JPH0218413A - Epoxy resin composition and resin sealing-type semiconductor device - Google Patents

Abstract

PURPOSE:To contrive to improve heat resistance and low stress properties by using respectively specified epoxy resins and curing agents in producing an epoxy resin composition from epoxy resins and phenolic hydroxyl group- containing curing agents. CONSTITUTION:In producing an epoxy resin composition from epoxy resins and curing agents containing >=2 phenolic hydroxy groups, one or more epoxy resins of formula I-III (B is group of formula IV; B' is group of formula V; B'' is group of formula VI; Q is >=2C hydrocarbon; Q' is >=1C hydrocarbon; R is H, halogen, etc.; n is 0 or ordinary number) are mixed in the epoxy resin components and/or one or more curing agents of formula VII-IX (A is group of formula X; A' is group of formula XI; A'' is group of formula VI) are mixed into the curing agent components, thus obtaining an epoxy resin capable of providing a highly reliable resin sealing type semiconductor device in sealing semiconductor tips.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to an epoxy resin composition and a resin-encapsulated semiconductor device, and particularly relates to an epoxy resin composition and an epoxy resin composition having excellent heat resistance and low stress properties. The present invention relates to a highly reliable resin-sealed semiconductor device using the same.

(Prior Art) Epoxy resin compositions are widely used to encapsulate integrated circuits (ICs), large-scale integrated circuits (LSIs), semiconductor components such as transistors, electronic components, and other components.

As described above, the encapsulating resin made of a cured epoxy resin composition used to encapsulate semiconductor components, electronic components, etc. is required to have heat resistance to withstand soldering when mounted on a printed circuit board. Regarding this soldering, the method of soldering by solder flow or reflow has become mainstream.

During solder flow or reflow, the sealing resin is exposed to temperatures of 200° C. or higher, sometimes 300° C. or higher, for a short period of time, so it is necessary that cracks or other failures do not occur under these conditions.

Conventionally, as epoxy resin compositions for the above-mentioned uses, those containing a cresol novolac type epoxy resin as a main component and a novolac type phenolic resin as a curing agent have been generally used.

However, the cured product of an epoxy resin composition having such a composition has a glass transition temperature of 200°C or less, and because of insufficient heat resistance, cracks are likely to occur during solder flow or reflow, and sufficient reliability is not achieved. The problem was that I couldn't get it.

In addition, the cured products of conventional epoxy resin compositions have a high elastic modulus, and therefore, when semiconductor chips and the like are encapsulated, the encapsulating resin can be used at high temperatures (e.g., 200°C) and at low temperatures (e.g., -65°C).
), a large thermal stress will be generated between the sealing resin and the semiconductor chip sealed inside, which will cause cracks to occur in the sealing resin and the chip, and also cause damage to the chip surface. This had the disadvantage that cracks in the oxide film and deformation of the aluminum wiring were likely to occur.

(Problems to be Solved by the Invention) As described above, the cured products of conventional epoxy resin compositions have low heat resistance and high thermal stress, and therefore the reliability of resin-encapsulated semiconductor devices obtained using the same is low. The problem was that it was low.

The present invention was made in view of the above problems.
The object of the present invention is to provide a heat-resistant, low-stress epoxy resin composition and a highly reliable resin-sealed semiconductor device using the same.

[Structure of the invention]

(Means for Solving the Problems) The epoxy resin composition of the present invention is an epoxy resin composition containing an epoxy resin and a curing agent having three or more phenolic hydroxyl groups in one molecule as essential components. A) The above epoxy resin is represented by the following formulas [1] to [m] (wherein in the formula [Icol [In], it is represented by (R) 4 , Q is a hydrocarbon group having 2 or more carbon atoms, and Qo is a hydrocarbon group having 1 or more carbon atoms; each R independently represents hydrogen, halogen, or a hydrocarbon group or halogenated hydrocarbon group having 1 or more carbon atoms; n represents an integer of 0 or 1 or more;

), or (B) the curing agent contains at least one of the epoxy resins represented by the following formulas [IV] to [VI] (however, in formulas [■] to [VI], (R) 4 (R)3 (R)4 where Q is a hydrocarbon group having 2 or more carbon atoms, Qo is a hydrocarbon group having 1 or more carbon atoms, and each R is independently hydrogen, halogen, or 1 or more carbon atoms. is a hydrocarbon group or a halogenated hydrocarbon group, and n represents an integer of 0 or 1 or more.

) It is characterized by satisfying at least one of the following two conditions (A) and (B): containing at least one type of curing agent represented by the following.

Further, the resin-sealed semiconductor device of the present invention is characterized in that a semiconductor chip is sealed with the above-mentioned epoxy resin composition.

The present invention will be explained in more detail below.

First, a supplementary explanation will be given of the symbols in the above formulas [1] to [VI]. Q represents a hydrocarbon group having 2 or more carbon atoms,
Specifically, /CH""CH2""CH.

, >cH-(CH2)2-c< Examples include.

Qo represents a hydrocarbon group having one or more carbon atoms, and specifically examples of formula [T] include when R is hydrogen and Q is an ethane residue, when n-0 and -1, etc. It will be done. In the above formula, R is defined similarly to R in formulas [1] to [VI], and is -H, -F.

-C(1,-Br,-(CH2) CHs, (CF
2) n CF 3 (n is O or an integer of 1 or more)
etc. In particular, when R is -(CF2) or CF, the hygroscopicity of the epoxy resin composition decreases, which is effective in preventing cracks during soldering.

Specific examples of the epoxy resins represented by the above formulas [I] to [m] and the curing agents represented by the above formulas [IV] to [VT] include the following.

[I-b] As an example of formula [n], when R is hydrogen, Qo is carbon, and Q is an ethane residue, when n-1, [11-al As an example of formula [m], R is hydrogen, Qo is is carbon, Q is an ethane residue, and n-1. An example of formula [V] is when R is hydrogen, Qo is carbon, and Q is an ethane residue, and when n-1, [I[I -al As an example of formula [IV], when R is hydrogen, Qo is carbon, and Q is an ethane residue, when n-0, [V-al As an example of formula [VI], R is hydrogen, Qo is carbon, When Q is an ethane residue, when n-1 when n-1 H R [IV -b] H [VI-al When using the epoxy resin of the above formulas [1] to [IIl,] If this is cured with a curing agent having two or more phenolic hydroxyl groups in one molecule, a cured product with excellent heat resistance can be obtained.

Moreover, when an epoxy resin is cured using the curing agents of formulas [IV] to [VI] above, a cured product with excellent heat resistance is obtained. Being ignored.

In particular, formula [1] ~ [ml of epoxy resin and formula [IV] ~
By reacting with the curing agent [VI], a cured product with extremely good heat resistance can be obtained.

Note that the epoxy resins of formulas [I] to [II[] and other epoxy resins may be used in combination. On the other hand, the formula [TV1~[V
The curing agent I'l may be used in combination with other curing agents. In addition,
It is preferable to use the epoxy resin and the curing agent after melting and mixing them in advance, and it is further preferable to use the epoxy resin and the curing agent in a uniformly mixed state by melt-mixing the epoxy resin and the curing agent in advance depending on the case.

In the present invention, the epoxy resins used in addition to the epoxy resins of formulas [11 to [ml] are commonly known ones and are not particularly limited. For example, bisphenol type epoxy resin, novolak type epoxy resin, tetrakis(glycidoxyphenyl)ethane, formula [■] (wherein, Q is a hydrocarbon group having 1 or more carbon atoms, and each R is independently hydrogen, halogen, or carbon Glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy Examples include epoxy resins having two or more epoxy resins in one molecule, such as resins, heterocyclic epoxy resins, and halogenated epoxy resins. Among these, particularly preferred epoxy resins are novolac type epoxy resins, epoxy resins represented by the above formula [■], and the like. These epoxy resins may be used alone or in a mixed system of two or more.

Note that the epoxy resin has a chlorine ion content of 1
0 ppm or less, hydrolyzable chlorine content 0.1% by weight
The following are desirable. This is because if more than 10 ppm of chlorine ions or more than 0.1% by weight of hydrolyzable chlorine is contained, the aluminum electrodes of the sealed semiconductor chip are likely to be corroded.

In the present invention, specific examples of curing agents having two or more phenolic hydroxyl groups in one molecule that are used in addition to the curing agents of formulas [IV] to [VI] include phenol novolak resin, cresol novolak resin, etc. Novolac-type phenolic resin, resol-type phenolic resin, bisphenol-type phenolic resin, polyparahydroxystyrene, phenol aralkyl resin, and their halogenated products, formula [■] (wherein, Q is a hydrocarbon having 1 or more carbon atoms) group, each R independently represents hydrogen, halogen, or a hydrocarbon group or halogenated hydrocarbon group having one or more carbon atoms, and n represents an integer of 0 or 1 or more.

These curing agents may be used alone or in a mixed system of two or more. As a curing agent other than the above, it is also possible to use an acid anhydride curing agent and an amine curing agent in combination.

Epoxy resins other than formulas [I] to [m], formulas [IV] to [
The curing agents other than VI] are used in an amount of 80% by weight or less, preferably 50% by weight or less of each component.

Regarding the blending ratio of the curing agent and the epoxy resin, it is desirable to blend the curing agent and the epoxy resin so that the equivalent ratio of the phenolic hydroxyl group to the epoxy group is within the range of 0.5 to 1.5. this is,
This is because outside the above range, the reaction is difficult to occur sufficiently and the properties of the cured product are likely to deteriorate.

It is preferred to use catalysts in these reactions, and among the various catalysts that can be used, the most preferred are organic phosphines, organic phosphine oxytos, and coordination compounds of organic phosphines. By using these catalysts, the properties (shin-shin-sei) of the cured product are improved.

The organic phosphine compound has the formula [IX] R2-P []X] (wherein,
R1 to R9 are hydrogen or a hydrocarbon group, and a portion of the hydrocarbon group may be substituted with a substituent containing another atom. Note that the case where R1-R3 are all hydrogen is excluded. ) is a compound represented by Specific examples include triphenylphosphine, tris(methylphenyl)phosphine, tris(methoxyphenyl)phosphine, tributylphosphine, tricyclohexylphosphine, methyldiphenylphosphine, butylphenylphosphine, diphenylphosphine, phenylphosphine, and the like. R
Examples of organic phosphine compounds in which 1 is an organic group containing an organic phosphine include 1,2-bis(diphenylphosphino)ethane, bis(diphenylphosphino)methane, and the like. Among these, arylphosphine compounds are preferred, and triphenylphosphine, tris(methylphenyl)phosphine, tris(methoxyphenyl)phosphine, and the like are particularly preferred.

The organic phosphine oxyto has the formula [X] (where R1-R1 is hydrogen or a hydrocarbon group, and a part of the hydrocarbon group may be substituted with a substituent containing another atom. -Excluding the case where R1 is entirely hydrogen.) This is a compound represented by: Specifically, triphenylphosphine oxide, tris(methylphenyl)phosphine oxide, tribenzylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, diphenylethylphosphine oxide, phenyldimethylphosphine oxide, diphenyl Phosphine oxyto, dihexylphosphine oxide, tris(chlorophenyl)phosphine oxyto, tris(
Examples include hydroxyphenyl)phosphine oxyto, tris(methoxyphenyl)phosphine oxyto, and the like. Among these, triarylphosphine oxyto such as triphenylphosphine oxyto is preferred.

The coordination compound of organic phosphine has the formula EX] (wherein R1-
R6 is hydrogen, halogen, or a hydrocarbon group, and a portion of the hydrocarbon group may be substituted with a substituent containing another atom.

Note that at least one of R1 to R5 is a hydrocarbon group. M is a boron or aluminum atom. ) with organic phosphine and MR, R1R6
It can be easily obtained by reacting with.

The organic phosphine constituting the coordination compound of organic phosphine includes triphenylphosphine, tris(methylphenyl)phosphine, tribenzylphosphine, trioctylphosphine, tricyclohexylphosphine, diphenylethylphosphine, phenyldimethylphosphine, diphenylphosphine, Dihexylphosphine, phenylphosphine, decylphosphine, tris(chlorophenyl)phosphine, tris(hydroxyphenyl)
Examples include phosphine, tris(methoxyphenyl)phosphine, and the like. Among these, triarylphosphines such as triphenylphosphine are preferred.

MR4R5R6 constituting the coordination compound of organic phosphine
Compounds represented by include boron hydride, aluminum hydride, boron halide, aluminum halide,
Examples include organoboron and organoaluminium.

Examples of organic boron compounds include triphenylboron, tris(ethylphenyl)boron, tribenzylboron, trioctylboron, tricyclohexylboron, diphenylmethylboron, phenyldibutylboron, diphenylboron, dioctylboron, phenylboron, Examples include cyclohexylboron and tris(chlorophenyl)boron.

Examples of the a-organic aluminum compound include aluminum compounds corresponding to the above-mentioned boron compounds, such as triphenylaluminum.

Among these organoboron and organoaluminium compounds, triaryl compounds are preferred.

In the present invention, at least one type or a combination of two or more types of the above organic phosphine, organic phosphine oxyto, and organic phosphine coordination compounds can be used. These amounts are 0.001-'2 of the entire composition.
A range of 0% by weight is preferred.

The epoxy resin composition of the present invention may further contain an inorganic filler, a mold release agent, a flame retardant, a coloring agent, a surface treatment agent for the filler, a low stress imparting agent, and other additives, if necessary.

Inorganic fillers include fused silica, crystalline silica, glass fiber, talc, alumina, calcium silicate, calcium carbonate, barium sulfate, magnesia, silicon nitride,
Generally known materials such as boron nitride can be used.

Examples of mold release agents include natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, esters, and paraffins. Flame retardants include chlorinated paraffins, bromotoluene, hexabromobenzene, and Antimony oxide or the like, carbon black or the like as a coloring agent, and a silane coupling agent as a surface treatment agent for the filler can be used.

When preparing an epoxy resin composition containing the various additives mentioned above as a molding material, - numerically, the raw materials are blended in a predetermined composition ratio, thoroughly mixed with a mixer, and then melt-mixed with a hot roll. treatment or mixing treatment using a kneader or the like.

The resin-sealed semiconductor device according to the present invention can be easily manufactured by sealing a semiconductor chip using the above-mentioned epoxy resin composition. Sealing is most commonly performed by low pressure transfer molding, but sealing by injection molding, compression molding, casting, etc. is also possible. The epoxy resin composition is cured by heating during sealing, and a resin-sealed semiconductor device is finally obtained which is sealed with a cured product of this composition. It is particularly desirable to heat to 150° C. or higher during curing. Further, by performing post-curing at 150 to 300°C for several hours to several tens of hours, properties such as heat resistance of the cured product can be improved. The post-cure temperature is preferably 170°C or higher, more preferably 200°C or higher, and the post-cure time is preferably 3-1
It is 6 hours.

(Example) The present invention will be explained in detail below.

Formula [1-al, [1-b], [n-al, [II[-a
Epoxy resins of the formula [IV-al, [IV-b], [V-al, [VI-
Curing agent represented by al, Phenol novolac resin curing agent (number of hydroxyl groups per molecule is 5) Bisphenol A (number of hydroxyl groups per molecule is 2) Triphenylphosphine (curing accelerator A) Triphenylphosphine oxyto (Curing accelerator B) Triphenylphosphine triphenylboron complex (Curing accelerator C) 1,8-diaza-bicyclo(5,4,0) undecene (
Curing accelerator D) was blended into the composition (parts by weight) shown in Table 1, and other ingredients included 700 parts of fused silica powder (filler), 4 parts of carnauba wax (mold release agent), and carbon black (coloring agent). ) 4 parts,
After adding 4 parts of γ-glycidoxypropyltrimethoxysilane (silane coupling agent) and mixing with a mixer, kneading with a heating roll was performed to obtain transfer molding materials for Examples 1 to 13 and Comparative Examples 1 to 3. An epoxy resin composition was prepared.

Using these epoxy resin compositions, test pieces for evaluating resin characteristics were prepared by transfer molding. Further, using these epoxy resin compositions, an MO8 type integrated circuit was sealed by transfer molding to produce a resin-sealed semiconductor device for evaluation.

For molding, epoxy resin heated to 90°C with a high-frequency preheater was molded at 170°C for 2 minutes, and then molded at 200°C for 8 minutes.
This was done by post-curing for an hour. The size of the encapsulated semiconductor chip is lO+5m×12+ms, and the molded resin package is a flat package with a thickness of 2.0 fins.

The following evaluations were performed using these samples.

(a) The dynamic viscoelasticity of the resin test piece was measured to determine the glass transition point.

(b) The bending strength at 200°C of the resin test piece was determined at t-1.

(C) The flexural modulus of the resin test piece at 25°C was measured.

(d) A thermal cycle test was conducted on 820 resin packages. In the heat cycle test, the package was exposed to temperatures of -65° C. and 200° C. for 30 minutes 100 times alternately, and then the package was cut to examine whether resin cracks had occurred inside.

(e) Reflow soldering was performed on 820 resin packages at 215° C. using the vapor phase (VPS) method, and it was examined whether resin cracks were observed on the appearance of the packages.

(“) Regarding the resin package after the above vPS ends, 1.
A moisture resistance test was conducted using a pressure compression method at 21'C and 12 atmospheres, and the occurrence of corrosion defects in the semiconductor chip after 200 hours was investigated.

The above evaluation results are summarized and listed in Table 1.

[Effects of the Invention] As is clear from the above results, the epoxy resin composition of the present invention has excellent heat resistance, and the reliability of resin-sealed semiconductor devices obtained by sealing semiconductor chips using the epoxy resin composition is high. Its properties are high, and therefore its industrial value is great.

Claims (2)

[Claims] (1) In an epoxy resin composition containing an epoxy resin and a curing agent having two or more phenolic hydroxyl groups in one molecule as essential components, (A) the epoxy resin has the following formulas [I] to [III ] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ I ] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [III] (However, formulas [ I ] ~ [ III ], B is represented by ▲There are mathematical formulas, chemical formulas, tables, etc.▼ B' is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ B'' is ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and Q is a carbon atom. 2 or more hydrocarbon groups, Q' is a hydrocarbon group with 1 or more carbon atoms, each R is independently hydrogen, halogen, or a hydrocarbon group or halogenated hydrocarbon group with 1 or more carbon atoms, n is 0 or 1 or more (B) The curing agent has the following formulas [IV] to [VI] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [IV] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [V] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [VI] (However, in formulas [IV] to [VI], A is ▲ mathematical formulas, chemical formulas, tables, etc. etc. ▼ A′ is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ A″ is ▲ There are ▲ Mathematical formulas, chemical formulas, tables, etc. ▼ , Q is a hydrocarbon group with 2 or more carbon atoms, and Q′ is carbon A curing agent represented by a hydrocarbon group having one or more atoms, each R independently representing hydrogen, halogen, or a hydrocarbon group or halogenated hydrocarbon group having one or more carbon atoms, and n representing an integer of 0 or 1 or more. An epoxy resin composition that satisfies at least one of the two conditions (A) and (B), containing at least one of the following. (2) A resin-sealed semiconductor device, characterized in that a semiconductor chip is sealed with the epoxy resin composition according to claim (1).