TW202039603A - Resin composition and method for manufacturing substrate including microlens pattern - Google Patents

Abstract

To provide a resin composition to be used for forming a dot pattern in a process of forming a microlens pattern by heating the dot pattern comprising rectangular dots and a lattice-like space to induce a thermal flow of the dot pattern, the composition capable of forming a dot pattern that can thermally flow even at a low temperature, and a method for manufacturing a substrate including a microlens pattern using the above resin composition. The resin composition is to be used for forming a dot pattern in a process of forming a microlens pattern by heating the dot pattern comprising rectangular dots and a lattice-like space to induce a thermal flow of the dot pattern. A resin film formed by using the resin composition has a glass transition temperature Tg of 70 DEG C or lower measured under predetermined conditions.

Description

Resin composition and method for manufacturing substrate with microlens pattern

The invention provides a resin composition and a method for manufacturing a microlens pattern using the resin composition.

At present, digital cameras and mobile phones with cameras that are widely used are equipped with solid-state imaging elements. As a representative solid-state imaging element, a CCD (charge coupled device) image sensor or a CMOS (complementary metal-oxide semiconductor) image sensor can be cited. In these image sensors, fine lenses (hereinafter referred to as micro lenses) are provided for the purpose of improving sensitivity. In the manufacturing of the image sensor, in addition to the microlens, other parts such as color filters are formed as needed.

In recent years, the miniaturization of solid-state imaging devices and the increase in the number of imaging pixels have advanced, and various researches and developments have been carried out in order to improve the light collection efficiency. For example, Patent Document 1 proposes to coat a photoresist film on a flattened layer formed on the upper side of the light-receiving part of a solid-state imaging element, and after exposing the photoresist film through a photomask, the exposed photoresist film is developed to make The method of patterning photoresist film into lens shape. In the method described in Patent Document 1, the photoresist film is exposed using a photomask formed with a light-transmitting portion composed of a medium of a light refraction system having a stepped portion on the surface. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2003-98649 A

[Problem to be solved by the invention]

On the other hand, after the precursor pattern of the microlens pattern formed of the resin composition is formed, by heat-treating the precursor pattern to flow heat, the microlens pattern can also be formed. In the method described in Patent Document 1, it is necessary to use a mask with a precisely designed shape. Such masks are expensive and difficult to manufacture. However, if the above-mentioned heat flow method is used, it is not necessary to use the photomask as described in Patent Document 1.

Regarding the above-mentioned method of manufacturing microlens patterns by heat flow, from the viewpoint of the heat resistance of the materials used in solid-state imaging devices or the reduction of the manufacturing energy of the microlens patterns, it is required that even if the heating temperature is lowered, good formation can be achieved. A resin composition with a thermally flowing pattern.

The present invention was accomplished in view of the above-mentioned problems, and its object is to provide a resin composition and a method for manufacturing a substrate with a microlens pattern using the resin composition, the resin composition being formed by combining rectangular dots and grid When the dot pattern heating formed by the interval of the dot pattern heats the dot pattern to form a micro lens pattern, it is used to form a dot pattern, and it can form a dot pattern that can flow well even at low temperatures. [Means to solve the problem]

The inventors discovered that when a dot pattern formed by rectangular dots and grid-like spaces is heated, the dot pattern heat flows to form a microlens pattern, it is used to form a dot pattern resin composition Among them, by setting the glass transition temperature Tg measured under specific conditions of the resin film formed using the resin composition to 70°C or less, the above-mentioned problems can be solved, and the present invention has finally been completed. More specifically, the present invention provides the following.

The first aspect of the present invention is a resin composition, which is based on heating a dot pattern formed by rectangular dots and grid-like spaces (space) to make the dot pattern heat flow. In the method of forming the pattern, the resin composition used to form the aforementioned dot pattern, The resin composition contains resin (A), The resin film formed by using the resin composition has a glass transition temperature Tg of 70°C or less as measured by a method including the following steps (1) to (4); (1) The step of spin coating the resin composition on the substrate to form a coating film, (2) The step of heating the coating film at 100°C for 90 seconds to form a resin film, (3) Collect a sample for glass transition point measurement from the obtained resin film, and use the obtained sample to perform a differential scanning calorimeter (DSC) measurement to obtain a reversing heat flow curve, and (4) The step of reading the minimum value in the differential curve derived from the first derivative of the obtained reverse heat flow curve with the temperature as the glass transition temperature Tg, and determining the value of the glass transition temperature Tg.

The second aspect of the present invention is a method for manufacturing a substrate with a microlens pattern, which includes: Using the resin composition of the first aspect, a step of forming a dot pattern consisting of rectangular dots and grid-like spaces on a substrate, and The heat flow step of making the heat flow through the heating point pattern. [Effects of the invention]

According to the present invention, it is possible to provide a resin composition and a method for manufacturing a substrate with a microlens pattern using the resin composition, the resin composition being a dot pattern formed by rectangular dots and grid-like spaces It is used to form a dot pattern when the dot pattern heat flows to form a micro lens pattern, and it can form a dot pattern that can flow heat well even at low temperatures.

[The form of implementing the invention] ≪Resin composition≫

The resin composition is used to form a dot pattern in a method of heating a dot pattern formed by rectangular dots and grid-like spaces to flow the dot pattern heat to form a micro lens pattern to form a micro lens pattern. type. Here, the microlens pattern is a pattern formed by two or more microlenses each arranged at a designated position.

The resin composition contains resin (A). In addition, the glass transition temperature Tg of the resin film formed using the resin composition, measured in accordance with the method including the steps (1) to (4) below, is 70°C or less. The value of this Tg is more preferably 68°C or less, particularly preferably 66°C or less. (1) The step of spin-coating the resin composition on the substrate to form a coating film, (2) The step of heating the coating film at 100°C for 90 seconds to form a resin film, (3) Collect a sample for glass transition point measurement from the obtained resin film, and use the obtained sample to perform a differential scanning calorimeter (DSC) measurement to obtain a reversing heat flow curve, and (4) The step of reading the minimum value in the differential curve derived from the first derivative of the reverse heat flow curve with the temperature as the glass transition temperature Tg, and determining the value of the glass transition temperature Tg. In addition, the lower limit of Tg is preferably 40°C or higher, more preferably 50°C or higher, and particularly preferably 55°C or higher.

Since the resin composition has the above-mentioned thermal characteristics, it is possible to realize good heat flow at low temperatures in a dot pattern formed by the resin composition.

The Tg measured by the above method can be adjusted by, for example, appropriately changing the chemical structure of the structural unit constituting the resin (A). In addition, when the resin (A) contains two or more types of structural units, the Tg measured by the above method can be adjusted by changing the ratio of the structural units. Furthermore, when the resin composition contains a photosensitive agent (B) as described later, the Tg measured by the above method can be adjusted by changing the type or content of the photosensitive agent (B) contained in the resin composition.

The method of forming the dot pattern is not particularly limited. For example, the dot pattern can be formed by a printing method such as an inkjet printing method. The dot pattern can also be formed by a lithography method including patterning of exposure and development.

As the resin composition, a photosensitive resin composition capable of forming a dot pattern by a photolithography method is preferable in terms of easily forming a fine and good-shaped dot pattern.

Regarding the dot pattern formed using the resin composition, the width of the space is preferably 0.2 μm or more and 2.0 μm or less, and more preferably 0.25 μm or more and 1.0 μm or less. In addition, when the width of the space is W and the height of the dot is H, the aspect ratio indicated by H/W is preferably 1.0 or more and 10.0 or less, and more preferably 2.0 or more and 8.0 or less. The height H of the dot is not particularly limited, but it is typically preferably 0.25 μm or more and 4.0 μm or less, and more preferably 0.5 μm or more and 2.0 μm or less. Also, the dot pattern is formed on the substrate. Each point constituting the dot pattern is usually a rectangular parallelepiped shape, a cube shape, or a shape similar to these shapes, and the size of the dot in the same direction as the thickness direction of the substrate is regarded as the height H of the dot.

In addition, the shape of the rectangular surface of the dot in the same direction or substantially the same direction as the surface direction of the substrate is a square, a rectangle, or a shape similar to these shapes. Regarding the rectangular surface of the dot in the same direction or substantially the same direction as the surface direction of the substrate, the length of each of the four sides is preferably 0.5 μm or more and 5 μm or less, more preferably 1 μm or more and 4 μm or less.

Regarding the dot pattern formed by using the resin composition, if the width and aspect ratio of the gap are within the above-mentioned range, it is easy to obtain a microlens pattern of a desired shape after heat flows.

In addition, the temperature of the heat flow of the dot pattern formed using the resin composition is preferably (Tg+5)°C or higher and 130°C or lower, and more preferably (Tg+5)°C or higher and 100°C or lower. Due to the temperature within this range, when the dot pattern heat flow formed by the resin composition is used, it is easy to make the dot pattern heat flow to the desired degree while suppressing the excessive heat flow of the dot pattern.

As a preferable resin composition, the photosensitive resin composition containing alkali-soluble resin (A1) as resin (A) and the photosensitive agent (B) is mentioned. Hereinafter, the necessary or optional components contained in the preferable photosensitive resin composition will be described.

＜Alkali-soluble resin (A1)＞ The alkali-soluble resin (A1) is not particularly limited as long as it is a resin having an alkali-soluble group such as a carboxyl group and a phenolic hydroxyl group and is soluble in an alkaline solution. For example, as the alkali-soluble resin (A1), phenol resins, acrylic resins, copolymers of styrene and acrylic acid, polymers or copolymers of hydroxystyrene, polyvinylphenol, polyα-methylvinyl Phenol, etc.

(式(a1)中，R¹ 表示氫原子或甲基，R² 表示單鍵或碳原子數1以上5以下的伸烷基，R³ 表示碳原子數1以上5以下的烷基，a表示1以上5以下之整數，b表示0以上4以下之整數，a+b為5以下，b為2以上時，複數的R³ 可互相相同，也可相異)。The alkali-soluble resin (A1) preferably contains a (meth)acrylic resin containing a structural unit represented by the following formula (a1),

(In formula (a1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond or an alkylene group having 1 to 5 carbon atoms, R ³ represents an alkyl group having 1 to 5 carbon atoms, and a represents An integer of 1 or more and 5 or less, b represents an integer of 0 or more and 4 or less, a+b is 5 or less, and when b is 2 or more, the plural R ³ may be the same or different).

When the (meth)acrylic resin contains the structural unit represented by the above formula (a1), it is easy to obtain good patterning characteristics when the photosensitive resin composition is used to form a dot pattern.

In the above formula (a1), when R ² is an alkylene group having 1 to 5 carbon atoms, the alkylene group may be linear or branched. Specific examples of the alkylene group of R ² include methylene, ethane-1,2-diyl, ethane-1,1-diyl, propane-1,3-diyl, and propane-1 ,2-diyl, propane-1,1-diyl, propane-2,2-diyl, butane-1,4-diyl, butane-1,3-diyl, butane-1,2 -Diyl, butane-1,1-diyl, butane-2,3-diyl, butane-2,2-diyl, pentane-1,5-diyl, pentane-1,4 -Diyl, pentane-1,3-diyl, pentane-1,2-diyl, pentane-1,1-diyl, pentane-2,4-diyl, pentane-2,3 -Diyl, pentane-2,2-diyl and pentane-3,3-diyl.

As R ² explained above, it is easy to obtain or synthesize a compound that can be given to the structural unit represented by formula (a1), or from the use of a resin composition, it is easy to form a dot pattern that can flow at low temperatures. From a point of view, a single bond, a methylene group, and an ethane-1,2-diyl group are preferred, a single bond and a methylene group are more preferred, and a single bond is particularly preferred.

In the above formula (a1), R ³ is an alkylene group having 1 to 5 carbon atoms. The alkylene group of R ³ may be linear or branched. Specific examples of the alkylene group of R ³ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, second butyl, tertiary butyl, n-pentyl, Isopentyl, neopentyl, second pentyl, third pentyl and pentane-3-yl.

In formula (a1), a of the number of hydroxyl groups on the benzene ring is an integer of 1 or more and 5 or less. As a, 1 or 2 is preferable, and 1 is more preferable from a viewpoint of easy acquisition or synthesis of the compound which can give the structural unit represented by formula (a1).

In formula (a1), at least one of the one or more hydroxyl groups is on the benzene ring, and is preferably bonded to the para position relative to the position where the group represented by -CO-OR ² -is bonded .

As the structural unit represented by the formula (a1), for example, a structural unit represented by the following formula (a1-1) or the following formula (a1-2) is preferable. In formula (a1-1) and formula (a1-2), R ¹ is a hydrogen atom or a methyl group.

In the (meth)acrylic resin containing the structural unit represented by the formula (a1), the content of the structural unit represented by the formula (a1) is preferably 20% by mass or more and 80% by mass or less, more preferably 20% by mass Above 70% by mass, particularly preferably 20% by mass to 60% by mass, and particularly preferably 20% by mass to 50% by mass. In the (meth)acrylic resin containing the structural unit represented by the formula (a1), the lower limit of the content of the structural unit represented by the formula (a1) is also preferably 25% by mass or more or 30% by mass or more. In the (meth)acrylic resin containing the structural unit represented by the formula (a1), if the content of the structural unit represented by the formula (a1) is within the above-mentioned range, it is easy to simultaneously form dots using the photosensitive resin composition Good patterning characteristics when patterning and good low-temperature thermal fluidity of dot patterning.

The (meth)acrylic resin containing the structural unit represented by the above formula (a1) preferably further contains 1 or more carbon atoms derived from (meth)acrylic acid together with the structural unit represented by the above formula (a1) The structural unit of alkyl ester of 10 or less. In this case, a photosensitive resin composition can be used, and it is particularly easy to form a dot pattern with excellent low-temperature thermal fluidity.

The alkyl ester of (meth)acrylic acid having 1 to 10 carbon atoms is preferably an alkyl ester of (meth)acrylic acid having 2 to 6 carbon atoms, and more preferably (meth)acrylic acid. 3 to 5 alkyl esters. The alkyl system constituting the alkyl ester may be linear or branched, and is preferably linear.

Preferable specific examples of the alkyl ester of (meth)acrylic acid include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate Ester, n-butyl (meth)acrylate, isobutyl (meth)acrylate, second butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, (meth) ) N-heptyl acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate and n-decyl (meth)acrylate. Among these, ethyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and n-pentyl (meth)acrylate are preferred. Esters and n-hexyl (meth)acrylate.

In the (meth)acrylic resin containing the structural unit represented by formula (a1), the content of the structural unit of the alkyl ester having 1 to 10 carbon atoms derived from (meth)acrylic acid is preferably 10% by mass or more 80% by mass or less, more preferably 15% by mass or more and 80% by mass or less, and particularly preferably 20% by mass or more and 80% by mass or less.

The (meth)acrylic resin containing the structural unit represented by the formula (a1) may also contain the structural unit represented by the formula (a1) and derived from (meth)acrylic acid within a range that does not hinder the purpose of the present invention. A structural unit other than the structural unit of the alkyl ester having 1 to 10 carbon atoms. Examples of monomers that give this other structural unit include (meth)acrylic acid esters and epoxy-containing (meth)acrylic acid esters other than alkyl esters having 1 to 10 carbon atoms. Unsaturated compounds, (meth)acrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, etc. These compounds can be used alone or in combination of two or more kinds.

Examples of (meth)acrylates having no epoxy group include chloroethyl (meth)acrylate, 2,2-dimethylhydroxypropyl (meth)acrylate, and 2-(meth)acrylate Hydroxyethyl, trimethylolpropane mono(meth)acrylate, (meth)acrylic acid benzoate, and (meth)acrylate furfuryl, etc.

Examples of the unsaturated compound having an epoxy group include glycidyl (meth)acrylate, 2-methylglycidyl (meth)acrylate, and 3,4-epoxybutyl (meth)acrylate. Ester, 6,7-epoxyheptyl (meth)acrylate and other epoxy alkyl (meth)acrylates: α-ethyl glycidyl acrylate, α-n-propyl glycidyl acrylate , Α-n-butyl glycidyl acrylate, α-ethyl acrylate 6,7-epoxyheptyl and other α-alkyl acrylate epoxy alkyl esters, etc. As the unsaturated compound having an epoxy group, a (meth)acrylate having an epoxy group-containing alicyclic group is also preferable.

Examples of (meth)acrylamides include (meth)acrylamide, N-alkylacrylamide, N-aryl(meth)acrylamide, N,N-dialkyl(meth)acrylamide, Yl)acrylamide, N,N-aryl(meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide, N-hydroxyethyl-N-methyl(methyl) ) Acrylamide, etc.

Examples of allyl compounds include allyl acetate, allyl hexanoate, allyl octoate, allyl laurate, allyl palmitate, allyl stearate, and allyl benzoate. , Allyl esters such as allyl acetate and allyl lactate; allyloxyethanol, etc.

Examples of vinyl ethers include hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, and ethoxyethyl vinyl ether. , Chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether , Alkyl groups such as dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc. Vinyl ether; vinyl phenyl ether, vinyl tolyl ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether, vinyl naphthyl ether, vinyl anthracenyl ether, etc. Aryl ether, etc.

Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valerate, vinyl caproate, vinyl chloroacetate, two Vinyl Chloroacetate, Vinyl Methoxy Acetate, Vinyl Butoxy Acetate, Vinyl Phenyl Acetate, Vinyl Acetate, Vinyl Lactate, Vinyl-β-Phenyl Butyrate, Vinyl Benzoate, Vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate, etc.

Examples of styrenes include styrene; methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, Hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxymethylstyrene, acetoxymethylstyrene, etc. Alkylstyrene; Alkoxystyrene such as methoxystyrene, 4-methoxy-3-methylstyrene, dimethoxystyrene, etc.; chlorostyrene, dichlorostyrene, trichlorobenzene Ethylene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4-fluoro -3-Trifluoromethylstyrene and other halogenated styrenes.

In the (meth)acrylic resin containing the structural unit represented by formula (a1), the amount of other structural units is based on the mass of the (meth)acrylic resin, and there is no in the range that does not interfere with the purpose of the present invention The limitation may be the balance after subtracting the mass of the structural unit represented by the formula (a1) and the mass of the structural unit of the alkyl ester having 1 to 10 carbon atoms derived from (meth)acrylic acid.

The content of the (meth)acrylic resin containing the structural unit represented by the above formula (a1) in the alkali-soluble resin (A1) is preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass % Or more, particularly preferably 100% by mass.

The molecular weight of the alkali-soluble resin (A1) is not particularly limited, but is expressed in terms of mass average molecular weight (Mw: measured value in terms of styrene by gel permeation chromatography (GPC)), and is preferably 1,000 or more and 20,000 or less, more Preferably, it is 1500 or more and 15000 or less, particularly preferably 2000 or more and 10,000 or less.

＜Sensitizer (B)＞ The photosensitizer (B) is one that improves the solubility of the photosensitive resin composition in the alkaline developing solution by exposure. The photosensitizer (B) is preferably a quinonediazide group-containing compound.

Examples of the quinonediazide group-containing compound include a complete esterification product or a partial esterification product of a phenol compound and a naphthoquinonediazidesulfonic acid compound. As the above-mentioned phenol compound, for example, polyhydroxy benzophenone compounds such as 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, etc.; tris(4 -Hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,3,5-trimethylphenyl)-2-hydroxy Phenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-4-hydroxyphenylmethane, bis(4-hydroxy-3,5-dimethylphenyl)-3-hydroxyphenyl Methane, bis(4-hydroxy-3,5-dimethylphenyl)-2-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-4-hydroxyphenylmethane, Bis(4-hydroxy-2,5-dimethylphenyl)-3-hydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-2-hydroxyphenylmethane, bis( 4-hydroxy-3,5-dimethylphenyl)-3,4-dihydroxyphenylmethane, bis(4-hydroxy-2,5-dimethylphenyl)-3,4-dihydroxyphenyl Methane, bis(4-hydroxy-2,5-dimethylphenyl)-2,4-dihydroxyphenylmethane, bis(4-hydroxyphenyl)-3-methoxy-4-hydroxyphenylmethane , Bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-4-hydroxyphenylmethane, Bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3-hydroxybenzene Methyl methane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-2-hydroxyphenylmethane, bis(5-cyclohexyl-4-hydroxy-2-methylphenyl)-3, Triphenol-type compounds such as 4-dihydroxyphenylmethane; 2,4-bis(3,5-dimethyl-4-hydroxybenzyl)-5-hydroxyphenol, 2,6-bis(2,5- Linear 3-nuclear phenol compounds such as dimethyl-4-hydroxybenzyl)-4-methylphenol; 1,1-bis[3-(2-hydroxy-5-methylbenzyl)-4-hydroxy- 5-cyclohexylphenyl]isopropane, bis[2,5-dimethyl-3-(4-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane, bis[2,5-di Methyl-3-(4-hydroxybenzyl)-4-hydroxyphenyl]methane, bis[3-(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxy-5-methylbenzene Yl]methane, bis[3-(3,5-dimethyl-4-hydroxybenzyl)-4-hydroxy-5-ethylphenyl]methane, bis[3-(3,5-diethyl- 4-hydroxybenzyl)-4-hydroxy-5-methylphenyl]methane, bis[3-(3,5-diethyl-4-hydroxybenzyl)-4-hydroxy-5-ethylphenyl ]Methane, bis[2-hydroxy-3-(3,5-dimethyl-4-hydroxybenzyl)-5-methylphenyl]methane, bis[2-hydroxy-3-(2-hydroxy-5 -Methylbenzyl)-5-methylphenyl]methane, bis[4-hydroxy-3-(2-hydroxy-5-methylbenzyl)-5-methylphenyl]methane, bis[2, 5-Dimethyl-3-(2-hydroxy-5-methylbenzyl)-4-hydroxyphenyl]methane and other linear 4-nuclear phenol compounds物; 2,4-bis[2-hydroxy-3-(4-hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, 2,4-bis[4-hydroxy-3-(4 -Hydroxybenzyl)-5-methylbenzyl]-6-cyclohexylphenol, 2,6-bis[2,5-dimethyl-3-(2-hydroxy-5-methylbenzyl)-4 -Hydroxybenzyl]-4-methylphenol and other linear polyphenol compounds such as 5-nuclear phenol compounds; bis(2,3,4-trihydroxyphenyl)methane, bis(2,4-dihydroxybenzene) Base) methane, 2,3,4-trihydroxyphenyl-4'-hydroxyphenylmethane, 2-(2,3,4-trihydroxyphenyl)-2-(2',3',4'- Trihydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl)-2-(2',4'-dihydroxyphenyl)propane, 2-(4-hydroxyphenyl)-2-(4 '-Hydroxyphenyl)propane, 2-(3-fluoro-4-hydroxyphenyl)-2-(3'-fluoro-4'-hydroxyphenyl)propane, 2-(2,4-dihydroxyphenyl) )-2-(4'-hydroxyphenyl)propane, 2-(2,3,4-trihydroxyphenyl)-2-(4'-hydroxyphenyl)propane, 2-(2,3,4- Bisphenol-type compounds such as trihydroxyphenyl)-2-(4'-hydroxy-3',5'-dimethylphenyl)propane; 1-[1-(4-hydroxyphenyl)isopropyl] -4-[1,1-bis(4-hydroxyphenyl)ethyl]benzene, 1-[1-(3-methyl-4-hydroxyphenyl)isopropyl]-4-[1,1- Bis(3-methyl-4-hydroxyphenyl)ethyl]benzene and other polynuclear branched compounds; 1,1-bis(4-hydroxyphenyl)cyclohexane and other condensed phenol compounds. These systems can be used in combination of one type or two or more types.

In addition, examples of the naphthoquinone diazide sulfonic acid compound include naphthoquinone-1,2-diazide-5-sulfonyl chloride or naphthoquinone-1,2-diazide-4-sulfonyl chloride Chlorine etc.

In addition, other compounds containing quinonediazide groups can also be used, such as o-benzoquinonediazide, o-naphthoquinonediazide, o-anthraquinonediazide or o-naphthoquinonediazide sulfonates, etc. These nuclear-substituted derivatives, and o-quinone diazide sulfonyl chloride and compounds with hydroxyl or amino groups such as phenol, p-methoxyphenol, dimethylphenol, hydroquinone, bisphenol A, naphthol , Catechol, gallic phenol, gallic phenol monomethyl ether, gallic phenol-1,3-dimethyl ether, gallic acid, esterified or etherified gallic acid, phenol, Reaction products of p-aminodiphenylamine, etc. These systems can be used alone or in combination of two or more types.

Such quinonediazide-containing compounds, for example, can be combined with naphthoquinone-1,2-diazide-5-sulfonyl chloride or naphthoquinone-1,2-diazide 4-sulfonyl chloride is condensed in an appropriate solvent such as dioxane in the presence of bases such as triethanolamine, alkali metal carbonates, alkali metal bicarbonates, etc., to be fully esterified or partially esterified to produce .

Relative to the mass of the resin (A), the amount of the photosensitive agent (B) used is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less. The lower limit of the usage amount of the photosensitive agent (B) is, for example, 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or less with respect to the mass of the resin (A). By using the photosensitizer (B) in such a range, it is possible to easily prepare the above-mentioned resin composition with an appropriate value of Tg. As a result, it is easy to have both good patterning characteristics when the photosensitive resin composition is used to form a dot pattern and good low-temperature thermal fluidity of the dot pattern.

(Other ingredients) The photosensitive resin composition containing the alkali-soluble resin (A1) as the resin (A) and the photosensitizer (B) may contain other components other than the alkali-soluble resin (A1) and the photosensitizer (B) as needed. Examples of other components include organic solvents and thermal crosslinking agents. When the photosensitive resin composition contains a thermal crosslinking agent, the heat resistance of the formed microlens can be improved, and the excessive heat flow of the dot pattern can be easily suppressed.

There are no particular limitations on the thermal crosslinking agent, and for example, the same ones as well-known crosslinking agents can be appropriately selected and used. For example, melamine resin, urea resin, guanamine resin, acetylene urea-formaldehyde resin, succinamide-formaldehyde resin, ethylene urea-formaldehyde resin, etc. can be used. In particular, alkoxymethylated amino resins such as alkoxymethylated melamine resin or alkoxymethylated urea resin can be suitably used. Among them, suitable specific examples of the thermal crosslinking agent include methoxymethylated melamine resin, propoxymethylated melamine resin, butoxymethylated melamine resin, and methoxymethylated urea. Resin, ethoxy methylated urea resin, propoxy methylated urea resin, butoxy methylated urea resin, etc.

The resin composition is prepared by uniformly mixing the components described above.

≪Method for manufacturing substrate with microlens pattern≫ Using the resin composition described above, a substrate with a microlens pattern is produced. Specifically, the method of manufacturing a substrate with a microlens pattern includes: Using the aforementioned resin composition, a step of forming a dot pattern consisting of rectangular dots and grid-like spaces on a substrate, and The heat flow step of making the heat flow through the heating point pattern.

In addition, for the shape and size of the dot pattern, the width of the interval in the dot pattern is regarded as W, and when the height of the dot is regarded as H, the preferable range of the value of the aspect ratio H/W is such as resin composition. In the foregoing.

The substrate is not particularly limited as long as it is a substrate conventionally used as an object for forming a microlens pattern. As an example of a suitable substrate, a solid-state imaging element, a first planarization film, a color filter, and a second planarization film are formed on a silicon substrate. On this substrate, a first planarization film having a flat surface is formed so as to cover the solid-state imaging elements scattered at predetermined positions on the silicon substrate. On the first planarization film, a color filter is formed at a position above the position of each solid-state imaging element. Then, a second planarization film having a planar surface is formed so as to cover the color filter. In addition, in the substrate, the direction from the silicon substrate to the second planarization film side is regarded as upward, and the direction from the second planarization film to the silicon substrate side is regarded as downward.

Hereinafter, the method of forming the microlens pattern on the substrate will be described with reference to FIG. 1.

＜Steps to form dot pattern＞ As shown in FIG. 1(b), in order to form a microlens pattern on the substrate 10, first, a dot pattern 12 is formed on the substrate 10 using the above-mentioned resin composition. The method of forming the dot pattern 12 is not particularly limited. For example, as described above, the dot pattern 12 can be formed by a printing method such as an inkjet printing method. The dot pattern 12 can also be formed by a lithography method including patterning of exposure and development.

The detailed formula of the lithography method is appropriately selected according to the types of components contained in the resin composition or the composition of the resin composition.

For example, when using a positive photosensitive resin composition containing an alkali-soluble resin (A1) and a photosensitizer (B), which is a preferable resin composition, first, as shown in FIG. 1(a), the substrate 10 is coated The resin composition forms the coating film 11. The coating method is not particularly limited, and, for example, a well-known method using a roll coater or a spin coater can be used.

When the coating film 11 contains volatile components such as a solvent, the volatile components can be removed from the coating film 11 as necessary. As a method of removing volatile components, a method of placing the coating film 11 in a reduced pressure environment or a method of heating the coating film 11 is preferable. However, the coating film 11 is also easy to heat flow at low temperatures, so that the dot pattern system has excellent low temperature heat fluidity. Therefore, when removing volatile components from the coating film 11, if necessary, place it in a reduced pressure environment. It is preferable to heat the coating film 11 at a temperature of (Tg+50°C or less) for a short time. 120 seconds or less, preferably about 90 seconds or less.

Then, after the coating film 11 is exposed through a mask of a predetermined shape, the exposed coating film 11 is developed to form a dot pattern 12 as shown in FIG. 1(b).

Exposure is performed, for example, by irradiating active energy rays such as ultraviolet rays, excimer laser light, etc. Although the amount of irradiated energy rays also differs depending on the composition of the photosensitive resin composition, for example, it is preferably 30 mJ/cm ² or more and 2000 mJ/cm ² or less.

As the developing solution, for example, an organic alkali aqueous solution such as tetramethylammonium hydroxide (TMAH) aqueous solution or an inorganic alkali aqueous solution such as sodium hydroxide, potassium hydroxide, sodium metasilicate, and sodium phosphate can be used.

For the dot pattern 12 formed as above, bleaching by full exposure can be performed. With this bleaching, the transparency of the dot pattern 12 increases. By bleaching, the photoreaction system of the quinonediazide-containing compound-containing photosensitizer (B) contained in the resin composition occurs, and the transparency of the dot pattern 12 increases. As a method of bleaching, specifically, it is preferable to irradiate ultraviolet rays having a wavelength in the range of 300 nm to 450 nm. In addition, even if bleaching is not performed, when the transparency of the dot pattern 12 is good, bleaching can be omitted if necessary.

＜The heat flow step＞ Since the dot pattern 12 that has been bleached as necessary is heated, the dot pattern 12 can be heated. With this heat flow, a microlens pattern 13 is formed on the substrate 10.

The temperature of heat flow is preferably (Tg+5)°C or higher and 130°C or lower, more preferably (Tg+5)°C or higher and 100°C or lower. At a temperature within this range, when the dot pattern 12 formed by the resin composition is used for heat flow, the dot pattern 12 can be prevented from excessive heat flow, and the dot pattern 12 can easily flow to the desired degree. .

By the method described above, the dot pattern can have a good heat flow even at low temperatures, thereby making it possible to form a good microlens pattern. [Example]

Hereinafter, examples are given to illustrate the present invention in more detail. The present invention is not limited by these embodiments.

[Examples 1 to 4, Comparative Example 1 and Comparative Example 2] In Examples 1 to 4, it will be described below that the resin (A), the photosensitizer (B), and the solvent are uniformly mixed to prepare a photosensitive resin composition.

<Resin (A)> In each example and comparative example, 100 parts by mass of a copolymer containing units represented by the following formulas A-1, A-2 and A-3 in the mass ratio shown in Table 1 below was used as Resin (A). The mass average molecular weight (Mw) of the copolymer used in each example and comparative example is 8,000.

<Photosensitizer (B)> In each of the Examples and Comparative Examples, as the photosensitizer (B), the amount of the hydrogen atom in the hydroxyl group of the compound represented by the following formula shown in Table 1 was used through 1,2- Substituted by naphthoquinone diazide-5 sulfonyl group. The substitution rate of the hydrogen atom in the hydroxyl group of the sensitizer by the 1,2-naphthoquinonediazide-5-sulfonyl group is 98.7 mol%.

So that the solid content concentration became 24% by mass, 100 parts by mass of the resin (A) and the photosensitizer (B) in the amount described in Table 1 below were dissolved in propylene glycol monomethyl ether acetate to obtain each example And the resin composition of each comparative example. For the obtained resin composition, Tg was measured by a differential scanning calorimeter according to the aforementioned method. Table 1 shows the measurement results of Tg. The obtained resin composition was evaluated for low-temperature thermal fluidity according to the following method. Table 1 describes the evaluation results.

＜Evaluation of low temperature thermal fluidity＞ On the silicon substrate, the resin composition of each example and each comparative example was coated by a spin coater, and then baked at 90°C for 90 seconds to form a coating film with a thickness of 1.8 μm. For the formed coating film, after the exposure of the selected position is applied, an aqueous solution of tetramethylammonium hydroxide (TMAH) with a concentration of 2.38% by mass is used for 60 seconds to develop a dot pattern. The shape of the surface parallel to the surface direction of the substrate of the dots constituting the formed dot pattern is a square of 4 μm×4 μm. In addition, the width of the interval between the dots is 0.5 μm. After making the formed dot pattern heat flow under the conditions described in Table 1, the surface of the substrate was observed by electron microscopy to obtain electron microscopy images. From the obtained electron microscope image, the low-temperature thermal fluidity was evaluated according to the following criteria. ◎The four sides of the dots that make up the dot pattern are transformed into arcs protruding in the direction of the spacing, and the spacing between the dots can be clearly recognized. ○ Although the heat flow of the dot pattern is seen, it is difficult to visually recognize the interval between dots. ×The four sides of the dots forming the dot pattern are all straight lines, and no heat flow can be seen.

As can be seen from Table 1, when using a resin composition whose Tg of a resin film formed by using a resin composition measured by a specified method is below 70°C, even if it is a low temperature of about (Tg+30)°C, it is also used The dot pattern formed by the resin composition has good heat flow. On the other hand, it can be seen from the comparative example that when a resin composition with the above Tg value exceeding 70°C is used, the dot pattern formed by using the resin composition is hardly heated at a low temperature of about (Tg+30)°C flow.

10: substrate 11: Coating film 12: Dot pattern 13: Micro lens pattern

[Fig. 1] A diagram schematically showing a method of manufacturing a substrate with a microlens pattern.

10: substrate

11: Coating film

12: Dot pattern

13: Micro lens pattern

Claims (13)

A resin composition which is used in a method of forming a microlens pattern by heating a dot pattern formed by rectangular dots and grid-like spaces to flow the dot pattern heat. Form the resin composition of the aforementioned dot pattern, The aforementioned resin composition contains resin (A), The glass transition temperature Tg of the resin film formed by using the resin composition is 70°C or less, as measured by the method including the steps (1) to (4) below; (1) The step of spin-coating the aforementioned resin composition on a substrate to form a coating film, (2) The step of heating the aforementioned coating film at 100°C for 90 seconds to form a resin film, (3) Collect a sample for glass transition point measurement from the obtained resin film, and use the obtained sample to perform a differential scanning calorimeter (DSC) measurement to obtain a reversing heat flow curve, and (4) The step of reading the minimum value in the differential curve derived from the first derivative of the obtained reverse heat flow curve with the temperature as the glass transition temperature Tg, and determining the value of the glass transition temperature Tg. The resin composition of claim 1, which contains an alkali-soluble resin (A1) and a photosensitizer (B) as the resin (A). The resin composition of claim 2, wherein the content of the photosensitive agent (B) in the resin composition is 50% by mass or less relative to the mass of the resin (A). The resin composition of claim 2 or 3, wherein the alkali-soluble resin (A1) contains a (meth)acrylic resin containing a structural unit represented by the following formula (a1),

(In formula (a1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a single bond or an alkylene group having 1 to 5 carbon atoms, R ³ represents an alkyl group having 1 to 5 carbon atoms, and a represents An integer of 1 or more and 5 or less, b represents an integer of 0 or more and 4 or less, a+b is 5 or less, and when b is 2 or more, the plural R ³ may be the same or different). The resin composition according to claim 4, wherein the ratio of the mass of the structural unit represented by the aforementioned formula (a1) to the mass of the aforementioned (meth)acrylic resin is 20% by mass or more and 80% by mass or less. The resin composition according to claim 4 or 5, wherein the alkali-soluble resin (A1) further comprises a structural unit of an alkyl ester having 1 to 10 carbon atoms derived from (meth)acrylic acid. Such as the resin composition of any one of claims 1 to 6, in which The width of the aforementioned space is 0.2 μm or more and 2.0 μm or less, When the width of the aforementioned space is regarded as W and the height of the aforementioned dot is regarded as H, the aspect ratio indicated by H/W is 1.0 or more and 10.0 or less. The resin composition according to any one of claims 1 to 7, wherein the temperature of the aforementioned heat flow is (the aforementioned Tg+5)°C or more and 130°C or less. The resin composition of claim 8, wherein the temperature of the aforementioned heat flow is (the aforementioned Tg+5)°C or more and 100°C or less. A method for manufacturing a substrate with a microlens pattern, which includes: Using the resin composition of any one of claims 1 to 9, a step of forming a dot pattern consisting of rectangular dots and grid-like spaces on a substrate, and A heat flow step in which heat flows by heating the aforementioned dot pattern. Such as claim 10, the method for manufacturing a substrate with a microlens pattern, wherein The width of the aforementioned space is 0.2 μm or more and 2.0 μm or less, When the width of the aforementioned space is regarded as W and the height of the aforementioned dot is regarded as H, the aspect ratio shown by H/W is 1.0 or more and 10.0 or less, Formation of the aforementioned dot pattern is performed using the resin composition as in Claim 7. Such as claim 10, the method of manufacturing a substrate with a microlens pattern, wherein The temperature of the aforementioned heat flow is above (Tg+5)℃ above 130℃, The aforementioned dot pattern formation is performed using the resin composition as in Claim 8. Such as claim 10, the method of manufacturing a substrate with a microlens pattern, wherein The temperature of the aforementioned heat flow is above (Tg+5)℃ above 100℃, Formation of the aforementioned dot pattern is performed using the resin composition as in Claim 9.

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