JPH0689948A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a semiconductor device sealed with a resin with low-stress and excellent heat resistance, especially, an optical semiconductor sealed with a transparent resin having low-stress and excellent heat resistance. CONSTITUTION:This device is manufactured by sealing a semiconductor element with a resin composition composed of a thermosetting resin, curing agent, <=5X10<-5>mol/g of a hydroxyl group, and silica particles having particle sizes of <=0.1mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device resin-sealed with a sealing resin having excellent heat resistance and low stress, and particularly to an optical semiconductor device resin-sealed with a transparent sealing resin. It is about.

[0002]

2. Description of the Related Art At present, many optical semiconductor devices are sealed with transparent epoxy resin, but there is a problem that the element is deteriorated by the internal stress of the resin cured body. For example, in the case of an LED (light emitting diode), the brightness decreases. Therefore, the present inventors have found that in order to obtain a transparent and low-stress resin cured product, the particle size is sufficiently smaller than the wavelength of light, specifically, the particle size is 0.1.
It has been proposed to fill the resin with ultrafine silica particles of less than μm. (Japanese Patent Application No. 3-133418)

[0003]

However, although the method of adding ultrafine silica particles to a resin as described above can reduce the internal stress of a cured resin and maintain its transparency, it is still resistant to heat. I am not satisfied with sex.

The present invention has been made in view of the above circumstances, and provides a semiconductor device resin-sealed with a sealing resin filled with ultrafine silica particles and excellent in low stress and heat resistance. In particular, the present invention provides an optical semiconductor device resin-encapsulated by a transparent encapsulating resin which is excellent in low stress and heat resistance.

[0005]

In order to achieve the above object, the semiconductor device of the present invention encapsulates a semiconductor element using a thermosetting resin composition containing the following components (A) to (C). Take the configuration. (A) Thermosetting resin. (B) Hardener component. (C) Silica particles having an amount of hydroxyl groups of 5 × 10 ⁻⁵ mol / g or less and a particle diameter of 0.1 μm or less.

In the course of a series of researches, the present inventors have found out that the hydroxyl groups on the surface of silica particles are largely involved in the adsorption of the curing agent component on the silica particles. That is, the inventors have found that Tg does not decrease when silica having a small amount of hydroxyl groups is used, and arrived at the present invention.

The thermosetting resin composition used in the present invention comprises a thermosetting resin (component A), a curing agent component (component B), and a hydroxyl group content of 5 × 10 ^-5 mol / g or less and particles. It is obtained by using silica particles (component C) having a diameter of 0.1 μm or less, and is usually in the form of a liquid, a powder, or a tablet formed by compressing this powder.

As the thermosetting resin (component A), an epoxy resin is particularly suitable, and there is no particular limitation such as a bisphenol type epoxy resin, an alicyclic epoxy resin, a novolac type epoxy resin, but for optical semiconductors. The transparent resin is preferably a bisphenol type epoxy resin or an alicyclic epoxy resin. Such an epoxy resin generally has an epoxy equivalent of 100 to 1000 and a softening point of 120 ° C.
The following are used: As the transparent resin for optical semiconductors, other epoxy resins may be used in combination with the former two epoxy resins, but the usage ratio is 5% of the total epoxy resin.
It is preferably set to 0% by weight or less.

The curing agent component includes a curing agent and a curing accelerator. The curing agent is not particularly limited, such as amine-based, acid anhydride-based, and phenol-based curing agents, but as the transparent resin for optical semiconductors, an acid anhydride-based curing agent is preferably used, and its molecular weight is Those of about 140 to 200 are suitable. Examples thereof include colorless to pale yellow acid anhydrides such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. The amount of the acid anhydride-based curing agent blended is used together with the transparent epoxy resin.
50 to 2 parts by weight with respect to 00 parts by weight (hereinafter, abbreviated as "part")
It is preferable to set it in the range of 00 parts. Further, examples of the curing catalyst include tertiary amines, imidazole compounds and organometallic complex salts.

In order to obtain the silica particles as the component (C), it is usually possible to reduce the number of hydroxyl groups on the surface by treating the silica particles at a high temperature. As another method, hexamethyldisilazane (hereinafter referred to as HMDS)
Alternatively, the amount of hydroxyl groups can be reduced by treating the hydroxyl groups on the surface of ordinary silica particles with a silane coupling agent. Furthermore, it is possible to more effectively reduce the amount of hydroxyl groups by treating the silica particles that have been subjected to high temperature treatment with HMDS or a silane coupling agent. Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, β- (3.4 epoxycyclohexyl) ethyltrimethoxysilane, and alkoxysilanes such as γ-aminopropyltriethoxysilane. When comparing HMDS as a treating agent with a silane coupling agent, HMDS is more preferable. The reason is that the HMDS is more excellent in heat resistance and low stress of the obtained semiconductor device.

The silica particles used in the present invention have an amount of hydroxyl groups and a particle diameter within the above-mentioned numerical ranges, but if the silica particles are out of these numerical ranges, the transparency, heat resistance and low stress are inferior. Because it will occur.

As the above silica particles (component C),
It may be used alone or in combination with ordinary silica. Even in that case, the amount of hydroxyl groups in the mixed silica is 5 × 10 ⁻⁵ m
It is preferably ol / g or less, more preferably 1 × 10 ⁻⁵ mol / g or less. At that time, the normal silica content is preferably 50% by weight or less based on the total silica content. Further, in that case, the total amount of silica particles is preferably set within a range of 10 to 90% by weight of the entire thermosetting resin composition. However, the particle size of silica, when the thermosetting resin composition is a transparent sealing resin, in order to maintain the transparency, it is necessary to have particles sufficiently smaller than the wavelength of light,
It is preferably 0.1 μm or less. The transparency of the transparent resin for optical semiconductors includes the case of being colored and transparent, and means that the cured product has a thickness of 1 mm and the light transmittance at a wavelength of 600 nm is 80 to 100%. (Measurement is by a spectrophotometer).

The amount of hydroxyl groups of silica can be determined by the following titration. 1. A known amount (2 g) of silica, 10 ml of ethanol, 2.5 g of a 10 wt% aqueous solution of a surfactant, and 140 ml of a 20 wt% aqueous solution of sodium chloride are mixed to prepare a silica dispersion. Emulgen 910 (manufactured by Kao Corporation) is used as the surfactant. 2. While stirring the silica dispersion, the pH is adjusted to 4.00 with 0.05N hydrochloric acid. 3. Next, a 0.05N aqueous solution of sodium hydroxide was gradually added dropwise with a buret, and the point where the pH was kept at 9.00 for 30 seconds was set as the end point. Calculate by

[Equation 1] X: normality of sodium hydroxide aqueous solution, in the above case X =
0.05 Y: drop amount of aqueous sodium hydroxide solution (ml) Z: mass of silica (g)

In the thermosetting resin composition used in the present invention, in addition to the above components (A) to (C), if necessary, a dye, a modifier, a discoloration preventing agent, an antiaging agent, a release agent. Conventionally known additives such as a reactive or non-reactive diluent can be appropriately added.

The thermosetting resin composition can be produced, for example, as follows. That is, the raw materials of the above components are appropriately blended, premixed, and then put in a kneader to be kneaded and melt-mixed. And after cooling it to room temperature,
It can be manufactured by a series of steps of crushing by known means and tableting if necessary. When the thermosetting resin composition is in a liquid state, it suffices to mix the above components. However, when the silica particles are ultrafine particles, as in Japanese Patent Application No. 4-116822, the silica ultrafine particles are previously dispersed in an organic solvent, then the dispersion liquid of the silica ultrafine particles and the resin component are mixed, and then the solvent is removed. Good.

The encapsulation of the semiconductor element using such a thermosetting resin composition is not particularly limited,
It can be carried out by a known molding method such as ordinary transfer molding or casting.

[0017]

EXAMPLES The present invention will be described below with reference to examples. Example 1 The particle size was 0.07 μm and the amount of hydroxyl groups was 20 × 10 ⁻⁵ mol.
The amount of hydroxyl groups was reduced to 0.8 × 10 ⁻⁵ mol / g by surface-treating the ultrafine silica particles having an amount of / g with HMDS. Bisphenol A type epoxy resin (liquid resin) having 200 parts of these ultrafine silica particles and an epoxy equivalent of 185
100 parts, 4-methylhexahydrophthalic anhydride 100
Parts, 2-ethyl-4-methylimidazole 0.4 parts, and antioxidant 2.5 parts were mixed to obtain an epoxy resin composition containing ultrafine silica particles. Example 2 Silica ultrafine particles 15 surface-treated with HMDS of Example 1
0 part, 80 parts of bisphenol A type epoxy resin (solid resin) having an epoxy equivalent of 650, 20 parts of triglycidyl isocyanurate (solid resin), 44 parts of tetrahydrophthalic anhydride, 2-ethyl-4-methylimidazole LE 0.4
Parts and 2.5 parts of an antioxidant were mixed to obtain an epoxy resin composition containing silica ultrafine particles. Example 3 The particle size dispersed in methyl isobutyl ketone is 0.01 μm.
The amount of hydroxyl groups was 0.5 × 10 5 by surface-treating silica ultrafine particles having a hydroxyl group amount of 40 × 10 ⁻⁵ mol / g in m (the silica ultrafine particles in the solvent was 30% by weight) with HMDS. ^-5 mol / g. Bisphenol A type epoxy resin 4 having an epoxy equivalent of 650 was added to 200 parts of this methyl ultrabutyl fine particle dispersion of silica.
0 part, 10 parts of triglycidyl isocyanurate and 22 parts of tetrahydrophthalic anhydride were dissolved. Then, this was depressurized to remove the solvent, and 2-ethyl-
0.2 parts of 4-methylimidazole and 1.2 parts of antioxidant were mixed to obtain an epoxy resin composition containing ultrafine silica particles. Example 4 In the same manner as in Example 3, except that the surface treatment was changed from HMDS to γ-glycidoxypropyltrimethoxysilane, ultrafine silica particles having a hydroxyl group amount of 4.6 × 10 ⁻⁵ mol / g were obtained and carried out. By the same operation as in Example 3, an epoxy resin composition containing ultrafine silica particles was obtained. Comparative Example 1 In Example 1, silica was not surface treated with HMDS. Comparative Example 2 In Example 2, the silica was not surface treated with HMDS. Comparative Example 3 In Example 3, silica was not surface treated with HMDS.

Next, using the epoxy resin compositions obtained in Examples 1 to 4 and Comparative Examples 1 to 3, a curing temperature of 150 ° C.
Then, the LED was resin-sealed to fabricate an optical semiconductor device, and the deterioration of energization luminance at high temperature of this optical semiconductor device was measured. The results are shown in Table 1 below. In addition, the measurement of the luminance deterioration by energization was performed as follows. That is, a constant current was passed through the optical semiconductor device (LED device), and the output current value of the light receiving element 5 seconds after the current application was calculated as the luminance and the deterioration rate was measured. The measuring condition is Ga of 0.5 × 0.5 mm evaluation element.
As a package, a pilot lamp having a diameter of 5 mm was used, and the luminance deterioration rate was 1000 hours after energization of 20 mA in an atmosphere of 80 ° C.

[0019]

[Table 1]

From the results shown in Table 1 above, the resins of Comparative Examples 1 to 3 have a low Tg, so that the heat resistance of the resins is low, the resins yellow due to thermal deterioration, and the light transmittance of the resins is greatly reduced, resulting in a decrease in luminance. Has deteriorated. On the other hand, in each of the examples, since the heat resistance of the resin was high, there was no heat deterioration and the deterioration of luminance was suppressed.

[0021]

As described above, according to the present invention, an optical semiconductor element is formed by a transparent encapsulating resin composition containing silica particles having a hydroxyl group amount of 5 × 10 ⁻⁵ mol / g or less and a particle diameter of 0.1 μm or less. Since it is sealed, the obtained optical semiconductor device is excellent in heat resistance, low stress and transparency. In the above description, the transparent encapsulating resin was taken as the thermosetting resin for explanation, but the technical idea of the present invention is also applied to improve heat resistance and low stress of resin encapsulating semiconductors in general. It is possible and therefore also useful when using thermosetting resins other than transparent thermosetting resins.

Claims (4)

[Claims] 1. A semiconductor device obtained by encapsulating a semiconductor element using a resin composition containing the following components (A) to (C). (A) Thermosetting resin. (B) Hardener component. (C) Silica particles having an amount of hydroxyl groups of 5 × 10 ⁻⁵ mol / g or less and a particle diameter of 0.1 μm or less. 2. The semiconductor device according to claim 1, wherein the silica particles as the component (C) are obtained by treating the silica particles with hexamethyldisilazane or a silane coupling agent. 3. A thermosetting resin composition for encapsulating a semiconductor device, which contains the following components (A) to (C). (A) Thermosetting resin. (B) Hardener component. (C) Silica particles having an amount of hydroxyl groups of 5 × 10 ⁻⁵ mol / g or less and a particle diameter of 0.1 μm or less. 4. The thermosetting resin composition for encapsulating a semiconductor device according to claim 3, wherein the silica particles as the component (C) are obtained by treating the silica particles with hexamethyldisilazane or a silane coupling agent.