ranging from 7:3 to 9: 1.

The term "weight average molecular weight" used herein refers

to a conversion value of polystyrene equivalent determined by Gel Permeation Chromatography (GPC). If the weight average molecular

weight is less than 2,000, the photoresist resin film exhibits a dramatic

thickness reduction in unexposed regions after development of the film.

On the other hand, when the weight average molecular weight exceeds

30,000, the development speed is lowered thereby reducing sensitivity.

The novolac resin of the present invention can achieve the most

preferable effects when a resin obtained after removing low molecular weight ingredients present in the reaction product has a weight average

molecular weight within the range (of 2,000 to 30,000). In order to

remove the low molecular weight ingredients from the novolac resin, conventional techniques known in the art including fractional precipitation, fractional dissolution, column chromatography and the

like may be conveniently employed. As a result, performance of the photoresist resin film is improved, especially, scumming, thermal resistance, etc.

As the above alkali soluble resin, the novolac resin can be dissolved in an alkaline solution without increase in volume and

provides images exhibiting high resistance to plasma etching when the

resin is used as a mask for the etching.

The photosensitive compound as a constitutional ingredient of

the present inventive composition is a diazide based photosensitive

compound and, in addition, acts as a dissolution inhibitor to reduce

alkali-solubility of the novolac resin. However, this compound is

converted into an alkali- soluble material when light is irradiated

thereon, thereby serving to increase the alkali- solubility of the novolac resin.

The diazide based photosensitive compound may be synthesized

by esterification between a polyhydroxy compound and a

quinonediazide sulfonic compound. The esterification for synthesizing the photosensitive compound comprises: dissolving the polyhydroxy

compound and the quinonediazide sulfonic compound in a solvent such as dioxane, acetone, tetrahydrofuran, methylethylketone, N- methylpyrolidine, chloroform, trichloroe thane, trichloroethylene or

dichloroethane; condensing the prepared solution by adding a basic

catalyst such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, trie thy lamine, N-methyl morpholine, N-methyl piperazine or 4-dimethyl aminopyridine to the solution; and successively washing, purifying and drying the resulting product. Desirable isomers can be selectively esterified and the esterification rate

(average esterification rate) is not specifically limited, but is preferably

in the range of 20 to 100% and more preferably 60 to 90% in terms of the esterification of the diazide sulfonic compound to OH groups of a

polyhydroxy compound. When the esterification rate is too low, pattern

structure and resolution are deteriorated. In contrast, deterioration of

sensitivity occurs if the esterification rate is too high.

The quinonediazide sulfonic compound includes, for example,

o-quinone diazide compounds such as 1,2-benzoquinone diazide-4-

sulfonic acid, 1,2-naphthoquinone diazide-4-sulfonic acid, 1,2- benzoquinone diazide-5-sulfonic acid and 1,2-naphthoquinone diazide-

5-sulfonic acid; and other quinone diazide sulfonic derivatives. The diazide based photosensitive compound is preferably at least one selected from a group consisting of 1,2-benzoquinone diazide-4-sulfonic

chloride, 1,2-naphthoquinone diazide-4-sulfonic chloride and 1,2-

naphthoquinone diazide-5-sulfonic chloride.

The quinonediazide sulfonic compound itself functions as a dissolution inhibitor to decrease the solubility of novolac resin in

alkaline solutions. However, said compound is decomposed to produce alkali soluble resin during an exposing process and, thereby has a characteristic of accelerating the dissolution of novolac resin in an

alkaline solution. As the poly hydroxy compound, preferable examples are:

trihydroxybenzophenones such as 2,3,4-trihydroxy benzophenone,

2,2',3-trihydroxy benzophenone, 2,3,4'-trihydroxy benzophenone; tetrahydroxybenzophenones such as 2,3,4,4-tetrahydroxybenzophenone,

2,2',4,4'-tetreahydroxybenzophenone, 2,3,4,5-

tetrahydroxybenzophenone; pentahydroxy benzophenones such as

2,2',3,4,4'-pentahydroxybenzophenone, 2, 2', 3,4,5- pentahydroxybenzophenone; hexahydroxybenzophenones such as

2,3,3',4,4',5'-hexahydroxybenzophenone, 2,2,3,3' ,4,5'-

hexahydroxybenzophenone; gallic alkylester; oxyflavans, etc.

The diazide based photosensitive compound for use in the

present invention is preferably at least one selected from a group consisting of 2,3,4,4-tetrahydroxybenzophenone-l,2-

naphthoquinonediazide-sulfonate, 2,3,4-trihydroxybenzo phenone- 1 ,2- naphthoquinonediazide-5-sulfonate and (l-[l-(4-

hydroxyphenyl)isopropyl]-4-[ 1 , 1 -bis(4-hydroxyphenyl)ethyl]benzene)-

1,2 -naphthoquinone diazide-5-sulfonate. Also, the diazide based photosensitive compound prepared reacting polyhydroxybenzophenone

and a diazide based compound such as 1,2-naphto quinonediazide, 2- diazo-l-naphthol-5-sulfonic acid may be used.

The diazide based photosensitive compound is concretely described in Chapter 7 of Light Sensitive Systems, Kosar, J.; John Wiley & Sons, New York, 1965.

Such photosensitive compounds (that is, sensitizer) used as a

constitutional ingredient of the resin composition for positive type photoresist according to the present invention is selected from

substituted naphthoquinone diazide based sensitizers generally

employed in positive type photoresist resin compositions, which is

disclosed in, for example, U.S. Patent Nos. 2,797,213; 3,106,465;

3, 148,983; 3,201,329; 3,785,825; and 3,802,885, etc.

The diazide based photosensitive compound described above is

used alone or in combination in an amount of 30 to 80 parts by weight, based on 100 parts by weight of the alkali soluble resin. If less than 30

parts by weight of the diazide based photosensitive compound is used,

the compound does not undergo development in a developing solution

and exhibits drastically reduced residual rate of the photoresist film. In

contrast, if the amount exceeds 80 parts by weight, costs are too high,

thus being economically disadvantageous and, in addition, the

solubility in the solvent becomes lower.

Such a diazide based photosensitive compound is capable of

controlling film speed of the positive type photoresist resin film according to the present invention by procedures including, for example, the control of amount of the photosensitive compound and the control of esterification between the polyhydroxy compound such as 2,3,4- trihydroxybenzophenone and the quinonediazide sulfonic compound

such as 2-diazo-l-naphthol-5-sulfonic acid.

The diazide based photosensitive compound reduces the solubility of alkali soluble resin in an aqueous alkali developing solution

to about 1/ 100th that prior to exposure. However, after the exposure,

the compound is converted into a carboxylic acid soluble in the alkaline solution, thereby exhibiting a solubility increase of about 1000 to 1500 fold, compared to non-exposed positive type photoresist compositions.

The above characteristic is preferably employed in formation of micro-

circuit patterns for devices such as LCDs, organic ELDs and the like. More particularly, a photoresist applied over a silicon wafer or a glass

substrate is subjected to UV irradiation through a semiconductor mask

in a circuit form, and then, is treated using the developing solution,

resulting in a desired circuit pattern remaining on the silicon wafer or

the glass substrate.

The thermo-curable cross linking agent described above comprises, for example, methoxymethylmelamine based resin and is preferably added to the composition in an amount of 10 to 30 parts by

weight based on 100 parts by weight of the alkali soluble resin. If not less than 10 parts by weight of the thermo-curable cross linking agent is used, the present composition shows excellent alkali- resistance and plating resistance. Furthermore, if the amount is not more than 30 parts by weight, it undergoes more convenient developing process.

As the methoxymethylmelamine based resin, more preferable

example is hexamethoxymethylmelamine resin.

Since the photoresist layer contains the thermo-curable cross linking agent as proposed above, it derives cross-linking reaction of the

thermo-curable cross linking agent during formation of the metal

electrode so as to considerably improve alkali-resistance and plating resistance.

The above sensitivity enhancer may be used for improving

sensitivity of the photoresist layer. The sensitivity enhancer comprises a

polyhydroxy compound which contains 2 to 7 phenol based hydroxy

groups and has a weight average molecular weight less than 1,000

relative to polystyrene. Preferred examples are at least one selected from a group consisting of 2,3,4-trihydroxybenzophenone, 2,3,4,4-

tetrahydroxybenzophenone, 1 -[ 1 -(4-hydroxyphenyl)isopropyl]-4-[ 1 , 1 -

bis(4-hydroxyphenyl)ethyl]benzene.

The polyhydroxy compound serving as the sensitivity enhancer is preferably used in an amount of 3 to 15 parts by weight based on 100

parts by weight of the alkali soluble resin. If less than 3 parts by weight of the polyhydroxy compound is used, it exhibits insignificant

photosensitizing effects and unsatisfactory resolution and sensitivity. When the amount exceeds 15 parts by weight, it exhibits high sensitivity but narrows window processing margin.

The solvent contained in the positive type photoresist

composition described above is preferably at least one selected from a

group consisting of ethyl acetate, butyl acetate, ethyleneglycol monoethylether acetate, diethyleneglycol monoethylether acetate,

propyleneglycol monoethylether acetate, acetone, methylethyl ketone,

ethyl alcohol, methyl alcohol, propyl alcohol, isopropyl alcohol, benzene, toluene, cyclopentanone, cyclohexanone, ethyleneglycol, xylene,

ethyleneglycol monoethylether and diethyleneglycol monoethylether.

Amount of the solvent in the present inventive composition preferably ranges from 30 to 120 parts by weight based on 100 parts by

weight of the alkali soluble resin so as to enhance coating effect

achieved by the present invention. If less than 30 parts by weight of the solvent is used, it is unsatisfactory to improve film formation and

lamination properties of the photoresist resin layer. In contrast, when

the amount exceeds 120 parts by weight, adhesiveness of the

photoresist resin layer becomes too high and undesirable.

The above photoresist layer and the composition used for forming the photoresist layer may additionally comprise a releasing agent to improve release properties of a supporting film after lamination, other than the above ingredients. Preferred examples of the releasing agent are silicon resin, fluorine resin, olefin resin, wax, etc. Among these, particularly preferable releasing agent is a fluorine resin with a

viscosity ranging from 1,000 to 10,000cps.

Content of the releasing agent preferably ranges from 0.5 to 4

parts by weight based on 100 parts by weight of the alkali soluble resin.

When the supporting film 10 of the above positive type photoresist film is oriented polypropylene (OPP) film, the OPP film has

superior release properties because of original hydrophobic property in

itself. Therefore, the photoresist layer does not always need to contain

the releasing agent.

However, if the supporting film 10 is polyethylene terephthalate

(PET) film, the film has poor releasing properties caused by original

hydrophilic property in itself. Accordingly, the photoresist layer should contain the releasing agent.

In addition to the above constitutional composition, generally

known components such as additional components such as leveling agents, fillers, pigment, dyes, surfactants and the like and /or additives

for use in conventional photoresist resin compositions may, of course,

be included in the photoresist layer according to the present invention.

As shown in FIG. 1, a photoresist resin film used in the present invention comprises a supporting film 10 and a photoresist layer 20

laminated over the supporting film 10. Occasionally, in order to improve safety of storage and transportation of the positive type photoresist resin film according to the present invention, the film further includes a

protective layer (not shown in drawings) over the photoresist layer 20.

The photoresist layer 20 normally comprises alkali soluble resin, a diazide based photosensitive compound, a thermo-curable cross linking

agent and a sensitivity enhancer.

The supporting film 10 of the invention should have satisfactory

physical properties for the positive type photoresist film. Examples of suitable supporting film materials include, but are not limited to,

polycarbonate film, polyethylene (PE) film, polypropylene (PP) film, OPP film, PET film, polyethylene naphthalate (PEN) film, ethylenevinyl acetate (EVA) film, polyvinyl film, and any suitable polyolefin films,

epoxy film, etc. Particularly preferable polyolefin film is PP film, PE film,

EVA film and so on. Preferable polyvinyl film is polyvinyl chloride (PVC)

film, polyvinyl acetate (PVA) film, polyvinylalcohol (PVOH) film and the

like. Particularly preferable polystyrene film is polystyrene (PS) film,

acrylonitril/butadiene/styrene (ABS) film and so on. In particular, the

supporting film is preferably transparent to allow light to pass through the supporting film and irradiate the photoresist resin layer.

The supporting film 10 may preferably have a thickness ranging from 10 to 50 μm, preferably 15 to 50 μm, and more preferably 15 to 25 μm, in order to function as a framework for supporting shape of the positive type photoresist resin film. A method of forming the positive type photoresist resin layer on

the supporting film comprises coating the supporting film with the

admixture of the present inventive composition and the solvent by way

of generally known coating methods using a roller, roll coater, meyer

rod, gravure, sprayer, etc.; and drying the coated film to volatilize the

solvent. If required, the applied composition may be treated by heating

and curing.

Moreover, the photoresist film used in the present invention

may further comprise a protective layer formed on top of the photoresist

layer. Such a protective layer serves to block air penetration and protect the photoresist resin layer from impurities or contaminants and is preferably a polyethylene film, polyethylene terephthalate film,

polypropylene film, etc. and preferably has a thickness ranging from 15

to 30μm.

The substrate coated with the photoresist layer is successively

subjected to pre-baking, exposing, developing and post-baking

processes to cause the photoresist layer to remain as cross-linked in any region of the substrate other than the region which has the metal electrode thereon.

Herein, the post-baking is carried out at 125 to 150°C for 3 to 20 minutes to progress cross-linking reaction of the thermo-curable cross linking agent in the photoresist layer. If the temperature for post- baking is less than the lower limit, the cross-linking reaction is

insufficient whereby causing a problem such as decrease in plating

properties of the photoresist layer. In contrast, when the temperature exceeds the upper limit, it causes the cross-linking reaction to excessively occur and causes a problem in that it is difficult to release

the photoresist layer from the substrate.

Consequently, the present invention is characterized in that it can remarkably enhance the plating resistance of the photoresist layer

by cross-linking the thermo-curable cross linking agent in the

photoresist layer during the post-baking process.

Next, the substrate partially coated with the photoresist layer described above undergoes a metal plating process to form a metal

electrode only on any region of the substrate which does not have the

photoresist layer formed thereon. Such metal plating process is

conducted under a strong alkali condition of pH 11 to 12 in order to

fulfill fine metal plating on the substrate.

After that, the photoresist layer remaining in the substrate after completion of the above process is removed to produce the metal electrode on the substrate. The produced metal electrode is transferred to a glass substrate by a transcription process in order to fabricate, for

example, Ag electrode for PDP. In this case, the Ag plating process is normally conducted under the strong alkali condition of pH 11 to 12. Meanwhile, if the substrate of the present invention is made of

insulating materials, the present invention may additionally include (a)

a process of depositing a plating catalyst on the insulating substrate

before formation of patterns on the substrate, and (b) a process of etching the plating catalyst deposited on the region with the photoresist

layer released therefrom, using an etching solution after the releasing

process of the photoresist layer.

The insulating substrate includes a glass substrate, a ceramic

substrate, etc. and the plating catalyst includes palladium (Pd),

platinum (Pt), etc.

Examples of the etching solution for the plating catalyst include,

but are not limited to, hydrofluoric acid, hydrochloric acid, nitric acid,

etc.

The metal plating is electroless metal plating, more particularly,

includes electroless gold plating, electroless silver plating, electroless tin

plating, electroless copper plating, etc.

The electroless metal plating is preferably conducted at 80 ^°C for

5 to 20 minutes but can be suitably varied dependent on height of the electrode to be formed.

Furthermore, the present invention may further comprise: (a) a step of etching the substrate with desired patterns; (b) a step of dipping the etched substrate in a coupling agent solution; and (c) a step of dipping the previously dipped substrate in a plating catalyst solution,

between the pattern formation process and the metal electrode formation process.

More particularly, the patterned substrate undergoes a process

of etching a part of the substrate without the photoresist layer (a part to

be hereafter under the electroless metal plating process). The etching

solution includes, for example, hydrofluoric acid, hydrochloric acid,

nitric acid, etc.

After that, the etched substrate is subjected to a process of

applying the coupling agent to the etched part by dipping the substrate

into the coupling agent solution.

Preferred example of the coupling agent is silane based compounds.

Subsequently, the substrate dip treated with the coupling agent

solution is again subjected to a process of applying the plating catalyst to the etched part by dipping the substrate into the plating catalyst

solution.

Contrary to previously known methods, the present invention described above is characterized in that only a part of the substrate to be electroless metal plated is coated with the plating catalyst by means

of dipping process instead of a deposition procedure.

As a result, the present invention can eliminate a relatively complex deposition process of the plating catalyst. In addition, since the

present invention can etch the substrate part to be metal plated before

the electroless metal plating, it leads to extension of surface area for the

substrate part to be plated and greatly improves adhesiveness between

the metal electrode and the substrate.

When the present invention additionally includes the deposition

of the metal catalyst and the etching process of the plating catalyst

using the etching solution, or, multiple dipping processes of the

patterned substrate in the coupling agent solution and the plating

catalyst solution in turn after the etching process, the solvent for

forming the photoresist layer is preferably used in an amount ranging

from 190 to 250 parts by weight based on 100 parts by weight of the alkali soluble resin. If less than 190 parts by weight of the solvent is

used, it is unsatisfactory to improve film formation and lamination

properties of the photoresist resin layer. With the above range, the present invention shows superior coating properties.

In order to improve adhesiveness between the photoresist layer

and the deposited plating catalyst in the positive type photoresist

composition, additives such as, for example, isocyanate based compound or the coupling agent can be used.

It is well known that isocyanate based compounds have high reactivity and, in particular, readily react with some compounds having active hydrogen. Not to be limited to self-reaction thereof, the isocyanate

based compounds also easily react with alcohol, amine, water,

carboxylic acid, epoxide, etc..

Among the coupling agents, especially, a silane based coupling

agent is polymerized by condensation thereof in water at room

temperature. The coupling agent has an organic functional group at one

end while having a methoxy group or ethoxy group at the other end and,

the ethoxy group at the end is hydrolyzed by water to separate ethanol and become Si-OH group. Si-OH group is unstable and converted into Si-O-Si as a siloxane bond so that silane is cross-linked and becomes a

gel state.

Content of the additive preferably ranges from 0.1 to 2 parts by weight based on 100 parts by weight of the alkali soluble resin.

The above described features and other advantages of the

present invention will become more apparent from the following non-

restrictive examples. However, it should be understood that these

examples are intended to illustrate the invention more fully as practical

embodiments and do not limit the scope of the present invention.

(ADVANTAGEOUS EFFECTS)

As described in detail above, the present invention has

advantages in that it can reduce working processes, eliminate deposition of the plating catalyst and considerably reduce loss of metal ingredients used for manufacturing metal electrode, thereby greatly reducing production cost thereof.

Further, the present invention can more precisely manufacture

the metal electrode by using a photoresist layer with high film speed,

and superior developing contrast, sensitivity and resolution.

The present invention can also eliminate high temperature

treatment and reduce deformation of metal electrode pattern and/ or the substrate.

In addition, the present invention can more securely form the metal electrode on a glass substrate. BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and other aspects of the present invention will be apparent from the following preferred embodiments of the invention

with reference to accompanying drawing in which:

Figure 1 is a cross-sectional view illustrating a positive type

photoresist resin film of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Example 1

First, a solution comprising: cresol novolac resin as an alkali soluble resin; 34 parts by weight of l,2-naphthoquinone-2-diazide-5-

sulfonic chloride as a photosensitive compound; 15 parts by weight of hexamethoxymethylmelamine as a thermo-curable cross linking agent;

3.6 parts by weight of 2,3,4-trihydroxybenzophenone as a sensitivity

enhancer; 165 parts by weight of methylethyl ketone and 55 parts by

weight of diethyleneglycol monoethylether acetate as the solvents; and

0.5 parts by weight of fluorine based silicon resin as a releasing agent,

on the base of 100 parts by weight of the above alkali soluble resin, was prepared. The prepared solution was subjected to filtering through a

0.2 μm millipore Teflon™ filter to remove insoluble materials. The

resultant solution was applied to a PET film having a thickness of 19 μm to a thickness of 5 μm to form a positive type photoresist resin film.

After laminating the formed photoresist resin film on a SUS metal plate,

the treated substrate was successively subjected to pre-baking, exposing, developing and post-baking processes to form a photoresist layer on any region of the substrate other than a region which has a

metal electrode formed thereon. Next, Ag electrode was formed on the

region not coated with the photoresist layer by Ag plating process. After separating only the Ag electrode from the SUS metal plate by a releasing

process, the separated Ag electrode was transferred to a glass substrate

by a transcription process to produce the final Ag electrode for PDP. Herein, the post-baking process was performed at 130^°C for 10 minutes while the Ag plating process was conducted under the strong alkali condition of pH 12. Physical properties of the produced positive type photoresist resin layer were evaluated and the results are shown in

Table 2.

Examples 2 to 4 and Comparative Example 1

Each of positive type photoresist resin films and Ag electrodes

was prepared in the same manner as in Example 1 , except that content

of hexamethoxymethylmelamine as the thermo-curable cross linking

agent, temperature and working time of the post-baking process, and

pH condition of the Ag plating process were varied as shown in Table 1.

The results of evaluating physical properties of the produced positive

type photoresist resin layers are shown in Table 2. Table 1

Manufacturing condition

Table 2

Results of physical properties evaluation

* In the comparative example 1, since the positive type

photoresist portion was released during the Ag plating process, it was

nearly impossible to produce the Ag electrode. Physical properties as

shown in Table 2 were evaluated by the following methods.

[Sensitivity evaluation]

After exposing each of the laminated substrates with varied

amount of light, the photoresist layer was developed using 2.38 % by

mass of TMAH solution for 60 seconds and washed for 30 seconds then dried. Exposure amount of the resulting layer was measured using an optical microscope.

[Resolution evaluation]

After lamination of the prepared film onto the substrate at a

lamination speed of 2.0m/min, at a temperature of 110⁰C and under a heating roller pressure of 10 to 90psi, the laminated film was subjected

to UV irradiation using the photomask and removal of PET film as the

supporting film. Subsequently, the treated film was developed using 2.38% TMAH alkali developer, resulting in a micro circuit with

unexposed regions. Resolution of the formed micro circuit was observed using the electron microscope. Example 5

A solution comprising: cresol novolac resin as the alkali soluble resin; 34 parts by weight of l,2-naphthoquinone-2-diazide-5-sulfonic

chloride as the photosensitive compound; 15 parts by weight of

hexamethoxymethylmelamine as the thermo-curable cross linking

agent; 3.6 parts by weight of 2,3,4-trihydroxybenzophenone as the

sensitivity enhancer; and 165 parts by weight of methylethyl ketone and

55 parts by weight of diethyleneglycol monoethylether acetate as the solvents, on the base of 100 parts by weight of the above alkali soluble resin, was prepared. The prepared solution was applied to a SUS metal

plate to a thickness of 3 μm, then successively subjected to pre-baking,

exposing, developing and post-baking processes to form a photoresist

layer on any region of the substrate other than a region which has a

metal electrode formed thereon. Next, Ag electrode was formed on the

region not coated with the photoresist layer by Ag plating process. After

removing the photoresist layer, only the Ag electrode was separated

from the SUS metal plate by the releasing process and transferred to a

glass substrate by the transcription process to produce the final Ag

electrode for PDP. Herein, the post-baking process was performed at 130°C for 10 minutes while the Ag plating process was conducted under

the strong alkali condition of pH 12. Physical properties of the produced positive type photoresist resin layer were evaluated and the results are shown in Table 4. Examples 6 to 8 and Comparative Example 2 Each of positive type photoresist resin layers and Ag electrodes

was prepared in the same manner as in Example 5, except that content

of hexamethoxymethylmelamine as the thermo-curable cross linking agent, temperature and working time of the post-baking process, and

pH condition of the Ag plating process were varied as shown in Table 3.

The results of evaluating physical properties of the produced positive

type photoresist resin layers are shown in Table 4. Table 3

Manufacturing condition

Table 4

Results of physical properties evaluation

* In the comparative example 2, since the positive type photoresist portion was released during the Ag plating process, it was nearly impossible to produce the Ag electrode. Physical properties as

shown in Table 4 were evaluated by the following methods.

[Sensitivity evaluation]

After exposing each of the produced photoresist resin layers which formed a coating to the thickness of 3 μm with varied amount of

light, the photoresist resin layer was developed using 2.38 % by mass of

TMAH solution for 60 seconds and washed for 30 seconds then dried.

Exposure amount of the resulting layer was measured using an optical

microscope.

[Resolution evaluation]

After coating a substrate with the composition (the solution) prepared as described above to the thickness of 3 μm, the coated

substrate was subjected to UV irradiation using a photomask and the formed coating layer was developed using 2.38% TMAH alkali developer,

resulting in a micro circuit with unexposed regions. Resolution of the

produced micro circuit was observed using an electron microscope.

Example 9

chloride as the photosensitive compound; 15 parts by weight of hexamethoxymethylmelamine as the thermo-curable cross linking agent; 3.6 parts by weight of 2,3,4-trihydroxybenzophenone as the sensitivity enhancer; 165 parts by weight of methylethyl ketone and 55 parts by weight of diethyleneglycol monoethylether acetate as the

solvents; and 0.5 parts by weight of fluorine based silicon resin as the

releasing agent, on the basis of 100 parts by weight of the above alkali

soluble resin, was prepared. The prepared solution was subjected to

filtering through a 0.2 μm millipore Teflon™ filter to remove insoluble

materials. The resultant solution was applied to a PET film having a

thickness of 19 μm to a thickness of 5 μm to form a positive type

photoresist film. After laminating the formed positive type photoresist

film on a glass substrate, the treated substrate was successively

subjected to pre-baking, exposing, developing and post-baking processes to form a photoresist layer on any region of the substrate

other than a region which has a metal electrode formed thereon. Next,

the photoresist layer was etched by using hydrofluoric acid, dipped in a silane based compound solution and a Pd solution in turn, and undergoes an electroless Ag plating process to form Ag electrode on a

region of the glass substrate not coated with the photoresist layer. After

removing the photoresist layer from the substrate, the final Ag electrode for PDP was produced. Herein, the post-baking process was performed at 130^°C for 10 minutes while the Ag plating process was conducted

under the strong alkali condition of pH 12. Physical properties of the produced positive type photoresist resin layer were evaluated and the results are shown in Table 6.

Examples 10 to 12 and Comparative Example 3

Each of positive type photoresist resin layers and Ag electrodes was prepared in the same manner as in Example 1 , except that content

of hexamethoxymethylmelamine as the thermo-curable cross linking

agent, temperature and working time of the post-baking process, and

pH condition of the silver plating process were varied as shown in Table

5. The results of evaluating physical properties of the produced positive type photoresist resin films are shown in Table 6.

Table 5

Manufacturing condition

Table 6

Results of physical properties evaluation

* In the comparative example 3, since the positive type photoresist portion was released during the silver plating process, it

was nearly impossible to produce the Ag electrode. Physical properties

as shown in Table 6 were evaluated by the same methods with those for evaluating the physical properties shown in Table 2. Example 13

A solution comprising: cresol novolac resin as the alkali soluble

resin; 34 parts by weight of l,2-naphthoquinone-2-diazide-5-sulfonic chloride as the photosensitive compound; 15 parts by weight of

hexamethoxymethylmelamine as the thermo-curable cross linking agent; 3.6 parts by weight of 2,3,4-trihydroxybenzophenone as the sensitivity enhancer; and 219 parts by weight of methylethyl ketone as

the solvent, on the basis of 100 parts by weight of the above alkali

soluble resin, was prepared. The prepared solution was applied to a glass substrate to a thickness of 3 μm to form a positive type photoresist

layer, and the treated substrate was successively subjected to pre-

baking, exposing, developing and post-baking processes to form a photoresist layer on any region of the substrate other than a region which has a metal electrode formed thereon. Next, the photoresist layer was etched by using hydrofluoric acid, dipped in a silane based compound solution and a Pd solution in turn, and undergoes the electroless Ag plating process to form Ag electrode on a region of the glass substrate not coated with the photoresist layer. After removing the

photoresist layer, the final Ag electrode for PDP was produced. Herein, the post-baking process was performed at 130°C for 10 minutes while

the Ag plating process was conducted under the strong alkali condition

of pH 12. Physical properties of the produced positive type photoresist

resin layer were evaluated and the results are shown in Table 8.

Examples 14 to 16 and Comparative Example 4

Each of positive type photoresist resin layers and Ag electrodes

was prepared in the same manner as in Example 1, except that content of hexamethoxymethylmelamine as the thermo-curable cross linking

agent, temperature and working time of the post-baking process, and

pH condition of the silver plating process were varied as shown in Table

7. The results of evaluating physical properties of the produced positive

type photoresist resin layers are shown in Table 8.

Table 7

Manufacturing condition

Table 8 Results of physical properties evaluation

* In the comparative example 4, since the positive type

photoresist portion was released during the Ag plating process, it was

nearly impossible to produce the Ag electrode. Physical properties as shown in Table 8 were evaluated by the same methods with those for

evaluating the physical properties shown in Table 4.

Example 17

chloride as the photosensitive compound; 15 parts by weight of

hexamethoxymethylmelamine as the thermo-curable cross linking agent; 3.6 parts by weight of 2,3,4-trihydroxybenzophenone as the

sensitivity enhancer; 165 parts by weight of methylethyl ketone and 55

parts by weight of diethyleneglycol monoethylether acetate as the solvents; and 0.5 parts by weight of fluorine based silicon resin as the releasing agent, on the basis of 100 parts by weight of the above alkali

soluble resin, was prepared. The prepared solution was subjected to filtering through a θ.2 p millipore Teflon™ filter to remove insoluble

materials. The resultant solution was applied to a PET film having a thickness of 19 _fan to a thickness of 5 p to form a positive type

photoresist film. After laminating the formed positive type photoresist

film on a glass substrate having Pd deposit formed thereon as a plating

catalyst, the treated substrate was successively subjected to pre-baking, exposing, developing and post-baking processes to form a photoresist

layer on any region of the substrate other than a region which has a

metal electrode formed thereon. Next, Ag electrode was formed on the region not coated with the photoresist layer by the electroless Ag plating

process. After removing the photoresist layer from the substrate by the

releasing process, the final Ag electrode for PDP was formed by etching the plating catalyst deposited on the region from which the photoresist

layer was released. Herein, the post-baking process was performed at 130°C for 10 minutes while the Ag plating process was conducted under

the strong alkali condition of pH 12. Physical properties of the produced positive type photoresist resin layer were evaluated and the results are

shown in Table 10.

Examples 18 to 20 and Comparative Example 5

Each of positive type photoresist resin films and Ag electrodes was prepared in the same manner as in Example 1, except that content of hexamethoxymethylmelamine as the thermo-curable cross linking agent, temperature and working time of the post-baking process, and

pH condition of the Ag plating process were varied as shown in Table 9.

The results of evaluating physical properties of the produced positive

type photoresist resin layers are shown in Table 10.

Table 9

Manufacturing Condition

Table 10

Results of physical properties evaluation

* In the comparative example 5, since the positive type

photoresist portion was released during the silver plating process, it

was nearly impossible to produce the Ag electrode. Physical properties

as shown in Table 10 were evaluated by the same methods with those for evaluating the physical properties shown in Table 2.

Example 21

A solution comprising: cresol novolac resin as the alkali soluble

resin; 34 parts by weight of l,2-naphthoquinone-2-diazide-5-sulfonic

chloride as the photosensitive compound; 15 parts by weight of

hexamethoxymethylmelamine as the thermo-curable cross linking

agent; 3.6 parts by weight of 2,3,4-trihydroxybenzophenone as the sensitivity enhancer; and 219 parts by weight of methylethyl ketone as

the solvent, on the basis of 100 parts by weight of the above alkali

soluble resin, was prepared. The prepared solution was applied to a glass substrate having Pd deposit formed thereon as a plating catalyst,

to a thickness of 3 μm to form a positive type photoresist layer. The

treated substrate was successively subjected to pre-baking, exposing, developing and post-baking processes to form a photoresist layer on any

region of the substrate other than a region which has a metal electrode

formed thereon. Next, Ag electrode was formed on the region not coated with the photoresist layer by the electroless Ag plating process. After removing the photoresist layer from the substrate by the releasing

process, the final Ag electrode for PDP was formed by etching the plating catalyst deposited on the region from which the photoresist layer was released. Herein, the post- baking process was performed at 130^°C

for 10 minutes while the Ag plating process was conducted under the strong alkali condition of pH 12. Physical properties of the produced

positive type photoresist resin layer were evaluated and the results are shown in Table 12.

Examples 22 to 24 and Comparative Example 6

Each of positive type photoresist resin layers and Ag electrodes

was prepared in the same manner as in Example 1 , except that content

pH condition of the silver plating process were varied as shown in Table

11. The results of evaluating physical properties of the produced positive type photoresist resin layers are shown in Table 12.

Table 11

Manufacturing Condition

Table 12

Results of physical properties evaluation

* In the comparative example 6, since the positive type

photoresist portion was released during the Ag plating process, it was

nearly impossible to produce the Ag electrode. Physical properties as

shown in Table 12 were evaluated by the same methods with those for

evaluating the physical properties shown in Table 4.

INDUSTRIAL APPLICABILITY

As described above, the present invention is employed in manufacturing metal electrodes such as, for example, Ag electrode for

PDP.

Claims

WHAT IS CLAIMED IS:

1. A method of manufacturing a metal electrode, comprising: (I) a

step of forming a photoresist layer over a whole surface of a substrate

by means of coating or laminating method, then, enabling the whole

surface of the substrate with the photoresist layer to successively

undergo pre-baking, exposing, developing and post-baking processes to

form a metal electrode pattern, so that the photoresist layer remains on any region of the substrate other than a region which has the metal

electrode formed thereon; (II) a step of metal plating the patterned

substrate so as to form the metal electrode only on the region of the substrate which has no photoresist layer formed thereon; and (III) a

step of releasing the residual photoresist layer from the substrate.

2. The method according to claim 1, wherein the post-baking is carried out at 120 to 150°C for 3 to 20 minutes.

3. The method according to claim 1, wherein the metal plating is performed under a strong alkali condition of pH 11 to 12.

4. The method according to claim 1, wherein a composition for positive type photoresist comprising an alkali soluble resin, a photosensitive compound, a thermo-curable cross linking agent, a sensitivity enhancer and a solvent is applied to the whole surface of a

metal plate.

5. The method according to claim 4, wherein the composition for

positive type photoresist includes 30 to 80 parts by weight of the

agent and 30 to 120 parts by weight of the solvent, based on 100 parts

by weight of the thermoplastic resin.

6. The method according to claim 1, wherein a positive type

photoresist film having a supporting film and a photoresist layer formed on the supporting film, which comprises an alkali soluble resin, a

photosensitive compound, a thermo-curable cross linking agent and a sensitivity enhancer, is laminated on the whole surface of the metal

plate.

7. The method according to claim 6, wherein the photoresist layer includes 30 to 80 parts by weight of a diazide based photosensitive

compound, 10 to 30 parts by weight of the thermo-curable cross linking agent and 3 to 15 parts by weight of the sensitivity enhancer, based on 100 parts by weight of the alkali soluble resin.

8. The method according to claim 4 or 6, wherein the alkali soluble

resin is cresol novolac resin.

9. The method according to claim 8, wherein the cresol novolac

resin has a weight average molecular weight (based on GPC) ranging

from 2,000 to 30,000.

10. The method according to claim 8, wherein the cresol novolac resin has a meta/para-cresol content in a mixing ratio by weight

ranging from 4:6 to 6:4.

11. The method according to claim 8, wherein the cresol novolac

resin is a mixture of (i) cresol novolac resin having a weight average molecular weight (based on GPC) ranging from 8,000 to 30,000 and (ii)

cresol novolac resin having a weight average molecular weight (based on

GPC) ranging from 2,000 to 8,000 in a mixing ratio ranging from 7:3 to 9: 1.

12. The method according to claim 4 or 6, wherein the photosensitive compound is at least one selected from a group consisting of: 2,3,4,4-tetrahydroxybenzophenone-l,2-

naphthoquinonediazide-sulfonate; 2,3,4-trihydroxybenzophenone- 1 ,2-

naphthoquinonediazide-5-sulfonate; and (l-[l-(4-hydroxyphenyl)-

isopropyl]-4-[ 1 , l-bis(4-hydroxyphenyl)ethyl]benzene)- 1 ,2-

naphthoquinonediazide - 5 - sulfonate .

13. The method according to claim 4 or 6, wherein the sensitivity

enhancer is at least one selected from a group consisting of 2,3,4-

trihydroxybenzophenone, 2,3,4,4-tetrahydroxybenzophenone and 1-[1-

(4-hydroxyphenyl)isopropyl]-4-[ 1 , 1 -bis(4-hydroxyphenyl)ethyl]benzene.

14. The method according to claim 4 or 6, wherein the thermo- curable cross linking agent is methoxymethylmelamine based resin.

15. The method according to claim 14, wherein the

methoxymethylmelamine based resin is hexamethoxymethylmelamine

resin.

16. The method according to claim 4, wherein the composition for positive type photoresist includes 30 to 80 parts by weight of the photosensitive composition, 3 to 15 parts by weight of the sensitivity enhancer, 10 to 30 parts by weight of the thermo-curable cross linking agent and 190 to 250 parts by weight of the solvent, based on 100 parts

by weight of the alkali soluble resin.

17. The method according to claim 4 or 16, wherein the solvent is

at least one selected from a group consisting of ethyl acetate, butyl

acetate, ethyleneglycol monoethylether acetate, diethyleneglycol

monoethylether acetate, propyleneglycol monoethylether acetate,

acetone, methylethyl ketone, ethyl alcohol, methyl alcohol, propyl alcohol, isopropyl alcohol, benzene, toluene, cyclopentanone, cyclohexanone, ethyleneglycol, xylene, ethyleneglycol monoethylether

and diethyleneglycol monoethylether.

18. The method according to claim 1, wherein a composition for

positive type photoresist comprising an alkali soluble resin, a

photosensitive compound, a thermo-curable cross linking agent, a sensitivity enhancer, an isocyanate compound and a solvent is applied

to the whole surface of the substrate.

19. The method according to claim 18, wherein the composition for positive type photoresist includes 30 to 80 parts by weight of the

photosensitive compound, 3 to 15 parts by weight of the sensitivity enhancer, 10 to 30 parts by weight of the thermo-curable cross linking agent, 1 to 5 parts by weight of the an isocyanate compound and 30 to

120 parts by weight of the solvent, based on 100 parts by weight of the alkali soluble resin.

20. The method according to claim 1, wherein a positive type photoresist film having a supporting film and a photoresist layer formed

on the supporting film, which comprises an alkali soluble resin, a

photosensitive compound, a thermo-curable cross linking agent, an

isocyanate compound and a sensitivity enhancer, is laminated on the whole surface of the substrate.

21. The method according to claim 20, wherein the photoresist

layer includes 30 to 80 parts by weight of a diazide based photosensitive

compound, 10 to 30 parts by weight of the thermo-curable cross linking

agent, 1 to 5 parts by weight of the an isocyanate compound and 3 to 15 parts by weight of the sensitivity enhancer, based on 100 parts by weight of the alkali soluble resin.

22. The method according to claim 18, wherein the solvent is at least one selected from a group consisting of ethyl acetate, butyl acetate, ethyleneglycol monoethylether acetate, diethyleneglycol monoethylether

acetate and propyleneglycol monoethylether acetate.

23. The method according to claim 1, further comprising: (a) a

step of etching the substrate formed patterns; (b) a step of dipping the

etched substrate in a coupling agent solution; and (c) a step of dipping

the previously dipped substrate in a plating catalyst solution, between

the step of forming the pattern on the substrate and the step of forming the metal electrode.

24. The method according to claim 1, wherein it additionally

includes: (a) a process of depositing a plating catalyst on the insulating

substrate before formation of patterns on the substrate, and (b) a

process of etching the plating catalyst deposited on the region with the

photoresist layer released therefrom, by using an etching solution after the releasing process of the photoresist layer.

25. The method according to claim 24, wherein the etching solution for the plating catalyst is one selected from a group consisting

of hydrofluoric acid, hydrochloric acid and nitric acid.

26. The method according to claim 1, wherein the metal plating is electroless metal plating.

27. The method according to claim 26, wherein the electroless

metal plating is one selected from a group consisting of electroless gold

plating, electroless silver plating, electroless tin plating and electroless

copper plating.

28. The method according to claim 1, wherein the substrate is one

selected from a metal plate and an insulating substrate.

29. The method according to claim 28, wherein the insulating

substrate is a glass plate.