JP3394736B2 - Epoxy resin composition and semiconductor device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is preferably used for encapsulating an epoxy resin composition and a semiconductor device, more specifically, a semiconductor element such as IC and LSI and an optical semiconductor element such as LED and CCD. The present invention relates to an epoxy resin composition, and a semiconductor device obtained by sealing a semiconductor element with the epoxy resin composition.

[0002]

2. Description of the Related Art Currently, many semiconductor devices (including optical semiconductor devices) are manufactured by encapsulating semiconductor elements (including optical semiconductor elements) with an epoxy resin composition. The sealing of the semiconductor element with the epoxy resin composition is performed by injecting the epoxy resin composition into a mold in which the semiconductor element is installed at a predetermined position and curing the epoxy resin composition.
In the epoxy resin composition used for such encapsulation, an acid anhydride-based curing agent is often used as a curing agent for the epoxy resin, and especially for an optical semiconductor element such as an LED or a CCD that requires transparency. It is known to be very useful for sealing.

[0003]

However, in the manufacture of such a semiconductor device, it is desired to quickly cure the epoxy resin in order to improve the production efficiency.
Although it is conceivable that the epoxy resin is cured at a high temperature in order to be rapidly cured, for example, when the epoxy resin is cured at a temperature of about 130 ° C. or higher, the acid anhydride-based curing agent is decomposed to generate carbon dioxide gas,
The generated carbon dioxide gas bubbles not only cause defects in the cured resin, but also cause the carbon dioxide gas bubbles at the interface between the mold and the resin to cause sink marks on the surface of the cured resin. Become.

The present invention has been made in view of the above circumstances, and an object thereof is to cure even at a high temperature.
Less carbon dioxide and less sink marks,
The present invention provides an epoxy resin composition and a semiconductor device obtained by encapsulating a semiconductor element using the epoxy resin composition.

[0005]

In order to achieve the above object, the epoxy resin composition of the present invention comprises an epoxy resin and an acid.
Anhydrous curing agent, organic acid of diazabicycloalkenes
Acid anhydride curing agent containing salt and metal organic acid salt
The presence of diazabicycloalkenes relative to 100 parts by weight
2.5 to 8 parts by weight of organic acid salt, 1 to 6 parts by weight of metal organic acid salt
It is characterized by containing parts .

The present invention also provides an epoxy resin and an acid anhydride.
-Based curing agents, organic acid salts of diazabicycloalkenes, and
And 100 weight of acid anhydride type curing agent containing a metal organic acid salt.
An organic acid salt of diazabicycloalkenes is used for each part.
2.5-8 parts by weight, 1-6 parts by weight of metal organic acid salt
And carbon dioxide gas generation amount when heated for 20 minutes at 135 ° C. is at 200 [mu] g / g or less, but also the epoxy resin composition.

The present invention also includes a semiconductor device obtained by encapsulating a semiconductor element using the above epoxy resin composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin composition of the present invention comprises
Epoxy resin , acid anhydride type curing agent, diazabicycloal
It contains organic acid salts of kens and metal organic acid salts .

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurate, hydantoin epoxy resin and the like. Nitrogen-containing cyclic epoxy resin, water-added bisphenol A type epoxy resin, aliphatic epoxy resin, glycidyl ether type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, which is the mainstream of low water absorption cured type, dicyclo ring Type epoxy resin, naphthalene type epoxy resin and the like. These may be used alone or in combination. Among these epoxy resins, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, which is excellent in transparency and discoloration resistance for encapsulating optical semiconductor elements,
It is preferable to use an alicyclic epoxy resin or triglycidyl isocyanurate.

The above-mentioned epoxy resin may be solid or liquid at room temperature, but generally has an epoxy equivalent of 90 to 1000.
Are preferable, and in the case of solid, the softening point is
It is preferably 160 ° C. or lower. If the epoxy equivalent is less than 90, the cured product of the epoxy resin composition may become brittle. Further, when the epoxy equivalent exceeds 1000, the glass transition temperature (Tg) of the cured product may be lowered.

Examples of the acid anhydride type curing agent include, for example,
Phthalic anhydride, maleic anhydride, trimellitic anhydride,
Pyromellitic dianhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic acid anhydride, nadic acid anhydride, glutaric anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and the like can be mentioned. These may be used alone or in combination. Among these acid anhydride type curing agents, it is preferable to use phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride and methylhexahydrophthalic anhydride.

The acid anhydride type curing agent has a molecular weight of
It is preferably about 140 to 200, and colorless to pale yellow acid anhydride is preferable.

In addition to the acid anhydride-based curing agent, conventionally known epoxy resin curing agents such as amine-based curing agents, phenol-based curing agents, and acid anhydride-based curing agents are partially esterified with alcohol. Or a curing agent for a carboxylic acid such as hexahydrophthalic acid, tetrahydrophthalic acid or methylhexahydrophthalic acid may be used in combination. In that case, these curing agents may be used alone or in combination. For example, when a carboxylic acid curing agent is used in combination, the curing rate can be increased and the productivity can be improved.

The mixing ratio of the epoxy resin and the acid anhydride type curing agent is such that the acid anhydride group in the acid anhydride type curing agent is 0.5 with respect to 1 equivalent of the epoxy group in the epoxy resin.
It is preferable that the ratio is about 1.5 equivalents, more preferably 0.7 to 1.2 equivalents. If the acid anhydride group is less than 0.5 equivalent, the curing rate of the epoxy resin composition may be slow and the glass transition temperature of the cured product may be low, while if it exceeds 1.5 equivalent. May have reduced moisture resistance.

Even when a curing agent other than the above-mentioned acid anhydride-based curing agent is used in combination, the blending ratio is in accordance with the blending ratio (equivalent ratio) when the acid anhydride-based curing agent is used. Good.

The epoxy resin composition of the present invention also comprises
A curing accelerator is added, and as such a curing accelerator , carbon dioxide gas is not generated when the epoxy resin composition is thermally cured.
1,8-Diaza- to reduce rawness and prevent sink marks
Bicyclo (5,4,0) undecene-7 (hereinafter "DB
U ”), 1,5-diazabicyclo (4,3,
0) An organic acid salt of diazabicycloalkene such as nonene-5 (hereinafter referred to as “DBN”) is used . More specifically, an organic acid salt of diazabicycloalkene and an organic acid such as orthophthalic acid, carboxylic acid, or octylic acid is used .

The ratio of the organic acid salt of diazabicycloalkenes to be added is 100 parts by weight of the curing agent.
2.5 to 8 parts by weight . Further, 2.5 to 4.5 parts by weight, especially, is preferably 2.5 to 4.2 parts by weight. If the content of the organic acid salt of diazabicycloalkene is less than 2.5 parts by weight, the rapid curing property may decrease, and if it exceeds 8 parts by weight, the amount of carbon dioxide gas generated May increase and sink marks may occur.

Further, together with the organic acid salt of the diazabicycloalkenes , metal organic acid is added to prevent sink marks.
Use salt together . Examples of such metal organic acid salts include tin octylate, zinc octylate, tin naphthenate, and zinc naphthenate.

The content of the metal organic acid salt is 1 to 6 parts by weight with respect to 100 parts by weight of the curing agent . Further, it is preferably 2 to 5 parts by weight. When the content of the metal organic acid salt is less than 1 part by weight, the effect of using the organic acid salt of the diazabicycloalkene may not be sufficient, and when it exceeds 6 parts by weight, The rapid curing property may decrease.

As the curing accelerator, a salt other than the organic acid salt of diazabicycloalkene may be used. Examples of such a curing accelerator include DBU,
Tertiary amines such as DBN and triethylenediamine, 2
Imidazoles such as -ethyl-4-methylimidazole and 2-methylimidazole, phosphorus compounds such as triphenylphosphine, tetraphenylphosphonium tetraphenylborate, tetra-n-butylphosphonium-o, o-diethylphosphorodithioate, 4 Examples thereof include primary ammonium salts and their derivatives. These may be used alone or in combination.

The epoxy resin composition of the present invention contains
The epoxy resin, a curing agent such as the acid anhydride-based curing agent, other than the curing accelerator, if necessary, conventionally used, for example, deterioration inhibitor, modifier, filler,
Various known additives such as a silane coupling agent, a defoaming agent, a leveling agent, a release agent, a dye and a pigment may be appropriately blended.

Examples of the deterioration preventing agent include conventionally known deterioration preventing agents such as phenol compounds, amine compounds, organic sulfur compounds and phosphine compounds. Examples of the modifier include conventionally known modifiers such as glycols, silicones and alcohols. As the filler, for example,
Conventionally known fillers such as silica particles and alumina particles can be used. As the silane coupling agent,
For example, conventionally known silane coupling agents such as silane type and titanate type are mentioned. Examples of the defoaming agent include conventionally known defoaming agents such as silicone-based agents.

The epoxy resin composition of the present invention is
For example, by manufacturing as follows,
It can be obtained in the form of powder or a tablet obtained by compressing the powder. That is, in order to obtain a liquid epoxy resin composition, for example, the above-mentioned components may be appropriately mixed. Further, in order to obtain a powder form or a tablet form obtained by compressing the powder, for example, the above-mentioned respective components are appropriately blended, pre-mixed, kneaded by using a kneader and melt-mixed, and then, After cooling this to room temperature, it may be crushed by a known means and tableted if necessary.

The epoxy resin composition of the present invention obtained in this way, carbon dioxide gas generation amount when heated at 135 ° C. 20 min, 500 [mu] g / g or less, preferably, 300
It is less than or equal to μg / g, and more preferably less than or equal to 200 μg / g. In addition, "μg / g" means the epoxy resin composition 1
It is the amount of carbon dioxide gas generated per g (μg).

The amount of carbon dioxide gas generated can be measured using, for example, a Kitagawa gas detector tube for carbon dioxide gas. The Kitagawa gas detector tube is an acid-base indicator (CO ₂ + 2KOH → K ₂ CO _{3) that} develops color by an acid-base reaction.
2H ₂ O) filled gas detector tube for detecting the amount of carbon dioxide gas by sucking the sample gas by the vacuum method and checking the color change range of the acid-base indicator. More specifically, the amount of carbon dioxide gas generated is measured by, for example, 12 mm × 40 in a closed container (volume: 200 ml).
Epoxy resin composition 1 on a plane of mm (4.8 cm ² ).
After expanding g and heating at 135 ° C for 20 minutes, the air in the closed container is sucked by the Kitagawa gas detector tube for carbon dioxide, and the carbon dioxide contained in the air is quantified. , Can be measured. The amount of carbon dioxide gas generated during thermosetting of the epoxy resin composition is 500 μg / g or less.
Lower, preferably 300 μg / g or less, more preferably
Is 200 μg / g or less, it is possible to obtain a cured product having a good shape with no sink even when cured at high temperature.

The epoxy resin composition of the present invention as described above can be suitably used for encapsulating semiconductor elements. The epoxy resin composition of the present invention can be used to seal a semiconductor element without particular limitation, and it can be carried out by a known molding method such as ordinary transfer molding or casting. When the epoxy resin composition of the present invention is in liquid form, it may be used as a so-called two-liquid type in which at least the epoxy resin and the curing agent are separately stored and mixed immediately before use. Further, when the epoxy resin composition of the present invention is in the form of powder or tablet, it is only necessary to set the B-stage when each component is melt-mixed, and heat-melt it during use.

The semiconductor element to be sealed is not particularly limited, and semiconductor elements such as IC and LSI, and
Examples include optical semiconductor elements such as LEDs and CCDs.
The obtained semiconductor device may or may not be transparent, but in the epoxy resin composition of the present invention, an acid anhydride-based curing agent is used as a curing agent, which is excellent in transparency. Therefore, in particular, it can be suitably used for an optical semiconductor element in which a transparent cured body is required. The term “transparent” includes a case of being colored and transparent, having a thickness of 1 mm and having a light transmittance of 5 at a wavelength of 600 nm as measured by a spectrophotometer.
It means 0 to 100%, preferably 80 to 100%.

In the epoxy resin composition of the present invention, when the semiconductor element is sealed, for example, 130 to 14
Even if it is hardened at a high temperature of 0 ° C. or 140 to 160 ° C., since a carbon dioxide gas is less generated, a semiconductor device having a good shape with few defects and less sink marks on the surface is manufactured with high production efficiency. be able to.

[0029]

EXAMPLES The present invention will be described in more detail below by showing Examples and Comparative Examples, but the present invention is not limited to the Examples and Comparative Examples.

1) Preparation of Epoxy Resin Composition Example 1 was prepared by adding the curing accelerator and the metal organic acid salt shown in Table 1 to the epoxy resin composition having the composition shown below in the proportions shown in Table 1. 6 and the epoxy resin compositions of Comparative Examples 1 to 11 were prepared.

Composition of epoxy resin composition: parts by weight bisphenol A type epoxy resin (epoxy equivalent 185) 100 acid anhydride curing agent (4-methylhexahydrophthalic anhydride 100 / hexahydrophthalic anhydride (weight ratio 7 / 3)) silicone-based defoaming agent 0.0175 & antidegradants 1.3 2) carbon dioxide emissions examples 1 6 and the epoxy resin composition 1g of Comparative example 1 to 11, 12 mm × 40 mm Each is spread on a flat surface of (4.8 cm ² ), heated in a 200 ml closed container at 135 ° C. for 20 minutes, and then the air in the closed container is sucked with a Kitagawa gas detector tube for carbon dioxide gas. , Was determined by quantifying the carbon dioxide gas contained in the air. The results are shown in Table 1.

3) Evaluation The epoxy resin compositions of Examples 1 to 6 and Comparative Examples 1 to 11 were evaluated for sink rate and rapid curing property. The results are shown in Table 1.

Occurrence rate of sink marks: Using a lamp case die having a diameter of 5 mm, Examples 1 to 6 and Comparative Examples 1 to 1
By curing the epoxy resin composition No. 1 at 150 ° C. for 15 minutes or at 140 ° C. for 20 minutes, 60 cured products were obtained for each epoxy resin composition. Regarding the obtained cured product, the presence or absence of sink marks was visually confirmed, and the number of cured products having sink marks was divided by the total number of cured products (60) to obtain a sink rate (%). ) Was asked.

Fast-curing property: Using a lamp case mold having a diameter of 5 mm, the epoxy resin compositions of Examples 1 to 6 and Comparative Examples 1 to 11 were heated at 150 ° C. for 15 minutes, or
A cured product was obtained by curing each at 140 ° C. for 20 minutes. The glass transition temperature (Tg (° C.)) was determined by measuring the obtained cured product with DSC (manufactured by Perkin Elmer Co., Ltd., temperature rising rate: 10 ° C./min), and this Tg was used as an index for rapid curing. did.

[0035]

[Table 1] Table As is apparent from the table below stage 1, whereas the epoxy resin composition of Comparative Example 6 carbon dioxide generating amount is 478μg / g, the incidence of sink marks at 140 ° C. curing is 0% In the epoxy resin composition of Comparative Example 9 in which the carbon dioxide gas generation amount was 552 μg / g, the sink rate in curing at 140 ° C. was 20%, and the carbon dioxide gas generation amount was 500 μg / g.
It can be seen that the rate of occurrence of sink marks changes at g.

Further, as also apparent from the table below stages in Table 1, carbon dioxide gas generation amount is 294μg / g Comparative Example
In the epoxy resin composition of No. 4 , the sink rate at 150 ° C. curing is 10%, while the carbon dioxide gas generation rate is 37%.
In the epoxy resin composition of Comparative Example 5 which is 2 μg / g,
The rate of sink marks when curing at 150 ° C is 40%,
The occurrence rate of sink marks changes with the carbon dioxide gas generation rate of 300 μg / g as a boundary, and the more preferable carbon dioxide gas generation rate is 30.
It can be seen that it is 0 μg / g or less.

Further, Comparative Example 1 mixing ratio of the curing accelerator is 1.1 parts by weight, whereas the Tg of 110 ° C., the mixing ratio of the curing accelerator is 4.2 parts by weight Comparative An example
No. 4 has a Tg of 141 ° C., and it can be seen that the one having a small proportion of the curing accelerator has a slightly lower rapid curing property than the one having a large proportion.

[0038] As apparent from Table stages above the table 1, together with a curing accelerator that mixing metal organic acid salt,
It can be seen that the amount of carbon dioxide gas generated is further reduced.

[0039]

As described above, in the epoxy resin composition of the present invention, when the semiconductor element is sealed, even if the epoxy resin composition is cured at a high temperature, carbon dioxide gas is less generated, so that there are few defects.
In addition, a semiconductor device with a good shape with less sink marks on the surface,
It can be manufactured with high production efficiency.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-129224 (JP, A) JP-A-54-127458 (JP, A) JP-A-7-316263 (JP, A) JP-A-7- 288330 (JP, A) JP 61-194756 (JP, A) JP 1-126322 (JP, A) JP 7-25988 (JP, A) JP 63-304018 (JP, A) JP-A-6-337408 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 59/42 C08G 59/40 H01L 23/29

Claims (3)

(57) [Claims] 1. An epoxy resin, an acid anhydride-based curing agent, and a dia
Organic acid salts of zabicycloalkenes and metal organic acids
Containing a salt, based on 100 parts by weight of the acid anhydride curing agent,
2.5-8 weight of organic acid salt of diazabicycloalkene
Parts, 1 to 6 parts by weight of metal organic acid salt
Epoxy resin composition to be collected. 2. An epoxy resin, an acid anhydride-based curing agent, and a dia
Organic acid salts of zabicycloalkenes and metal organic acids
Containing a salt, based on 100 parts by weight of the acid anhydride curing agent,
2.5-8 weight of organic acid salt of diazabicycloalkene
Part, 1 to 6 parts by weight of a metal organic acid salt, and the amount of carbon dioxide gas generated when heated at 135 ° C. for 20 minutes is 2
An epoxy resin composition, which is at most 100 μg / g. 3. The epoxy resin according to claim 1 or 2.
Obtained by encapsulating a semiconductor element with the composition
A semiconductor device characterized by being provided.