JPS62224954A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a semiconductor device having excellent reliability through remarkable reduction or perfect elimination of hardening accelerator in the epoxy resin composition by sealing a semiconductor element with epoxy resin composition including epoxy resin, fenor resin and particular element. CONSTITUTION:A semiconductor device is sealed by an epoxy resin composition containing the epoxy resin, phenol resin and a reaction biproduct (C element) of polyalkylene glycol which is formed by the remaining group of heterocyclic compound in which the both ends of molecule chain have at least two class-2 amino group within the molecule and is coupled with nitrogen of any class-2 amino group of said remaining group at the end at the chain part of molecule chain and polydimethylsiloxane oligomer having at least one epoxy group at the end of molecule chain or side chain. Said C element shows the function of accelerating hardening in the hardening stage of resin. In the stage after hardening, it is firmly fixed to the epoxy resin of matrix. Accordingly, drop of electrical characteristic of epoxy resin hardened by transfer of hardening accelerator is no longer generated and a semiconductor device having high reliability may be attained.

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 have traditionally been sealed in ceramic packages and made into semiconductor devices, but recently, cost has increased.

From the viewpoint of mass production, resin sealing using plastic packages has become mainstream. Epoxy resins have conventionally been used for this type of resin sealing, and have achieved good results. However, due to technological innovation in the semiconductor field, the degree of integration has increased, element sizes have become larger, and wiring has become finer.As a result, packages are also becoming smaller and becoming WJ-shaped. There is a demand for improved reliability (internal stress, 1II4 humidity reliability, impact resistance, heat resistance reliability, etc. of the resulting semiconductor device). In particular, epoxy resin compositions used for semiconductor encapsulation mainly consist of an epoxy resin, a phenol resin as a curing agent, and a curing accelerator (mainly tertiary amines) that accelerates the reaction between the two. Curing accelerators, which are tertiary amines, exist freely in cured epoxy resins and are easily mobile at high temperatures, significantly reducing the electrical properties (especially electrical insulation) and moisture resistance of cured epoxy resins.
This deteriorates the electrical characteristics and moisture resistance reliability of the semiconductor device, and therefore improvements are desired.

[Problem that the invention seeks to solve]

2, conventional epoxy resin compositions for sealing use quite a large amount of curing accelerator, so they are not satisfactory in terms of electrical properties and moisture resistance, and it is difficult to use them. There is also a limit to the reliability of semiconductor devices, and further improvements in characteristics are strongly desired in order to cope with the increase in element size caused by the above-mentioned technological innovations.

This invention was made in view of the above circumstances, and it is possible to create a semiconductor device with excellent reliability by significantly reducing or eliminating the curing accelerator in the epoxy resin composition used for resin encapsulation. The purpose is to provide

[Means for solving problems]

In order to achieve the above object, the semiconductor device of the present invention includes:
Contains the following components (A) and (B), and further contains at least one component selected from the group consisting of the following components (C), (D), (B) and (F). It has a structure in which a semiconductor element is sealed using an epoxy resin composition.

(A) Evo 1 to Shiresin.

(B) Phenol resin.

(C) Both ends of the molecule t3'i are composed of residues of a heterocyclic compound having at least two secondary amino groups in the molecule, and the chain portion of the molecular chain is either one of the terminal residues. A reaction product of a polyalkylene glycol bonded to the nitrogen of a secondary amino group and a polydimethylsiloxane oligomer having at least one epoxy group at the end or side chain of the molecular chain.

(D) Both ends of the molecular chain are composed of residues of a heterocyclic compound having at least two secondary amino groups in the molecule, and the chain portion of the molecular chain is composed of residues of a heterocyclic compound having at least two secondary amino groups within the molecule, and the chain portion of the molecular chain is composed of residues of a heterocyclic compound having at least two secondary amino groups in the molecule, and A reaction product of a polyalkylene glycol bonded to the nitrogen of a secondary amino group and a polydimethylsiloxane oligomer having at least one carboxyl group at the end or side chain of the molecular chain.

(E) A polydimethylsiloxane oligomer having at least one epoxy group at the end or side chain of the molecular chain, a heterocyclic compound having at least two secondary amino groups in the molecule, and an epoxy group at both ends of the molecular chain. A reaction product with a polyalkylene glycol having a 1-cy group.

(F) A boridimethylsiloxane oligomer having at least one carboxyl group at the end of the molecular chain or a side chain, a heterocyclic compound having at least two secondary amino groups in the molecule, and at both ends of the molecular chain. Reaction product with polyalkylene glycol having epoxy groups.

In this invention, the term "reaction product" is used to include not only a product that has completely reacted but also a product that partially contains unreacted raw materials.

The epoxy resin composition used in this invention uses an epoxy resin (component A), a phenol resin (component B), and at least one component selected from the group consisting of component C, component D, component E, and component F. It is obtained using ingredients and is usually in powder form or tablet form.

The epoxy resin serving as the component A is not particularly limited, and various epoxy resins conventionally used as sealing resins for semiconductor devices can be mentioned, such as cresol novolac type, phenol novolac type, and bisphenol A type. Among these resins, it is preferable to use one that has a melting point above room temperature and is in the form of a solid or highly viscous solution at room temperature. Novolac type epoxy resin usually has an epoxy equivalent of 160 to 25.
0. Those with a softening point of 50 to 130°C are used, and the Talesol novolac type epoxy resin has an epoxy equivalent of 1
80-210. Those having a softening point of 60 to 110°C are generally used.

The phenolic resin of component B used together with the epoxy resin acts as a curing agent for the epoxy resin, and phenol novolak, talesol novolac, etc. are preferably used. These novolak resins are
It is preferable to use one having a softening point of 50 to 110°C and a hydroxyl equivalent of 70 to 150. Particularly, among the novolac resins mentioned above, use of Talesol novolac brings about good results.

The above C component has at least two ends of the molecular chain within the molecule.
A polyalkylene group consisting of a heterocyclic compound residue having 2 secondary amino groups, in which the chain part of the molecular chain is bonded to the nitrogen of any of the secondary amino groups of the 2 terminal groups. It is a reaction product consisting of equol and a polydimethylsilonide san oligomer having at least one epoxy group at the end or side chain of the molecular chain, and is obtained by stirring and mixing the two under heating.

The polyalkylene glycol having a heterocyclic compound at both ends, which is one of the components of component C, is schematically represented by the following formula (a) when the residues at both ends are, for example, piperazine residues.

This product is synthesized by stirring and mixing a polyalkylene glycol having epoxy groups at both ends of its molecular chain and a heterocyclic compound having at least two secondary amino groups within the molecule. Ru.

The polyalkylene glycol having an epoxy group used in the above synthesis is, for example, one represented by the following general formula (1), and commercially available products can be used. Among these, polypropylene in which R is a propylene group is preferably used. In the above general formula (1), when the number of repetitions n is less than 10, the heat resistance of the semiconductor device obtained using it decreases, and conversely, when it exceeds 200, the moisture resistance of the semiconductor device decreases. can be seen. Therefore, in formula (1) in -1-, it is preferable to use one in which the number of repetitions n is in the range of 10 to 200. Examples of the diheterocyclic compound include pyrazolidine, imidazolidine, piperazine, allantoin, benzimidazolone, and luminol.

On the other hand, polydimethylsiloxane oligomers having at least one epoxy group at the molecular chain end or side chain, which is another component of the above C component, are schematically shown below when the epoxy group is at the molecular chain end ( It is expressed as the formula (b), and when the epoxy group is in the side chain, it is expressed as the formula (c) below.

Polydimethyl IL > I+ $ 9 years old I mom- Therefore, the above-mentioned heterocyclic compound type polyalkylene glycol at both ends and borodimethylsilyl having an epoxy group:
The reaction product (component C) with the xane oligomer can be schematically represented by the following formula (d) or (e).

The number average molecular weight of such C component is preferably 20,000 or less, more preferably 15,000 or less, and most preferably 1.2,000 or less.

Here, the average molecular weight can be determined by quantifying the terminal secondary amino group per unit weight as follows. First, 5 g of a specimen is accurately weighed and dissolved in 30 g of isopropyl alcohol. Add 2-3 drops of bromophenol blue water/ethanol solution as an indicator and
．． Titrate with IN hydrochloric acid. The end point is the point where the system changes from blue-purple to yellow.

・In addition, component D used in this invention is composed of residues of a heterocyclic compound having at least two secondary amino groups at both ends of the molecular chain, and the restorative portion of the molecular chain is ``A polyalkylene glycol bonded to the nitrogen of any secondary amino group of the terminal residue described above and a polydimethylsiloxane oligomer having at least one carboxyl group at the molecular chain end or side chain are heated. This is a reaction product obtained by stirring and mixing the following.

The double-terminated heterocyclic compound type polyalkylene glycol, which is one of the components of the above component, is the same as that used as one of the components of component C.

On the other hand, polydimethylsiloxane oligomers having at least one carboxyl group at the end of the molecular chain or side chain, which is another component of the above-mentioned components, are schematically shown below ( It is represented as the formula 1.), and when the carboxyl group is in the side chain, it is represented as the following (I)2.

1100G ・
(g) Polydimethylsiloxane oligomer Therefore, the reaction product (component D) of the above-mentioned polyalkylene glycol with a heterocyclic compound at both ends and the polydimethylsiloxane oligomer having a carboxyl group is schematically shown below. It can be expressed as (su) expression or (nu) expression.

The average molecular weight of such a component is desirably 20,000 or less, more preferably 15,000 or less. , most preferably 12,000 or less.

Furthermore, the E component used in this invention is a polydimethyl silicone 1-sane oligomer having at least one epoxy group at the end or side chain of the molecular chain, and a heteropolymer silicone oligomer having at least two secondary amino groups in the molecule. It is a reaction product obtained by stirring and mixing a cyclic compound and a polyalkylene glycol having epoxy groups at both ends of the molecular chain under heating.

The polydimethylsiloxane oligomer having an epoxy group, which is one of the components of component E, is the same as that used as one of the components of component C.

On the other hand, the polyalkylene glycol containing a heterocyclic compound as another component of the IE acid component and an epoxy group as another component is It is the same as the raw material component of alkylene glycol.

Therefore, the reaction product (E
Component) generally consists of the same compound as the above-mentioned C component, and its structure is represented by the above-mentioned formulas (d) and (p).

In the above reaction, various reaction products are produced as by-products along with the C component compound, and unreacted raw materials also remain. Component E is thus a mixture of various compounds.

The number average molecular weight of such E component is preferably 20,000 or less, more preferably 15,000 or less,
Most preferably it is 12,000 or less.

In addition, the F component used in this invention is a polydimethylsiloxane oligomer having at least one carboxyl group at the end of the molecular chain or a side chain, and a heterocyclic compound having at least two secondary amino groups in the molecule. and a polyalkylene glycol having epoxy groups at both ends of the molecular chain, are mixed together under heating with stirring.

The polydimethylsiloxane oligomer having a carboxyl group, which is one of the constituent components of the above-mentioned component F, is the same as that used as one of the constituent components of the above-mentioned component.

On the other hand, the heterocyclic compound which is another constituent of the component F and the epoxy group which is another constituent of component The raw material components are the same as those for compound-type polyalkylene glycol.

Therefore, ``a polydimethylsiloquiline oligomer having two carpo-1-syl groups, a heterocyclic compound, and an epoxy! The reaction product (component F) with a polyalkylene glycol having (i) generally consists of the same compound as the above-mentioned component, and its structure is represented by the above-mentioned formula (S),
It will be represented by (nu). In the above reaction, various reaction products are produced as by-products along with the above component compounds, and unreacted raw materials also remain. Component F is thus a mixture of various compounds, similar to component E in Section 2.

The number average molecular weight of such F component is desirably 20,000 or less, more preferably 15,000 or less,
The most preferable value is 2000 or less.

The C component, D component, E component, and F component exhibit a curing accelerating effect during the curing stage of the resin due to the action of the heterocyclic compound residues at both ends of the molecular chain or the heterocyclic compound itself. In the post-curing stage, secondary amino groups, carboxyl groups, or epoxy groups in their molecular structures react with the epoxy groups of the 7-trix epoxy resin.
It is firmly fixed to the epoxy resin matrix. Therefore, it does not move even at high temperatures, does not cause deterioration in the electrical properties of the cured epoxy resin due to the movement of the curing accelerator as in the conventional case, and ensures reliability of the semiconductor device.

Each of the C component, D component, E component, and F component may be used alone, or two or more components may be used in an appropriate combination.

Containing at least one of the C component, D component, E component, and F component as described above (3) is an epoxy resin composition (A+B+ (C, D) excluding the filler component.

At least one of E and F) is desirably set to contain 5 to 40% (abbreviated as ``%''). In other words, if the content is outside the above range,
This is because the moisture resistance, electrical properties, etc. of the resulting semiconductor device tend to deteriorate. The epoxy resin composition used in this invention may contain the above (A) to
In addition to component (F), a curing accelerator is used, but the amount added is sufficient to be 0.5% or less based on the total amount of the phenol resin and epoxy resin. That is, the epoxy resin composition used in the present invention uses at least one of the C component, D component, E component, and F component, so that the amount of the curing accelerator used can be adjusted to be equal to that of the epoxy resin (component A) and the phenol. This can be suppressed within the range of 0 to 0.5% based on the total amount of resin (component B), thereby making it possible to significantly improve moisture resistance, electrical properties, etc.

Examples of the curing accelerator include the following tertiary amines.

Quaternary ammonium salts 5 Imidazoles and boron compounds can be mentioned as suitable examples, and these are ii
``L can be used alone or in combination.

Tertiary amine triethanolamine, tetramethylhexanediamine, triethylenediamine, dimethylaniline, dimethylaminoethanol, diethylaminoethanol, 2.4
．． 6-1-lis(dimethylaminomethyl)phenol,
N,N'-dimethylpiperazine, pyridine, picoline,
1.8-Diaza-bicyclo(5,4,0)undecene-
7, hensyldimethylamine, 2-(dimethylamino)
Methylphenol quaternary ammonium salt Dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyldimethyltel-ladecylammonium chloride, stearyltrimethylammonium chloride imidazoles 2-methylimidazole, 2-undecylimidazole, 2-ethylimidazole, 1. -benzyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole boron compound tetraphenylboron salts, such as triethyleneaminetetraphenylborate, N-methylmorbolinetetraphenylborate Also, if necessary, the above raw materials In addition, inorganic fillers, antimony dioxide, flame retardants such as phosphorus compounds, and coupling agents such as pigment 2 silane coupling agents can be used. The inorganic filler is not particularly limited, and may include commonly used quartz glass powder, talc, and silica powder.

Alumina powder or the like is appropriately used.

The epoxy resin composition used in this invention can be produced, for example, as follows. That is, first, the above-mentioned A component, B component, and at least one component appropriately selected from C-F components are mixed. At this time, other additives such as inorganic fillers, pigments, and coupling agents are appropriately blended and mixed as necessary. Next, the mixture thus obtained is put into a kneading machine such as a mixing roll machine, kneaded in a heated state, melt-mixed, cooled to room temperature, pulverized by known means, and tableted if necessary. The desired epoxy resin composition can be manufactured through a series of steps.

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

The semiconductor device obtained in this way has extremely poor electrical properties because the epoxy resin composition does not contain or contains only a very small amount of a curing accelerator that causes a significant decrease in its electrical properties and moisture resistance. Excellent and above C, D, E
, Due to the elasticity of the F component, it also has excellent low stress properties.

〔Effect of the invention〕

The semiconductor device of the present invention comprises four types of reaction products (C
- A special epoxy resin composition containing at least one component (F component) with no or significantly reduced curing accelerator is used to seal the plastic package. Because it is different from those made of epoxy resin compositions, it has poor moisture resistance, electrical properties, and heat resistance! ■It has high properties, low internal stress, and extremely high reliability. In particular, by using the special epoxy resin composition described above, high reliability as described above can be obtained in large semiconductor devices with 8 pins or more, especially 16 pins or more, or with a chip having a long side of 4 m1 or more. This is a major feature.

Next, examples will be described.

<Preparation of Component C> Component C was prepared as follows. That is, first, polyalkylene glycol-luminium, b, which has epoxy groups at both ends of the molecular chain shown in Table 1 below, and piperazine were mixed in the proportions shown in Table 2 below using 1,4-dioxane as a medium. , and reacted at 60°C for 8 hours. After the reaction was completed, the solvent 1°4-dioxane was removed under reduced pressure, and excess piperazine was removed by washing with water. and,
The reaction product was extracted with dichloromethane to obtain polyalkylene glycols (1) and (2) having heterocyclic compounds at both ends, which are one of the structural components of component C. The amino equivalent and structural formula of this product are also shown in Table 2.

(Left space below) Table 1 On the other hand, as a polydimethylsiloxane oligomer having an epoxy group, which is another component of component C, the following
The three types shown in the table (■, ■).

■) was prepared.

(Leaving space below) Then, by blending the polydimethylsiloxane oligomer having an epoxy group and the polyalkylene glycol with heterocyclic compounds at both ends in the proportions shown in Table 4 below, and stirring with heating, Four types of C to aim for
Ingredients (c, d, e.

f) was obtained.

4th person <Preparation of component D> Component D was prepared as follows. That is, first C
Polyalkylene glycols (1) and (2) having heterocyclic compounds at both ends used as components were obtained in the same manner.

On the other hand, as polydimethylsiloxane oligomers having carboxyl groups, which are other constituents of component D, there are three types shown in Table 5 below (■).

■, ■) were prepared.

(Left below) 2.Then, the above-mentioned polydimethylsylsilo; By doing so, the desired four types of D components (g, h.

i, j) were obtained.

Preparation of Component E> Component E was prepared as follows. That is, polyalkylene glycol-luminium, b, having epoxy groups at both ends of the molecular chain shown in Table 1 above, piperazine, and the third
The polydimethylsiloxane oligomers shown in the table without epoxy groups ○, ■, ■,
Three target E components (k, Cm) were obtained by blending in the proportions shown in Table 7 below and heating and stirring.

<Preparation of Component F> Component F was prepared as follows. That is, polyalkylene glycol-luminium, b, having epoxy groups at both ends of the molecular chain shown in Table 1 above, piperazine, and the fifth
Polydimethylsiloxane oligomers (1) and (2) having carboxyl groups shown in the table.

By blending and heating and stirring in the proportions shown in Table 8 below, three types of F components (n, o,
p) was obtained.

Table 8 (parts by weight) [Examples 1 to 19] The C-F component obtained as described above and other raw materials were blended in the composition shown in Table 9, and the mixture was heated on a mixing roll machine for 10 minutes at 100°C. The mixture was kneaded for a minute to obtain a sheet-like composition. Next, this sheet-like composition was pulverized to obtain the desired powdered epoxy resin composition.

As a reference example, a butadiene-acrylonitrile copolymer with carboxyl groups at both ends of the molecular chain, Hiker CT Polymer, CTBN 1, manufactured by Ube Industries, Ltd.
300X8, viscosity: 125000cps (27°C)2
Molecule Mini 3500. Acrylonitrile content: 17% by weight
, carboxyl group content: 2.37% by weight), and the raw materials shown in Table 9 were blended in the proportions shown in the same table to prepare a powdered epoxy resin composition. In addition, as a conventional example, using the raw materials shown in Table 9 below in the proportions shown in the same table,
A powdered epoxy resin composition was prepared.

(Left below) A semiconductor device was obtained by molding a semiconductor element by transfer molding using the powdered epoxy resin compositions obtained in the above examples, reference examples, and conventional examples.

The semiconductor device obtained in this way was subjected to internal stress 1 bending elastic modulus due to piezo resistance, 1000 hour reliability test using a pressure cooker under voltage application (hereinafter referred to as rPCBT test), -50°C for 15 minutes to 15 minutes.
Temperature cycle test of 2000 times for 15 minutes at 0°C (r
TCT test (abbreviated as “TCT test”) was conducted. The results are shown in Table 10 below. Note that the glass transition temperature (Tg
) indicates the temperature at which the peak of Tan δ of the viscoelastic property occurs.

(Leaving space below) From the results in Table 10, compared to the reference and conventional products, the plastic package of the implemented product has lower internal stress, has better electrical insulation, and has better moisture resistance and heat resistance. It can be seen that the

Claims (2)

[Claims] (1) Contains the following components (A) and (B), and further contains at least one component selected from the group consisting of the following components (C), (D), (E), and (F). A semiconductor device in which a semiconductor element is encapsulated using an epoxy resin composition. (A) Epoxy resin. (B) Phenol resin. (C) Both ends of the molecular chain are composed of residues of a heterocyclic compound having at least two secondary amino groups in the molecule, and the chain portion of the molecular chain is located at either end of the terminal residue. A reaction product of a polyalkylene glycol bonded to the nitrogen of a secondary amino group and a polydimethylsiloxane oligomer having at least one epoxy group at the end or side chain of the molecular chain. (D) both ends of the molecular chain are composed of heterocyclic compound residues having at least two secondary amino groups within the molecule;
A polyalkylene glycol in which the chain portion of the molecular chain is bonded to the nitrogen of any secondary amino group of the terminal residue, and a polyalkylene glycol having at least one carboxyl group at the end or side chain of the molecular chain. Reaction product with dimethylsiloxane oligomer. (E) A polydimethylsiloxane oligomer having at least one epoxy group at the end or side chain of the molecular chain, a heterocyclic compound having at least two secondary amino groups in the molecule, and an epoxy group at both ends of the molecular chain. Reaction products with polyalkylene glycols containing groups. (F) A polydimethylsiloxane oligomer having at least one carboxyl group at the end or side chain of the molecular chain, a heterocyclic compound having at least two secondary amino groups in the molecule, and an epoxy group at both ends of the molecular chain. Reaction products with polyalkylene glycols containing groups. (2) The semiconductor device according to claim 1, wherein the curing accelerator is contained in an amount of 0.5% by weight or less based on the total amount of components (A) and (B).