KR102814475B1 - Solder resist composition - Google Patents

Abstract

The present invention relates to a solder resist composition having excellent developability, film pressability, sensitivity and electrical insulation properties.

Description

SOLDER RESIST COMPOSITION

The present invention relates to a solder resist composition having excellent developability, film pressability, sensitivity and electrical insulation properties.

Since solder resist compositions can form various types of micro-patterns by applying the principle of photolithography, they are utilized in various forms to form micro-circuit patterns on electronic devices or printed circuit boards. For example, solder resist compositions are used in the manufacture of printed wiring boards, the manufacture of liquid crystal displays, or printing plates.

Solder resist is used as a protective material for printed circuit boards to prevent solder from attaching to unnecessary areas during solder formation, prevent solder bridges from forming, and maintain electrical insulation of conductive parts. With the enlargement and thinning of substrates, various studies are being conducted on solder resists that can form a thin coating layer over a wide area and have high precision. For example, Patent No. 10-1063048 discloses an alkaline developing type solder resist comprising a carboxyl group-containing photosensitive resin, an oxime ester photopolymerization initiator, a compound having an ethylenically unsaturated group, and a thermosetting component.

Conventionally, acid-modified epoxy acrylate resins have been generally used in solder resist compositions. Such acid-modified epoxy acrylate resins are obtained by reacting an epoxy group of an epoxy resin with acrylic acid or methacrylic acid to generate an intermediate compound having a secondary hydroxyl group, and then reacting a polybasic acid anhydride with the secondary hydroxyl group of the intermediate compound. However, the acid-modified epoxy acrylate resins obtained in this manner have a high density of photosensitive groups, so that they crack due to shrinkage after curing or have poor adhesion. In addition, even after the raw epoxy resin containing a chlorine component was modified into epoxy acrylate, the chlorine component did not disappear. Such chlorine component accelerated the migration of copper (Cu) ions in a printed circuit board, and when a current was applied, copper ions were reduced to copper, causing a circuit short-circuit defect between wirings.

In order to solve these problems, attempts have been made to reduce the chlorine content in the composition by mixing in a carboxyl group-containing resin that does not contain chlorine ions, but these resins have problems such as low sensitivity, remaining sticky when pre-dried, causing press marks on the film when exposed to contact light, or contaminating the negative film.

Accordingly, there is a need for the development of a solder resist composition having excellent developability, film pressability, and sensitivity without problems caused by chlorine components.

The present invention provides a solder resist composition having excellent developability, film pressability, sensitivity and electrical insulation properties.

The present invention provides a solder resist composition comprising a photosensitive resin, an epoxy resin, an acrylic, a photoinitiator, and a filler, wherein the photosensitive resin comprises an epoxy resin-based acid-modified epoxy acrylate resin, wherein the epoxy resin-based acid-modified epoxy acrylate resin is prepared by reacting an epoxy resin with a carboxyl compound containing a hydroxyl group and performing an addition reaction with an acid anhydride to an intermediate compound, wherein the molar ratio of the primary hydroxyl group and the secondary hydroxyl group of the intermediate compound is 2:10 to 6:10.

The present invention provides a solder resist composition having excellent developability, film pressability, sensitivity and electrical insulation. The solder resist composition of the present invention is prepared by reacting an epoxy resin and a carboxyl compound containing a hydroxyl group to produce an intermediate compound by addition reacting an acid anhydride, and by using an acid-modified epoxy acrylate resin in which the molar ratio of the primary hydroxyl group and the secondary hydroxyl group of the intermediate compound is controlled as a photosensitive resin, thereby realizing excellent developability, film pressability, sensitivity and electrical insulation.

Hereinafter, the present invention will be described in detail. However, it is not limited to the following contents, and each component may be variously modified or selectively mixed as needed. Therefore, it should be understood that all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention are included.

The functional group such as "acid value" used in this specification is measured by a conventional method known in the art, and can be measured, for example, by a titration method. The "weight average molecular weight" is measured by a conventional method known in the art, and can be measured, for example, by a gel permeation chromatography (GPC) method. The "softening point" is measured by a conventional method known in the art, and can be measured, for example, by a dropping point meter (Dropping Point system calorimetry DP70) of Mettler Toledo. The "average particle diameter ( _D50 )" is measured by a conventional method known in the art, and can be measured, for example, by a laser particle size analyzer.

A solder resist composition according to the present invention includes a photosensitive resin, an epoxy resin, an acrylic, a photoinitiator, and a filler, wherein the photosensitive resin includes an epoxy resin-based acid-modified epoxy acrylate resin, wherein the epoxy resin-based acid-modified epoxy acrylate resin is prepared by reacting an epoxy resin with a hydroxyl group-containing carboxyl compound to produce an intermediate compound through addition reaction with an acid anhydride, and a molar ratio of a primary hydroxyl group and a secondary hydroxyl group of the intermediate compound is 2:10 to 6:10. The solder resist composition according to the present invention may further include additives commonly used in the relevant technical field, such as a hydrophobic oligomer, a solvent, a pigment, a catalyst, an ion catcher, and a dispersant, as needed, without impairing the inherent physical properties and characteristics.

Conventionally, acid-modified epoxy acrylate resins used as photosensitive resins in solder resist compositions have a high density of photosensitive groups, which causes cracking due to shrinkage after curing or insufficient adhesion. In addition, even after the raw epoxy resin containing a chlorine component is modified into epoxy acrylate, the chlorine component does not disappear, which accelerates the migration of copper (Cu) ions on the printed circuit board and causes a circuit short-circuit defect between wirings due to the reduction of copper ions to copper when current is applied. Meanwhile, there have been attempts to lower the chlorine content in the composition by mixing in a carboxyl group-containing resin that does not contain chlorine ions, but such resins have problems such as low sensitivity, remaining sticky during preliminary drying, causing indentations on the coating film during contact exposure, or contaminating the negative film. The solder resist composition according to the present invention uses an epoxy resin-based acid-modified epoxy acrylate resin prepared by subjecting an intermediate compound having a molar ratio of primary hydroxyl groups and secondary hydroxyl groups of 2:10 to 6:10 as a photosensitive resin to an acid anhydride addition reaction, thereby exhibiting sufficient alkaline developability even with a small amount of acid addition, and providing excellent film pressing properties, sensitivity, and film strength.

Photosensitive resin

The solder resist composition of the present invention includes a photosensitive resin. The photosensitive resin serves to impart photocurability and developability to the solder resist composition.

1st photosensitive resin

The above photosensitive resin may include an epoxy resin-based acid-modified epoxy acrylate resin. The above acid-modified epoxy acrylate resin is prepared by adding an acid anhydride to an intermediate compound prepared by reacting an epoxy resin with a carboxyl compound containing a hydroxyl group.

For example, the intermediate compound can be prepared by reacting an epoxy resin, a carboxyl compound containing a primary hydroxyl group, and a carboxyl compound containing an unsaturated group.

The epoxy resin may be a novolac epoxy resin, and may include at least one selected from the group consisting of, for example, a phenol novolac epoxy resin and a cresol novolac epoxy resin.

The carboxyl compound containing the above primary hydroxyl group may include, for example, dimethylolpropionic acid, dimethylolbutanoic acid, glycolic acid, and 2,3-dihydroxy-3-methylpentanoic acid.

The carboxyl compound containing the above unsaturated group may include, for example, (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, vinylacetic acid, crotonic acid, and compounds obtained by adding an acid anhydride to 2-hydroxyethyl acrylate.

For example, the intermediate compound can be prepared by reacting 0.05 to 0.35 equivalents, for example, 0.1 to 0.3 equivalents, of a carboxyl compound including a primary hydroxyl group and 0.65 to 0.95 equivalents, for example, 0.7 to 0.9 equivalents, of a carboxyl compound including an unsaturated group, with respect to 1 equivalent of an epoxy group of an epoxy resin. If the equivalent of at least one of the carboxyl compound including a primary hydroxyl group and the carboxyl compound including an unsaturated group is less than the above-mentioned range, the content of the polybasic acid anhydride added to the secondary hydroxyl group may increase, which may lower the developability, and if it exceeds the above-mentioned range, the amount of unsaturated group introduced may decrease, which may lower the curing speed and the coating strength.

The molar ratio of the primary hydroxyl group and the secondary hydroxyl group of the intermediate compound manufactured by the above reaction may be 2:10 to 6:10, for example, 3:10 to 5:10. Here, the primary hydroxyl group is a hydroxyl group having one alkyl group attached to an adjacent carbon atom, and the secondary hydroxyl group is a hydroxyl group having two alkyl groups attached to adjacent carbon atom. If the ratio of the primary hydroxyl group to the secondary hydroxyl group is less than the above-mentioned range, the stability at high temperature and high humidity may deteriorate, and if it exceeds the above-mentioned range, the sensitivity may be low and the film may be damaged by the developer.

The above epoxy resin-based acid-modified epoxy acrylate resin can be produced by addition reaction of an acid anhydride to the above intermediate compound. When reacting an acid anhydride with a hydroxyl group of the intermediate compound, the acid anhydride preferentially reacts with a primary hydroxyl group rather than a secondary hydroxyl group. In this way, the carboxylic acid produced by reacting an acid anhydride with a primary hydroxyl group of the intermediate compound has better developability for an alkaline developer than the carboxylic acid produced by reacting an acid anhydride with a secondary hydroxyl group.

Therefore, when using the acid-modified epoxy acrylate resin according to the present invention, sufficient alkaline developability can be achieved even with a small amount of acid added, and since the amount of hydroxyl groups is large, the strength of the coating film is increased by stronger hydrogen bonding, so that a solder resist composition with excellent coating film pressability and sensitivity can be provided.

The above acid anhydrides may include polybasic acid anhydrides such as, for example, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride.

For example, the epoxy resin-based acid-modified epoxy acrylate resin can be prepared by adding 0.2 to 0.8 equivalents of an acid anhydride to the intermediate compound solution. If the equivalent of the acid anhydride is less than the above-mentioned range, the developability may be deteriorated, and if it exceeds the above-mentioned range, the film strength, electrical insulation, and adhesion may be deteriorated.

As another example, the epoxy resin-based acid-modified epoxy acrylate resin may be reacted by further adding 0.01 to 0.05 equivalents of an acid anhydride, for example, 0.02 to 0.04 equivalents, in the step of preparing the intermediate compound solution.

The above epoxy resin-based acid-modified epoxy acrylate resin may have a solid acid value of 50 to 100 mgKOH/g, for example, 54 to 57 mgKOH/g. When the solid acid value of the epoxy resin-based acid-modified epoxy acrylate resin is below the above-mentioned range, developability may be deteriorated, and when it exceeds the above-mentioned range, film strength, electrical insulation, and adhesion may be deteriorated.

The above epoxy resin-based acid-modified epoxy acrylate resin may have an acrylic equivalent of 200 to 600 g/eq, for example, 370 to 550 g/eq. If the acrylic equivalent is less than the above-mentioned range, the deep curing property may be reduced and the flexibility of the coating film may be reduced and easily broken, and if it exceeds the above-mentioned range, the strength of the coating film may be reduced and the scratch resistance may be insufficient.

Second photosensitive resin

The above photosensitive resin may further include an acid-modified acrylate resin based on an alkylene oxide addition novolac resin. The above alkylene oxide addition novolac resin-based acid-modified acrylate resin is prepared by reacting an alkylene oxide addition novolac resin with a carboxyl compound containing an unsaturated group, and then adding an acid anhydride to an intermediate compound.

For example, the alkylene oxide may be ethylene oxide or propylene oxide. The novolac resin may include at least one selected from the group consisting of a phenol novolac resin and a cresol novolac resin. The carboxyl compound including an unsaturated group may include, for example, (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, vinylacetic acid, crotonic acid, and a compound obtained by adding an acid anhydride to 2-hydroxyethyl acrylate. The acid anhydride may include, for example, a polybasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride.

For example, the acid-modified acrylate resin based on the alkylene oxide addition novolac resin may be manufactured through a step of reacting 0.3 to 0.6 equivalents of a carboxyl compound including an unsaturated group with respect to 1 equivalent of the alkylene oxide addition novolac resin to prepare an intermediate compound solution; and a step of additionally reacting 0.5 to 1 equivalent of an acid anhydride with respect to 1 equivalent of a hydroxyl group of the intermediate compound to prepare an acid-modified acrylate resin.

The above-described alkylene oxide addition novolac resin-based acid-modified acrylate resin may contain less than 30 ppm of chlorine ions, or may be an acid-modified acrylate resin that does not contain chlorine ions. When the acid-modified acrylate resin containing little or no chlorine ions is additionally included, the concentration of chlorine in the solder resist composition is lowered, thereby preventing the acceleration of migration of copper ions of the printed circuit board due to the chlorine component, and suppressing the occurrence of circuit short-circuit defects between wirings due to the reduction of copper ions to copper by current application.

The acid-modified acrylate resin based on the above alkylene oxide addition novolac resin may have a solid acid value of 50 to 100 mgKOH/g, for example, 70 to 90 mgKOH/g. When the solid acid value of the acid-modified acrylate resin is below the above-mentioned range, the developability may be deteriorated, and when it exceeds the above-mentioned range, the film strength, electrical insulation, and adhesion may be deteriorated.

The above photosensitive resin may include the first photosensitive resin and the second photosensitive resin.

The mixing ratio of the first photosensitive resin and the second photosensitive resin may be a weight ratio of 40:60 to 90:10, for example, 50:50 to 60:40. When the mixing ratio of the first photosensitive resin and the second photosensitive resin is within the above-mentioned range, excellent electrical insulation, film pressing properties, developability, and sensitivity can be provided.

The solder resist composition of the present invention may contain 30 to 50 wt%, for example 35 to 45 wt%, of the photosensitive resin based on the total weight of the solder resist composition. If the content of the photosensitive resin is less than the above-mentioned range, physical properties such as heat resistance and solvent resistance may deteriorate, and if it exceeds the above-mentioned range, storage stability may deteriorate and flowability may deteriorate, thereby deteriorating workability.

Epoxy resin

The solder resist composition according to the present invention comprises an epoxy resin. The epoxy resin serves to impart thermosetting properties to the solder resist composition.

As the above epoxy resin, polyglycidyl ethers of polyhydric phenols and derivatives thereof can be used. For example, polyglycidyl ethers of polyhydric phenols, such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac epoxy resin, phenol-novolac epoxy resin, cresol-novolac epoxy resin, N-glycidyl epoxy resin, bisphenol A type novolac epoxy resin, chelate epoxy resin, glyoxane epoxy resin, amino group-containing epoxy resin, rubber-modified epoxy resin, dicyclopentadiene phenolic epoxy resin, silicon-modified epoxy resin, ε-caprolactone-modified epoxy resin, bisphenol S epoxy resin, diglycidyl phthalate resin, heterocyclic epoxy resin, and biphenyl epoxy resin can be used.

The above epoxy resin may be used by mixing two or more types of epoxy resins. For example, the epoxy resin may include a bisphenol-type epoxy resin and a biphenyl epoxy resin. As another example, the epoxy resin may include a bisphenol A-type epoxy resin and a biphenyl epoxy resin. When the above two types of epoxy resins are mixed, excellent adhesion and chemical resistance effects can be obtained from the bisphenol-type epoxy resin, while the effects of supplementing heat resistance and heat stability under heat-drying conditions can be obtained from the biphenyl epoxy resin.

The bisphenol A type epoxy resin may be one having an epoxy equivalent of 200 to 600 g/eq, for example, 400 to 550 g/eq, a softening point of 50 to 100° C., and a weight average molecular weight of 1,000 to 5,000 g/mol, for example, 1,000 to 3,000 g/mol. When the properties of the bisphenol A type epoxy resin satisfy the above-mentioned range, excellent adhesion and chemical resistance can be exhibited.

For example, the bisphenol-type epoxy resin may be a bisphenol A-type epoxy resin represented by the following chemical formula 1.

[Chemical Formula 1]

The biphenyl epoxy resin may be one having an epoxy equivalent of 100 to 1,000 g/eq, for example, 100 to 300 g/eq, a softening point of 50 to 150°C, and a weight average molecular weight of 300 to 20,000 g/mol, for example, 300 to 1,000 g/mol. When the properties of the biphenyl epoxy resin satisfy the above-mentioned range, excellent heat resistance and heat stability can be exhibited.

For example, the biphenyl epoxy resin may be represented by the following chemical formula 2.

[Chemical formula 2]

In the above formula, each R is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

The above epoxy resin may further include an aliphatic epoxy resin, a fatty acid epoxy resin derived from a natural product, a polybutadiene epoxy resin, a cycloaliphatic epoxy resin, etc. These may be used alone or in a mixture of two or more types.

The solder resist composition of the present invention may contain 1 to 30 wt%, for example, 5 to 15 wt%, of the epoxy resin, based on the total weight of the solder resist composition. For example, the solder resist composition may contain 1 to 15 wt%, for example, 3 to 10 wt%, of the bisphenol A type epoxy resin, and 1 to 15 wt%, for example, 1 to 5 wt%, of the biphenyl epoxy resin, based on the total weight of the solder resist composition. When the content of each epoxy resin is less than the above-mentioned range, the curing promotion effect may be insufficient, and when it exceeds the above-mentioned range, the coating appearance may become poor or the strength of the coating film may become weak.

acryl

The solder resist composition according to the present invention comprises acrylic. The acrylic may include acrylic monomer and acrylic oligomer, and the acrylic serves to impart photocurability.

The above acrylic may be a monofunctional acrylic monomer, a polyfunctional acrylic monomer, a urethane acrylate, a polyester acrylate or a mixture thereof.

Non-limiting examples of the above monofunctional acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isoamyl (meth)acrylate, isomyristyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate, isostearyl (meth)acrylate, long-chain alkyl (meth)acrylate, n-butoxyethyl (meth)acrylate, butoxydiethylene glycol (meth)acrylate, cyclohexyl (meth)acrylate, Tetrahydrofurfuryl (meth)acrylate, butoxyethyl (meth)acrylate, 2-ethylhexyl-diglycol (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, benzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-(2-vinyloxyethoxy)ethyl (meth)acrylate, glycidyl (meth)acrylate, methoxyethylene glycol modified (meth)acrylate, ethoxyethylene glycol modified (meth)acrylate, propoxyethylene glycol modified (meth)acrylate, There are methoxypropylene glycol modified (meth)acrylate, ethoxypropylene glycol modified (meth)acrylate, propoxypropylene glycol modified (meth)acrylate, tetrahydrofuryl (meth)acrylate, acryloylmorpholine, acryloxy ethyl phthalate, etc., and these can be used alone or in combination of two or more.

Non-limiting examples of the above multifunctional acrylic monomers include trifunctional (meth)acrylate monomers such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, etc.; tetrafunctional (meth)acrylate monomers such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, etc.; dipentaerythritol poly(meth)acrylates such as dipentaerythritol hexa(meth)acrylate, etc., which may be used alone or in a mixture of two or more.

The solder resist composition of the present invention may contain 1 to 10 wt%, for example 2 to 6 wt%, of the acrylic based on the total weight of the solder resist composition. If the content of the acrylic is less than the above-mentioned range, photocurability may be insufficient, making it difficult to form a pattern by alkaline development after light irradiation, and if it exceeds the above-mentioned range, the touch-drying property of the coating film may deteriorate, or the solubility of the solder resist composition in an alkaline aqueous solution, which is a developer, may deteriorate, making the coating film vulnerable.

Photon initiator

The solder resist composition of the present invention contains a photoinitiator. The photoinitiator improves the curability of the solder resist composition, thereby improving not only surface but also deep curability, thereby improving the fine pattern formation ability.

The above photoinitiator may include a short wavelength photoinitiator having an effective absorption wavelength of 250 to 315 nm.

The photoinitiator may include a benzophenone-based compound, a benzoin alkyl ether-based compound, an acetophenone-based compound, a thioxanthone-based compound, an alkylanthraquinone-based compound, an acylphosphine oxide-based compound, and the like. For example, the photoinitiator may be an α-amino acetophenone-based compound, for example, 2-benzyl-2-dimethylamino-1-(4-morpholino-phenyl)-1-butanone, 2-methyl-1-[(4-methylthio)phenyl]-2-(4-morpholino-phenyl)-1-propanol, 2-(4-methylbenzyl)-2-(dimethylamino)-1-(4-morpholinophenyl)butan-1-one, and the like, and these may be used alone or in combination of two or more.

As another example, the photoinitiator may include an oxime ester photoinitiator that has excellent photosensitivity and can be activated by a small amount of UV. For example, a carbazole oxime ester photoinitiator, a fluorene photoinitiator, etc. may be used. The oxime ester photoinitiator may be used alone or in combination with the other photoinitiators described above.

The solder resist composition of the present invention may contain 1 to 15 wt%, for example 1 to 5 wt%, of the photoinitiator based on the total weight of the solder resist composition. If the content of the photoinitiator is less than the above-mentioned range, the radical initiation reaction does not occur smoothly upon exposure to light, making it difficult to proceed with curing, which may inhibit film formation and pattern formation, and if it exceeds the above-mentioned range, the reaction speed between the radical of the photoinitiator and the double bond may be too fast, making it difficult for the curing reaction to proceed uniformly on the surface or deep, or making it difficult to form a high molecular weight, which may make it difficult to form a film.

Filler

The solder resist composition according to the present invention includes a filler. The filler is a filler for improving physical properties such as strength, and is not particularly limited as long as it is used in the relevant technical field. For example, inorganic fillers such as barium sulfate, talc, silica, aluminum oxide, aluminum hydroxide, etc.; organic fillers such as silicone, urethane, polymethyl methacrylate, butadiene, etc.; or mixtures thereof can be used.

The above filler may include a filler having an average particle diameter (D ₅₀ ) of 5 ㎛ or less, for example, 0.1 to 5 ㎛. If the average particle diameter (D ₅₀ ) exceeds the above-mentioned range, unevenness may occur due to the filler protruding on the side portion of the solder resist pattern line formed after exposure and pattern development, and if it is less than the above-mentioned range, dispersibility may be poor and the coating property may be deteriorated due to viscosity.

The solder resist composition of the present invention can use two types of fillers having different average particle diameters (D ₅₀ ). In this case, heat resistance, hardness, and film adhesion can be improved while obtaining excellent resolution.

For example, the filler may include barium sulfate. The filler may have an average particle diameter (D ₅₀ ) of less than 1 μm, for example, 0.01 to 0.9 μm.

The solder resist composition of the present invention may contain 20 to 40 wt%, for example 25 to 35 wt%, of the filler based on the total weight of the solder resist composition. If the content of the filler is less than the above-mentioned range, the strength and physical properties may be deteriorated, and if it exceeds the above-mentioned range, the resolution may be deteriorated.

hydrophobic oligomer

The solder resist composition according to the present invention may further include a hydrophobic oligomer. The hydrophobic oligomer serves to impart photocurability.

Non-limiting examples of the above hydrophobic oligomers include epoxidized polybutadiene resins, epoxidized acrylate resins, aliphatic urethane acrylates, aromatic urethane acrylates, polyester acrylates, etc., which may be used alone or in combination of two or more.

The epoxidized polybutadiene resin may have an epoxy equivalent of 50 to 500 g/eq, for example, 100 to 300 g/eq. If the epoxy equivalent of the epoxidized polybutadiene resin is less than the above-mentioned range, environmental reliability may be poor and the coating film may be damaged after development, and if it exceeds the above-mentioned range, the difference in curing of the coating film between the surface and the deep portion may be large, resulting in undercut defects.

The solder resist composition of the present invention may contain 1 to 10 wt%, for example 3 to 7 wt%, of the hydrophobic oligomer based on the total weight of the solder resist composition. If the content of the hydrophobic oligomer is less than the above-mentioned range, the developability may be poor and the coating film may be damaged after development, and if it exceeds the above-mentioned range, the difference in curing of the coating film between the surface and the deep portion may be large, resulting in undercut defects and reduced resolution.

Additives

The solder resist composition according to the present invention may further contain a solvent, pigment, and other additives as needed.

The solvent is for viscosity adjustment and is not particularly limited as long as it is used in the relevant technical field. For example, dipropylene glycol monoethyl ether, naphtha, etc. can be used as the solvent.

Pigments are used to impart a coloring effect, and are not particularly limited as long as they are used in the relevant technical field. For example, azo pigments, phthalocyanine pigments, etc. can be used as the pigments.

In addition, additives commonly used in the relevant technical field, such as catalysts, ion catchers, and dispersants, can be used. The catalyst is intended to promote the thermosetting reaction, and is not particularly limited as long as it is used in the relevant technical field. For example, melamine, etc. can be used as the catalyst. The ion catcher is intended to remove eluted ions, and is not particularly limited as long as it is used in the relevant technical field. For example, Al, Mg, Zr series inorganic materials, etc. can be used. The dispersant is intended to help disperse the filler, and is not particularly limited as long as it is used in the relevant technical field. For example, a low-molecular-weight dispersant having a number average molecular weight of 1,000 g/mol or less can be used as the dispersant.

The above additives may be added within a content range that does not impair the physical properties of the solder resist composition of the present invention, and for example, may be included in an amount of 0.01 to 10 wt% based on the total weight of the solder resist composition, but is not limited thereto.

The present invention will be described more specifically through the following examples. However, the following examples are only intended to help understand the present invention, and the scope of the present invention is not limited to the examples in any way.

[Synthesis Example 1-8]

Synthesis Example 1: Photosensitive Resin 1

In a reactor equipped with a stirrer, a thermometer, and an air intake tube, 396 g of cresol novolac epoxy resin (YDCN-500-90P, Kukdo Chemical) having an epoxy equivalent of 215 g/eq, 119 g of acrylic acid, 25 g of dimethylolpropionic acid, 2 g of triphenylphosphine, and 240 g of carbitol acetate were charged, air was blown in, and an epoxy addition reaction was performed at 100 to 110°C for 12 hours while stirring. After confirming that the acid value decreased to 2 mgKOH/g or less, the mixture was cooled to prepare an intermediate compound solution having a molar ratio of the first hydroxyl group: the second hydroxyl group of 2:10.

Afterwards, 98 g of tetrahydrophthalic anhydride and 120 g of solvent naphtha were added to the intermediate compound solution, and air was blown in to conduct an acid anhydride addition reaction at 95 to 100°C for 8 hours. After confirming that the absorption spectrum of the acid anhydride disappeared in IR, the mixture was cooled to produce photosensitive resin 1.

The manufactured photosensitive resin 1 was confirmed to have an acrylic equivalent of 385 g/eq, a solid acid value of 56.6 mgKOH/g, and a solid content of 64%.

Synthesis Example 2: Photosensitive Resin 2

In a reactor equipped with a stirrer, a thermometer, and an air intake tube, 393 g of cresol novolac epoxy resin (YDCN-500-90P, Kukdo Chemical) having an epoxy equivalent of 215 g/eq, 115 g of acrylic acid, 25 g of dimethylolpropionic acid, 8 g of tetrahydrophthalic anhydride, 2 g of triphenylphosphine, and 240 g of carbitol acetate were charged, air was blown in, and an epoxy addition reaction was performed at 100 to 110°C for 12 hours while stirring. After confirming that the acid value decreased to 2 mgKOH/g or less, cooling was performed to prepare an intermediate compound solution having a molar ratio of the first hydroxyl group: the second hydroxyl group of 2:10.

Afterwards, 97 g of tetrahydrophthalic anhydride and 120 g of solvent naphtha were added to the intermediate compound solution, air was blown in, and an acid anhydride addition reaction was performed at 95 to 100°C for 8 hours. After confirming that the absorption spectrum of the acid anhydride disappeared in IR, the mixture was cooled to produce photosensitive resin 2.

The manufactured photosensitive resin 2 was confirmed to have an acrylic equivalent of 401 g/eq, a solid acid value of 56 mgKOH/g, and a solid content of 64%.

Synthesis Example 3: Photosensitive Resin 3

In the above Synthesis Example 1, the amount of cresol novolac epoxy resin was changed to 386 g, acrylic acid to 100 g, dimethylolpropionic acid to 48 g, and tetrahydrophthalic anhydride to 8 g during the epoxy addition reaction, thereby producing an intermediate compound solution having a molar ratio of the first hydroxyl group:the second hydroxyl group of 4:10, and the amount of tetrahydrophthalic anhydride was changed to 96 g during the acid anhydride addition reaction, thereby producing a photosensitive resin 3 in the same manner as in Synthesis Example 1.

The manufactured photosensitive resin 3 was confirmed to have an acrylic equivalent of 461 g/eq, a solid acid value of 55.3 mgKOH/g, and a solid content of 64%.

Synthesis Example 4: Photosensitive Resin 4

In the above Synthetic Example 1, the amount of cresol novolac epoxy resin was changed to 380 g, acrylic acid to 85 g, dimethylolpropionic acid to 71 g, and tetrahydrophthalic anhydride to 8 g during the epoxy addition reaction, thereby producing an intermediate compound solution having a molar ratio of the first hydroxyl group:the second hydroxyl group of 6:10, and the amount of tetrahydrophthalic anhydride was changed to 94 g during the acid anhydride addition reaction, thereby producing a photosensitive resin 4 in the same manner as in the above Synthetic Example 1.

The manufactured photosensitive resin 4 was confirmed to have an acrylic equivalent of 539 g/eq, a solid acid value of 54.4 mgKOH/g, and a solid content of 64%.

Synthesis Example 5: Photosensitive Resin 5

In the above Synthesis Example 1, the amount of cresol novolac epoxy resin, 91 g of acrylic acid, and 93 g of dimethylolpropionic acid were changed to 373 g for the epoxy addition reaction, thereby producing an intermediate compound solution having a molar ratio of the first hydroxyl group:the second hydroxyl group of 8:10, and the amount of tetrahydrophthalic anhydride was changed to 92 g for the acid anhydride addition reaction, respectively, thereby producing a photosensitive resin 5 in the same manner as in Synthesis Example 1.

The manufactured photosensitive resin 5 was confirmed to have an acrylic equivalent of 645 g/eq, a solid acid value of 53.4 mgKOH/g, and a solid content of 64%.

Synthesis Example 6: Photosensitive Resin 6

In the above Synthetic Example 1, dimethylolpropionic acid was not added during the epoxy addition reaction, and 403 g of cresol novolac epoxy resin and 135 g of acrylic acid were added, thereby producing an intermediate compound solution having a molar ratio of the first hydroxyl group:the second hydroxyl group of 0:10, and 100 g of tetrahydrophthalic anhydride was added during the acid anhydride addition reaction, except that the same method as Synthetic Example 1 was performed to produce a photosensitive resin 6.

The manufactured photosensitive resin 6 was confirmed to have an acrylic equivalent of 340 g/eq, a solid acid value of 58 mgKOH/g, and a solid content of 64%.

Synthesis Example 7: Photosensitive Resin 7

In the above Synthetic Example 1, except that during the epoxy addition reaction, dimethylolpropionic acid was not added, 378 g of cresol novolac epoxy resin and 127 g of acrylic acid were changed to be added, thereby producing an intermediate compound solution having a molar ratio of the first hydroxyl group:the second hydroxyl group of 0:10, and during the acid anhydride addition reaction, tetrahydrophthalic anhydride was changed to be added 134 g, the same method as in Synthetic Example 1 was performed to produce a photosensitive resin 7.

The manufactured photosensitive resin 7 was confirmed to have an acrylic equivalent of 363 g/eq, a solid acid value of 77 mgKOH/g, and a solid content of 64%.

Synthesis Example 8: Photosensitive Resin 8

In a reactor equipped with a stirrer, a thermometer, an air inlet pipe, and an oil-water separator, 450 g of cresol novolac resin to which ethylene oxide was added, 56 g of acrylic acid, 15 g of methanesulfonic acid, 0.5 g of methylhydroquinone, 1 g of dibutylhydroxytoluene, and 450 g of toluene were charged, and air was blown in and the mixture was reacted at 105 to 120°C for 8 hours while stirring. At the same time, the condensed water generated during the reaction was separated through an oil-water separator. A total of 20.5 g of condensed water was generated here. Then, after cooling to 50°C, the reaction solution was neutralized with a 5% NaoH aqueous solution and washed three times with a 15% NaCl aqueous solution. Thereafter, toluene was distilled off by replacing it with carbitol acetate and solvent naphtha in an evaporator, thereby obtaining an intermediate compound solution.

To 500 g of the obtained intermediate compound solution, 100 g of tetrahydrophthalic anhydride, 2 g of triphenylphosphine, 50 g of carbitol acetate, and 50 g of solvent naphtha were added, and the mixture was reacted at 95 to 100°C for 8 hours while blowing air. After confirming that the absorption spectrum of the acid anhydride disappeared in IR, the mixture was cooled to produce photosensitive resin 8, which is a cresol novolac-based photosensitive resin to which ethylene oxide is added.

The manufactured photosensitive resin 8 was confirmed to have an acrylic equivalent of 539 g/eq, a solid acid value of 83 mgKOH/g, and a solid content of 60%.

[Experimental Example 1-9]

A solder resist composition for each experimental example was prepared by mixing each component according to the compositions described in Table 1 and Table 2 below.

Ingredients (weight%) Experimental Example 1 Experimental example 2 Experimental Example 3 Experimental Example 4 Experimental Example 5 Photosensitive resin 1 25 - - - - Photosensitive resin 2 - 25 - - - Photosensitive resin 3 - - 25 20 - Photosensitive resin 4 - - - - 25 Photosensitive resin 5 - - - - - Photosensitive resin 6 - - - - - Photosensitive resin 7 - - - - - Photosensitive resin 8 15 15 15 20 15 Epoxy resin 1 5 5 5 5 5 Epoxy resin 2 3 3 3 3 3 acryl 5 5 5 5 5 hydrophobic oligomer 4.5 4.5 4.5 4.5 4.5 Photon initiator 2.5 2.5 2.5 2.5 2.5 reaction catalyst 0.4 0.4 0.4 0.4 0.4 Filler 28 28 28 28 28 Ion Catcher 0.5 0.5 0.5 0.5 0.5 Pigment 1 0.1 0.1 0.1 0.1 0.1 Pigment 2 0.5 0.5 0.5 0.5 0.5 Dispersant 1.5 1.5 1.5 1.5 1.5 Solvent 1 4.5 4.5 4.5 4.5 4.5 Solvent 2 4.5 4.5 4.5 4.5 4.5 Total amount 100.0 100.0 100.0 100.0 100.0

Ingredients (weight%) Experimental example 6 Experimental example 7 Experimental example 8 Experimental Example 9 Photosensitive resin 1 - - - - Photosensitive resin 2 - - - - Photosensitive resin 3 - - - - Photosensitive resin 4 - - - - Photosensitive resin 5 25 - - - Photosensitive resin 6 - 25 - - Photosensitive resin 7 - - 25 - Photosensitive resin 8 15 15 15 41 Epoxy resin 1 5 5 5 5 Epoxy resin 2 3 3 3 3 acryl 5 5 5 5 hydrophobic oligomer 4.5 4.5 4.5 4.5 Photon initiator 2.5 2.5 2.5 2.5 reaction catalyst 0.4 0.4 0.4 0.4 Filler 28 28 28 28 Ion Catcher 0.5 0.5 0.5 0.5 Pigment 1 0.1 0.1 0.1 0.1 Pigment 2 0.5 0.5 0.5 0.5 Dispersant 1.5 1.5 1.5 1.5 Solvent 1 4.5 4.5 4.5 4 Solvent 2 4.5 4.5 4.5 4 Total amount 100.0 100.0 100.0 100.0

Photosensitive resin 1: Photosensitive resin of synthesis example 1

Photosensitive resin 2: Photosensitive resin of synthesis example 2

Photosensitive resin 3: Photosensitive resin of synthesis example 3

Photosensitive resin 4: Photosensitive resin of synthesis example 4

Photosensitive resin 5: Photosensitive resin of synthesis example 5

Photosensitive resin 6: Photosensitive resin of synthesis example 6

Photosensitive resin 7: Photosensitive resin of synthesis example 7

Photosensitive resin 8: Photosensitive resin of synthesis example 8

Epoxy resin 1: Bisphenol A type epoxy resin (Cas no. 25068-38-6, EEW 450-500 g/eq, Mw 2,000)

Epoxy resin 2: Biphenyl epoxy resin (Cas no. 89118-70-7, EEW 180 g/eq, Mw 354)

Acrylic: DPHA (Dipentaerythritol hexa acrylate)

Hydrophobic oligomer: Epoxidized polybutadiene resin (PB3600, EEW 193 g/eq)

Photoinitiator: 2-Benzyl-2-dimethylamino-1-(4-morpholino-phenyl)-1-butanone (Irgacure 369)

Reaction catalyst: Melamine

Filler: Barium sulfate

Ion catcher: A mixture of Mg ₆ Al ₂ [(OH) ₁₆ CO ₃ ]*4H ₂ O 70% and Zr(HPO ₄ ) ₂ 30%

Pigment 1: Azo pigment

Pigment 2: Phthalocyanine pigment

Dispersant: BYK 110

Solvent 1: Dipropylene glycol monomethyl ether

Solvent 2: Solvent naphtha (Kocosol-150)

[Property Evaluation]

The properties of the solder resist composition manufactured according to each experimental example were measured using the following method, and the results are shown in Table 3 below.

Sensitivity

The solder resist composition manufactured in each experimental example was applied on a substrate by a screen printing method, dried at 80°C for 30 minutes, and cooled at room temperature. A 41-step tablet for sensitivity evaluation was pressed onto the dried coating layer, and exposed at an intensity of 700 mJ/cm2 through an exposure device equipped with a high-pressure mercury lamp, developed with a 1% sodium carbonate aqueous solution at 30°C for 90 seconds, and rinsed with water. Thereafter, the sensitivity evaluation was performed by observing the largest step in the gloss phase.

phenomenon time

The solder resist composition manufactured in each experimental example was applied to a substrate by screen printing, dried at 80°C for 40 minutes, and cooled to room temperature. Afterwards, the time until no residue remained, i.e. the developing time (seconds), was measured while developing with a 1% sodium carbonate aqueous solution at 30°C.

Marine

The solder resist composition manufactured in each experimental example was applied to the substrate by the screen printing method, dried at 80°C for 30 minutes, and cooled at room temperature. Thereafter, a film for a pattern mask was pressed onto the substrate, exposed at 900 mJ/ ^cm2 through an exposure device equipped with a high-pressure mercury lamp, developed with a 1% sodium carbonate aqueous solution at 30°C for 90 seconds, and washed with water to form a pattern. Here, the minimum opening size (㎛) that maintained the shape of a circle was measured and expressed as the resolution.

Undercut

In each experimental example, the manufactured solder resist composition was applied onto a substrate by a screen printing method, dried at 80° C. for 30 minutes, and cooled at room temperature. A pattern mask film having an SR Dam (width: 100 μm) formed thereon was pressed onto the dried substrate, exposed at an intensity of 900 mJ/cm2 through an exposure device equipped with a high-pressure mercury lamp, developed in a 1% sodium carbonate aqueous solution at 30° C. for 90 seconds, and rinsed with water. Thereafter, it was heat-cured in a hot air oven at 150° C. for 1 hour, and then additionally exposed at an intensity of 1,200 mJ/cm2 through an exposure device equipped with a high-pressure mercury lamp. The substrate manufactured by the above method was cut with scissors at the part where the SR Dam (width 100 ㎛) was formed, molded with a molding liquid, and the cross-section of the Dam was polished. Then, the undercut was measured a total of 10 times using a microscope (magnification X 500) and the average value (㎛) was recorded.

Tack-free property

The solder resist composition manufactured in each experimental example was applied onto a substrate by screen printing, dried at 80° C. for 30 minutes, and cooled to room temperature to manufacture an evaluation substrate.

A film for a pattern mask was pressed onto a portion of the above evaluation substrate, pressure was applied for 1 minute using a 3 kg weight, and when the film was peeled off, the degree of film sticking, i.e. the degree of occurrence of film marks, was evaluated according to the following criteria.

[metewand]

◎: No resistance when peeling the film, and no film marks on the coating

○: There is no resistance when the film is peeled off, film marks occur in a small area (less than 20% of the total area) on the coating, and are not easily visible.

△: There is a slight resistance when peeling the film, the area of the film mark occurs in the middle area (20% or more and less than 40% of the total area), and visibility is at an average level.

X: There is resistance when the film is peeled off, and the film marks occur over a large area (more than 40% of the total area) on the coating, and are easily visible.

HAST resistance

The solder resist composition manufactured in each experimental example was applied to a BT substrate on which electrodes (line space = 30 μm) were formed using a screen printing method, dried at 80° C. for 30 minutes, and cooled to room temperature to manufacture an evaluation substrate.

The HAST evaluation was conducted for 168 hours by applying a voltage of 5 V to the above evaluation board under high temperature conditions of 130°C and high humidity of 85%. After 168 hours, the insulation resistance value was evaluated according to the following criteria.

[metewand]

○: 10 ⁸ Ω or more

△: 10 ⁶ ~ 10 ⁸ Ω

X: 10 ⁶ Ω or less

Cu migration

The solder resist composition manufactured in each experimental example was applied to a BT substrate on which electrodes (line space = 30 μm) were formed using a screen printing method, dried at 80° C. for 30 minutes, and cooled to room temperature to manufacture an evaluation substrate.

The above evaluation board was subjected to a HAST evaluation for 168 hours at a high temperature of 130°C and a high humidity of 85%, with a voltage of 5 V applied. After 168 hours, the evaluation board was cut with scissors, molded with a molding solution, and the cross-section was polished. The degree of Cu ion generation was visually confirmed using a microscope (×500 magnification), and evaluated according to the following criteria.

[metewand]

○: No generation of Cu ions

△: Slight generation of Cu ions

X: Large amount of Cu ions generated

Sensitivity
(step) phenomenon time
(candle) Resolution (㎛) Undercut (㎛) Film pressure HAST resistance Cu migration Experimental Example 1 21 49 70 4.9 O O O Experimental example 2 21 55 65 4.2 ◎ O O Experimental Example 3 20 52 60 2.1 ◎ O O Experimental Example 4 18 60 65 3.7 ◎ O O Experimental Example 5 18 54 55 2.3 ◎ O O Experimental example 6 15 61 60 2.7 O O O Experimental Example 7 22 77 90 8.6 △ O O Experimental example 8 20 58 80 7.2 △ O O Experimental Example 9 15 60 65 4.9 X O O

As shown in Table 3 above, the solder resist compositions of Experimental Examples 1 to 5 including the epoxy resin-based acid-modified epoxy acrylate resin (photosensitive resin 1-4) according to the present invention exhibited excellent properties in all measured items. On the other hand, the solder resist compositions of Experimental Examples 6 to 8 using the epoxy resin-based acid-modified epoxy acrylate resin (photosensitive resin 5-7) prepared from an intermediate compound having a molar ratio of primary hydroxyl groups and secondary hydroxyl groups outside the range of the present invention, and Experimental Example 9 not including the epoxy resin-based acid-modified epoxy acrylate resin, exhibited properties inferior to those of Experimental Examples 1 to 5 in all measured items.

Claims (7)

Containing photosensitive resin, epoxy resin, acrylic, photoinitiator and filler,
The above photosensitive resin includes an epoxy resin-based acid-modified epoxy acrylate resin,
The above epoxy resin-based acid-modified epoxy acrylate resin is manufactured by adding an acid anhydride to an intermediate compound manufactured by reacting an epoxy resin with a carboxyl compound containing a hydroxyl group.
The above intermediate compound is prepared by reacting 0.05 to 0.35 equivalents of a carboxyl compound containing a primary hydroxyl group, 0.65 to 0.95 equivalents of a carboxyl compound containing an unsaturated group, and 0.01 to 0.05 equivalents of an acid anhydride with respect to 1 equivalent of an epoxy group of an epoxy resin.
The molar ratio of the primary hydroxyl group and the secondary hydroxyl group of the above intermediate compound is 2:10 to 6:10,
A solder resist composition wherein the above acid-modified epoxy acrylate resin is prepared by adding 0.2 to 0.8 equivalents of an acid anhydride to the above intermediate compound solution. In the first paragraph,
A solder resist composition wherein the above epoxy resin-based acid-modified epoxy acrylate resin has a solid acid value of 50 to 100 mgKOH/g and an acrylic equivalent of 200 to 600 g/eq. delete In the first paragraph,
The above photosensitive resin further comprises an acid-modified acrylate resin based on an alkylene oxide addition novolac resin,
A solder resist composition wherein the acid-modified acrylate resin based on the above alkylene oxide addition novolac resin has a chloride ion content of less than 30 ppm and a solid acid value of 50 to 100 mgKOH/g. In paragraph 4,
The above-mentioned alkylene oxide addition novolac resin-based acid-modified acrylate resin is a solder resist composition manufactured by adding an acid anhydride to an intermediate compound manufactured by reacting an alkylene oxide addition novolac resin with a carboxyl compound containing an unsaturated group. In paragraph 4,
The above photosensitive resin includes a first photosensitive resin and a second photosensitive resin,
The above first photosensitive resin comprises an epoxy resin-based acid-modified epoxy acrylate resin,
The above second photosensitive resin comprises an acid-modified acrylate resin based on the above alkylene oxide addition novolac resin,
A solder resist composition wherein the mixing ratio of the first photosensitive resin and the second photosensitive resin is 40:60 to 90:10 by weight. In the first paragraph,
A solder resist composition comprising 30 to 50 wt% of the photosensitive resin, 1 to 30 wt% of the epoxy resin, 1 to 10 wt% of the acrylic, 1 to 15 wt% of the photoinitiator, and 20 to 40 wt% of the filler, based on the total weight of the solder resist composition.