TWI756509B - Positive-type photosensitive resin composition and insulation layer formed from the same and image display device - Google Patents

Abstract

The present invention provides a positive-type photosensitive resin composition, an insulation layer, and an image display device. The positive-type photosensitive resin composition comprises a binder resin, an antioxidant containing a bifunctional epoxy compound, a photoacid generator, and a solvent. The insulating film having improved transmittance and reliability can be formed through the interaction of the binder resin and the antioxidant.

Description

Positive photosensitive resin composition, insulating film formed therefrom, and image display device

The present invention relates to a positive-type photosensitive resin composition, an insulating film produced from the positive-type photosensitive resin composition, and an image display device including the insulating film. More specifically, it relates to a positive photosensitive resin composition including a photosensitive resin and a photoacid generator, an insulating film produced from the positive photosensitive resin composition, and an image display device including the insulating film.

For example, a photosensitive resin composition is used in order to form various photocurable insulating patterns such as photoresists, insulating films, protective films, black matrices, and column spacers of display devices. For example, inorganic insulating films such as silicon oxides and silicon nitrides have high dielectric constants, and there is an increasing demand for low-dielectric organic insulating films. To form the organic insulating films, the photosensitive resin compositions described above can be used.

The organic insulating film can be formed into a predetermined pattern by applying the photosensitive resin composition, curing it by preheating, and then performing exposure and development processes.

The above-mentioned photosensitive resin composition is classified into positive type and negative type according to the part removed after the development process. In the case of a positive-type composition, the exposed part is dissolved by the developer, and in the case of a negative-type composition, the unexposed part is dissolved and a pattern can be formed.

In the case of the above-mentioned organic insulating film, it is necessary to form the above-mentioned photosensitive resin combination so as to have excellent insulating properties and to have mechanical properties such as heat resistance, and to have excellent sensitivity to the above-mentioned exposure process. thing.

In addition, due to the above-mentioned heat treatment, the optical properties of the above-mentioned organic insulating film may be changed, resulting in a decrease in transmittance, thereby deteriorating the image quality of the display device. Therefore, it is also necessary to design the above-mentioned photosensitive resin composition in consideration of the optical properties of the above-mentioned organic insulating film.

For example, Korean Laid-Open Patent Publication No. 2013-0021324 discloses a positive resist composition, but fails to provide a solution for improving the above-mentioned mechanical and optical properties.

prior art literature

Patent Literature

Korean Laid-Open Patent No. 10-2013-0021324.

problem to be solved

An object of the present invention is to provide a photosensitive resin composition having excellent chemical, optical, and mechanical properties.

An object of the present invention is to provide an insulating film formed from the above-mentioned photosensitive resin composition and having excellent transmittance and reliability.

An object of the present invention is to provide an image display device including an insulating film formed from the above-mentioned photosensitive resin composition.

solution to the problem

1. A positive photosensitive resin composition comprising: a binder resin, an antioxidant containing a bifunctional epoxy compound, a photoacid generator and a solvent.

2. The positive photosensitive resin composition according to 1, wherein the binder resin includes a first resin containing a phenol unit protected by an acid-decomposable group.

3. The positive photosensitive resin composition as described in 1, the above-mentioned first resin comprises a structural unit represented by the following chemical formula 1:

[Chemical formula 1]

(In Chemical Formula 1, R ₁ and R ₂ are each independently hydrogen or methyl, and R ₃ represents the above-mentioned acid-decomposable group, and is substituted or unsubstituted with an alkyl group having 1 to 6 carbon atoms. ~10 alkyl group, tetrahydropyranyl group, or C1~10 alkyl group substituted or unsubstituted by C1~6 alkoxy group or C4~8 cycloalkoxy group , p is 40 ~ 80 mol%, q is 20 ~ 60 mol%).

4. The positive photosensitive resin composition as described in 3, the above-mentioned first resin comprises a structural unit represented by the following chemical formula 1-1:

[Chemical formula 1-1]

(In Chemical Formula 1-1, R ₁ and R ₂ are each independently hydrogen or methyl, R ₄ and R ₅ are each independently an alkyl group having 1 to 6 carbon atoms, p is 40 to 80 mol%, and q 20 to 60 mol%).

5. The positive photosensitive resin composition according to 2, wherein the binder resin further includes at least one of a second resin and a third resin, the second resin includes an epoxy group-containing acrylic resin, and the third Resins include oxetanyl-containing acrylic resins.

6. The positive photosensitive resin composition as described in 5, wherein the second resin is derived from at least one of the monomers represented by the following chemical formula 2 and chemical formula 3:

[Chemical formula 2]

[Chemical formula 3]

(in chemical formulas 2 and 3, Z ₁ is hydrogen or methyl, Z ₂ is an alkylene group with 1 to 6 carbon atoms, Z ₃ and Z ₄ are independently hydrogen or an alkyl group with 1 to 6 carbon atoms, Or connected to each other to form a ring with 3 to 8 carbon atoms, m is an integer of 1 to 6).

7. The positive photosensitive resin composition as described in 5, wherein the above-mentioned third resin comprises a structural unit derived from a monomer represented by the following chemical formula 4:

[Chemical formula 4]

(In Chemical Formula 4, Ra is hydrogen or a methyl group, Rb is an alkylene group having 1 to 6 carbon atoms, and Rc is an alkyl group having 1 to 6 carbon atoms).

8. The positive photosensitive resin composition as described in 5, wherein the total 100 parts by weight of the above-mentioned binder resin includes about 30 to 55 parts by weight of the above-mentioned first resin, about 30 to 60 parts by weight of the above-mentioned second resin and the above-mentioned first resin. The three resins are about 1 to 25 parts by weight.

9. positive photosensitive resin composition as described in 1, above-mentioned antioxidant comprises the compound represented by following chemical formula 5:

[Chemical formula 5]

(In Chemical Formula 5, R ₁ is an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group having 3 to 12 carbon atoms).

10. The positive photosensitive resin composition as described in 9, the above-mentioned antioxidant comprises a compound represented by the following chemical formula 5-1:

[Chemical formula 5-1]

。

.

11. The positive photosensitive resin composition according to 1, wherein in the total weight of the composition, the content of the above-mentioned binder resin is 5 to 50% by weight, and in 100 parts by weight of the above-mentioned binder resin, the content of the above-mentioned antioxidant is 1 ~ 10 parts by weight.

12. The positive-type photosensitive resin composition according to 1, wherein the photoacid generator is selected from the group consisting of diazonium salts, phosphonium salts, periconium salts, iodonium salts, imidosulfonates, oximes. At least one of the group consisting of sulfonate-based, diazobis-based, bis-based, o-nitrobenzyl sulfonate-based and triazine-based compounds.

13. An insulating film formed from the positive photosensitive resin composition according to any one of 1 to 12 above.

14. The insulating film according to 13, which is used as an interlayer insulating film or a through-hole insulating film of an image display device.

15. An image display device comprising the insulating film described in 13 above.

Invention effect

The photosensitive resin composition of the exemplary embodiment includes an antioxidant containing a bifunctional epoxy-based compound, and can prevent the yellowing phenomenon from being oxidized by heat treatment such as post-baking of phenol gene. Therefore, an insulating film that maintains excellent transparency even after curing can be formed.

In addition, the above-mentioned antioxidant can further improve film properties such as the adhesiveness and coatability of the above-mentioned insulating film.

The binder resin of the above-mentioned photosensitive resin composition includes a first resin containing a hydroxyl group and a protective group, and may further include a second resin containing an epoxy group and/or a third resin containing an oxetanyl group. The above-mentioned first resin can ensure the sensitivity of the exposure process and the resolution of the development process, and the above-mentioned second resin and/or third resin can improve the curing characteristics and mechanical characteristics of the insulating film.

In order to have a better understanding of the above-mentioned and other aspects of the present invention, the following specific examples are given and described in detail in conjunction with the accompanying drawings as follows:

Embodiments of the present invention provide a positive-type photosensitive resin composition, which includes a binder resin, an antioxidant containing a bifunctional epoxy compound, a photoacid generator and a solvent, and has excellent transmittance and film formation reliability. Furthermore, there are provided an insulating film formed from the above-mentioned positive-type photosensitive resin composition, and an image display device including the above-mentioned insulating film.

Hereinafter, the Example of this invention is demonstrated in detail.

<Positive type photosensitive resin composition>

The positive-type photosensitive resin composition of the embodiment of the present invention (hereinafter, may also be simply referred to as a photosensitive composition) may include a binder resin, an antioxidant, a photoacid generator, and a solvent.

According to an exemplary embodiment, the above-mentioned photosensitive composition may be provided as, for example, a chemically amplified resist (CAR) composition whose solubility is different due to an acid generated by an exposure process. Therefore, an insulating film or an insulating pattern can be formed with improved sensitivity and resolution as compared with a photoactive compound (Photo Active Compound: PAC)-based composition such as diazoquinone.

adhesive resin

The photosensitive composition of the exemplary embodiment may include a binder resin as a base component. The above-mentioned binder resin can provide the basic skeleton of the insulating film formed from the above-mentioned photosensitive composition, and can provide the solubility difference after the exposure process.

According to an exemplary embodiment, the above-mentioned binder resin includes a first resin containing a phenol-based (or novolac-based) resin, and may further include a second resin and/or a third resin, the second resin includes an epoxy group-containing resin The acrylic resin described above, the third resin comprises an oxetane group-containing acrylic resin.

The above-mentioned first resin may include a plurality of hydroxyl groups, and at least a part of the above-mentioned hydroxyl groups may be protected by an acid-decomposable group. For example, among the phenol units included in the first resin, the hydroxyl groups included in at least a part of the phenol units may be protected by the acid-decomposable groups.

For example, the above-mentioned first resin may include a structural unit (eg, repeating unit) represented by the following Chemical Formula 1.

[Chemical formula 1]

In Chemical Formula 1, R ₁ and R ₂ may each independently represent hydrogen or methyl. R ₃ represents the above acid-decomposable group, and may represent an alkyl group having 1 to 10 carbon atoms substituted or unsubstituted with an alkyl group having 1 to 6 carbon atoms, a tetrahydropyranyl group, or an alkyl group having 1 to 1 carbon atoms. A substituted or unsubstituted alkyl group of 1 to 10 carbon atoms with an alkoxy group of ~ 6 or a cycloalkoxy group of 4 to 8 carbon atoms.

p and q may respectively represent the molar ratio of the phenol unit to the phenol unit protected by the acid-decomposable group. For example, p can be about 40-80 mol%, and q can be about 20-60 mol%. p and q represent the relative molar ratio of the above-mentioned phenol unit to the phenol unit protected by the acid-decomposable group, and the addition of other units is not excluded.

In some embodiments, the above-mentioned first resin may include a structure represented by the following Chemical Formula 1-1.

[Chemical formula 1-1]

R ₁ , R ₂ , p and q are the same as defined in Chemical Formula 1 above. R ₄ and R ₅ may each independently represent an alkyl group having 1 to 6 carbon atoms.

For example, the above-mentioned phenol unit may be derived from hydroxystyrene as the first monomer. The phenol unit protected by the acid-decomposable group can be derived from the following chemical formula 1-2, and in one embodiment, can be derived from the second monomer represented by the chemical formula 1-3.

[Chemical formula 1-2]

[Chemical formula 1-3]

In Chemical Formulae 1-2 and 1-3, R ₃ , R ₄ and R ₅ are the same as defined in Chemical Formulae 1 and 1-1 above.

The first resin can be produced by the copolymerization reaction of the first monomer and the second monomer, and the molar numbers of the first monomer and the second monomer can be adjusted to correspond to desired p and q. of Morby.

As described above, the first resin can achieve both the sensitivity to the exposure process and the adhesion to the substrate through both a phenol unit including a residual hydroxyl group and a phenol unit protected by an acid-decomposable group.

In some embodiments, the first resin may further include a unit derived from a third monomer in addition to the first monomer and the second monomer. The above-mentioned third monomer may include, for example, a (meth)acrylate-based monomer. In this case, non-limiting examples of the third monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, and isopropyl (meth)acrylate. Propyl, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate and other alkyl (meth)acrylates; ( Cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methylcyclohexyl (meth)acrylate, 2-dicyclopentyloxyethyl (meth)acrylate, (meth)acrylic acid Alicyclic (meth)acrylates such as isobornyl ester; aryl (meth)acrylates such as phenyl (meth)acrylate, benzyl (meth)acrylate, and the like.

The above-mentioned third monomer may also include a hydroxyl group-containing monomer. In this case, the third monomer may include, for example, an ethylenically unsaturated monomer having a carboxyl group such as acrylic acid, methylolstyrene, and the like.

In some embodiments, the weight average molecular weight of the first resin may be 5,000-35,000, preferably 5,000-20,000. Within the above range, the film retention rate of the photosensitive composition can be effectively improved and film residues can be reduced.

The above-mentioned binder resin may further include an epoxy group-containing acrylic resin as the above-mentioned second resin. By including the above-mentioned second resin, for example, thermosetting properties can be improved in a heat treatment process such as post-baking, thereby further improving mechanical properties such as heat resistance and impact resistance of the insulating film.

In some embodiments, the second resin may be derived from a monomer represented by the following chemical formula 2.

[Chemical formula 2]

In Chemical Formula 2, Z ₁ may be hydrogen or methyl, and Z ₂ may be an alkylene group having 1 to 6 carbon atoms. Z ₃ and Z ₄ independently of each other may be hydrogen or an alkyl group having 1 to 6 carbon atoms, and may be connected to each other to form a ring having 3 to 8 carbon atoms. m can be an integer from 1 to 6.

In the monomer represented by the above chemical formula 2, Z ₂ can form an ether bond through an adjacent oxygen atom. Thereby, since the rotation through the ether bond can be performed, the glass transition temperature can be reduced and the fluidity of the photosensitive composition can be improved.

In addition, in the above Chemical Formula 2, the monomer length can be adjusted by adjusting m. By adjusting the above-mentioned monomer length, the sidewall slope of the insulating pattern generated after the developing process can be adjusted. For example, when a subsequent conductive pattern such as a transparent electrode is formed by reducing the slope of the side wall, damage to the insulating pattern and peeling of the conductive pattern can be prevented.

In some embodiments, the second resin may be derived from a monomer represented by the following chemical formula 3.

[Chemical formula 3]

In Chemical Formula 3, Z ₁ , Z ₃ , Z ₃ and Z ₄ are the same as defined in Chemical Formula 2 above.

Through the monomer represented by the above-mentioned chemical formula 3, the penetration rate of the above-mentioned second resin can be further improved.

In some embodiments, the second resin described above may be produced using at least one of the monomer of Chemical Formula 2 and the monomer of Chemical Formula 3.

The said 2nd resin can be manufactured by copolymerizing other monomers used in this technical field which can form an acrylic resin other than the monomer represented by Chemical formula 2 or Chemical formula 3.

In some embodiments, the other monomers mentioned above may include carboxyl group-containing ethylenically unsaturated monomers to improve developability and adhesion to substrates. Examples of the aforementioned carboxyl group-containing ethylenically unsaturated monomers include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; dicarboxylic acids such as fumaric acid, mesaconic acid, and itaconic acid, and acid anhydrides thereof. .

Non-limiting examples of the addition of the above-mentioned other monomers include styrene, vinyltoluene, methylstyrene, p-chlorostyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene Aromatic vinyl compounds such as styrene, o-vinylbenzyl methyl ether, m-vinylbenzyl methyl ether, p-vinylbenzyl methyl ether; N-cyclohexylmaleimide, N-benzyl N-phenylmaleimide, N-phenylmaleimide, N-o-hydroxyphenylmaleimide, N-m-hydroxyphenylmaleimide, N-p-hydroxyphenylmaleimide Imine, N-o-methylphenylmaleimide, N-m-methylphenylmaleimide, N-p-methylphenylmaleimide, N-o-methoxyphenyl Maleimide, N-m-methoxyphenylmaleimide, N-p-methoxyphenylmaleimide and other N-substituted maleimide compounds; (meth)acrylic acid Methyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylate ) Alkyl (meth)acrylates such as sec-butyl acrylate and tert-butyl (meth)acrylate; cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-(meth)acrylate Alicyclic (meth)acrylates such as methylcyclohexyl, 2-dicyclopentyloxyethyl (meth)acrylate, and isobornyl (meth)acrylate; phenyl (meth)acrylate, ( Aryl (meth)acrylates such as benzyl meth)acrylate; 3-(methacryloyloxymethyl)oxetane, 3-(methacryloyloxymethyl)-3- Ethyloxetane, 3-(methacryloyloxymethyl)-2-trifluoromethyloxetane, 3-(methacryloyloxymethyl)-2-phenyl oxetane, 2-(methacryloyloxymethyl)oxetane, 2-(methacryloyloxymethyl)-4-trifluoromethyl oxetane, etc. Saturated oxetane compounds, etc. These can be used alone or in combination of two or more.

For example, the above-mentioned second resin can be produced by copolymerizing at least one of the monomer represented by Chemical Formula 2 or Chemical Formula 3 and the other monomers described above. The molar ratio of the monomer represented by Chemical Formula 2 or Chemical Formula 3 may be about 5 to 60 mol % in the total monomer. In this case, the improvement of developability, transparency, pattern slope, etc. through the second resin can be effectively achieved.

The weight average molecular weight of the second resin may be 5,000 to 40,000, preferably 15,000 to 30,000. Within the above range, developability can be further improved, and film residues can be reduced.

In some embodiments, the third resin may further include an oxetanyl group-containing acrylic resin (eg, a third resin). In this case, the thermal curing process can be accelerated by the cross-linking reaction through the oxetanyl group.

The above-mentioned third resin may include, for example, a structural unit derived from a monomer represented by the following Chemical Formula 4.

[Chemical formula 4]

In Chemical Formula 4, Ra may be hydrogen or methyl. Rb may be an alkylene group having 1 to 6 carbon atoms, and Rc may be an alkyl group having 1 to 6 carbon atoms.

In some embodiments, the third resin may further include a structural unit derived from at least one of the monomers represented by the following formulae (1) to (3).

In some embodiments, the above-mentioned third resin may further comprise sources derived from (meth)acrylic acid, 2-(meth)acryloyloxyethyl succinate, and 2-(meth)acryloyl hexahydrophthalate. A structural unit of at least one of oxyethyl ester, 2-(meth)acryloyloxyethyl phthalate, or 2-(meth)acryloyloxyethyl succinate.

The weight average molecular weight of the third resin may be 5,000 to 30,000, preferably 8,000 to 20,000. Within the above range, developability and stability over time can be improved, and film residues after development can be reduced.

In some embodiments, the above-mentioned binder resin may comprise a mixture of the above-mentioned first resin, second resin and third resin. In this case, with respect to 100 parts by weight of the above-mentioned binder resin, about 30-55 parts by weight of the above-mentioned first resin, about 30-60 parts by weight of the above-mentioned second resin, and about 1-25 parts by weight of the above-mentioned third resin can be included.

In an exemplary embodiment, in the total weight of the photosensitive composition, the content of the binder resin may be about 5 to 50% by weight, preferably about 10 to 40% by weight. Within the above range, the sensitivity to the exposure process and the resolution to the development process can be simultaneously improved.

Antioxidants

The said photosensitive composition contains an antioxidant, and can suppress the denaturation and oxidation by the oxidation of the said binder resin.

The above-mentioned antioxidant may be contained in the form of a monomer, and may function as a protective agent for the phenol unit or hydroxyl group contained in the above-mentioned binder resin. According to an exemplary embodiment, the above-mentioned antioxidant may include a bifunctional epoxy-based compound. For example, the antioxidant may have a structure in which an epoxy group is bonded to the terminal through a linking group.

In some embodiments, the above-mentioned antioxidant may include a compound represented by the following Chemical Formula 5.

[Chemical formula 5]

In Chemical Formula 5, R1 may represent an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group having 3 to 12 carbon atoms. When R1 is an alkylene group, it may be linear or branched, and when it is a branched chain, the number of carbon atoms may be 3 to 6.

In one embodiment, the above-mentioned antioxidant may include a compound represented by the following chemical formula 5-1.

[Chemical formula 5-1]

The above-mentioned antioxidants can prevent, for example, the problem of oxidation and denaturation of phenol units generated by detachment of phenol units or acid-decomposable groups to quinones in post-baking processes after exposure and development processes or subsequent heat treatment processes. When the above-mentioned binder resin is denatured and contains quinone, a yellowish phenomenon of the insulating film can be induced, and the transmittance of the insulating film can be lowered.

For example, the above-mentioned antioxidant can combine with the hydroxyl group exposed by the above-mentioned phenol unit through the epoxy group after the above-mentioned exposure and development process, thereby inhibiting oxidative denaturation into the above-mentioned quinone unit. Therefore, the desired transparency and transmittance of the above-mentioned insulating film can be maintained even after the above-mentioned post-baking or subsequent heat treatment process.

The above-mentioned antioxidant includes, for example, an epoxy group at the terminal through a linear linking group, so that it can easily meet with the hydroxyl group of the adjacent binder resin without steric hindrance. When the length of the above-mentioned linear linking group is excessively increased, the possibility of reaction or interaction with the above-mentioned hydroxyl group may be reduced due to molecular folding or the like. Moreover, when the number of epoxy functional groups of the said antioxidant is 3 or more, a molecular structure will become bulky (bulky), and the possibility of bonding with the hydroxyl group of the said binder resin may fall on the contrary.

The said antioxidant can improve the adhesiveness of a composition by interacting with the hydroxyl group contained in a binder resin as mentioned above. In addition, as represented by Chemical Formula 5, the fluidity of the composition can be improved through a rotatable structure such as an ether bond such as an ethylene oxide (EO) group, thereby simultaneously increasing coatability, flatness, and the like. Film forming properties.

In an exemplary embodiment, with respect to 100 parts by weight of the above-mentioned binder resin, the content of the above-mentioned antioxidant may be about 1-30 parts by weight, preferably about 1-10 parts by weight. Within the above-mentioned range, the above-mentioned transmittance and adhesion improvement of the insulating film can be effectively achieved.

Photoacid generator (C)

The photosensitive composition of an exemplary embodiment may be a CAR-type composition including a photoacid generator.

The above-mentioned photoacid generator is a compound that generates an acid (for example, proton (H ⁺ )) through an exposure process using ultraviolet rays or radiation, and a known compound in the field of photosensitive compositions can be used without particular limitation.

For example, the above-mentioned photoacid generators may include diazonium salts, phosphonium salts, peronium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazobisphosphonates, diazoniums , Ortho-nitrobenzyl sulfonate, triazine compounds, etc. These can be used alone or in combination of two or more.

The content of the photoacid generator can be, for example, about 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of the above-mentioned binder resin. Within the above range, sufficient sensitivity to the exposure process can be obtained without hindering the transmittance and mechanical properties through the binder resin and the antioxidant.

In some embodiments, in order to improve the sensitivity of the exposure process, a sensitizer may be used together with the above-mentioned photoacid generator. For example, the acid generation from the above-mentioned photoacid generator can be increased by the above-mentioned sensitizer.

For example, the above-mentioned sensitizers may include polynuclear aromatics, xanthenes, xanthones, cyanines, oxonols, thiazines, acridines, acridines, anthraquinones, squaliums , styryl, base styryl, coumarin, anthracene, etc. They may be used alone or in combination of two or more.

In one embodiment, the above-mentioned sensitizer may include a compound represented by the following chemical formula 6.

[Chemical formula 6]

In Chemical Formula 6, L ₁ and L ₂ independently of each other may be an alkyl group having 1 to 6 carbon atoms.

For example, the above-mentioned sensitizer may include at least one of the compounds represented by the following chemical formulae 6-1 to 6-3.

[Chemical formula 6-1]

[Chemical formula 6-2]

[Chemical formula 6-3]

For example, with respect to 100 parts by weight of the above-mentioned binder resin, the content of the sensitizer may be about 0.01 to 60 parts by weight, preferably about 0.5 to 10 parts by weight. Within the above range, for example, the effect of improving the transmittance through the above-mentioned antioxidant is not hindered, and the sensitivity to the exposure process can be improved.

solvent

The said photosensitive composition can use the organic solvent which has sufficient solubility with respect to organic components, such as the said binder resin and antioxidant, as a solvent.

For example, ether-based, acetate-based, ester-based, ketone-based, amide-based, and lactone-based solvents may be used, and these may be used alone or in combination of two or more.

Examples of ether-based solvents include ethylene glycol monoalkyl ether, ethylene glycol dialkyl ether, propylene glycol monoalkyl ether, propylene glycol dialkyl ether, diethylene glycol dialkyl ether, and dipropylene glycol monoalkyl ether. Alkyl ether, dipropylene glycol dialkyl ether, diethylene glycol methyl ethyl ether, etc.

Examples of acetate-based solvents include ethylene glycol monomethyl ether acetate, ethylene glycol monoalkyl ether acetate, propylene glycol monoalkyl ether acetate, and diethylene glycol monoalkyl ether. Acetate, dipropylene glycol monoalkyl ether acetate, propylene glycol dialkyl ether acetate, etc.

Examples of ester-based solvents include ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethoxyacetate Ethyl acetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 3-methoxypropionate Butyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl Butyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate, etc.

Examples of ketone-based solvents include methyl ethyl ketone, methyl propyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, 2-heptanone, 3-heptanone, and 4-heptanone ketone, cyclohexanone, etc.

Examples of the amide-based solvent include N-methylformamide, N,N-dimethylformamide, N-methylacetamide, N,N-dimethylacetamide, N,N-dimethylacetamide, and N,N-dimethylacetamide. - Methylpyrrolidone, etc. As an example of the lactone-based solvent, γ-butyrolactone is mentioned.

Preferably, in terms of coatability and thickness uniformity of the insulating film, propylene glycol methyl ether acetate, diethylene glycol methyl ethyl ether, or a mixture thereof can be used.

Content of the said solvent may be the remainder other than the said component and the additive mentioned later. For example, in the total weight of the photosensitive composition, the content of the solvent may be about 40 to 90% by weight, preferably about 50 to 80% by weight. Within the above range, the content and viscosity of the solid content can be appropriately maintained, and the coatability of the composition can be improved.

additive

For example, the above-mentioned photosensitive composition may further include an additive within a range not to impair the interaction of the above-mentioned binder resin, linear vinyl ether compound, and photoacid generator.

The above-mentioned additives can include basic compounds, surfactants, coupling agents, thermal crosslinking agents, light stabilizers, photocuring accelerators, leveling agents, defoaming agents, etc., and compounds commonly used in the field of photosensitive compositions can be used .

For example, the above-mentioned basic compound may be included for adjusting developability, and may include aliphatic amines, aromatic amines, heterocyclic amines, quaternary ammonium hydroxide, quaternary ammonium salts of carboxylic acids, and the like.

The said surfactant can improve the adhesiveness of a base material and a photosensitive composition.

The above-mentioned surfactants may include fluorine-based surfactants, nonionic surfactants, cationic surfactants, anionic surfactants, organosilicon-based surfactants, and the like, which are widely known in the art. These may be used alone or in combination of two or more.

The said coupling agent can be included in order to improve the adhesiveness of the said photosensitive composition and the board|substrate containing an inorganic substance, and to adjust the taper angle of an insulating pattern.

The above-mentioned coupling agent may include, for example, a silane coupling agent or a thiol-based compound, and preferably, a silane coupling agent may be used.

Examples of the above-mentioned silane coupling agent include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrialkoxysilane, γ-ring Oxypropoxypropyl alkyl dialkoxysilane, γ-methacryloyloxypropyl trialkoxysilane, γ-methacryloyloxypropyl alkyl dialkoxysilane, γ-chloropropyl Trialkoxysilane, γ-mercaptopropyltrialkoxysilane, β-(3,4-epoxycyclohexyl)ethyltrialkoxysilane, vinyltrialkoxysilane, etc.

The thermal crosslinking agent as the composition can further improve the crosslinking degree of the insulating film through post-baking and other heat treatment processes, thereby improving the hardness and heat resistance.

The above-mentioned thermal crosslinking agent may include, for example, polyacrylate resins, epoxy resins, phenolic resins, melamine resins, organic acids, amine compounds, anhydrous compounds, and the like.

The said light stabilizer can improve the light resistance of the said photosensitive composition. The above-mentioned light stabilizer may include, for example, benzotriazole-based, triazine-based, benzophenone-based, hindered aminoether-based, hindered amine-based compounds, and the like.

The content of the above-mentioned additives can be appropriately changed in consideration of the process conditions, for example, relative to 100 parts by weight of the binder resin, it can be included in a content of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight.

<Insulating film and image display device>

Embodiments of the present invention provide an insulating film formed from the above-mentioned photosensitive composition and a method for producing the same.

FIGS. 1 to 5 are schematic cross-sectional views for explaining an insulating film forming method of an exemplary embodiment.

Referring to FIG. 1 , a first conductive pattern 110 may be formed on the substrate 100 .

The substrate 100 may be, for example, a glass substrate or a resin substrate including polyimide, polymethyl methacrylate (PMMA), and the like. For example, the substrate 100 may be a display panel substrate of an image display device.

The first conductive pattern 110 can be formed by evaporating metal or a transparent conductive oxide such as ITO to form a first conductive film and then etching the first conductive film.

In some embodiments, before forming the first conductive pattern 110 , a barrier film including silicon oxide, silicon nitride, silicon oxynitride, etc. may be formed on the upper surface of the substrate 100 .

The first conductive pattern 110 may be provided, for example, as an electrode such as a gate electrode, a source electrode, or a drain electrode of a thin film transistor (TFT) included in an image display device. In some embodiments, the first conductive pattern 110 may also be provided as wirings such as scan lines, data lines, and power lines of the image display device.

Referring to FIG. 2 , a pre-insulation film 120 covering the first conductive pattern 110 may be formed on the substrate 100 . The pre-insulation film 120 can be formed by applying the above-mentioned photosensitive composition by spin coating, slot coating, or roll coating process, and then performing drying and/or soft baking process. For example, the above-mentioned soft-baking process can be performed in a temperature range of about 60-150°C.

As described above, since the photosensitive composition includes a bifunctional epoxy compound as an antioxidant, the fluidity of the composition is enhanced, and the film flatness and coatability can be further improved. In addition, the adhesion to the substrate 100 can be further enhanced by the combination of the first resin to the third resin described above.

Referring to FIG. 3 , through an exposure process, the pre-insulating film 120 can be transformed into an insulating film including an exposed portion 123 and a non-exposed portion 125 .

According to an exemplary embodiment, after disposing a photomask including a light shielding portion and a transmission portion on the pre-insulating film 120, excimer laser, far-ultraviolet, ultraviolet, visible light, electron beam, X-ray or g radiation can be irradiated through the above-mentioned photomask. -Line (wavelength 436nm), i-line (wavelength 365nm), h-line (wavelength 405nm), etc. light.

For example, the transmissive portion of the mask may overlap with the first conductive pattern 110 , and the portion of the pre-insulation film 120 irradiated with light through the transmissive portion may be converted into the exposure portion 123 .

According to an exemplary embodiment, through the above-mentioned exposure process, acid is generated from the photoacid generator included in the above-mentioned photosensitive composition to enable the acid-decomposable group included in the binder resin (eg, the first resin) break away. Thereby, the hydroxyl group of the phenol unit protected by the said acid-decomposable group is exposed, and the solubility with respect to the developing solution of the exposure part 123 can be increased.

In some embodiments, in order to prevent the diffusion of the acid generated after the exposure process, a post exposure bake (Post Exposure Baking: PEB) process may also be performed.

Referring to FIG. 4 , the exposed portion 123 may be removed by performing a development process. Thus, the insulating pattern can be defined by the remaining non-exposed portion 125 . The development process described above can be implemented using an alkaline developer such as tetramethylammonium hydroxide (TMAH).

In the space where the exposure portion 123 is removed by the above-described development process, for example, an opening portion 127 that exposes at least a part of the first conductive pattern 110 may be formed.

In an exemplary embodiment, after the above-described development process, in order to improve mechanical properties through further curing of the insulating pattern (eg, the remaining non-exposed portions 125 ), a post-baking process may be further performed. The above post-baking process can be performed at a temperature of about 150 to 350°C.

In the case of performing high-temperature heat treatment such as the above-mentioned post-baking process, the phenol units included in the above-mentioned binder resin may be oxidized (eg, become quinone units), resulting in yellowing of the above-mentioned insulating pattern.

However, according to an exemplary embodiment, the above-mentioned phenol unit can be protected by the above-mentioned difunctional epoxy-based compound to suppress yellowing, thereby maintaining the transmittance of the above-mentioned insulating pattern.

Referring to FIG. 5 , the second conductive pattern 130 may be formed in the opening 127 shown in FIG. 4 .

For example, the second conductive pattern 130 may be formed by fully filling the opening portion 127 and forming a second conductive film including a metal or a transparent conductive oxide on the non-exposed portion 125 , and then patterning the second conductive film.

Even when a heat treatment process such as a high-temperature vapor deposition process is performed to form the second conductive film, yellowing and peeling of the non-exposed portion 125 can be suppressed by the action of the above-described bifunctional epoxy compound.

The second conductive pattern 130 may be provided, for example, as a picture element electrode of an image display device, or may be provided as various wiring structures. For example, in order to be electrically connected to the first conductive pattern 110, the second conductive pattern 130 may be provided as a picture element electrode including a via structure penetrating the above-mentioned insulating pattern. In this case, the first conductive pattern 110 may be provided as a drain electrode connected to the above-mentioned picture element electrode.

Embodiments of the present invention provide an image display device including the above-described insulating film or insulating pattern. The above-mentioned insulating film can be provided as a gate insulating film, an interlayer insulating film, a via insulating film, or the like of the above-mentioned image display device. For example, the second conductive pattern 130 shown in FIG. 5 is provided as a picture element electrode, and a display layer including a liquid crystal layer or an organic light-emitting layer is formed on the second conductive pattern 130, so that an LCD device, an OLED device, or the like can be formed.

A counter electrode (eg, a cathode) opposing the picture element electrode may be arranged on the display layer, and additional structures such as an encapsulant layer, a hard coat layer, and a window substrate may be stacked on the counter electrode.

As described above, since the insulating film suppresses the yellowing phenomenon caused by the heat treatment and has excellent transparency, the image quality of the image display device can be improved.

Below, in order to help the understanding of the present invention, preferred embodiments are provided, but these embodiments are only illustrative of the present invention, and do not limit the scope of the accompanying patent application. It is obvious to those skilled in the art that within the scope of the present invention and Various changes and modifications can be made to the embodiments within the scope of technical ideas, and of course such changes and modifications also belong to the scope of the accompanying patent application.

Examples and Comparative Examples

A positive-type photosensitive resin composition having the composition and content (parts by weight) described in Table 1 below was produced.

[Table 1]

The specific ingredients are as follows. The numerical value of each unit included in the binder resin (A) represents mol%.

A1-1, A1-2

A1-1) p/q=60/40, Mw=12,000

A1-2)p/q=70/30, Mw=12,000

A2-1, A2-2

A2-1)(a)/(b)/(c)=60/20/20, Mw=8,000

A2-2)(a)/(b)/(c)=60/10/30, Mw=8,000

A3-1, A3-2

A3-1: (a)/(b)/(c)/(d)=15/10/50/25, Mw=25,000

A3-2: (a)/(b)/(c)/(d)=25/15/30/30, Mw=25,000

(ED-523T，Adeka公司製造) B-1)

(ED-523T, manufactured by Adeka Corporation)

(Epolight 100MF，共榮社公 司製造) B-2)

(Epolight 100MF, manufactured by Kyoeisha Corporation)

(S-400，新納希公司製造)B-3)

(S-400, manufactured by Sinash Corporation)

C-1)

C-2)

D1) Propylene Glycol Methyl Ether Acetate

D2) Diethylene glycol methyl ethyl ether

F) γ-glycidoxypropyl trialkoxysilane

G) SH-8400 (Dow Corning)

Experimental example

The following evaluation was performed about the photosensitive composition manufactured based on the Example and the comparative example of Table 1, and the result is described in the following Table 2.

(1) Sensitivity measurement

On a glass substrate (Corning 1737, manufactured by Corning Incorporated) having a thickness of 0.7 mm, the photosensitive resin compositions of Examples and Comparative Examples were respectively coated with a spin coater, and heated on a hot plate at 100° C. for 125 seconds to make the photosensitive resin compositions. The solvent evaporates to form a pre-insulation layer with a thickness of 4.0 μm.

Then, in order to obtain a contact hole pattern with a diameter of 10㎛, exposure was performed through an i-line stepper (NSR-205i11D, Nikon Co., Ltd.) using a mask having a quadrangular pattern opening with an exposure portion having a side of 10 μm.

The exposed substrate was developed with 2.38% tetramethylammonium hydroxide aqueous solution as a developer at 23°C for 40 seconds by spin-over immersion development, and heated in an oven at 230°C for 30 minutes to form a cured insulating pattern.

Then, the substrate was vertically cut, the exposure amount required to form a 10㎛ contact hole in each insulating pattern was measured, and the sensitivity was evaluated.

(2) Film retention rate

The photosensitive resin compositions produced in Examples and Comparative Examples were coated on a glass substrate (Corning 1737, manufactured by Corning Incorporated) with a thickness of 0.7 mm using a spin coater, and the solvent was volatilized by heating on a hot plate at 100° C. for 125 seconds. , and then the film thickness (A) was measured. After that, spin-over immersion development was performed at 23°C for 40 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution as a developer, heated in an oven at 230°C for 30 seconds to form an insulating pattern, and the film thickness (B) was measured as follows. The film retention rate was calculated by the above-mentioned formula 1.

[Mathematical formula 1]

Film retention rate (%) = B / A * 100

(3) Pattern angle

In order to measure the sensitivity, the formed insulating pattern was cut vertically, and the angle with the substrate was calculated from the optical photograph.

(4) Adhesion

On the glass substrate on which the silicon nitride film (SiNx) was vapor-deposited, the photosensitive compositions of Examples and Comparative Examples were directly coated with a spin coater, and heated on a hot plate at 100° C. for 125 seconds to volatilize the solvent. Pre-insulation film with a thickness of 4.0 μm. Then, exposure was performed with an i-line stepper (NSR-205i11D, Nikon Co., Ltd.) using a photomask including a hole pattern in the range of 5-20 μm. The exposed substrate was subjected to spin immersion development at 23° C. for 40 seconds using a 2.38% tetramethylammonium hydroxide aqueous solution as a developer, and the peeling of the pattern was confirmed. The evaluation criteria are as follows.

⊚: The pattern is not peeled off at all in the entire area

○: The pattern is slightly peeled off in some areas

△: Most of the patterns are peeled off

X: The pattern is peeled off in all areas

(5) Penetration measurement

In order to measure the sensitivity measurement, about the formed insulating pattern, the transmittance at 400 nm was measured with a spectrophotometer.

(6) Penetration rate after additional baking

After the transmittance measurement was performed as shown in (5), additional baking was performed at 230° C. in an oven for 30 minutes, and the transmittance at 400 nm was measured again with a spectrophotometer.

[Table 2]

Referring to Table 2, the examples including both the binder resin and the bifunctional epoxy-based compound as an antioxidant exhibited excellent sensitivity and pattern characteristics as a whole compared with the comparative examples, and also ensured excellent results after additional baking. penetration rate. In the case of Example 13 in which the amount of antioxidant was decreased, the penetration rate after additional baking was slightly decreased. In the case of Example 14 in which the antioxidant amount was increased, the pattern adhesiveness deteriorated.

In the case of Comparative Example 1 in which the antioxidant was absent, the sensitivity decreased, and the transmittance was also significantly deteriorated after the baking process. Comparative Examples 2 and 3 including the trifunctional or tetrafunctional epoxy-based compound also failed to achieve the desired penetration rate improvement effect due to steric hindrance within the antioxidant.

100‧‧‧Substrate 110‧‧‧First conductive pattern 120‧‧‧Pre-insulation film 123‧‧‧Exposed part 125‧‧‧ Non-exposed part 127‧‧‧Opening part 130‧‧‧Second conductive pattern

FIGS. 1 to 5 are schematic cross-sectional views illustrating a method of forming an insulating film according to an exemplary embodiment.

100‧‧‧Substrate

110‧‧‧First Conductive Pattern

123‧‧‧Exposure Department

125‧‧‧Non-Exposure Section

Claims (10)

A positive photosensitive resin composition, comprising: a binder resin; an antioxidant containing a difunctional epoxy compound; a photoacid generator; and a solvent; wherein the binder resin comprises a first resin, the The first resin includes a phenol unit protected by an acid-decomposable group; wherein the binder resin further includes at least one of a second resin and a third resin, the second resin includes an epoxy group-containing acrylic resin, The third resin includes an oxetane group-containing acrylic resin; wherein the total 100 parts by weight of the binder resin includes 30-55 parts by weight of the first resin, 30-60 parts by weight of the second resin and the 1 to 25 parts by weight of the third resin; wherein in the total weight of the positive photosensitive resin composition, the content of the binder resin is 5 to 50% by weight, and in 100 parts by weight of the binder resin, the antioxidant The content of 1 to 10 parts by weight; wherein the antioxidant comprises the monomer represented by the following chemical formula 5,

In Chemical Formula 5, R ¹ is an alkylene group having 1 to 6 carbon atoms or a cycloalkylene group having 3 to 12 carbon atoms. The positive-type photosensitive resin composition according to claim 1, wherein the first resin comprises a structural unit represented by the following chemical formula 1, and chemical formula 1

In Chemical Formula 1, R ₁ and R ₂ are each independently hydrogen or methyl, and R ₃ represents the acid-decomposable group, which is substituted or unsubstituted with an alkyl group having 1 to 6 carbon atoms. ~10 alkyl group, tetrahydropyranyl group, or C1~10 alkyl group substituted or unsubstituted with alkoxy group with 1~6 carbon atoms or cycloalkoxy group with 4~8 carbon atoms , p is 40~80 mol%, and q is 20~60 mol%. The positive-type photosensitive resin composition according to item 2 of the claimed scope, wherein the first resin comprises a structural unit represented by the following chemical formula 1-1,

In Chemical Formula 1-1, R ₁ and R ₂ are each independently hydrogen or methyl, R ₄ and R ₅ are each independently an alkyl group having 1 to 6 carbon atoms, p is 40 to 80 mol%, and q is 20~60 mol%. The positive-type photosensitive resin composition according to claim 1, wherein the second resin is derived from at least one of the monomers represented by the following chemical formula 2 and chemical formula 3, and chemical formula 2

In Chemical Formulas 2 and 3, Z ₁ is hydrogen or a methyl group, Z ₂ is an alkylene group having 1 to 6 carbon atoms, Z ₃ and Z ₄ are independently hydrogen or an alkyl group having 1 to 6 carbon atoms, or They are connected to each other to form a ring having 3 to 8 carbon atoms, and m is an integer of 1 to 6. The positive-type photosensitive resin composition according to claim 1, wherein the third resin includes a structural unit derived from a monomer represented by the following chemical formula 4,

In Chemical Formula 4, Ra is hydrogen or a methyl group, Rb is an alkylene group having 1 to 6 carbon atoms, and Rc is an alkyl group having 1 to 6 carbon atoms. The positive-type photosensitive resin composition according to item 1 of the claimed scope, wherein the antioxidant comprises a compound represented by the following chemical formula 5-1,

The positive-type photosensitive resin composition according to the claim 1, wherein the photoacid generator is selected from the group consisting of diazonium salts, phosphonium salts, periconium salts, iodonium salts, and imide sulfonates At least one selected from the group consisting of compounds, oxime sulfonate, diazobis, diazo, o-nitrobenzyl sulfonate and triazine. An insulating film formed from the positive photosensitive resin composition according to any one of claims 1 to 7. The insulating film according to claim 8, which is used as an interlayer insulating film or a through-hole insulating film of an image display device. An image display device including the insulating film as described in claim 8 of the scope of application.

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