JPS58102546A - Resin sealed semiconductor device - Google Patents

Abstract

PURPOSE:To omit an organic film process, by using resin for sealing wherein the impalpable powder of SiO2, with less content of radioactive isotope serving as an alpha ray source, is used as filler. CONSTITUTION:With SiCl4, with less content of radioactive isotope serving as the alpha ray source, as the raw material, a mass of SiO2 is produced by a hydrolysis due to oxyhydrogen flame or an oxidation due to plasma flame. This is ground into impalpable powder, and the distribution of grain diameters is made uniform, thereafter a purification process for removing impurity ions is performed, and accordingly SiO2 impalpable powder for filling can be obtained. When this impalpable SiO2 powder, epoxy resin and additives such as hardener, catalyst or carbon black for coloring are mixed and milled so that the SiO2 impalpable powder is 70wt%, the epoxy resin for sealing mixed with SiO2 can be obtained. The accumulated number of alpha ray generation for this epoxy resin for sealing mixed with SiO2 is reduced down to approx. 1/5 of the number of that of the epoxy resin for sealing mixed with silica which is conventionally used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin-sealed semiconductor device, and particularly to a resin for encapsulating a semiconductor chip (hereinafter abbreviated as "sealing resin").
It is related to.

Usually, in resin-sealed semiconductor devices, the encapsulating resin is
Epoxy resin, silicone resin, etc. are used.

However, the thermal expansion coefficient of these encapsulating resins is larger than that of the semiconductor chip, and the thermal conductivity of these encapsulating resins is low, so it is difficult to efficiently transfer the heat generated during the operation of the semiconductor chip to the outside. It is not easy to dissipate, and the temperature rise caused by this generated heat causes thermal stress due to the difference in thermal expansion coefficient between these encapsulating resins and the semiconductor chip, and this thermal stress causes these encapsulating resins to If damaged, the electrical characteristics of the semiconductor chip may deteriorate and reliability may decrease. In order to prevent this, a sealing resin is required that has a small thermal expansion coefficient, a large thermal conductivity, and a high mechanical strength. In order to satisfy this requirement, conventionally, sealing resins have been mixed with a few weight percent to 80 weight percent of fine powder of natural crystalline silica or fine powder of fused silica obtained by regenerating natural crystalline silica by high temperature melting as a filler. (hereinafter referred to as "silica-containing sealing resin") was used.

In recent years, semiconductor devices, especially large-scale semiconductor memory integrated circuit devices (hereinafter referred to as BN memories), have become more densely integrated, and as a result, the spacing between memory cells has become smaller and the capacity of the memory cells has become smaller. Therefore, α that exists in nature
A soft error phenomenon in which the memory of a memory cell is reversed due to a line has been observed for a while.By the way, in conventional resin-encapsulated LSI memories that use silica-containing encapsulation resin, fine powder of natural crystalline silica or fused silica is used. Uranium (U), which is a source of alpha rays,
Since it contains radioactive isotopes such as lithium (t), there is a risk that soft errors may occur due to alpha rays from these radioactive isotopes. In order to suppress the occurrence of this soft error, the LSI memory is
There is a drawback in that an organic film such as polyimide resin that attenuates the energy of alpha rays from radioisotopes must be formed on the surface of the semiconductor chip of the I-memory.

This invention was made in view of the above-mentioned drawbacks of Vcs, and α
Silicon dioxide (sto
By using the 5102-containing sealing resin in which the fine powder of 2) is mixed as a filler, it is possible to omit or simplify the process of forming an organic film that attenuates the energy of the A-ray on the surface of the semiconductor chip. The purpose of this invention is to provide a resin-sealed semiconductor device with a low radioisotope content.
Using tc1!4) as a raw material, 51o2 lumps are produced by hydrolysis using an oxyhydrogen flame as shown in the following formula [1] or oxidation using a plasma flame as shown in the following [mouth] formula.

5iO14+ 02 + 2H2--5i02 + 4
HC1----(DSiaV4 + o2 -810
2 + 20/2---(11) The 8102 lump thus produced is ground into 8102 fine powder, and this 5to2
After adjusting the particle size distribution of the powder, this 5to2 fine powder is subjected to a purification treatment to remove impurity ions, etc., to obtain 8102 fine powder for filler.

The 5102 fine powder thus obtained, an epoxy resin, and additives such as a curing agent, a catalyst, and carbon black for coloring were mixed with the 8102 fine powder in an amount of 70'N.

-cent, the 5102-containing sealing epoxy resin used in this example is obtained.

The figure shows an example of the relationship between the cumulative number of alpha rays generated and the sub-time period of this 8102-containing sealing epoxy resin, measured using a low background alpha ray measuring device.

In the figure, the elongated axis indicates the cumulative number of occurrences of α# of the 5102-containing sealing epoxy resin, and the horizontal axis indicates the measurement time. sign (
b) Fi 5102 used in this example! t′1
The cumulative number of occurrences of U# in the sealing epoxy resin, the partner (B) indicated by the dashed line is the conventionally used silica-containing epoxy resin with the same blending ratio as the 8102-containing sealing epoxy resin used in this example. This is the cumulative number of a-line occurrences.

As can be seen from the figure, the cumulative number of alpha rays generated by the 5102-containing sealing epoxy resin used in this example was reduced to approximately 115, which is the cumulative number of alpha rays generated by the conventionally used silica-containing sealing epoxy resin. ing. Therefore, such ε1
In the resin-sealed semiconductor device of this example using commercial grade epoxy resin mixed with 0.02, α
The process of forming an organic film that attenuates the energy of the rays can be omitted or repeated. In particular, resin-sealed type L using this 5to2 mixed sealing epoxy resin.
In SI memory, it is possible to suppress the occurrence of soft errors due to alpha rays.

Nao, in this example, 70 weight percent 8102
510 made by mixing fine powder into epoxy resin as a filler
2 mixed sealing epoxy resin was used, but it is not necessarily '/
It is not necessary to limit it to 8102 fine powder with Og amount percent, and it may be 5102 fine powder with other weight percent, and it is not necessarily limited to epoxy resin, and 5to2 can be used with other resins such as silicone resin.
@It may be mixed with powder. Furthermore, in this example, 5iOI! in a gaseous state was used. 5102 generated from 4 has been described, but the present invention is not limited to this.
8 produced from other silicon compounds in a gaseous state
102 can also be applied.

As explained above, in the resin-sealed semiconductor device of the present invention, rCl is generated from a silicon compound in a gaseous state with a low content of radioactive isotopes that serve as an α-ray source.
Since we use a 5102-containing sealing resin in which 5to2 fine powder is mixed as a filler, the cumulative number of α-rays generated by this 5to2-containing sealing resin is equal to the α-rays of the conventionally used silica-containing sealing resin. This makes it possible to reduce the cumulative number of occurrences, and to omit or simplify the process of forming an organic coating on the surface of a semiconductor chip that attenuates the energy of alpha rays. In particular, in the resin-sealed L8 emitter using the 5102-containing sealing resin, the occurrence of soft errors due to alpha rays can be suppressed.

[Brief explanation of the drawing]

The figure is a diagram showing an example of the relationship between the cumulative number of alpha rays generated and the measurement time of the 5102-containing sealing epoxy resin used in one embodiment of the present invention. In the figure, the symbol (a) H is 81 used in the above embodiment.
02 α# Cumulative number of occurrences of mixed sealing epoxy resin, sign (
b) is the cumulative number of alpha rays generated by the conventionally used epoxy resin mixed with silica for sealing. Agent: Mr. Geino - (and others) Measuring feelings (min.) Procedural amendment (auto) May 11, 1972 To the Commissioner of the Japan Patent Office 1 - IG ('L) Indication Patent application 1982 -
No. 202305 No. 2, Title of the invention Resin-sealed conductor device 3, Relationship with 11 amendments Patent applicant Mi 5, Detailed description of the invention in the specification subject to amendment 6, Infield of amendment ( 1) U on page 1, line 17 to second negative line 5 of the specification
The reliability may be reduced. Due to the large size, internal stress is applied to the semiconductor chip and its constituent materials, reducing electrical characteristics and reliability, and in some cases, the sealing resin may break. Furthermore, since the thermal conductivity of the sealing resin is low, it is not easy to efficiently dissipate the heat generated during the operation of the semiconductor chip to the outside, and the semiconductor chip may be destroyed due to the temperature rise due to the generated heat. . ” he corrected. that's all

Claims (1)

[Claims] (1) A semiconductor chip is encapsulated using a resin mixed with silicon dioxide fine powder as a filler, which is produced from a silicon compound in a gaseous state with a low content of radioactive isotopes that serve as an alpha ray source. Resin-encapsulated semiconductor devices manufactured by