JPH08225632A - Sealing epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE: To obtain a sealing epoxy resin composition which can give a semiconductor device having a low moisture absorption and good crack resistance of solder resistant to moisture absorption and good reliability of humidity resistance by mixing a specified epoxy resin with a specified curing agent, specified inorganic fillers and a cure accelerator. CONSTITUTION: The sealing epoxy resin composition is obtained by mixing an epoxy resin containing 20-100wt.% epoxy resin having a dicyclopentadiene skeleton, represented by formula I (wherein n in 0 to 5), with an inorganic curing agent containing 20-100wt.% phenolic resin curing agent represented by formula II (wherein m is 0 to 5; and R is H or 1-5C alkyl), an inorganic filler containing 10-50wt.% inorganic filler of a particle diameter of 5μm or below and 20-100wt.% spherical inorganic filler, and a cure accelerator. This composition can give a semiconductor having a low moisture absorption and being excellent in crack resistance of solder resistant to moisture absorption and reliability of humidity resistance. By further adding an ion scavenger of formula III to the above composition, the obtained composition can give a semiconductor device having better reliability of humidity resistance.

Description

Detailed Description of the Invention

[0001]

The present invention relates to electric parts, electronic parts,
The present invention relates to a sealing epoxy resin composition for sealing a semiconductor element and the like and a semiconductor device using the composition.

[0002]

2. Description of the Related Art Conventionally, as a sealing method for electric / electronic parts such as diodes, transistors and integrated circuits, semiconductor devices, etc., for example, a resin sealing method using epoxy resin or silicon resin, glass, metal, ceramics, etc. The hermetic sealing method using has been adopted, but in recent years, in the sealing method using an epoxy resin, which has advantages in mass production and cost as well as improved reliability, cresol novolac type resin is used as the resin component. In addition, a molding material composed of a composition containing a phenol novolac type resin as a curing agent component is most commonly used.

However, as the density of electronic parts such as ICs, LSIs, VLSIs and semiconductor devices and the density of semiconductor devices have been increased, the molding resin has been made thinner, and the epoxy resin compositions used so far are not always satisfactory. Can no longer respond to. For example, in a surface mounting device, the device itself is suddenly exposed to a high temperature and harsh environment such as being directly immersed in solder at the time of mounting, so that the occurrence of package cracks is inevitable.
That is, moisture absorbed during storage after molding abruptly vaporizes and expands when exposed to high temperatures, and the sealing resin cannot withstand this and cracks occur in the package of the semiconductor device.

[0004] Regarding the encapsulating resin composition, improvement of heat resistance and adhesiveness has been studied. However, regarding these characteristics, especially reduction of hygroscopicity, resistance to moisture absorption solder cracking and moisture resistance reliability. Is not in a satisfactory situation yet.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor device having a low moisture absorption rate and good moisture absorption solder crack resistance and moisture resistance reliability. An object of the present invention is to provide an epoxy resin composition for encapsulation which is obtained, and a semiconductor device using the composition and having improved moisture absorption solder crack resistance and moisture resistance reliability.

[0006]

The epoxy resin composition according to claim 1 of the present invention is an epoxy resin composition for encapsulation, which is obtained by adding a curing agent, an inorganic filler and a curing accelerator to an epoxy resin. The epoxy resin having a dicyclopentadiene skeleton represented by the following general formula is contained in an amount of 20 to 100% by weight based on the total amount of the epoxy resin, and the phenolic resin curing agent represented by the following general formula is contained in the total amount of the curing agent. On the other hand, the content of the inorganic filler is 20 to 100% by weight, and the total amount of the inorganic filler is 10 to 10% of the inorganic filler having a particle diameter of 5 μm or less.
It is characterized by containing 50% by weight and 20-100% by weight of a spherical inorganic filler.

[0007]

[Chemical 4]

[0008]

Embedded image

The epoxy resin composition according to the second aspect of the present invention is characterized in that it also contains an ion scavenger represented by the following general formula.

[0010]

[Chemical 6]

A semiconductor device according to a third aspect of the present invention is obtained by encapsulating a semiconductor element using the encapsulating epoxy resin composition according to the first or second aspect.

The present invention will be described in detail below. The epoxy resin used in the present invention contains the epoxy resin represented by the general formula as an essential component. The repeating unit number n in the general formula is an integer of 0 to 5. The reason is that if the number of repeating units n exceeds 5, the viscosity becomes too high. Further, it is necessary to contain the epoxy resin having the dicyclopentadiene skeleton represented by the above general formula in an amount of 20 to 100% by weight based on the total amount of the epoxy resin. The reason for this is that when the epoxy resin having the dicyclopentadiene skeleton represented by the above general formula is less than 20% by weight with respect to the total amount of the epoxy resin, the moisture absorption rate is large, and the moisture absorption solder crack resistance and the moisture resistance reliability decrease. This is because

The epoxy resin other than the epoxy resin having the dicyclopentadiene skeleton represented by the above general formula, which can be used in the present invention, is 1
Any epoxy resin can be used as long as it is an epoxy resin having at least two epoxy groups in the molecule, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, triphenolmethane type epoxy resin. There are resins, biphenyl type epoxy resins, epoxy resins having a naphthalene ring, and brom-containing epoxy resins.

The curing agent used in the present invention contains a phenolic resin curing agent represented by the above general formula as an essential component. The number of repeating units m in the general formula is 0 to 5
Is an integer. The reason is that the repeating unit number m is 5
This is because if it exceeds, the viscosity becomes too high. Further, it is necessary to contain the phenolic resin curing agent represented by the above general formula in an amount of 20 to 100% by weight based on the total amount of the curing agent. The reason for this is that when the phenolic resin curing agent represented by the above general formula is less than 20% by weight with respect to the total amount of the curing agent, the moisture absorption rate is high and the moisture absorption solder crack resistance and moisture resistance reliability are low. This is because.

Hardeners other than the phenolic resin hardeners represented by the above general formula which can be used in the present invention include hardeners such as phenolic resins having at least two phenolic hydroxyl groups in one molecule. Any curing agent can be used, for example, phenol novolac resin, cresol novolac resin, and polyfunctional phenol resin.

As the inorganic filler, fused silica, crystalline silica, alumina, silicon nitride and the like can be used, and 10 to 50% by weight of the inorganic filler having a particle diameter of 5 μm or less is contained with respect to the total amount of the inorganic filler. , Spherical inorganic filler 20 to
It is necessary to contain 100% by weight. That is, particle size 5μ
When the content of the inorganic filler of m or less is less than 10% by weight based on the total amount of the inorganic filler, the moisture absorption solder crack resistance and the moisture resistance reliability decrease, and when it exceeds 50% by weight, The flowability deteriorates, the molded product becomes unfilled, and the content of the spherical inorganic filler is 2 with respect to the total amount of the inorganic filler.
If it is less than 0% by weight, the moisture absorption rate is high, and the moisture absorption resistance to solder cracking and the moisture resistance are lowered.

It is also preferable to contain an ion scavenger represented by the above general formula, and the inclusion of the ion scavenger in the encapsulating epoxy resin composition improves the moisture resistance reliability. The content of this ion scavenger is more preferably 10% by weight or less based on the total amount of the encapsulating epoxy resin composition. That is, when the content of the ion scavenger exceeds 10% by weight with respect to the total amount of the encapsulating epoxy resin composition, the fluidity during molding tends to deteriorate.

As curing accelerators, diazabicycloundecene, triphenylphosphine, tetraphenylphosphonium, tetraphenylborate, imidazole and 3
A primary amine or the like can be used. Further, if necessary, a coupling agent such as epoxysilane, a flame retardant such as brominated epoxy resin and antimony trioxide, a silicone flexibilizer, a release agent such as wax, and a pigment such as carbon black can be used. .

In this way, the above materials are blended, mixed,
The epoxy resin composition for encapsulation is obtained by kneading, pulverizing, and granulating if necessary. Further, using this epoxy resin composition for sealing, a semiconductor device is obtained by sealing a semiconductor element by compression molding, transfer molding, injection molding or the like.

With the above composition, it is possible to obtain a sealing epoxy resin composition having a low moisture absorption rate and improved moisture absorption solder crack resistance and moisture resistance reliability, and a semiconductor device using the composition.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples.

Regarding the compounding ingredients of Examples 1 to 9 and Comparative Examples 1 to 8, γ-glycidoxypropyltrimethoxysilane was used as a filler with respect to the total amount of the epoxy resin composition for sealing. 77.2% by weight of fused silica subjected to coupling treatment, 0.15% by weight of triphenylphosphine as a curing accelerator, and an epoxy equivalent of 4 as a flame retardant.
Brominated epoxy resin (1.4% by weight) and antimony trioxide (2.1% by weight), carnauba wax (0.3% by weight) as a release agent, and carbon black (0.1%) as a pigment.
The one containing 25% by weight was used.

As other compounding ingredients, the following substances were used in respective compounding amounts shown in Table 1 for Examples 1 to 9 and Table 2 for Comparative Examples 1 to 8. The numerical values shown in Table 1 and Table 2 show the content of each compounding component with respect to the total amount of the encapsulating epoxy resin composition in% by weight.

As the epoxy resin (E1), an epoxy resin having an epoxy equivalent of 257 and having a dicyclopentadiene skeleton represented by the above general formula (manufactured by Dainippon Ink and Chemicals, Inc .: trade name EXA7200) was used.

As the epoxy resin (E2), an ortho-cresol novolac type epoxy resin having an epoxy equivalent of 195 (manufactured by Sumitomo Chemical Co., Ltd .: trade name ESCN195X)
L) was used.

As the curing agent (H1), the hydroxyl equivalent is 157
The phenolic resin curing agent (trade name EXB6097, manufactured by Dainippon Ink and Chemicals, Inc.) in which R in the general formula is CH ₃ is used.

As the curing agent (H2), the hydroxyl equivalent is 104
Of phenol novolac resin curing agent (manufactured by Arakawa Chemical Industry Co., Ltd .: trade name Tamanol 754) was used.

In Example 9, the ion trapping agent represented by the above general formula (manufactured by Toagosei Kagaku Kogyo Co., Ltd .: trade name IEX600) was used as the ion trapping agent except for the ion trapping epoxy resin composition for encapsulation. 0.5 parts by weight was added to 100 parts by weight of the product.

The particle size is 5 with respect to the total amount of the inorganic filler.
The content of the inorganic filler of μm or less is referred to as R / M, and the content of the spherical inorganic filler is referred to as Q / M, which are shown in Table 1 and Table 2 in% by weight.

In each of the above-mentioned Examples and Comparative Examples, the above-mentioned components were uniformly mixed and dispersed by a mixer for 3 minutes,
The mixture was heated, melted and kneaded with a mixing roll having a roll temperature of 100 to 120 ° C. This kneaded product was cooled and pulverized to obtain each sealing epoxy resin composition.

Each of the epoxy resin compositions obtained above was molded by a transfer molding machine at a mold temperature of 175 ° C. and a molding pressure of 5
60 QFP after molding the semiconductor element with 0 kg / cm ²
TEG (outer shape: 15 mm × 19 mm × t2.4 mm)
I got Further, a disk for measuring a moisture absorption rate was obtained under the same molding conditions.

As a result of measuring the moisture absorption rate, the moisture absorption resistance solder crack and the moisture resistance reliability, as shown in Tables 1 and 2, Examples 1 to 9 are superior to Comparative Examples 1 to 8. Was confirmed

[0033]

[Table 1]

[0034]

[Table 2]

The measured values shown in Tables 1 and 2 are
By the following method. (1) Moisture absorption rate A disk having a diameter of 50 mm and a thickness of 3 mm manufactured according to JIS K 6911 was left in an atmosphere having a temperature of 85 ° C and a relative humidity of 85%, and the weight change after 72 hours was measured. (2) Moisture-absorption-resistant solder crack 60QFP TEG is left in an atmosphere at a temperature of 85 ° C. and a relative humidity of 85% for 72 hours to absorb moisture, and then soldered at 250 ° C. for 10
Immerse for 2 seconds, observe the presence of cracks with a stereoscopic microscope,
The number of packages in which cracks occurred in 10 0QFP was determined. (3) Moisture resistance reliability 60QFP TEG is left in an atmosphere at a temperature of 85 ° C. and a relative humidity of 85%, and after absorbing moisture for 72 hours, it is soldered at 250 ° C. for 10 hours.
Soak for 2 seconds, PCT (pressure cooker test) 1
After leaving in an atmosphere of 33 ° C. and 100% relative humidity, the presence or absence of open defects (circuit disconnection) in the aluminum circuit after 200 hours and 500 hours was observed, and the number of packages having open defects in 10 60QFP was determined. .

[0036]

According to the epoxy resin composition of the first aspect of the present invention, the epoxy resin having a dicyclopentadiene skeleton is contained in an amount of 20 to 100% by weight based on the total amount of the epoxy resin, and the phenol resin curing agent is used. 20 to 100% by weight of the total amount of the curing agent, and 10 to 5 of the inorganic filler having a particle diameter of 5 μm or less based on the total amount of the inorganic filler.
Since the content of 0% by weight and the content of the spherical inorganic filler of 20 to 100% by weight are included, a semiconductor device having a small moisture absorption rate, good moisture absorption solder crack resistance and moisture resistance reliability can be obtained.

According to the epoxy resin composition of claim 2 of the present invention, since it also contains an ion scavenger,
A semiconductor device having excellent moisture resistance reliability can be obtained.

The semiconductor device according to the third aspect of the present invention has good moisture absorption solder crack resistance and moisture resistance reliability and is useful.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 7/18 NLD C08K 7/18 NLD C08L 63/00 NKT C08L 63/00 NKT H01L 23/29 H01L 23/30 R 23/31

Claims (3)

[Claims] 1. An epoxy resin composition for encapsulation, which comprises a curing agent, an inorganic filler and a curing accelerator added to an epoxy resin, and an epoxy resin having a dicyclopentadiene skeleton represented by the following general formula 20 to 100% by weight based on the total amount of the resin, 20 to 100% by weight based on the total amount of the curing agent phenolic resin curing agent represented by the following general formula, and to the total amount of the inorganic filler On the other hand, an encapsulating epoxy resin composition containing 10 to 50% by weight of an inorganic filler having a particle diameter of 5 μm or less and 20 to 100% by weight of a spherical inorganic filler. Embedded image Embedded image 2. The epoxy resin composition for encapsulation according to claim 1, further comprising an ion scavenger represented by the following general formula. Embedded image 3. A semiconductor device obtained by encapsulating a semiconductor element using the epoxy resin composition for encapsulation according to claim 1 or 2.