JP2010229257A - Epoxy resin composition and semiconductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition excellent in adhesiveness to members constituting a semiconductor and excellent in both curability and storage stability, and to provide a semiconductor fabricated by sealing a semiconductor device with the same. <P>SOLUTION: An epoxy resin composition including an epoxy resin, a curing agent, and a curing promoter is liquid at ambient temperature, wherein the curing agent includes a mercaptocarboxylate ester compound containing three SH groups per molecule and a tetrahydrophthalic anhydride compound containing three hydrocarbon groups per molecule, and the content of the mercaptocarboxylate ester is 5-50 mass% based on the total amount of the curing agent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition and a semiconductor device formed by sealing and molding a semiconductor element with the epoxy resin composition.

  A semiconductor device is obtained by sealing a semiconductor element such as a silicon chip or a member such as a substrate with a sealing material to form a semiconductor package. And as a sealing material used when sealing the said member, in order to improve the reliability of the semiconductor device obtained, it is desired that the adhesiveness with respect to the members which comprise semiconductor devices, such as a semiconductor element, is high. Yes. As such a highly adhesive sealing material, for example, an epoxy resin composition that is liquid at room temperature is known. Since the epoxy resin composition that is liquid at room temperature does not need to be molded using a mold at the time of sealing, it is not necessary to contain a release agent. Therefore, an epoxy resin composition that is liquid at room temperature is generally a member that constitutes a semiconductor device such as a semiconductor element from a sealing material containing a release agent, which is used in a sealing method using a mold. It is known that the adhesiveness with respect to becomes high.

  On the other hand, in the process of sealing with a sealing material, in order to improve the production efficiency of a semiconductor device, shortening of the hardening time of the epoxy resin composition used as a sealing material is desired. Moreover, it is preferable that heat is not applied as much as possible to a member constituting a semiconductor such as a semiconductor element, and a sealing material that can be cured even at a relatively low temperature is demanded. For this reason, it has been attempted to increase the curability of the epoxy resin composition by examining the curing agent contained in the epoxy resin composition which is a sealing material.

As a hardening | curing agent contained in an epoxy resin composition, the hardening | curing agent described in the following patent document 1, etc. are mentioned, for example. In the following Patent Document 1, as an curing agent contained in an epoxy resin composition containing an oxazolidone ring and an epoxy resin composition containing a heat stabilizer, amine-based, acid anhydride-based, phenol-based, mercaptan-based, imidazole-based And BF ₃ based curing agents are described.

JP-A-8-127635

  As the curing agent in the epoxy resin composition that is a sealing material, for example, by examining the curing agent from among various curing agents as described in Patent Document 1, the curability of the epoxy resin composition can be increased. Even if it is increased, there are cases where the storage stability at room temperature deteriorates and the pot life after opening, that is, the so-called pot life is shortened. Further, in some cases, the epoxy resin composition may change over time even during sealing before opening. Such an epoxy resin composition that has changed over time may have decreased fluidity and the like, and may have poor filling. That is, it was difficult to obtain a liquid epoxy resin composition excellent in both curability and storage stability.

  The present invention has been made in view of such circumstances, and is to provide an epoxy resin composition having excellent adhesion to members constituting a semiconductor device, and further excellent in both curability and storage stability. Objective. Another object of the present invention is to provide a semiconductor device formed by sealing and molding a semiconductor element with the epoxy resin composition.

  The epoxy resin composition of the present invention is an epoxy resin composition that is liquid at room temperature containing an epoxy resin, a curing agent, and a curing accelerator, and the curing agent has three SH groups in one molecule. Including a carboxylic acid ester compound and a tetrahydrophthalic anhydride compound having three hydrocarbon groups in one molecule, wherein the content of the mercaptocarboxylic acid ester compound is 5 to 50% by mass relative to the total amount of the curing agent. It is characterized by being.

  According to such a configuration, an epoxy resin composition having excellent adhesion to members constituting the semiconductor device and further excellent in both curability and storage stability can be obtained.

  This is because, first, the mercaptocarboxylic acid ester compound increases the curability without impairing the high adhesion of the epoxy resin composition that is liquid at room temperature to the members constituting the semiconductor device, and in particular, the curability at low temperatures. It is thought that it can raise. The tetrahydrophthalic anhydride compound can reduce impure ions in the epoxy resin composition as compared with other curing agents, and the reduction of the impure ions can improve the moisture resistance of the epoxy resin composition. It is considered possible. Therefore, it is considered that by improving the moisture resistance, moisture absorption from the interface with the member constituting the semiconductor device can be suppressed, and the adhesion to the member constituting the semiconductor device can be further increased. Furthermore, when the tetrahydrophthalic anhydride compound is used in combination with the mercaptocarboxylic acid ester compound, the curability of the epoxy resin composition can be adjusted, and the storage stability is maintained while suitably maintaining the curability of the epoxy resin composition. It is thought that it can raise. From the above, as the curing agent, the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound are used in combination, and by specifying the content of the mercaptocarboxylic acid ester compound in the curing agent, it is liquid at room temperature. It is thought that it is possible to achieve both curability and storage stability without impairing the high adhesion of the epoxy resin composition to the members constituting the semiconductor device.

  Moreover, it is preferable that the said mercaptocarboxylic acid ester compound is a compound represented by following formula (1).

  According to such a configuration, a liquid epoxy resin composition having excellent adhesion to members constituting the semiconductor device can be obtained which is excellent in curability and storage stability.

  Moreover, it is preferable that the said tetrahydrophthalic anhydride compound is a compound represented by following formula (2).

  According to such a configuration, a liquid epoxy resin composition having excellent adhesion to members constituting the semiconductor device can be obtained which is excellent in curability and storage stability.

  The semiconductor device of the present invention is obtained by sealing and molding a semiconductor element with the epoxy resin composition.

  According to such a configuration, the semiconductor element is encapsulated by using an epoxy resin composition having excellent adhesion to a member constituting the semiconductor device, such as a semiconductor element, and having both excellent curability and storage stability. Therefore, a highly reliable semiconductor device can be obtained. That is, it is possible to obtain a semiconductor device that has excellent adhesion and suppresses the occurrence of defects such as poor filling.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in the adhesiveness with respect to the member which comprises a semiconductor device, and also can provide the epoxy resin composition excellent in both sclerosis | hardenability and storage stability. Moreover, the semiconductor device formed by sealingly molding a semiconductor element with the said epoxy resin composition is provided.

  The epoxy resin composition of the present invention is an epoxy resin composition that is liquid at room temperature containing an epoxy resin, a curing agent, and a curing accelerator, and the curing agent has three SH groups in one molecule. Including a carboxylic acid ester compound and a tetrahydrophthalic anhydride compound having three hydrocarbon groups in one molecule, wherein the content of the mercaptocarboxylic acid ester compound is 5 to 50% by mass relative to the total amount of the curing agent. It is characterized by being. Here, normal temperature refers to a temperature of about 10 to 30 ° C. That is, the epoxy resin composition is an epoxy resin composition that is liquid at normal temperature, for example, about 25 ° C.

  As said epoxy resin, if the epoxy resin composition in normal temperature turns into a liquid form, it can use without limitation, The well-known epoxy resin used for the epoxy resin for semiconductor sealing can be used. Specifically, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol type epoxy resin such as bisphenol S type epoxy resin, cresol novolac type epoxy resin such as O-cresol novolak type epoxy resin, biphenyl type epoxy, etc. Examples thereof include resins, dicyclopentadiene type epoxy resins, and bromine-containing epoxy resins. Among these, bisphenol type epoxy resins are preferable, and bisphenol A type epoxy resins are more preferable. By using a bisphenol A type epoxy resin as an epoxy resin and using a curing agent described later, in a liquid epoxy resin composition having excellent adhesion to members constituting a semiconductor device, it is excellent in curability and storage stability. A product superior in properties can be obtained. The epoxy resin may be a liquid epoxy resin or a solid epoxy resin, and can be used without limitation. However, since the epoxy resin composition at room temperature must be liquid, Epoxy resin is used. Moreover, as said epoxy resin, said each epoxy resin may be used independently, and may be used in combination of 2 or more type.

  The curing agent reacts with the epoxy resin to cure the epoxy resin composition, specifically, a mercaptocarboxylic acid ester compound having three SH groups in one molecule and one molecule. At least a tetrahydrophthalic anhydride compound having three hydrocarbon groups, and the content of the mercaptocarboxylic acid ester compound is 5 to 50% by mass based on the total amount of the curing agent.

  The mercaptocarboxylic acid ester compound may be a mercaptocarboxylic acid ester compound having three SH groups in one molecule. Specifically, for example, an ester compound composed of mercaptocarboxylic acid and a trivalent or higher valent alcohol compound may be used. The mercaptocarboxylic acid is not particularly limited, and specific examples include mercaptoacetic acid and mercaptopropionic acid. The alcohol compound is not particularly limited as long as it has 3 or more hydroxyl groups. Specifically, for example, 1,2,4-butanetriol, 1,2,3-propanetriol, 1 , 2,5-pentanetriol, 1,2,6-hexanetriol, trimethylolpropane, glycerin, 2-methylpropanetriol, and triol compounds such as 2-methyl-1,2,4-butanetriol, 1,4 -Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol and the like. Among these, a triol compound is preferable for forming a mercaptocarboxylic acid ester compound having three SH groups in one molecule. Further, as the mercaptocarboxylic acid ester compound, for example, a compound represented by the following formula (1) is preferable.

  The tetrahydrophthalic anhydride compound is not particularly limited as long as it is tetrahydrophthalic anhydride having three hydrocarbon groups in one molecule. Specifically, for example, a compound represented by the following formula (2) is preferable.

The content of the mercaptocarboxylic acid ester compound is based on the total amount of the curing agent,
It is 5-50 mass%, and it is preferable that it is 10-30 mass%. When the amount of the mercaptocarboxylic acid ester compound is too small, the adhesion tends to decrease and the curability tends to decrease. Moreover, when there are too many said mercaptocarboxylic-acid ester compounds, there exists a tendency for sclerosis | hardenability to increase too much and for storage stability to fall.

Further, the content of the tetrahydrophthalic anhydride compound is based on the total amount of the curing agent.
It is preferable that it is 50-95 mass%, and it is more preferable that it is 70-90 mass%. When the amount of the tetrahydrophthalic anhydride compound is too small, when the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound are used as a curing agent, the content of the mercaptocarboxylic acid ester compound is excessively increased and the curability is increased. It tends to be too high and storage stability decreases. On the other hand, when the amount of the tetrahydrophthalic anhydride compound is too large, the content of the mercaptocarboxylic acid ester compound becomes too small, the adhesion is lowered, and the curability tends to be lowered.

  Moreover, as said hardening | curing agent, if it contains the said mercapto carboxylic acid ester compound and the said tetrahydro phthalic anhydride compound, hardening | curing agents other than the said mercapto carboxylic acid ester compound and the said tetrahydro phthalic anhydride compound (other hardening | curing agents) ) May be further contained. Examples of the other curing agent include known curing agents. Specifically, for example, hydrocarbons in one molecule such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, pyromellitic anhydride, etc. Acid anhydride curing agents other than tetrahydrophthalic anhydride having three groups, amine curing agents such as diaminodiphenylmethane and metaphenylenediamine, phenolic curing agents such as phenol novolac resin, poly (polycaptane, polysulfide resin, etc.) Examples include mercaptan curing agents.

  Further, the total content of the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound is 80% by mass or more based on the total amount of the curing agent, even when the other curing agent is contained. It is preferable. The curing agent is more preferably composed of the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound. That is, the total content of the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound is more preferably 100% by mass with respect to the total amount of the curing agent. If the total content of the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound is too small, the combined effect of the mercaptocarboxylic acid ester compound and the tetrahydrophthalic anhydride compound cannot be sufficiently exerted, and the semiconductor device There exists a tendency for the epoxy resin composition which was excellent in all the adhesiveness with respect to the member to comprise, sclerosis | hardenability, and storage stability to become difficult to obtain.

  Moreover, it is although it does not specifically limit as content of the said hardening | curing agent, It is preferable that the ratio (hardening agent / epoxy resin) with respect to the said epoxy resin is 0.6-1.2 by an equivalent ratio. When there is too little content of the said hardening | curing agent, sclerosis | hardenability will fall and there exists a tendency for hardening to be insufficient. Moreover, when there is too much content of the said hardening | curing agent, it will not react with an epoxy resin, but the quantity of the hardening | curing agent which remains in hardened | cured material will increase, and there exists a tendency for the reliability of the obtained semiconductor device to fall.

  Moreover, as said hardening accelerator, if it can accelerate | stimulate the hardening reaction of the said epoxy resin and the said hardening | curing agent, it can use without limitation in particular. Specifically, for example, imidazole series such as 2-methylimidazole, 2-ethyl-4-methylimidazole (2E4MZ), 2-phenyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, etc. Compounds, tertiary amines such as 1,8-diazabicyclo (5,4,0) -7-undecene (DBU), and microcapsule type curing accelerators. Among these, imidazole compounds are preferable, and 2E4MZ is more preferable. By using 2E4MZ as the curing agent described above as the curing agent and 2E4MZ as the curing accelerator, the liquid epoxy resin composition having excellent adhesion to the members constituting the semiconductor device is excellent in curability and storage. Excellent stability is obtained. Moreover, the said hardening accelerator may use each said hardening accelerator independently, and may be used in combination of 2 or more type.

  It is preferable that content of the said hardening accelerator is 0.01-10 mass% with respect to the epoxy resin composition whole quantity. When the content of the curing accelerator is too small, the time required for curing becomes longer and workability tends to be lowered. Moreover, when there is too much content of a hardening accelerator, there exists a tendency for the fall of the pot life at normal temperature, and the influence of an impurity ion to be expressed easily.

  Moreover, the said epoxy resin composition may contain thermosetting resins other than the said epoxy resin. Specific examples of the thermosetting resin other than the epoxy resin include a silicone resin, a urethane resin, a polyimide resin, and a phenol resin. In addition, as the thermosetting resin other than the epoxy resin, even if it is liquid or solid, it can be used without limitation, but the epoxy resin composition at room temperature must be liquid, Usually, a liquid thermosetting resin is used. Further, even when a thermosetting resin other than the epoxy resin is contained, the content of the epoxy resin is based on the total content of the epoxy resin and the thermosetting resin other than the epoxy resin. It is preferable that it is 90 mass% or more.

  Moreover, it is preferable that the said epoxy resin composition contains an inorganic filler. By including the inorganic filler, performance such as low thermal expansion and improved workability can be exhibited, and further, raw material costs can be reduced. The inorganic filler is not particularly limited, and a conventionally known inorganic filler can be used. Specific examples include fused silica, crystalline silica, differential silica, alumina, silicon nitride, and magnesia. These may be used alone or in combination of two or more. Among the inorganic fillers, spherical fused silica is preferable as the inorganic filler from the viewpoints of lowering viscosity and improving flow characteristics. Moreover, when the said inorganic filler is spherical, for example, in the case of spherical fused silica, the average particle diameter is preferably 0.2 to 30 μm, and more preferably 0.2 to 5 μm. The average particle diameter can be measured by a laser diffraction scattering method or the like.

  In the epoxy resin composition, as a composition other than the above, conventionally known additives, for example, a coupling agent, a colorant, an antifoaming agent, and a modification, as long as the desired characteristics of the present invention are not impaired. You may add an agent etc. as needed. Specific examples of the coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and the like. These silane coupling agents are mentioned. Examples of the colorant include pigments and dyes such as carbon black.

  The epoxy resin composition has a predetermined content of the epoxy resin, the curing agent, the curing accelerator, and, if necessary, a thermosetting resin other than the epoxy resin, the inorganic filler, the additive, and the like. In such a manner, they are mixed simultaneously or sequentially and mixed with a mixer or the like so that each component is uniformly dispersed, and then kneaded with a roll or a kneader. When mixing or kneading, heat treatment or cooling treatment may be performed as necessary. Moreover, there is no restriction | limiting in particular in the order which mix | blends each said component.

  The semiconductor device of the present invention is obtained by encapsulating a semiconductor element with the epoxy resin composition obtained as described above. Specifically, for example, a semiconductor device obtained by sealing between a semiconductor element such as an IC chip or an LSI chip and a circuit board (interposer) with the epoxy resin composition, a flexible printed wiring board (FPC) Chip-on-film (COF) obtained by mounting a semiconductor element in a semiconductor element mounting region in a circuit formed in (2) and then sealing between the semiconductor element and the FPC with the epoxy resin composition. Examples include a semiconductor device having a structure.

  More specifically, for example, the epoxy resin composition is dispensed in a gap between bumps of a semiconductor element mounted on a circuit pattern surface of a circuit board such as a ceramic substrate or FR grade via a large number of bumps. Apply and fill with. Then, the epoxy resin composition is cured by heating. Thereafter, a post-process or the like for sealing the entire semiconductor element is performed. By doing so, a semiconductor device by flip chip mounting using the epoxy resin composition as a sealing material can be manufactured. The heat curing condition may be not lower than the curing temperature of the epoxy resin composition, but is preferably 120 to 170 ° C. and about 0.5 to 5 hours, for example.

  Specific examples of the semiconductor device include various area array type packages such as BGA (Ball Grid Array) and CSP (Chip Size Package) packages.

  Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

  An epoxy resin composition was prepared by blending, mixing, and kneading each component of the epoxy resin, the curing agent, and the curing accelerator according to a conventional method at a blending ratio (parts by mass) shown in Table 1. In the examples and comparative examples, the following raw materials were used.

Epoxy resin: Bisphenol A type epoxy resin (Epicoat 828 manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 190)
Curing agent 1: Compound represented by the above formula (1) (QX-30, SH equivalent 123 manufactured by Japan Epoxy Resin Co., Ltd.)
Curing agent 2: Compound represented by the above formula (2) (Epicure YH-306 manufactured by Japan Epoxy Resin Co., Ltd., active hydrogen equivalent 238)
Curing accelerator: 2-ethyl-4-methylimidazole (2E4MZ manufactured by Shikoku Kasei Kogyo Co., Ltd.)
Using each epoxy resin composition prepared as described above, evaluation was performed by the following method.

(Pot life)
First, the viscosity (initial viscosity) of the epoxy resin composition immediately after preparing the epoxy resin composition was measured with a B8H viscometer (manufactured by Tokyo Keiki Co., Ltd.). And the time until the viscosity with respect to the said initial viscosity doubled immediately after preparing the said epoxy resin composition was measured as a pot life. Here, the viscosity is a viscosity at 25 ° C.

(Adhesion strength)
A cured product (molded product) in the shape of a truncated cone (pudding) having an upper base diameter of 4 mm, a lower base diameter of 3 mm, and a height of 5 mm on the surface of an alumina ceramic plate, the epoxy resin composition And formed by pudding molding. As molding conditions at this time, the epoxy resin composition coated on the ceramic plate was cured by heating at 80 ° C. for 2 hours.

  Then, the adhesion strength (shear strength) between the formed pudding-shaped molded product and the ceramic plate was measured using a bonding strength tester (DS100 manufactured by Daisy).

(Curing degree)
A test piece obtained by heating the epoxy resin composition at 80 ° C. for 2 hours was measured using a differential scanning calorimeter (DSC) at a heating rate of 10 ° C./min. did. At that time, if the amount of heat was measured, the test piece was evaluated as “uncured”, and if the amount of heat was not measured, the test piece was evaluated as “cured”.

  The results are shown in Table 1.

  As can be seen from Table 1, the mercaptocarboxylic acid compound contains a mercaptocarboxylic acid ester compound having three SH groups in one molecule and a tetrahydrophthalic anhydride compound having three hydrocarbon groups in one molecule as a curing agent. When content of an acid ester compound is 5-50 mass% with respect to the said hardening | curing agent whole quantity (Examples 1-3), when not containing the said mercaptocarboxylic acid ester compound (comparative example 1), the said Compared to the case where the content of the mercaptocarboxylic acid ester compound is less than 5% by mass (Comparative Example 2) and the case where the content of the mercaptocarboxylic acid ester compound exceeds 50% by mass (Comparative Example 3). The pot life was long, the adhesion strength with the substrate was high, and the degree of curing when heated at 80 ° C. for 2 hours was high. Therefore, the mercaptocarboxylic acid ester compound includes a mercaptocarboxylic acid ester compound having three SH groups in one molecule and a tetrahydrophthalic anhydride compound having three hydrocarbon groups in one molecule as a curing agent. When the content of the epoxy resin is 5 to 50% by mass with respect to the total amount of the curing agent, the epoxy resin has excellent adhesion to the members constituting the semiconductor device, and has excellent curability and storage stability. It was found that a composition was obtained. That is, when the amount of the mercaptocarboxylic acid ester compound is too small, the curing is slow and the original low-temperature curability cannot be sufficiently exhibited. On the other hand, when the amount of the mercaptocarboxylic acid ester compound is too large, It was found that the characteristics of the compound were not exhibited at all, life performance was impaired, and further, moisture resistance performance was impaired and adhesion strength was lowered.

Claims (4)

An epoxy resin composition that is liquid at room temperature containing an epoxy resin, a curing agent, and a curing accelerator,
The curing agent includes a mercaptocarboxylic acid ester compound having three SH groups in one molecule and a tetrahydrophthalic anhydride compound having three hydrocarbon groups in one molecule;
The content of the mercaptocarboxylic acid ester compound is based on the total amount of the curing agent,
The epoxy resin composition characterized by being 5-50 mass%. The epoxy resin composition according to claim 1, wherein the mercaptocarboxylic acid ester compound is a compound represented by the following formula (1).

The epoxy resin composition according to claim 1, wherein the tetrahydrophthalic anhydride compound is a compound represented by the following formula (2).

  A semiconductor device obtained by encapsulating a semiconductor element with the epoxy resin composition according to claim 1.