JP2019011409A - Underfill material, semiconductor package and method for producing semiconductor package - Google Patents

Abstract

To provide an underfill material that can suppress an increased thermal expansion coefficient of a cured product and reduce the viscosity during its filling, and a semiconductor package obtained by using the same and a method for producing the same.SOLUTION: An underfill material contains epoxy resin, a curing agent, and a filler, the epoxy resin having an epoxy compound represented by general formula (1). In general formula (1), R is a C1-5 hydrocarbon group; n is the number of R's to represent an integer of 0-5.SELECTED DRAWING: None

Description

  The present invention relates to an underfill material, a semiconductor package, and a method for manufacturing a semiconductor package.

In semiconductor device mounting technology, a liquid underfill material called an underfill material is widely used to fill a gap between a substrate and a semiconductor chip.
For example, Patent Document 1 describes a liquid sealing material that achieves good injectability and suppression of fillet cracks after sealing by blending a specific amount of an aminophenol epoxy resin with a bisphenol-type epoxy resin.

International Publication No. 2016/093148

The underfill material generally contains a filler, but when the amount of the filler is increased, the viscosity of the underfill material increases and the pouring property tends to decrease. Therefore, attempts have been made to lower the viscosity by blending an epoxy resin called a reactive diluent. However, when the amount of the reactive diluent is increased, the thermal expansion coefficient of the cured product of the underfill material tends to increase. If the thermal expansion coefficient of the cured product of the underfill material is high, the difference from the thermal expansion coefficient of the semiconductor chip becomes large, and this causes defects in reliability tests such as reflow resistance and temperature cycle resistance. Or the amount of warpage of the semiconductor device tends to increase.
Therefore, it is desired to design an underfill material that can achieve a reduction in viscosity at the time of filling while suppressing an increase in the thermal expansion coefficient of the cured product.
In view of the above circumstances, an object of the present invention is to provide an underfill material capable of achieving both suppression of increase in the thermal expansion coefficient of a cured product and reduction in viscosity at the time of filling, a semiconductor package obtained using the underfill material, and a method for manufacturing the same. And

<1> An underfill material containing an epoxy resin, a curing agent, and a filler, wherein the epoxy resin contains an epoxy compound represented by the following general formula (1).

[In General formula (1), R represents a C1-C5 hydrocarbon group. n represents the number of R and is an integer of 0-5. ]

<2> The underfill material according to <1>, wherein the content of the filler is 60% by mass or more of the entire underfill material.

<3> The underfill material according to <1> or <2>, wherein the epoxy compound represented by the general formula (1) includes an epoxy resin in which R is a methyl group and n is 1.

<4> The content of the epoxy compound represented by the general formula (1) is 1% by mass to 30% by mass of the entire underfill material, according to any one of <1> to <3>. Underfill material.

<5> Any one of <1> to <4>, wherein the epoxy resin includes at least one selected from the group consisting of a bisphenol-based epoxy resin, a naphthalene-based epoxy resin, and a tri- or higher functional glycidylamine-based epoxy resin. The underfill material according to the item.

<6> The underfill material according to any one of <1> to <5>, wherein the curing agent is an amine curing agent.

<7> a support, a semiconductor element disposed on the support, and a cured product of the underfill material according to any one of <1> to <6> sealing the semiconductor element; A semiconductor package comprising:

<8> A step of filling a gap between the support and the semiconductor element disposed on the support with the underfill material according to any one of <1> to <6>, and the underfill And a step of curing the material.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition for sealing which can make compatible suppression of the raise of the thermal expansion coefficient of hardened | cured material and the viscosity reduction at the time of filling, a semiconductor package obtained using this, and its manufacturing method are provided.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and ranges thereof, and the present invention is not limited thereto.

In the present disclosure, the term “process” includes a process that is independent of other processes and includes the process if the purpose of the process is achieved even if it cannot be clearly distinguished from the other processes. .
In the present disclosure, the numerical ranges indicated using “to” include numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the numerical ranges described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical description. . Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.
In the present disclosure, each component may contain a plurality of corresponding substances. When multiple types of substances corresponding to each component are present in the composition, the content or content of each component is the total content or content of the multiple types of substances present in the composition unless otherwise specified. Means quantity.
In the present disclosure, a plurality of particles corresponding to each component may be included. When a plurality of particles corresponding to each component are present in the composition, the particle diameter of each component means a value for a mixture of the plurality of particles present in the composition unless otherwise specified.

<Underfill material>
The underfill material of the present embodiment includes an epoxy resin, a curing agent, and a filler, and the epoxy resin includes an epoxy compound represented by the following general formula (1) (hereinafter also referred to as a specific epoxy resin). .

  In the general formula (1), R represents a hydrocarbon group having 1 to 5 carbon atoms. n represents the number of R and is an integer of 0-5.

As a result of the study by the present inventors, it has been found that the underfill material containing the specific epoxy resin can achieve both the suppression of the increase in the thermal expansion coefficient of the cured product and the reduction of the viscosity at the time of filling. Although the reason is not clear, in addition to having the property as a reactive diluent that the specific epoxy resin compounded in the epoxy resin reduces the viscosity of the underfill material, the epoxy used as another reactive diluent This is presumably because the coefficient of thermal expansion of the cured product is less likely to increase as compared with the case where a resin is blended.
An underfill material containing a specific epoxy resin can achieve both suppression of increase in the coefficient of thermal expansion of the cured product and reduction in viscosity at the time of filling. For example, it is possible to increase the amount of filler while suppressing increase in viscosity. .

  The underfill material preferably has a sufficiently low viscosity when filling the gap between the substrate and the semiconductor chip. Specifically, the viscosity at 110 ° C. is preferably 1.0 Pa · s or less, more preferably 0.75 Pa · s or less, and further preferably 0.50 Pa · s or less. In the present disclosure, the viscosity of the underfill material at 110 ° C. is measured with a rheometer (for example, “AR2000” manufactured by TA Instruments Japan Co., Ltd.) on a parallel plate of 40 mm and a shear rate of 32.5. It is a value measured under the condition of / sec.

[Epoxy resin]
An epoxy resin will not be restrict | limited especially if the specific epoxy resin represented by General formula (1) is included. A specific epoxy resin may be used individually by 1 type, or may use 2 or more types together.

  In the general formula (1), examples of the hydrocarbon group having 1 to 5 carbon atoms represented by R include an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 1 to 5 carbon atoms. An alkyl group is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group is more preferable.

  In the general formula (1), n is preferably an integer of 0 to 3, more preferably 0 or 1, and further preferably 1.

  In general formula (1), when n is 1 or more, it is preferable that any one or more of R is in the ortho position with respect to the diglycidylamino group.

  Specific examples of the specific epoxy resin include a compound in which n is 0 (N, N- (diglycidyl) -aniline), R is a methyl group in the ortho position with respect to the diglycidylamino group, and n is 1. A compound (N, N- (diglycidyl) -o-toluidine) and the like. These are also available as commercial products. As a commercial item of N, N- (diglycidyl) -aniline, for example, trade name “GAN” of Nippon Kayaku Co., Ltd. can be mentioned, and as a commercial item of N, N- (diglycidyl) -o-toluidine, for example, , Trade name “ADEKA RESIN EP-3980S” of ADEKA Corporation and trade name “GOT” of Nippon Kayaku Co., Ltd.

  From the viewpoint of achieving both suppression of increase in the thermal expansion coefficient of the cured product and reduction in viscosity at the time of filling, the content of the specific epoxy resin is preferably 1% by mass to 50% by mass of the entire epoxy resin, and 5% by mass. More preferably, it is -30 mass%.

  When the epoxy resin includes an epoxy resin other than the specific epoxy resin, the epoxy resin other than the specific epoxy resin is not particularly limited. For example, bisphenol type epoxy resin, naphthalene type epoxy resin, glycidylamine type epoxy resin, hydrogenated bisphenol type epoxy resin, alicyclic epoxy resin, alcohol ether type epoxy resin, cyclic aliphatic type epoxy resin, fluorene type epoxy resin, and A siloxane type epoxy resin is mentioned. Epoxy resins other than the specific epoxy resin may be used alone or in combination of two or more.

  Among the above-mentioned epoxy resins, it preferably contains at least one selected from the group consisting of bisphenol-type epoxy resins, naphthalene-type epoxy resins and tri- or more functional glycidylamine-type epoxy resins, bisphenol-type epoxy resins, naphthalene-type epoxy resins and It is more preferable that each glycidylamine type epoxy resin having three or more functions is included.

  The type of the bisphenol type epoxy resin is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol AD type epoxy resin. In order to be used as an underfill material, the bisphenol type epoxy resin is preferably liquid at room temperature (25 ° C.), and more preferably bisphenol F type epoxy resin that is liquid at room temperature (25 ° C.). The bisphenol-type epoxy resin that is liquid at room temperature (25 ° C.) is also available as a commercial product. As a commercial item of the liquid bisphenol F-type epoxy resin at room temperature (25 ° C.), for example, “Epototo YDF-8170C” trade name of Nippon Steel & Sumikin Chemical Co., Ltd. may be mentioned.

  The ratio of the bisphenol-type epoxy resin to the entire epoxy resin is not particularly limited, and can be selected according to the desired characteristics of the underfill material. For example, it can select from the range of 20 mass%-90 mass%.

  The kind of naphthalene type epoxy resin is not particularly limited. The naphthalene type epoxy resin used for the underfill material is preferably liquid at normal temperature (25 ° C.). Examples of the naphthalene type epoxy resin that is liquid at normal temperature (25 ° C.) include 1,6-bis (glycidyloxy) naphthalene. 1,6-bis (glycidyloxy) naphthalene is also available as a commercial product. As a commercial item, the brand name "Epiclon HP-4032D" of DIC Corporation is mentioned, for example.

  When the underfill material contains a naphthalene type epoxy resin epoxy resin as an epoxy resin, the ratio is not particularly limited. For example, the proportion of the entire epoxy resin is preferably 10% by mass or more from the viewpoint of suppressing the increase in the coefficient of thermal expansion, and is preferably 50% by mass or less from the viewpoint of the balance of properties as the underfill material. .

  The kind of tri- or more functional glycidylamine type epoxy resin is not particularly limited. The trifunctional or higher functional glycidylamine type epoxy resin used as the underfill material is preferably liquid at room temperature (25 ° C.).

  Triglycidyl-p-aminophenol is mentioned as a tri- or higher functional glycidylamine type epoxy resin that is liquid at normal temperature (25 ° C.). Triglycidyl-p-aminophenol is also available as a commercial product. As a commercial item, the brand name "jER-630" and "jER-630LSD" of Mitsubishi Chemical Corporation, and the brand name "EP-3950S" of ADEKA Corporation are mentioned, for example.

  When the underfill material contains a tri- or higher functional glycidylamine type epoxy resin as an epoxy resin, the ratio is not particularly limited. For example, the proportion of the entire epoxy resin is preferably 10% by mass or more from the viewpoint of improving heat resistance, and is preferably 50% by mass or less from the viewpoint of balance of characteristics as the underfill material.

[Curing agent]
The kind in particular of hardening | curing agent is not restrict | limited, It can select according to the desired characteristic etc. of an underfill material. Examples thereof include amine curing agents, phenol curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents. A hardening | curing agent may be used individually by 1 type, or may be used in combination of 2 or more type.

  The curing agent used for the underfill material is preferably liquid at room temperature (25 ° C.), and is preferably an amine curing agent from the viewpoint of adhesion to the adherend. Examples of amine curing agents include aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4′-diamino-dicyclohexylmethane, diethyltoluenediamine, 3, Aromatic amine compounds such as 3′-diethyl-4,4′-diaminodiphenylmethane and 2-methylaniline, imidazole compounds such as imidazole, 2-methylimidazole, 2-ethylimidazole and 2-isopropylimidazole, imidazoline and 2-methyl Examples include imidazoline compounds such as imidazoline and 2-ethylimidazoline. Of these, aromatic amine compounds are preferred.

  The ratio of the epoxy resin to the curing agent is the ratio of the number of functional groups of the curing agent (active hydrogen in the case of an amine curing agent) to the number of epoxy groups in the epoxy resin (in terms of reducing the amount of unreacted components) The number of functional groups of the curing agent / the number of epoxy groups of the epoxy resin) is preferably set to be in the range of 0.5 to 2.0, and is set to be in the range of 0.6 to 1.3. More preferably. From the viewpoints of moldability and reflow resistance, it is more preferable to set it within the range of 0.8 to 1.2.

[filler]
The kind of filler is not particularly limited. Specifically, silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc And inorganic materials such as clay and mica. You may use the filler which has a flame-retardant effect. Examples of the filler having a flame retardant effect include aluminum hydroxide, magnesium hydroxide, composite metal hydroxide such as composite hydroxide of magnesium and zinc, zinc borate and the like.

  Among the fillers, silica is preferable from the viewpoint of reducing the coefficient of thermal expansion, and alumina is preferable from the viewpoint of improving thermal conductivity. A filler may be used individually by 1 type, or may be used in combination of 2 or more type.

  The content rate of the filler contained in the underfill material is not particularly limited. From the viewpoint of reducing the coefficient of thermal expansion after curing, the higher the filler content, the better. For example, it is preferably 60% by mass or more, and more preferably 64% by mass or more of the entire underfill material. On the other hand, from the viewpoint of suppressing the increase in viscosity, the smaller the filler content, the better. For example, it is preferable that it is 90 mass% or less of the whole underfill material.

  When the filler is particulate, the average particle size is not particularly limited. For example, the volume average particle diameter is preferably 0.05 μm to 20 μm, and more preferably 0.1 μm to 15 μm. There exists a tendency for the raise of the viscosity of an underfill material to be suppressed more as a volume average particle diameter is 0.05 micrometer or more. When the volume average particle size is 20 μm or less, the filling property into a narrow gap tends to be further improved. The volume average particle diameter of the filler can be measured as the particle diameter (D50) when the cumulative volume from the small diameter side is 50% in the volume-based particle size distribution obtained by the laser scattering diffraction particle size distribution analyzer. it can.

[Various additives]
The underfill material may contain various additives such as a curing accelerator, a stress relaxation agent, a coupling agent, and a colorant in addition to the above-described components. The underfill material may contain various additives well known in the art as necessary, in addition to the additives exemplified below.

(Curing accelerator)
The underfill material may include a curing accelerator. The type of curing accelerator is not particularly limited, and can be selected according to the types of epoxy resin and curing agent, desired characteristics of the underfill material, and the like.

  When the underfill material contains a curing accelerator, the amount is preferably 0.1 parts by mass to 30 parts by mass with respect to 100 parts by mass of the curable resin component (total of epoxy resin and curing agent). It is more preferable that it is 15-15 mass parts.

(Stress relaxation agent)
The underfill material may include a stress relaxation agent. Examples of the stress relaxation agent include particles of thermoplastic elastomer, NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, silicone rubber, and the like. A stress relaxation material agent may be used individually by 1 type, or may be used in combination of 2 or more type.

  When the underfill material includes a stress relaxation agent, the amount is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the curable resin component (total of epoxy resin and curing agent), and 1 mass. It is more preferable that it is 15-15 mass parts.

(Coupling agent)
The underfill material may include a coupling agent. Examples of the coupling agent include silane compounds such as epoxy silane, phenyl silane, mercapto silane, amino silane, phenyl amino silane, alkyl silane, ureido silane, and vinyl silane, titanium compounds, aluminum chelate compounds, and aluminum / zirconium compounds. Of these, silane compounds (silane coupling agents) are preferred. A coupling agent may be used individually by 1 type, or may be used in combination of 2 or more type.

  When the underfill material includes a coupling agent, the amount of the coupling agent is preferably 0.05 parts by mass to 5 parts by mass with respect to 100 parts by mass of the filler, and 0.1 parts by mass to 2.5 parts by mass. More preferably, it is part by mass.

(Coloring agent)
The underfill material may include a colorant. Examples of the colorant include carbon black, organic dyes, organic pigments, titanium oxide, red lead, bengara and the like. A coloring agent may be used individually by 1 type, or may be used in combination of 2 or more type.

  When the underfill material contains a colorant, the amount is preferably 0.01 parts by mass to 10 parts by mass with respect to 100 parts by mass of the curable resin component (total of epoxy resin and curing agent). More preferably, it is 5 parts by mass.

(Use of underfill material)
The underfill material can be used for various mounting techniques. In particular, it can be suitably used as an underfill material used in flip chip mounting technology. For example, it can be suitably used for a purpose of filling a gap between a semiconductor element bonded by a bump or the like and a support.

  The types of the semiconductor element and the support are not particularly limited, and can be selected from those generally used in the field of semiconductor packages. The method for filling the gap between the semiconductor element and the support using the underfill material is not particularly limited. For example, it can be performed by a known method using a dispenser or the like.

<Semiconductor package>
The semiconductor package of the present embodiment includes a support, a semiconductor element disposed on the support, and a cured product of the above-described underfill material that seals the semiconductor element.

  In the semiconductor package, the types of the semiconductor element and the support are not particularly limited, and can be selected from those generally used in the field of semiconductor packages. Since the thermal expansion coefficient of the cured product of the underfill material is reduced in the semiconductor package, for example, when a stress is generated between the cured product of the underfill material and the semiconductor element, the semiconductor package has an excellent effect of suppressing this. Yes.

<Semiconductor package manufacturing method>
The method of manufacturing a semiconductor package according to the present embodiment includes a step of filling a gap between a support and a semiconductor element disposed on the support with the above-described underfill material, and a step of curing the underfill material. And having.

  In the above method, the types of the semiconductor element and the support are not particularly limited, and can be selected from those generally used in the field of semiconductor packages. The method for filling the gap between the semiconductor element and the support using the underfill material and the method for curing the underfill material after filling are not particularly limited, and can be performed by a known method.

  Hereinafter, the underfill material of the present disclosure will be specifically described with reference to examples, but the scope of the present disclosure is not limited to these examples.

(Preparation of underfill material)
The components shown in Table 1 were mixed in the amounts (parts by mass) shown in Table 1 to prepare an underfill material. Details of each component are as follows. The blending ratio of the epoxy resin and the curing agent was set so that the number of epoxy groups of the epoxy resin and the number of active hydrogens of the curing agent were equal.

Epoxy resin 1 ... Liquid bisphenol F type epoxy resin, epoxy equivalent: 160 g / eq, trade name "Epototo YDF-8170C", Nippon Steel & Sumikin Chemical Co., Ltd. Epoxy resin 2 ... Triglycidyl-p-aminophenol, epoxy equivalent: 95 g / eq , Trade name "jER 630", Mitsubishi Chemical Corporation Epoxy resin 3 ... 1,6-bis (glycidyloxy) naphthalene, epoxy equivalent: 143 g / eq, trade name "Epicron HP-4023D", DIC Corporation

Epoxy resin 4 ... N, N- (diglycidyl) -o-toluidine, epoxy equivalent: 115 g / eq, trade name “ADEKA RESIN EP-3980S”, ADEKA Corporation
Epoxy resin 5 ... 1,4-butanediol diglycidyl ether, epoxy equivalent: 102 g / eq, trade name "SR-14BJ", Sakamoto Yakuhin Co., Ltd. Epoxy resin 6 ... trimethylolpropane triglycidyl ether, epoxy equivalent: 120, Product name “Epototo ZX-1542”, Nippon Steel & Sumikin Chemical Co., Ltd.

Curing agent 1 ... diethyltoluenediamine, trade name “jER Cure W”, active hydrogen equivalent: 45 g / eq, Mitsubishi Chemical Corporation Curing agent 2 ... 3,3′-diethyl-4,4′-diaminodiphenylmethane, trade name “ Kayahard AA ", active hydrogen equivalent: 63 g / eq, Nippon Kayaku Co., Ltd.

Filler: spherical silica having a volume average particle size of 0.5 μm, trade name “SE2200”, Admatex Co., Ltd. coupling agent… 3-glycidoxypropyltrimethoxysilane, trade name “Syra Ace S510”, JNC Corporation Coloring Agent: carbon black, trade name "MA-100", Mitsubishi Chemical Corporation

(Measurement of viscosity at 110 ° C.)
Using a rheometer (“AR2000” manufactured by TA Instruments Japan Co., Ltd.) as the underfill material, a value measured on a 40 mm parallel plate under a shear rate of 32.5 / sec was 110. It was set as the viscosity in ° C.

(Measurement of thermal expansion coefficient)
The cured product obtained by heat-molding the underfill material into a cylindrical shape having a diameter of 8 mm and a length of 20 mm at 150 ° C. for 2 hours was heated using TMA (thermomechanical analysis, TA4000SA manufactured by TA Instruments). Measurement was performed at a rate of 3 ° C./min and a measurement temperature range of 0 to 250 ° C., and a linear gradient of 0 ° C. to 30 ° C. was defined as a linear expansion coefficient.

As shown in Table 1, the underfill material blended with the specific epoxy resin has the same filler content as the underfill material blended with no specific epoxy resin (Examples 1 and 2 and Comparative Example 1). Examples 3 to 5 and Comparative Example 6, Examples 6 to 8 and Comparative Examples 7 and 8) had low viscosity values at 110 ° C. Moreover, the underfill material which mix | blended specific epoxy resin has the same content rate of a filler, and compared with the underfill material which mix | blended the epoxy resin generally used as a reactive diluent (Example 1 and 2 and Comparative Example 2). 5) The value of the coefficient of thermal expansion of the cured product was small.
As mentioned above, it turned out that the viscosity at the time of filling can be reduced by mix | blending specific epoxy resin as an epoxy resin, suppressing the raise of the thermal expansion coefficient of the hardened | cured material of an underfill material.

Claims (8)

An underfill material comprising an epoxy resin, a curing agent, and a filler, wherein the epoxy resin contains an epoxy compound represented by the following general formula (1).

[In General formula (1), R represents a C1-C5 hydrocarbon group. n represents the number of R and is an integer of 0-5. ]   The underfill material according to claim 1, wherein a content of the filler is 60% by mass or more of the entire underfill material.   The underfill material according to claim 1 or 2, wherein the epoxy compound represented by the general formula (1) includes an epoxy resin in which R is a methyl group and n is 1.   The content rate of the epoxy compound represented by the said General formula (1) is 1 mass%-30 mass% of the whole said underfill material, The underfill material of any one of Claims 1-3. .   The said epoxy resin contains at least 1 sort (s) selected from the group which consists of a bisphenol type | system | group epoxy resin, a naphthalene type | system | group epoxy resin, and a trifunctional or more than trifunctional glycidyl amine type | system | group epoxy resin, The any one of Claims 1-4. Underfill material.   The underfill material according to claim 1, wherein the curing agent is an amine curing agent.   The support body, the semiconductor element arrange | positioned on the said support body, and the hardened | cured material of the underfill material of any one of Claims 1-6 which has sealed the said semiconductor element. Semiconductor package.   The process of filling the space | gap between a support body and the semiconductor element arrange | positioned on the said support body with the underfill material of any one of Claims 1-6, and hardening the said underfill material. A method of manufacturing a semiconductor package.