JPS58119657A - Resin sealed type semiconductor device - Google Patents

Abstract

PURPOSE:To obtain the highly reliable resin sealed type semiconductor device by a method wherein a sealing is performed using the epoxy resin composition having excellent dampproof property and high temperature electric characteristics. CONSTITUTION:The semiconductor device is sealed using the hardening material of the epoxy resin composition having, as essential components, novolak type epoxy resin of 170-300 epoxy equivalent (a), novolak type phenol resin (b) and organic phosphine borine or organic borine complex (c). The borine or organic borine complex, to be used as a hardening accelerator, is a blended compound of organic phosphine and borine or organic borine, and it is desirable that the above will be used within the range of 0.01-10wt% for resin component (epoxy resin and phenol resin).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly reliable resin-sealed semiconductor device sealed with a cured product of an epoxy resin composition.

Epoxy resin is widely used for encapsulating semiconductor devices as a highly reliable electrical insulating material with excellent electrical properties, mechanical properties, and chemical resistance.

Karichika uses epoxy resin compositions for low-pressure molding of most semiconductor devices, such as integrated circuits, large-scale integrated circuits, transistors, and diodes, instead of using conventional ceramics for single-metal sealing. It is sealed using.

As epoxy resin compositions for semiconductor encapsulation, epoxy resin compositions consisting of an epoxy resin, a novolac type phenol resin curing agent, and an imidasol curing accelerator are widely used in consideration of reliability, moldability, and the like.

However, resin-sealed semiconductor devices obtained by transfer molding conventional epoxy sealing resins have the following drawbacks.

(1) Moisture resistance is inferior to the high level of reliability required for resin-sealed semiconductor devices. (2) High temperature compared to the high level of reliability required for resin-sealed semiconductor devices. Regarding the moisture resistance mentioned above, resin-sealed semiconductor devices are sometimes used or stored in high-temperature atmospheres, so they must maintain reliability even under such conditions. As a rounding evaluation test for moisture resistance quality assurance, 8
An accelerated evaluation method of exposing 5υ stars to saturated water vapor at 120°C has been carried out, and recently a bias application type evaluation test has been conducted in which a voltage is applied to further increase acceleration.

However, the cured product of the sealed epoxy resin composition is hygroscopic and
Because it is moisture permeable, under such high-temperature conditions, moisture can penetrate from the outside through the cured sealing resin and into the inside.
! It enters the inside through the interface between the sealing resin and the lead frame, and reaches the IC on the surface of the semiconductor element. As a result of the action of this moisture and impurity ions existing in the sealing resin, resin-sealed semiconductor devices suffer from a decrease in insulation, an increase in leakage current, and waste corrosion of aluminum electrodes, wiring, etc. This causes damage to the upper body. When nine bias voltages are applied, the electrochemical action of the electrode (therefore, failures due to corrosion of the assimilium electrode and wiring occur frequently).

Conventional resin-sealed semiconductor devices are not fully satisfactory with respect to the above-mentioned moisture resistance, and there has been a demand for improved moisture resistance.

Next, to explain the electrical characteristics at high temperatures, resin-inserted semiconductor devices are sometimes used under high-temperature conditions, so reliability must be guaranteed even under such conditions. Generally, an accelerated test is performed in which reliability is evaluated by applying a bias voltage at 80'O to 150°C.

In such tests, the phenomenon of increased leakage current due to channeling is a common defect that occurs particularly frequently in devices with sensitive surface structures and devices with nine PN junctions to which a reverse bias is applied. Are known.

It is believed that the phenomenon of radiance occurs when an electric field acts on the resin layer that is in contact with the surface of the nine elements to which a voltage is applied.

Conventional resin-embedded semiconductor devices are not fully satisfactory with respect to the above-mentioned electrical characteristics at high temperatures, and improvements have been sought.

The purpose of the present invention is to solve the conventional resin-sealed semiconductor Af.
It is an object of the present invention to provide a highly reliable resin-sealed semiconductor device encapsulated with an epoxy resin composition that improves the drawbacks of t and exhibits excellent moisture resistance and high-temperature electrical characteristics.

In order to achieve the above object, the present inventors have conducted extensive research and have found that the curing accelerator is the main factor contributing to the above-mentioned difficulties.
It has been discovered that the resin for semiconductor encapsulation has superior moisture resistance and high-temperature electrical properties compared to conventional resins, and by using this resin, it has superior moisture resistance and high-temperature electrical properties compared to conventional resins. It has been found that nine resin-sealed semiconductor devices can be obtained.

That is, the present invention.

(a) Novolak epoxy tree with a working weight of 170 to 300] (b) Novolac type phenolic resin (C) Epoxy resin composition containing organic small sphine borine or organic borine complex as an essential component A resin-sealed semiconductor device is characterized in that the semiconductor device is sealed with a cured product of the resin-sealed semiconductor device.

The real deal! The epoxy resin used is a novolac type epoxy resin having an epoxy equivalent of 170 to 3000, examples of which include phenol novolak red epoxy resin, cresol novolac type epoxy resin, and halogenated phenol novolac type epoxy resin. These epoxy resins may be used alone or in a mixed system of two or more. Epoxy resins other than those listed above include general glycidyl ether type epoxy resins such as bisphenol A type epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, m-type aliphatic epoxy resins, alicyclic epoxy resins, and complex 1IlIIIl epoxy resins. The resin, halogenated epoxy resin, etc. has an epoxy equivalent of 170.
It can be used in combination with a novolak type epoxy resin of ~300. Formulation 1 is preferably 50% by weight or less based on the novolak type epoxy resin, and these epoxy resins have a chloride ion content of 10ppm or less and a hydrolyzable bulk content 1 of 0.1% by weight or less. desirable.

The novolac type phenolic resin curing agent used in the present invention includes phenol novolac resin, creso V
Examples include novolak resin, tert-butylphenol novolak resin, and nonylphenol novolak resin. These phenols/20 Le[111 softening point 60'O-? It is preferable that the curing agent is within the range of e-e'O, and furthermore, it is preferable that the phenol resin component soluble in water at room temperature is 3- or less. Can be used in a mixed system.

The blending ratio of the epoxy resin and curing agent is such that the ratio of the number of phenolic hydroxyl groups in the novolac type phenolic resin to the number of epoxy groups in the epoxy resin is within the range of 0.5 to 1.5. It is preferable to do so, and the reason is 0.5
This is because if it is less than 1.5 or more than 1.5, the reaction is insufficient to make paper making difficult and curing properties tend to deteriorate.

In the present invention, the borine of the organic phosphine used as a curing accelerator is the organoborine complex, which is a coordination compound of an organic phosphine and a borine or an organoborine, and is a coordination compound of the formula: where R1 is aralkyl 14, W gall, alkynyl .

i9 is an aryl group, and R2-R6 are hydrogen and alkyl.

Such compounds are alkenyl, alkynyl, aralkyl or aryl groups.

To give a concrete example, (C6H5)3P: BH3e (C6H1)3P
: B(CH3)3.

(C6H5)3P: B(C2Hs)s # (Cs
Hs) aP : BH(C4”9) 2 e(C6[(
5) 3P: B(C6Hs)s, (P-cHsC
sH4)sr: B(Q(a)s*(C4H,) 3
P 2B(13)s , (06F(,) 2)(
P: B(CH3) 3(G(s)2HP: B
H(CHs) 2 and the like. Among these, arylphosphine complexes are preferable, and these complexes have a ratio of 0.01 to 0.01 to
It is desirable to use within a range of 10-10% by weight.

The non-siliceous fillers used as necessary in this FIA include quartz glass powder, crystalline silica powder, glass fibers, talc, alumina powder, calumium silicate powder, calcium carbonate powder, barium sulfate powder, Magnesia powder, etc., but among these, quartz glass powder,
Crystalline silica powder is most preferred due to its high purity and low coefficient of thermal expansion.

However, the amount of these non-porous fillers varies depending on the type of epoxy resin, phenolic resin curing agent, and non-porous filler, but for example, when used in transfer molding, epoxy resin and phenolic resin curing Regarding the particle size distribution of the inorganic filler, which may be approximately 1.5 to 4 times the total amount of the filler (in terms of weight ratio), moldability can be improved by combining coarse particles and fine particles to make the distribution uniform. can do.

The epoxy composition according to the present invention may contain, for example, natural waxes, synthetic waxes, straight-chain fatty acid salts,
Chewing agents such as acid amides, esters or paraffins, flame retardants such as chlorinated paraffin, bromotoluene, hexabromobenzene, antimony trioxide, coloring agents such as carbon black, silane coupling agents, etc., as appropriate. There is no harm in adding a supplement.

The general method for preparing the epoxy resin composition of 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 treatment using K such as a kneader, an epoxy resin Flt type material can be easily obtained.

The resin-sealed semiconductor device of the present invention can be easily manufactured by sealing the semiconductor pupil using the above-mentioned epoxy resin composition or molding material.The most common method of sealing is There is a low-pressure transfer molding method, but injection molding is used.

Sealing by compression molding or casting is also possible. Special puncture methods include coating semiconductor surfaces with solvent-based or non-solvent-based compositions, and local sealing applications such as so-called junk coatings (which can also be used). can.

What about epoxy resin compositions or Iltl products during sealing?
The composition is cured by heating, and finally the composition is sealed with a cured molding material to obtain a resin-embedded semiconductor device. It is desirable to heat to 150'O or higher during curing.

Semiconductor devices included in the present invention include integrated circuits, large scale integrated circuits, transistors, thyristors, diodes, etc., but are not particularly limited.

A detailed description of the VC invention follows.

Actual examples 1 to 3 Cresol novolak type epoxy resin (contains epoxy resin) with epoxy equivalent weight of 220, brominated epoxy novolak resin with epoxy peak weight of 290 (epoxy resin B), molecule Wk
SOO's phenol crucible resin curing agent, (CaH
s)aP: BH3+ (CsHs)aP: B(
CWm)i #(C6H5)3P: B(C6H5)
s s 2-heptadecylindazole, dimethyl azomethylphenol, boron trifluoride triethylamine complex, quartz glass powder, antimony trioxide, carnauba wax, carbon black, silane coupling agent (r
-glycidoxypropyltrimethoxysilane) at the composition ratio (parts by weight) shown in Table 1, and by mixing each composition with a mixer and cross-mixing with a heated roll,
Six types of transfer molding materials were prepared including a comparative example.

By transfer molding using the molding material obtained in this way, the <8g integrated circuit is sealed with resin.
The mixture was molded at 5° C. for 5 minutes, and then aftertasted at 180° C. for 8 hours to make a paper.

The following tests were conducted on 100 of each of the above resin-sealed semiconductor devices.

(1) A moisture resistance test (bias PC'r) was conducted in water vapor at 120° C. and 2 atm to check for disconnection defects (due to corrosion) of aluminum wiring by applying IOV, and the results are shown in Table 2.

(2) Offset gate in oven at 100℃...SF
Drain voltage 5V, offset gate voltage 5V in r circuit
A test (MOS-BT test) is conducted to check for leakage current defects due to deterioration of electrical characteristics by applying a voltage of
The results are shown in Table 3 and circled.

The following are blank spaces: Table 1 Table 2 Table 3 As is clear from the above, a highly reliable resin phase IE type semiconductor device can be obtained by the present invention.

Claims (1)

[Scope of Claims] <t) (a) Novolac type phenolic resin 1bl novolac type phenolic resin with epoxy equivalent of 170 to 3000 and (C) Borin-1 of organic phosphine! 9. A resin-sealed semiconductor device characterized in that the semiconductor device is sealed with a cured product of an epoxy resin composition containing an organic borine complex as an essential component. (2) The resin-sealed semiconductor device according to claim 1, wherein the epoxy resin composition contains an inorganic filler.