JPH10265546A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition excellent in adhesion properties and reliability and provide a semiconductor-device sealed with the epoxy resin composition by bringing the device smaller and to have higher performance. SOLUTION: This semiconductor-device is installed with a semiconductor element 1, a substrate 2 on which the semiconductor element 1 is mounted and an epoxy resin composition 3 for sealing the semiconductor element and the epoxy resin composition is formed solely on one side of the substrate. The epoxy resin composition contains an epoxy resin, a curing agent and an inorganic filler. The flexural modulus of elasticity of a cured resin composition is >10 GPa and <=30 GPa, the coefficient of linear expansion from 23 deg.C to the glass transition temperature is 4-10×10<-6> /K and (flexural modulus of elasticity at 23 deg.C)×(coefficient of linear expansion from 23 deg.C to the glass transition temperature)<=2×10<-4> GPa/K.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-sealed semiconductor device, and more 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 more particularly, to the sealing resin. The present invention relates to a semiconductor 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. A thin TSOP (Thin Small Outline Package) with a small volume of the sealing resin and a QFP (Quad Flat Package) compatible with a large number of pins have been developed.

Further, in order to reduce the mounting area occupied by the semiconductor device and improve the 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. With this structure,
Since the sealing resin is molded on only 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, if peeling occurs at the bonding interface with the substrate or the semiconductor element, it causes a failure in the thermal cycle test and the popcorn resistance test.

[0004]

Accordingly, there is a need to provide a sealing resin which is compatible with semiconductor devices having a different form from that of the prior art and which is excellent in reducing the amount of warpage of the semiconductor device.

That is, an object of the present invention is to provide a semiconductor device having a structure in which a sealing resin is molded on only one side of a substrate, and have excellent adhesiveness, a reduced amount of warpage of the semiconductor device, excellent thermal cycling properties, and excellent popcorn resistance. Epoxy resin composition,
And a semiconductor device sealed with the epoxy resin composition.

[0006]

Means for Solving the Problems The present inventors have developed a semiconductor device having a structure in which a sealing resin is molded on only one side of a substrate. The present inventors have conducted intensive studies for the purpose of improving popcorn properties, and have reached the present invention. That is, the present invention provides a semiconductor device comprising a semiconductor element 1, a substrate 2 on which the semiconductor element is mounted, and a cured product 3 of an epoxy resin composition for sealing the semiconductor element. On the other hand, the epoxy resin composition is molded only on one side, and a cured product of the epoxy resin composition contains an epoxy resin (A), a curing agent (B), and an inorganic filler (C). A resin-encapsulated semiconductor device in which the cured product of the epoxy resin composition has the following characteristics (a) to (c): (a) The flexural modulus at 23 ° C exceeds 10 GPa,
GPa or less (b) Coefficient of linear expansion from 23 ° C to glass transition temperature is 4 ×
10 ^-6 to 10 × 10 ^-6 / K (c) (Bending elastic modulus at 23 ° C.) × (linear expansion coefficient from 23 ° C. to glass transition temperature) is 2 × 10 ⁻⁴ GPa / K or less ”and“ A semiconductor device comprising a semiconductor element 1, a substrate 2 on which the semiconductor element is mounted, and an epoxy resin composition 3, wherein the epoxy resin composition is molded on only one side of the substrate. An epoxy resin composition for stopping, wherein the cured product of the epoxy resin composition comprises an epoxy resin (A), a curing agent (B), and an inorganic filler (C). The cured product is the following (A) ~
An epoxy resin composition for encapsulating a resin-encapsulated semiconductor device having the characteristic of (c). (B) The flexural modulus at 23 ° C. exceeds 10 GPa and
GPa or less (b) Coefficient of linear expansion from 23 ° C to glass transition temperature is 4 ×
10 ⁻⁶ to 10 × 10 ⁻⁶ / K (c) (Bending elastic modulus at 23 ° C.) × (linear expansion coefficient from 23 ° C. to the glass transition temperature) is 2 × 10 ⁻⁴ GPa / K or less. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below 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 a powder or a tablet. And the epoxy resin composition is, for example, 120 to
It is manufactured by molding at a temperature of 250 ° C., preferably 150 to 200 ° C., by a method such as transfer molding, injection molding, and casting method. If necessary, additional heat treatment (for example, 150 to 180 ° C.,
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 and an insulating material are used. Preferably, there is.
As such a material, a synthetic resin and further a polyimide are preferable. In addition, since the internal stress of the semiconductor device is reduced, the substrate is preferably made of a flexible material.

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 GPa.
a, the coefficient of linear expansion from 23 ° C. to the glass transition temperature is 4 × 10 ⁻⁶ to 10 × 10 ⁻⁶ / K, and (23 ° C.
Flexural modulus) × (linear expansion coefficient from 23 ° C. to the glass transition temperature) 2 × 10 ⁻⁴ GPa / K or less. Only when the physical properties in this range are satisfied, a semiconductor device having good adhesion, small internal stress of the semiconductor device, and high reliability can be obtained. When the coefficient of linear expansion in the glassy region is large, the amount of warpage of the semiconductor device is large, and the thermal cycling property and popcorn resistance are poor. If the coefficient of linear expansion is small, peeling is likely to occur at the interface between the resin and the substrate, resulting in poor thermal cycling properties. When the flexural modulus is large, the adhesion between the sealing resin and the substrate or semiconductor element is reduced. When the flexural modulus is low, workability is poor. Also,
Even if the cured product of the epoxy resin composition has a flexural modulus at 23 ° C. of ≦ 30 GPa and a coefficient of linear expansion from 23 ° C. to the glass transition temperature of 4 to 10 × 10 ⁻⁶ / K, (23 ° C. When the flexural modulus) × (linear expansion coefficient from 23 ° C. to the glass transition temperature) exceeds 2 × 10 ⁻⁴ GPa / K, the amount of warpage of the semiconductor device is large, and the adhesion is reduced.

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

The epoxy resin composition of the present invention comprises:
Epoxy resin (A) is usually 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, resorcinol, etc., linear aliphatic epoxy resin, fatty acid A cyclic epoxy resin, a heterocyclic epoxy resin, a halogenated epoxy resin and the like can be mentioned.

Depending on the application, two or more epoxy resins may be used in combination. However, from the viewpoint of heat resistance and moisture resistance, it is preferable that the pre-epoxy resin contains at least 50% of a biphenyl type epoxy resin. The content of the epoxy resin in the epoxy resin composition of the present invention is 2 to 15% by weight, more preferably 2 to 15% by weight.
12% by weight is preferred.

The curing agent (B) is usually added to the epoxy resin composition of the present invention. Such a resin is not particularly limited as long as it reacts with the epoxy resin (A) and is cured. Specific examples thereof include a phenol novolak resin, a cresol novolak resin, a phenol aralkyl resin, and a terpene skeleton-containing resin. Various novolak resins synthesized from phenolic resins, trishydroxyphenylmethane, bisphenol A and resorcinol,
Various polyhydric phenol compounds such as resole resin and polyvinyl phenol, acid anhydrides such as maleic anhydride, phthalic anhydride, and pyromellitic anhydride, and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, etc. can give. Among them, a phenol compound having two or more hydroxyl groups in one molecule is preferable from the viewpoint of adhesion, and a phenol novolak resin and a phenol aralkyl resin are particularly preferable.

In the present invention, the mixing ratio of the epoxy resin (A) and the curing agent (B) is not particularly limited. However, from the viewpoint of the mechanical properties and adhesion of the cured product of the 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. The content of the curing agent in the epoxy resin composition of the present invention is preferably 2 to 15% by weight, more preferably 2 to 12% by weight.

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 generally blended, and amorphous silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, oxide Titanium, antimony oxide, asbestos, and glass fiber are also preferable. Among them, amorphous silica is preferably used because it has a large effect of lowering the coefficient of linear expansion and is effective in reducing 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 cured product of the present invention has a flexural modulus at room temperature of 30 GPa or less and a linear expansion coefficient from room temperature to the glass transition temperature of 4%. × to be ^{10 -6 ~10 × 10 -6 / K} , 80~95 wt% of the total epoxy resin composition,
Further, the content is preferably 85 to 93% 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 silane coupling agents, alkoxy groups and "epoxy groups, amino groups,
A silane coupling agent having a "hydrocarbon group having a functional group such as 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 can contain an elastomer (D), which has the effect of reducing the warpage of the semiconductor device and reducing the stress. Such materials include, for example, silicone rubber, EPR, EPDM, S
Examples include olefin copolymers such as EBS, nitrile rubber, polybutadiene rubber, and modified silicone oil. In addition to the elastomer (D), a thermoplastic resin such as polyethylene can be blended as a stress reducing agent. Flexural modulus at room temperature of the cured product of the present invention is 30G
In order to make it Pa or less, it is preferable to use these elastomers and stress reducing agents.

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. A releasing agent such as a fatty acid, a metal salt of a long-chain fatty acid, an ester of a long-chain fatty acid, an amide of a long-chain fatty acid, paraffin wax and a crosslinking agent such as an organic peroxide can be optionally 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.

[0025]

The present invention will be described below in detail with reference to examples. The values in Table 2 indicate parts by weight.

Examples 1 to 5 and Comparative Examples 1 to 4 The components shown in Tables 1 and 2 were dry-blended by a mixer at the composition ratios shown in Table 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.

[0027]

[Table 1]

Embedded image (N is an integer of 0 or more.)

[0028]

[Table 2]

This composition was molded by a low pressure transfer molding method under the conditions of a molding temperature of 175 ° C., a molding time of 2 minutes, and a transfer pressure of 7 MPa, and was post-cured at 180 ° C. for 5 hours. The flexural modulus and the coefficient of linear expansion were measured. The coefficient of linear expansion uses TMA.
The average value was determined from the thermal expansion curve between 3 ° C. and the glass transition temperature. The flexural modulus performs a three-point bending test at room temperature.
It was determined from a load-deflection curve. Table 3 shows the results.

Using the composition, a semiconductor device spare device having the shape shown in FIG. 3 is provided in a mold, and transfer molding and post-curing are performed under the same conditions as described above to assemble a simulated semiconductor device as shown in FIG. Was. 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: 20 × 20 × 1.0 mm Metal wiring 2c thickness: 0.1 mm Substrate base material thickness: 0.15 mm PI film Peel strength: A square pillar having a length of 10 × 10 mm and a height of 5 mm was formed on a PI film by the above-mentioned forming method, and the peel strength was measured by a 180 ° peel test. This value reflects the adhesion between the substrate and the sealing resin.

Package warpage: The surface roughness is measured using a surface roughness meter on the diagonal line of the simulated semiconductor device plane, and the distance between the lowest point and the highest point when viewed from the horizontal direction is determined in the vertical direction. Was measured.

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. 100 cyc
After leaving for a while, the semiconductor device was disassembled and the inside was visually observed. Cracking of the resin portion and cracking of the semiconductor element were determined as failures, and the failure rate was determined.

Popcorn test: 20 simulated semiconductor devices were humidified at 85 ° C./85% RH for 48 hours, and then a maximum temperature of 24
Heat treatment in a 5 ° C. IR reflow furnace,
The presence or absence of peeling at the interface between the film substrate and the resin was visually observed. As the failure rate, the ratio of the packages where peeling occurred was obtained.

Table 3 shows the results.

[0037]

[Table 3]

As can be seen from Table 3, the epoxy resin composition of the present invention and the resin-encapsulated semiconductor device exhibited excellent adhesion,
Excellent package warpage, thermal cycling and popcorn resistance. On the other hand, Comparative Example 1 having a flexural modulus of 11.2 GPa instead of 30 GPa or less according to the present invention has a small package warpage, but is inferior in other physical properties. Comparative Example 2 having a coefficient of linear expansion of 11 × 10 ⁻⁶ / K, which is not in the range of the present invention, is excellent in adhesion, but inferior in package warpage, popcorn resistance, and thermal cycling. The coefficient of linear expansion is 3 × 1
Comparative Example 3 of 0 ^-6 / K has a small amount of package warpage and good thermal cyclability, but is inferior in adhesion and popcorn resistance. (Flexural modulus) × (linear expansion coefficient) is 2.
Comparative Example 4 of 05 × 10 ⁻⁴ GPa / K is inferior in all physical properties.

[0039]

According to the resin composition of the present invention, the adhesion is excellent and the amount of warpage of the semiconductor device is reduced, and the semiconductor device using the resin composition is excellent in thermal cycling and popcorn resistance.

[Brief description of the drawings]

FIG. 1 is a schematic view (cross section) illustrating one embodiment of a semiconductor device of the present invention.

FIG. 2 is a schematic view (cross section) illustrating one embodiment of a semiconductor device of the present invention.

FIG. 3 is a schematic view (cross section) 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: Conducting part 2c: Metal wiring 3: Epoxy resin composition 4: Adhesive layer 5: Lead wire 6: Solder ball

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/29 H01L 23/30 R 23/31

Claims (4)

[Claims] 1. A semiconductor device comprising a semiconductor element 1, a substrate 2 on which the semiconductor element is mounted, and a cured product 3 of an epoxy resin composition for encapsulating the semiconductor element. The epoxy resin composition is molded only on one side, and the cured product of the epoxy resin composition comprises an epoxy resin (A), a curing agent (B), and an inorganic filler (C). A resin-encapsulated semiconductor device, wherein a cured product of the resin composition has the following characteristics (a) to (c). (B) The flexural modulus at 23 ° C. exceeds 10 GPa and
GPa or less (b) Coefficient of linear expansion from 23 ° C to glass transition temperature is 4 ×
10 ⁻⁶ to 10 × 10 ⁻⁶ / K (c) (Bending elastic modulus at 23 ° C.) × (linear expansion coefficient from 23 ° C. to glass transition temperature) is 2 × 10 ⁻⁴ GPa / K or less 2. A semiconductor device comprising: a semiconductor element 1; a substrate 2 on which the semiconductor element is mounted; and an epoxy resin composition 3. The epoxy resin composition is molded on only one surface of the substrate. An epoxy resin composition for encapsulating a semiconductor device, wherein the cured product of the epoxy resin composition comprises an epoxy resin (A), a curing agent (B), and an inorganic filler (C). The cured product of the epoxy resin composition is the following (A) ~
An epoxy resin composition for encapsulating a resin-encapsulated semiconductor device having the characteristic of (c). (B) The flexural modulus at 23 ° C. exceeds 10 GPa and
GPa or less (b) Coefficient of linear expansion from 23 ° C to glass transition temperature is 4 ×
10 ⁻⁶ to 10 × 10 ⁻⁶ / K (c) (Bending elastic modulus at 23 ° C.) × (linear expansion coefficient from 23 ° C. to glass transition temperature) is 2 × 10 ⁻⁴ GPa / K or less 3. The resin-sealed semiconductor device according to claim 1, wherein said epoxy resin composition comprises an elastomer (D). 4. The epoxy resin composition for semiconductor encapsulation according to claim 2, wherein said epoxy resin composition comprises an elastomer (D).