JPS61278155A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve the water resistance, by coating the semiconductor element with epoxy resin composition containing hydrotarxite group compound and then molding this element while covering it. CONSTITUTION:The main component of the epoxy resin composition to be used is epoxy resin and curative agent containing hydrotarxite. The semiconductor is coated with this epoxy resin composition and is molded. The hydrotarxite group compound acts not only to stabilize the plastic but also to take in sodium ion and chloride ion as a part of its crystal structure. Accordingly, sodium ion and chloride ion, etc. are adsorbed and eliminated so that the amount of ion to be activated is extremely decreased. Therefore, even when water penetrates into the plastic package made of the epoxy resin composition, the corrosion of the wiring of semiconductor element is prevented and its reliability is greatly increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a highly reliable semiconductor device.

[Conventional technology]

Semiconductor elements such as transistors, ICs, and LSIs are usually sealed with ceramic packages, plastic packages, or the like to form semiconductor devices. The above-mentioned ceramic package has heat resistance in the constituent material itself,
It also has excellent moisture permeability, so it is resistant to temperature and humidity.
Moreover, since it is a hollow package, it has high mechanical strength and can be sealed with high reliability. However, in recent years, resin sealing using the above-mentioned plastic package has become mainstream because the constituent materials are relatively expensive and the mass productivity is poor. Epoxy resin compositions have traditionally been used for this type of resin sealing, but as packages have become smaller and thinner in recent years, it has become easier for water to enter the resin. sodium in
Resin sealing using the epoxy resin composition is not satisfactory in terms of moisture resistance because it activates chlorine ions and corrodes the wiring of the device.

In particular, recent technological innovations in the semiconductor field have led to increased integration, larger element sizes, and finer interconnections.
Packages are also becoming smaller and thinner, and along with this, there is a demand for further improvements in moisture resistance (moisture resistance reliability of the resulting semiconductor devices, etc.) for sealing materials.

[Problem that the invention seeks to solve]

In order to improve the moisture resistance mentioned above,
The frame structure is undercoated with an organic compound such as silicone resin or polyimide resin to seal the resin, or to improve the interfacial adhesion between the lead frame material and puff cage resin to prevent water from entering from the interface. Although it has been proposed to improve the epoxy resin composition and to devise ways to mix the epoxy resin composition itself, the above-mentioned proposed methods are all sufficiently effective, but the above-mentioned problems still remain unsolved. That is the reality.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a semiconductor device having excellent moisture resistance and reliability.

[Means for solving problems]

In order to achieve the above object, the semiconductor device of the present invention includes:
The structure is such that a semiconductor element is covered and molded using an epoxy resin composition containing the following component (A).

(A) Hydrotalcite compound.

In order to meet the demand for improving the moisture resistance reliability of semiconductor devices, the inventors focused on reducing the amount of sodium ions and chloride ions in the epoxy resin composition, which cause a decrease in moisture resistance. As a result of repeated research, it was discovered that the intended purpose could be achieved by using a hydrotalcite a compound, and the present invention was achieved.

The epoxy resin composition used in this invention has an epoxy resin and a curing agent as main components, and contains the above-mentioned hydrotalcite compound, and is usually in the form of a powder or a tablet formed by compressing it. There is.

Hydrotalcite is a natural mineral that is produced in small amounts in the Ural region of the Soviet Union and Snarm in Norway.
It is expressed by the general formula bA lt (ON) 16CO3.4H20. Recently, this synthesis has been successful, e.g.
Gate ga, 5Alz(OH)tscO:+, 3.5H20
A hydrotalcite compound with the general formula is manufactured by Kyowa Chemical Industry Co., Ltd. as a plastic stabilizer (product name DIIT).
-4). Therefore, the hydrotalcite compounds in the present invention include not only the above-mentioned hydrotalcite, but also a wide range of compounds having properties similar to the hydrotalcite.

The inventors discovered that sodium ions in epoxy resin,
In the course of research on suppressing the activity of chloride ions, we confirmed that the above hydrotalcite compounds not only have a stabilizing effect on plastics, but also have the ability to incorporate sodium ions and chloride ions as part of their crystal structure.
When this is blended into the above epoxy resin composition, sodium ions, chloride ions, etc. will be adsorbed and removed, and even if water enters the plastic package made of the above epoxy resin composition, the amount of ions that will be activated will be reduced. They found that this drastically reduced the corrosion of the wiring in semiconductor devices, thereby significantly improving their reliability.

The epoxy resin used in this invention is not particularly limited, and examples include novolak and bisphenol thread-containing epoxy resins, but those with a softening point (according to the JIS falling ball method) of 60 to 85°C are particularly preferred. Typical examples of the novolac epoxy resins mentioned above include phenol novolac epoxy resins, cresol novolac epoxy resins, and halogenated phenol novolac epoxy resins. Typical examples of bisphenol epoxy resins include glycidyl ether type epoxy resins and glycidyl ester type epoxy resins. can be given. These resins may be used alone or in combination of two or more.

Examples of curing agents for epoxy resins used with the above epoxy resins include phenol resins (novolak epoxy resins only), acid anhydrides, polyamines, and the like. Among these, as the phenolic resin curing agent, phenol novolac resin, cresol novolac resin, tert-
Examples include butylphenol novolak resin, etc.; examples of acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, and hexahydrophthalic anhydride; examples of polyamines include metaphenylenediamine, paraphenylenediamine, Examples include 4"-diaminodiphenylmethane, 4.4°-diaminodiphenyl sulfone, etc. The above compounds may be used alone or in combination of two or more without any problem.

In addition to the above-mentioned essential components, a curing accelerator can be added to the epoxy resin composition of the present invention as an optional component, if necessary.

Examples of the curing accelerator include the following tertiary amines.

Suitable examples include quaternary ammonium salts, imidazoles and boron compounds.

Tertiary amine triethanolamine, tetramethylhexanediamine, triethylenediamine, dimethylaniline, dimethylaminoethanol, diethylaminoethanol, 2,4
．． 6-tris(dimethylaminoethyl)phenol, N
, N'-dimethylpiperazine, pyridine, picoline, 1
,8-diaza-bicyclo(5,4,O)undecene-7
, benzyldimethylamine, 2-(dimethylamino)methylphenol quaternary ammonium salt dodecyltrimethylammonium iodide, cetyltrimethylammonium chloride, benzyldimethyltetrabutylammonium chloride, stearyltrimethylammonium chloride.

Imidazoles 2-Methylimidazole, 2-undecylimidazole, 2-ethylimidazole, 1-benzyl-2-methylimidazole, ■-cyanoethyl-2-undecylimidazole Boron compounds tetraphenylboron, triphenylphosphine, tetraphenylborate N- Methylmorpholine tetraphenylborate In addition to the above ingredients, if necessary, inorganic fillers, mold release agents, antimony trioxide, flame retardants such as phosphorus compounds, pigments, coupling agents such as silane coupling agents, etc. , colorants, etc. can be used. The inorganic filler is not particularly limited, and may include commonly used calcium carbonate, calcium silicate, quartz glass powder, and talc.

Silica powder, alumina powder, etc. are used as appropriate. Further, as the mold release agent, higher aliphatic paraffins, higher aliphatic alcohols, higher aliphatic esters, higher aliphatic amides, higher aliphatic metal salts, natural waxes such as carnauba wax, synthetic waxes such as polyethylene wax, etc. and used as appropriate.

The epoxy resin composition used in this invention is produced by a conventionally known method using the above-mentioned raw materials, and is used as a plastic package for semiconductor devices. In other words, as mentioned above, the hydrotalcite compounds have the revolutionary property of adsorbing sodium ions, chloride ions, etc. in their own crystal structure, and are capable of absorbing the above ions in the resin. Because it adsorbs and drastically reduces the amount, corrosion of wiring, etc. caused by active sodium ions and chlorine ions does not occur even if water enters from the outside.This effect is due to the fact that hydrotalcite compounds The maximum amount is reached when the content is 0.05 to 10% by weight in the composition, based on the composition.

As mentioned above, the epoxy resin composition used in this invention can be produced by a conventionally known method.To explain this in more detail, it consists of an epoxy resin, a hydrotalcite compound, a curing agent, and optionally a curing agent. Accelerator, inorganic filler, mold release agent.

Add other additives such as pigments and coupling agents as appropriate,
This compound is kneaded in a heated state using a kneading machine such as a mixing roll machine to form a semi-cured resin composition, which is cooled to room temperature and then pulverized by known means and tableted as necessary. An epoxy resin composition can be obtained by this.

Sealing of a semiconductor element using such an epoxy resin composition is not particularly limited, and can be performed by a conventional method, for example, a known molding method such as transfer molding.

The semiconductor device thus obtained has excellent moisture resistance and reliability.

〔Effect of the invention〕

The semiconductor device of the present invention has extremely high moisture resistance reliability because it is sealed using an epoxy resin composition containing a hydrotalcite compound that adsorbs sodium ions and chloride ions. In particular, by sealing with the epoxy resin composition as described above, 8 bottles or more, especially 1 bottle.
This is a major feature, as it enables the above-mentioned high reliability to be obtained in large semiconductor devices with 6 or more pins or a chip with 4 or more long sides.

Next, examples will be described together with comparative examples.

[Examples 1 to 15. Comparative Examples 1 to 3] First, each raw material was blended with the composition shown in Table 1 below, and this blend was rolled for 3 to 5 minutes with a hot roll in a temperature range of 60 to 100°C.
After kneading for a minute, the mixture was cooled and pulverized to obtain a powder composition. Next, using the obtained powder composition, an aluminum corrosion element having aluminum wiring deposited on its surface was heated with a pressure cuff of 0 kg/ctA and a temperature of 175°C for 1 hour at 90°C.
Transfer molding was carried out under the conditions of 2 seconds to obtain a resin-sealed aluminum corrosion test element.

(Left below) [Test] Examples 1 to 15 and Comparative Example 1 thus obtained
For the resin-sealed aluminum corrosion test elements No. 3 to 3, a pressure tester test (rPcTJ hereinafter) was conducted at 121°C and 2 atmospheres, and a bias pressure tester was applied to further apply a voltage of 20 V at 121°C and 2 atmospheres. Tests (hereinafter abbreviated as "B-PCTj") were conducted on each to evaluate moisture resistance and corrosion resistance.The evaluation method was to determine open defects caused by corrosion of aluminum electrodes, and The number of defective products was used as a guideline for moisture resistance and corrosion resistance.

The results are shown in Table 2.

(Leaving space below) From the results in Table 2, it can be seen that all of the implemented height measurements have superior moisture resistance and corrosion resistance compared to the comparative height measurements, and in particular, the content of hydrotalcite m compound in the epoxy resin composition is 0 of things
．． 05-10%, better moisture resistance;
It can be seen that it has corrosion resistance.

Claims (2)

[Claims] (1) A semiconductor device formed by covering and molding a semiconductor element using an epoxy resin composition containing the following component (A). (A) Hydrotalcite compound. (2) The semiconductor device according to claim 1, wherein the hydrotalcite compound (A) is contained in the epoxy resin composition in an amount of 0.05 to 10% by weight.