JPH04256345A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a semiconductor device which is excellent in a thermal shock-resistant property and whose reliability is excellent even for its high level of integration or for its small and thin shape. CONSTITUTION:A molding material, for sealing use, which is composed of the following is used: an epoxy resin which has two or more epoxy groups in a molecule; an organic polymer which has been coated with an inorganic sol; and an inorganic filler. Since the molding material, for sealing use, which uses the organic polymer coated with the inorganic sol is excellent in a function to relax an internal stress, it is possible to easily obtain a semiconductor device as a target.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a semiconductor device that has excellent reliability even if it is highly integrated or small and thin, and is used in various industries including the electronic industry. be.

0002

[Prior Art] Various efforts have been made to reduce the stress of epoxy resins used as molding materials for semiconductor encapsulation.
Among these, the main methods include adding an organic polymer with a low elastic modulus, especially a rubbery substance, or adding an inorganic material with a low coefficient of thermal expansion, especially a fused silica powder.

0003

[Problems to be Solved by the Invention] However, it is difficult to uniformly disperse a rubbery material, especially a high molecular weight elastomeric polymer with high heat resistance, in a molding material, and if a large amount of fused silica powder is mixed. Although the coefficient of thermal expansion decreases, the moldability significantly decreases and a limit can be seen.

0004

[Means for Solving the Problems] The present invention provides that (1) a coating using an inorganic sol is applied to 100 parts by weight of an epoxy resin containing two or more epoxy groups in one molecule (hereinafter abbreviated as epoxy resin); A molding material containing 1 to 100 parts by weight of the applied organic polymer (which can also be called a capsule body containing the organic polymer and hereinafter abbreviated as the capsule body) and (2) 100 to 800 parts by weight of an inorganic filler. It is an object of the present invention to provide a semiconductor device characterized in that it is sealed by.

The technical elements to be emphasized in the present invention are as follows.

○ The epoxy resin contained as a resin component in the epoxy resin molding material is 1
As long as the molecule contains two or more epoxy groups, there are no particular limitations, and conventional methods such as cresol novolak type, phenol novolak type, or bisphenol A type, etc.
Various epoxy resins used as molding materials for sealing semiconductor devices can be used, but those having a melting point of room temperature or higher are preferred.

[0007] In the case of noporac type, the epoxy equivalent is 160
~250°C and a softening point of 50~130°C are preferred.

[0008] As curing agents for epoxy resins, acid anhydrides,
Known curing agents such as phenols and polyamides can be used, but phenol or cresol novolak resins having a hydroxyl equivalent of 70 to 150 are preferred. Furthermore, examples of the curing accelerator include 2,4,6-tridimethylaminomethylphenol, 2-methylimidazole, 2-undecylimidazole, triphenylphosphine, and triphenylphosphine tetraphenylborate.

Capsule body The capsule body used in the present invention is a capsule body containing an organic polymer coated with an inorganic sol, and has a structure and properties different from that of ordinary organic polymer fine powder. It is something. For example, it does not show stickiness even under high temperatures,
Furthermore, even during organic melting, it is difficult to swell and can maintain a single fine particle morphology. Therefore, this capsule body can easily maintain a single fine particle morphology in various epoxy resins and take a so-called "sea-island structure", so it exhibits a high degree of thermal stress absorption or relaxation effect. do. Furthermore, since this capsule body is coated with an inorganic material, it has essentially excellent heat resistance. Further, when the particle size is 0.5 to 50 μm, the internal stress relaxation function is enhanced and the moldability of the molding material is also good, so it is preferable.

[0010] The above-mentioned effects have a great function of alleviating internal stress when a polymer having a particularly low Tg or a rubber-like polymer is used as the encapsulated organic polymer. The amount of the capsule to be used is 1 to 100 parts by weight per 100 parts by weight of the epoxy resin. If the amount is less than 1 part by weight, the relaxation function will not be exhibited, and if it exceeds 100 parts by weight, the moldability of the molding material will be poor, which is inappropriate.

○Production method of capsule body An organic polymer is coated with an inorganic substance using an inorganic sol.
That is, as the encapsulation method referred to in the present invention, the powder bed method, electrostatic pulverization method, composite emulsion method, etc. are known, and capsule bodies obtained by these methods can also be used in the present invention, but the following The synthesis method is particularly industrially advantageous,
Suitably used in the present invention.

That is, an organic polymer emulsion with silanol groups bonded to its surface is synthesized, an inorganic sol is adsorbed onto this emulsion, the resulting emulsion mixture is made into a slurry in an organic polymer aqueous solution, and then dehydrated to form a fine powder. This is a method for obtaining powdered capsules.

The inorganic material on which the film is formed in this manner is derived from a sol of silica, alumina, titanium oxide, iron oxide, antimony oxide, metal oxide, or metal oxide such as zirconia, and is ~50% by weight
It is preferred for the present invention that it be included.

On the other hand, as for the organic polymer to be included, the following organic polymer emulsion having silanol groups on the surface can be synthesized by a core-shell type emulsion polymerization method.

That is, an emulsion containing an organic polymer emulsion as a core, such as a polyolefin, a polydiene, an unsaturated aliphatic ester polymer, a fatty acid vinyl polymer, or a copolymer having these as the main component, is synthesized in advance. do. Next, in the presence of the organic emulsion, acrylonitrile, methacrylonitrile, N-vinylpyrrolidone,
Or N-vinylcaprolactam and acryloxy group,
This is a core-shell emulsion obtained by copolymerizing monomers containing alkoxysilanes having methacryloxy groups or vinyl groups. In addition, acryloxy group,
Specific examples of alkoxysilanes having a methacryloxy group or a vinyl group include γ-acryloxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltris(trimethylsiloxy)silane, vinyl Examples include trimethoxysilane, vinyltriethoxysilane, vinyltris(methoxyethoxy)silane, and vinyltrichlorosilane.

[0016] Inorganic filler Various conventionally known inorganic materials in the form of fine powder with a particle size of 0.1 to 150μ can be used, including fused silica, silica powder, talc, etc., which do not impede electrical insulation properties. Alumina, calcium carbonate, etc. are preferred.

The amount used should be 100 to 800 parts by weight per 100 parts by weight of the epoxy resin.

If the amount is less than 100 parts by weight, the stress relieving function will not be sufficient, and if it exceeds 800 parts by weight, the melt viscosity of the molding material will increase during molding, impeding the moldability, so each is unsuitable. .

Other compounding agents for forming the molding material Silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, or tetraoctyl bis(phosphorus Carvana wax, stearic acid and its metal salts, montanic acid or ester wax, etc. can be used as a mold release agent using a titanium-based coupling agent such as phyto) titanate.
In order to improve flame retardancy, carbon black can be blended with a phosphazene compound, a brominated epoxy resin, or antimony trioxide as a pigment.

Molding method A composition containing an epoxy resin, a capsule and an inorganic filler is mixed and kneaded, and then pulverized. Next, a semiconductor device is completed by sealing required sealing portions using the composition by transfer molding or the like.

○Usage Method The semiconductor device of the present invention is used for forming ultra-high density integrated circuits, which are required in response to increasing element size and miniaturizing or thinning packages.

[0022]

[Action] By using such a composition with an appropriate composition ratio of epoxy resin, capsule body, and inorganic filler as a molding material for encapsulating semiconductor devices, it has heat resistance and thermal shock resistance. , imparts a large internal stress relaxation function.

[0023]

[Examples] The present invention will be further explained in detail by referring to examples of the present invention and comparative examples thereof, but the present invention is not limited to these examples.

Examples 1 to 6, Comparative Examples 1 to 2 Synthesis of Capsules Capsules containing styrene-butadiene rubber coated with silica were synthesized by the following method. In a 2L four-necked flask, 310cc of pure water, 1220gr of styrene-butadiene rubber emulsion "Truck Super" (solid content 45.0% by weight, manufactured by Nippon Latex Kako Co., Ltd.), 98gr styrene, 42gr acrylonitrile, γ-methacryloxypropyl tritrile. 8g of methoxysilane and 0.8g of ammonium persulfate were purchased, and while nitrogen was flowing into the space, the temperature was kept at 70°C while stirring with a propeller-type stirring blade (350rpm).
m) Emulsion polymerization was performed for 4 hours.

[0025] 720g of the obtained emulsion (solid content 40.5% by weight) was mixed with silica sol "Snowtex UP".
(Solid content 20% by weight, thickness 5-20mμ, length 40-3
00mμ rod-shaped colloidal silica and 160gr manufactured by Nissan Chemical Industries, Ltd. were mixed to make "Metrose 90SH40
00'' (hydroxyprocel methyl cellulose, high viscosity type, manufactured by Shin-Etsu Chemical Co., Ltd.) was placed in a 12 L mixing tank containing 3700 cc of a 0.5% by weight aqueous solution at 25°C under stirring with a propeller type stirring blade (600 rpm). was added over 20 minutes to form a slurry.

The obtained slurry was repeatedly filtered and washed with water until the solid content was 9% by weight and the pH was 5.5, and then passed through a disk-type spray dryer to remove 90% by weight of a butadiene copolymer with a particle size of 1 to 10 μm. 290 gr of finely powdered capsule bodies having a film containing 10% by weight of silica were obtained.

Preparation of the molding material composition for sealing 100 parts by weight of an epoxy resin with an epoxy equivalent of 190 and a softening point of 80°C. 50 parts by weight of a phenol novolac resin with a phenol equivalent of 130 and a softening point of 80°C as a curing agent, and a curing accelerator. 0.5 parts by weight of 2-methylimidazole, 0.5 parts by weight of stearic acid as a lubricant, and particle size 3 to 12 as an inorganic filler.
After blending 0 μm spherical fused silica and the capsules obtained in this example as shown in Table 1, they were mixed in a mixer, and further
After melt-mixing for 3 minutes using a heated roll at 90°C, the mixture was cooled and pulverized.

○Sealing of integrated circuit components Using the above composition, an 18-pin DIP (package width 8.88 mm, element occupation area ratio 60%) was sealed by transfer molding (175° C., 30 kg/cm2, 3 minutes). did. This was further post-cured at 175° C. for 4 hours.

○ Thermal Shock Test The number of cracks generated after 10 cycles of maintaining the above prototype integrated circuit components at 280°C for 2 minutes and -196°C for 2 minutes was as shown in Table 1. .

[0030]

[Table 1]

Examples 7 to 12, Comparative Examples 3 to 4 ○ In the synthesis example of the capsule body, 70% by weight of butyl acrylate and 29.8% by weight of 2-ethoxyethyl acrylate were used instead of "Tomac Super". % and allyl methacrylate 0.2% by weight (solid content 45.0% by weight). .3% by weight, neutral water dispersion, 246gr (manufactured by Nissan Chemical Industries, Ltd.) was synthesized under the same conditions as above, and as a result, 90% by weight of an acrylic copolymer with a particle size of 2 to 15 μm was synthesized. 300 gr of fine powder was obtained which was used as a core material and had a film containing 10% by weight of antimony oxide.

[0032] In the preparation of the composition to which the molding material composition for sealing is prepared (instead of spherical fused silica, particles with a particle size of 0.5 to
Using 80 μm prismatic fused silica and the capsule obtained in this example, the other ingredients were similarly blended as shown in Table 2, and then evaluated in the same manner as in the previous example. Became.

[0033]

[Table 2]

[0034]

[Effects of the Invention] As explained in the Examples and Comparative Examples, the semiconductor device of the present invention has excellent thermal shock resistance because the molding material for sealing used therein exhibits a remarkable internal stress relaxation function. Even if the device has a high degree of integration or is small and thin, it has excellent reliability, and it can be seen that the present invention is industrially useful.

Claims (1)

[Claims] Claim 1: 1 to 100 parts by weight of an organic polymer coated with an inorganic sol and 100 to 800 parts by weight of an inorganic filler per 100 parts by weight of an epoxy resin containing two or more epoxy groups in one molecule. 1. A semiconductor device characterized in that the semiconductor device is sealed with a molding material containing a portion.