JP2654093B2 - Resin-sealed semiconductor device - Google Patents

Description

The present invention relates to a resin-sealed semiconductor device sealed with an epoxy resin composition, and particularly to a heat-resistant, low-stress, and The present invention relates to a highly reliable resin-encapsulated semiconductor device.

(Prior Art) Epoxy resin compositions are widely used for encapsulating semiconductor parts such as integrated circuits (IC), large-scale integrated circuits (LSI), transistors, electronic parts and other parts.

As described above, a sealing resin made of a cured product of an epoxy resin composition in which a semiconductor component, an electronic component, or the like is sealed is required to withstand soldering when mounted on a print base. Regarding this soldering, a method of soldering by solder flow or reflow has become mainstream. And at the time of soldering, the sealing resin
Due to short-term exposure to temperatures of 200 ° C. or higher, sometimes 300 ° C. or higher, it is necessary that cracks and other failures do not occur under these conditions.

Conventionally, as the epoxy resin composition for the use described above,
Cresol novolak type epoxy resin as the main component,
What contains a novolak type phenol resin as a curing agent has been generally used. However, a cured product of the epoxy resin composition having such a composition has a glass transition temperature of 200 ° C. or lower and has insufficient heat resistance, so that it tends to generate clerk during solder flow or reflow, and has sufficient reliability. There was a problem that can not be obtained.

In addition, the cured product of the conventional epoxy resin composition has a high elastic modulus, so that a high temperature (eg, 200 ° C.) and a low temperature (eg, −65 ° C.)
When a thermal stress is applied, a large thermal stress is generated between the sealing resin and the semiconductor chip sealed therein, so that the sealing resin and the chip are easily cracked, and the oxide film on the chip surface Cracks and deformation of the aluminum wiring are likely to occur.

(Problems to be Solved by the Invention) As described above, the cured product of the conventional epoxy resin composition has low heat resistance and large thermal stress, and therefore, the reliability of the resin-encapsulated semiconductor device obtained by using the same is low. There was a problem that it was low.

The present invention has been made in view of the above problems, and has as its object to provide a resin-sealed semiconductor device having heat resistance, low stress, and high reliability.

[Structure of the Invention] (Means for Solving the Problems) The resin-encapsulated semiconductor device of the present invention is a resin-encapsulated semiconductor device in which a semiconductor device is encapsulated with a cured product of an epoxy resin composition. Is the formula [I] (Wherein, Q represents a hydrocarbon group having 1 or more carbon atoms, each R independently represents hydrogen, halogen, a hydrocarbon group having 1 or more carbon atoms, or a halogenated hydrocarbon group, and n represents 0 or an integer of 1 or more. And a reaction product of an epoxy compound represented by the formula (1) with a curing agent having two or more phenolic hydroxyl groups in one molecule, and an organic phosphine oxide.

 Hereinafter, the present invention will be described in more detail.

In the present invention, the essential components constituting the cured product of the epoxy resin composition are as follows: (a) Formula [I] (Wherein, Q represents a hydrocarbon group having 1 or more carbon atoms, each R independently represents hydrogen, halogen, a hydrocarbon group having 1 or more carbon atoms, or a halogenated hydrocarbon group, and n represents 0 or an integer of 1 or more. (B) a curing agent having two or more phenolic hydroxyl groups in one molecule, and (c) an organic phosphine oxide. Of these components, (a) and (b) are wholly or partially reacted to form a main component of a cured product of the epoxy resin composition.

In the present invention, examples of the curing agent of the component (b) that reacts with the epoxy compound of the component (a) include a novolak resin, a resol resin, a polyhydroxystyrene, a phenol aralkyl resin, and a polyhydric phenol compound, and more specifically. For example, a phenol novolak resin, a cresol novolak resin, a tert-butylphenol novolak resin, a novolak phenol resin such as a nonylphenol novolak resin, a resol phenol resin,
Examples include polyhydroxystyrene such as polyparahydroxystyrene, bisphenol A, tris (hydroxyphenyl) methane and the like, and halides of these compounds. Among these, a novolak type phenol resin, a phenol aralkyl resin, polyhydroxystyrene, and tris (hydroxyphenol) methane are preferred. These curing agents are used alone or in a mixture of two or more.

In the present invention, the cured product as the sealing resin is the component (a)
And the phenolic hydroxyl group of component (b). When all or some of these functional groups react, a cured product having a three-dimensional network structure is obtained.

It is preferable that the mixing ratio of the component (a) and the component (b) is determined so that the ratio of the phenolic hydroxyl group to the epoxy group is in the range of 0.5 to 1.5. The reason is that, when the mixing ratio is less than 0.5 or exceeds 1.5, the number of unreacted functional groups increases, and the properties and reliability of the cured product decrease. When an epoxy resin other than the component (a) is blended, the number of phenolic hydroxyl groups is preferably in the range of 0.5 to 1.5 with respect to the total number of the epoxy groups other than the component (a).

In the present invention, the cured product of the epoxy resin composition includes:
The third component includes (c) an organic phosphine oxide.

The organic phosphine oxide has the formula [II] (In the formula, R _{1 to} R ₃ are hydrogen or a hydrocarbon group, and a part of the hydrocarbon group may be substituted with a substituent containing another atom.
Except when all of R _{1 to} R ₃ are hydrogen. ). Specifically, triphenyl phosphine oxide, tris (methylphenyl) phosphine oxide, tribenzyl phosphine oxide, trioctyl phosphine oxide, tricyclohexyl phosphine oxide, diphenylethyl phosphine oxide,
Examples include phenyldimethylphosphine oxide, diphenylphosphine oxide, dihexylphosphine oxide, phenylphosphine oxide, tris (chlorophenyl) phosphine oxide, tris (hydroxyphenyl) phosphine oxide, and tris (methoxyphenyl) phosphine oxide. Of these, triarylphosphine oxides such as triphenylphosphine oxide are preferred.

The coordination compound of the organic phosphine has the formula [III] (Wherein, R _{1 to} R ₆ are hydrogen, halogen, or a hydrocarbon group, and part of the hydrocarbon group may be substituted with a substituent containing another atom. In addition, at least _one of R _{1 to} R ₃ One is a hydrocarbon group, and M is a boron or aluminum atom.) This compound is easily obtained by reacting an organic phosphine with MR ₄ R ₅ R ₆ .

Examples of the organic phosphine constituting the coordination compound of the organic phosphine include triphenylphosphone, tris (methylphenyl) phosphine, tribenzylphosphine, trioctylphosphine, tricyclohexylphosphine,
Diphenylethylphosphine, phenyldimethylphosphine, diphenylphosphine, dihexylphosphine,
Examples include phenylphosphine, decylphosphine, tris (chlorophenyl) phosphine, tris (hydroxyphenyl) phosphine, and tris (methoxyphenyl) phosphine. Of these, triarylphosphines such as triphenylphosphine are preferred.

Examples of the compound represented by MR ₄ R ₅ R ₆ constituting the coordination compound of the organic phosphine include borohydride, aluminum hydride, boron halide, aluminum halide, organic boron, and organic aluminum.

Examples of the organic boron compound include triphenyl boron, tris (ethylphenyl) boron, tribenzyl boron,
Trioctyl boron, tricyclohexyl boron, diphenylmethyl boron, phenyl dibutyl boron, diphenyl boron, phenyl dibutyl boron, diphenyl boron, dioctyl boron, phenyl boron, cyclohexyl boron, tris (chlorophenyl) boron and the like.

Examples of the organoaluminum compound include an aluminum compound corresponding to the above boron compound, such as triphenylaluminum.

Of these organoboron and organoaluminum compounds, triaryl compounds are preferred.

In the present invention, one or more components (c) may be contained. These contents are 0.001-1% of the whole cured product.
A range of 0% by weight is preferred.

In the present invention, as the epoxy resin component, in addition to the component (a), another epoxy resin may be contained as necessary. Other epoxy resins, for example, bisphenol type epoxy resin, glycidyl ether type epoxy resin such as novolak type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, Epoxy resins having two or more epoxy groups in one molecule, such as halogenated epoxy resins, may be mentioned.

The cured product according to the present invention may further contain, if necessary, a curing agent other than the component (b), an inorganic filler, a release agent, a flame retardant, a coloring agent, a surface treatment agent for the filler, and a low stress applying agent. Etc. may be contained.

As other curing agents that can be contained in addition to the component (b), those generally known such as acid anhydride curing agents and amine curing agents can be mentioned.

As the inorganic filler, fused silica, crystalline silica,
Commonly known materials such as glass fiber, talc, alumina, calcium silicate, calcium carbonate, barium sulfate, magnesia, silicon nitride, and boron nitride are exemplified.

Examples of the release agent include natural waxes, synthetic waxes, metal salts of straight-chain fatty acids, acid amides, esters, and paraffins. Examples of the flame retardant include chlorinated paraffin, bromtriene, hexabromobenzene, Coloring agents such as antimony oxide and carbon black
Examples of the surface treatment agent for the filler include a silane coupling agent.

The resin-encapsulated semiconductor device according to the present invention can be easily manufactured by encapsulating a semiconductor chip using the 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 at the time of sealing, and finally, a resin-sealed semiconductor device sealed with a cured product of this composition is obtained. During curing, it is particularly desirable to heat to 150 ° C. or higher. Also, several hours at 150-300 ° C
By performing post-curing for 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 more, more preferably 200 ° C. or more, and the post cure time is preferably 3 to 16 hours.

(Examples) Hereinafter, the present invention will be described in more detail based on examples.

Examples 1 to 9 and Comparative Examples 1 to 4 A resin-sealed semiconductor device in which a semiconductor device is sealed with a cured product of an epoxy resin composition (Examples 1 to 9)
9, Comparative Examples 1 to 4) were produced. The cured product contains the following components.

-Epoxy resins A to C: Formula [I] Where R is hydrogen. Epoxy resin A is a compound of n = 0. Epoxy resin B is a compound of n = 1. Epoxy resin C is a compound of n = 2. Epoxy resin D ... cresol novolak having an epoxy equivalent of 200. Type epoxy resin Curing agent A: Phenol novolak resin having a number average molecular weight of 800 Curing agent B: Cresol novolak resin having a number average molecular weight of 2,000 Curing agent C: Tris (hydroxyphenyl) methane Organic phosphine oxide A: Triphenylphosphine oxide Organic phosphine oxide B ... Tris (methylphenyl) phosphine oxide Configuration compound A ... Triphenylphosphine / triphenylboron coordination compound Coordination compound B: Triphenylphosphine / triphenylaluminum coordination compound Table 1 shows the contents of the components (A) to (C) contained in each cured product. However, in the cured product, all or a part of the epoxy compound of the component and the curing agent of the component have reacted to form a crosslinked polymer.

The cured product contains 700 parts of fused silica (filler), 20 parts of a flame retardant, a release agent, a colorant, a surface treatment agent, and the like as other components shown in Table 1. I have.

The resin-encapsulated semiconductor device is prepared by using an epoxy resin composition as described below, and encapsulating the MOS integrated circuit by resin using a transfer molding method, and the semiconductor encapsulated with the cured epoxy resin composition. The device was obtained. In addition, a molded cured product for an evaluation test was similarly produced by a transfer molding method.

Here, the transfer molding was performed by molding the epoxy resin composition heated to 90 ° C. with a high frequency preheater at 170 ° C. for 3 minutes, and further post-curing at 200 ° C. for 8 hours. The size of the sealed semiconductor chip is 10 × 12
mm, the molded resin package is a flat package type with a thickness of 2 mm.

Next, the following evaluation tests were performed on each molded cured product and each resin-sealed semiconductor device.

(A) From the measured value of dynamic viscoelasticity, the glass moving point of the molded and cured product was determined.

(B) The bending strength of the cured product was measured at 200 ° C.

(C) The bending elastic modulus of the cured product was measured at 25 ° C.

(D) For each of the 20 resin-encapsulated semiconductor devices, -65 ° C
A heat cycle test was performed by alternately exposing to 200 ° C. 100 times for 30 minutes each. After the test, the package was cut, and it was examined whether or not a resin crack had occurred inside.

(E) Reflow soldering was performed on each of the 20 resin-encapsulated semiconductor devices at 215 ° C. by a vapor phase (VPS) method, and it was examined whether or not resin cracks were observed in the package appearance.

(F) A moisture resistance test was performed on each of the 20 resin-encapsulated semiconductor devices after completion of the VPS by a pressure cooker method at 121 ° C. and 2 atm, and the occurrence of corrosion defects in the semiconductor chips after 200 hours was examined.

 These evaluation results are also shown in Table 1.

[Effects of the Invention] As is clear from the above results, the cured product of the epoxy resin composition according to the present invention has excellent heat resistance, and is obtained by sealing a semiconductor chip using this. The reliability of a semiconductor device is high, and its industrial value is great.

Claims (1)

(57) [Claims] 1. A resin-sealed semiconductor device in which a semiconductor device is sealed with a cured product of an epoxy resin composition, wherein the cured product is represented by the formula [I] (Wherein, Q represents a hydrocarbon group having 1 or more carbon atoms, each R independently represents hydrogen, halogen, a hydrocarbon group having 1 or more carbon atoms, or a halogenated hydrocarbon group, and n represents 0 or an integer of 1 or more. A resin-encapsulated semiconductor device comprising: a reaction product of an epoxy compound represented by the formula (1) with a curing agent having two or more phenolic hydroxyl groups in one molecule; and an organic phosphine oxide.