JP2000119372A - Epoxy resin composition for sealing semiconductor and semiconductor device obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition for sealing a semiconductor, having a good molding property and working property, and also capable of obtaining a semiconductor device excellent in solder-resistance. SOLUTION: This epoxy resin composition for sealing a semiconductor contains specific components of (A) the following epoxy compound, (B) a phenol resin and (C) the following mixture of fused silica powder. (A) An epoxy compound obtained by performing an addition reaction of a mixed polyphenol obtained by mixing (a1) a biphenol expressed by the general formula (R1 to R4 are each hydrogen or a 1-5C alkyl group) and (a2) a biphenol (a polyphenol except for a1) in a weight mixing ratio (a1/a2) of (5/95)-(40/60) with an epihalohydrin. (C) A mixture of 3 kinds of fused silica powders having different mean particle diameters.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for semiconductor encapsulation having excellent solder resistance, moldability and workability, and a highly reliable semiconductor device obtained by using the same.

[0002]

2. Description of the Related Art Semiconductor devices such as transistors, ICs and LSIs are usually resin-sealed by transfer molding using an epoxy resin composition. Various types of packages have been developed as this type of package. As the epoxy resin composition used at the time of the above resin encapsulation, an epoxy resin composition mainly containing an epoxy resin and containing a phenol resin as a curing agent component and an inorganic filler is usually used. In particular, in recent years, biphenyl type epoxy resins have been widely used because of their excellent solder resistance.

[0003]

However, the encapsulating material using the above biphenyl type epoxy resin has the disadvantages that its curability is low, voids are generated in the obtained package, and the continuous moldability is poor. have.
On the other hand, as the epoxy resin, a polyfunctional epoxy resin represented by a cresol novolak type epoxy resin is often used, but the polyfunctional epoxy resin generally has a high resin viscosity and, for example, has good solder resistance. Therefore, there is a problem that the inorganic filler cannot be filled at a higher level, and sufficient solder resistance cannot be obtained. Therefore, in recent years, even with the above polyfunctional epoxy resin,
The type whose molecular weight is adjusted and made low in viscosity is available. However, although this epoxy resin has a low viscosity, it also has a problem in workability and the like because its softening point is lowered.

The present invention has been made in view of the above circumstances, and an epoxy resin composition for semiconductor encapsulation capable of obtaining a semiconductor device having good moldability and workability and excellent solder resistance. It is an object of the present invention to provide a product and a highly reliable semiconductor device using the same.

[0005]

In order to achieve the above object, the present invention provides, as a first gist, an epoxy resin composition for semiconductor encapsulation containing the following components (A) to (C).

(A) A biphenol (a1) represented by the following general formula (1) and a polyhydric phenol (a2) other than the biphenol (a1) are mixed in a weight ratio (a1 /
An epoxy compound obtained by subjecting a mixed polyhydric phenol obtained by mixing a1 / a2 in 5/95 to 40/60 in a2) to an addition reaction with epihalohydrin and a ring-closing reaction.

Embedded image

(B) a phenolic resin. (C) A mixture of three types of fused silica powder having the following average particle diameters (x), (y) and (z), wherein the fused silica powder having the above average particle diameter (x) is 50% of the total mixture. ~
92% by weight, 5 to 40% by weight of the fused silica powder having the above average particle size (y), the above average particle size (z)
Is from 3 to 15% by weight of the total mixture
Is set to (X) Average particle size of 20 to 60 μm. (Y) The average particle diameter of the fused silica powder selected and used from those having an average particle diameter of 20 to 60 μm as described in (x) above is α
, The average particle size represented by 0.1α ≦ average particle size (μm) ≦ 0.2α. (Z) The average particle diameter of the fused silica powder selected and used from those having an average particle diameter of 20 to 60 μm described in (x) above is α
Where 0.01α ≦ average particle size (μm) <0.1α
Average particle size represented by

Further, a semiconductor device in which a semiconductor element is encapsulated by using the above-mentioned epoxy resin composition for encapsulating a semiconductor is a second semiconductor device.
The summary of the

That is, the present inventors have conducted a series of studies to obtain an epoxy resin composition for semiconductor encapsulation which has excellent solder resistance, excellent fluidity and moldability. As a result, while using the special epoxy compound,
When a mixture of the fused silica powders obtained by mixing the three kinds of fused silica powders having the different average particle diameters at a specific ratio is used, for example, even if a large amount of the fused silica powder is used, a significant increase in viscosity is suppressed. It has been found that while maintaining a low viscosity of the entire system and obtaining good fluidity during molding, it becomes possible to obtain a sealing material having excellent reliability such as solder resistance and the like, and reached the present invention. .

When a phenol resin represented by the general formula (2) is used as the phenol resin, low hygroscopicity and low high-temperature flexural modulus can be obtained, and excellent solder resistance can be obtained. .

When butadiene rubber particles are used together with the above components as the epoxy resin composition for encapsulating a semiconductor, the epoxy resin composition is more excellent in low stress properties.

When the average roundness of the mixture of the fused silica powder is 0.7 or more, more excellent fluidity can be obtained.

[0013]

Next, an embodiment of the present invention will be described in detail.

The epoxy resin composition for semiconductor encapsulation of the present invention comprises a mixture (C) of a specific epoxy compound (component A), a phenol resin (component B), and three kinds of fused silica powders having different average particle sizes. Component) and is usually in the form of a powder or a tablet obtained by compressing the powder.

The specific epoxy compound (A) used in the present invention
Component) is a mixture obtained by mixing a biphenol (a1) represented by the following general formula (1) with a polyhydric phenol (a2) other than the biphenol (a1) at a specific weight mixing ratio. It is obtained by subjecting a polyhydric phenol to an addition reaction with epihalohydrin and a ring-closing reaction.

[0016]

Embedded image

Specific examples of the biphenols (a1) represented by the above formula (1) include 4,4'-dihydroxybiphenyl, 3,3 ', 5,5'-tetramethyl-4,
4'-dihydroxybiphenyl, 3,3 ', 5,5'-
Tetraethyl-4,4'-dihydroxybiphenyl,
3,3 ', 5,5'-tetrapropyl-4,4'-dihydroxybiphenyl and the like.

Examples of the polyhydric phenols (a2) other than the biphenols (a1) represented by the above formula (1) include phenol novolak, cresol novolak,
Examples include resorcinol novolak, bisphenol A type novolak, polyhydric phenols derived from p-hydroxybenzaldehyde, salicylaldehyde, and the like.
Among them, cresol novolak is preferably used from the viewpoints of moldability, moisture resistance reliability, and solder resistance.

The mixing ratio between the biphenol (a1) represented by the above formula (1) and the polyhydric phenol (a2) other than the biphenol (a1) is determined by the weight mixing ratio (a1 / a2). Is preferably set to a1 / a2 = 5/95 to 40/60, particularly preferably a1 / a2.
a2 = ratio of 10/90 to 30/70. That is, the biphenols (a
When the proportion of the polyhydric phenols (a2) other than 1) is increased, the resulting epoxy resin composition for semiconductor encapsulation has a high viscosity and is inferior in flowability. High solder resistance cannot be obtained. On the other hand, if the proportion of the polyhydric phenols (a2) is too small, curability is deteriorated, voids are generated, and continuous moldability is poor.

Then, a mixture obtained by mixing the biphenol (a1) represented by the above formula (1) and a polyhydric phenol (a2) other than the biphenol (a1) at the above specific weight mixing ratio. A specific epoxy compound can be obtained by adding an epihalohydrin to a polyhydric phenol and performing a ring-closing reaction. At that time, as the epihalohydrin, epichlorohydrin, epibromohydrin and the like are generally used.

The addition reaction and the ring-closure reaction between the above mixed polyhydric phenol and epihalohydrin are carried out in the usual manner as follows. That is, a predetermined amount of biphenols, polyhydric phenols, epihalohydrin and isopropyl alcohol are added and dissolved in a reaction vessel equipped with a stirrer, a thermometer and a condenser, and then the solution is heated to 35 ° C. A predetermined amount of an aqueous sodium hydroxide solution is added dropwise over 1 hour. During this period, the temperature was gradually raised to 65 ° C. at the end of the dropping of the aqueous sodium hydroxide solution, and then maintained at 65 ° C. for 30 minutes to complete the reaction. After removal of the sodium, excess epihalohydrin and isopropyl alcohol are evaporated off under reduced pressure to give the crude epoxy compound. Next, the crude epoxy compound is dissolved in toluene, an aqueous solution of sodium hydroxide is added, and the mixture is kept at 65 ° C. for 1 hour to cause a ring closure reaction. After the completion of the ring closure reaction, sodium phosphate monobasic was added to neutralize excess sodium hydroxide, washed with water to remove by-product salts, and then the solvent was completely removed under reduced pressure to remove the desired epoxy. A compound is obtained.

In the present invention, as the epoxy resin component, other epoxy resins may be used in addition to the specific epoxy compound (component A). Other epoxy resins are not particularly limited, and include conventionally known epoxy resins, for example, various epoxy resins such as cresol novolak type, phenol novolak type, bisphenol A type, and naphthalene type, and brominated epoxy resins. These can be used alone or in combination of two or more. When the other epoxy resin is used in combination, the combination ratio may be set to such an extent that the effect of the present invention is not impaired. For example, the other epoxy resin may be set to 50% by weight or less of the entire epoxy resin component. Is preferred.

The phenolic resin (component (B)) used together with the specific epoxy compound (component (A)) acts as a curing agent and is not particularly limited, and various conventionally known phenolic resins are used. For example, phenol novolak resin, cresol novolak resin,
Bisphenol A type novolak resin, phenol aralkyl resin and the like can be mentioned. These phenol resins are used alone or in combination of two or more. In particular, a phenol resin represented by the following general formula (2) is preferably used in that good solder resistance due to low moisture absorption and low-temperature elastic modulus can be obtained.

[0024]

Embedded image

The mixing ratio of the specific epoxy compound (component A) and the phenol resin (component B) is such that the hydroxyl group equivalent in the phenol resin component is 0.5 to 2.0 equivalent per equivalent of epoxy group in the epoxy compound. It is preferable to mix them so that It is more preferably 0.8 to 1.2 equivalents.

The mixture (component C) of the fused silica powder used together with the above components A and B is a mixture of three types of fused silica powder having the following average particle diameters (x) to (z). The average particle diameter is measured by a laser diffraction scattering type particle size distribution measuring device. (X) Average particle size of 20 to 60 μm. (Y) The average particle diameter of the fused silica powder selected and used from those having an average particle diameter of 20 to 60 μm as described in (x) above is α
, The average particle size represented by 0.1α ≦ average particle size (μm) ≦ 0.2α. (Z) The average particle diameter of the fused silica powder selected and used from those having an average particle diameter of 20 to 60 μm described in (x) above is α
Where 0.01α ≦ average particle size (μm) <0.1α
Average particle size represented by

That is, these three types of average particle diameters:
It is necessary to mix the fused silica powder (x) having a large average particle diameter, the fused silica powder (y) having a medium particle diameter, and the fused silica powder (z) having a small particle diameter in the following proportions. is there. By mixing so as to have such a ratio, even if the silica powder which is an inorganic filler is highly filled, good fluidity is obtained with little decrease in fluidity, and low moisture absorption due to high filler filling. This is because strength is improved and good solder resistance is obtained.

Fused silica powder having an average particle size of 20 to 60 μm (x) accounts for 50 to 92% by weight of the whole mixture. The fused silica powder having an average particle size (y) represented by 0.1α ≦ average particle size (μm) ≦ 0.2α is 5 to 40% of the whole mixture.
weight%. The fused silica powder having an average particle diameter (z) represented by 0.01α ≦ average particle diameter (μm) <0.1α is 3 to 1 of the entire mixture.
5% by weight. [However, α is the average particle size of 20 to 60 in the above (x).
It is the average particle size of the fused silica powder selected and used from those of μm. ]

The average roundness of the mixture (component C) of the above three kinds of fused silica powders having different average particle diameters is preferably 0.7 or more. Particularly preferably, 80% by weight or more of the whole mixture has a roundness of 0.8 or more. That is, when the whole mixture has a roundness of 0.7 or more, the fluidity can be further improved.

The roundness is calculated as follows. That is, as shown in FIG. 1A, when the actual area of a projected image 1 of an object whose roundness is to be measured is α and the length of the periphery of the projected image 1 is PM, As shown in FIG. 1 (b), it is assumed that a projection image 2 is a perfect circle having the same circumference as the projection image 1 described above. Then, the area α ′ of the projection image 2 is calculated. As a result, the ratio of the actual area α of the projection image 1 to the area α ′ of the projection image 2 (α /
α ′) indicates the roundness, and this value (α / α ′) is calculated by the following equation (A). Therefore, the roundness is 1.
As is clear from this definition, 0 can be said to be a perfect circle. Then, the more irregularities are on the outer periphery of the object, the smaller the roundness becomes sequentially smaller than 1.0. In the present invention, the roundness of the fused silica powder mixture is a value obtained by extracting a part from the mixture (population) to be measured and measuring the same by the above method, and usually the average roundness. It refers to circularity.

[0031]

(Equation 1)

The total amount of the mixture (component (C)) of the three types of fused silica powders having different average particle diameters is preferably at least 75% by weight, particularly preferably 80 to 80% by weight of the entire epoxy resin composition. 90% by weight. That is, if the content is too small, such as less than 75% by weight, the solder resistance tends to be poor.

In the present invention, in addition to the components A to C, butadiene rubber particles can be used for the purpose of improving the stress reduction. As the above-mentioned butadiene rubber particles, those obtained by a copolymerization reaction of alkyl methacrylate, alkyl acrylate, butadiene, styrene and the like are usually used. Specific examples include a methyl methacrylate-butadiene-styrene copolymer and a methyl methacrylate-ethyl acrylate-butadiene-styrene copolymer. Among the above copolymers, a methyl methacrylate-butadiene-styrene copolymer having a butadiene composition ratio of 70% by weight or less and a methyl methacrylate composition ratio of 15% by weight or more is suitably used. And
As the butadiene-based rubber particles, those having an average primary particle size of 0.05 to 40 μm are preferably used, and particularly preferably 0.05 to 10 μm. Also,
The butadiene-based rubber particles preferably have an average particle diameter of secondary particles of 100 μm or less, and particularly preferably have an average particle diameter of secondary particles of 20 to 50 μm.
That is, when the average particle diameter of the secondary particles is less than 20 μm, the handling as a powder tends to be remarkably deteriorated. On the contrary, when the average particle diameter exceeds 100 μm, poor dispersion occurs. Further, the butadiene rubber particles used in the present invention may have a specific average particle size in the secondary particles and 80% of the secondary particles.
It is preferable that the particle size is 150 μm or less. Particularly preferably, the particle size is 150 μm or less, which is 100%. That is, when the particle diameter of the secondary particles is 150 μm or less and less than 80%, for example, a sufficient dispersion state cannot be obtained when the particles are melted and mixed by a kneader. And it is preferable that the maximum particle diameter of the secondary particles is 250 μm or less, together with the specification of the particle diameter.

The compounding amount of the butadiene rubber particles is preferably set to a ratio of 0.1 to 4.0% by weight of the whole epoxy resin composition, more preferably 0.1 to 2% by weight. That is, if the content is less than 0.1% by weight, a sufficient effect of lowering the stress of the epoxy resin composition cannot be obtained. If the content exceeds 4.0% by weight, the reliability of the semiconductor element due to ionic impurities contained in the rubber particles is reduced. This is because there is a tendency that the rubber particles are not sufficiently and uniformly dispersed.

Further, in addition to the above components, a silicone compound may be used. As described above, the use of the above-mentioned silicone compound makes it possible to obtain more excellent moisture resistance reliability. This is because the silicone compound acts as a surface treatment agent, and the adhesiveness between the cured epoxy resin composition and the semiconductor element is further improved, and moisture resistance is improved due to water repellency. It is considered to be. As the silicone compound, at least 2
Those having two functional groups are preferable, and examples thereof include a silicone compound represented by the following general formula (3). These are used alone or in combination.

[0036]

Embedded image

The epoxy resin composition for encapsulating a semiconductor of the present invention may further comprise, if necessary, a curing accelerator, a halogen-based flame retardant, antimony trioxide, etc., in addition to the components A to C, various rubber particles, and a silicone compound. Other additives such as a flame-retardant auxiliary such as a carbon black, a pigment such as carbon black, and a silane coupling agent such as γ-glycidoxypropyltrimethoxysilane are appropriately used.

Examples of the curing accelerator include amine type and phosphorus type. Examples of the amine type include imidazoles such as 2-imidazole, triethanolamine,
1,8-diazabicyclo (5,4,0) undecene-7
And the like tertiary amines. Examples of the phosphorus type include triphenylphosphine and the like. These are used alone or in combination. And the compounding ratio of this curing accelerator is 0.1 to 0.1% of the entire epoxy resin composition.
It is preferable to set the ratio to 2.0% by weight. Further, considering the fluidity of the epoxy resin composition, it is preferably 0.15 to 0.35% by weight.

The epoxy resin composition for semiconductor encapsulation of the present invention can be produced, for example, as follows. That is, after mixing and mixing the components A to C, the inorganic filler and the butadiene-based rubber particles and the silicone compound, and other additives as necessary, the mixture is melted and mixed in a kneading machine such as a mixing roll machine in a heated state. After cooling to room temperature, it can be manufactured by a series of steps of pulverizing by known means and tableting as required. When the butadiene-based rubber particles are blended in blending the above components, at least one of the components A and B and the butadiene-based rubber particles may be preliminarily mixed, and then the remaining components may be blended.

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 ordinary transfer molding.

Next, examples will be described together with comparative examples.

Each component shown below was prepared.

[Epoxy a] YL-6640, manufactured by Yuka Shell Epoxy

[Epoxy b] Biphenyl type epoxy resin represented by the following formula (4) (epoxy equivalent 192, melting point 107 ° C.)

[0045]

Embedded image

[Epoxy c] o-cresol novolak type epoxy resin (epoxy equivalent 195, softening point 80 ° C.)

[Epoxy d] novolak type brominated epoxy resin (epoxy equivalent 275, softening point 84 ° C.)

[Phenol resin a] Phenol novolak resin (hydroxyl equivalent 105, softening point 83 ° C.)

[Phenol resin b] XLC-225, manufactured by Mitsui Chemicals, Inc. (hydroxyl equivalent 170, softening point 83 ° C.)

[Inorganic fillers ad] Various silica powders shown in Table 1 below were prepared.

[0051]

[Table 1]

[Coupling agent] γ-glycidoxypropyltrimethoxysilane

[DBU] 1,8-diazabicyclo (5,
4,0) undecene-7

[Carnauba wax]

[Butadiene rubber] Methyl methacrylate-butadiene-styrene copolymer rubber particles having an average primary particle diameter of 0.2 μm

[0056]

Examples 1 to 6 and Comparative Examples 1 to 6 Tables 2 and 3 below
Are blended in the proportions shown in the same table, and 80 to 12
The mixture was melt-kneaded in a roll kneader (5 minutes) heated to 0 ° C. Next, the melt was cooled, pulverized, and further tableted to obtain an epoxy resin composition for semiconductor encapsulation.

[0057]

[Table 2]

[0058]

[Table 3]

Using the epoxy resin compositions of Examples and Comparative Examples thus obtained, the spiral flow value, gel time and flow tester viscosity were measured according to the following methods. The results are shown in Tables 4 and 5 below.

[Spiral flow value] Each of the above epoxy resin compositions was used in the form of a powder, and was previously heated to a specified temperature (1
(75 ± 5 ° C), insert the spiral spiral mold to the back of the pot, and close the mold to reduce the mold clamping pressure to 2
Increased to 10 ± 10 kg / cm ² . Next, when the mold clamping pressure reached 210 ± 10 kg / cm ² , the epoxy resin composition was injected with a plunger, and the injection pressure was set to 70 ± 10 kg / cm ^2.
After reaching 5 kg / cm ² , injection pressure was applied for 2 minutes. Next, the plunger pressure of the transfer molding machine was released, and the mold clamping pressure was released to open the mold. Then, the spiral flow value was obtained by measuring the spiral length of the molded product to a minimum of 2.5 mm (EMMI 1-
66).

[Gel Time] A sample (200 to 500 mg) was placed on a hot plate at a prescribed temperature (175 ° C.), stretched thinly on the hot plate with stirring, and from when the sample was melted on the hot plate until it hardened. The time was read as the gel time.

[Viscosity of Flow Tester] 2 g of each of the above epoxy resin compositions was precisely weighed and formed into a tablet. Then, put this in the pot of the Koka type flow tester,
The measurement was performed with a load of 0 kg. The melt viscosity of the sample was determined from the moving speed of the piston when the molten epoxy resin composition was extruded through a die hole (diameter 1.0 mm × 10 mm).

[Moldability] Gold wire flow Using the epoxy resin compositions obtained in the above Examples and Comparative Examples, transfer molding of semiconductor elements was performed (conditions: 17).
(5 ° C. × 90 seconds) and post-curing at 175 ° C. × 5 hours to obtain a semiconductor device. This semiconductor device is a QFP
(Size: 28 × 28 × thickness 3 mm), copper lead frame, die pad size 13 × 13 mm,
The chip size is 12.5 × 12.5 mm.

That is, at the time of manufacturing the above-described semiconductor device, as shown in FIG. 2, a gold wire 14 was attached to the QFP package frame having the 13 mm square die pad 10 used above, and the above-described epoxy resin composition was used. A package was produced by resin sealing with a material. In FIG. 2, 15 is a semiconductor chip, and 16 is a lead pin.
Then, using the soft X-ray analyzer, the produced package was measured for the amount of flowing gold wire. The measurement was performed by selecting 10 gold wires from each package and measuring them, as shown in FIG.
The flow amount of the gold wire 14 from the front direction was measured.
The value of the maximum flow rate of the gold wire 14 was defined as the flow rate (dmm) of the gold wire of the package, and the flow rate of the gold wire ((d / L) × 100) was calculated. Note that L
Indicates the distance (mm) between the gold wires 14. Five packages were measured for each epoxy resin composition, and the average value was defined as the amount of gold wire flow.

Die Shift A semiconductor device was manufactured under the same conditions as the flow of the gold wire.
That is, a QFP package 11 having a 13 mm-square die pad 10 having a semiconductor chip 15 mounted thereon and having the shape shown in FIG. 4 is formed, and this package 11 is cut (indicated by a dashed-dotted line). The surface was observed, and the amount of deformation of the die pad was measured based on the difference from the design value of the die pad. That is, as shown in FIG. 5A, the thickness (thickness a μm) of the resin layer under the four corners of the die pad 10 was measured for the package in which the die pad shift occurred. On the other hand, as shown in FIG. 5B, in a package in a normal state where no die pad shift occurs,
The thickness (thickness bμ) of the resin layer below the four corners of the die pad 10
m) was measured. Such a measurement is performed at all four corners of the die pad 10, and the difference between these measured values and the normal product (a-
b) was obtained as an absolute value, and this was shown as an average value.

Generation of Void A semiconductor device was manufactured in the same manner as described above. With respect to this semiconductor device, generation of voids was examined using a soft X-ray analyzer and an ultrasonic flaw detector. The number of voids was determined by examining the number of voids having a diameter of 0.3 mm or more in 20 semiconductor devices.

Length of Air Vent Burr In the manufacture of the above semiconductor device, each mold having a slit with a groove depth of 25 μm at each corner of the obtained package is used, and the package is mounted under the same conditions as above. Molded. At this time, the flow length of the epoxy resin composition flowing into the groove was measured and defined as the air vent burr length.

Continuous Formability The above semiconductor device was continuously formed, and dirt on the package surface and air vents were observed. Then, the number of times of the formation in which the dirt and the air vent were clogged was examined and displayed.

[Powder handling property] A plastic container having a diameter of 40 mm is filled with 1 kg of resin powder, a load of 1 kg is applied thereto, and the powder is heated at a temperature of 20 ° C, 25 ° C and 30 ° C.
After standing for 4 hours, the blocking state of the powder was confirmed. As a result, those in which blocking was confirmed were indicated by x, and those in which blocking was not confirmed were indicated by ○.

[Solder Resistance] Using the above semiconductor device, after absorbing moisture under the following conditions (a) and (b), an evaluation test of infrared reflow (condition: 240 ° C. × 10 seconds) (solder resistance) Was done. Then, the number of cracks (20
Was measured. (A) 85 ° C./60% RH × 168 hours (b) 85 ° C./85% RH × 168 hours

The results of these evaluations are also shown in Tables 4 and 5 below.

[0072]

[Table 4]

[0073]

[Table 5]

From the above Tables 4 and 5, the products of Examples have good fluidity from the values of spiral flow, gel time and flow tester viscosity, and are evaluated in terms of gold wire flow, die shift, generation of voids and the like. Good results were obtained. In addition, excellent evaluation results were obtained in the solder resistance test and the TCT test. In addition, it shows excellent properties in continuous formability. On the other hand, in the comparative example product, it was found that a product satisfying both moldability and solder resistance at the same time was not obtained.

Further, when preparing the epoxy resin composition in Example 1, a phenol resin and butadiene rubber particles were preliminarily mixed. Otherwise, Example 1
In the same manner as in the above, an epoxy resin composition was obtained. As a result of performing the same measurement and evaluation as described above using this epoxy resin composition, more excellent measurement and evaluation results were obtained.

[0076]

As described above, the present invention relates to a semiconductor containing the mixture of the specific epoxy compound (component A) and the three kinds of fused silica powders having different average particle diameters as described above (component C). It is an epoxy resin composition for sealing. For this reason, while having excellent solder resistance, even if the fused silica powder is set to a high filling, good fluidity can be secured, and excellent moldability can be obtained. Therefore, by encapsulating a semiconductor element using the epoxy resin composition for encapsulating a semiconductor, a semiconductor device having excellent reliability such as solder resistance and storage resistance can be obtained.

Further, by using a phenol resin represented by the general formula (2) as the phenol resin,
Low moisture absorption and low high temperature flexural modulus can be obtained, and excellent solder resistance can be obtained.

By using butadiene-based rubber particles together with the above components as the epoxy resin composition for semiconductor encapsulation, the epoxy resin composition becomes more excellent in low stress properties.

Further, when the average roundness of the mixture of the fused silica powder is 0.7 or more, more excellent fluidity can be obtained.

[0080]

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory diagrams showing a method for measuring the roundness of a fused silica powder as an inorganic filler.

FIG. 2 is a front view showing a package used for measuring a gold wire flow amount.

FIG. 3 is an explanatory diagram showing a method of measuring a gold wire flow rate.

FIG. 4 is a front view showing a package used for measuring a die shift amount.

FIG. 5 is an explanatory view showing a method of measuring a die shift;
(A) is a sectional view showing a state where a die shift has occurred, and (b) is a sectional view showing a normal state.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/31 (72) Inventor Shinya Akizuki 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F term (reference) 4J036 AD07 AF06 AF08 AF16 AF27 AF36 FA05 FB05 FB06 JA07 4M109 AA01 BA01 CA21 EA03 EA06 EB03 EB04 EB06 EB07 EB08 EB13 EB16 EB19 EC01 EC03 EC05

Claims (7)

[Claims] 1. An epoxy resin composition for semiconductor encapsulation comprising the following components (A) to (C): (A) A biphenol (a1) represented by the following general formula (1) and a polyhydric phenol (a2) other than the biphenol (a1) are mixed in a weight mixing ratio (a1 / a2).
An epoxy compound obtained by subjecting a mixed polyhydric phenol obtained by mixing at a ratio of 1 / a2 = 5/95 to 40/60 to epihalohydrin by addition reaction and ring closure reaction. Embedded image (B) a phenolic resin. (C) A mixture of three types of fused silica powder having the following average particle diameters (x), (y) and (z), wherein the fused silica powder having the above average particle diameter (x) is 50% of the total mixture. ~
92% by weight, 5 to 40% by weight of the fused silica powder having the above average particle size (y), the above average particle size (z)
Is from 3 to 15% by weight of the total mixture
Is set to (X) Average particle size of 20 to 60 μm. (Y) The average particle diameter of the fused silica powder selected and used from those having an average particle diameter of 20 to 60 μm as described in (x) above is α
, The average particle size represented by 0.1α ≦ average particle size (μm) ≦ 0.2α. (Z) The average particle diameter of the fused silica powder selected and used from those having an average particle diameter of 20 to 60 μm described in (x) above is α
Where 0.01α ≦ average particle size (μm) <0.1α
Average particle size represented by 2. The semiconductor encapsulation according to claim 1, wherein the polyhydric phenol other than the biphenol represented by the general formula (1) used for producing the epoxy compound as the component (A) is a cresol novolak resin. An epoxy resin composition for stopping. 3. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the phenol resin as the component (B) is a phenol resin represented by the following general formula (2). Embedded image 4. The content of the mixture of the fused silica powder as the component (C) is 80 to 9 in the whole epoxy resin composition.
The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 3, which is set to 0% by weight. 5. The epoxy resin composition for semiconductor encapsulation according to claim 1, comprising butadiene rubber particles together with the components (A) to (C). 6. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the fused silica powder mixture as the component (C) has a roundness of 0.7 or more. 7. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition for semiconductor encapsulation according to claim 1.