JPH08325476A - Dam-forming photosensitive resin composition - Google Patents

Abstract

PURPOSE: To obtain a dam-forming photosensitive resin compsn. used in casting a liq. sealant to seal a semiconductor on a substrate board by compounding a specific particulate copolymer with a photopolymerizable compd. and a photopolymn. initiator. CONSTITUTION: This resin compsn., for forming a dam in casting a liq. sealant to seal a semiconductor on a substrate board, contains a particulate copolymer obtd. by copolymerizing an aliph. conjugated diene, an α, β-unsatd. carboxylic acid. and a monomer other than an aliph. conjugated diene and having at least two addition-polymerizable groups, a photopolymerizable compd. [e.g. styrene or a (meth)acry1ate], and a photopolymn. initiator (e.g. an α--diketone compd. such as diacetyl or benzil). Pref. the compsn. further contains an amine (e.g. ethylamine).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention casts a liquid sealant,
The present invention relates to a dam-forming photosensitive resin composition for forming a dam used when sealing a semiconductor on a substrate.

[0002]

2. Description of the Related Art Conventionally, resin encapsulation using various resins such as epoxy resin has been performed for encapsulation for the purpose of protecting elements such as integrated circuits (ICs). There are solid resin sealing called a molding method and liquid resin sealing called a potting or casting method. In order to meet the recent demand for smaller size and lighter weight, the IC mounting method is
An increasing number of methods called surface mounting, in which an element such as an IC is directly mounted on a substrate and sealed by liquid resin sealing.
In this liquid resin sealing, for example, a liquid sealing agent made of a liquid resin is poured from the upper part of the device, but there is a problem that the liquid sealing agent is cast on a portion other than the portion that should be protected originally, and high density is achieved. It was a factor that hindered the implementation. To prevent this, form a frame material by punching various substrate materials such as glass epoxy, paper phenol, etc. into the required shape, and bond it to form a fence in the required part before sealing, then apply a liquid sealant to the wall. The method of pouring inside (called casting method) is adopted. That is, a fence having a height of about 1 mm is formed around the element by a frame material so that the liquid sealing agent is prevented from being cast onto a portion other than the portion to be protected. This frame material is called a liquid resin sealing dam (hereinafter referred to as "dam"). The conventional dam is mainly made of a flaky material formed by punching as described above.

[0003]

As described above, in the conventional method, it takes a lot of time to form a large number of dams on the same substrate at one time in order to cope with high-density mounting of ICs. However, it is difficult to form the dam with high positional accuracy. Furthermore, since the dam is manually bonded, there is a risk of adhesive squeezing out and reliability deterioration due to poor adhesion.
In addition, changing the shape of the dam according to various ICs is very time-consuming. An object of the present invention is to provide a photosensitive resin composition for dam formation in order to solve the above problems. Another object of the present invention is to form a film of a photosensitive resin composition directly on a substrate, expose it, and develop it to form a dam, and form a dam of any shape by exposure and development. The formed dam has good adhesion to the substrate without the use of an adhesive, and also has good heat resistance to heat treatment for curing the encapsulant and heat during soldering treatment. To provide a photosensitive resin composition for forming.

[0004]

According to the present invention, the above-mentioned objects of the present invention are: (1) Aliphatic conjugated diene monomer α, β-unsaturated carboxylic acid monomer Aliphatic conjugated diene monomer Except for the above, a particulate copolymer obtained by copolymerizing a monomer having at least two addition-polymerizable groups (2) Photopolymerizable compound and (3) Photopolymerization initiator And a photosensitive resin composition for dam formation (hereinafter referred to as "photosensitive resin composition"). Hereinafter, the present invention will be specifically described, but the purpose, constitution and effect of the present invention will be clarified by this.

Particulate Copolymer The particulate copolymer used in the present invention (hereinafter referred to as "copolymer (I)") is an aliphatic conjugated diene monomer, α, β-unsaturated carboxylic acid. A monomer having at least two addition-polymerizable groups other than the monomer and the aliphatic conjugated diene monomer, and if necessary, each component of the above-mentioned and other copolymerizable monomers It is a particulate copolymer obtained by copolymerization.

Examples of the above-mentioned monomer component include compounds having an aliphatic carbon-carbon conjugated double bond having 4 to 8 carbon atoms such as butadiene, isoprene, dimethylbutadiene and chloroprene. Particularly, butadiene and isoprene are preferable. As the monomer component, for example, acrylic acid, methacrylic acid, maleic acid,
Examples thereof include fumaric acid, itaconic acid, tetraconic acid, and other aliphatic carboxylic acid compounds having 3 to 8 carbon atoms and having a carbon-carbon conjugated double bond in the molecule. Particularly, acrylic acid, methacrylic acid and itaconic acid are preferable. Examples of the monomer component include ethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, propylene glycol diacrylate, divinylbenzene, trivinylbenzene, penta Of aliphatic polyols having 2 to 8 carbon atoms such as erythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-heptanediol di (meth) acrylate. (Meth) acrylic acid diester to tetraester compounds may be mentioned. In particular, ethylene glycol dimethacrylate, propylene glycol dimethacrylate and divinylbenzene are preferable.
Further, as the monomer component, for example, styrene,
α-methylstyrene, vinyltoluene, acrylonitrile, vinyl chloride, vinylidene chloride, (meth) acrylamide, methyl (meth) acrylamide, methyl (meth) acrylate, ethyl (meth) acrylate,
Examples of compounds having a carbon-carbon double bond or a carbon-nitrogen double bond such as n-propyl (meth) acrylate and 2-ethylhexyl (meth) acrylate and copolymerizable with the monomer component and it can. Particularly, ethyl acrylate, methyl methacrylate, ethyl methacrylate and styrene are preferable. Each of the monomer components may be used alone or as a mixture of a plurality of different compounds.

The proportion of repeating units derived from each monomer component contained in the copolymer (I) is such that the total amount of the copolymer (I) is 100 mol% and the repeating units derived from the monomer component. / Repeating unit derived from monomer component / Repeating unit derived from monomer component / Repeating unit derived from monomer component is 10 to 95 / 0.1 to 30 / 0.1
.About.20 / 0 to 70 mol%, preferably 30 to 85/0.
It is 1 to 20 / 0.5 to 10/0 to 50 mol%. If the proportion of the repeating units derived from the monomer component in the copolymer (I) is less than 10 mol%, the strength of the photosensitive resin composition cured by exposure is low, and if it exceeds 95 mol%, the photosensitivity is increased. This is not preferable because the developing characteristics of the resin composition deteriorate. Further, when the proportion of the repeating unit derived from the monomer component in the copolymer (I) is less than 0.1 mol%, the developing property of the photosensitive resin composition is deteriorated, and when it exceeds 30 mol%. It is not preferable because the photosensitive resin composition cured by exposure becomes hard and brittle. Further, if the proportion of the repeating units derived from the monomer component in the copolymer (I) is less than 0.1 mol%, the developing characteristics of the photosensitive resin composition will be deteriorated, and if it exceeds 20 mol%. The compatibility of the copolymer (I) contained in the photosensitive resin composition and the photopolymerizable compound is deteriorated and the photosensitive characteristics are deteriorated, and the strength of the photosensitive resin composition cured by exposure is lowered. Is not preferred.

The polymerization method of the copolymer (I) is emulsion polymerization,
Although methods such as solution polymerization, suspension polymerization, and bulk polymerization can be adopted, emulsion polymerization or suspension polymerization with a radical polymerization initiator is preferable from the viewpoint that the copolymer (I) can be directly obtained in the form of particles. . In particular, the emulsion polymerization method is preferably used in view of the size of particles formed and the uniformity of particle size. As a result, the copolymer (I) takes a particulate shape, and the particle surface of the particulate copolymer becomes hydrophilic and the inside of the particle becomes hydrophobic, whereby the developability of the photosensitive resin composition is improved. It becomes favorable, and the water resistance of the photosensitive resin composition cured by exposure is further improved. In the emulsion polymerization method, each of the monomer components, the radical polymerization initiator, and a polymerization agent such as an emulsifier optionally added may be mixed in the total amount at the start of the reaction, or may be mixed after the reaction. You may add and mix at the time. Further, the reaction of the emulsion polymerization, in the reaction vessel from which oxygen of the radical inhibiting function has been removed,
It can be carried out by either a continuous system or a batch system, and stirring conditions and the like can be arbitrarily set according to the properties of the target copolymer (I). The polymerization temperature of the emulsion polymerization method is 0.
The temperature is preferably -60 ° C, and heating or cooling may be performed during the reaction. Examples of the radical polymerization initiator include organic peroxides such as benzoin peroxide, cumene hydroperoxide, paramenthane hydroperoxide and lauroyl peroxide, diazo compounds such as azobisisobutyronitrile, potassium persulfate and ammonium persulfate. Inorganic peroxides, redox compounds such as organic compound-iron sulfate combinations, and the like can be mentioned. The proportion of the radical polymerization initiator used can be appropriately selected depending on the type of the radical polymerization initiator used, but is usually 0.01 to 5 parts by weight based on 100 parts by weight of the total amount of the monomer components. Is preferred.

In the emulsion polymerization method, as an emulsifier used as necessary, sodium lauryl sulfate,
Examples thereof include anionic emulsifiers such as various long-chain alkyl sulfates, long-chain alkyl sulfonates, and long-chain alkyl carboxylates exemplified by sodium dodecylbenzenesulfonate, potassium fatty acid, potassium rosinate and the like. Furthermore, a nonionic emulsifier such as polyethylene glycol nonyl phenyl ether can also be used. The use ratio of the emulsifier is 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the monomer components used. The copolymer (I) obtained by emulsion polymerization is usually prepared by adding an inorganic salt to the emulsion polymerization reaction solution, coagulating the salt, filtering, collecting and drying. The copolymer (I) used in the present invention has a particle shape, but its average particle diameter is 0.03 μm (30 nm) to 1 μm (1,000 nm).
Is preferable, and particularly preferably 0.05 μm (50 nm)
˜0.3 μm (300 nm). The copolymer (I) used in the present invention includes two or more copolymers (I) having different kinds of monomer components, composition ratios or average particle diameters.
It is also possible to use a combination of two or more species.

Photopolymerizable compound In the photosensitive resin composition of the present invention, examples of the photopolymerizable compound include styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene and diisopropenyl. Aromatic vinyl compounds such as benzene and divinylbenzene; unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (Meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth)
Acrylic ester or methacrylic acid ester of alkyl alcohol such as acrylate, n-octyl (meth) acrylate and lauryl (meth) acrylate; Hydroxyalkyl alcohol such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate Acrylic acid ester or methacrylic acid ester; methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate or other alkoxyalkyl alcohol acrylic acid ester or methacrylic acid ester; methoxyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) Acrylic ester or methacrylic ester of alkoxy alkylene glycol such as acrylate; trifluoroethyl (meth) acrylate Acrylic acid or methacrylic acid ester of fluoroalkyl alcohol such as pentafluoropropyl (meth) acrylate; acrylic acid, methacrylic acid, maleic acid, fumaric acid, maleic anhydride, crotonic acid, itaconic acid, itaconic anhydride, citracone Α, β-Unsaturated carboxylic acids such as acids, mesaconic acid and cinnamic acid; monoalkyl esters of unsaturated polycarboxylic acids such as maleic acid monoester, fumaric acid monoester and itaconic acid monoester;

Unsaturation of dimethyl maleate, diethyl maleate, dibutyl maleate, dioctyl maleate, diethyl fumarate, dibutyl fumarate, dioctyl fumarate, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, dioctyl itaconate, etc. Dialkyl ester of polycarboxylic acid; (meth) acrylamide, N, N'-methylenebis (meth) acrylamide,
(Meth) acrylamide such as N, N′-hexamethylenebis (meth) acrylamide; (meth) acrylate of alkylene glycol such as ethylene glycol (meth) acrylate and propylene glycol (meth) acrylate; ethylene glycol di (meth) acrylate, The number of repetitions of di (meth) acrylate of alkylene glycol such as propylene glycol di (meth) acrylate; poly (ethylene glycol) (meth) acrylate (for example, nonaethylene glycol methacrylate), poly (propylene glycol) (meth) acrylate is 2
Poly (alkylene glycol) (meth) acrylate having a repeating number of 2 to 23, such as poly (ethylene glycol) di (meth) acrylate and poly (propylene glycol) di (meth) acrylate. Di (meth) acrylate; glycerin, pentaerythritol, trimethylolalkane,
In addition to di-, tri- or tetra (meth) acrylates of aliphatic polyhydric alcohols such as tetramethylolalkane,
Carbon-carbon double bond or carbon-nitrogen double bond that initiates polymerization upon exposure to light, such as oligoacrylate, vinyl chloride, vinyl acetate, cyanoethyl acrylate, cinnamic acid ester, crotonic acid ester, and dicyclopentadiene ethylidene orbornene. A compound having Of the above-mentioned photopolymerizable compounds, various acrylates and various methacrylates are particularly preferable.

As the photopolymerizable compound, the above compounds may be used alone or as a mixture of a plurality of different compounds,
It can be arbitrarily selected according to the developability of the photosensitive resin composition, the properties of the photosensitive resin composition cured by exposure, and the like. The photopolymerizable compound can be used in any ratio so that the fluidity of the photosensitive resin composition of the present invention becomes waxy, rubbery or low-viscosity liquid, but preferably the copolymer (I ) 10 to 200 relative to 100 parts by weight
It is used in parts by weight, particularly preferably 10 to 100 parts by weight. When the proportion of the photopolymerizable compound used is less than 10 parts by weight, the strength of the photosensitive resin composition cured by exposure is deteriorated, and when it exceeds 200 parts by weight, the fluidity of the photosensitive resin composition becomes too large. , It may be difficult to form a dam of sufficient height.

Photopolymerization Initiator In the present invention, the photopolymerization initiator contained in the photosensitive resin composition is, for example, α-type such as diacetyl or benzyl.
Diketone compounds; benzoin, pivaloin, and other acyloin compounds; benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and other acyloin ether compounds; anthraquinone, 1,4-naphthoquinone, and other quinone compounds; 2,2-dimethoxyphenylacetophenone, An acetophenone compound such as trichloroacetophenone; a so-called photosensitizer having a function of sensitizing the photopolymerizability of a photopolymerizable compound such as a benzophenone or a benzophenone compound such as methyl-o-benzoylbenzoate can be mentioned. These photopolymerization initiators are
They can be used alone or in combination of two or more. In the photosensitive resin composition of the present invention, the proportion of the photopolymerization initiator used is 0.1 to 2 with respect to 100 parts by weight of the copolymer (I).
It is 0 parts by weight, preferably 1 to 10 parts by weight. If the proportion of the photopolymerization initiator used is less than 0.1 parts by weight, the photosensitive resin composition will not be sufficiently cured by exposure, and if it exceeds 20 parts by weight, the photopolymerization will start at the light irradiation amount during exposure. Not only are all the agents uneconomical because they do not participate in the photopolymerization reaction, but they are also compatible with the copolymer (I), the photopolymerizable compound, the compound having an amino group used as necessary, and other additives. The compatibility may be deteriorated, and a uniform photosensitive resin composition may not be obtained.

Compound Having Amino Group The photosensitive resin composition of the present invention has an amino group in order to improve the developability of the photosensitive resin composition, particularly when water is used as a developer. Further compounds can be added. Examples of the compound having an amino group include primary amines such as ethylamine and propylamine; secondary amines such as diethylamine and dibutylamine;
Trialkylamines such as trimethylamine, triethylamine, tripropylamine, ethyldimethylamine and diethylmethylamine; triethanolamines such as triethanolamine and tripropanolamine; N, N
-Dimethylaminoethyl (meth) acrylate, N, N
-Acrylic acid ester or methacrylic acid ester of alkyl alcohol having a dialkylamino group such as diethylaminoethyl (meth) acrylate; having a dialkylamino group such as dimethylaminoethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide (meth) Examples thereof include compounds having an amino group such as acrylamide. In the photosensitive resin composition of the present invention, particularly when a developing method using water as a developer is used, it is preferable to use a tertiary amine as the compound having an amino group. Further, in order to increase the strength of the photosensitive resin composition cured by exposure, the compound having an amino group is preferably a compound having a carbon-carbon double bond which is polymerized by exposure. Examples of the compound having an amino group include, among the above examples, an α, β-unsaturated group such as a tertiary amino group-containing (meth) acrylate and a tertiary amino group-containing (meth) acrylamide, and a tertiary amino group. Compounds containing groups are preferred. These compounds having an amino group can be used alone or in combination of two or more kinds.

In the photosensitive resin composition of the present invention, the ratio of the compound having an amino group used is based on the total amount of carboxylic acid groups derived from the monomer components contained in the copolymer (I). It is possible to use a compound having an amino group such that the amino group has an amount of 0 to 2 molar equivalents. In particular, when water is used as a developing solution in the method for developing the photosensitive resin composition, the amino group is 0.5 to 2 mole equivalent, preferably 0.6 to 2 with respect to the total of the carboxylic acid groups. It is preferable to use a compound having an amino group so that the amount is 1.5 molar equivalents. The compound having an amino group can be added and mixed when the photosensitive resin composition of the present invention is prepared.

Various compounding agents In the photosensitive resin composition of the present invention, if necessary, various compounding agents such as a thermal polymerization inhibitor, a solvent, a sensitizer other than the above, a surfactant, an inorganic filler such as a filler, and the like. Can be blended. The thermal polymerization inhibitor is added for the purpose of increasing the storage stability of the photosensitive resin composition of the present invention, and for example, hydroquinone, hydroquinone monomethyl ether, mono-tert-butylhydroquinone, catechol, p-
Methoxyphenol, p-tert-butylcatechol, 2,6-di-tert-butyl-p-cresol,
Examples thereof include hydroxyaromatic compounds such as pyrogallol; quinone compounds such as benzoquinone, p-toluquinone and p-xyloquinone; amine compounds such as phenol-α-naphthylamine. In the photosensitive resin composition of the present invention, the use ratio of the thermal polymerization inhibitor is 0.001 to 2 parts by weight based on 100 parts by weight of the photosensitive resin composition.

The solvent is added in a small amount in order to adjust the flow characteristics of the photosensitive resin composition of the present invention and to improve the printing characteristics such as screen printing. Examples of the solvent include water, ethyl alcohol, propyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol. Methyl ether acetate, propylene glycol propyl ether acetate, propylene glycol methyl ether propionate, toluene, xylene, methyl ethyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, ethyl 2-hydroxypropionate, 2-hydroxy-2 -Ethyl methyl propionate, 2-methoxy-2 Methylpropionic acid methyl, ethyl ethoxy acetate, hydroxyethyl acetate, 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate,
Ethyl 3-ethoxypropionate, ethyl 3-methoxypropionate, methyl 3-methoxy-2-methylpropionate, ethyl acetate, butyl acetate, methyl pyruvate,
Examples include ethyl pyruvate and the like. Furthermore, N
-Methylformamide, N, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzylethylether, dihexylether, acetonylacetone, isophorone, Caproic acid, caprylic acid, 1-octanol, 1
A high boiling solvent such as nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ-butyrolactone, ethylene carbonate, propylene carbonate or ethylene glycol monophenyl ether acetate may be added. These solvents may be used alone or in combination of two or more.

The sensitizer is added to improve the sensitivity of the photosensitive resin composition of the present invention. For example, 2H-pyrido- [3,2-b] -1,4-oxazine- 3 (4H) -ones, 10H-pyrido- [3,2-
Examples thereof include dye compounds such as b]-(1,4 ′)-benzothiazines, urazoles, hydantoins, parpituric acids, glycine anhydrides, 1-hydroxybenzotriazoles, alloxanes, and maleimides. Further, the surfactant is compatible with the copolymer (I), the photopolymerizable compound or the photopolymerization initiator contained in the photosensitive resin composition of the present invention, the coating property and the developing property of the photosensitive resin composition. It is added to improve the properties. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether,
In addition to polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, etc., fluorine-based anionic surfactant, fluorine-based cationic surfactant, fluorine-based nonion A surfactant and the like can be mentioned. In addition, these surfactants may be used alone or
A mixture of two or more species can be used. The amount of these surfactants to be blended is preferably 2 parts by weight or less based on 100 parts by weight of the photosensitive resin composition. Furthermore, the photosensitive resin composition of the present invention may contain a dye or a pigment in order to visualize the latent image in the light-irradiated portion at the time of exposure, and an adhesive aid in order to further improve the adhesiveness. You can also do it. Further, if necessary, a storage stabilizer, a defoaming agent, etc. may be added.

Preparation of Photosensitive Resin Composition The photosensitive resin composition of the present invention comprises a copolymer (I), a photopolymerizable compound and a photopolymerization initiator, and optionally a compound having an amino group. , Mix various additives,
It can be obtained by sufficiently stirring with a kneader, intermixer or the like while heating. If necessary,
It is also possible to use a mesh or the like to perform filtration for the purpose of removing foreign matter. The resulting photosensitive resin composition can be freely designed to have a wax-like or rubber-like state having no fluidity, or a low-viscosity liquid having excellent fluidity.

Formation of Dam A dam used for sealing with a liquid resin generally has a height of 0.1 to 1 m around the element sealed with a liquid sealant.
It is formed as a frame having a cross section of m and a width of 0.1 to 2 mm. To form a dam using the photosensitive resin composition of the present invention, specifically, (a) a film of the photosensitive resin composition is formed on a substrate, and (b) pattern exposure is performed in the shape of the dam,
(C) Perform pattern formation by developing with a developing solution,
(D) It is performed by performing a heat treatment as needed.

As the method for forming the film of the photosensitive resin composition on the substrate on which the device is mounted, various methods are used depending on the fluidity of the photosensitive resin composition prepared as described above. . Specifically, (i) in the case of a non-flowable wax-like or rubber-like photosensitive resin composition, for example, (a) via a glass or silicon flat plate spacer having an appropriate thickness. The photosensitive resin composition is rolled and formed into a sheet and then peeled off, or (b) a roll coater or the like is applied onto a support such as a polyethylene film to form a film-like film, and then peeled off ( c) After being molded into a sheet or film shape by molding into a sheet having a constant film thickness by a compression molding machine, an extrusion molding machine, etc., the sheet-shaped or film-shaped photosensitive resin composition is added. ,
A method of press-bonding to a substrate on which an element to be sealed with a liquid resin is mounted to form a film; (ii) In the case of a photosensitive resin composition exhibiting fluidity,
For example, (d) spin coater (spin coater), cast coater (calendar coater), roll coater (roll coater), etc., and precoat (prebak) to coat the photosensitive resin composition. Or a film forming method such as (e) forming a film of the photosensitive resin composition directly on the substrate by (e) a printing machine such as a screen printing machine; Done.

Next, the substrate provided with the film of the photosensitive resin composition is subjected to pattern exposure through a photomask so that a dam having a predetermined pattern shape is formed. As the light used for the exposure, light having an arbitrary wavelength can be used as long as it can photo-cur the photosensitive resin composition. For example, ultraviolet rays such as g rays and i rays, far ultraviolet rays such as excimer lasers, X rays such as synchrotron radiation, and charged particle rays such as electron beams can be used. As the exposure method, specifically, a method of pattern-irradiating ultraviolet rays emitted from a fluorescent lamp, a chemical lamp, a high-pressure mercury lamp, or the like through a mask, a laser beam of a visible light laser, an ultraviolet laser, an excimer laser, or the like is scanned to a predetermined value. And a collective exposure method using an electro-optical mask such as a liquid crystal display device or a CRT in some cases. In the above method of pattern irradiation through a mask, it is preferable to provide alignment marks on the substrate and the mask for aligning the mask. A negative mask for photolithography can be used as the mask, but the exposure is preferably proximity exposure or contact exposure. In addition, the photosensitive resin composition of the present invention accelerates photocuring of the photosensitive resin composition produced by exposure by performing an operation of heating at 70 to 140 ° C. after exposure and before development, and The effect can be further improved.

Subsequently, the exposed photosensitive resin composition is subjected to pattern formation by development. The development process for forming the pattern can be carried out under ordinary photolithography conditions. As the developing solution, water; an alkaline aqueous solution such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine,
Methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo An alkaline aqueous solution obtained by dissolving an alkaline compound such as [4.3.0] -5-nonene in a concentration of, for example, 1 to 10% by weight; an organic solvent such as alcohols such as methanol, ethanol, isopropanol, butanol, and the like.
Ketones such as acetone and methyl isobutyl ketone, and hydrocarbon solvents such as toluene and hexane can be used. In particular, it is preferable to use water or an alkaline aqueous solution, and for safety, it is particularly preferable to use water. When the developer is water or an alkaline aqueous solution, a water-soluble organic solvent, for example, alcohols such as methanol and ethanol, or a surfactant may be added in an appropriate amount and used. As a developing method, a paddle developing method, a dip developing method, a spray developing method, or the like can be used, and in some cases, brushing can be used together. Development is preferably carried out at 20 to 60 ° C. When the developing solution is other than water, it is usually washed (rinsed) with water after development.

The formed pattern is subjected to heat treatment (referred to as post cure) if necessary. The heat treatment condition is appropriately selected depending on the composition of the photosensitive resin composition and the shape of the dam, but is usually 60 to 150 ° C. and 0.5 to
120 minutes heat treatment, warm air type heater, infrared type heater,
It is performed using a hot plate or the like. By such heat treatment, curing of the photosensitive resin composition is promoted, and the effect of the present invention is further improved.

[0025]

The present invention will be described in detail below with reference to examples.

<Synthesis of Copolymer (I)> Synthesis Example 1 Butadiene 71 parts by weight Methyl methacrylate 15 parts by weight Ethylene glycol dimethacrylate 4 parts by weight Methacrylic acid 10 parts by weight Sodium lauryl sulfate 3 parts by weight Ammonium persulfate 0.25 parts by weight Cyanoethylated diethanolamine (0.15 parts by weight) and water (200 parts by weight) were charged into an autoclave, and the mixture was stirred for 20 minutes.
Emulsion polymerization was carried out at 8 ° C for 8 hours. Then, hydroxylamine sulfate is added to terminate the polymerization, calcium chloride is added to coagulate the polymer, and the coagulated product is separated by filtration, dehydrated and dried to obtain the copolymer (I). Was recovered. The obtained copolymer (I) was a particulate polymer having an average particle size of 67 nm. This copolymer (I) is replaced with the copolymer (I
-1).

Synthesis Example 2 Butadiene 70 parts by weight Ethyl methacrylate 18 parts by weight Divinylbenzene 2 parts by weight Methacrylic acid 10 parts by weight Sodium dodecylbenzene sulfonate 2 parts by weight Ammonium persulfate 0.25 parts by weight Cyanoethylated diethanolamine 0.15 parts by weight and water Polymerization and copolymer recovery were performed in the same manner as in Synthesis Example 1 except that 200 parts by weight was used. The obtained copolymer (I) has an average particle size of 9
It was a 3 nm particulate polymer. This copolymer (I)
Is referred to as a copolymer (I-2).

Example 1 <Production of Photosensitive Resin Composition> As a particulate copolymer, 100 parts by weight of the copolymer (I-1) obtained in Synthesis Example 1 As a photopolymerizable compound, nonaethylene glycol methacrylate 10 Parts by weight trimethylolpropane trimethacrylate 10 parts by weight As a compound having an amino group, N, N-dimethylaminopropylacrylamide 10 parts by weight As a photopolymerization initiator, 2,2-dimethoxyphenylacetophenone 3 parts by weight As a thermal polymerization inhibitor, 0.5 parts by weight of p-tert-butylcatechol was mixed and stirred with a kneader at 50 ° C. for 30 minutes to obtain a photosensitive resin composition. The photosensitive resin composition obtained was in the form of a transparent wax. This photosensitive resin composition is referred to as composition (1).

<Formation and Evaluation of Dam> Composition (1) is sandwiched between two polyester sheets, and the temperature is 100 ° C. and 100 Kg /
Press-molded under conditions of cm ² and 15 seconds, thickness 1.0 mm
Then, a 80 mm × 80 mm photosensitive resin film was prepared. Then, one of the polyester sheet is peeled off, immediately pressed to a glass epoxy substrate, the remaining polyester sheet is peeled off, after forming a film of the photosensitive resin composition on the substrate, followed by exposure and development, Composition (1)
A substrate having a dam made of the cured product of was obtained. For exposure, an exposure machine (JE-A3-SS) manufactured by JEOL Seiki Co., Ltd. was used, and ultraviolet rays (main ultraviolet ray wavelength 365 nm) were irradiated for 90 seconds. The mask pattern has a line width of 1 m as shown in Fig. 1.
A m-shaped pattern of 20 mm × 20 mm was used.
Development is performed by JEOL Seiki Co., Ltd. development machine (JOW-A-4
P) was used and brushing was performed for 5 minutes in warm water at 30 ° C. The obtained dam was faithful to the dimensional accuracy of the mask pattern, there was no undeveloped portion of undeveloped areas, no scum, and neither meandering of the pattern nor peeling from the substrate. Next, a liquid sealant (chip coat 8308) manufactured by Hokuriku Paint Co., Ltd. was cast in the dam and heated at 120 ° C. for 120 minutes. The dam was not deformed or peeled by the heat treatment for curing the sealant, and the liquid sealant formed a cured product inside the dam according to the pattern shape of the dam. Subsequently, the substrate was immersed in a solder bath at 320 ° C. for 15 seconds, but no change in appearance was observed in the dam and the sealed portion.

Example 2 <Production of Photosensitive Resin Composition> The same procedure as in Example 1 was carried out except that 100 parts by weight of the copolymer (I-2) obtained in Synthesis Example 2 was used as the particulate copolymer. Thus, a photosensitive resin composition was obtained. The photosensitive resin composition obtained was in the form of a transparent wax. This photosensitive resin composition is referred to as composition (2). <Dam Formation and Evaluation> A substrate having a dam composed of the composition (2) was obtained in the same manner as in Example 1 except that the composition (2) was used. The obtained dam was faithful to the dimensional accuracy of the mask pattern, and did not meander in the pattern or peel off from the substrate. Further, as in Example 1, the liquid sealant was cured and further immersed in a solder bath, but there was no deformation or peeling of the dam.

Example 3 <Formation and Evaluation of Dam> A dam made of the composition (1) was prepared in the same manner as in Example 1 except that the mask pattern used during exposure was changed to the pattern shape shown in FIG. A substrate having is obtained. The mask pattern used has a line width of 0.5 mm and a frame pattern of 8 mm × 8 mm as shown in FIG.
A pattern was used in which 5 pieces were arranged in the vertical and horizontal directions at intervals of 5 mm, and a total of 25 pieces were arranged. The time required for pattern formation was the same as that of Example 1, although the dam pattern became smaller and the number of dams increased. The obtained dam was faithful to the dimensional accuracy of the mask pattern, and did not meander in the pattern or peel off from the substrate. Further, as in Example 1, the liquid sealant was cured and further immersed in a solder bath, but there was no deformation or peeling of the dam.

[0032]

The dam-forming photosensitive resin composition of the present invention forms a film of the photosensitive resin composition directly on a substrate,
It can be exposed and developed to form dams of any shape. The formed dams have good adhesion to substrates without the use of adhesives, and heat treatment for curing liquid encapsulants. It also has good heat resistance to heating during soldering. Therefore, the dam-forming photosensitive resin composition of the present invention is a photosensitive resin composition for dam formation for casting a liquid encapsulant to form a dam used for encapsulating a semiconductor on a substrate. It can be preferably used.

[0033]

[Brief description of drawings]

1 and 2 are schematic views of a mask pattern used for exposure in the embodiment of the present invention.

Claims (2)

[Claims] 1. A photosensitive resin composition for forming a dam, for forming a dam used when a liquid sealing agent is cast to seal a semiconductor on a substrate, comprising: (1) an aliphatic conjugate Diene monomer α, β-unsaturated carboxylic acid monomer Granular copolymer obtained by copolymerizing monomers having at least two addition-polymerizable groups except aliphatic conjugated diene monomers Combined (2) Photopolymerizable compound and (3) Photopolymerization initiator 2. The photosensitive resin composition for dam formation according to claim 1, wherein the photosensitive resin composition for dam formation further contains (4) a compound having an amino group.