WO2015122115A1

WO2015122115A1 - Production method for semiconductor packages

Info

Publication number: WO2015122115A1
Application number: PCT/JP2015/000118
Authority: WO
Inventors: 寛人江夏; ゆい小澤
Original assignee: 昭和電工株式会社
Priority date: 2014-02-12
Filing date: 2015-01-13
Publication date: 2015-08-20
Also published as: JPWO2015122115A1; TW201542730A

Abstract

Provided is a production method for semiconductor packages whereby a semiconductor package can be produced that: maintains coating properties; is capable of suppressing bleeding after coating by B-staging; is capable of obtaining sufficient adhesiveness even without heating during die-bonding; and has high reliability. A die-attach paste for semiconductors, that includes a photopolymerization initiator (1), a thermal radical generator (2), a polyolefin structure-containing resin (3), and a radical polymerizable compound (4), is coated on a support member and B-staged by irradiating ultraviolet light on the coated die-attach paste for semiconductors. Then a die is arranged and pressure-bonded upon the B-staged die-attach paste for semiconductors, the die and the support member are joined, and die-bonding is performed.

Description

Manufacturing method of semiconductor package

The present invention relates to a semiconductor package manufacturing method using a semiconductor die attach paste.

As a bonding material for manufacturing a semiconductor package by bonding a semiconductor chip such as an IC or LSI (hereinafter referred to as “die”) and a support member such as a lead frame or an insulating support substrate, and sealing them, Au—Si In addition to eutectic alloys and solder, pastes, films, and the like that are mainly made of resin are conventionally known.
The Au—Si eutectic alloy has high heat resistance and high moisture resistance, but has a large elastic modulus, and therefore is easily cracked by the stress of expansion and contraction of other members due to thermal history, and is expensive. Solder is inexpensive, but does not have sufficient heat resistance, has a high elastic modulus, and is easily cracked.

Paste mainly made of resin (hereinafter referred to as “die attach paste”) is widely used because it has sufficient heat resistance, moisture resistance and elastic modulus, and can relieve the stress of expansion and contraction due to thermal history. ing. However, the die attach paste tends to spread out when the viscosity is set in consideration of the coating property, and in the case of a package in which a plurality of dies are mounted on the same package (hereinafter referred to as “multi-chip package”), it is necessary to keep a distance between the dies. Therefore, there is a drawback that it is difficult to cope with high integration of multichip packages.

B-stage conversion has been proposed as a method for solving the drawbacks of such a die attach paste. B-stage is to increase the viscosity or impart thixotropy of the die-attach paste after application by a method such as volatilizing the solvent contained in the die-attach paste or curing only a part of the curing component, or This is a process of preventing the spread of wetness after applying the die attach paste by making the solid solid that can retain its shape.

For example, in Patent Document 1, a connecting material for electronic parts containing a curable compound, a photo radical initiator, and a thermal radical initiator is used, and the connecting material for electronic parts is B-staged and thermally cured by heat compression. Thus, a method for obtaining a connection structure is disclosed. However, in the method disclosed in Patent Document 1, since it is necessary to heat-compress (thermocompression) the connection material for electronic components when obtaining the connection structure, a thermal history is generated in the die due to the thermal load in this heat-compression. As a result, there is a problem that the reliability of the semiconductor package is lowered.

JP 2013-001712 A

The present invention has been made in view of the above-described problems of the prior art, and it is possible to suppress the spread of wetting after coating by making a B stage while maintaining the coating property, and without heating during die bonding. However, it is an object of the present invention to provide a method for manufacturing a semiconductor package that can provide a highly reliable semiconductor package with sufficient adhesion.

As a result of repeated researches to solve the above problems, the present inventors have used a die attach paste for semiconductor containing a photopolymerization initiator, a thermal radical generator, a polyolefin structure-containing resin, and a radical polymerizable compound, and a B stage. By performing die bonding through fabrication, wetting suppression after coating is possible, and sufficient adhesion can be obtained without heating during die bonding, and a highly reliable semiconductor package can be obtained. As a result, the present invention has been completed.

That is, the embodiments of the present invention are as follows [1] to [11].
[1] A semiconductor package manufacturing method including a die bonding step of bonding a die and a support member supporting the die,
In the die bonding step, a die attach paste for semiconductor containing a photopolymerization initiator (1), a thermal radical generator (2), a polyolefin structure-containing resin (3), and a radical polymerizable compound (4) The semiconductor die attach paste is applied to one of the support members, irradiated with light to form a B-stage, and then the die and the support member are placed on the B-stage semiconductor die attach paste. A method of manufacturing a semiconductor package, comprising a step of arranging the other and pressing and joining the die and the support member.

[2] The method for producing a semiconductor package according to [1], wherein the radical polymerizable compound (4) is a (meth) acryloyl group-containing compound.
[3] At least a part of the (meth) acryloyl group-containing compound is a (meth) acryloyl group-containing compound containing both a (meth) acryloyl group and an oxirane ring structure or an oxetane ring structure in the same molecule. The method for producing a semiconductor package according to [2], wherein:

[4] Any one of [1] to [3], wherein the photopolymerization initiator (1) is at least one of an alkylphenone photopolymerization initiator and an acylphosphine oxide photopolymerization initiator. The manufacturing method of the semiconductor package of description.
[5] The photopolymerization initiator (1) according to any one of [1] to [3], wherein the photopolymerization initiator (1) is at least one of an α-aminoalkylphenone photopolymerization initiator and a monoacylphosphine oxide photopolymerization initiator. The manufacturing method of the semiconductor package as described in any one.

[6] The photopolymerization initiator (1) is at least one of a compound represented by the following formula (1) and a compound represented by the following formula (2) [1] to [3] The manufacturing method of the semiconductor package as described in any one of these. However, R ¹ in the following formula (1) is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[7] The method for manufacturing a semiconductor package according to any one of [1] to [6], wherein the thermal radical generator (2) is an organic peroxide.
[8] The method for manufacturing a semiconductor package according to [7], wherein the thermal radical generator (2) is a dialkyl peroxide or a peroxy ester.

[9] The method for producing a semiconductor package according to [7], wherein the thermal radical generator (2) is a compound represented by the following formula (3). However, R ² and R ³ in the following formula (3) are alkylene groups having 1 to 3 carbon atoms.

[10] The production of a semiconductor package according to any one of [7] to [9], wherein the thermal radical generator (2) has a one-minute half-life temperature of 120 ° C. or higher and 200 ° C. or lower. Method.
[11] The irradiation amount of the light in the B-stage is a complex viscosity measured in the condition of a temperature of 25 ° C. and a frequency of 1 Hz of the die-attach paste for semiconductor B-stage is in a range of 100 to 1000 Pa · s. The method of manufacturing a semiconductor package according to any one of [1] to [10], wherein the method is a quantity.

The manufacturing method of the semiconductor package of the present invention can suppress the spread of wetness after coating by making the B stage while maintaining the coating property of the die attach paste for semiconductors, and also provides sufficient adhesion without heating during die bonding. Thus, a highly reliable semiconductor package can be obtained.

Hereinafter, embodiments of the present invention will be described in detail. In the present invention, “(meth) acryloyl group” means an acryloyl group and / or a methacryloyl group.
<Die attach paste for semiconductors>
The die attach paste for semiconductor used in the method for producing a semiconductor package of the present invention comprises a photopolymerization initiator (1), a thermal radical generator (2), a polyolefin structure-containing resin (3), and a radical polymerizable compound (4 )including.

First, the photopolymerization initiator (1) will be described.
The photopolymerization initiator (1) is not particularly limited as long as it is a compound that generates radicals that contribute to the initiation of radical polymerization of the radical polymerizable compound (4) by irradiation with light such as near infrared rays, visible rays, and ultraviolet rays. Absent.
Moreover, a metallocene compound can also be used as a photoinitiator (1). As the metallocene compound, a compound whose central metal is a transition element represented by Fe, Ti, V, Cr, Mn, Co, Ni, Mo, Ru, Rh, Lu, Ta, W, Os, Ir, or the like is used. Examples thereof include bis (η5-2,4-cyclopentadien-1-yl) -bis [2,6-difluoro-3- (pyrrol-1-yl) phenyl] titanium.

More preferable as the photopolymerization initiator (1) used in the present invention are an alkylphenone photopolymerization initiator and an acylphosphine oxide photopolymerization initiator. These photopolymerization initiators are used alone. Alternatively, two or more kinds may be used in appropriate combination. Alkylphenone photopolymerization initiators include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 1,2-hydroxy-2-methyl-1-phenylpropane-1 -One, α-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropanone, 2-hydroxy-2-methyl-1- (4-isopropylphenyl) propanone, 2-hydroxy-2-methyl- 1- (4-dodecylphenyl) propanone, 2-hydroxy-2-methyl-1-[(2-hydroxyethoxy) phenyl] propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1 -Butanone, 2- (dimethylamino) -2- (4-Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, benzoin Benzoin ethers (for example, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin phenyl ether, benzyl dimethyl ketal) and the like.
Examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4,6 -Trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) phenylphosphine oxide, Bis- (2,6-dichlorobenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,6-dichlorobenzoyl) -4-propylphenylphosphine Oxide, bis- (2,6-dichlorobenzoyl) -1-naphthylphosphine oxide, bis- (2,6-dimethoxybenzoyl) phenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4- Trimethylpentylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,5-dimethylphenylphosphine oxide, bis- (2,4,6-trimethylbenzoyl) phenylphosphine oxide, (2,5,6-trimethylbenzoyl) ) -2,4,4-trimethylpentylphosphine oxide and the like.

More preferable examples of the photopolymerization initiator used in the present invention are α-aminoalkylphenone photopolymerization initiators and monoacylphosphine oxide photopolymerization initiators. Examples of the α-aminoalkylphenone photopolymerization initiator include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone and a compound represented by the formula (1). The compound represented by the formula (1) is particularly preferable. However, R ¹ in the following formula (1) is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. These may be used alone or in appropriate combination of two or more.
Examples of the compound represented by the formula (1) include 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone, 2- (dimethylamino) -2-[(4-methyl Phenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2- (dimethylamino) -2-[(4-ethylphenyl) methyl] -1- [4- (4-morpholinyl) ) Phenyl] -1-butanone, 2- (dimethylamino) -2-[(4-n-propynylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone and 2- ( Mention may be made of dimethylamino) -2-[(4-isopropylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone.

Monoacylphosphine oxide photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 2,4, Examples include 6-trimethylbenzoylmethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, and 2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide. Among these monoacylphosphine oxide polymerization initiators, most preferred is 2,4,6-trimethylbenzoyldiphenylphosphine oxide represented by the following formula (2).
And when the storage stability of the die attach paste for semiconductors is taken into consideration, the compound represented by the formula (2) is more preferable than the compound represented by the formula (1).

Examples of commercially available α-aminoalkylphenone photopolymerization initiators include Irgacure 369, Irgacure 379EG (both manufactured by BASF). Moreover, as a commercial item of a monoacylphosphine oxide photopolymerization initiator, DAROCUR TPO (manufactured by BASF), Micure TPO (manufactured by MIWON) and the like can be mentioned.
The amount of the photopolymerization initiator (1) used in the die attach paste for semiconductor is 0.01 to 5 mass with respect to 100 mass parts of the total radical polymerizable compound (4) (for example, (meth) acryloyl group-containing compound). The range of parts is preferable, more preferably 0.05 to 3 parts by mass, and still more preferably 0.1 to 1 part by mass.

If the amount of the photopolymerization initiator (1) used is 0.01 to 5 parts by mass with respect to 100 parts by mass of the total radical polymerizable compound (4) (for example, (meth) acryloyl group-containing compound), Suppression of wetting and spreading due to the B-stage of the die attach paste is easily exhibited, and the B-stage product of the die attach paste for semiconductors does not become too hard, and die bonding can be easily performed by pressure bonding.

Next, the thermal radical generator (2) will be described.
The thermal radical generator (2) is not particularly limited as long as it is a compound that generates a radical that contributes to initiation of radical polymerization of the radical polymerizable compound (4) by heating. Examples of thermal radical generators include azo compounds and organic peroxides, and organic peroxides are preferred as thermal radical generators used in semiconductor die attach pastes.

Examples of the organic peroxide include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, and peroxyester. Among these, those having a one-minute half-life temperature of 120 to 200 ° C. are preferable. More preferred are dialkyl peroxides and peroxyesters having a 1-minute half-life temperature of 120 to 200 ° C., and even more preferred are compounds represented by the general formula (3). However, R ² and R ³ in the following formula (3) are alkylene groups having 1 to 3 carbon atoms.

Examples of commercially available dialkyl peroxides and peroxyesters having a 1-minute half-life temperature of 120 to 200 ° C. include perocta O (manufactured by NOF Corporation), perbutyl O (manufactured by NOF Corporation), and perhexa 25Z (day Oil Mill Co., Ltd.), Park Mill D (manufactured by NOF Corporation), etc.
The amount of the thermal radical generator (2) used in the die attach paste for semiconductor is 0.1 to 10 parts by mass with respect to 100 parts by mass of the total radical polymerizable compound (4) (for example, (meth) acryloyl group-containing compound). The range of parts is preferred, more preferably 0.5 to 6 parts by weight, and still more preferably 1 to 3 parts by weight. If the usage-amount of a thermal radical generating agent (2) is 0.1 mass part or more with respect to 100 mass parts of all radically polymerizable compounds (4), the elasticity modulus of the hardened | cured material of the die attach paste for semiconductors is favorable. It will be something. Moreover, if the usage-amount of a thermal radical generating agent (2) is 10 mass parts or less with respect to 100 mass parts of all radically polymerizable compounds (4), at the time of thermosetting of the die attach paste for semiconductors, or semiconductor package manufacture Outgas is unlikely to occur during the process.

Next, the polyolefin structure-containing resin (3) will be described.
The polyolefin structure-containing resin (3) is not particularly limited as long as it includes a structure obtained by polymerization of unsaturated hydrocarbons. Examples of the unsaturated hydrocarbon include olefins such as α-olefins and diolefins. Examples of the α-olefin include ethylene, propylene, and 1-butene. Examples of the diolefin include butadiene and isoprene. Two or more kinds of copolymers selected from these may be used.
In order to impart adhesiveness and reactivity with other components, particularly reactivity with a ring structure-containing compound containing an oxirane ring structure or oxetane ring structure described later, the polyolefin structure-containing resin (3) is a hydroxyl group, It preferably has a carboxyl group, an acid anhydride group, an epoxy group, an ester structure, and the like. For example, the acid anhydride group can be introduced into the polyolefin structure-containing resin (3) by grafting maleic anhydride, phthalic anhydride, itaconic anhydride, or the like onto the polymer of the olefin.

More preferred examples of the polyolefin structure-containing resin (3) include maleic anhydride-modified polyolefin which is a copolymer of unsaturated hydrocarbon and maleic anhydride. The unsaturated hydrocarbon copolymerized with maleic anhydride is preferably a compound having a conjugated double bond from the viewpoint of stress relaxation of the cured product of the die attach paste for semiconductor, and further prepolymerized with butadiene or isoprene. Or what copolymerized butadiene and isoprene previously is preferable. The maleic anhydride-modified polyolefin preferably has an unsaturated divalent hydrocarbon group. The maleic anhydride-modified polyolefin contains a compound obtained by grafting maleic anhydride onto a polymer obtained by previously polymerizing butadiene or isoprene or a copolymer obtained by copolymerizing butadiene and isoprene in advance.

Examples of commercially available maleic anhydride-modified polyolefin include Diacarna (manufactured by Mitsubishi Chemical Co., Ltd.), M-1000-80 (manufactured by Nippon Petrochemical Co., Ltd.), and Riccon MA (manufactured by CRAYVALLEY).
The number average molecular weight of the polyolefin structure-containing resin (3) is preferably larger than 2000, and more preferably larger than 5000. When the number average molecular weight of the polyolefin structure-containing resin (3) is larger than 2000, the stress relaxation property of the cured product of the die attach paste for semiconductor is improved.

The amount of the polyolefin structure-containing resin (3) used in the die attach paste for semiconductor is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, based on the total cured components. When the amount of the polyolefin structure-containing resin (3) used is 20% by mass or more based on the total amount of the cured components, the stress relaxation property of the cured product of the die attach paste for semiconductor is good. Moreover, if the usage-amount of polyolefin structure containing resin (3) is 80 mass% or less with respect to all the hardening components, the viscosity of the die-attach paste for semiconductors will become favorable, and handling will become easy.

Next, the radical polymerizable compound (4) will be described.
The radically polymerizable compound (4) is not particularly limited as long as it is a compound having radical polymerizability, and examples thereof include a compound having a vinyl group and a compound having a (meth) acryloyl group, and a (meth) acryloyl group. Containing compounds are more preferred. However, the thing which has a (meth) acryloyl group among the silane coupling agents mentioned later is excluded. That is, when the die attach paste for semiconductor contains a silane coupling agent, when the silane coupling agent contains a (meth) acryloyl group, the silane coupling agent having a (meth) acryloyl group is And included in the silane coupling agent and not included in the radical polymerizable compound (4).

Examples of the (meth) acryloyl group-containing compound include polyol poly (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, and (meth) acrylate monomer.
Polyol poly (meth) acrylate is an ester compound of polyol and acrylic acid or methacrylic acid. The polyol selected here is not particularly limited. For example, chain hydrogenated dimer diol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, Neopentyl glycol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 2-ethyl-2-butyl-1, Examples thereof include chain aliphatic polyols such as 3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,10-decanediol, 1,12-dodecanediol, polyolefin polyol, and hydrogenated polyolefin polyol.

The polyol further includes hydrogenated dimer diol having an alicyclic structure, hydrogenated bisphenol A olefin oxide adduct, hydrogenated bisphenol F olefin oxide adduct, hydrogenated biphenol olefin oxide adduct, 1,4-cyclohexanedimethanol. And polyols having an alicyclic structure such as 1,3-cyclohexanedimethanol, tricyclo [5.2.1.02,6] decandimethanol, 2-methylcyclohexane-1,1-dimethanol and the like.

Examples of the polyol further include a polyol having an aromatic ring such as trimer triol, p-xylylene glycol, bisphenol A olefin oxide adduct, bisphenol F olefin oxide adduct, biphenol olefin oxide adduct, and polyethylene. Examples include polyether polyols such as glycol, polypropylene glycol, and polytetramethylene glycol, and polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate, and polycaprolactone.

As the polyol, α, ω-poly (1,6-hexylene carbonate) diol, α, ω-poly (3-methyl-1,5-pentylene carbonate) diol, α, ω-poly [( (Poly) carbonate diols such as 1,6-hexylene: 3-methyl-pentamethylene) carbonate] diol, α, ω-poly [(1,9-nonylene: 2-methyl-1,8-octylene) carbonate] diol Furthermore, polyester polyols having a structural unit derived from a hydrogenated dimer acid and a structural unit derived from a hydrogenated dimer diol can be mentioned. These polyols may be used alone or in combination of two or more.

Also, from the viewpoint of securing the elastic modulus after curing, a polyol having an alicyclic structure, a polyol having an aromatic ring, (poly) carbonate diol, and a polyester polyol are preferred. More preferred is a polyol having an aromatic ring. Examples of commercially available polyol poly (meth) acrylates derived from polyols having an aromatic ring include M-208 (manufactured by Toa Gosei Co., Ltd.), M-211B (manufactured by Toa Gosei Co., Ltd.), FA-321A (Hitachi). Kasei Co., Ltd.), FA-324A (Hitachi Chemical Co., Ltd.), Light acrylate BP-4EAL (Kyoeisha Chemical Co., Ltd.), Light acrylate BP-4PA (Kyoeisha Chemical Co., Ltd.), and the like.

Moreover, epoxy (meth) acrylate is a compound obtained by adding acrylic acid or methacrylic acid to the terminal epoxy group of an epoxy resin. There is no restriction | limiting in particular in the epoxy resin selected in this case. Specifically, for example, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol F type epoxy resin, novolac type epoxy resin, hydrogenated novolac type epoxy resin, glycidyl ester type Examples thereof include an epoxy resin, a biphenyl type epoxy resin, and a hydrogenated biphenyl type epoxy resin. These epoxy (meth) acrylates may be used alone or in appropriate combination of two or more.

Examples of commercially available products of epoxy (meth) acrylate include epoxy ester 3000A (manufactured by Kyoeisha Chemical Co., Ltd.), EBECRYL600 (manufactured by Daicel-Cytec Co., Ltd.), EBECRYL6040 (manufactured by Daicel-Cytech Co., Ltd.) and the like.
Urethane (meth) acrylate is a compound obtained by reacting polyol, polyisocyanate, and hydroxyl group-containing (meth) acrylate, or reacting polyol and isocyanato group-containing (meth) acrylate. There are no particular restrictions on the polyol, polyisocyanate, hydroxyl group-containing (meth) acrylate, and isocyanato group-containing (meth) acrylate selected at this time.

The polyol is the same as the polyol used in the polyol poly (meth) acrylate. Examples of the polyisocyanate include 1,4-cyclohexane diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, , 4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, lysine triisocyanate, lysine diisocyanate, hexamethylene diisocyanate 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexanemethylene diisocyanate, norbornane diisocyanate, etc. And the like. These may be used alone or in appropriate combination of two or more.

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate 2-hydroxy-3- (o-phenylphenoxy) propyl acrylate, 2-hydroxyethyl acrylamide, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl Methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-hydroxy-3- (o-phenylphenoxy) propyl Pill methacrylate, and the like. These may be used alone or in appropriate combination of two or more.

Examples of the isocyanato group-containing (meth) acrylate include 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate. These may be used alone or in appropriate combination of two or more.
Urethane (meth) acrylate is a polyol and a polyisocyanate and a hydroxyl group-containing (meth) acrylate, or a polyol and an isocyanate group in the presence or absence of a known urethanization catalyst such as dibutyltin dilaurate or dioctyltin dilaurate. The synthesis can be performed by reacting the contained (meth) acrylate, but the reaction in the presence of a catalyst is preferable in terms of shortening the reaction time. However, the die attach paste for semiconductor is used as a cured film in the final actual use, but if too much catalyst is used, the physical property value of the cured film may be adversely affected. Therefore, the amount of the catalyst used is 0.001 to 1 part by mass with respect to the total amount of polyol, polyisocyanate, and hydroxyl group-containing (meth) acrylate, or 100 parts by mass of polyol and isocyanato group-containing (meth) acrylate. It is preferable.

The urethanization catalyst catalyzes the hydrolysis reaction of the alkoxysilyl group when the die attach paste for semiconductor contains an alkoxysilyl group. In such a case, it is necessary to consider the balance between the stability over time of the die attach paste for semiconductors and the adhesion to the support member (for example, a lead frame or a substrate), and the amounts used are polyol and polyisocyanate. It is preferably 0.003 to 0.2 parts by mass with respect to 100 parts by mass of the total amount of styrene and hydroxyl group-containing (meth) acrylate, or 100 parts by mass of polyol and isocyanato group-containing (meth) acrylate. More preferably, it is 15 parts by mass. If the amount of the catalyst is 0.001 part by mass or more, the effect of addition of the catalyst is suitably expressed, and if it is 1 part by mass or less, as described above, the final cured product at the time of actual use is used. Good physical properties.

The (meth) acrylate monomer in this specification is a compound obtained by removing the polyol poly (meth) acrylate, the epoxy (meth) acrylate, and the urethane (meth) acrylate from the (meth) acryloyl group-containing compound.
Examples of (meth) acrylate monomers include (meth) acryloyl-containing compounds having a cyclic ether group such as glycidyl acrylate, tetrahydrofurfuryl acrylate, glycidyl methacrylate, and tetrahydrofurfuryl methacrylate, cyclohexyl acrylate, isobornyl acrylate, and dicyclopentenyl. Acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, dicyclopentanyl ethyl acrylate, 4-tert-butylcyclohexyl acrylate, cyclohexyl methacrylate, isobornyl methacrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, Dicyclopentanyl methacrylate, dicyclopentanyl ester Monofunctional (meth) acryloyl group-containing compounds having a cyclic aliphatic group such as methacrylate, 4-tert-butylcyclohexyl methacrylate, lauryl acrylate, isononyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, tert-butyl acrylate, isooctyl Monofunctional (meth) acryloyl group-containing compounds having a chain aliphatic group such as acrylate, isoamyl acrylate, lauryl methacrylate, isononyl methacrylate, 2-ethylhexyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, isooctyl methacrylate, isoamyl methacrylate, Benzyl acrylate, phenoxyethyl acrylate, benzyl methacrylate, phenoxyethyl methacrylate Monofunctional (meth) acryloyl group-containing compounds having an aromatic ring such as acrylate, 2-hydroxy-3-phenoxypropyl methacrylate, polyethylene glycol diacrylate, decanediol diacrylate, nonanediol diacrylate, hexanediol diacrylate, tricyclode Mention may be made of polyfunctional (meth) acryloyl group-containing compounds such as candimethanol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and the like. The monofunctional (meth) acryloyl group-containing compound means a (meth) acryloyl group-containing compound containing one (meth) acryloyl group, and the polyfunctional (meth) acryloyl group-containing compound is a plurality of The (meth) acryloyl group containing compound of (meth) acryloyl group of this is meant.

The amount of the radical polymerizable compound (4) used in the die attach paste for semiconductor is preferably 5 to 80% by mass, more preferably 10 to 60% by mass, and still more preferably based on the total curing component. Is 15 to 50% by mass. If the usage-amount of a radically polymerizable compound (4) is 80 mass% or less with respect to all the hardening components, the adhesiveness to the support member of the hardened | cured material of the die-attach paste for semiconductors will become favorable. Moreover, if the usage-amount of a radically polymerizable compound (4) is 5 mass% or more with respect to all the hardening components, the viscosity of the die-attach paste for semiconductors will become favorable, and handling will become easy.

The “curing component” described in the present specification means a compound that can be polymerized by radical polymerization and / or a ring structure-containing compound and / or an oxirane ring structure or oxetane ring containing an oxirane ring structure or oxetane ring structure described later. It means a compound that can react with the structure, and “total curing component” means the total amount of the curing component. The radical polymerizable compound (4) (for example, a (meth) acryloyl group-containing compound), a ring structure-containing compound containing an oxirane ring structure or an oxetane ring structure, and a maleic anhydride-modified polyolefin are all included in the curing component.

P-styryltrimethoxysilane, p-styryltriethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, 3 in the silane coupling agent described below -No radical polymerization of methacryloyloxypropyltriethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane A silane coupling agent having a saturated group is also included in the curing component.

The (meth) acryloyl group-containing compound used in the present invention includes a (meth) acryloyl group-containing compound (5) containing both a (meth) acryloyl group and an oxirane ring structure or an oxetane ring structure in the same molecule. It is preferable. The (meth) acryloyl group-containing compound (5) containing both the (meth) acryloyl group and the oxirane ring structure or oxetane ring structure in the same molecule is composed of the (meth) acryloyl group and the oxirane ring structure or oxetane ring structure. If it is a compound which contains both in the same molecule, there will be no restriction | limiting in particular.

However, the (meth) acryloyl group-containing compound (5) containing both a (meth) acryloyl group and an oxirane ring structure or an oxetane ring structure in the same molecule is a ring containing an oxirane ring structure or an oxetane ring structure described later. Not included in structure-containing compounds. That is, when the die attach paste for semiconductor contains a (meth) acryloyl group-containing compound (5) containing both a (meth) acryloyl group and an oxirane ring structure or an oxetane ring structure in the same molecule, The (meth) acryloyl group-containing compound (5) containing both an acryloyl group and an oxirane ring structure or an oxetane ring structure in the same molecule shall be included in the (meth) acryloyl group-containing compound, It is not included in a ring structure-containing compound containing an oxetane ring structure.

The (meth) acryloyl group-containing compound (5) containing both the (meth) acryloyl group and the oxirane ring structure or oxetane ring structure in the same molecule is the above-mentioned polyol poly (meth) acrylate, epoxy (meth) acrylate , Urethane (meth) acrylate, and (meth) acrylate monomers containing an oxirane ring structure or an oxetane ring structure.

For example, a polyol poly (meth) acrylate or urethane (meth) acrylate derived from a polyol containing an oxirane ring structure or oxetane ring structure, or an epoxy derived from an epoxy resin containing an oxirane ring structure or oxetane ring structure (meta ) Acrylate and the like. These can be obtained, for example, by making the ratio of the total number of oxirane ring structure or oxetane ring structure contained and the total number of acrylic acid or methacrylic acid to be reacted larger than 1. Examples of (meth) acrylate monomers containing an oxirane ring structure or an oxetane ring structure include glycidyl acrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, and the like.

The amount of the (meth) acryloyl group-containing compound (5) containing both the (meth) acryloyl group and the oxirane ring structure or oxetane ring structure in the same molecule in the semiconductor die attach paste is It is preferable to set it as 10 mass parts or more with respect to 100 mass parts of acryloyl group containing compounds, More preferably, it is 20 mass parts or more, More preferably, it is 30 mass parts or more. The amount of the (meth) acryloyl group-containing compound (5) containing both the (meth) acryloyl group and the oxirane ring structure or oxetane ring structure in the same molecule is 100 parts by mass of the total (meth) acryloyl group-containing compound. On the other hand, if it is 10 parts by mass or more, the elastic modulus of the cured product of the die attach paste for semiconductor will be good.

In the present invention, since the die attach paste for semiconductor preferably contains a ring structure-containing compound containing an oxirane ring structure or an oxetane ring structure, a ring structure-containing compound containing an oxirane ring structure or an oxetane ring structure is added. Sometimes. The ring structure-containing compound containing an oxirane ring structure or oxetane ring structure is not particularly limited as long as it is a compound containing an oxirane ring structure or oxetane ring structure.

Examples of the compound containing an oxirane ring structure or an oxetane ring structure include epichlorohydrin adducts such as alcohols, amines, and carboxylic acids, olefin oxides, cycloadditions of ketones and olefins, oxetane alcohol derivatives, and the like. Examples thereof include epoxy resins used in the above-mentioned epoxy (meth) acrylate, 2-ethylhexyl oxetane, xylylene bisoxetane, and oxetane resins. From the viewpoint of the crosslinking density of the cured product of the die attach paste for semiconductor, the ring structure-containing compound containing an oxirane ring structure or an oxetane ring structure is preferably bifunctional or more, and an epoxy resin is particularly preferable.

The amount of the ring structure-containing compound containing the oxirane ring structure or oxetane ring structure in the die attach paste for semiconductors is derived from the total number of oxirane ring structures or oxetane ring structures and the maleic anhydride-derived maleic anhydride-modified polyolefin described later. The amount is preferably such that the ratio to the total number of carboxylic anhydride structures is 2.8 to 0.4, more preferably 2.0 to 1.2. If the ratio of the total number of oxirane ring structures or oxetane ring structures to the total number of carboxylic anhydride structures derived from maleic anhydride is 2.8 to 0.4, the elastic modulus of the cured product of the die attach paste for semiconductor is good. It will be something.

Moreover, in this invention, since it is preferable that the die-attach paste for semiconductors contains a thermosetting accelerator, a thermosetting accelerator may be added. The thermosetting accelerator is not particularly limited as long as it is a compound that promotes the reaction between the oxirane ring structure or the oxetane ring structure and a compound capable of reacting with them.
Examples of the thermosetting accelerator include alkyl phosphine compounds, imidazole compounds, aliphatic amines, alicyclic amines, cyclic amidines, block compounds such as tetraphenylborate salts, compounds having phenolic hydroxyl groups, polyamides, and carboxylic acids. Anhydride, dicyandiamide, organic acid dihydrazide and the like can be mentioned.

From the viewpoint of balance between curability and storage stability, an imidazole compound, a block compound thereof, and a block compound of cyclic amidine are preferred. Examples of these commercially available products include Curazole 2E4MZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.), Curazole 2PZ-PW (manufactured by Shikoku Kasei Kogyo Co., Ltd.), Curazole 2P4MZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.), Curazole C11Z-CNS (Shikoku Kasei Kogyo Co., Ltd.), U-CAT SA102 (San Apro Co., Ltd.), U-CAT SA506 (San Apro Co., Ltd.), U-CAT 5002 (San Apro Co., Ltd.), and the like.

The amount of the thermosetting accelerator used in the die attach paste for semiconductor is determined based on the ring structure-containing compound containing the oxirane ring structure or oxetane ring structure, and both the (meth) acryloyl group and the oxirane ring structure or oxetane ring structure. The range of 0.5 parts by mass or more and 10 parts by mass or less is preferable with respect to 100 parts by mass of the total of (meth) acryloyl group-containing compound (5) contained in the same molecule, more preferably 1 part by mass or more and 6 parts by mass. Or less.

The use amount of the thermosetting accelerator contains a ring structure-containing compound containing an oxirane ring structure or an oxetane ring structure, and a (meth) acryloyl group and an oxirane ring structure or oxetane ring structure in the same molecule ( If it is 0.5 mass part or more with respect to 100 mass parts of the sum total of (meth) acryloyl group containing compound (5), the elasticity modulus of the hardened | cured material of the die-attach paste for semiconductors will become favorable. In addition, the amount of the thermosetting accelerator used is a ring structure-containing compound containing an oxirane ring structure or an oxetane ring structure, and a (meth) acryloyl group and an oxirane ring structure or oxetane ring structure are contained in the same molecule. If the total amount of the (meth) acryloyl group-containing compound (5) is 10 parts by mass or less, outgas is generated during the thermosetting of the die attach paste for semiconductor or in the semiconductor package manufacturing process. Hateful.

Moreover, in this invention, since it is preferable that the die-attach paste for semiconductors contains a polymerization inhibitor in order to increase storage stability, a polymerization inhibitor may be added. The polymerization inhibitor is not particularly limited. For example, hydroquinone, p-methoxyphenol, p-benzoquinone, naphthoquinone, phenanthraquinone, tolquinone, 2,5-diacetoxy-p-benzoquinone, 2, 5-dicaproxy-p-benzoquinone, 2,5-acyloxy-p-benzoquinone, p-tert-butylcatechol, 2,5-di-tert-butylhydroquinone, p-tert-butylcatechol, mono-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, di-tert-butyl-p-cresol hydroquinone monomethyl ether and phenothiazine are preferably used. These may be used alone or in appropriate combination of two or more.
Usually, this polymerization inhibitor is preferably added in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the total radical polymerizable compound (4).

In the present invention, the die attach paste for a semiconductor can further contain a silane coupling agent for the purpose of imparting adhesion to the support member.
A silane coupling agent is an organosilicon compound having both a functional group reactively bonded to an organic material and a functional group reactively bonded to an inorganic material in the molecule, and its structure is generally represented by the following formula (4). Shown in

Here, Y is a functional group that reacts with an organic material, and representative examples thereof include a vinyl group, an epoxy group, an amino group, a substituted amino group, a (meth) acryloyl group, and a mercapto group. X is a functional group that reacts with the inorganic material and is hydrolyzed by water or moisture to produce silanol, which reacts with the inorganic material. Representative examples of X include an alkoxy group, an acetoxy group, a chloro atom, and the like. R ⁴ is a divalent organic group, and R ⁵ represents an alkyl group. i represents an integer of 1 to 3, and j represents an integer of 0 to 2. However, the sum of i and j is 3.

Among such silane coupling agents, the preferable one is that Y is a radically polymerizable compound (4) (for example, a (meth) acryloyl group-containing compound) and / or a ring structure containing an oxirane ring structure or an oxetane ring structure. Compound and / or a compound having reactivity with maleic anhydride-modified polyolefin, among which p-styryltrimethoxysilane, p-styryltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane , Vinyltris (2-methoxyethoxy) silane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltriethoxysilane, 3-methacryloyloxypro Lutriethoxysilane, 3-acryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-acryloyloxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane 2- (3,4-epoxycyclohexyl) ) Ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N-2 -(Aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyl Liethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxy Silane, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropyltriethoxysilane are preferred.

More preferably, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyl which are easily incorporated into the cured product during the heat curing reaction. Dimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl)- 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- ( 1,3-dimethyl-butylidene) propylamine, N-fur -3- aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyl triethoxysilane are preferred.

In the present invention, the amount of the silane coupling agent relative to the total curing component in the die attach paste for semiconductor is preferably in the range of 0.01% by mass to 8% by mass, and more preferably 0.1% by mass. % Or more and 5% by mass or less. If it is 0.01 mass% or more with respect to all the hardening components in the die-attach paste for semiconductors, the adhesiveness to a supporting member will fully express. Moreover, if it is 8 mass% or less with respect to all the hardening components in the die-attach paste for semiconductors, storage stability will become favorable irrespective of the kind of silane coupling agent to be used.

Moreover, in this invention, since it is preferable that the die-attach paste for semiconductors contains a filler, a filler may be added.
The filler is, for example, a metal filler such as silver powder, gold powder, copper powder, nickel powder, alumina, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, Examples include inorganic fillers such as aluminum oxide, aluminum nitride, crystalline silica, amorphous silica, boron nitride, titania, glass, iron oxide, and ceramics, and organic fillers such as carbon and rubber fillers. There is no restriction in particular. These may be used alone or in appropriate combination of two or more.

These fillers can be used properly according to the purpose. For example, metal fillers are added mainly for the purpose of imparting conductivity to semiconductor die attach pastes, inorganic fillers are added mainly for the purpose of imparting low thermal expansion to semiconductor die attach pastes, and organic fillers are for semiconductors. It is added mainly for the purpose of imparting stress relaxation properties to the die attach paste, and other types of fillers such as thermal conductivity, low hygroscopicity, and insulating properties can be added depending on the purpose.

The filler preferably has an average particle size of 20 μm or less and a maximum particle size of 60 μm or less, more preferably an average particle size of 10 μm or less and a maximum particle size of 30 μm or less. When the average particle size is 20 μm or less and the maximum particle size is 60 μm or less, the storage stability and the coating property of the die attach paste for semiconductor are good.
It is preferable that the compounding quantity of a filler is 5 to 80 mass parts with respect to 100 mass parts of all the hardening components in the die-attach paste for semiconductors. When the blending amount of the filler is 5 parts by mass or more, the elastic modulus of the cured product of the die attach paste for semiconductor is good, and the control of the thermal expansion / contraction rate is easy. On the other hand, when the blending amount of the filler is 80 parts by mass or less, the viscosity of the die attach paste for semiconductor is appropriate.

The die attach paste for semiconductor in the present invention preferably has a viscosity at 25 ° C. of 50000 mPa · s or less. More preferably, the viscosity at 25 ° C. is 25000 mPa · s or less. When the viscosity at 25 ° C. is 50000 mPa · s or less, it becomes easy to apply the die attach paste for a semiconductor with good quantitativeness according to the size of the die.
In the present invention, the shear viscosity of the semiconductor die attach paste was measured using a viscoelasticity measuring device. The typical conditions when performing viscosity measurement using a viscoelasticity measuring device will be described. A sample of a die attach paste for semiconductor was loaded into a viscoelasticity measuring device (manufactured by Anton-Paar, model: MCR301) and sheared using a cone plate spindle of model number CP-25 at a temperature of 25.0 ° C. The shear viscosity is measured at a speed of 10 s- ¹ .

<Semiconductor package manufacturing method>
The semiconductor package manufacturing method of the present invention is generated from a photopolymerization initiator (1) by applying a semiconductor die attach paste to a die or a support member, and then irradiating, for example, ultraviolet rays to an application portion of the semiconductor die attach paste. A part of the curing component such as the radically polymerizable compound (4) is photopolymerized by the radical thus produced, and the die attach paste for semiconductor is made into B stage. After that, for example, die bonding at room temperature such as 25 ° C., and thermosetting of a B-staged semiconductor die attach paste (such as radical polymerizable compound (4) due to radicals generated from thermal radical generator (2)) The remainder of the curing component is thermally polymerized) and further sealed. As a result, a highly reliable semiconductor package with high reliability can be obtained. In addition, you may perform thermosetting and sealing simultaneously.

The coating method of the die attach paste for semiconductor is not particularly limited, and examples thereof include dipping method, brush coating method, spray method, drawing method, stamping method, printing method, jet dispensing method, and ink jet method. The method of irradiating the application part of the semiconductor die attach paste with light such as ultraviolet rays is not particularly limited, but the method of irradiating the application part of the semiconductor die attach paste by holding and operating the flexible light guide tube by hand or machine, And a method of placing a die or a support member coated with a die attach paste for semiconductor on a conveyor and passing through a region irradiated with light such as ultraviolet rays.

The B-stage of the die attach paste for semiconductors is applied so that the complex viscosity at 25 ° C. measured at a frequency of 1 Hz using the vibration mode of the viscoelasticity measuring device is 100 Pa · s to 1000 Pa · s. Is preferred. If the complex viscosity is 100 Pa · s or more and 1000 Pa · s or less, wetting and spreading of the B-stage product of the die attach paste for semiconductors is suppressed in the thermosetting process, and high integration of the semiconductor package is easily achieved. Heating in bonding becomes unnecessary, and it becomes easy to improve reliability without giving an extra heat history to the die.
Specifically, a semiconductor die attach paste is applied to a thickness of 50 μm, irradiated with ultraviolet light having a wavelength of 365 nm to form a B stage, and this B stage semiconductor die attach paste is scraped off with a spatula or the like. The viscoelasticity is measured using the sample as a sample. The viscoelasticity measurement uses a vibration mode of a viscoelasticity measuring device and measures complex viscosity under conditions of a temperature of 25 ° C. and a frequency of 1 Hz. Then, it is preferable to obtain an ultraviolet ray irradiation amount in which the complex viscosity is in the range of 100 to 1000 Pa · s, and to use it as the ultraviolet ray irradiation dose when the semiconductor die attach paste is B-staged.

The B-stage product of the die attach paste for semiconductors is preferably suppressed from spreading during heating so that it does not spread during the thermosetting process. Specifically, a test in which a die attach paste for semiconductor was applied in a circular shape with a thickness of 200 μm and a diameter of 2 mm on a silicon substrate as a support member, and was irradiated with ultraviolet rays at 1000 mJ / cm ² to form a B stage. The piece is put into an oven, heated to 170 ° C. at a heating rate of 4 ° C./min, and cured as it is for 1 hour. Then, the cured die attach paste for semiconductor on the test piece after curing is observed with a microscope to measure the diameter, and the rate of increase in diameter immediately after irradiation with 1000 mJ / cm ^{2 of} ultraviolet rays is calculated. At this time, the increasing rate of the diameter is preferably less than 10%, and more preferably less than 5%.
Furthermore, the amount of ultraviolet irradiation at the time of forming the B stage is such that the rate of change between the diameter of the die attach paste for semiconductor immediately after the ultraviolet irradiation for forming the B stage and the diameter of the cured die attach paste for semiconductor after heat curing is It is preferable that the ultraviolet irradiation amount be less than 10%.

The method of thermosetting after die bonding is performed after the die attach paste for a semiconductor is changed to the B stage is not particularly limited, but a method in which a die and a support member bonded to each other are put into an oven, or a die and a support. For example, a method in which a die-bonded member is placed on a conveyor and passed through a region heated to a predetermined temperature.
A method for evaluating die shear strength when die bonding and thermosetting are performed according to the semiconductor package manufacturing method of the present invention will be described. The die shear strength is evaluated according to standards such as MIL-STD-883G, IEC-60749-22, and EIAJ-ED-4703. As a specific example, using Dage-4000 (shear adhesive strength tester, manufactured by Dage), the side of the bonded die is pushed with a jig with a sensor, and the bond between the die and the support member is broken. Measure the force required. The die shear strength is preferably 58.8 N or more when the square chip of 2 mm square and the support member are joined. If the bonding material or bonding method is 58.8 N or more, the reliability of the semiconductor package is good.

<Semiconductor package>
An aspect of the present invention also includes a semiconductor package manufactured using a semiconductor die attach paste. Semiconductor packages include DO insertion (Pin insertion type) DO package (Diode Outline), TO package (Transistor Outline), DIP (Dual Inline Package), SIP (Single Inline Package), ZIP (Zigzag Inline Package). (Pin Grid Array), surface mount type SOP (Small Outline Package), SOJ (Small Outline J-leaded), CFP (Ceramic Flat Package), SOT (Small Outline Transistor), QFP (Tu, QFP) Plastic Lead d Chip Carrier), BGA (Ball Grid Array), LGA (Land Grid Array), LLCC (Lead Less Chip Carrier), TCP (Tape Carrier Pack), LLP (Leadless Lead Frame) (Chip On Board) and the like.

In the semiconductor package, a semiconductor die attach paste is applied to a die or a support member, and then an application part of the semiconductor die attach paste is irradiated with, for example, ultraviolet rays to form a B stage, and then die bonding and thermosetting are performed, followed by sealing. It can be manufactured by stopping. The semiconductor package manufactured in this way has high reliability.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
Example 1
10.3 g of bisphenol A olefin oxide adduct diacrylate (BP-4EAL, compound name is 2,2′-bis [4- (acryloxypolyethoxy) phenyl] propane manufactured by Kyoeisha Chemical Co., Ltd.), maleic anhydride 41.4 g of modified polybutadiene (Ricon 131 MA17 manufactured by CRAYVALLEY), 6.9 g of glycidyl methacrylate (Blenmer GH manufactured by NOF CORPORATION), 10.3 g of hydrogenated bisphenol A type epoxy resin (YX-8000 manufactured by Mitsubishi Chemical Corporation) , 2,4,6-trimethylbenzoyldiphenylphosphine oxide (BASF DAROCUR TPO) 0.1 g, dicumyl peroxide (NOF Corporation Park Mill D) 0.3 g, diazabicycloundecene-tetraphenyl Borate (U-CAT5002 manufactured by San Apro Co., Ltd.) 0.7 g, spherical silica gel (QS-2 manufactured by Mitsubishi Rayon Co., Ltd.) 29.5 g, 3-glycidoxypropyltrimethoxysilane (KBM-403 manufactured by Shin-Etsu Silicone Co., Ltd.) Was added to and mixed with a rotation / revolution mixer (Shinky Co., Ltd. Awatori Nertaro ARE-310) to obtain a die attach paste.
(Examples 2 to 4, Comparative Examples 1 to 5)
A die attach paste was obtained in the same manner as in Example 1 except that the type and amount of each component were changed as shown in Table 1.

In Table 1, Acryester M is methyl methacrylate manufactured by Mitsubishi Rayon Co., Ltd., SR-349 is ethoxylated bisphenol A diacrylate manufactured by Sartomer, and FA-512M is dicyclopentenyloxyethyl methacrylate manufactured by Hitachi Chemical Co., Ltd. EBECRYL 3702 is an epoxy acrylate manufactured by Daicel-Cytec, CTBN-1300X8 is a carboxy-terminated acrylonitrile butadiene copolymer manufactured by Ube Industries, Ltd., and EXA-4850-150 is an epoxy manufactured by Dainippon Ink & Chemicals, Inc. A resin (epoxy equivalent 450), PB-4700 is an epoxidized polybutadiene manufactured by Daicel Chemical Industries, and UC-203 is a methacryl-modified polyisoprene manufactured by Kuraray Co., Ltd.

Irgacure (registered trademark) 369 is 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 manufactured by BASF, and V-65 is 2,2′- manufactured by Wako Pure Chemical Industries, Ltd. Azobis-2,4-dimethylvaleronitrile, DICY is dicyandiamide, AEROSIL R972 is a hydrophobic silica filler surface-treated with dimethyldichlorosilane manufactured by Nippon Aerosil Co., Ltd., and SFP-20M is Electrochemical Industry Co., Ltd. Spherical silica gel, ASFP-20 is spherical alumina manufactured by Denki Kagaku Kogyo Co., Ltd., and Micropearl AU is gold-plated conductive particles manufactured by Sekisui Chemical Co., Ltd.

<Evaluation of wetting spread suppression>
The suppression of wetting and spreading of the die attach paste was evaluated by the following method.
The die attach paste was applied on a silicon substrate in a circular shape having a thickness of 200 μm and a diameter of 2 mm, and irradiated with 1000 mJ / cm ^{2 of} ultraviolet rays to form a B stage, thereby obtaining a test piece. Thereafter, the test piece was put into an oven, heated to 170 ° C. at a heating rate of 4 ° C./min, and allowed to cure for 1 hour.

The die attach paste on the cured test piece was observed with a microscope, the diameter was measured, the increase rate of the diameter from the time of application was calculated, and the wetting spread suppression was evaluated by the increase rate of the diameter. The results are shown in Table 1. When the increase rate of the diameter was less than 5%, it was evaluated that the wetting and spreading suppression was very good. Further, when the rate of increase in diameter was 5% or more and less than 10%, it was evaluated that the wetting and spreading suppression was good. Further, when the rate of increase in diameter was 10% or more, it was evaluated that the suppression of wetting and spreading was bad, and in Table 1, it was indicated by x.

<Evaluation of die shear strength>
The die shear strength was evaluated by the following method.
A die attach paste was applied in a square shape (thickness of 80 μm) with a side of 2 mm on a square PPF lead frame with a side of 5 mm (three layers plated in the order of Ni, Pd, and Au on a Cu substrate), Ultraviolet rays were irradiated at 1000 mJ / cm ² to make a B stage. Then, using a die bonder MD-P200 (manufactured by Panasonic Corporation), a square silicon chip (thickness 0.7 mm) with a side of 2 mm was placed on the die attach paste under conditions of a temperature of 25 ° C., a load of 10 N, and a time of 1 second. Bonded. Thereafter, it was cured in an oven at 170 ° C. for 1 hour.

The shear strength (N / chip) at 25 ° C. of the product thus obtained was measured using a shear adhesion tester Series 4000 (manufactured by Dage). The results are shown in Table 1. When the measured value of the shear strength was 58.8 N / chip or more, it was evaluated that the die shear strength was good. Moreover, when the measured value of the shear strength was less than 58.8 N / chip, the die shear strength was evaluated to be poor.

<Evaluation of complex viscosity of B-staged product>
The complex viscosity of the B-staged product of the die attach paste was evaluated by the following method. The die attach paste was applied so as to have a thickness of 50 μm, and irradiated with ultraviolet rays under the condition of 1000 mJ / cm ² to form a B stage. The die attach paste made to the B stage was scraped off with a spatula to obtain a sample. The complex viscosity of this sample was measured under the conditions of a temperature of 25 ° C. and a frequency of 1 Hz using the vibration mode of the viscoelasticity measuring device.
When the complex viscosity is in the range of 100 to 1000 Pa · s, it is indicated as “A” in Table 1. In this case, the die attach paste was B-staged well, and both wet spread and die shear strength were good. Further, when the complex viscosity exceeds 1000 Pa · s, it is indicated as “B” in Table 1. In this case, bonding without heating became difficult, and the wet spread of the die attach paste was good, but the die shear strength was inferior. Further, when the complex viscosity is less than 100 Pa · s, it is indicated as “C” in Table 1. In this case, it becomes difficult to suppress wetting and spreading of the die attach paste.

<Evaluation of storage stability>
The storage stability of the die attach paste was evaluated by the following method. The die attach paste was left at a temperature of 25 ° C. for 3 days. Then, the shear viscosity of the die attach paste in the initial stage and after 3 days was measured under the conditions of a temperature of 25 ° C. and a shear rate of 10 s ⁻¹ using the rotation mode of the viscoelasticity measuring apparatus. The viscosity increase rate was calculated from the shear viscosity at the initial stage of standing after 3 days of standing, and the storage stability of the die attach paste was evaluated based on this thickening rate. The results are shown in Table 1.
When the thickening rate was less than 40%, it was evaluated that the storage stability of the die attach paste was very good. Moreover, when the viscosity increase rate was 40% or more and less than 100%, it was evaluated that the storage stability was good. Furthermore, when the viscosity increase rate was 100% or more, it was evaluated that the storage stability of the die attach paste was poor.

From Table 1, Examples 1 to 4, which are die attach pastes containing a photopolymerization initiator, a thermal radical generator, a polyolefin structure-containing resin, and a radical polymerizable compound, have high die shear strength while suppressing wetting and spreading. I understand that. Further, Example 1 using an acylphosphine oxide photopolymerization initiator (DAROCUR TPO) is more storage stable than Examples 2 to 4 using an alkylphenone photopolymerization initiator (Irgacure (registered trademark) 369). Was good.
On the other hand, it can be seen that Comparative Examples 1 and 2, which are die attach pastes that do not contain a thermal radical generator, are inferior in die shear strength because they are not bonded to the support member when die bonded at 25 ° C. Moreover, it turns out that the comparative example 3 which is the die attach paste which does not contain polyolefin structure containing resin also has low die shear strength. That is, the die attach paste containing the photopolymerization initiator, the thermal radical generator, the polyolefin structure-containing resin, and the radical polymerizable compound can suppress the spread of wetting by the B-stage and is higher than the conventional die attach paste. It was found to have die shear strength.

Further, in the die attach paste of Comparative Example 4, tetrahydrophthalic anhydride (B-570H manufactured by DIC Corporation) is used instead of the polyolefin structure-containing resin in such an amount that the acid anhydride structure has the same molar amount. Except for these points, the second embodiment is the same as the first embodiment. Tetrahydrophthalic anhydride has an acid anhydride structure similar to maleic anhydride-modified polybutadiene, which is a polyolefin structure-containing resin of Example 1, but does not contain a polyolefin structure, so that the die shear strength is insufficient.
Further, the die attach paste of Comparative Example 5 is the same as Example 1 except that the polyolefin structure-containing resin is not blended, but since it does not contain the polyolefin structure-containing resin, the die shear strength is insufficient. It was.

According to the method for manufacturing a semiconductor package of the present invention, it is possible to manufacture a highly integrated multi-chip package because the spread of wetting after application can be suppressed by the B-stage while maintaining the applicability of the die attach paste for semiconductor. It is. In addition, since sufficient adhesiveness can be obtained without heating during die bonding, there is no need for thermocompression bonding, and a highly reliable semiconductor package can be manufactured. Therefore, the semiconductor package manufactured by the semiconductor package manufacturing method of the present invention is useful for various devices.

Claims

A method of manufacturing a semiconductor package including a die bonding step of bonding a die and a support member that supports the die,
In the die bonding step, a die attach paste for semiconductor containing a photopolymerization initiator (1), a thermal radical generator (2), a polyolefin structure-containing resin (3), and a radical polymerizable compound (4) The semiconductor die attach paste is applied to one of the support members, irradiated with light to form a B-stage, and then the die and the support member are placed on the B-stage semiconductor die attach paste. A method of manufacturing a semiconductor package, comprising a step of arranging the other and pressing and joining the die and the support member.
The method for producing a semiconductor package according to claim 1, wherein the radical polymerizable compound (4) is a (meth) acryloyl group-containing compound.
At least a part of the (meth) acryloyl group-containing compound is a (meth) acryloyl group-containing compound containing both a (meth) acryloyl group and an oxirane ring structure or an oxetane ring structure in the same molecule. A method of manufacturing a semiconductor package according to claim 2.
4. The semiconductor package according to claim 1, wherein the photopolymerization initiator (1) is at least one of an alkylphenone photopolymerization initiator and an acylphosphine oxide photopolymerization initiator. Manufacturing method.
4. The photopolymerization initiator (1) according to any one of claims 1 to 3, wherein the photopolymerization initiator (1) is at least one of an α-aminoalkylphenone photopolymerization initiator and a monoacylphosphine oxide photopolymerization initiator. The manufacturing method of the semiconductor package of description.
The photopolymerization initiator (1) is at least one of a compound represented by the following formula (1) and a compound represented by the following formula (2). The manufacturing method of the semiconductor package of description. However, R 1 in the following formula (1) is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
The method for manufacturing a semiconductor package according to any one of claims 1 to 6, wherein the thermal radical generator (2) is an organic peroxide.
The method for manufacturing a semiconductor package according to claim 7, wherein the thermal radical generator (2) is a dialkyl peroxide or a peroxy ester.
The method of manufacturing a semiconductor package according to claim 7, wherein the thermal radical generator (2) is a compound represented by the following formula (3). However, R 2 and R 3 in the following formula (3) are alkylene groups having 1 to 3 carbon atoms.
10. The method of manufacturing a semiconductor package according to claim 7, wherein the one-minute half-life temperature of the thermal radical generator (2) is 120 ° C. or higher and 200 ° C. or lower.
The irradiation amount of the light in the B-stage is such that the complex viscosity measured under the conditions of a temperature of 25 ° C. and a frequency of 1 Hz of the B-staged die attach paste for semiconductor is in the range of 100 to 1000 Pa · s. The method of manufacturing a semiconductor package according to any one of claims 1 to 10, wherein: