KR20190053058A - Composition for encapsulating semiconductor device and semiconductor device encapsulated by using the same - Google Patents

Abstract

An epoxy resin composition for encapsulating a semiconductor device of the present invention is a composition comprising an epoxy resin, a curing agent, and a filler, wherein the filler contains a meta-aramid having an aspect ratio of 10 to 200, and the meta-aramid is contained in the composition in an amount of 0.01 to 1 wt%.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for encapsulating semiconductor devices and a semiconductor device encapsulated with the epoxy resin composition.

TECHNICAL FIELD The present invention relates to an epoxy resin composition for sealing a semiconductor device and a semiconductor device sealed by using the same.

A method for sealing a semiconductor element with an epoxy resin composition is commercially performed for the purpose of protecting the semiconductor element from external environmental factors such as moisture and mechanical impact. Recently, as small and thin digital devices become common, the degree of integration of semiconductor devices is improved day by day, and the chip is being stratified and densified.

As semiconductor chips become thinner, higher integration and / or surface mounting increases with the trend of miniaturization, weight reduction, and high performance, there is a problem that can not be solved by conventional epoxy resin compositions.

Particularly, there is a demand for a semiconductor device having a warping phenomenon and excellent reliability as a semiconductor device is made thin and left at a high temperature. Conventional methods for preventing the warping phenomenon are not reliable due to the occurrence of hygroscopic phenomenon or decomposition at high temperature.

Accordingly, there is a need for an epoxy resin composition for sealing a semiconductor device that not only can prevent a warping phenomenon by improving the thermal expansion coefficient, but also minimizes the hygroscopic phenomenon and thus has high reliability.

An object of the present invention is to provide an epoxy resin composition for sealing a semiconductor element which has a high thermal expansion coefficient and can minimize a hygroscopic phenomenon and a semiconductor element sealed by using the composition.

It is another object of the present invention to provide an epoxy resin composition for sealing a semiconductor device with improved reliability as well as preventing a warping phenomenon and a semiconductor element sealed using the epoxy resin composition.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention relates to an epoxy resin composition for sealing a semiconductor device.

In one embodiment, the epoxy resin composition for encapsulating semiconductor devices is a composition comprising an epoxy resin, a curing agent, and a filler, wherein the filler comprises a meta-aramid having an aspect ratio of 10 to 200, wherein the meta- To 1% by weight.

The meta-aramid may include a repeating unit represented by the following formula (1), and n may have an average value of 100 to 1,000.

[Chemical Formula 1]

The meta-aramid may have a weight average molecular weight of 50,000 to 200,000.

The meta-aramid may have an average diameter of 0.1 탆 to 5 탆 and an average length of 50 탆 to 150 탆.

The epoxy resin composition may include 0.5 to 20% by weight of the epoxy resin, 0.1 to 13% by weight of the curing agent, and 70 to 98% by weight of the filler.

The epoxy resin composition may further include at least one of a curing accelerator, a coupling agent, a release agent, and a colorant.

Another aspect of the present invention relates to a semiconductor device.

In one embodiment, the semiconductor element may be sealed using the epoxy resin composition for sealing the semiconductor element.

The present invention provides an epoxy resin composition for sealing a semiconductor device, which has a high thermal expansion coefficient, can minimize a moisture absorption phenomenon, can prevent a warp phenomenon, and has improved reliability, and an effect of providing a sealed semiconductor element using the epoxy resin composition. .

Hereinafter, the present invention will be described in more detail.

In the following description of the present invention, detailed description of known related arts will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured by the present invention.

In the case where the word 'includes', 'having', 'done', etc. are used in this specification, other parts can be added unless '~ only' is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

Also, in interpreting the constituent elements, even if there is no separate description, it is interpreted as including the error range.

In the present specification, 'X to Y' representing the range means 'X or more and Y or less'.

The epoxy resin composition for encapsulating semiconductor devices according to one embodiment of the present invention is a composition comprising an epoxy resin, a curing agent, and a filler, wherein the filler comprises a meta-aramid having an aspect ratio of 10 to 200, By weight to 0.01% by weight to 1% by weight.

Hereinafter, each component of the epoxy resin composition of the present invention will be described in detail.

Epoxy resin

And is not particularly limited as long as it is an epoxy resin generally used for sealing semiconductor devices. In an embodiment, the epoxy resin may be an epoxy compound containing two or more epoxy groups in the molecule. Examples of the epoxy resin include an epoxy resin obtained by epoxidizing a condensate of phenol or alkyl phenol and hydroxybenzaldehyde, a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a multifunctional epoxy resin, a naphthol novolak Novolak type epoxy resins such as bisphenol A / bisphenol F / bisphenol AD, glycidyl ether of bisphenol A / bisphenol F / bisphenol AD, bishydroxybiphenyl type epoxy resin, dicyclopentadiene type epoxy resin, etc. . More specifically, the epoxy resin may be a phenol aralkyl type epoxy resin, a biphenyl type epoxy resin or a mixture thereof.

The phenol aralkyl type epoxy resin may be, for example, a phenol aralkyl type epoxy resin having a novolak structure including a biphenyl derivative represented by the following formula (2).

(2)

In Formula 2, the average value of b is 1 to 7.

The biphenyl type epoxy resin may be, for example, a biphenyl type epoxy resin represented by the following formula (3).

(3)

In formula (3), R ₈ , R ₉ , R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ and R ₁₅ are each independently an alkyl group having 1 to 4 carbon atoms, and the average value of c is 0 to 7.

In an embodiment, the epoxy resin may include at least one of a biphenyl type epoxy resin and a phenol aralkyl type epoxy resin. In an embodiment, the epoxy resin may include a biphenyl type epoxy resin and a phenol aralkyl type epoxy resin in a weight ratio of 0.5: 1 to 2: 1. In this case, it can be used together with the meta-aramid to improve the reliability of the semiconductor device.

The epoxy resin may be used in an amount of 0.5 to 20% by weight, specifically 3 to 15% by weight, more preferably 3 to 12% by weight, based on the epoxy resin composition for encapsulating semiconductor devices.

Hardener

As the curing agent, curing agents generally used for sealing semiconductor devices may be used without limitation, for example, a curing agent having two or more reactors may be used.

Specific examples of the curing agent include phenol aralkyl type phenol resin, phenol novolak type phenol resin, xylok type phenol resin, cresol novolak type phenol resin, naphthol type phenol resin, terpene type phenol resin, Phenolic resin, dicyclopentadiene-based phenol resin, novolak-type phenol resin synthesized from bisphenol A and resole, polyhydric phenol compound including tris (hydroxyphenyl) methane, dihydroxybiphenyl, maleic anhydride and phthalic anhydride, , Aromatic amines such as methanophenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone, but are not limited thereto.

For example, the curing agent may include at least one of a xylyl type phenol resin and a phenol aralkyl type phenol resin.

The phenol aralkyl type phenol resin may be, for example, a phenol aralkyl type phenol resin having a novolak structure including a biphenyl derivative in a molecule represented by the following general formula (4).

[Chemical Formula 4]

(In the formula (4), the average value of e is 1 to 7).

The phenol aralkyl type phenol resin represented by the above formula (4) reacts with an epoxy resin to form a carbon layer (char) to block the transfer of heat and oxygen to the surrounding, thereby achieving flame retardancy.

The xylo-type phenol resin may be, for example, a xylok-type phenol resin represented by the following general formula (5).

  [Chemical Formula 5]

(In Formula 5, the average value of f is 0 to 7)

The xylock type phenol resin represented by the above formula (5) can improve the fluidity and reliability of the resin composition.

In an embodiment, the curing agent may be a mixture of a phenol aralkyl type phenol resin and a xylock type phenol resin in a weight ratio of 0.5: 1 to 2: 1. In the above weight ratio range, when the meta-aramid is applied together, the thermal expansion coefficient can be further increased.

These curing agents may be used alone or in combination. Further, it can be used as an additional compound prepared by subjecting the above curing agent to a linear reaction such as an epoxy resin, a curing accelerator, a releasing agent, a coupling agent, a stress relieving agent and the like and a melt master batch.

The curing agent may be contained in an amount of 0.1 to 13% by weight, specifically 0.1 to 10% by weight, more specifically 0.1 to 8% by weight in the epoxy resin composition for sealing a semiconductor device.

The mixing ratio of the epoxy resin and the curing agent can be adjusted in accordance with the requirements of mechanical properties and moisture resistance reliability in the package. For example, the chemical equivalent ratio of the epoxy resin to the curing agent may be about 0.95 to about 3, specifically about 1 to about 2, more specifically about 1 to about 1.75. When the compounding ratio of the epoxy resin and the curing agent is in the above range, excellent strength can be realized after curing the epoxy resin composition.

Filler

The filler is intended to improve the mechanical properties of the epoxy resin composition and achieve low stress.

The present invention includes a meta-aramid having an aspect ratio of 10 to 200 as a filler. An epoxy resin composition comprising a meta-aramid having an aspect ratio of 10 to 200 has a high thermal expansion coefficient after curing and can minimize the hygroscopic phenomenon. Thereby, there is an advantage that not only the warping phenomenon of the semiconductor element can be prevented, but also the reliability is excellent. Where the aspect ratio means the ratio of the length to the diameter of the meta-aramid.

When the aspect ratio of the meta-aramid is less than 10, there is a problem that the fiber network formation rate is lowered or the effect of relieving stress is insufficient, and when the aspect ratio exceeds 200, the flow is lowered. In addition, the para-aramid has a lower heat resistance than the meta-aramid of the present invention, and thus has a problem of decomposition at high temperatures or inferiority of high-temperature reliability improvement.

The meta-aramid may have a repeating unit represented by the following formula (1), and the average value of n may be 100 to 1,000, specifically 200 to 850. Within this range, the meta-aramid can be uniformly dispersed in the epoxy resin composition.

[Chemical Formula 1]

The meta-aramid may have a weight average molecular weight of 50,000 to 200,000. Within this range, the meta-aramid is excellent in compatibility with other components in the epoxy resin composition.

The meta-aramid may have an average diameter of 0.1 탆 to 5 탆 and an average length of 50 탆 to 150 탆. There is an effect of improving the thermal expansion coefficient and preventing the hygroscopic phenomenon in the diameter and length range.

The meta-aramid is contained in an amount of 0.01 to 1% by weight, specifically 0.1 to 1% by weight in the epoxy resin composition for sealing a semiconductor device. When the epoxy resin composition contains more than 1% by weight of meta-aramid, the flow property of the epoxy resin composition is deteriorated.

Also, as fillers, they may include common fillers used in semiconductor encapsulants. Examples of the filler include fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, antimony oxide, have. These may be used alone or in combination.

As the filler, fused silica having a low linear expansion coefficient may be used for low stress. The fused silica refers to amorphous silica having a true specific gravity of 2.3 or less and includes amorphous silica obtained by melting crystalline silica or synthesized from various raw materials. Although the shape and the particle diameter of the fused silica are not particularly limited, the spherical fused silica having an average particle diameter of 5 to 30 탆 is contained in an amount of 50 to 99% by weight, the spherical fused silica having an average particle diameter of 0.001 to 1 탆 is contained in an amount of 1 to 50% To 40% by weight to 99.9% by weight based on the total filler. Further, the maximum particle diameter can be adjusted to any one of 45 탆, 55 탆 and 75 탆 according to the application. Since the spherical fused silica may contain conductive carbon as a foreign substance on the surface of the silica, it is also important to select a substance having a small amount of polar foreign substances.

The amount of the filler to be used varies depending on required properties such as moldability, low stress and high temperature strength. In embodiments, the filler may be included in the epoxy resin composition in an amount of 70 wt% to 98 wt%, specifically 70 wt% to 93 wt%, more specifically 70 wt% to 90 wt%. Within this range, there can be obtained an effect of ensuring the fluidity and reliability of the composition.

In an embodiment, the epoxy resin composition may include 0.5 to 20% by weight of the epoxy resin, 0.1 to 13% by weight of the curing agent, and 70 to 98% by weight of the filler.

In addition to the above components, the epoxy resin composition according to the present invention may further include at least one of a curing accelerator, a coupling agent, a release agent, and a colorant.

Hardening accelerator

The curing accelerator is a substance that promotes the reaction between the epoxy resin and the curing agent. As the curing accelerator, for example, a tertiary amine, an organometallic compound, an organic phosphorus compound, an imidazole, and a boron compound can be used. Tertiary amines include benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tri (dimethylaminomethyl) phenol, 2-2- (dimethylaminomethyl) phenol, 2,4,6-tris ) Phenol and tri-2-ethylhexyl acid salt.

Specific examples of the organometallic compound include chromium acetylacetonate, zinc acetylacetonate, nickel acetylacetonate, and the like. Organic phosphorus compounds include tris-4-methoxyphosphine, tetrabutylphosphonium bromide, tetraphenylphosphonium bromide, phenylphosphine, diphenylphosphine, triphenylphosphine, triphenylphosphine triphenylborane, triphenylphosphine Pin-1,4-benzoquinone adducts and the like. Imidazoles include, but are not limited to, 2-phenyl-4 methylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-aminoimidazole, -Methylimidazole, 2-heptadecylimidazole, and the like, but the present invention is not limited thereto. Specific examples of the boron compound include tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, tetraphenylboron salt, trifluoroborane-n-hexylamine, trifluoroborane monoethylamine, tetrafluoro Triethylamine, tetrafluoroborane amine, and the like. In addition, 1,5-diazabicyclo [4.3.0] non-5-ene (1,5-diazabicyclo [4.3.0] non-5-ene: DBN), 1,8-diazabicyclo [5.4. Diazabicyclo [5.4.0] undec-7-ene: DBU) and phenol novolac resin salt. However, the present invention is not limited thereto.

More specifically, organic phosphorus compounds, boron compounds, amine-based or imidazole-based curing accelerators may be used alone or in combination as the curing accelerator. As the curing accelerator, it is also possible to use an adduct made by reacting with an epoxy resin or a curing agent.

In the present invention, the amount of the curing accelerator to be used may be about 0.01 to about 2% by weight based on the total weight of the epoxy resin composition, specifically about 0.02 to 1.5% by weight, more specifically about 0.05 to 1% by weight . In the above range, the curing of the epoxy resin composition is promoted and the curing degree is also good.

Coupling agent

The coupling agent is for improving the interface strength by reacting between the epoxy resin and the filler, and may be, for example, a silane coupling agent. The silane coupling agent is not particularly limited as long as it reacts between the epoxy resin and the filler to improve the interface strength between the epoxy resin and the filler. Specific examples of the silane coupling agent include epoxy silane, aminosilane, ureido silane, mercaptosilane, and the like. The coupling agent may be used alone or in combination.

The coupling agent may be contained in an amount of about 0.01 wt% to 5 wt%, specifically about 0.05 wt% to 3 wt%, and more specifically about 0.1 wt% to 2 wt%, based on the total weight of the epoxy resin composition. The strength of the epoxy resin composition cured product is improved in the above range.

Release agent

As the release agent, at least one selected from the group consisting of paraffin wax, ester wax, higher fatty acid, higher fatty acid metal salt, natural fatty acid and natural fatty acid metal salt can be used.

The releasing agent may be contained in an amount of 0.1 to 1% by weight in the epoxy resin composition.

coloring agent

The coloring agent is for laser marking of a semiconductor element sealing material, and colorants well-known in the art can be used and are not particularly limited. For example, the colorant may include one or more of carbon black, titanium black, Nubian black, titanium nitride, dicopper hydroxide phosphate, iron oxide, mica.

The colorant may be contained in an amount of about 0.01% by weight to 5% by weight, specifically about 0.05% by weight to 3% by weight, and more specifically about 0.1% by weight to 2% by weight based on the total weight of the epoxy resin composition.

In addition, the epoxy resin composition of the present invention may contain a stress-relieving agent such as a modified silicone oil, a silicone powder, and a silicone resin to the extent that the object of the present invention is not impaired; And an antioxidant such as tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane.

The epoxy resin composition is prepared by uniformly mixing the above components uniformly at a predetermined mixing ratio using a Hensel mixer or Lodige mixer and then kneading the mixture in a roll mill or a kneader, , Followed by cooling and pulverization to obtain a final powder product.

The epoxy resin composition of the present invention can be usefully applied to semiconductor devices. As a method of sealing a semiconductor element using the epoxy resin composition obtained in the present invention, a low pressure transfer molding method can be generally used. However, molding can also be performed by injection molding, casting, compression molding or the like.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Example

The specifications of each component used in the following examples are as follows.

(A) an epoxy resin

(a1) Biphenyl type epoxy resin: YX-4000H product (epoxy equivalent 196) manufactured by Japan Epoxy Resin was used.

(a2) phenol aralkyl type epoxy resin: NC-3000 product (epoxy equivalent weight 270) manufactured by Nippon Kayaku was used.

(B) Curing agent

(b1) Phenol aralkyl type phenol resin: MEH-7851-SS product (hydroxyl equivalent 203) prepared in Meiwa was used.

(b2) Xylock type phenol resin: KPH-F3065 manufactured by Kolon (hydroxyl equivalent 203) was used.

(C) filler

(c1) Meta-aramid: An ARAWIN product (average diameter 2 m, average length 120 m, aspect ratio 60, weight average molecular weight 80,000) manufactured by Toray Chemical Co., Ltd. was used.

(c2) siloxane particles tospearl 2000b of Momnetive Co., Ltd. spherical powder having an average diameter of 7 mu m

(c3) 9: 1 (by weight) mixture of spherical fused silica having an average particle diameter of 18 탆 and spherical fused silica having an average particle diameter of 0.5 탆

(D) Curing accelerator: 2-phenyl-4-methylimidazole (2P4MHZ) manufactured by Shikoku Chemicals was used.

(E) Coupling agent: Epoxysilane (A-187) manufactured by CHISSO was used.

(F) Colorant

(f1) Carbon black: MA-600B manufactured by Mitsubishi Chemical was used.

(f2) Black dye: Nubian Black TH-807 manufactured by Orient Chemical (pH 7.0) was used.

(G) Release agent: Carnauba wax was used.

Example  1 to 4 and Comparative Example  1 to 2

Each of the above components was weighed according to the composition shown in the following Table 1, and then uniformly mixed using a Henschel mixer to prepare a powdery primary composition. Thereafter, the mixture was melt kneaded at 120 DEG C for 30 minutes using a continuous kneader, cooled to 10 to 15 DEG C and pulverized to prepare an epoxy resin composition for sealing semiconductor devices.

(unit:
weight%) Example Comparative Example One 2 3 4 One 2 (A) (a1) 1.79 1.79 1.79 1.79 1.79 1.79 (a2) 1.80 1.80 1.80 1.80 1.80 1.80 (B) (b1) 0.97 0.97 0.97 0.97 0.97 0.97 (b2) 0.97 0.97 0.97 0.97 0.97 0.97 (C) (c1) 0.01 0.1 0.5 One - - (c2) - - - - - 0.5 (c3) 92.99 92.9 92.5 92.0 93.0 92.5 (D) 0.07 0.07 0.07 0.07 0.07 0.07 (E) 0.40 0.40 0.40 0.40 0.40 0.40 (F) (f1) 0.20 0.20 0.20 0.20 0.20 0.20 (f2) 0.10 0.10 0.10 0.10 0.10 0.10 (G) 0.70 0.70 0.70 0.70 0.70 0.70 Sum 100 100 100 100 100 100

The epoxy resin composition for sealing semiconductor devices prepared above was evaluated for physical properties by the following methods, and the results are shown in Table 2 below.

Property evaluation method

(1) Spiral flow (inch): A mold for spiral flow measurement according to EMMI-1-66 was molded using a low pressure transfer molding machine under the conditions of a mold temperature of 175 캜, 70 kgf / cm ² , an injection pressure of 9 MPa and a curing time of 90 seconds The epoxy resin composition was injected and the flow length was measured. The higher the measured value, the better the fluidity.

(2) Coefficient of thermal expansion (? 1, 占 퐉 / m 占 폚): Evaluated according to ASTM D696.

(3) Moisture absorptivity (wt%): A standard specimen was prepared in accordance with ASTM D792 and then post-cured in an oven (Oven, JEIO TECH) at 175 ° C for 4 hours using PCT (Pressure Cooker Tester) Humidity, 100% RH for 24 hours, and the moisture absorption rate was measured at 25 deg. C through the moisture absorption amount before and after moisture absorption.

(4) Reliability: A dummy chip was molded in an epoxy resin composition at 175 ° C on a PCB to obtain a specimen. The obtained specimens were post-cured (PMC) at 175 ° C for 4 hours. Thereafter, IR reflow was carried out according to the following individual conditions after standing for 6 hours at 121 ° C, 100% RH and 2 atm under PCT (pressure cooker test) conditions. After the IR reflow process was completed for all five conditions, the specimens were examined for image peeling using an ultrasonic analysis SAT (Scanning Acoustic Tomography) facility. The reliability was evaluated by the lowest temperature at which peeling occurred (IR reflow Max temperature for each condition).

Condition 0: 270 to 275 ° C, Max 270 ° C Condition 1: 275 to 280 ° C, Max 275 ° C Condition 2: 280 to 285 DEG C, Max 278 DEG C Condition 3: 285 to 290 ° C, Max 293 ° C Condition 4: 290 to 295 DEG C, Max 298 DEG C

Example Comparative Example One 2 3 4 One 2 Spiral flow (inch) 45 44 41 36 45 40 Coefficient of thermal expansion
(? 1, 占 퐉 / m 占 폚) 13 14 16 17 12 14 Moisture absorption rate (wt%) 0.3 0.3 0.3 0.3 0.3 0.45 responsibility 278 ° C 278 ° C 298 ° C 293 ° C 270 ℃ 275 ° C

As shown in Table 3, it can be seen that the embodiment including the meta-aramid having a specific aspect ratio of the present invention has a high thermal expansion coefficient, low moisture absorption rate, prevents warping, and high reliability. On the other hand, Comparative Example 1, which does not include the meta-aramid of the present invention, has a low coefficient of thermal expansion and reliability, and Comparative Example 2 in which an organic filler of silicone material is used instead of meta-aramid has a high hygroscopicity and low reliability.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are in all respects illustrative and not restrictive.

Claims (6)

An epoxy resin, a curing agent, and a filler,
Wherein the filler comprises a meta-aramid having an aspect ratio of 10 to 200,
Wherein the meta-aramid is contained in the composition in an amount of 0.01 to 1% by weight.
The epoxy resin composition for sealing a semiconductor device according to claim 1, wherein the meta-aramid comprises a repeating unit represented by the following formula (1) and an average value of n is 100 to 1,000:
[Chemical Formula 1]

.
The method according to claim 1,
Wherein the meta-aramid has an average diameter of 0.1 to 5 占 퐉 and an average length of 50 to 150 占 퐉.
The epoxy resin composition according to claim 1,
0.5 to 20% by weight of the epoxy resin,
0.1% to 13% by weight of the curing agent, and
And 70% by weight to 98% by weight of the filler.
The epoxy resin composition for sealing a semiconductor device according to claim 1, wherein the epoxy resin composition further comprises at least one of a curing accelerator, a coupling agent, a releasing agent and a colorant.
A semiconductor device encapsulated with an epoxy resin composition for encapsulating semiconductor devices according to any one of claims 1 to 5.