JPH06232296A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide an optical semiconductor device resin-sealed by transparent sealing resin especially excellent in the low stress and heat-resisting properties by providing a semiconductor device resin-sealed by sealing resin excellent in the low stress and heat-resisting properties. CONSTITUTION:A semiconductor device is sealed by a resin composite containing thermosetting resin, a curing agent component and silica particles having a grain diameter not exceeding 0.5mum and an acidity titrated by butylamine not exceeding 0.01mmol/g.

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 excellent in heat resistance and low stress, and more 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 a transparent epoxy resin, but there is a problem that the element is deteriorated by the internal stress of a cured resin. For example, in the case of an LED (light emitting diode), the brightness decreases. Therefore, the inventors of the present invention, in order to obtain a transparent and low stress resin cured body,
It is sufficiently smaller than the wavelength of light, specifically, the particle size is 0.
It has been proposed to fill the resin with ultrafine silica particles of 5 μm or less. (Japanese Patent Application No. 3-183482 and Japanese Patent Application No. 3-1
33418).

[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 with a transparent encapsulation resin having low stress and excellent 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 a particle size of 0.5 μm or less and an acidity titrated with butylamine of 0.01 mmol / g or less.

In the course of a series of studies, the present inventors have found that when silica particles having a particle size of 0.5 μm or less and an acidity titrated with butylamine of more than 0.01 mmol / g (mmol / g) are used. The Tg of the cured product is low and the heat resistance is poor, but the acidity is 0.01 mmol /
The inventors have found that the Tg of a resin cured product does not decrease when silica particles of g or less are used, and have reached the present invention.

Thermosetting resin (component A) used in the present invention,
A curing agent component (B component) and a particle size of 0.5 μm or less and an acidity of 0.01 when titrated with butylamine.
It is obtained by using silica particles (C component) of mmol / g or less, and is usually in the form of liquid, powder, or tablets obtained by tableting this powder.

As the thermosetting resin (component A), an epoxy resin is particularly suitable, and a bisphenol type epoxy resin, an alicyclic epoxy resin, a novolac type epoxy resin, an isocyanurate type epoxy resin, etc. are particularly preferable. Although not limited, bisphenol type epoxy resin and alicyclic epoxy resin are preferable as the transparent resin for optical semiconductors.
In some cases, other epoxy resin such as triglycidyl isocyanurate may be used in combination. When the other epoxy resin is used in combination, it is generally preferable that the blending ratio is set to 50% by weight (hereinafter abbreviated as “%”) or less of the entire epoxy resin component. Such an epoxy resin generally has an epoxy equivalent of 100 to 1
000 and a softening point of 120 ° C. or less are used. The transparency of the transparent resin includes the case of being colored and transparent, and has a light transmittance of 5 at a wavelength of 600 nm at a thickness of 1 mm.
It refers to 0 to 100%, preferably 80 to 100%. (Measured by spectrophotometer).

The curing agent component (B 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, acid anhydride-based curing agents are preferably used. Examples thereof include colorless to pale yellow acid anhydrides such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methyltetrahydrophthalic anhydride. The compounding amount of the acid anhydride-based curing agent is 1 of the above epoxy resin.
It is preferable to set in the range of 0.5 to 1.3 equivalents with respect to the equivalent.

Examples of the curing accelerator include tertiary amines, quaternary ammonium salts, imidazole compounds, boron compounds and organometallic complex salts.

As the tertiary amine, triethanolamine, tetramethylhexanediamine, triethylenediamine, dimethylaniline, dimethylaminoethanol,
Diethylaminoethanol, 2,4,6-tris (dimethylaminomethyl) phenol, N, N ^, -dimethylpiperazine, pyridine, picoline, 1,8-diaza-bicyclo (5,4,0) undecene-7 , Benzyldimethylamine, and 2- (dimethylamino) methylpheno-
And the like. Examples of the quaternary ammonium salt include dodecyltrimethylammonium chloride, cetyltrimethylammonium chloride, benzyldimethyltetradecylammonium chloride and stearyltrimethylammonium chloride. Examples of the imidazoles include 2-methylimidazole, 2-undecylimidazole, 2-ethylimidazole, 1-benzyl-2-methylimidazole and 1-cyanoethyl-2-undecylimidazole. And the like. As the boron compound, tetraphenylboron salts, for example,
Triethyleneamine tetraphenylborate and N-
Methylmorpholine tetraphenylborate can be mentioned. Examples of the organic metal complex salt include phosphate.

In order to obtain the above-mentioned (C component) silica particles, the silanol group on the surface of the silica particles is treated by mixing silica particles of 0.5 μm or less with an organic component in an organic solvent. It is possible to reduce the acidity of the silica particles or to make them basic. (Here, the term "basic" means that it shows a yellow color when p-dimethylaminoazobenzene is added to the silica dispersion as an indicator.) The method is as follows. (1) A silanol group on the surface of silica particles is neutralized with an organic amine. Examples of organic amines include ethylamine, butylamine and monoethanolamine. (2) A silanol group on the surface of silica particles is treated with an acid anhydride. Examples of the acid anhydride include acetic anhydride, phthalic anhydride, benzoic anhydride, maleic anhydride, succinic anhydride, and the acid anhydrides used as the curing agent in the present invention described above. (3) A silanol group on the surface of silica particles is treated with an organic carboxylic acid. Examples of the organic carboxylic acid include acetic acid, benzoic acid, acrylic acid, methyl acrylic acid, ethyl acrylic acid and butyl acrylic acid. (4) The silanol groups on the surface of silica particles are treated with silane. Examples of the silane include alkoxysilane and chlorosilane, and examples thereof include triethylmonoethoxysilane, triethylmonomethoxysilane, trimethylmonomethoxysilane, trimethylchlorosilane and dimethyldichlorosilane. (5) A silanol group on the surface of silica particles is treated with a silane coupling agent. Examples of the silane coupling agent include those having the structures shown in Chemical formulas 1 to 10.

[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical 4]

[Chemical 5]

[Chemical 6]

[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical 10] In the above Chemical Formulas 1 to 10, n is 0, 1 or 2. (6) The silanol group on the surface of silica particles is treated with hexamethyldisilazane.

The acidity in the present invention was determined by the following measuring method. 10 containing about 0.2 to 1 g of silica
~ 20 ml of a dispersion of silica particles (the dispersion medium is not particularly limited as long as it is neutral, but methyl isobutyl ketone, methyl ethyl ketone, xylene, ethyl acetate, acetone, butyl alcohol, ethyl alcohol, etc. are preferable) as an indicator. Add a few drops of a solution of p-dimethylaminoazobenzene in methyl ethyl ketone (0.1%). At this point, if the dispersion is acidic, it will appear red, and if it is basic, it will appear yellow. In the case of exhibiting a red color, titration is carried out with an acetone solution of 5 × 10 ⁻⁴ N butylamine, and the point at which the red color of the indicator changes to yellow is taken as the end point of the titration. Where silica 1
The acidity of silica is defined as the number of moles of butylamine required for titration per gram. In the present invention, the silica particles having an acidity of 0.01 mmol / g or less are used. In the present invention, the silica particles having an acidity of 0.01 mmol / g or less include basic silica particles. If the acidity of more than 0.01 mmol / g is used, the Tg of the cured product is lowered and the heat resistance is poor. Further, if silica particles having a particle diameter of more than 0.5 μm are used, the cured product has the drawbacks of low stress and poor transparency. In the present invention, the term (acidic or basic) means that the coloration when p-dimethylaminoazobenzene is used as an indicator is red and the coloration is yellow when the coloration is basic.

When the particle size of silica is 0.02 μm or less and the cured epoxy resin composition mainly composed of the above-mentioned epoxy resin (component A) and curing agent component (component B) is transparent, the resin composition Is transparent. Silica particle size is 0.0
When it is larger than 2 μm, it becomes cloudy, but in that case, it can be made transparent by making the difference in refractive index between the silica particles and the cured epoxy resin composition equal (± 0.01). Examples of the refractive index adjusting method include the following methods (1) to (3). (1) A method of adjusting the refractive index of only a cured product of an epoxy resin composition. (For example, selection of type of epoxy resin, combination of two or more kinds of epoxy resin, combination of two or more kinds of curing agent, etc.). (2) A method of adjusting the refractive index of silica particles. (3) A method of using the above (1) and (2) together.

Preferably, the silica particles themselves have a controlled refractive index. Specifically, the silica particles themselves are refracted by mixing a trace amount of a metal oxide such as lead oxide or titanium oxide. It is common to adjust the index (usually about 1,40) to approximate the refractive index of the epoxy resin (usually about 1.50). Details of these are described in JP-A-3-20.
1470.

However, when the content of silica particles is 20% by weight or less of the whole epoxy resin composition, the particle size is 0.
Even in the range of 02 to 0.5 μm, it is possible to obtain transparency that can be used for a specific optical semiconductor.

The content of silica particles is preferably set within the range of 10 to 80% by weight based on the whole epoxy resin composition. When the silica particles are less than 10% by weight, the low stress property of the cured product is not sufficiently expressed, and when it exceeds 80% by weight, the low stress property is obtained but the viscosity of the resin tends to be high and the moldability tends to be poor. Because it will be done. The content can be calculated from the weight of the silica particles remaining as ash after burning the cured product of the transparent epoxy resin composition.

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, a release agent, and reactivity. Conventionally known additives such as a non-reactive diluent can be appropriately blended.

The thermosetting resin composition can be manufactured, 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, it is preferable to disperse the silica ultrafine particles in an organic solvent in advance, then mix the dispersion liquid of the silica ultrafine particles and the resin component, and then remove the solvent. For details of these, Japanese Patent Application No. 4-11
6822.

The sealing 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. When the optical semiconductor element is encapsulated with the transparent epoxy resin composition, an optical semiconductor device is obtained. At this time, the transparency of the cured composition is
Including the case of colored and transparent, the light transmittance at a wavelength of 600 nm at a thickness of 1 mm is 50 to 100%, preferably 80 to 1
Say 00%. (Measured by spectrophotometer).

[0021]

EXAMPLES Next, examples will be described together with comparative examples.

Example 1 Particle size of 0.01 dispersed in methyl isobutyl ketone
The surface of μm silica particles was treated with butylamine.
[A yellow color was obtained when p-dimethylaminoazobenzene was added as an indicator to this silica dispersion (silica content; 30% by weight). Therefore, the acidity of the silica particles is 0.01 mmol / g or less without titration. To 670 parts of the silica dispersion thus obtained, 100 parts of a bisphenol A type epoxy resin (liquid resin) having an epoxy equivalent of 185 and 100 parts of methylhexahydrophthalic anhydride.
The parts were dissolved. Then, this was depressurized and desolvated, and then 0.4 parts of 2-ethyl-4-methylimidazole as a curing accelerator and 2.5 parts of an antioxidant were mixed to obtain a silica particle-containing transparent resin composition. Obtained.

Example 2 To 240 parts of the silica dispersion of Example 1 was added an epoxy equivalent of 64.
0 bisphenol A type epoxy resin (solid resin) 40
Parts, 10 parts of triglycidyl isocyanurate and 22 parts of tetrahydrophthalic anhydride were dissolved. Then, this was depressurized to remove the solvent, and then 0.2 parts of 2-ethyl-4methylimidazole as a curing accelerator and 1.2 parts of an anti-aging agent.
The parts were mixed to obtain a transparent resin composition containing silica particles.

Example 3 A silica particle-containing transparent resin composition was obtained in the same manner as in Example 1, except that the surface treatment of the silica particles was performed with the silane coupling agent of Chemical formula 11.

[Chemical 11]

Comparative Example 1 In Example 1, a silica particle-containing transparent resin composition was obtained without treating the silica particles with butylamine. (In this case, the acidity of the silica dispersion was 0.03 mmol / g.)

Comparative Example 2 In the same manner as in Comparative Example 1 in Example 2, a silica particle-containing transparent resin composition was obtained without treating the silica particles with butylamine. (In this case, the silica dispersion has an acidity of 0.03
It was mmol / g. )

Next, using the epoxy resin compositions obtained in Examples 1 to 3 and Comparative Examples 1 and 2, the curing temperature was 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. In addition, the measurement of the deterioration of energization luminance 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 measurement conditions are as follows: Evaluation element 0.5 × 0.5 mm GaAs, package
A pilot lamp with a diameter of 5 mm is used as the
It is the luminance deterioration rate 1000 hours after 20 mA energization in an atmosphere of 0 ° C.

[0028]

[Table 1]

From the results in Table 1 above, the resins of Comparative Examples 1 and 2 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 brightness. Deteriorated. On the other hand, in each of the examples, since the cured resin had high heat resistance, there was no thermal deterioration and luminance deterioration was suppressed.

[0030]

INDUSTRIAL APPLICABILITY As described above, in the present invention, a transparent sealing resin composition comprising silica particles having a particle size of 0.5 μm or less and an acidity titrated with butylamine of 0.01 mmol / g or less. Since the optical semiconductor element is sealed by the above, the obtained optical semiconductor device is excellent in heat resistance, low stress and transparency. In the above description, a transparent epoxy resin is taken as the thermosetting resin for explanation, but the technical idea of the present invention is to improve heat resistance and low stress of resin-encapsulated semiconductors in general. It is applicable and is therefore also useful when using thermosetting resins other than transparent thermosetting resins.

Claims (2)

[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 a particle size of 0.5 μm or less and an acidity titrated with butylamine of 0.01 mmol / g or less. 2. A resin composition for encapsulating a semiconductor element, which contains the following components (A) to (C). (A) Thermosetting resin. (B) Hardener component. (C) Silica particles having a particle size of 0.5 μm or less and an acidity titrated with butylamine of 0.01 mmol / g or less.