JP2011231137A - Epoxy resin composition for seal-filling semiconductor and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition for seal-filling a semiconductor, which achieves excellent connection reliability and sufficiently suppresses occurrence of voids in a resin during connection when used as a resin composition for seal-filling a semiconductor for a previous feed method and a semiconductor apparatus using the same.SOLUTION: The epoxy resin composition for seal-filling a semiconductor is used for electrically connecting a semiconductor chip provided with a plurality of bumps to a substrate having a plurality of electrodes (tin or solder exists on at least either of the surfaces of the bumps and the surfaces of the electrodes). The epoxy resin composition comprises an epoxy resin, a curing agent and a flux agent as essential components. The connection is carried out by a prescribed method in the epoxy resin composition for seal-filling a semiconductor.

Description

  The present invention relates to an epoxy resin composition for semiconductor sealing filling and a semiconductor device manufactured using the same.

In recent years, with the progress of miniaturization and high functionality of electronic devices, semiconductor devices are required to be miniaturized, thinned, and improved in electrical characteristics (corresponding to high-frequency transmission, etc.). Along with this, the transition from the conventional method of mounting a semiconductor chip on a substrate by wire bonding to the flip chip connection method in which conductive bump electrodes called bumps are formed on the semiconductor chip and directly connected to the substrate electrode has begun. Yes.
As bumps formed on the semiconductor chip, bumps made of solder or gold are used, but in order to cope with the recent fine connection, a solder layer or a tin layer is formed on the tip of the copper bump or copper pillar. Bumps having a formed structure have been used.
In addition, for high reliability, connection by metal bonding is required. Only solder bonding using solder bumps or metal bonding using bumps with a structure in which a solder layer or tin layer is formed on the tip of a copper pillar is required. In addition, even when copper bumps or gold bumps are used, a connection method in which a solder layer or a tin layer is formed on the substrate electrode side and metal bonding is employed.

  Furthermore, in the flip-chip connection method, thermal stress derived from the difference in thermal expansion coefficient between the semiconductor chip and the substrate may concentrate on the connection part and destroy the connection part. In order to increase, it is necessary to seal and fill the gap between the semiconductor chip and the substrate with resin. In general, sealing filling with a resin employs a method in which after a semiconductor chip and a substrate are connected using solder or the like, a liquid sealing resin is injected into the gap using a capillary phenomenon.

  When connecting the chip and the substrate, a flux composed of rosin, organic acid, or the like is used in order to reduce and remove the oxide film on the solder surface to facilitate metal bonding. If residual flux remains, it may cause bubbles called voids when liquid resin is injected. Corrosion of wiring may occur due to acid components, reducing connection reliability. The process to do was essential. However, since the gap between the semiconductor chip and the substrate is narrowed as the connection pitch is narrowed, it may be difficult to clean the flux residue. Furthermore, it takes a long time to inject the liquid resin into a narrow gap between the semiconductor chip and the substrate, resulting in a decrease in productivity.

  In order to solve the problem of such a liquid sealing resin, after supplying the sealing resin to the substrate using a sealing resin having the property of reducing and removing the oxide film on the solder surface (flux activity), the semiconductor At the same time that the chip and the substrate are connected, a gap between the semiconductor chip and the substrate is sealed and filled with a resin, and a connection method called a pre-feed method has been proposed that makes it possible to omit cleaning of the flux residue. A sealing resin corresponding to a connection method has been developed (see, for example, Patent Documents 1 to 3).

JP 2003-138100 A JP 2005-320368 A JP 2009-24099 A

  However, in the conventional first supply method, when metal bonding is performed, since the resin is exposed to a temperature higher than the melting point of solder or tin, bubbles called voids due to volatilization of low molecular weight components are generated in the resin. The problem is that the connection reliability is lowered. Further, in the conventional first supply method, the resin is cured before the molten solder or tin is sufficiently wetted with the substrate electrode, and the resin or the inorganic filler to be blended for low thermal expansion is sandwiched between the connection portions (trapping). As a result, there is a problem that poor conduction occurs or cracks occur in the connection portion, resulting in a decrease in connection reliability.

  Therefore, the present invention provides excellent connection reliability when used as a resin composition for semiconductor sealing filling for a pre-supply system, and sufficiently suppresses the generation of voids in the resin during connection. It is an object of the present invention to provide an epoxy resin composition for semiconductor sealing filling that can be performed, and a semiconductor device using the same.

  In view of the above circumstances, the present invention provides a semiconductor chip having a plurality of bumps, a substrate having a plurality of electrodes (provided that tin or solder exists on at least one surface of the bumps and the electrodes), and An epoxy resin composition for semiconductor sealing filling used for electrical connection, wherein the epoxy resin composition includes an epoxy resin, a curing agent, and a flux agent as essential components, and the above connection is an epoxy resin composition A first step of pressing the semiconductor chip against the substrate at a temperature higher than the melting point or softening point of the fluxing agent and lower than the melting point of solder or tin, after supplying the semiconductor chip to the bump forming surface of the semiconductor chip or the electrode surface of the substrate; Alternatively, heating is performed so that the melting point of tin is equal to or higher than the melting point of tin, and the first step is performed by a connection method including a second step of connecting the bump and the electrode by metal bonding. The semiconductor in which the gelation time of the epoxy resin composition at the heating temperature is longer than the heating time of the first step, and the gelation time of the epoxy resin composition at the heating temperature of the second step is less than the heating time of the second step An epoxy resin composition for sealing filling is provided.

  According to such an epoxy resin composition for semiconductor sealing filling, when used as a resin composition for semiconductor sealing filling for a pre-feeding method, excellent connection reliability is achieved, and the resin during connection It is possible to sufficiently suppress the generation of voids.

  The melting point or softening point of the fluxing agent is a temperature substantially equal to the activation temperature of the fluxing agent, as will be apparent from the reference examples described later. The “gelation time of the epoxy resin composition” can be obtained by, for example, placing the film-like epoxy resin composition on a hot plate at a predetermined temperature and measuring the time until stirring with a spatula becomes impossible. it can.

  The fluxing agent is preferably solid at room temperature, and the melting point of the fluxing agent is preferably lower than the melting point of solder or tin. Thereby, storage stability improves.

  It is preferable that the said epoxy resin composition for semiconductor sealing filling is formed in the film form from the point which can improve handleability.

  Furthermore, the present invention provides a semiconductor chip on which a plurality of bumps are formed, a substrate having a plurality of electrodes electrically connected to the bumps, and tin or solder on at least one surface of the bumps and electrodes. ), And a semiconductor device comprising a sealing resin that is made of a cured product of the epoxy resin composition for semiconductor sealing filling of the present invention and seals a gap between the semiconductor chip and the substrate.

  Such a semiconductor device is excellent in connection reliability because it uses the epoxy resin composition for semiconductor sealing filling of the present invention.

  According to the present invention, when used as a resin composition for semiconductor sealing filling for a pre-supply system, excellent connection reliability is achieved and generation of voids in the resin at the time of connection is sufficiently suppressed. It is possible to provide an epoxy resin composition for semiconductor sealing filling that can be performed, and a semiconductor device using the same.

1 is a schematic cross-sectional view showing an embodiment of a semiconductor device according to the present invention. In the reference example 3, it is the external appearance observation photograph of a connection part when process temperature is 160 degreeC. In the reference example 3, it is the external appearance observation photograph of the connection part when process temperature is 170 degreeC. 2 is a temperature profile of a temporary fixing process in Example 1. FIG. 2 is a temperature profile of a first step in Example 1. FIG. 2 is a temperature profile of a second step in Example 1. FIG. 3 is an observation image obtained by observing the void state of the semiconductor device of Example 1 with an ultrasonic flaw detector. 2 is a cross-sectional observation photograph of a connection part of Example 1. FIG. It is the temperature profile of the 1st process of Example 5, and a 2nd process. It is the observation image which observed the void situation of the semiconductor device of comparative example 5 with the ultrasonic flaw detector. 10 is a cross-sectional observation photograph of a connection portion of a semiconductor device of Comparative Example 5.

  The epoxy resin composition for semiconductor encapsulation filling of the present invention (hereinafter also simply referred to as “epoxy resin composition”) contains an epoxy resin, a curing agent, and a flux agent as essential components.

  The epoxy resin is not particularly limited as long as it is bifunctional or higher. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type Epoxy resin, hydroquinone type epoxy resin, diphenyl sulfide skeleton containing epoxy resin, phenol aralkyl type polyfunctional epoxy resin, naphthalene skeleton containing polyfunctional epoxy resin, dicyclopentadiene skeleton containing polyfunctional epoxy resin, triphenylmethane skeleton containing polyfunctional epoxy resin Aminophenol type epoxy resin, diaminodiphenylmethane type epoxy resin, and other various polyfunctional epoxy resins can be used. Among these, from the viewpoint of low viscosity, low water absorption, and high heat resistance, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene skeleton-containing polyfunctional epoxy resin, dicyclopentadiene skeleton-containing polyfunctional epoxy resin, tri It is desirable to use a polyfunctional epoxy resin containing a phenylmethane skeleton. The properties of these epoxy resins may be liquid or solid at 25 ° C. Moreover, you may use these epoxy resins individually or in mixture of 2 or more types.

  As the curing agent, for example, imidazoles, acid anhydrides, amines, phenols, hydrazides, polymercaptans, and Lewis acid-amine complexes can be used. Among them, it is desirable to use imidazoles, acid anhydrides, amines and phenols from the viewpoints of low viscosity, storage stability, heat resistance of the cured product, etc., and imidazoles and amines from the viewpoint of moisture resistance reliability. More preferably, phenols are used.

  Examples of imidazoles include 2MZ, C11Z, 2PZ, 2E4MZ, 2P4MZ, 1B2MZ, 1B2PZ, 2MZ-CN, 2E4MZ-CN, 2PZ-CN, C11Z-CN, 2PZ-CNS, C11Z-CNS, 2MZ-A, and C11Z. -A, 2E4MZ-A, 2P4MHZ, 2PHZ, 2MA-OK, 2PZ-OK (manufactured by Shikoku Kasei Kogyo Co., Ltd., product name) and compounds obtained by adding these imidazoles to an epoxy resin can be mentioned. In addition, those encapsulating these hardeners with polyurethane-based or polyester-based polymer materials and making them into microcapsules are preferable because the pot life is extended. These may be used alone or in admixture of two or more.

  It is preferable that the compounding quantity of imidazoles is 0.1 to 10 weight% with respect to an epoxy resin, More preferably, it is 0.5 to 10 weight%, More preferably, it is 1 to 10 weight%. If it is less than 0.1% by weight, it may not be cured sufficiently. If it exceeds 10% by weight, the storage stability may be lowered, or the gelation time may be too fast.

  Examples of acid anhydrides include maleic anhydride, succinic anhydride, dodecenyl succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl Hexahydrophthalic anhydride, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, methyl hymic acid anhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, polyazeline acid anhydride, alkylstyrene Maleic anhydride copolymer, 3,4-dimethyl-6- (2-methyl-1-propenyl) -4-cyclohexene-1,2-dicarboxylic anhydride, 1-isopropyl-4-methyl-bicyclo [ 2.2.2] Oct-5-ene-2,3-dicarboxylic anhydride, ethylene Glycol bis trimellitate and glycerol tris anhydro trimellitate can be used. Among these, in particular, from the viewpoint of heat resistance and moisture resistance, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, 3,4-dimethyl-6 -(2-Methyl-1-propenyl) -4-cyclohexene-1,2-dicarboxylic anhydride, 1-isopropyl-4-methyl-bicyclo [2.2.2] oct-5-ene-2,3- It is desirable to use dicarboxylic anhydride, ethylene glycol bis trimellitate, glycerol tris anhydro trimellitate. These may be used alone or in admixture of two or more.

  The acid anhydrides should be blended so that the ratio of the number of epoxy groups to the number of carboxylic acids generated from the acid anhydride groups (number of epoxy groups / number of carboxylic acids) is 0.5 to 1.5. Is more preferable, and 0.7 to 1.2 is more preferable. If it is less than 0.5, the carboxylic acid groups will remain excessively, and the insulation reliability may be lower than in the above range, and if it is more than 1.5, curing may not proceed sufficiently.

  The amine is not particularly limited as long as it is a compound having at least one primary or secondary amino group in the molecule. From the viewpoint of storage stability and heat resistance of the cured product, aromatic amines may be used. desirable. Examples of aromatic amines include diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl sulfide, metaxylenediamine, 3,3′-diethyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5′-tetraethyl. -4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 2,2-bis- [4- (4-aminophenoxy) phenyl] -hexafluoropropane, 2 , 2-bis (4-aminophenyl) -hexafluoropropane, 2,4-diaminotoluene, 1,4-diaminobenzene, 1,3-diaminobenzene, diethyltoluenediamine, dimethyltoluenediamine, anilines, alkylated anilines N-alkylated anilines Can be used. These may be used alone or in admixture of two or more.

  The amines are desirably blended so that the ratio of the number of epoxy groups to the number of active hydrogens (number of epoxy groups / number of active hydrogens) is 0.5 to 1.5, more preferably 0.7. ~ 1.2. If it is less than 0.5, amines may remain excessively and the moisture resistance reliability may be lowered. If it is more than 1.5, curing may not proceed sufficiently.

  Phenols include bisphenol resin, phenol novolak resin, naphthol novolak resin, allylated phenol novolak resin, biphenol resin, cresol novolak resin, phenol aralkyl resin, cresol naphthol formaldehyde polycondensate, triphenylmethane type polyfunctional phenol resin, xylylene Modified phenol novolac resins, xylylene modified naphthol novolac resins, and various polyfunctional phenol resins can be used. These can be used alone or as a mixture of two or more.

  As the blending amount of phenols, it is desirable that the ratio of the number of epoxy groups and the number of phenolic hydroxyl groups (number of epoxy groups / number of phenolic hydroxyl groups) is 0.5 to 1.5, More preferably, it is 0.7-1.2. If it is smaller than 0.5, phenols may remain excessively and the moisture resistance reliability may be lowered, and if it is larger than 1.5, curing may not proceed sufficiently.

  When acid anhydrides, amines, and phenols are used as a curing agent, a curing accelerator may be used in combination. As the curing accelerator, in addition to the imidazoles, for example, tertiary amines, 1,8-diazabicyclo (5.4.0) undecene-7, 1,5-diazabicyclo (4.3.0) nonene-5, etc. Cyclic amines and their tetraphenylborate salts, trialkylphosphines such as tributylphosphine, triarylphosphines such as triphenylphosphine, tetraphenylphosphonium tetraphenylborate and tetra (n-butyl) phosphonium tetraphenylborate Quaternary phosphonium salts can be used. The blending amount is appropriately set in consideration of gelation time and storage stability.

  Content of the hardening | curing agent in an epoxy resin composition can be 1-70 mass parts with respect to 100 mass parts of epoxy resins, for example.

  As the fluxing agent, it is desirable to use at least one compound selected from alcohols, phenols, and carboxylic acids.

  The alcohol is not particularly limited as long as it is a compound having at least two alcoholic hydroxyl groups in the molecule. For example, 1,3-dioxane-5,5-dimethanol, 1,5-pentanediol, 2 , 5-furandiethanol, diethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, 1,2,3-hexanetriol, 1,2,4-butanetriol, 1,2,6-hexanetriol, 3-methyl Pentane-1,3,5-triol, glycerin, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol, ribitol, sorbitol, 2,4-diethyl-1,5-pentanediol, propylene glycol monomethyl ether, propylene group Cole monoethyl ether, 1,3-butylene glycol, 2-ethyl-1,3-hexanediol, N-butyldiethanolamine, N-ethyldiethanolamine, diethanolamine, triethanolamine, N, N-bis (2-hydroxyethyl) Isopropanolamine, bis (2-hydroxymethyl) iminotris (hydroxymethyl) methane, N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, 1,1 ′, 1 ″, 1 ′ ″ − (Ethylenedinitrilo) tetrakis (2-propanol) can be used. Among them, compounds having a tertiary nitrogen atom such as N-butyldiethanolamine, N-ethyldiethanolamine, triethanolamine, N, N-bis (2-hydroxyethyl) isopropanolamine, bis (2-hydroxymethyl) iminotris (hydroxy) Methyl) methane, N, N, N ′, N′-tetrakis (2-hydroxyethyl) ethylenediamine, 1,1 ′, 1 ″, 1 ′ ″-(ethylenedinitrilo) tetrakis (2-propanol) Compared with other compounds, it is desirable because it exhibits a good flux activity. Although the detailed reason for showing good flux activity is not clear, the ability to reduce oxide film by alcoholic hydroxyl group and the ability to reduce by electron donating property derived from unpaired electrons on the tertiary nitrogen atom act together. It is presumed to be caused. These compounds may be used alone or in combination of two or more.

The phenol is not particularly limited as long as it is a compound having at least two phenolic hydroxyl groups. For example, catechol, resorcinol, hydroquinone, biphenol, dihydroxynaphthalene, hydroxyhydroquinone, pyrogallol, methylidene biphenol (bisphenol F), Examples include isopropylidene biphenol (bisphenol A), ethylidene biphenol (bisphenol AD), 1,1,1-tris (4-hydroxyphenyl) ethane, trihydroxybenzophenone, trihydroxyacetophenone, and poly p-vinylphenol.
Further, as a compound having at least two phenolic hydroxyl groups, at least one compound selected from compounds having at least one phenolic hydroxyl group in the molecule and a halomethyl group, alkoxymethyl group or hydroxylmethyl group are molecules. A polycondensation product with at least one compound selected from the group consisting of two aromatic compounds, divinylbenzene and aldehydes can also be used. Examples of the compound having at least one phenolic hydroxyl group in the molecule include phenol, alkylphenol, naphthol, cresol, catechol, resorcinol, hydroquinone, biphenol, dihydroxynaphthalene, hydroxyhydroquinone, pyrogallol, methylidene biphenol (bisphenol F), Examples include isopropylidene biphenol (bisphenol A), ethylidene biphenol (bisphenol AD), 1,1,1-tris (4-hydroxyphenyl) ethane, trihydroxybenzophenone, trihydroxyacetophenone, and poly p-vinylphenol. Moreover, as the aromatic compound having two romethyl group, alkoxymethyl group or hydroxylmethyl group in the molecule, for example, 1,2-bis (chloromethyl) benzene, 1,3-bis (chloromethyl) benzene, 1,4-bis (chloromethyl) benzene, 1,2-bis (methoxymethyl) benzene, 1,3-bis (methoxymethyl) benzene, 1,4-bis (methoxymethyl) benzene, 1,2-bis ( Hydroxymethyl) benzene, 1,3-bis (hydroxymethyl) benzene, 1,4-bis (hydroxymethyl) benzene, bis (chloromethyl) biphenyl, bis (methoxymethyl) biphenyl. Examples of aldehydes include formaldehyde (formalin as an aqueous solution thereof), paraformaldehyde, trioxane, and hexamethylenetetramine.
Examples of the polycondensate include a phenol novolac resin that is a polycondensate of phenol and formaldehyde, a cresol novolac resin that is a polycondensate of cresol and formaldehyde, a naphthol novolac resin that is a polycondensate of naphthols and formaldehyde, Phenol aralkyl resin, which is a polycondensation product of phenol and 1,4-bis (methoxymethyl) benzene, polycondensation product of bisphenol A and formaldehyde, polycondensation product of phenol and divinylbenzene, polycondensation of cresol, naphthol and formaldehyde These may be those obtained by rubber modification of these polycondensates or those obtained by introducing an aminotriazine skeleton or dicyclopentadiene skeleton into the molecular skeleton. Furthermore, examples of the compounds that have been liquefied by allylating these compounds having a phenolic hydroxyl group include allylated phenol novolac resins, diallyl bisphenol A, diallyl bisphenol F, diallyl biphenol, and the like. These compounds may be used alone or in combination of two or more.

  The carboxylic acids may be either aliphatic carboxylic acids or aromatic carboxylic acids. Examples of the aliphatic carboxylic acid include malonic acid, methylmalonic acid, dimethylmalonic acid, ethylmalonic acid, allylmalonic acid, 2,2′-thiodiacetic acid, 3.3′-thiodipropionic acid, 2,2′- (Ethylenedithio) diacetic acid, 3,3′-dithiodipropionic acid, 2-ethyl-2-hydroxybutyric acid, dithiodiglycolic acid, diglycolic acid, acetylenedicarboxylic acid, maleic acid, malic acid, 2-isopropylmalic acid , Tartaric acid, itaconic acid, 1,3-acetone dicarboxylic acid, tricarbaric acid, muconic acid, β-hydromuconic acid, succinic acid, methyl succinic acid, dimethyl succinic acid, glutaric acid, α-ketoglutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,2-dimethylglutaric acid, 3,3-dimethylglutaric acid, 2,2-bis (hydroxymethyl) ) Propionic acid, citric acid, adipic acid, 3-tert-butyladipic acid, pimelic acid, phenyloxalic acid, phenylacetic acid, nitrophenylacetic acid, phenoxyacetic acid, nitrophenoxyacetic acid, phenylthioacetic acid, hydroxyphenylacetic acid, dihydroxyphenylacetic acid, Mandelic acid, hydroxymandelic acid, dihydroxymandelic acid, 1,2,3,4-butanetetracarboxylic acid, suberic acid, 4,4'-dithiodibutyric acid, cinnamic acid, nitrocinnamic acid, hydroxycinnamic acid, dihydroxy Cinnamic acid, coumaric acid, phenylpyruvic acid, hydroxyphenylpyruvic acid, caffeic acid, homophthalic acid, tolylacetic acid, phenoxypropionic acid, hydroxyphenylpropionic acid, benzyloxyacetic acid, phenyllactic acid, tropic acid, 3- (phenylsulfonyl) Propionic acid, 3,3-tetramethylene glutaric acid, 5-oxoazelaic acid, azelaic acid, phenylsuccinic acid, 1,2-phenylenediacetic acid, 1,3-phenylenediacetic acid, 1,4-phenylenediacetic acid, benzyl Malonic acid, sebacic acid, dodecanedioic acid, undecanedioic acid, diphenylacetic acid, benzylic acid, dicyclohexylacetic acid, tetradecanedioic acid, 2,2-diphenylpropionic acid, 3,3-diphenylpropionic acid, 4,4-bis (4 -Hydroxyphenyl) valeric acid, pimaric acid, parastrinic acid, isopimaric acid, abietic acid, dehydroabietic acid, neoabietic acid, agatic acid. Examples of the aromatic carboxylic acid include benzoic acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5- Dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 2,3,4-trihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid, 3,4,5-trihydroxy Benzoic acid, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2- [bis (4-hydroxyphenyl) methyl] benzoic acid, 1- Naphthoic acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-1-naphthoic acid, 3-hydroxy-2-naphthoic acid, 6- Droxy-2-naphthoic acid, 1,4-dihydroxy-2-naphthoic acid, 3,5-dihydroxy-2-naphthoic acid, 3,7-dihydroxy-2-naphthoic acid, 2,3-naphthalenedicarboxylic acid, 2, Examples include 6-naphthalenedicarboxylic acid, 2-phenoxybenzoic acid, biphenyl-4-carboxylic acid, biphenyl-2-carboxylic acid, and 2-benzoylbenzoic acid. Among these, from the viewpoint of storage stability and availability, succinic acid, malic acid, itaconic acid, 2,2-bis (hydroxymethyl) propionic acid, adipic acid, 3,3′-thiodipropionic acid, 3 , 3′-dithiodipropionic acid, 1,2,3,4-butanetetracarboxylic acid, suberic acid, sebacic acid, phenylsuccinic acid, dodecanedioic acid, diphenylacetic acid, benzylic acid, 4,4-bis (4- Hydroxyphenyl) valeric acid, abietic acid, 2,5-dihydroxybenzoic acid, 3,4,5-trihydroxybenzoic acid, 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2- It is desirable to use [bis (4-hydroxyphenyl) methyl] benzoic acid. These compounds may be used alone or in combination of two or more.

  Further, the fluxing agent may be liquid or solid at room temperature, but it is desirable to use a solid compound at room temperature from the viewpoint of storage stability.

  Content of the flux agent in an epoxy resin composition can be 1-10 mass parts with respect to 100 mass parts of epoxy resins, for example.

  The epoxy resin composition may contain an inorganic filler in order to reduce the thermal expansion coefficient and improve the connection reliability. Examples of the inorganic filler include glass, silicon dioxide (silica), aluminum oxide (alumina), titanium oxide (titania), magnesium oxide (magnesia), carbon black, mica, and barium sulfate. You may use these individually or in mixture of 2 or more types. In addition, a composite oxide containing two or more types of metal oxides (not just a mixture of two or more types of metal oxides, but the metal oxides are chemically bonded to each other and cannot be separated) For example, a composite oxide composed of silicon dioxide and titanium oxide, silicon dioxide and aluminum oxide, boron oxide and aluminum oxide, silicon dioxide, aluminum oxide and magnesium oxide.

  The shape of the inorganic filler is not particularly limited to a crushed shape, a needle shape, a flake shape, and a spherical shape, but a spherical shape is preferably used from the viewpoint of dispersibility and viscosity control. Moreover, the size of the filler is not particularly limited as long as the average particle size is smaller than the gap between the semiconductor chip and the substrate when the flip chip connection is made, but from the viewpoint of packing density and viscosity control, the average particle size is 10 μm or less. Those having a thickness of 5 μm or less are more preferable, those having a thickness of 3 μm or less are particularly preferable. Furthermore, in order to adjust the viscosity and the physical properties of the cured product, two or more types having different particle sizes may be used in combination.

  Content of the inorganic filler in an epoxy resin composition can be 0-200 mass parts with respect to 100 mass parts of epoxy resins, for example.

  The epoxy resin composition of the present embodiment may be in the form of a paste or a film at room temperature, but is preferably a film from the viewpoint of handleability.

  The epoxy resin composition of the present embodiment may contain a thermoplastic resin in order to form a film. Examples of the thermoplastic resin include phenoxy resin, polyimide resin, polyamide resin, polycarbodiimide resin, phenol resin, cyanate ester resin, acrylic resin, polyester resin, polyethylene resin, polyethersulfone resin, polyetherimide resin, polyvinyl acetal resin, Polyvinyl butyral resin, urethane resin, polyurethane imide resin, and acrylic rubber are listed. Among them, phenoxy resin, polyimide resin, polyvinyl butyral resin, polyurethane imide resin, and acrylic rubber, which are excellent in heat resistance and film formability, are desirable. Phenoxy resin, polyimide A resin is more preferable. The weight average molecular weight of the thermoplastic resin is desirably larger than 5000, more desirably 10,000 or more, further desirably 20000 or more, and in the case of 5000 or less, the film forming ability may be lowered. The weight average molecular weight is a value measured in terms of polystyrene using GPC (Gel Permeation Chromatography). Moreover, these thermoplastic resins can be used alone or as a mixture or copolymer of two or more.

  Content of the thermoplastic resin in an epoxy resin composition can be 0-100 mass parts with respect to 100 mass parts of epoxy resins, for example.

  In the epoxy resin composition of the present embodiment, after the epoxy resin composition is supplied to the bump forming surface of the semiconductor chip or the electrode surface of the substrate, the temperature is higher than the activation temperature of the flux agent and lower than the melting point or softening point of the solder or tin. A plurality of bumps by a connection method comprising a first step of pressing the semiconductor chip against the substrate, and a second step of heating the semiconductor chip bumps and electrodes by metal bonding, so as to be equal to or higher than the melting point of solder or tin. And a substrate having a plurality of electrodes (provided that tin or solder is present on at least one surface of the bump and the electrode).

  The first step aims to eliminate the resin from between the bump and the electrode, and reduce and remove the oxide film on the surface of the solder or tin with a flux agent. The heating temperature in the first step is set to a temperature higher than the melting point or softening point of the fluxing agent and lower than the melting point of solder or tin. By setting the temperature in this way, the resin whose viscosity has been reduced by heating is excluded from between the bump and the electrode, and the solder or tin oxide film on the bump or electrode is removed. Furthermore, since the bumps or electrodes are covered with the epoxy resin composition, reoxidation can be prevented. Further, since the temperature does not reach the melting point of solder or tin, the connection portion cannot be formed by metal bonding.

  In addition, when a solid fluxing agent is used at room temperature, in order to show the flux activity, it is necessary to be in a liquid or low viscosity state at a temperature equal to or higher than its melting point and softening point, and to uniformly wet the surface of solder or tin. Therefore, the lower limit of the heating temperature in the first step is the melting point or softening point of the solid flux agent. Furthermore, if the melting point or softening point of the solid fluxing agent is higher than the melting point of the solder or tin, the oxide film on the surface of the solder or tin is removed and the solder or tin is melted. Since trapping in which the composition or filler is taken in may occur, the melting point and softening point of the solid fluxing agent are preferably lower than the melting point of solder or tin. Also, by performing the first step, the reaction between the epoxy resin and the curing agent partially starts and the low molecular weight component has become high molecular weight, and is generated by the volatilization of the low molecular weight component under the high temperature connection condition in the second step. The effect of suppressing voids is expected.

  As the load when pressing the semiconductor chip against the substrate in the first step, the load necessary to eliminate the resin from between the bump and the electrode is appropriately set according to the area of the semiconductor chip and the number of bumps. In order to prevent damage such as cracks from occurring, it is desirable that the pressure is 2 MPa or less, more desirably 1.5 MPa or less, and 1 MPa or less. More desirable. Further, it is preferably 0.5 N or less per bump, more preferably 0.2 N or less, and further preferably 0.1 N or less.

  The gelation time of the epoxy resin composition at the heating temperature in the first step is longer than the heating time in the first step. If the gelation time of the epoxy resin composition is equal to or shorter than the heating time of the first step, the resin hardens before the bumps reach the electrode, resulting in poor connection or the viscosity of the resin in the second step. As a result, the solder or tin that is melted does not sufficiently wet the bumps or electrodes, and connection failure may occur. From the viewpoint of productivity, the heating time of the first step is desirably 20 seconds or less, more desirably 15 seconds or less, and further desirably 10 seconds or less.

  The purpose of the second step is to melt the solder and tin to bond the bump and the electrode to each other. The heating temperature in the second step is set to a temperature equal to or higher than the melting point of solder or tin. The upper limit of the heating temperature in the second step is not particularly limited, but can be set to, for example, 300 ° C. in consideration of minimizing damage to the semiconductor chip and the substrate. Since the removal of the oxide film on the surface of the solder or tin and the resin removal between the bump and the electrode are completed in the first step, the solder and tin are quickly melted to exhibit good wettability on the electrode and bump surface. In addition, trapping can be suppressed.

  The second step may be performed without pressing the semiconductor chip and the substrate, but the semiconductor chip and the substrate may be pressed so that the semiconductor chip is lifted by the thermal expansion of the sealing resin and no connection failure occurs. desirable. The load when pressing the semiconductor chip against the substrate in the second step is desirably a pressure of 2 MPa or less with respect to the area of the semiconductor chip so that the semiconductor chip is not damaged as in the first step. More preferably, the pressure is 1.5 MPa or less, and more preferably 1 MPa or less. Further, it is preferably 0.5 N or less per bump, more preferably 0.2 N or less, and further preferably 0.1 N or less.

  The gelation time of the epoxy resin composition at the heating temperature in the second step is equal to or shorter than the heating time in the second step. As a result, the gelled epoxy resin composition reinforces the connection part by metal bonding, and in the cooling process after the connection is completed, thermal stress caused by the difference in thermal expansion coefficient between the semiconductor chip and the substrate is concentrated on the connection part by metal bonding. Thus, an effect of suppressing connection failures such as cracks generated is expected. When the gelation time of the epoxy resin composition is longer than the heating time of the second step, the curing reaction does not proceed sufficiently, and the low molecular weight component may volatilize and voids may be generated. From the viewpoint of productivity, the heating time in the second step is desirably 20 seconds or less, more desirably 15 seconds or less, and further desirably 10 seconds or less.

  The first step and the second step may be performed continuously with a single connection device, but the connection device needs to be heated or cooled, resulting in a longer work time and lower productivity. There is a case. On the other hand, by separating the first step and the second step and performing them separately with different connecting devices, it becomes possible to work while keeping the set temperature of the connecting device constant, and high productivity can be realized. In addition, it is possible to simplify equipment by using a connection device equipped with a mechanism (constant heat mechanism) that can be heated to a constant temperature, rather than a connection device equipped with a temperature rise and cooling mechanism (pulse heat mechanism). It becomes.

  Furthermore, when performing the first step, the semiconductor chip and the substrate may be aligned, but before the first step, after the semiconductor chip and the substrate are aligned, the temperature is lower than the activation temperature of the fluxing agent. You may perform the process of temporarily fixing a semiconductor chip to a board | substrate in temperature and the temperature which an epoxy resin composition shows adhesiveness. By providing such a temporary fixing step, it is possible to perform the first step and the second step for a plurality of semiconductor chips and substrates in a lump, thereby realizing high productivity.

  After performing the second step, heat treatment may be performed using a heating oven or the like as necessary in order to advance the curing of the epoxy resin composition.

  The epoxy resin composition in a paste form at room temperature can be supplied to a semiconductor chip or a substrate by dispensing or printing, and the epoxy resin composition in a film form at room temperature is cut into a predetermined size as a semiconductor chip. Alternatively, it can be supplied by attaching it to a semiconductor chip or a substrate.

  Furthermore, after the epoxy resin composition layer is formed on the bump forming surface of the semiconductor wafer, it is possible to supply the epoxy resin composition to the bump forming surface of the semiconductor chip by dividing into individual semiconductor chips. . By this method, a plurality of semiconductor chips to which the epoxy resin composition is supplied can be produced at a time, so that improvement in productivity is expected.

  As a method for forming the epoxy resin composition layer on the bump forming surface of the semiconductor wafer, a paste-like material can be applied by spin coating or printing, and a film-like material can be laminated. From the viewpoint of workability, a method of laminating a film is desirable. In order to laminate the film-like epoxy resin composition on the bump forming surface of the semiconductor wafer, a hot roll laminator or a vacuum laminator can be used.

  When an epoxy resin composition layer is formed on the bump forming surface of a semiconductor wafer, the epoxy resin composition is transparent to recognize through the epoxy resin composition layer a reference mark for alignment at the time of dicing line and connection. It is desirable to have a transmittance of 10% or more for visible light of 555 nm.

  Furthermore, in order to prevent trapping in which the epoxy resin composition is taken in between the bump and the electrode, a method of forming the epoxy resin composition layer so that the bump tip is exposed from the epoxy resin composition layer has been proposed. However, in the present invention, in the first process, the removal of the surface oxide film of solder and tin and the resin removal from between the bump and the electrode are completed in the first process, and in the second process. Since the solder and tin are melted and metal-bonded, trapping that occurs as the solder and tin are melted is unlikely to occur, and therefore it is not necessary to expose the bump tip from the epoxy resin composition layer.

  Examples of a method for dividing a semiconductor wafer having an epoxy resin composition layer formed on a bump forming surface into semiconductor chips include blade dicing, laser dicing, and stealth dicing. Also, a semiconductor wafer having an epoxy resin composition layer formed on the bump forming surface may be fixed to a dicing device by bonding the surface opposite to the bump forming surface of the semiconductor wafer to a dicing tape, or an epoxy resin composition The material layer may be bonded to the dicing tape and fixed to the dicing apparatus.

  Further, as the semiconductor wafer, a semiconductor wafer that has been thinned in advance to a predetermined thickness by back grinding may be used, or an epoxy resin composition layer is formed on the bump forming surface of the semiconductor wafer before back grinding. The back grind tape may be bonded so as to be in contact with the epoxy resin composition layer, and the semiconductor wafer may be thinned to a predetermined thickness by back grinding from the surface opposite to the bump forming surface. Furthermore, after forming grooves by half-cutting with a dicing machine along the dicing line of the semiconductor wafer before back grinding, an epoxy resin composition layer is formed on the bump forming surface, and the back grinding tape is made of epoxy resin composition The semiconductor wafer may be thinned and separated into semiconductor chips while the groove is exposed by back grinding from the surface opposite to the bump forming surface by bonding so as to be in contact with the physical layer.

  As an apparatus for connecting the semiconductor chip and the substrate, a normal flip chip bonder can be used. Also, a flip chip bonder is used to align the semiconductor chip and the substrate and temporarily fix the semiconductor chip to the substrate, and the first and second steps are performed by a thermocompression bonding apparatus equipped with a pressure and heating mechanism. May be.

  The semiconductor chip used in the present invention is not particularly limited, and various semiconductors such as elemental semiconductors such as silicon and germanium, and compound semiconductors such as gallium arsenide and indium phosphide can be used.

  As bumps formed on the semiconductor chip, for example, solder bumps, copper bumps, bumps having a structure in which a solder or tin layer is formed on the tip of a copper pillar, or gold bumps can be used. As the solder, Sn-37Pb (melting point 183 ° C.) may be used, but considering the influence on the environment, Sn-3.5Ag (melting point 221 ° C.), Sn-2.5Ag-0.5Cu-1Bi ( It is desirable to use lead-free solder such as Sn-0.7Cu (melting point 227 ° C), Sn-3Ag-0.5Cu (melting point 217 ° C), Sn-92Zn (melting point 198 ° C). In addition, from the viewpoint of coping with fine connection, a copper bump or a bump having a structure in which a solder or tin layer is formed on the tip of the copper pillar is suitable.

  The substrate may be a normal circuit board or a semiconductor chip. In the case of a circuit board, a wiring pattern (electrode) is formed by etching away unnecessary portions of a metal layer such as copper formed on the surface of an insulating board such as glass epoxy, polyimide, polyester, ceramic, etc. A wiring pattern formed by copper plating or the like, or a wiring pattern formed by printing a conductive material on the surface of an insulating substrate can be used.

  It is desirable that one type of surface treatment layer selected from a gold layer, a solder layer, a tin layer, and a rust preventive film layer is formed on the surface of the wiring pattern. The gold layer and the tin layer can be formed by electroless or electrolytic plating. The solder layer may be formed by plating, or may be formed by a method in which a solder paste is applied by printing and then heated and melted, or a method in which fine solder particles are placed on a wiring pattern and heated and melted. The anticorrosive film layer, also called preflux, removes the oxide film on the surface of the wiring pattern made of copper, etc. by immersing the substrate in a special chemical solution, and also has an antirust film made of organic components on the surface. This is preferable because it is possible to ensure good wettability with respect to solder and tin and to cope with fine connection. When the bump formed on the semiconductor chip is a gold bump, it is essential that a solder layer or a tin layer is formed in order to form a metal joint.

  Next, a semiconductor device manufactured using the epoxy resin composition of the present invention will be described.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of a semiconductor device according to the present invention. A semiconductor device 10 shown in FIG. 1 includes a circuit board 7, a semiconductor chip 5, and a sealing resin 6 disposed between the circuit board 7 and the semiconductor chip 5. The sealing resin 6 is made of a cured product of the resin composition for semiconductor sealing filling of the present invention and seals the gap between the circuit board 7 and the semiconductor chip 5. The circuit board 7 includes a board such as an interposer and wiring 4 provided on one surface of the board. The wiring (electrode) 4 of the circuit board 7 and the semiconductor chip 5 are electrically connected by a plurality of bumps 3 provided on the semiconductor chip 5. The circuit board 7 has an electrode pad 2 and a solder ball 1 provided on the electrode pad 2 on the surface opposite to the surface on which the wiring 4 is provided, and is connected to other circuit members. Is possible.

  As a semiconductor device manufactured using the epoxy resin composition of the present invention, a CSP (chip size package) or BGA (ball grid array) having a structure in which a semiconductor chip is mounted on a substrate called an interposer, Examples include CoC (chip on chip) having a structure in which another semiconductor chip is mounted thereon, and 3D package having a structure in which a plurality of semiconductor chips are three-dimensionally stacked by through electrodes.

(Reference example)
(Activation temperature evaluation of flux agent)
The activation temperature of the fluxing agent was evaluated by the following procedure. All operations were performed in a glove box substituted with nitrogen.
A flux agent and solder balls (Sn-3Ag-0.5Cu, diameter 0.4 mm, melting point 217 ° C.) are mixed in a crucible, heated at a predetermined processing temperature for 30 seconds, and then ultrasonically washed with methanol three times. It was. The remaining solder balls were placed on a copper foil and placed on a hot plate at 250 ° C. for 30 seconds to observe the appearance of the solder. The processing temperature at which wetting of the copper foil and fusion of the solder balls was observed was defined as the temperature showing the flux activity. The results are shown in Table 1.

  FIG. 2 is an appearance observation photograph of the connection portion when the processing temperature is 160 ° C. in Reference Example 3. FIG. 3 is an appearance observation photograph of the connection portion when the processing temperature is 170 ° C. in Reference Example 3. It is a photograph. As is clear from these figures, when the treatment temperature is set to a temperature lower than the melting point of the flux agent (160 ° C.), wetting to the copper foil and fusion between the solder balls are not observed, When the processing temperature is set to a temperature equal to or higher than the melting point of the fluxing agent (170 ° C.), a solder fusion part where the solder balls are fused is observed.

[Examples 1-4, Comparative Examples 1-3]
The components shown in Table 2 were dissolved and mixed in a toluene-ethyl acetate solvent to prepare a varnish, and this varnish was applied onto a separator film (PET film) using a knife coater. This was dried in an oven at 70 ° C. or 110 ° C. for 10 minutes to produce a film-like epoxy resin composition having a thickness of 25 μm.

(raw materials)
Phenoxy resin 1: ε-caprolactone-modified phenoxy resin PKCP80 (product name, manufactured by Inchem Corporation)
Phenoxy resin 2: Bisphenol A type phenoxy resin YP50S (product name, manufactured by Tohto Kasei Co., Ltd.)
Epoxy resin 1: Trisphenol methane type polyfunctional epoxy EP1032H60 (product name, manufactured by Japan Epoxy Resin Co., Ltd.)
Epoxy resin 2: Bis F type liquid epoxy YL983U (product name, manufactured by Japan Epoxy Resin Co., Ltd.)
Epoxy resin 3: flexible liquid epoxy YL7175-1000 (product name, manufactured by Japan Epoxy Resin Co., Ltd.)
Curing agent 1: Liquid acid anhydride YH307 (Japan Epoxy Resin Co., Ltd., product name)
Curing agent 2: 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid adduct 2MAOK-PW (product name, manufactured by Shikoku Kasei Kogyo Co., Ltd.)
Curing agent 3: 2-phenyl-4,5-dihydroxymethylimidazole 2PHZ-PW (manufactured by Shikoku Kasei Kogyo Co., Ltd., product name)
Curing accelerator: Tetraphenylphosphonium tetraphenylborate TPP-K (product name, manufactured by Hokuko Chemical Co., Ltd.)
Flux agent 1: Adipic acid (manufactured by Sigma-Aldrich, product name)
Flux agent 2: 4,4-bis (4-hydroxyphenyl) valeric acid (product name, manufactured by Sigma-Aldrich)
Filler: Silica Filler SE2050 (manufactured by Admatechs, product name)

(Measurement of gelation time)
The film-like epoxy resin composition from which the separator was peeled off was placed on a hot plate at 180 ° C. and 250 ° C., and the time until stirring became impossible with a spatula was defined as the gel time.

(Connection between semiconductor chip and substrate)
As a semiconductor chip in which a bump having a structure having a lead-free solder layer (Sn-3.5Ag: melting point 221 ° C.) is formed at the tip of the copper pillar, JTEG PHASE11_80 (size 7.3 mm × 7.3 mm, bump made by Hitachi ULSI Systems) A glass epoxy substrate having a pitch of 80 μm, a number of bumps of 328, a thickness of 0.55 mm, a trade name), and a copper wiring pattern having a rust-preventive film formed by preflux treatment on the surface was prepared. Subsequently, the film-like epoxy resin composition was cut out to 9 mm × 9 mm, adhered to a region on the substrate where the semiconductor chip was mounted under the condition of 80 ° C./0.5 MPa / 5 seconds, and then the separator film was peeled off. The substrate on which the film-like epoxy resin composition is affixed is adsorbed and fixed onto a stage set to 40 ° C. of a flip chip bonder FCB3 (manufactured by Panasonic Factory Solutions), aligned with the semiconductor chip, and then temporarily fixed. As a process, pressure bonding was performed for 5 seconds at a load of 25 N and a head temperature of 100 ° C. (reaching 90 ° C.), and the semiconductor chip was temporarily fixed on the substrate. Next, as the first step, the head temperature of the flip chip bonder is set to 210 ° C. in advance so that the temperature of the connecting portion is 180 ° C. higher than the melting point of the solid fluxing agent and lower than the melting point of the lead-free solder. Crimping was performed for 10 seconds. Next, as a second step, the head temperature of the flip chip bonder was set to 290 ° C. in advance so that the temperature of the connecting portion was 250 ° C. higher than the melting point of lead-free solder, and pressure bonding was performed at a load of 25 N for 10 seconds. The temperature of the connection portion was measured by separately manufacturing a K-type thermocouple sandwiched between the semiconductor chip and the substrate.

  In addition, the temperature profile of the temporary fixing process in Example 1 is shown in FIG. 4, the temperature profile of the first process in Example 1 is shown in FIG. 5, and the temperature profile of the second process in Example 1 is shown in FIG.

(Continuity test)
The semiconductor device in which the semiconductor chip and the substrate were connected was evaluated as a pass (◯) if the 328 bump daisy chain connection could be confirmed, and as a fail (x) if the daisy chain connection could not be confirmed. The results are shown in Table 3.

(Void evaluation)
A semiconductor device in which a semiconductor chip and a substrate are connected is observed with an ultrasonic flaw detector (FineSAT, manufactured by Hitachi Construction Machinery Co., Ltd.). On the other hand, the case where the area occupied by the voids exceeded 1% was regarded as rejected (x). The results are shown in Table 3.
An observation image obtained by observing the void state of the semiconductor device of Example 1 with an ultrasonic flaw detector is shown in FIG. As is apparent from this figure, in the semiconductor device of Example 1, almost no voids are observed.

(Connection status evaluation)
The connection part of the semiconductor device in which the semiconductor chip and the substrate were connected was exposed by polishing the cross section and observed with an optical microscope. The trapping was not observed in the connection portion, and the solder was sufficiently wetted with the wiring was evaluated as pass (◯), and the others were evaluated as reject (x). The results are shown in Table 3.
In addition, the cross-sectional observation photograph of the connection part of Example 1 is shown in FIG. As is apparent from this figure, no trapping is observed in the connection portion of Example 1, and the solder is sufficiently wetted with the wiring.

  When the heating temperature in the first step is set to 180 ° C. which is higher than the melting point of the solid fluxing agent and lower than the melting point of the solder, and the heating temperature in the second step is set to 250 ° C. which is higher than the melting point of the solder, the gelation time at 180 ° C. In Examples 1 to 4, which is longer than the heating time of the first step and the gelation time at 250 ° C. is shorter than the heating time of the second step, there are few voids and it is possible to form a good connection portion. I understand. On the other hand, in the comparative example 1 which does not contain a flux agent, although a void condition is favorable, a favorable connection part cannot be formed. In Comparative Example 2 in which the gelation time at 250 ° C. is longer than the heating time in the second step, voids frequently occur. In Comparative Example 3 in which the gelation time at 180 ° C. is shorter than the heating time in the first step, although there are few voids, a good connection cannot be formed.

[Example 5]
Using the film-like epoxy resin composition of Example 1, the head temperature of the flip chip bonder was changed from the heating temperature of 180 ° C. in the first step to the heating in the second step while maintaining the pressurized state in the first step. The temperature was raised to 250 ° C., and the semiconductor chip and the substrate were connected.
In addition, the temperature profile of the 1st process of Example 5 and a 2nd process is shown in FIG.

[Example 6]
Using the film-like epoxy resin composition of Example 1, the head temperature of the flip chip bonder was set so that the heating temperature in the first step was 160 ° C. (setting 181 ° C.) to connect the semiconductor chip and the substrate. went.

[Comparative Example 4]
Using the film-like epoxy resin composition of Example 1, the head temperature of the flip chip bonder was set so that the heating temperature in the first step would be 120 ° C. (setting 135 ° C.) to connect the semiconductor chip and the substrate. went.

[Comparative Example 5]
After temporarily fixing to the semiconductor chip and the substrate using the film-like epoxy resin composition of Example 1, the semiconductor chip and the substrate were connected only in the second step without performing the first step.

Table 4 shows the results of evaluation similar to the above for the semiconductor devices of Examples 5 and 6 and Comparative Examples 4 and 5.
An observation image obtained by observing the void state of the semiconductor device of Comparative Example 5 with an ultrasonic flaw detector is shown in FIG. 10, and a cross-sectional observation photograph of the connection portion of the semiconductor device of Comparative Example 5 is shown in FIG. As is clear from these drawings, in the semiconductor device of Comparative Example 5, voids increase and lapping is observed at the connection portion.

  From the results of Example 5, it can be seen that good connection is possible even if the first step and the second step are performed successively. In Example 6, since the heating temperature of the first step is higher than the melting point of adipic acid of the solid flux agent, good connection is possible, but the comparative example in which the heating temperature of the first step is connected at a temperature lower than the melting point. 4 cannot form a good connection. Moreover, in the comparative example 5 which connected only by the 2nd process, without performing a 1st process, a void increases and a favorable connection part cannot be formed.

  DESCRIPTION OF SYMBOLS 1 ... Solder ball, 2 ... Electrode pad, 3 ... Bump, 4 ... Wiring, 5 ... Semiconductor chip, 6 ... Sealing resin, 7 ... Circuit board, 10 ... Semiconductor device.

Claims (4)

Used to electrically connect a semiconductor chip having a plurality of bumps and a substrate having a plurality of electrodes (however, tin or solder exists on at least one surface of the bumps and the electrodes). An epoxy resin composition for semiconductor sealing filling,
The epoxy resin composition includes an epoxy resin, a curing agent, and a flux agent as essential components,
In the connection, after the epoxy resin composition is supplied to the bump forming surface of the semiconductor chip or the electrode surface of the substrate, the semiconductor is heated at a temperature higher than the melting point or softening point of the flux agent and lower than the melting point of solder or tin. The first step of pressing the chip against the substrate, and heating is performed to be equal to or higher than the melting point of solder or tin, and is implemented by a connection method including a second step of connecting the bump and the electrode by metal bonding,
The gelation time of the epoxy resin composition at the heating temperature of the first step is longer than the heating time of the first step, and the gelation time of the epoxy resin composition at the heating temperature of the second step is The epoxy resin composition for semiconductor sealing filling which is below the heating time of a 2nd process.   The epoxy resin composition for semiconductor sealing filling according to claim 1, wherein the flux agent is solid at room temperature, and the melting point of the flux agent is lower than the melting point of solder or tin.   The epoxy resin composition for semiconductor sealing filling of Claim 1 or 2 currently formed in the film form.   A semiconductor chip on which a plurality of bumps are formed, a substrate having a plurality of electrodes electrically connected to the bumps (provided that tin or solder is present on at least one surface of the bumps and the electrodes), A semiconductor device comprising: a sealing resin which is made of a cured product of the epoxy resin composition for semiconductor sealing filling according to any one of Items 1 to 3, and seals a gap between the semiconductor chip and the substrate. .