JPH0750760B2 - Resin molding material for semiconductor encapsulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin molding material for semiconductor encapsulation. More specifically, the present invention is excellent in heat dissipation,
The present invention also relates to a resin molding material for semiconductor encapsulation having improved moldability.

(Prior Art) As a resin molding material for encapsulating a semiconductor element, a material containing an epoxy resin as a main component has been widely used from the viewpoint of performance such as moisture resistance and heat resistance and price. In recent years, along with the high density and high integration of semiconductor elements, the thermal radiation property is improved to reduce the thermal fatigue due to heat generation of the elements, and the thermal stress generated between the semiconductor element and the sealing resin is reduced. It has become necessary to improve moldability and moisture resistance reliability.

In order to improve thermal radiation properties and reduce stress associated with the sealing of such semiconductor elements, generally, a filler such as crystalline silica or alumina has been blended with a sealing resin such as an epoxy resin. ing. Various attempts have also been proposed for blending these fillers.

For example, as such an attempt, compound silica whose surface is treated with alkoxysilanes or titanates for improving crack resistance and moisture resistance (JP-A-62-14).
9743) (JP-A-61-296020) and a method of mixing aluminum hydroxide and red phosphorus powder surface-treated with aluminum hydroxide into an epoxy resin (JP-A-61-276816).

In addition, the inventors of the present invention have already proposed to use a silicon nitride filler capable of realizing higher heat dissipation and lower stress than conventional fillers such as crystalline silica and alumina. There is.

(Problems to be Solved by the Invention) However, when these fillers are filled in a large proportion in the molding material for sealing in order to improve heat dissipation, the viscosity of the molding material for sealing increases. There is a problem of deterioration of moldability such as deterioration of fluidity, deformation of wire, fraying or unfilled portion.

Therefore, in reality, it is not possible to satisfy both the improvement of heat dissipation by filling the filler and the good moldability of the sealing resin molding material.

The present invention has been made in view of the circumstances as described above, and improves the drawbacks of conventional molding materials for semiconductor encapsulation, has excellent heat dissipation of encapsulation, and has a low viscosity and good moldability. The object is to provide a resin molding material for semiconductor encapsulation.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention has a thermal conductivity of 150 × 10 ⁻⁴ cal / cm · sec · ° C. or more having a surface silanol group alkoxylated with alcohol. Provided is a resin molding material for semiconductor encapsulation, which is characterized by containing silicon nitride.

That is, the present invention improves the thermal discharge property of semiconductor device encapsulation, and uses silicon nitride having a silanol group (-Si-OH) on its surface as a filler in order to achieve low stress, and uses a surface silanol group. The alkoxylation with alcohol was made based on the finding that the viscosity of the molding material for sealing is lowered and the moldability is improved.

That is, the silicon nitride used in the present invention has a silanol group on its surface as described above, and the silanol group is alkoxylated with an alcohol.

The silanol group in this case may be introduced by subjecting the surface to a predetermined reaction, or may be generated by simply leaving it in the air. For example, in the case of silicon nitride, it reacts with oxygen and water in the air and its surface is covered with SiO ₂ .

Si ₃ N ₄ + 3O ₂ → 3SiO ₂ + N ₂ Si ₃ N ₄ + 6H ₂ O → 3SiO ₂ + 4NH ₃ The SiO _{2 on} the surface of this silicon nitride further reacts with water in the air to form silanol groups (-SiOH). To do. Silicon nitride is
Thus, it is used in the present invention as an inorganic substrate having a surface silanol group. When these are used, the entire amount thereof may be silicon nitride or the like having a silanol group on the surface, or may be used in combination with another inorganic base material.

Moreover, in the present invention, the silicon nitride having a silanol group alkoxylated with alcohol has a thermal conductivity of 150 × 10 ⁻⁴ cal / cm · sec · ° C. or more. By using a material that satisfies the condition of this thermal conductivity, it is possible to improve the heat dissipation of the sealing.

If the thermal conductivity is less than 150 × 10 ^-4 cal / cm ・ sec ・ ° C,
The heat dissipation of the encapsulant is not satisfactory.

Further, as the silicon nitride, one having a low magnetic content is preferable in order to prevent the occurrence of leakage failure in the sealing. Especially, it is preferable that the content is about 200 ppm or less.

The particle size of silicon nitride is preferably about 1 to 50 μm.

The type of alcohol used for the alkoxylation of the silanol group on the surface is not particularly limited, and ethanol, propanol, isopropanol, pentanol, octanol, butanol, isobutanol having no substituent such as a functional group or an unsaturated group is used. , T-butanol and the like can be preferably used.

The reaction conditions can be appropriately determined according to the characteristics of the sealing material used, the type of alcohol, and the like. For example, several percent of lower alcohol may be allowed to act on the silicon nitride at room temperature to 250 ° C. for about 2 to 20 hours depending on the progress of the reaction. In that case, the degree of progress of the reaction depends on the amount of heat loss, FT-IR, ESCA, and the oil phase when the reacted silicon nitride is placed in a two-phase bath of an oil phase such as n-hexane and an aqueous phase. It can be evaluated by a method such as whether or not it floats on the interface with the aqueous phase (if the alkoxylation has proceeded sufficiently, it floats on the interface).

As the base resin of the molding material for semiconductor encapsulation of the present invention, various known epoxy resins known to have good performance such as moisture resistance and heat resistance can be appropriately used. For example, as an epoxy resin,
Examples thereof include novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin and halogenated epoxy resin.

Further, as the curing agent, those conventionally used such as novolac type phenol resin can be used. In particular, as the novolac type phenol resin, one having two or more phenolic hydroxyl groups in one molecule can be exemplified as a suitable curing agent.

As described above, the molding material for semiconductor encapsulation of the present invention is a semiconductor encapsulating composition containing a conventional epoxy resin or the like as a resin component, and has a thermal conductivity of 150 when the surface is alkoxylated with alcohol as a filler. × 10 ^-4 cal / cm ・ sec ・ ℃
Although the above-mentioned silicon nitride is contained, various other additives may be contained as long as the characteristics of the sealing resin are not impaired. For example, a silicone-based modifier, a flame retardant, a curing accelerator, a release agent, a colorant, a filler and the like can be appropriately blended according to the type and application of the semiconductor element.

Further, as a method for sealing a semiconductor using the semiconductor sealing molding material of the present invention, a method similar to the conventional method can be appropriately adopted depending on the type of the semiconductor element to be sealed.

(Function) The molding material for semiconductor encapsulation of the present invention uses the silicon nitride having the surface of the inorganic substrate alkoxylated with alcohol and having a thermal conductivity of 150 × 10 ⁻⁴ cal / cm · sec · ° C. or more. Therefore, even if this silicon nitride is filled at a high content rate in order to improve the heat dissipation of the semiconductor encapsulation and reduce the stress, it is necessary to prevent the molding material from becoming highly viscous and the fluidity from decreasing. You can In addition, it can be made excellent in heat dissipation and low stress.

(Example) Hereinafter, the molding material for semiconductor encapsulation of the present invention will be specifically described with reference to examples.

Example 1 100 parts by weight of a cresol novolac type epoxy resin was mixed with a phenol novolac type curing agent as a curing agent, and as a filler, silicon nitride whose surface was ethoxylated by reaction with ethanol (heat conductivity 170 × 10 ⁻⁴ cal / cm ・ sec ・
70% by weight was mixed to obtain a molding material for semiconductor encapsulation. Then, the semiconductor element was sealed with this molding material, and the thermal conductivity after the sealing, the melt viscosity at 150 ° C., the spiral flow, the wire deformation, and the moldability were evaluated.

In this case, as a semiconductor element for evaluating wire deformation and formability, TEG 16DI for moisture resistance evaluation manufactured by Matsushita Electric Works, Ltd.
A P Al standard device was used.

The evaluation results are shown in Table 1. Both heat dissipation and moldability were excellent.

Example 2 Silicon nitride (thermal conductivity 180 × 10 ⁻⁴ cal / cm · sec · ° C.) whose surface was ethoxylated with ethanol was used as a filler.
wt% was added, a molding material for semiconductor encapsulation was prepared in the same manner as in Example 1, the semiconductor element was encapsulated, and its properties were evaluated.

The results are shown in Table 1.

Similar to Example 1, the heat dissipation was excellent, the melt viscosity was low, and the spiral flow, wire deformation, and moldability were good.

Comparative Example 1 Alumina having no silanol group on the surface (heat conductivity of 170
(× 10 ⁻⁴ cal / cm · sec · ° C.) was treated with ethanol, and 80 wt% of this was added as a filler to prepare a molding material for semiconductor encapsulation in the same manner as in Example 1 and encapsulating a semiconductor element. Its properties were evaluated. In this case, no ethoxy group was formed on the surface of alumina.

The results are shown in Table 1.

Moldability was not satisfactory.

Comparative Example 2 As a filler, crystalline silica having a silanol group on the surface and ethoxylated with ethanol (heat conductivity 140 × 1
80 wt% (0 ⁻⁴ cal / cm · sec · ° C.) was added to prepare a semiconductor encapsulating molding material in the same manner as in Example 1, and the semiconductor element was encapsulated to evaluate its properties.

The results are shown in Table 1. The melt viscosity was high, and the spiral flow and wire deformation were inferior to the examples.

Comparative Example 3 As a filler, 80 wt% of silicon nitride having a silanol group on the surface but not ethoxylated with ethanol (thermal conductivity 180 × 10 ⁻⁴ cal / cm · sec · ° C.) was added, and Example 1 was added. Similarly to the above, a molding material for semiconductor encapsulation was prepared, the semiconductor element was encapsulated, and its properties were evaluated.

The results are shown in Table 1. Moldability was remarkably inferior. The molding was unfilled.

Comparative Example 4 As a filler, alumina having no silanol group on the surface (thermal conductivity 170 × 10 ⁻⁴ cal / cm · sec · ° C.) was used as it was.
wt% was added, a molding material for semiconductor encapsulation was prepared in the same manner as in Example 1, the semiconductor element was encapsulated, and its properties were evaluated.
In this case, no ethoxy group was formed on the surface of alumina.

The results are shown in Table 1.

Also in this case, the moldability was completely insufficient, and voids and scrapes were generated during molding.

Comparative Example 5 In Example 1, the thermal conductivity was 145 × 10 ⁻⁴ cal / cm · sec ·
Similarly, the semiconductor element is sealed using silicon nitride at ℃,
The performance was evaluated. As shown in Table 1, the heat dissipation property was extremely poor.

Comparative Example 6 A semiconductor element was sealed in the same manner as in Example 1 except that the surface of silicon nitride having a thermal conductivity of 145 × 10 ⁻⁴ cal / cm · sec · ° C., which was not ethoxylated with ethanol, was used as a filler to seal the semiconductor element, and the performance was evaluated. Was evaluated. As shown in Table 1, both heat dissipation and moldability were inferior.

Comparative Example 7 In Example 1, a molding material for sealing was prepared using silicon nitride whose surface was treated with ethoxysilane. Example 1
The semiconductor element was sealed in the same manner as in (1) and its performance was evaluated.

As shown in Table 1, both heat dissipation and moldability were inferior.

Example 3 Propoxylated silicon nitride was used in the same manner as in Example 1 except that ethanol was replaced with propanol (thermal conductivity 160 × 10 ⁻⁴ c).
Al / cm · sec · ° C) was used as a filler to prepare a molding compound for semiconductor encapsulation, which was then sealed.

Both the heat dissipation property and the moldability were better than those of the comparative example.

Example 4 Pentanol was used instead of ethanol in the same manner as in Example 2 to form pentanoylated silicon nitride (thermal conductivity: 180 × 10 ⁻⁴ c
al / cm · sec · ° C) was used as a filler and resin-sealed.

Similarly, the heat dissipation and moldability were good.

From the above examples, it was confirmed that the semiconductor encapsulations of the examples of the present invention have high heat dissipation properties, low melt viscosity, and excellent spiral flow, wire deformation, and moldability.

(Effect of the Invention) With the molding material for semiconductor element encapsulation of the present invention, the heat dissipation of the semiconductor encapsulation can be improved and the moldability can be made excellent. Therefore, by using the molding material for semiconductor element encapsulation of the present invention, good resin encapsulation of power transistor devices and highly integrated LSIs becomes possible.

Claims (1)

[Claims] 1. A thermal conductivity of epoxy resin having a surface silanol group alkoxylated with alcohol to 150 × 1.
A resin molding material for semiconductor encapsulation, which is characterized by being compounded with silicon nitride of 0 ^-4 cal / cm · sec · ° C or higher.