JPS5967660A - Resin sealed type semiconductor device - Google Patents

Abstract

PURPOSE:To contrive to improve the moisture resistance and high temperature electrical characteristics by using epoxy resin, phenol aralkyl resin, and a sealer containing organic phosphine compound as the main material. CONSTITUTION:As the resin sealer for a semiconductor device, the epoxy resin, the phenol aralkyl resin, and the material containing organic phosphine compound are used. The epoxy resin is usually known and not particularly restricted. The phenol aralkyl resin is used as a hardener for the epoxy resin. The organic phosphine compound is used as a hardening promotor, and the moisture resistance or high temperature electrical characteristics can be improved by using it.

Description

[Detailed Description of the Invention] [Technical field to which the invention pertains] The present invention relates to a resin-encapsulated semiconductor device encapsulated with an epoxy resin composition, and more specifically, to a resin-encapsulated semiconductor device encapsulated with an epoxy resin composition, and more specifically, a resin-encapsulated semiconductor device encapsulated with an epoxy resin composition. The present invention relates to a resin-sealed semiconductor device.

[Technical disadvantage of invention jλ and its problems]

The resin-sealed semiconductor device is, for example, an integrated circuit (IC).

Large-scale integrated circuits (L, SI), transistors, diodes, and other semiconductor elements are sealed using thermosetting resin to protect them from the external atmosphere and mechanical shock.

Conventionally, hermetic sealing using metals, ceramics, etc. was used as a sealing technology for semiconductor devices.
Recently, resin encapsulation has become mainstream because it is economically advantageous.

Epoxy resin compositions for low-pressure molding, which can be used in low-pressure transfer molding methods suitable for OSE production, are generally widely used as such resins for early-obtained fiefdoms. However, for example, epoxy resin.

Conventional grease-sealed semi-Jt body devices obtained by transfer molding an epoxy resin composition comprising a novolak type phenolic resin curing agent, an imidazole curing accelerator, etc. have the following drawbacks. That is, (1) aluminum electrodes etc. are corroded and deteriorated due to poor 1lliJ humidity; (2) 1 lliJ characteristics are poor at MJ humidity, especially;
The functionality of the semiconductor device is degraded due to the increase in leakage current. Regarding (1) among these, resin-sealed semiconductor devices are sometimes used or stored in high-temperature, high-humidity atmospheres, so reliability must be guaranteed even under such conditions. As a reliability evaluation test for moisture resistance quality assurance, 85"C or 120°C
An accelerated evaluation method involving exposure to saturated water vapor has been conducted. Recently, bias application type evaluation tests have also been conducted in which a voltage is applied to further improve the acceleration performance.

However, in resin-encapsulated semiconductor devices using epoxy resin compositions, since the encapsulating resin has hygroscopic properties, moisture can escape from the external atmosphere through the encapsulating resin layer or through the interface between the encapsulating resin and the lead frame. It penetrates into the interior and reaches the surface of the semiconductor element.

As a result of the action of this moisture and impurities present in the sealing resin, resin-sealed semiconductor devices develop defects due to corrosion of aluminum electrodes, wiring, etc. Furthermore, when a bias voltage is applied, defects due to corrosion of aluminum electrodes and wiring occur particularly frequently due to its electrochemical action.

Next, regarding (2), since resin-sealed semiconductor devices are sometimes used under high-temperature conditions, reliability must be guaranteed even under such higher conditions. As a final evaluation test, an accelerated test is generally performed in which reliability is evaluated by applying a bias pressure at 80°C to 150°C.

In such tests, for example, an increase in leakage current due to channeling is detected as a defect that frequently occurs in MO8 elements whose semiconductor surfaces are sensitive to external charges, or elements with nine PN junctions when reverse bias is applied. There is a phenomenon that This phenomenon is thought to be caused by an electric field acting on the sealing resin layer that is in contact with the surface of the element to which voltage is applied.

In order to overcome the above-mentioned drawbacks of the conventional 1v1 fat-sealed semiconductor device, improvements have been sought.

[Purpose of issuing J]

The purpose of the present invention is to improve the drawbacks of the conventional 9411Ei sealed semiconductor device, and to provide a resin sealed semiconductor device with excellent moisture resistance and high temperature permeability. It's about doing.

[Summary of the invention]

In order to achieve the above object, the inventors of the present invention have conducted extensive research, and as a result, the following epoxy resin composition has superior properties as a semiconductor encapsulating resin compared to conventional epoxy resin compositions. By finding out that and using this, 1
It has been found that a resin-embedded semiconductor device with excellent moisture control properties and low temperature electrical properties can be obtained.

That is, the present invention provides 1. a semi-sealed semi-conductor formed by sealing a semiconductor device (i) with an epoxy resin (2) a conductor device in which the epoxy resin composition or (a) epoxy Resin (b) phenol aralkyl (ν1 fat and (c);
This is a resin-sealed semiconductor device 1.k characterized in that it contains a phosphine compound.

2. The present invention also provides a resin-sealed semiconductor device characterized in that the above-mentioned epoxy composition contains a novolac-type phenol fat.

The EBOKI/(νj resin used in the present invention is a commonly known one and is not particularly limited. νRIE is a bisphenol A-type EBOKI KIKEN JUKIBA, a phenol novolac-type epoxy JUTSUJI, a cresol novolak-ya epoxy resin, etc. Glycidyl ether type epoxy resin, glycidyl ester type epoxy resin.

Glycidylamine type epoxy 411J month, MA type 1
Examples include epoxy resins having two or more epoxy groups in one molecule, such as aliphatic epoxy resins, aliphatic epoxy resins, complex epoxy resins, and rogenated epoxy resins. However, these epoxy resins may be used alone or in a mixed system of two or more.

More preferable engineered 4-oxy resins used in the present invention have an epoxy equivalent of 170 to aoo (D/holock type epoxy resin, for example, phenol lenovolac type epoxy resin, cresol novolac type epoxy 11 i1'tt, halogenated These epoxy 4 fats are phenol novolac type epoxy 1 fats, etc. These epoxy 4 fats preferably have a chlorine ion content of 1Qppm or less and a hydrolyzable chlorine content of 0.1% by weight or less.The reason is Chlorine ion particles exceeding 10 ppm are 0.1
This is because if more than ii% of hydrolyzable chlorine is contained, the aluminum electrodes of the unsealed semiconductor element are likely to be corroded.

The phenol aralkyl resin used as a curing agent for epoxy resin in the present invention can be represented by the general formula [1].

However, n is an integer of 1 or more. The above-mentioned phenolic aralkyl resin can generally be obtained by condensing phenol and α,α-dimethoxyvaraxylene by a Friedel-Crach reaction. It is still commercially available under the trade name Zylock, so it is easily available.

In the above formula CI), a preferable value of n or a preferable average value of n is n = 2 to 20. Regarding the blending ratio of epoxy resin and phenol alkyl resin, it is desirable to mix the epoxy resin so that the number of phenolic hydroxyl groups in the phenol aralkyl resin is 0.5 to 1.5 per 1 epoxy group in the epoxy resin. . This is because outside the above range, characteristics are likely to deteriorate.

In the present invention, the novolak phenolic resin curing agent used together with the phenol aralkyl resin as a curing agent for epoxy resins includes phenol novolac resin, riL/sol novolak resin, tert-butylphenol novolak <nl lI fact, nonylphenol novolak resin, etc. Can be mentioned.

The softening point of these Novosic phenolic resins is 60'
It is preferably within the range of ~120°C, and even more so!
It is preferable that the water-soluble phenolic resin component in the crystal is 3% or less.

Regarding the blending ratio of novolak type phenolic resin, the fc! 11, phenol aralkyl resin and novolac ff! The total number of phenolic hydroxyl groups in phenolic resin is 0.5~
It is preferable to mix it so that it becomes 1.5. This is because outside the above range, characteristics are likely to deteriorate.

The blending ratio of phenol aralkyl 4ff, t II and novolak type phenol resin is such that novolak type phenol (work fat) is within the range of 0.01-100 parts by weight per 1 part by weight of phenol aralkyl resin. If it is less than 0.01, the effect of adding the novolac type phenol resin is recognized, and if it is 1fi (100 parts by weight or more, the effect of the phenol aralkyl resin is diminished.) In order to mix them together, a molten mixture of the two may be prepared in advance and used.

In the present invention, by using an organic phosphine compound as a curing accelerator, the moisture resistance and high-temperature electrical properties of resin-encapsulated semiconductor devices are significantly improved compared to when conventional curing accelerators such as imidazole and amines are used. It can be improved.

The organic phosphine compound used in the present invention has the formula [■]: t1 (also t-PCn) R.

2. A tertiary phosphine compound in which 几 is an organic group, a second phosphine compound in which only R3 is hydrogen, 几2. There are primary phosphine compounds in which R3 are both hydrogen. Specifically, triphenylphosphine, triphthylphosphine, tri/chlorohexylphosphine, methyldiphenylphosphine, butylphenylphosphine, and diphenylphosphine.

These include phenylphosphine and octylphosphine.

Group 1 may be an organic group containing an organic phosphine. Examples include 1,2-bis(diphenylphosphino)ethane and bis(diphenylphosphino)methane.

Among these, arylphosphines are preferred;
Triarylphosphines such as triphenylphosphine are preferably used as f. Yet these organic phosphine compounds are 1
It may be used in a mixed system of two or more buildings. However, the amount of the organic phosphine compound used in the lever is generally determined by the resin component (
(epoxy resin and curing agent) may be in the range of 0.001 to 20% by weight, but particularly preferable properties are obtained in the range of 0.01 to 5M%.

By specifically setting the blending amount of the organic phosphine compound within this range, resin-sealed semiconductor devices with excellent characteristics can be obtained.
I can do something like 'In'. When the compounding power 1 is less than 0.001% by weight, the effect of the addition is difficult to recognize, and there is a drawback that the curing of the epoxy resin composition takes a long time, and when it exceeds 20M%, the quality is adversely affected.

The epoxy resin composition according to the present invention may contain an inorganic filler if necessary, but in particular in the case of transfer molding of semiconductor elements such as integrated circuits and transistors, an inorganic filler may be added. It is preferable to mix it. The reason for this is, in part, to improve the characteristics.
Another reason is to minimize the difference in thermal expansion coefficient between parts to be sealed, such as elements, bonding wires, and lead frames. This is to reduce the number of defects that occur.

Inorganic fillers used in the present invention include quartz glass powder, crystalline glue powder, glass fiber, talc, alumina powder, silica powder, calcium carbonate powder, and barium sulfate powder.

Among these, quartz glass powder and crystalline silica powder are most preferred in terms of high purity and low coefficient of thermal expansion. However, the blending amounts of these inorganic fillers are 7 resins, 4 curing agents, and 4 inorganic fillers.
Although it varies depending on the class.

For example, when used in transfer molding, the weight ratio may be about 1.5 to 4 times the total amount of epoxy resin and curing agent. Regarding the particle size distribution of the inorganic filler, moldability can be improved by making the distribution uniform by combining coarse particles and fine particles.

The epoxy resin composition according to the present invention may contain, as necessary, natural waxes, synthetic waxes, Oya-type agents such as straight-chain fatty acid salts, acid amides, esters, or paraffins, chlorinated paraffins, bromine, etc. Flame retardants such as toluene, hexabromobenzene and antimony trioxide, coloring agents such as carbon black, and 7-run coupling agents may be appropriately added and blended.

A general method for preparing the epoxy resin composition according to the present invention as a molding material is to thoroughly mix the raw material components selected in a predetermined composition ratio, for example, with a mixer, and then further melt-mix with a hot roll, or By adding a mixing process using a kneader or the like, an epoxy resin molding material can be obtained more easily.

The resin-sealed semiconductor device of the present invention can be easily manufactured by sealing the semiconductor device using the epoxy resin composition or molding material. Low-pressure transfer molding is a common method for sealing, but injection molding is one of them.

Sealing by compression molding, casting, etc. is also possible. As a special sealing method, a method of coating a semiconductor surface using a solvent type or non-solvent type composition, and a method of local sealing as a so-called junction coating can also be used. It can also be used as a cutting composition for bonding.

The epoxy resin composition or molding material is cured by heating during sealing, and a resin-sealed semiconductor device can finally be obtained which is encapsulated with a cured product of the composition or molding material. During curing, it is desirable to heat the resin to 150° C. or higher.

The semiconductor device in the present invention includes an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, etc., and is not particularly limited.

〔Effect of the invention〕

As is clear from the above description of the purpose and summary of the present invention and the following examples, a resin-sealed half-2H1 device formed by sealing a semiconductor using the epoxy resin composition of the present invention is It has excellent moisture resistance as shown by the extremely low corrosion fault of aluminum wiring due to moisture at P(, 1T), and still has excellent moisture resistance as shown by the extremely low leakage current in the R40S-13T test.
．． It has excellent feel. Therefore, according to the present invention, a highly reliable resin-sealed semiconductor device can be obtained.

[Embodiments of the invention]

Next, synthesis examples of the present invention will be described.

Synthesis example 1 A phenolic aralkyl resin with a hydroxyl equivalent of 174.

Add 104 grams of phenolic novolac resin to the water.
o parts by weight were mixed and heated to 160'C to cause mutual dissolution to obtain a molten mixture. This was cooled and pulverized to obtain a raw material for epoxy resin composition 4.

Next, an embodiment of the present invention will be explained.

Examples 1 to 5 Cresol novolak type epoxy resin (epoxy resin A) with an epoxy equivalent weight of 220, brominated epoxy novolac resin with an epoxy equivalent weight of 1.1290 (epoxy resin ①3), phenol aralkyl resin with a hydroxyl equivalent weight of 1174, hydroxyl group A phenolic novolac resin having an equivalent weight of 104, the molten mixture of Synthesis Example 1, triphenylphosphine, 2-methylimidazole, dimethylaminomethylphenol, quartz glass powder, antimony trioxide, carnauba wax, carbon black, a 72-link coupling agent (γ-glycyl doxyglovir trimethoxy 7ran) with the composition shown in Table 1 (M.

Mix each composition using a mixer.

Ten cages of transfer molding materials, including a comparative example, were prepared by mixing wires using a heating roll.

The MO8 type integrated circuit was resin-sealed by transfer molding using the molding material thus obtained. For sealing, molding material i 1 was heated to 90°0 with a high-frequency preheater.
75'C! This was done by molding for 2 minutes at 200°C and after-curing for 8 hours at 200°C. The following test was carried out on 100 pieces of each of the above-mentioned IT4 fat-sealed semiconductor devices.

(1) IOV force 11 in water vapor at 120℃ and 2 atmospheres
(broken due to corrosion of aluminum wiring) ■Defective 81
A 4-beam moisture resistance test (bias PCT) was conducted and the results are shown in a-2.

(2) 100'Oノ, t-bu 7 middle thio 7 se! /
) 'y' - drain voltage 5 to MO8Fglr circuit
Test 11A (MO
A leak '1) L flow was determined to be defective if it increased to 100 times or more of the initial value, and the results are shown in Table 3.

Margin below Table-1 Table-2 Margin below Table-3 266-

Claims (1)

[Scope of Claims] (1) A resin-sealed semiconductor device formed by sealing a semiconductor device with an epoxy resin composition, wherein the epoxy resin composition is (a) epoxy HIy3 +J (b) phenol aralkyl resin and (C) a resin-encapsulated semiconductor group 1λ containing an organic phosphine compound. (2) Sealing the semiconductor device with an epoxy resin composition
When the resin-sealed semiconductor device is made of C, the epoxy resin composition contains (a) an epoxy resin, (b) a phenol aralkyl resin, (C) a novolac type phenol resin, and (d) an organic phosphine compound. A resin-sealed semiconductor device characterized by: (3) Epoxy resin is epoxy f7170-300
Claims t(
) The resin-sealed semiconductor device according to item 1 or 2. (4) In the epoxy resin composition, the blending ratio of the epoxy resin and the phenol aralkyl resin is such that the number of epoxy groups in the epoxy resin is 1 to the number of phenol alkyl (!i'0.5 of the phenolic hydroxyl groups of the phenolic fat). 1.5. (5) In the epoxy resin composition, the blending ratio of the epoxy resin, the phenol aralkyl resin, and the novolak type phenol resin is higher than that of the epoxy resin. The total number of phenolic hydroxyl groups in the phenol aralkyl resin and the novolac type Fer resin is 0.5 to 1.5 for the number of epoxy groups of 1.
A resin-sealed semiconductor device according to claim 2. (G) Resin sealing according to claim 2, wherein in the epoxy resin composition, the novolac type phenol resin is in the range of 0.01 to 100 parts by weight per 1 part by weight of the phenol alkyl resin. type semiconductor device 1δ. (7) In the epoxy resin composition, the resin-encapsulated semiconductor device (RA) according to claim 2, which uses a molten mixture of a phenol aralkyl resin and a novolak type phenol tJ resin. (8) Epoxy resin composition A resin-sealed semiconductor device according to claim 1 or 8112 of Patent I11, wherein the material further contains an inorganic filler.