JP3017888B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device sealed with a sealing resin having excellent heat resistance and low stress, and more particularly to an optical semiconductor device 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 a transparent epoxy resin, but there is a problem that elements are deteriorated due to internal stress of a cured resin. 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 cured resin, the wavelength is sufficiently smaller than the wavelength of light, specifically, the particle diameter is 0.1.
It has been proposed that ultrafine silica particles of less than μm be filled in the resin. (Japanese Patent Application No. 3-133418)

[0003]

However, the method of adding ultrafine silica particles to the resin as described above can reduce the internal stress of the cured resin and maintain the transparency, but it is still heat resistant. It is not satisfactory in sex.

The present invention has been made in view of such circumstances, and provides a semiconductor device resin-sealed with a sealing resin filled with ultra-fine silica particles and having excellent low-stress and heat resistance. In particular, an object of the present invention is to provide an optical semiconductor device resin-sealed with a transparent sealing resin excellent in low stress property and heat resistance.

[0005]

In order to achieve the above object, a semiconductor device of the present invention comprises a semiconductor element sealed with a thermosetting resin composition containing the following components (A) to (C). Take the configuration to do. (A) Thermosetting resin. (B) a curing agent component. (C) Silica particles having a hydroxyl group content of 5 × 10 ⁻⁵ mol / g or less and a particle size of 0.1 μm or less.

[0006] In the course of a series of studies, the present inventors have found that the hydroxyl groups on the surface of silica particles are greatly involved in the adsorption of a curing agent component onto silica particles. That is, it was found that when silica having a small amount of hydroxyl groups was used, Tg did not decrease, and the present invention was reached.

The thermosetting resin composition used in the present invention has a thermosetting resin (A component), a curing agent component (B component), a hydroxyl group content of 5 × 10 ⁻⁵ mol / g or less, and particles. It is obtained 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 obtained by compressing this powder.

As the thermosetting resin (component A), an epoxy resin is particularly preferable, and there is no particular limitation on bisphenol type epoxy resin, alicyclic epoxy resin, novolak type epoxy resin, etc. As the transparent resin, bisphenol-type epoxy resin and alicyclic epoxy resin are preferable. 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 an optical semiconductor, another epoxy resin may be used in combination with the former two epoxy resins.
It is preferable to set the content to 0% by weight or less.

[0009] The curing agent component includes a curing agent and a curing accelerator. The curing agent is not particularly limited, such as an amine-based, acid anhydride-based, and phenol-based curing agent.As the transparent resin for an optical semiconductor, preferably, an acid anhydride-based curing agent is used, and the molecular weight thereof is Those having about 140 to 200 are preferable. 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 is used together with the transparent epoxy resin.
50 to 2 parts by weight (hereinafter abbreviated as “parts”).
It is preferable to set in the range of 00 parts. Examples of the curing catalyst include tertiary amines, imidazole compounds and organometallic complex salts.

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

The silica particles used in the present invention have a hydroxyl group content and a particle diameter within the above-mentioned numerical ranges. However, if they are outside these numerical ranges, the disadvantages of inferior transparency, heat resistance and low stress property will result. For it will occur.

The silica particles (component (C)) include:
They may be used alone or in combination with ordinary silica. Also in this case, the amount of hydroxyl groups in the mixed silica is 5 × 10 ⁻⁵ m
ol / g or less is preferable, and 1 × 10 ⁻⁵ mol / g or less is still more preferable. At that time, the usage ratio of ordinary silica is desirably 50% by weight or less based on the total amount of silica. In this case, the total amount of the silica particles is desirably set in the 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 transparency, because particles that are sufficiently smaller than the wavelength of light are required,
It is desirable that the thickness be 0.1 μm or less. In addition, the transparency of the transparent resin for an optical semiconductor includes a case where the cured body is equivalent to a thickness of 1 mm and has a light transmittance of a wavelength of 600 nm of 80 to 100%, including a colored transparent case. (Measurement is by spectrophotometer).

The hydroxyl group content of silica can be determined by the following titration. 1. A silica dispersion is prepared by mixing a known amount (2 g) of silica, 10 ml of ethanol, 2.5 g of a 10% by weight aqueous solution of a surfactant, and 140 ml of a 20% by weight aqueous solution of sodium chloride. Emulgen 910 (manufactured by Kao Corporation) is used as the surfactant. 2. The pH of the silica dispersion is adjusted to 4.00 with 0.05N hydrochloric acid while stirring. 3. Next, a 0.05 N aqueous sodium hydroxide solution was gradually dropped with a burette, and the end point was a point at which the pH was maintained at 9.00 for 30 seconds. It is calculated by:

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

The thermosetting resin composition used in the present invention contains, if necessary, a dye, a denaturant, a discoloration inhibitor, an antioxidant, and a release agent, in addition to the components (A) to (C). Conventionally known additives such as a reactive or non-reactive diluent can be appropriately compounded.

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

The encapsulation of a 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 and casting.

[0017]

The present invention will be described below with reference to examples. Example 1 The particle diameter is 0.07 μm and the amount of hydroxyl groups is 20 × 10 ⁻⁵ mol.
/ G of silica ultra-fine particles was subjected to a surface treatment with HMDS to reduce the amount of hydroxyl groups to 0.8 × 10 ⁻⁵ mol / g. 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
Part, 2-ethyl-4-methylimidazole and 0.4 part of an antioxidant were mixed to obtain an epoxy resin composition containing ultrafine silica particles. Example 2 Ultrafine silica particles 15 surface-treated with HMDS of Example 1
0 parts, 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-methylimidazo- 0.4
Parts and 2.5 parts of an antioxidant were mixed to obtain an epoxy resin composition containing ultrafine silica particles. Example 3 Particle size dispersed in methyl isobutyl ketone is 0.01 μm
The ultrafine silica particles having a hydroxyl group content of 40 × 10 ⁻⁵ mol / g in m (the silica ultrafine particles in the solvent was 30% by weight) were subjected to a surface treatment with HMDS to reduce the hydroxyl group amount to 0.5 × 10 ⁵ mol / g. ^-5 mol / g. Bisphenol A type epoxy resin 4 having an epoxy equivalent of 650 was added to 200 parts of the silica ultrafine particle dispersion of methyl isobutyl ketone.
0 parts, 10 parts of triglycidyl isocyanurate and 22 parts of tetrahydrophthalic anhydride were dissolved. After removing the solvent under reduced pressure, 2-ethyl- as a curing catalyst was used.
0.2 parts of 4-methylimidazole and 1.2 parts of an antioxidant were mixed to obtain an epoxy resin composition containing ultrafine silica particles. Example 4 Ultrafine silica particles having a hydroxyl group content of 4.6 × 10 ⁻⁵ mol / g were obtained in the same manner as in Example 3 except that the surface treatment was changed from HMDS to γ-glycidoxypropyltrimethoxysilane. By the same operation as in Example 3, an epoxy resin composition containing ultrafine silica particles was obtained. Comparative Example 1 In Example 1, the 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, the 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, an LED was resin-sealed to produce an optical semiconductor device, and deterioration of the current-carrying luminance of the optical semiconductor device at a high temperature was measured. The results are shown in Table 1 below. In addition, the measurement of energization luminance deterioration was performed as follows. That is, a constant current was applied to the optical semiconductor device (LED device), and the output current value of the light receiving element 5 seconds after current application was determined as luminance, and the deterioration rate was measured. The measurement conditions were as follows.
As, As, a package, using a pilot lamp having a diameter of 5 mm, in a 80 ° C. atmosphere, the luminance deterioration rate after 1000 hours of 20 mA current supply.

[0019]

[Table 1]

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

[0021]

As described above, in the present invention, an optical semiconductor device is produced by a transparent encapsulating resin composition using silica particles having a hydroxyl group content of 5 × 10 ⁻⁵ mol / g or less and a particle size of 0.1 μm or less. Because of the sealing, the obtained optical semiconductor device is excellent in heat resistance, low stress, and transparency. In the above description, the transparent encapsulating resin has been described as the thermosetting resin. However, the technical idea of the present invention is also applied to improve the heat resistance and the low stress of the entire resin-encapsulated semiconductor. It is possible, and thus is useful when using a thermosetting resin other than a transparent thermosetting resin.

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Claims (4)

(57) [Claims] 1. A semiconductor device having a semiconductor element encapsulated with a resin composition containing the following components (A) to (C). (A) Thermosetting resin. (B) a curing agent component. (C) Silica particles having a hydroxyl group content of 5 × 10 ⁻⁵ mol / g or less and a particle size 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 sealing a semiconductor element, comprising the following components (A) to (C). (A) Thermosetting resin. (B) a curing agent component. (C) Silica particles having a hydroxyl group content of 5 × 10 ⁻⁵ mol / g or less and a particle size of 0.1 μm or less. 4. The thermosetting resin composition for sealing a semiconductor element 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.