JPH03174744A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve stress reduction with no pretreatment before packaging to electronic appliances and with resistance to heating in soldered packaging by sealing a semiconductor chip with an epoxy resin composite which contains two specific kinds of components. CONSTITUTION:A semiconductor chip is sealed with an epoxy resin composite which contains an epoxy resin represented by formula I and a reaction product obtained by preliminary reaction of a silane compound represented by formula II with a phenol aralkyl resin represented by formula III. In formula I R1-R4 are alkyl groups of carbon number 1-4; in formula II X is a monovalent organic group whose terminal has at least one functional group selected from a group consisting of glycidyl group, amino group, and mercapto group, Y is an alkoxy group of carbon number 1-4, and n is 0.1 or 2; and in formula III m is a positive integer. This constitution makes the device excellent in bonding strength of a semiconductor chip and sealing resin, prevents package cracks under severe conditions in soldering packaging to provide excellent moistureproof reliability, and improves stress reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor device that is excellent in both thermal shock resistance reliability and moisture resistance reliability.

[Conventional technology]

2. Description of the Related Art Semiconductor elements such as transistors, ICs, and LSIs are sealed in plastic packages and the like to form semiconductor devices from the viewpoint of protection from the external environment and from the viewpoint of enabling handling of the elements. A typical example of this type of package is the dual inline package (DIP).
There is. This DIP is of a pin insertion type, and a semiconductor device is attached by inserting pins into a mounting board.

Recently, the integration and speed of semiconductor devices such as LSI chips have been increasing, and in addition, the demand for smaller and more highly functional electronic devices has led to higher density packaging. From this point of view, surface mount packages have become mainstream instead of pin insertion type packages such as DIP. In a semiconductor device using this type of package, pins are taken out in a plane and fixed directly to the surface of the mounting board by soldering or the like. These surface-mounted semiconductor devices have pins that can be taken out on a flat surface, and have the advantages of being thin, light, and small.
Therefore, it has the advantage that it occupies only a small area on the mounting board, and also has the advantage that it can be mounted on both sides of the board.

On the other hand, the degree of integration of semiconductor devices is improving year by year, as typified by memory devices and microprocessors.
This has been achieved by miniaturizing the pattern of semiconductor elements and increasing the size of the elements. As a result, the contradictory problems of miniaturizing the package to be sealed and increasing the size of the element have arisen, and the sealing resin portion has inevitably become thinner.

[Problem to be solved by the invention]

However, in a semiconductor device using a surface mount package as described above, if the package itself absorbs moisture before surface mounting, there is a problem that cracks occur in the package due to the vapor pressure of moisture during solder mounting. That is, in a surface-mounted semiconductor device as shown in FIG. It accumulates on the back side. Then, when performing solder surface mounting such as vapor phase soldering,
The accumulated water is vaporized by the heating during the solder mounting, and its vapor pressure pushes the resin part on the back side of the die bond pad 4 downward, creating a gap 5 there. A crack 6 is generated in the package 3. In FIGS. 1 and 2, 8 is a bonding wire.

As a solution to these problems, there are methods in which the semiconductor element is sealed in a package, the resulting semiconductor device is then packaged in a moisture-proof package, and the package is opened and used immediately before surface mounting, or the semiconductor device is packaged immediately before surface mounting. A method of drying at 100°C for 24 hours and then performing solder mounting has been proposed and has already been implemented. However, such a pretreatment method has the problem that the manufacturing process is long and labor-intensive.

On the other hand, as semiconductor devices become larger, problems such as passivation cracks and aluminum sliding are occurring due to thermal stress. In order to solve these problems, a flexible substance such as rubber or silicone is usually dispersed in a resin composition, and the resin is sealed using this to reduce stress. However, if the above method is adopted, the water vapor diffusion coefficient of the resin composition increases, which is disadvantageous in terms of the occurrence of package cracks during solder mounting as described above.

The present invention was made in view of the above circumstances, and its purpose is to provide a semiconductor device that does not require pretreatment when mounted on electronic equipment and has excellent low stress properties that can withstand heating during solder mounting. shall be.

[Means to solve the problem]

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

(A) An epoxy resin represented by the following general formula (I).

(B) A reaction product obtained by preliminarily reacting a silane compound represented by the following general formula (II) and a phenol aralkyl resin represented by the following general formula (I[[).

(X+TVSi□(-Y) (n) [Function] As a method to prevent the occurrence of package cracks,
Three methods can be considered: suppressing moisture absorption into the sealing resin, ■ increasing the adhesive strength between the back side of the Guibond pad and the surface of the semiconductor element, and the sealing resin, and ■ increasing the strength of the sealing resin itself. . This invention is based on the method (2) above, to significantly reduce the water absorption rate of the sealing resin and suppress moisture absorption to the sealing resin, and based on the method (2) above, the surface of the semiconductor element and the sealing resin are This is intended to improve the moisture resistance of the package itself and the adhesive strength of the sealing resin by increasing the adhesive strength between the package itself and the sealing resin. Therefore, a reaction product of a special epoxy resin represented by the above general formula (1), a silane compound of the above general formula (II), and a phenol aralkyl resin of the above general formula (■) is used. As a result, it is possible to significantly improve the package crack resistance and moisture resistance reliability of the sealing resin at high temperatures (215 to 260° C.) such as in solder mounting. Furthermore, in advance, the above general formula (1)
By using a silicone compound reacted with one or both of the special epoxy resin and special reaction product represented by This invention was achieved by discovering that it is possible to achieve this.

The epoxy resin composition used in this invention has the general formula (
A special epoxy resin (component A) represented by 1), a silane compound of the general formula (If), and a silane compound of the general formula (II)
It is obtained by using the preliminary reaction product (component B) with the phenol aralkyl resin 1 of [), and is usually in the form of a powder or a tablet formed by compressing it.

The above-mentioned special epoxy resin (component A) is a biphenyl type epoxy resin and is represented by the following general formula (1).

In this way, by adding a lower alkyl group to a phenyl ring having a glycidyl group, it becomes water repellent. The epoxy resin component may be composed only of the above-mentioned special epoxy resin, or may be used in combination with other commonly used epoxy resins. In the former case, all of the A component is composed of the special epoxy resin of the above general formula (T), and in the latter case, a part of the A component is composed of the special epoxy resin of the above general formula (1). It will be configured. Examples of the commonly used epoxy resins 2 include various epoxy resins such as Talesol novolac type, phenol novolac type, novolak bis A type, and bisphenol A type. The above novolac type epoxy resin usually has an epoxy equivalent of 150 to 250.
．． 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 to 210°C and a softening point of 60 to 110°C are generally used. When both are used together in this way, it is preferable to set the epoxy resin represented by the above general formula (I) to 20% by weight or more (hereinafter abbreviated as "%") of the entire epoxy resin component, and particularly preferably. is 50% or more.

The above-mentioned special reaction product (component B) has the following general formula (I
A specific silane compound represented by I) and the following general formula (
It is obtained by preliminarily reacting with a specific phenol aralkyl resin represented by 1).

(X dimension n] Si-Y)3-11...(II)3 That is, the above special reaction product has the above general formula (II
) The organic group X and the alkoxy group Y of a specific silane compound represented by formula (III) are reacted with the OH group in a specific phenol aralkyl resin represented by general formula (III), and it is obtained by dealcoholization.

As the specific silane compound represented by the above general formula (I[), a silane coupling agent can be used, and specifically, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane, N -(2-aminoethyl)-
3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-a5nopropyltriethoxy4 silane, N,N-bis[(methyldimethoxysilyl)propyl]amine, N,N-bis[3- (methyldimethoxysilyl)propyl]ethylenediamine, N,N-bis(3-()rimethoxysilyl)propyl]amine, N,
N-bis(3-()rimethoxysilyl)propyl]ethylenecyagon, 3-(N,N-diglycidyl)alanopropyltrimethoxysilane, N-glycidyl-N,N-
Bis[3-(methyldimethoxysilyl)propyl]amine, N-glycidyl-N, N-bis[3-(trimethoxysilyl)propyl]amine, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidyl-N, Sidoxypropyltrimethoxysilane, 3mercaptotrimethoxysilane, 3-mercaptopropyltrimethoxysilane, N-(
Examples include (3-)rimethoxysilyl)propyl]diethylenetriamine, N-((3-trimethoxysilyl)propyl)triethylenetetraagon, N-3-1-rimethoxysilylpropyl-m-phenylenecyan, etc. It will be done.

5. The specific phenolic aralkyl resin represented by the above general formula (III) acts as a curing agent for the above-mentioned special epoxy resin, and can be obtained by reacting an aralkyl ether and phenol with a free sol fluorine catalyst. It will be done. Generally, condensation polymer compounds of α,α'-dimethoxy p-xylene and phenol monomers are known. As the above-mentioned phenol aralkyl resin, it is preferable to use one having a softening point of 70 to 110°C and a hydroxyl equivalent of 150 to 220. Further, the above-mentioned phenol aralkyl resin may constitute a curing agent component by itself, or may be used in combination with other commonly used phenol resins. In the former case, the entire curing agent component is composed of the above-mentioned phenol aralkyl resin, and in the latter case, a part of the curing agent component is composed of the above-mentioned phenol aralkyl resin. Examples of the above-mentioned commonly used phenolic resins include phenol novolac and talesol novolac. As these novolac resins, it is desirable to use those having a softening point of 50 to 110°C, a water 6 acid group equivalent of 70 to 150. When the above-mentioned phenol aralkyl resin and such a normal phenol resin are used together, it is preferable that the above-mentioned phenol aralkyl resin accounts for 50% or more of the entire curing agent component, particularly preferably 70% or more. be. The blending ratio of the phenol aralkyl resin (including ordinary phenol resin) is such that the hydroxyl group in the phenol aralkyl resin is 0.7 to 1°3 per equivalent of epoxy group in the special epoxy resin (component A). It is preferable to mix them in equivalent amounts.

More preferred is 0.9 to 1.1 equivalents.

The reaction product (component B) consisting of the specific silane compound and the specific phenol aralkyl resin can be obtained, for example, as follows. That is, the above-mentioned specific silane compound and specific phenol aralkyl resin are appropriately blended in a reaction vessel equipped with a stirring device, and the temperature is raised to 120 to 180"C, particularly preferably 130 to 150"C, and the two are reacted to form a reaction product. Next, the 7 alcohol produced in this reaction is removed from the yarn by degassing or the like under conditions of 130 to 180°C.

In addition, one or both of the special epoxy resin (A component) represented by the above general formula (I) and the reaction product (B component) react with the organopolysiloxane represented by the following general formula (IV). It is preferable to use one that has

By modifying with the organopolysiloxane in this manner, low stress properties are improved. In this case (2), the amount of the organopolysiloxane added is preferably set within the range of 1 to 7% of the total epoxy resin composition.

In addition, in addition to the special epoxy resin (component A) and the reaction product (component B), the epoxy resin composition used in this invention may optionally contain an inorganic filler, a curing accelerator,
Flame retardants, wax, etc. are used.

Examples of the above-mentioned inorganic fillers include crystalline and meltable fillers, as well as aluminum oxide, beryllium oxide, silicon carbide, silicon nitride, and the like.

The above-mentioned curing accelerators include amine type and phosphorus type.

Curing accelerators such as boron type and phosphorus-boron type are mentioned,
Used alone or in combination.

As the flame retardant, compounds such as novolac type brominated epoxy, bis A type epoxy, antimony trioxide, and antimony pentoxide may be used alone or in combination as appropriate.

As the above-mentioned coupling agent, methoxy or ethoxysilanes such as glycidyl-9-chill type, amine type, thiocyanate type and urea type are used alone or in combination as appropriate.

Methods of using it include triblending or preheating the filler, and premixing the ATC raw material, etc.
It is not particularly limited.

Examples of the wax include compounds such as higher fatty acids, higher fatty acid esters, and higher fatty acid calcium, which may be used alone or in combination.

The epoxy resin composition used in this invention includes:
In addition to the above additives, rubber components such as silicone oil, silicone rubber, and synthetic rubber are blended to reduce stress, and ion trapping agents such as hydrotalcite are added to improve reliability in moisture resistance tests. May be blended.

The epoxy resin composition used in this invention can be produced, for example, as follows.

That is, first, a reaction product (component B) is produced by preliminarily reacting the specific silane compound and the specific phenol aralkyl resin under the above conditions. Next, this reaction product (component B) and the above-mentioned special epoxy resin (component A) are suitably blended and premixed, and then melt-mixed by kneading in a kneading machine such as a mixing roll machine in a heated state. It can be produced through a series of steps of cooling to room temperature, pulverizing by known means, and, if necessary, tableting. In addition, when using the organopolysiloxane, the reaction product obtained above (component B) and the special epoxy resin (component A)
It can also be produced in the same manner as above after reacting with one or both of the above.

The encapsulation 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 a normal transfer bottom molding method.

The semiconductor device obtained in this way combines the special epoxy resin (component A) represented by the general formula (1) contained in the epoxy resin composition and the silane compound represented by the general formula (II) with the general formula ( Preliminary reaction product of III) with enol aralkyl resin (component B)
As a result, the encapsulating resin itself has reduced moisture absorption, and the adhesive strength between the semiconductor element and the encapsulating resin has also been improved, resulting in excellent thermal shock resistance and moisture resistant reliability.
Package cracks do not occur even during solder mounting.

〔Effect of the invention〕

As described above, the semiconductor device of the present invention uses an epoxy resin composition containing the above-mentioned special epoxy resin (component A) and a special preliminary reaction product (component B) to form a semiconductor element into a resin. Because it is sealed, it has excellent adhesive strength between the semiconductor element and the sealing resin, does not cause package cracks even under harsh conditions such as solder mounting, and has excellent moisture resistance and reliability. There is. Furthermore, by preliminarily reacting one or both of the special epoxy resin and the reaction product with the silicone compound, stress reduction is improved and excellent thermal shock resistance is provided.

Next, examples will be explained along with comparative examples. Ru.

First, prior to Examples, compounds shown in Table 1 below were prepared.

(Leaving space below) Next, the phenolic resins C, D and silane compounds E, F, and G in Table 1 above were added to a reaction vessel equipped with a stirring device at the mixing ratios shown in Table 2 below. A reaction product L-Q was prepared by preliminarily reacting under the reaction conditions shown and degassing (170°C).

(Left below) 5 6 Next, epoxy resins A and B shown in Table 1 above and organopolysiloxanes H and I shown in the same table were blended in the proportions shown in Table 3 below, and the mixture was stirred in a reaction vessel. Modified epoxy resins (a) to (f) were prepared by preliminary reaction. In addition, the reaction products M and O in Table 2 and the organopolysiloxane R in Table 1 are blended in the proportions shown in Table 4 below, and the modified reaction product (8) is prepared in the same manner as above. ~(i) was produced.

(The following are blank spaces) 7 8 29 [Examples 1 to 14, Comparative Examples 1 to 8] The above reaction products L-Q, epoxy resins A and B, modified epoxy resins (a) to (f), modified reaction products (g) ~ (i
) and other additives in the proportions shown in Table 5 below, and kneaded on a jixing roll machine at 100°C for 10 minutes to obtain a sheet-like composite. Then, the obtained sheet-like composite bottom was pulverized to obtain the desired powdered epoxy resin composition.

(The following is a blank space) 0 32 Next, a semiconductor device was obtained by molding a semiconductor element by transfer molding using the powdered epoxy resin 11 obtained in Examples 1 to 14 and Comparative Examples 1 to 8. . This semiconductor device is an 80-pin four-way flat package (QFP) (20 mm x 14 + nm x thickness 2.
5 mm), 7 mm x 7 punched Guipon plate,
It has a chip size of 6.5m++nx6.5mm. The semiconductor device thus obtained was immersed in solder at 260'C for 10 seconds, and the critical moisture absorption time at 85° C./85% RH until package cracking occurred was measured. Further, using the epoxy resin compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 4, a disk-shaped cured product with a thickness of 3 mm and a diameter of 50 mm was prepared (curing conditions: 180°C for 5 hours). This disc-shaped cured product was allowed to absorb moisture for 500 hours under 85'CX and 85% RH, and the saturated moisture absorption rate was measured. Furthermore, the bending strength of the cured product was measured at 260°C in accordance with JIS-69115,17. Next, Examples 1 to 14 and Comparative Examples 1 to 8
The adhesive force between the parabolic cured product of Epoxy Resin Set 3 obtained in and the semiconductor element was measured. These results are shown in Table 6 below. In addition, the said adhesive force was measured as follows. That is, FIG. 3(A)
And as shown in (B), a cured product 10 is prepared in which the upper surface has a diameter a = 11 mm, the lower surface has a diameter b = 9 mm, and a cone with a height h = 1.0 mm,
A semiconductor element 11 measuring 2 mm x 2 mm x 0.4 mm in thickness was mounted at the center of the upper surface of this conical cured product 10 . and,
The shear adhesive strength between this conical cured product 10 and the semiconductor element 11 was measured.

In addition, packages obtained in the same manner as above using the epoxy resin compositions obtained in Examples 8 to 14 and Comparative Examples 5 to 8 were allowed to absorb moisture for 72 hours at 85°C/85% RH. , solder immersion was performed at 260° C. for 10 seconds. This was left at 121° C. and 100% RH, and the moisture resistance deterioration time at which 50% failure occurred due to corrosion of the aluminum pattern portion on the surface of the semiconductor element was evaluated. Furthermore, the package obtained in the same manner was heated at 150°C to -60°C for 30 minutes.
A thermal cycle test was performed for 0 cycles, and the amount of deformation of the aluminum pattern wiring portion on the fourth side of the semiconductor element due to the thermal stress received from the sealing resin was measured.

(The following is a margin) 5 6 7 From the results in Table 6, the comparison height measurement has a low saturated moisture absorption rate and a long critical moisture absorption time, but has a low semiconductor element adhesive strength. In addition, comparative height measurement products other than Comparative Example 3 have a certain degree of adhesive strength, but have a high saturated water absorption rate and a short critical moisture absorption time. On the other hand, the specific product has a low saturated water absorption rate and a long limit moisture absorption time. Therefore, it can be seen that the practical products have excellent moisture resistance reliability and low stress properties at high temperatures. In addition, the products of Examples 8 to 16 have a long failure occurrence time and a small amount of deformation of the arc pattern wiring. From this, it can be seen that the above-mentioned product according to the embodiment is even more excellent in low stress properties. Moreover, it can be seen that all the products according to the implementation have high adhesive strength.

[Brief explanation of drawings]

FIGS. 1 and 2 are longitudinal cross-sectional views illustrating the occurrence of package cracks in conventional semiconductor devices, and FIG. Plan view explaining the adhesive force measurement method, 3rd
Figure (B) is its front view. 8 Figure (A), Ig Figure

Claims (5)

[Claims] (1) A semiconductor device in which a semiconductor element is sealed using an epoxy resin composition containing the following components (A) and (B). (A) An epoxy resin represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) [In the above formula (I), R_1 to R_4 have 1 carbon number
~4 alkyl group. ] (B) a silane compound represented by the following general formula (II);
A reaction product obtained by preliminary reaction with a phenol aralkyl resin represented by the following general formula (III). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) In the above formula (II), group, and Y has 1 carbon number
~4 alkoxy group. n is 0, 1 or 2. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) [In the above formula (III), m is 0 or a positive integer. ] (2) At least one of the epoxy resin of the component (A) and the reaction product of the component (B) has the following general formula (IV)
The semiconductor device according to claim 1, wherein the semiconductor device is reacted with an organopolysiloxane represented by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(IV) In formula (IV), R is a monovalent organic group, and they may be the same or different. However, in one molecule, at least two of the above R are an amino-substituted organic group, an epoxy-substituted organic group, a hydroxyl-substituted organic group, a vinyl-substituted organic group, a mercapto-substituted organic group, and a carboxyl-substituted organic group. A group selected from the group consisting of m
is an integer from 0 to 500. (3) The silane compound represented by general formula (II) is at least one selected from the group consisting of 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and 3-mercaptotrimethoxysilane. The semiconductor device according to claim 1 or 2, which is a silane compound. (4) An epoxy resin composition for semiconductor encapsulation containing the following components (A) and (B). (A) An epoxy resin represented by the following general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼…(I) [In the above formula (I), R_1 to R_4 have 1 carbon number
~4 alkyl group. ] (B) a silane compound represented by the following general formula (II);
A reaction product obtained by preliminary reaction with a phenol aralkyl resin represented by the following general formula (III). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(II) In the above formula (II), group, and Y has 1 carbon number
~4 alkoxy group. n is 0.1 or 2. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(III) [In the above formula (III), m is 0 or a positive integer. ] (5) At least one of the epoxy resin of component (A) and the reaction product of component (B) has the following general formula (IV)
The epoxy resin composition for semiconductor encapsulation according to claim 4, which is reacted with an organopolysiloxane represented by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(IV) [In formula (IV), R is a monovalent organic group and may be the same or different. However, in the molecule, at least two of the above R are amino group-substituted organic groups,
It is a group selected from the group consisting of an epoxy group-substituted organic group, a hydroxyl group-substituted organic group, a vinyl group-substituted organic group, a merpt group-substituted organic group, and a carboxyl group-substituted organic group. m is 0
~500 integer. ]