JP2003286328A - Epoxy resin composition for sealing semiconductor and single side sealed type semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for sealing semiconductors which enables carrying out sealing molding by transfer molding with no fear of coating an outer contact terminal on the surface of a substrate with a resin flowing out of an air vent. <P>SOLUTION: The epoxy resin composition for sealing semiconductors comprises an epoxy resin, a curing agent, an inorganic filler, and a curing accelerator as the essential components, and is used for effecting sealing molding of a semiconductor element on a single side of a substrate 2 on which a semiconductor element is mounted by transfer molding. The length for the resin composition to flow out of the air vent 20 having a width of 0.75 mm and a thickness of 0.03 mm formed in a transfer mold 13 in transfer molding is ≤1 mm and, simultaneously, the gel time at 170°C is 8-30 sec. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an epoxy resin composition for semiconductor encapsulation used for encapsulation molding by transfer molding on only one surface of a substrate on which a semiconductor element is mounted, and the epoxy resin composition. The present invention relates to a single-sided sealed semiconductor device that is molded by sealing.

[0002]

2. Description of the Related Art In recent years, as the number of input / output terminals has increased due to the improvement in the degree of integration of semiconductor elements and the miniaturization and thinning of semiconductor packages mounting semiconductor elements have progressed, semiconductor devices have been replaced by conventional SOP (Small Outline Package) and QFP
(Quad Flat Package) and other types with external connection terminals arranged on the periphery of the package,
The type is migrating to a type in which external connection terminals are arranged in an array, represented by a BGA (Ball Grid Array).

A typical example of this BGA is OMPAC.
There is a so-called (Over Molded Pad Grid Carrier) method (see Patent Document 1, etc.). For example, as shown in FIG. 3, the semiconductor element 3 is mounted on a semiconductor mounting substrate 2 having a metal wiring pattern 1 by an adhesive agent 4 or the like, and the semiconductor element 3 is mounted by a gold wire 5 on the metal wiring pattern 1 of the substrate 2. Is electrically connected to, and the epoxy resin for semiconductor encapsulation is transfer-molded on only one surface of the substrate 2 on which the semiconductor element 3 is mounted and encapsulating with the encapsulating resin 6. Then, this is electrically connected to a mother board or the like by a solder ball 7 provided in parallel on the surface opposite to the sealing surface of the substrate 2 in an array form and mounted.

The following various problems have been pointed out in such a single-sided sealing type semiconductor device in which resin is sealed only on one side of the substrate. That is, the linear expansion coefficient of the substrate, the semiconductor element mounted on the substrate, the epoxy resin composition used for encapsulation and the cured product thereof, in the process of cooling from a high temperature during encapsulation molding to room temperature. Due to the difference, there is a problem that the one-side sealed semiconductor device is easily warped and deformed.

Further, when electrically connecting the one-side sealed semiconductor device to a mother board or the like with solder balls, the one-side sealed semiconductor device is exposed to a high temperature in a high temperature heating process called reflow in order to melt the solder balls. However, there is a problem in that the moisture absorbed in the encapsulated epoxy resin composition is vaporized and expanded by the action of this high temperature, which may cause cracks in the package.

Furthermore, the number of connection terminals is increased due to high integration, and accordingly, the gold wires are densely arranged,
When the gold wire is deformed by the flow of the epoxy resin composition at the time of transfer molding and sealing molding, there is a problem that a defect in which the gold wires contact each other may occur.

Therefore, as an epoxy resin composition for one-sided encapsulation, the glass transition temperature after molding and curing is higher than the encapsulation molding temperature, and the content of the inorganic filler is increased to increase the linear expansion coefficient of the cured product. Has been devised such that it is close to a semiconductor element or a substrate on which the semiconductor element is mounted, and at the same time, the moisture absorption rate is lowered, and further, a material having a low melt viscosity during transfer molding is used.

Recently, even a group of BGAs has the above-mentioned O
Various systems other than the MPAC system have been developed, and for example, there is an E-BGA as shown in FIG. 4 (see Patent Document 2, etc.). This is one in which the semiconductor element 3 is arranged in the opening 9 of the substrate 2 and the back surface of the semiconductor element 3 is exposed so that the heat dissipation characteristics from the semiconductor element 3 are greatly improved. In such a single-sided sealed semiconductor device, the semiconductor element 3 is connected to the lead terminal 10 by the gold wire 5.
Since the external connection terminals 11 to which the solder balls 7 are connected are formed on the same surface of the substrate 2, the surface on which the external connection terminals 11 are arranged and the semiconductor element 3 are sealed with the sealing resin 6. The stop surface is on the same side. Further, in the single-sided sealing type semiconductor device of such a system, the external connection terminal 11 has only a few millimeters of the area for sealing the semiconductor element 3 with the sealing resin 6 in order to increase the number of terminals, reduce the size, and reduce the thickness. It is often provided even in the vicinity of.

[0009]

[Patent Document 1] Japanese Patent Laid-Open No. 10-284641

[Patent Document 2] Japanese Patent Laid-Open No. 2000-216284

[0010]

When the above-mentioned single-sided sealing type semiconductor device is transfer molded and sealed, air is released between the surface of the substrate for sealing and the transfer molding die. Although the air vent of is formed, when the epoxy resin composition flows out from this air vent even for only a few millimeters and bleeds, the external connection terminal is covered and blocked by the epoxy resin composition, and There is a problem that a conduction failure may occur.

The present invention has been made in view of the above points, and the sealing molding can be performed by the transfer molding without fear of covering the external connection terminals on the surface of the substrate with the resin flowing out to the air vent. The purpose of the present invention is to provide an epoxy resin composition for semiconductor encapsulation, which also has low warpage deformation and high reflow resistance,
It is an object of the present invention to provide an epoxy resin composition for single-sided encapsulation that can obtain a single-sided encapsulation type semiconductor device in which deformation of a gold wire is small.

[0012]

An epoxy resin composition for semiconductor encapsulation according to claim 1 of the present invention contains an epoxy resin, a curing agent, an inorganic filler, and a curing accelerator as essential components, and a semiconductor element is An epoxy resin composition for semiconductor encapsulation used for encapsulation molding by transfer molding on one surface of a mounted substrate, wherein air having a width of 0.75 mm and a thickness of 0.03 mm formed in a transfer molding die. The length that flows out from the vent during transfer molding is 1
mm or less and gel time at 170 ° C. is 8 seconds to
It is characterized by being 30 seconds.

A second aspect of the present invention is characterized in that, in the first aspect, the gel time at 170 ° C. is 14 seconds to 30 seconds.

The invention of claim 3 is the same as in claim 1 or 2, wherein the cured product has a glass transition temperature of 170 ° C to 250 ° C.
And a coefficient of linear expansion at a temperature below the glass transition temperature is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.6 × 10 ⁻⁵ (1
/ ° C.).

According to a fourth aspect of the present invention, in the third aspect, the linear expansion coefficient of the cured product at a temperature not higher than the glass transition temperature is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.3 × 10 ^{−. 5} (1
/ ° C.).

According to the invention of claim 5, in any one of claims 1 to 4, the melt viscosity at 175 ° C. is 1 Pa.
-S to 100 Pa-s.

The invention of claim 6 is the same as in claim 5, wherein the melt viscosity at 175 ° C. is 10 Pa · s to 80 P.
The epoxy resin composition for semiconductor encapsulation according to claim 5, wherein the epoxy resin composition is a · s.

Further, the invention of claim 7 is characterized in that, in any one of claims 1 to 6, an imidazole compound is used as a curing accelerator.

The invention of claim 8 is based on any one of claims 1 to 7, wherein at least a part of the epoxy resin is represented by chemical formula (A), chemical formula (B), chemical formula (C) and chemical formula (D). And one or more selected from the phenolic resins represented by the chemical formulas (E), (F) and (G) as a curing agent. It is a feature.

[0020]

[Chemical 3]

(In the chemical formula (C), n is an integer of 1 to 4. The epoxy resin of the chemical formula (D) is a mixture of the chemical formulas D1 and D2 in a mass ratio of 50:50.)

[0022]

[Chemical 4]

(In the chemical formula (E), n is an integer of 0 to 3. In the chemical formula (F), n is an integer of 1 to 4. In the chemical formula (G), n is an integer of 0 to 3.)
The invention according to claim 9 is the epoxy resin represented by chemical formula (A) according to claim 8 and chemical formulas (B) to
It is characterized in that it is used in combination with an epoxy resin selected from one or more of the epoxy resins represented by (D).

Further, the invention of claim 10 is defined by claims 1 to 8.
In any one of the above, the content of the inorganic filler is 80% by mass to 95% by mass of the total amount of the composition.

According to an eleventh aspect of the present invention, in a single-sided sealed semiconductor device, a semiconductor element is mounted on one side of a substrate,
The epoxy resin composition according to any one of claims 1 to 10 is formed by transfer molding and sealing.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

The epoxy resin composition for encapsulating a semiconductor according to the present invention contains an epoxy resin, a curing agent, an inorganic filler and a curing accelerator as essential components, and is transfer molded to form one side of a semiconductor mounting substrate. A single-sided sealing type semiconductor device is manufactured by resin-sealing only. Transfer molding has an advantage that a large number of semiconductor elements can be sealed at one time, and is currently most widely used in the sealing molding of semiconductor elements. When sealing and molding the epoxy resin composition by transfer molding, the molding temperature (temperature of the molding die) is set to 160 ° C to 185 ° C in order to sufficiently cure the epoxy resin. Further, in order to sufficiently fill the molding die with the epoxy resin, the clamping pressure of the molding die is set to 5 MPa or more, and the transfer pressure is set to 4 MPa to 8 MPa.

FIG. 1 shows an example of the transfer molding die 13, which is formed by a pair of mold bodies 14 and 15. A substrate setting recess 16 is provided in the upper surface of the lower mold body 14, and a sealing molding cavity 17 is provided in the lower surface of the upper mold body 15. Also the mold 14,
A pot portion 18 that opens upward is formed between 15 and the pot portion 18 and the sealing molding cavity 17 are made to communicate with each other by a runner 19 provided on the lower surface of the mold body 15. is there. Further, at the end portion on the side opposite to the communication point with the runner 19, the cavity 17 for sealing and molding is formed.
An air vent 20 communicating with the mold body 15 is provided on the lower surface of the mold 15. The air vent 20 has a width W = 0.75 mm and a thickness D = 0.03 mm, and is opened on the outer surface of the transfer molding die 13. When performing the sealing molding with the transfer molding die 13, the substrate 2 on which the semiconductor element 3 is adhered on one side with the adhesive 4 is mounted and set in the substrate setting concave portion 16 of the molding body 14, The semiconductor element 3 is arranged in the sealing molding cavity 17 of the mold body 15 by clamping the mold body 15 to the mold 14. When the mold is clamped in this way, the air vent 20 is arranged along the surface of the substrate 2.

Then, by charging the epoxy resin composition into the pot portion 18 and pressurizing it with the plunger 21, the epoxy resin composition is filled in the sealing molding cavity 17 through the runner 19, as shown in FIG. It is possible to mold a one-side sealed semiconductor device in which only one surface of the substrate 2 on which the semiconductor element 3 is mounted is sealed with the sealing resin 6. Further, in the one-side sealed semiconductor device molded in this way,
When the epoxy resin composition flows out from the encapsulation molding cavity 17 into the air vent 20 and bleeds, the epoxy resin composition flows through the air vent 20 along the surface of the substrate 2, and thus the air vent burr 22 that has flowed out to the air vent 20. Is coated on the surface of the substrate 2 at the periphery of the sealing resin 6.

Therefore, in the present invention, when the transfer molding is carried out under the above-mentioned molding temperature and transfer pressure, the cavity 17 for sealing molding is formed in the air vent 20.
The epoxy resin composition is prepared so that the length L flowing out from and bleeding is 1 mm or less. When the length L flowing out into the air vent 20 and bleeding is 1 mm or less, the surface of the external connection terminal provided on the surface of the substrate 2 in the vicinity of the sealing region is prevented from being covered with the air vent burr 22. Therefore, it is possible to prevent defective electrical connection of the one-side sealed semiconductor device to the mother board or the like. The shorter the length L that flows out from the sealing molding cavity 17 and bleeds, the more preferable, and ideally L = 0 mm.

The epoxy resin composition of the present invention has a gel time at 170 ° C. of 8 seconds to 30 seconds, more preferably 14 seconds to 30 seconds, and most preferably 1
The thing of 4 seconds-26 seconds is used. By using an epoxy resin composition having a gel time at 170 ° C. of 30 seconds or less, more preferably 26 seconds or less, the length L that flows out into the air vent 20 and bleeds during transfer molding can be 1 mm or less. It is a thing. The gel time of the epoxy resin composition at 170 ° C is 3
When it is 0 seconds or less, more preferably 26 seconds or less, the time required for curing the epoxy resin composition in transfer molding is shortened, and there is also an effect that the molding cycle of transfer molding can be shortened and productivity can be improved. However, if the gel time of the epoxy resin composition is too short, the filling property of the epoxy resin composition into the cavity 17 for sealing and molding may be deteriorated, which may cause defective filling. Therefore, the gel time at 170 ° C. is 8 seconds. It is preferably not less than 14 seconds, more preferably not less than 14 seconds.

In the epoxy resin composition of the present invention, the cured product has a glass transition temperature (Tg) of 170 ° C. to 250 ° C., which is higher than the transfer molding temperature, and a coefficient of linear expansion at a temperature not higher than the glass transition temperature ( α ₁ ) is 0.7
× preferably used ¹⁰ -5 (1 / ℃) ^~1.6 what is ^{× 10 -5 (1 / ℃)} . The linear expansion coefficient (α ₁ ) at a temperature below the glass transition temperature is 0.7 × 10 ⁻⁵ (1 /
C.) to 1.3 × 10 ⁻⁵ (1 / ° C.), more preferably 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.0 × 10
Most preferably, it is ⁻⁵ (1 / ° C.). By using a cured product having a glass transition temperature and a linear expansion coefficient in this range, warp deformation of the one-side sealed semiconductor device after the one-side sealed semiconductor device is cooled from the molding temperature to room temperature is reduced. Is something that can be done.

That is, as the substrate 2 used for the single-sided sealing type semiconductor device, a glass-based bismaleimide resin substrate or a glass-based epoxy resin substrate is generally used, and the linear expansion coefficient of these is usually 1.0 ×. 10 ^-5 (1 / ° C) ~
It is about 1.7 × 10 ⁻⁵ (1 / ° C.), and by using the epoxy resin composition of the present invention having a glass transition temperature of the cured product within the above range, the substrate 2 and the epoxy resin composition are sealed. The warp deformation caused by the difference in the linear expansion coefficient of the stop resin 6 can be reduced. The linear expansion coefficient referred to here is 80 to 1 obtained by using a linear expansion coefficient measuring device (“DILATRONIC” manufactured by Tokyo Kogyo Co., Ltd.).
It refers to a linear expansion coefficient of 20 ° C. Further, the physical properties of the cured product of the resin composition greatly change at temperatures above the glass transition temperature. However, if the glass transition temperature is above the transfer molding temperature, the cured product of the molded product after transfer molding is performed on one side. Since a large change in the physical properties does not occur until the semiconductor device is taken out, it is possible to reduce the occurrence of warpage of the one-side sealed semiconductor device.

Further, the epoxy resin composition of the present invention has a melt viscosity at 175 ° C. of 1 Pa · s to 100 P.
It is preferable to use the one having a · s, more preferably 10 Pa · s to 80 Pa · s. By using an epoxy resin composition having a melt viscosity at 175 ° C. of 100 Pa · s or less, particularly 80 Pa · s or less, when the transfer molding is performed by the transfer molding die 13 having the above molding temperature, the semiconductor element 3 and the substrate 2 are It is possible to reduce the deformation of the gold wire 5 for electrically connecting the. If the melt viscosity is too low, the length of the material flowing out into the air vent 20 and bleeding may be longer than 1 mm. Therefore, the melt viscosity at 175 ° C. is preferably 1 Pa · s or more, particularly 10 Pa · s or more. . The melt viscosity referred to here is the viscosity at 175 ° C. obtained using a Koka type flow tester (“CFT-100C” manufactured by Shimadzu Corporation).

In the epoxy resin composition according to the present invention, as the epoxy resin, for example, biphenyl type epoxy resin, bisphenol type epoxy resin, biphenyl novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, etc. are used. However, the above chemical formulas (A) to (D)
It is preferable to use one or more selected from the epoxy resins represented by.

Among the epoxy resins represented by the chemical formulas (A) to (D), the epoxy resin represented by the chemical formula (A) and one or more kinds selected from those represented by the chemical formulas (B) to (D) are selected. It is preferable to use them in combination. By using the epoxy resin represented by the chemical formula (A), it becomes easy to adjust the glass transition temperature of the cured product of the epoxy resin composition to 170 ° C. or higher, and the epoxy resin represented by the chemical formula (B), ( By using the compounds represented by C) and (D), it becomes easy to adjust the melt viscosity of the epoxy resin composition at 175 ° C. to 100 Pa · s or less, particularly 80 Pa · s or less. When the epoxy resin of the chemical formula (A) and the epoxy resins of the chemical formulas (B) to (D) are used together, the ratio of the epoxy resin of the chemical formula (A) and the epoxy resin selected from the chemical formulas (B) to (D) is (A): [(B) to (D)] = 95: 5 to 50: 5
It is preferable to set the mass ratio in the range of 0, and the most preferable range is (A): [(B) to (D)] = 70:30. The blending amount of the epoxy resin is not particularly limited, but it is preferably set in the range of 2.0% by mass to 16.0% by mass based on the total amount of the composition.

In the epoxy resin composition according to the present invention, a phenol novolac resin, a cresol novolac resin, a biphenyl novolac resin, a phenol aralkyl resin, a bisphenol resin or the like can be used as a curing agent, and the above-mentioned chemical formula (E ) To (G), it is preferable to use one or more selected from the phenolic resins. By using the phenolic resin represented by the chemical formulas (E) to (G) as the curing agent, it becomes easy to adjust the glass transition temperature of the cured product of the epoxy resin composition to 170 ° C. or higher. The compounding amount of the curing agent is not particularly limited, but it is preferably set in the range of 1.0% by mass to 5.0% by mass with respect to the total amount of the composition.

In the epoxy resin composition according to the present invention, it is preferable to use an imidazole compound as a curing accelerator. Examples of the imidazole compound include 2-phenylimidazole and 2-phenyl-4,5-dihydroxymethylimidazole. The imidazole compound can be used alone or in combination of two or more kinds. The imidazole compound can be a single substance or a reaction product of the imidazole compound and the phenol novolac resin. . By thus using the imidazole compound as a curing accelerator, the epoxy resin composition at 170 ° C.
It is easy to adjust the gel time at 30 seconds or less, particularly 26 seconds or less. The compounding amount of the curing accelerator is not particularly limited, but it is preferably set in the range of 0.1% by mass to 1.0% by mass with respect to the total amount of the composition.

Further, in the epoxy resin composition according to the present invention, as the inorganic filler, fused silica, crystalline silica,
Powders of alumina, silicon nitride, aluminum nitride and the like can be used, and among these, fused silica is most preferable. And it is preferable to set the compounding quantity of this inorganic filler in the range of 80 mass% -95 mass% in the whole composition. By setting the compounding amount of the inorganic filler in this range, the cured product of the epoxy resin composition has a linear expansion coefficient of 0.
7 × 10 ^-5 (1 / ° C) to 1.6 × 10 ^-5 (1 / ° C)
Range of 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.3 × 1
0 range of ^-5 (1 / ℃), further 0.7 × ¹⁰ -5 (1
/ ° C) to 1.0 x 10 ^-5 (1 / ° C).

The epoxy resin composition of the present invention comprises the above-mentioned epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and if necessary, a flame retardant, a release agent, carbon black, a coloring agent such as an organic dye and the like. Blend and mix each of these ingredients with a mixer,
It can be prepared by uniformly mixing with a blender or the like and then kneading with a heating roll, a kneader or the like. The mixing order of each component is not particularly limited, and after kneading, the mixture is cooled and solidified, and this is crushed and powdered, or the powder is tableted and molded into a tablet. It is something that can be offered.

[0041]

EXAMPLES Next, the present invention will be specifically described with reference to examples.

Examples 1 to 10 were prepared by mixing the components of the formulation shown in Table 1 with a mixer until they were sufficiently homogeneous, kneading with a heating roll for 5 minutes, cooling and solidifying the kneaded product, and then pulverizing with a pulverizer. And the epoxy resin composition of Comparative Examples 1-4 was prepared.

The components of Table 1 are as follows. -Epoxy resin of chemical formula (A): "VG3" manufactured by Mitsui Chemicals, Inc.
101L "-Epoxy resin of chemical formula (B):" YDC "manufactured by Tohto Kasei Co., Ltd.
1312 "・ Epoxy resin of chemical formula (C):" CE "manufactured by Nippon Kayaku Co., Ltd.
R3000L "-Epoxy resin of chemical formula (D):" YL6121H "manufactured by Japan Epoxy Co., Ltd.-Phenolic resin of chemical formula (E):" M "manufactured by Meiwa Kasei Co., Ltd.
EH7500SS "-Phenolic resin of chemical formula (F): Meiwa Kasei's" M "
EH7851SS "-phenolic resin of chemical formula (G): Meiwa Kasei Co., Ltd." D
L92 "-Orthocresol novolac epoxy resin: Sumitomo Chemical Co., Ltd." ESCN195XL "-Biphenyl epoxy resin: Japan Epoxy" X
Y4000H "-Phenol novolac resin:" H-1 "manufactured by Meiwa Kasei Co., Ltd.-Phenol aralkyl resin:" HE "manufactured by Sumitomo Chemical Co., Ltd.
100C15 "・ 2-Phenyl-4,5-dihydroxymethylimidazole:" 2PHZ "manufactured by Shikoku Chemicals ・ 2-Phenylimidazole:" 2PZ "manufactured by Shikoku Chemicals ・ Fused silica: average particle size 15 μm ・ Coupling agent: γ- Mercaptopropyltrimethoxysilane

[0044]

[Table 1-1]

[0045]

[Table 1-2]

The epoxy resin compositions of Examples 1 to 10 and Comparative Examples 1 to 4 prepared as described above were heated to 170 ° C.
The gel time, the glass transition temperature of the cured product, the coefficient of linear expansion below the glass transition temperature, and the melt viscosity at 175 ° C. were measured. Here, the measurement of gel time at 170 ° C.
Curalast meter (CUREL manufactured by Orientec
ASTOMETER V "). Further, the glass transition temperature of the cured product and the measurement of the linear expansion coefficient at the glass transition temperature or less are obtained by curing the epoxy resin composition under the same conditions as those of the transfer molding described below and after curing under the same conditions. Was measured by determining the expansion curve using a linear expansion coefficient measuring device (“DILATRONIC” manufactured by Tokyo Kogyo Co., Ltd.), and the inflection point was defined as the glass transition temperature, and the thermal expansion coefficient of 80 to 120 ° C. was calculated. Furthermore, the melt viscosity at 175 ° C. is measured by a high-performance flow tester (“CF manufactured by Shimadzu Corporation”
T-100C "). The results of these measurements are shown in Table 2.

Next, using the epoxy resin compositions of Examples 1 to 10 and Comparative Examples 1 to 4, a transfer molding die 13 having an air vent 20 having a width of 0.75 mm and a thickness of 0.03 mm shown in FIG. Transfer molding was performed. Here, the size of the substrate 2 is 35 mm × 35 mm × 0.
Substrate 2 using a 4 mm glass base bismaleimide triazine resin substrate (“BT-832” manufactured by Mitsubishi Gas Chemical Co., Inc.)
A semiconductor device 3 having a size of 7.6 mm × 7.6 mm × 0.35 mm is mounted on one surface of the substrate with an adhesive 4 (“Able Stick 8361J” manufactured by Ablebond Co., Ltd.), and a concave portion 16 for substrate setting of the mold body 14 is formed. I set it by fitting it in.
Then, the mold bodies 14 and 15 are clamped with a mold clamping pressure of 5 MPa, and then the pot resin 18 is charged with the epoxy resin composition,
It was pressed by the plunger 21 and sealed and molded. At this time,
The mold bodies 14 and 15 and the plunger 21 are heated to 170 ° C. to set the molding temperature to 170 ° C., the pressure of the plunger 21 is adjusted to 4 MPa and the transfer pressure is set to 4 MPa, and it takes about 10 seconds. The epoxy resin composition was filled in the sealing molding cavity 17. After this, 8
Cure for 0 seconds and transfer mold 1
After being taken out from the substrate 3, after-curing at 175 ° C. for 6 hours, a one-side sealed semiconductor device in which one side of the substrate 2 on which the semiconductor element 3 is mounted is sealed with a sealing resin 6 as shown in FIG. Obtained.

The length L of the air vent burr 22 flowing out to the air vent 20 was measured for the one-side sealed semiconductor device thus obtained. The amount of warp deformation was evaluated for the single-sided sealed semiconductor device. The amount of warp deformation was measured by measuring the contour of the lower surface of the substrate 2 using a surface roughness meter, and the maximum value of the height difference was defined as warp deformation. Further, the reflow resistance of the single-sided sealed semiconductor device was evaluated. The reflow resistance is measured by pre-drying the single-sided sealed semiconductor device at 125 ° C. for 24 hours, and then moisture absorption for 168 hours in a thermo-hygrostat set at 85 ° C. and 60% RH. After that, a reflow process was performed using a hot-air combined far-infrared reflow furnace set to a peak temperature of 245 ° C., and the single-side sealed semiconductor device after the reflow process was subjected to an ultrasonic probe (Hitachi Construction Machinery Co., Ltd.). By observing the inside using "mi-scope" manufactured, the presence or absence of peeling at the interface between the sealing resin 6 and the semiconductor element 3 and at the interface between the sealing resin 6 and the substrate 2 is checked. This was carried out for 10 pieces to evaluate the number of peeling occurrences, and these results are shown in Table 2.

[0049]

[Table 2]

As can be seen from Table 2, the epoxy resin compositions of the respective examples had a gel time at 170 ° C. of 30 seconds or less, and an outflow length to the air vent 20 during transfer molding of 1 mm or less. Moreover, it is confirmed that the single-sided sealing type semiconductor device which is molded by using the epoxy resin composition of each example has a small warp deformation and a good reflow resistance.

[0051]

As described above, the epoxy resin composition for semiconductor encapsulation according to claim 1 of the present invention contains an epoxy resin, a curing agent, an inorganic filler and a curing accelerator as essential components,
An epoxy resin composition for semiconductor encapsulation, which is used for encapsulation molding on one surface of a substrate on which a semiconductor element is mounted by transfer molding, wherein a width 0.75 mm and a thickness 0. Since the length of the air vent that flows into the 03 mm air vent during transfer molding is 1 mm or less, and the gel time at 170 ° C is 8 seconds to 30 seconds, the air vent is sealed during transfer molding. The flow-out of the stop resin becomes extremely small, and the sealing molding can be performed by the transfer molding without the fear that the resin flowing out to the air vent will cover the external connection terminals on the surface of the substrate.

Further, in the invention of claim 2, in claim 1, the gel time at 170 ° C. is 14 seconds to 30 seconds, so that it is possible to better prevent the occurrence of defective filling.

The invention of claim 3 is the same as claim 1 or 2, wherein the glass transition temperature of the cured product is 170 ° C to 250 ° C.
And a coefficient of linear expansion at a temperature below the glass transition temperature is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.6 × 10 ⁻⁵ (1
/ ° C.), it is possible to reduce the warp deformation due to the difference in the linear expansion coefficient between the substrate and the sealing resin between the epoxy resin composition.

According to the invention of claim 4, in claim 3, the linear expansion coefficient at a temperature not higher than the glass transition temperature of the cured product is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.3 × 10 ^{−. 5} (1
/ ° C.), the warp deformation can be further reduced.

According to the invention of claim 5, in any one of claims 1 to 4, the melt viscosity at 175 ° C. is 1 Pa.
Since it is from s to 100 Pas, it is possible to reduce the deformation of the gold wire due to the flow of the epoxy resin composition during transfer molding.

The invention of claim 6 is the same as in claim 5, wherein the melt viscosity at 175 ° C. is 10 Pa · s to 80 P.
Since it is a · s, the deformation of the gold wire can be further reduced.

According to the invention of claim 7, in any one of claims 1 to 6, since an imidazole compound is used as a curing accelerator, the epoxy resin composition of 17
It is easy to adjust the gel time at 0 ° C. to 30 seconds or less.

The invention of claim 8 is based on any one of claims 1 to 7, wherein at least a part of the epoxy resin is selected from the epoxy resins represented by the chemical formulas (A) to (D), In addition, as the curing agent, the chemical formula (E)
Since a resin selected from the phenolic resins represented by (G) is used, it becomes easy to adjust the glass transition temperature of the cured product to 170 ° C. or higher and the melt viscosity of the epoxy resin composition at 175 ° C. is 100 Pa. It is easy to adjust to s or less, particularly 80 Ps · s or less.

Further, the invention of claim 9 is the epoxy resin selected from the epoxy resin represented by the chemical formula (A) and the epoxy resins represented by the chemical formulas (B) to (D). Since the glass transition temperature of the cured product is adjusted to 170 ° C. or higher, the melt viscosity of the epoxy resin composition at 175 ° C. is 100 Pa.
It is easier to adjust to s or less, especially 80 Ps · s or less.

The invention of claim 10 relates to claims 1 to 9.
In any of the above, since the content of the inorganic filler is 80% by mass to 95% by mass of the total amount of the composition, the linear expansion coefficient of the cured product is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.6. × 10 ^-5
(1 / ° C) range, especially 0.7 × 10 ^-5 (1 / ° C) to
It is easy to adjust to the range of 1.3 × 10 ⁻⁵ (1 / ° C.).

According to an eleventh aspect of the present invention, there is provided a single-sided sealed semiconductor device, wherein one side of a substrate on which a semiconductor element is mounted is
Since the epoxy resin composition according to any one of claims 1 to 10 is transfer molded and sealed, it is possible to prevent the external connection terminals on the surface of the substrate from being covered with the resin flowing out to the air vent. It is possible to prevent the occurrence of electrical connection failure to a motherboard, etc., and also to obtain a one-side sealed semiconductor device with less warp deformation, high reflow resistance, and less gold wire deformation. Is something that can be done.

[Brief description of drawings]

1A and 1B show an example of a transfer molding die, in which FIG. 1A is a sectional view and FIG. 1B is a side view.

FIG. 2 is a schematic cross-sectional view showing an example of a single-sided sealed semiconductor device obtained by transfer molding.

FIG. 3 is an example of an OMPAC which is an example of a single-sided sealed semiconductor device.
FIG.

FIG. 4 is an example of a single-sided sealed semiconductor device E-BGA.
FIG.

[Explanation of symbols]

2 substrates 3 Semiconductor element 6 Sealing resin 13 Transfer Mold 20 air vents

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 23/29 B29K 63:00 23/31 105: 16 // B29K 63:00 B29L 31:34 105: 16 H01L 23/30 RB29L 31:34 (72) Inventor Masayuki, 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Masashi Nakamura, 1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd. (72) Inventor Takayuki Tsuji 1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd. F-term within the company (reference) 4F202 AA39C AA39D AB03 AB11 AB16 AH37 AR12 CA12 CB01 CP01 CP05 4F206 AA39C AA39D AB03 AB11 AB16 AH37 JN12 JA02 4J002 CC04X CC05X CC06X CC12X CC27X CD02W CD05W CD06W CD07W DE147 DF017 DJ007 DJ017 EU116 FD017 FD090 FD14X FD156 GQ01 GQ05 4J036 AA01 AC02 AD01 AD07 AF07 AJ05 AK02 DB06 DC40 DC41 FB06 FB07 FB08 HA13 JA07 4M109 AA01 BA01 CA21 EA02 EB02 EB04 EB12 EC04 EC20

Claims (11)

[Claims] 1. A semiconductor encapsulation, which comprises an epoxy resin, a curing agent, an inorganic filler, and a curing accelerator as essential components, and is used for encapsulating by transfer molding on one side of a substrate on which a semiconductor element is mounted. Epoxy resin composition having a width of 0.75 m formed in a transfer molding die
m, the length that flows out to the air vent of 0.03 mm in thickness during transfer molding is 1 mm or less, and 17
An epoxy resin composition for semiconductor encapsulation, which has a gel time at 0 ° C. of 8 seconds to 30 seconds. 2. The gel time at 170 ° C. is 14 seconds to 30.
The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the epoxy resin composition is a second. 3. The glass transition temperature of the cured product is 170 ° C. to 2
The linear expansion coefficient at a temperature of 50 ° C. and below the glass transition temperature is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.6 × 10.
^-5 (1 / ° C) 3. The method according to claim 1 or 2, wherein
The epoxy resin composition for semiconductor encapsulation according to 1. 4. A linear expansion coefficient at a temperature below the glass transition temperature of the cured product is 0.7 × 10 ⁻⁵ (1 / ° C.) to 1.3 × 1.
The epoxy resin composition for semiconductor encapsulation according to claim 3, wherein the epoxy resin composition is 0 ⁻⁵ (1 / ° C.). 5. The melt viscosity at 175 ° C. is 1 Pa · s.
The epoxy resin composition for semiconductor encapsulation according to any one of claims 1 to 4, wherein the epoxy resin composition is from 100 to 100 Pa · s. 6. The melt viscosity at 175 ° C. is 10 Pa.
It is s-80 Pa * s, The epoxy resin composition for semiconductor sealing of Claim 5 characterized by the above-mentioned. 7. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein an imidazole compound is used as a curing accelerator. 8. As at least a part of the epoxy resin,
At least one selected from the epoxy resins represented by the chemical formula (A), the chemical formula (B), the chemical formula (C), and the chemical formula (D) is used, and the chemical formula (E), the chemical formula (F), and the chemical formula are used as a curing agent. The epoxy resin resin composition for semiconductor encapsulation according to any one of claims 1 to 7, wherein at least one selected from the phenolic resins represented by (G) is used. [Chemical 1] (In the chemical formula (C), n is an integer of 1 to 4. The epoxy resin of the chemical formula (D) is a mixture of the chemical formulas D1 and D2 in equal mass.) (In chemical formula (E), n is an integer of 0 to 3. In chemical formula (F), n is an integer of 1 to 4. In chemical formula (G), n is an integer of 0 to 3.) 9. An epoxy resin represented by the chemical formula (A) and an epoxy resin selected from one or more of the epoxy resins represented by the chemical formulas (B) to (D) are used in combination. 8. The epoxy resin composition for semiconductor encapsulation according to 8. 10. The content of the inorganic filler is 8 of the total amount of the composition.
It is 0 mass% -95 mass%, It is characterized by the above-mentioned.
10. The epoxy resin composition for semiconductor encapsulation according to any one of 9 to 9. 11. A single-sided seal obtained by transfer-molding and sealing the epoxy resin composition according to claim 1 on one side of a substrate on which a semiconductor element is mounted. Type semiconductor device.