JP2000022049A - Resin-sealed semiconductor device and epoxy resin composition for sealing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition which is excellent in adhesion and reliability, while enabling a resin-sealed semiconductor device to be lessened in size and improved in performance, and provide also a semiconductor device sealed up with the epoxy resin composition. SOLUTION: A semiconductor device is equipped with a semiconductor element 1, a board 2 mounted with the semiconductor element 1, and an epoxy resin composition 3 which seals up the semiconductor element 1, where the epoxy resin composition 3 is formed only on the one surface of the board 2 and contains epoxy resin, curing agent, and inorganic filler, and the physical properties of the cured epoxy resin composition are as follows; flexual modulus is 10-30 GPa at a temperature of 23 deg.C, linear expansion coefficient is 4 to 20×10-6/K in a temperature range of 23 deg.C to a glass transition temperature, the product of flexual modulus at 23 deg.C and linear expansion coefficient in a temperature range of 23 deg.C to glass transition temperature is below 3×10-4 GPa/K, and glass transition temperature is above 150 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin-sealed semiconductor device and an epoxy resin composition for sealing a resin-sealed semiconductor device. More specifically, the present invention relates to a resin-sealed semiconductor device, particularly to a semiconductor device in which a sealing resin is molded on only one surface of a substrate portion of a semiconductor device, and a sealing epoxy resin used for the device.

[0002]

2. Description of the Related Art Recent downsizing of electronic devices
Along with miniaturization, semiconductor devices are becoming smaller, thinner, and higher in performance. A conventional semiconductor device uses a semiconductor element and a lead frame, and is resin-sealed from both sides so as to cover with a resin except for a part necessary for mounting these elements on a printed circuit board. Therefore, development of miniaturization of a semiconductor device has mainly been concerned with a lead frame serving as a substrate and a sealing resin. Surface mounting technology has been developed to mount miniaturized semiconductor devices on printed circuit boards with high density. Typical semiconductor devices compatible with surface mounting technology include TSOP (Thin Small
Outline package) and Q compatible with multiple pins
FP (Quad Flat Package) and the like have been developed.

Further, in order to reduce the mounting area occupied by the semiconductor device and achieve higher performance, a semiconductor device having a structure in which terminals for connecting the semiconductor device and the motherboard are arranged on the back surface of the substrate of the semiconductor device has been developed. . In this structure, since the sealing resin is formed only on one side of the substrate, unlike a conventional double-sided molded product, the semiconductor device is likely to warp. If the amount of warpage of the semiconductor device is large, it is difficult to mount the semiconductor device on a horizontal motherboard. In addition, because of single-sided molding, when thermal stress is applied, such as in a thermal cycle test, peeling occurs at the bonding interface with the base material and the semiconductor element, which causes a failure.

[0004]

Therefore, there is a need to provide a highly reliable sealing resin which is compatible with a semiconductor device having a different form from that of the prior art, has a reduced amount of warpage, is less likely to be subjected to thermal stress, and is highly reliable. .

That is, an object of the present invention is to provide an epoxy resin composition which corresponds to a semiconductor device having a structure in which a sealing resin is molded only on one side of a substrate, reduces the amount of warpage, and has excellent thermal cycling properties. An object of the present invention is to provide a semiconductor device sealed with a resin composition.

[0006]

In order to solve the above-mentioned problems, a resin-sealed semiconductor device of the present invention mainly has the following configuration. That is, "a semiconductor device comprising a semiconductor element, a substrate on which the semiconductor element is mounted, and a cured product of an epoxy resin composition for encapsulating the semiconductor element. An epoxy resin composition is formed, and the epoxy resin composition contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C). Flexural modulus at 10 ° C. exceeds 10 GPa, 30 GPa or less, linear expansion coefficient from 23 ° C. to glass transition temperature is 4 × 10 ^{−6 to} 20 × 1.
0 ⁻⁶ / K, and the product of the flexural modulus at 23 ° C. and the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 3 × 10 ⁻⁴ GPa.
/ K or less, and the glass transition temperature of the cured product of the epoxy resin composition is 150 ° C. or more. ". The resin-sealed semiconductor device of the present invention mainly has the following configuration. That is, an epoxy resin for semiconductor device encapsulation, comprising: a semiconductor element, a substrate on which the semiconductor element is mounted, and an epoxy resin composition, wherein the epoxy resin composition is molded on only one surface of the substrate. A composition, wherein the epoxy resin composition contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C), and a cured product of the epoxy resin composition,
Flexural modulus at 23 ° C exceeds 10 GPa and 30 GPa
a, the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 4 × 10 ^{−6 to} 20 × 10 ⁻⁶ / K, the flexural modulus at 23 ° C. and the coefficient of linear expansion from 23 ° C. to the glass transition temperature Characterized in that the product of the epoxy resin composition is 3 × 10 ⁻⁴ GPa / K or less, and the glass transition temperature of the cured product of the epoxy resin composition is 150 ° C. or more. Resin composition. ".

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

As shown in FIG. 1 or 2, a semiconductor device according to the present invention comprises a semiconductor element 1, a substrate 2 on which the semiconductor element is mounted, and an epoxy resin composition 3 for encapsulating the semiconductor element. The epoxy resin composition 3 is formed only on one side of the substrate on the side where the semiconductor element is mounted. If necessary, an adhesive layer 4 can be provided between the semiconductor element 1 and the substrate 2. In addition, the substrate 2 usually penetrates through the substrate 2a, the patterned metal wiring 2c (the pattern is not shown in FIGS. 1 and 2), and the substrate 2b in order to establish electrical conduction with the outside. Then, the current supply unit 2b is partially provided. Further, a lead wiring 5 connecting the semiconductor element 1 and the metal wiring 2c can be provided.

The semiconductor device of the present invention is obtained by preparing a semiconductor device spare device having the semiconductor element 1 mounted on the substrate 2 and molding the epoxy resin composition in a mold in which the spare device is arranged. In molding, the epoxy resin composition is usually used in the form of powder, pellets or tablets. The epoxy resin composition is produced by molding the epoxy resin composition at a temperature of, for example, 120 to 250 ° C., preferably 150 to 200 ° C. by a known method such as transfer molding, injection molding, or casting.
If necessary, additional heat treatment (for example, 150 to 1
(80 ° C., 2 to 16 hours).

In the present invention, the material used for the substrate 2a is not particularly limited. However, since heat generated by driving the semiconductor element is released, a material having good heat radiation characteristics must be used. In addition, in order to extract an increasing number of external electrodes and a signal for increasing the speed, it is necessary to form a wiring pattern having a narrow pitch. To cope with this, it is necessary to use a material having a low dielectric constant. As such a material, ceramic, synthetic resin, epoxy, bismaleimide olazine, and polyimide are preferable.

The cured product of the epoxy resin composition of the present invention has a flexural modulus at 23 ° C. of more than 10 GPa and 30 G
Pa or less, the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 4 × 10 ^{−6 to} 20 × 10 ⁻⁶ / K, preferably 4 × 10 ⁻⁶ / K.
× 10 ^{−6 to} 16 × 10 ⁻⁶ / K, particularly preferably 8 × 10
^{−6 to} 16 × 10 ⁻⁶ / K, and the product of the flexural modulus at 23 ° C. and the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 3
× 10 ^-4 GPa / K or less, and a glass transition temperature of 15
The temperature is 0 ° C or higher, preferably 170 ° C or higher.

Only when the cured product of the epoxy resin composition satisfies the physical properties in this range, a semiconductor device having small internal stress and high reliability can be obtained. When the linear expansion coefficient in the glassy region is larger than 20 × 10 ⁻⁶ / K,
The amount of warpage of the semiconductor device is large, and mounting on a printed circuit board becomes difficult. If the coefficient of linear expansion is smaller than 4 × 10 ⁻⁶ / K, peeling is likely to occur at the interface between the resin and the substrate, resulting in poor thermal cycling.

If the flexural modulus is greater than 30 GPa, the adhesion between the sealing resin and the substrate or semiconductor element is reduced. As a result, the thermal cycle test results are defective.
When the flexural modulus is 10 GPa or less, workability is poor.

Further, the cured product of the epoxy resin composition has
Flexural modulus at ℃ exceeds 10 GPa and 30 GPa or less,
The coefficient of linear expansion from 23 ° C to the glass transition temperature is 4 × 10
^{-6 to} 20 × 10 ⁻⁶ / K, when the product of the flexural modulus at 23 ° C. and the linear expansion coefficient from 23 ° C. to the glass transition temperature exceeds 3 × 10 ⁻⁴ GPa / K. The amount of warpage of the semiconductor device is large.

Further, when the glass transition temperature is lower than 150 ° C., the warpage of the semiconductor device increases.

The term "cured product" as used herein means the epoxy resin composition of the present invention at a temperature of, for example, 120 to 250 ° C., preferably 150 to 200 ° C., by a known method such as transfer molding, injection molding and casting. Molding and, if necessary, additional heat treatment (eg, 150-180 ° C.,
2 to 16 hours), and usually the chemical reaction of the epoxy group is almost completed, or the physical properties of the epoxy resin composition have almost reached saturation.

The epoxy resin composition of the present invention comprises:
Epoxy resin (A) is blended. Such a material is not particularly limited as long as it has two or more epoxy groups in one molecule.

For example, cresol novolak type epoxy resin, phenol novolak type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, various novolak type epoxy resins synthesized from bisphenol A or resorcin, linear aliphatic epoxy resin, fatty acid A cyclic epoxy resin, a heterocyclic epoxy resin, a halogenated epoxy resin and the like can be mentioned. Further, two or more epoxy resins may be used in combination.

The epoxy resin composition of the present invention contains a curing agent (B). Such a resin is not particularly limited as long as it reacts with the epoxy resin (A) to be cured, and specific examples thereof include, for example, a phenol novolak resin, a cresol novolak resin, a phenol aralkyl resin, and a terpene skeleton-containing Phenolic resins, trishydroxyphenylmethane, naphthol derivatives, naphthalene diol derivatives, various novolak resins synthesized from bisphenol A and resorcinol, resole resins, various polyhydric phenol compounds such as polyvinylphenol, maleic anhydride, phthalic anhydride, and pyroanhydride Examples thereof include acid anhydrides and organic acids such as melitic acid, and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Among them, phenol compounds having two or more hydroxyl groups in one molecule are preferable from the viewpoint of adhesion, and phenol novolak resin, trishydroxymethane, phenol having a terpene skeleton, etc. are particularly preferable.

In the present invention, the mixing ratio of the epoxy resin (A) and the curing agent (B) is not particularly limited, but from the viewpoint of the mechanical properties and adhesion of the cured product of the obtained epoxy resin and the semiconductor device. It is preferable that the chemical equivalent ratio of (B) to (A) is in the range of 0.5 to 1.5, particularly 0.8 to 1.2.

In the present invention, the epoxy resin (A)
A curing catalyst for accelerating the curing reaction between the curing agent (B) and the curing agent (B) may be used. The curing catalyst is not particularly limited as long as it promotes the curing reaction. For example, 2-methylimidazole,
Imidazole compounds such as 2,4-dimethylimidazole, 2-methyl-4-methylimidazole, 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine,
(Dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0) undecene-7,1,5-
Tertiary amine compounds such as diazabicyclo (4,3,0) nonene-5; organometallic compounds such as zirconium tetramethoxide, zirconium tetrapropoxide, tetrakis (acetylacetonato) zirconium, and tri (acetylacetonato) aluminum; Phenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine,
Organic phosphine compounds such as triphenylphosphine / triphenylborane and tetraphenylphosphonium / tetraphenylborate are exemplified. Among them, triphenylphosphine, tetraphenylphosphonium tetraphenylborate and 1,8-diazabicyclo (5,4,0) undecene-7 are particularly preferably used from the viewpoint of reactivity. Two or more of these curing catalysts may be used in combination depending on the application, and the addition amount thereof is preferably in the range of 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy resin (A).

In the epoxy resin composition of the present invention, a filler (C) is blended, and amorphous silica, crystalline silica,
Calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, antimony oxide, asbestos, glass fiber, etc., among which amorphous silica has a large effect of lowering the linear expansion coefficient, It is preferably used because it is effective for lowering the stress. Examples of the amorphous silica include fused silica produced by melting quartz and synthetic silica produced by various synthetic methods, and crushed or spherical ones are used.

In the present invention, the blending amount of the filler (C) is not particularly limited, but the flexural modulus at 23 ° C. of the cured product of the epoxy resin composition of the present invention is 30 GPa or less, and the glass transition temperature from 23 ° C. 4 × linear expansion coefficient
In order to be 10 ^{-6 to} 20 × 10 ^-6 / K, usually 75 to 97% by weight of the whole epoxy resin composition, and further 80 to 95%
% By weight.

In the epoxy resin composition of the present invention,
Coupling agents such as a silane coupling agent and a titanate coupling agent can be blended. Among them, it is preferable from the standpoint of reliability that the filler be surface-treated with these coupling agents in advance. As the silane coupling agent, a silane coupling agent in which a hydrocarbon group having a functional group such as an alkoxy group, an epoxy group, an amino group, or a mercapto group bonded to a silicon atom is preferably used. Among them, it is particularly preferable to use a silane coupling agent having an amino group from the viewpoint of fluidity.

The epoxy resin composition of the present invention contains a halogen compound such as a halogenated epoxy resin, a flame retardant such as a phosphorus compound, a flame retardant auxiliary such as antimony trioxide, a colorant such as carbon black and iron oxide, a long chain. Release agents such as fatty acids, metal salts of long-chain fatty acids, esters of long-chain fatty acids, amides of long-chain fatty acids, paraffin wax, and low-stressing agents such as elastomers and rubbers, and crosslinking agents such as organic peroxides. Can be added.

The epoxy resin composition of the present invention is preferably obtained by melting and kneading these raw materials. For example, a known kneading method such as a Banbury mixer, a kneader, a roll, a single or twin screw extruder and a co-kneader may be used. It is manufactured by melt-kneading. Then, a semiconductor device is obtained by molding using a pellet or a powdery epoxy resin in a mold in which a semiconductor device spare device in which the semiconductor element 1 is mounted on the substrate 2 is arranged. In particular, the epoxy resin composition of the present invention is advantageous for a semiconductor device having no structure substantially surrounding the epoxy resin composition.

[0027]

The present invention will be described below in detail with reference to examples.

Examples 1 to 5 and Comparative Examples 1 to 5 The components shown in Table 1 were dry-blended by a mixer at the composition ratios shown in Tables 2 and 3. This was heated and kneaded for 5 minutes using a mixing roll having a roll surface temperature of 90 ° C.
The mixture was cooled and pulverized to produce an epoxy resin composition.

[0029]

[Table 1] Using this composition, a low pressure transfer molding method was used, at a molding temperature of 175 ° C., a molding time of 2 minutes, and a transfer pressure of 7
The composition was molded under the conditions of MPa and post-cured under the conditions of 180 ° C. × 5 hours, and the flexural modulus and the coefficient of linear expansion of each composition were measured.

Linear expansion coefficient: The average value was determined from the thermal expansion curve between 23 ° C. and the glass transition temperature using TMA.

As for the glass transition temperature, a thermal expansion curve was drawn using TMA, and a broken line at 57 ° C. and 250 ° C. was drawn, and the temperature at the intersection was defined.

Flexural modulus: A three-point bending test was performed at 23 ° C., and determined from a load-deflection curve.

Using this composition, a semiconductor device spare device having the shape shown in FIG. 3 was provided in a mold, and subjected to transfer molding and post-cure under the same conditions as described above.
A simulated semiconductor device as shown in FIG. The physical properties of each composition and semiconductor device were measured by the following physical property measurement methods.
The simulated semiconductor device shown in FIG. 2 includes a semiconductor element 1, a substrate 2 on which the semiconductor element is mounted, and an epoxy resin composition 3 for encapsulating the semiconductor element using this composition. Is formed by

The dimensions of each part of the semiconductor device shown in FIG. 2 are as follows.

Semiconductor element 1: 7 × 7 × 0.5 mm Adhesive layer 4 thickness: 0.1 mm Epoxy resin 3: 8 × 8 × 1.0 mm Substrate base material thickness: 0.1 mm Package warpage amount: Simulated semiconductor device flat surface The surface unevenness was measured on the diagonal line using a surface roughness meter, and the distance between the lowest point and the highest point when viewed from the horizontal direction was measured in the vertical direction. If the amount of warpage is 100 μm or more, the mountability of the printed circuit board deteriorates, and the defective mounting rate deteriorates.

Thermal cyclability: Simulated semiconductor device
65 ° C × 30min, room temperature × 10min, 150 ° C × 3
A leaving test was performed using 20 semiconductor devices with 0 min, normal temperature × 10 min as one cycle. After 100 cycles have elapsed, the four semiconductor devices are disassembled and the inside is visually observed, cracks in the resin portion and cracks in the semiconductor element are determined as failures, and the number of cycles when the failure rate exceeds 50% Was observed.

The following characteristics were evaluated.

Spiral flow: Measured under the above molding conditions at a molding speed of 25 m / sec using an EMMI mold evaluation mold. Usually, if it is not more than 50 cm, the molded product is not filled.

Thermal hardness: The surface of the molded product after a molding time of 180 seconds under the above molding conditions was measured using a Barber-Coleman hardness tester. If the hardness at the time of heating is not 70 or more, mold stains and the like occur, which causes a problem in continuous productivity.

The results are shown in Tables 2 and 3.

[0041]

[Table 2]

[Table 3] As seen from Tables 2 and 3, the epoxy resin composition and the resin-encapsulated semiconductor device of the present invention are excellent in reduction of package warpage and thermal cyclability.

Comparative Example 1 having a small coefficient of linear expansion and a small warpage but a large elastic modulus is inferior in thermal cycling. In the comparative example having a low glass transition temperature, the warpage is worse. Also, in Comparative Example 3 in which the product of the coefficient of linear expansion and the elastic modulus is large, the warpage is also deteriorated. In Comparative Example 4 in which the elastic modulus was kept low, the hardness at the time of heating was insufficient, and there was a problem in continuous productivity.

[0043]

The resin composition of the present invention and the semiconductor device filled with the resin composition are excellent in reducing the amount of warpage, and the semiconductor device using the resin composition is excellent in thermal cyclability.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a semiconductor device of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating one embodiment of a semiconductor device of the present invention.

FIG. 3 is a schematic cross-sectional view of a semiconductor device spare device used in an embodiment of the present invention.

[Explanation of symbols]

 1: Semiconductor element 2: Substrate 2a: Substrate base material 2b: Conductive part 2c: Metal wiring 3: Epoxy resin composition 4: Adhesive layer 5: Lead wire 6: Solder ball

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BC12X CC04X CC05X CC06X CD01W CD02W CD04W CD05W CD06W CD12W CE00X DE077 DE097 DE137 DE147 DE237 DJ007 DJ017 DJ027 DJ047 DL007 EF006 EJ016 EJ046 EL136 EL146 EN036 EN076 EV216 FA047 FB006 FD146 FD160 GQ05 HA09 4M109 AA01 BA03 CA21 DA10 EA03 EB03 EB04 EB06 EB07 EB08 EB09 EB13 EB17 EB19 EC03

Claims (6)

[Claims] 1. A semiconductor device comprising a semiconductor element, a substrate on which the semiconductor element is mounted, and a cured product of an epoxy resin composition for encapsulating the semiconductor element, wherein the semiconductor device is provided on one surface with respect to the substrate. Only the epoxy resin composition is molded, and the epoxy resin composition is an epoxy resin (A),
The epoxy resin composition contains a curing agent (B) and an inorganic filler (C), and the cured product of the epoxy resin composition has a flexural modulus at 23 ° C. of 10
GPa, 30 GPa or less, and a coefficient of linear expansion from 23 ° C. to a glass transition temperature of 4 × 10 ^{−6 to} 20 × 10 ⁻⁶ /
K, the product of the flexural modulus at 23 ° C. and the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 3 × 10 ⁻⁴ GPa / K or less, and the glass of the cured product of the epoxy resin composition A resin-sealed semiconductor device having a transition temperature of 150 ° C. or higher. 2. The cured product of the epoxy resin composition has a coefficient of linear expansion from 23 ° C. to a glass transition temperature of 4 × 10 ^{-6 to} 16
2. The resin-encapsulated semiconductor device according to claim 1, wherein the value is × 10 ⁻⁶ / K. 3. The cured product of the epoxy resin composition has a coefficient of linear expansion from 23 ° C. to a glass transition temperature of 8 × 10 ^{-6 to} 16
× 10 ^-6 / K, a resin-sealed semiconductor device according to claim 1, wherein the glass transition temperature, characterized in that at 170 ° C. or higher. 4. A semiconductor device sealing device comprising: a semiconductor element, a substrate on which the semiconductor element is mounted, and an epoxy resin composition, wherein the epoxy resin composition is molded on only one surface of the substrate. An epoxy resin composition, wherein the epoxy resin composition contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C), and a cured product of the epoxy resin composition at 23 ° C. Flexural modulus exceeding 10 GPa, 30
GPa or less, the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 4 × 10 ^{−6 to} 20 × 10 ⁻⁶ / K, the flexural modulus at 23 ° C., and the coefficient of linear expansion from 23 ° C. to the glass transition temperature. Is 3 × 10 ⁻⁴ GPa / K or less, and the glass transition temperature of the cured product of the epoxy resin composition is 150
An epoxy resin composition for encapsulating a resin-encapsulated semiconductor device, wherein the temperature is not less than ° C. 5. The cured product of the epoxy resin composition has a coefficient of linear expansion from 23 ° C. to a glass transition temperature of 4 × 10 ^{−6 to} 16 ×.
The epoxy resin composition according to claim 4, wherein the epoxy resin composition is 10 ^-6 / K. 6. The cured product of the epoxy resin composition has a coefficient of linear expansion from 23 ° C. to a glass transition temperature of 8 × 10 ^{−6 to} 16 ×.
The epoxy resin composition for sealing a resin-sealed semiconductor device according to claim 4, wherein the epoxy resin composition has a glass transition temperature of ^10-6 / K or more.