KR100898335B1 - Epoxy resin composition for encapsulating semiconductor device and semiconductor device using the same - Google Patents

Abstract

The present invention relates to an epoxy resin composition for sealing a semiconductor device and a semiconductor device sealed using the same, and more particularly, to an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and an additive. By using a polyethylene wax and an antioxidant, a semiconductor device having excellent releasability, continuous workability, and reliability is provided.

Semiconductor devices, additives, polyethylene wax, antioxidants, release properties, continuous workability, reliability

Description

Epoxy resin composition for encapsulating semiconductor device and semiconductor device using the same

The present invention relates to an epoxy resin composition for sealing a semiconductor device, and more particularly, an epoxy resin composition for sealing a semiconductor device excellent in mold release property between a package and a mold after molding, contamination resistance of the package surface and the mold, continuous workability, and package reliability; It relates to a semiconductor device sealed using this.

The technology of the degree of integration of semiconductor devices is improving, and accordingly, the miniaturization of wiring, the enlargement of chips, and the multilayer wiring are rapidly progressing. On the other hand, a package that protects a semiconductor element from the external environment is accelerating its size and thickness from the viewpoint of high-density mounting on a printed board, that is, surface mounting.

In general, when releasing from a mold after semiconductor package molding, if sufficient release property is not secured, the possibility of package cracking increases. This problem occurs more frequently as the semiconductor package becomes thinner.

Usually, as a method of reducing the stress at the time of mold release, the method of mixing various types of wax in an epoxy resin composition is widely adopted. In this method, the wax must continuously maintain the heat resistance even at a high temperature during packaging. Existing wax-mixed products show a phenomenon in which the release performance deteriorates with time due to lack of high temperature heat resistance. In order to improve such a problem, increasing the content of the entire wax decreases the adhesion between the semiconductor chip and the lead frame and the epoxy resin composition, which may cause a problem in package reliability, and also accumulate oxidized wax in the mold, thereby improving continuous workability. There was a problem that the phenomena occurred and contamination on the surface of the semiconductor package.

The present invention is to solve the problems of the prior art as described above, and an object of the present invention is to provide an epoxy resin composition for sealing a semiconductor device excellent in releasability, continuous workability and reliability, and a semiconductor device using the same.

Therefore, according to the present invention, in the epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and an additive, a polyethylene wax represented by the following formula (1) and an antioxidant represented by the following formula (2) are used as the additive. An epoxy resin composition for semiconductor element sealing is provided.

[Formula 1]

(Wherein n is an integer from 30 to 450).

[Formula 2]

(Wherein R 1 and R 2 are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms.)

The polyethylene wax of the formula (1) is characterized in that the viscosity at 120 ° C is 300 mPa · s or less, and the number average molecular weight is 1000 to 3000.

The antioxidant of Formula 2 is characterized in that the molecular weight is 500 ~ 800.

The polyethylene wax of Chemical Formula 1 and the antioxidant of Chemical Formula 2 may be used after mixing by melt blending before use.

A mixture ratio of the polyethylene wax of Formula 1 and the antioxidant of Formula 2 is 2: 1 to 8: 1.

The total content of the polyethylene wax of Formula 1 and the antioxidant of Formula 2 is 0.001 to 4% by weight based on the total epoxy resin composition.

In another aspect, the present invention provides a semiconductor device that is mixed with the epoxy resin composition using a Henschel mixer or a Lodige mixer, melt kneaded with a roll mill or kneader, and then sealed with a final powder product obtained through cooling and grinding. do.

The final powder product is sealed by a low pressure transfer molding method, an injection molding method or a casting (Casting) molding method.

The semiconductor device may include a lead frame selected from a copper lead frame, an iron lead frame, a lead frame pre-plated with a material containing nickel and palladium in a copper or iron lead frame, and an organic laminate frame.

The epoxy resin composition for semiconductor element sealing of the present invention is useful for producing a semiconductor element having excellent releasability, continuous workability, and reliability.

The present invention is an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and an additive, wherein the additive is a polyethylene wax represented by the following formula (1) and an antioxidant represented by the following formula (2). Provided are an epoxy resin composition for sealing a semiconductor element and a semiconductor element using the same.

[Formula 1]

(Wherein n is an integer from 30 to 450).

[Formula 2]

(Wherein R 1 and R 2 are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms.)

The polyethylene wax represented by Chemical Formula 1 is a release agent, and the antioxidant represented by Chemical Formula 2 has an effect of preventing long term thermal stability at high temperature by preventing oxidation of the release agent. The polyethylene wax of the formula (1) is preferably a viscosity of 120 mPa · s or less, the number average molecular weight of 1000 to 3000, the antioxidant of the formula (2) of 500 to 800 It is desirable to.

In order to maximize the effect of the antioxidant, the polyethylene wax of Formula 1 and the antioxidant of Formula 2 are preferably used after melt blending before use, wherein the mixing ratio is preferably 2: 1 to 8: 1. , 3: 1 to 7: 1 are more preferred, and 4: 1 to 6: 1. In addition to the polyethylene wax of Formula 1, other release agents such as higher fatty acids, higher fatty acid metal salts, natural fatty acids, paraffin waxes, and ester waxes may be used together before or after the melt blending. In addition, in order to uniformly disperse the release agent and the antioxidant in the epoxy resin composition, before dissolving and dispersing it in the melt of the epoxy resin or curing agent in advance through a method such as melt master batch (MMB) It may be added to the composition and may be used by spraying at the time of mixing the raw materials of the epoxy resin composition.

The polyethylene wax of Chemical Formula 1 and the antioxidant of Chemical Formula 2 may be used in an amount of 0.001 to 4 wt% based on the total epoxy resin composition in terms of releasability between the package and the mold after molding, contamination of the package surface and the mold, and package reliability. It is preferable to use it in 0.01 to 3 weight%, and it is more preferable to use it in 0.1 to 2 weight%.

The epoxy resin of the present invention is not particularly limited as long as it is an epoxy resin generally used for semiconductor sealing, and is preferably an epoxy compound containing two or more epoxy groups in a molecule. Such epoxy resins include epoxy resins obtained by epoxidizing condensates of phenol or alkyl phenols with hydroxybenzaldehyde, phenol novolak type epoxy resins, cresol novolak type epoxy resins, polyfunctional epoxy resins, and biphenyl type epoxy resins. , Phenol aralkyl type epoxy resin, naphthol novolak type epoxy resin, bisphenol A / bisphenol F / bisphenol AD novolak type epoxy resin, bisphenol A / bisphenol F / bisphenol AD glycidyl ether, bishydroxy biphenyl epoxy Resins, dicyclopentadiene-based epoxy resins, and the like. Preferred epoxy resins include polyfunctional epoxy resins, biphenyl epoxy resins, and phenol aralkyl type epoxy resins having a novolak structure containing a biphenyl derivative in a molecule. These epoxy resins may be used alone or in combination, and additional compounds made by preliminary reactions such as melt master batches with other components, such as curing agents, curing accelerators, reaction regulators, mold release agents, coupling agents, and stress relaxers, may also be used. have. In addition, it is preferable to use those having low chlorine ions, sodium ions, and other ionic impurities contained in such epoxy resins to improve the moisture resistance reliability. 2-15 weight% is preferable with respect to the whole epoxy resin composition, and, as for the usage-amount, 3-12 weight% is more preferable.

The curing agent of the present invention is generally used for semiconductor sealing and is not particularly limited as long as it has two or more reactors. Specifically, a phenol aralkyl type phenol resin, a phenol novolak type phenol resin, a xylock type phenol resin, and a cresol novolak type Phenolic resin, naphthol phenol resin, terpene phenol resin, polyfunctional phenol resin, dicyclopentadiene phenol resin, novolac phenol resin synthesized from bisphenol A and resol, tris (hydroxyphenyl) methane, dihydroxy And polyhydric phenol compounds containing biphenyl, acid anhydrides containing maleic anhydride and phthalic anhydride, aromatic amines such as metaphenylenediamine, diaminoimphenylmethane, diaminoimphenylsulfone, and the like. Preferred curing agents of these are polyfunctional phenol resins. These curing agents may be used alone or in combination, and may also be used as additive compounds made by preliminary reactions such as melt master batches with other components such as epoxy resins, curing accelerators, reaction control agents, mold release agents, coupling agents, stress relief agents and the like. have. 0.5-12 weight% is preferable with respect to the total epoxy resin composition, and, as for the usage-amount, 1-8 weight% is more preferable. The compounding ratio of the epoxy resin and the curing agent is preferably a chemical equivalent ratio of the epoxy resin to the curing agent is 0.5 to 2, more preferably 0.8 to 1.6, depending on the mechanical properties and moisture resistance reliability of the package.

The curing accelerator used in the present invention is a substance that promotes the reaction between the epoxy resin and the curing agent. For example, tertiary amines, organometallic compounds, organophosphorus compounds, imidazoles, boron compounds and the like can be used. Tertiary amines include benzyldimethylamine, triethanolamine, triethylenediamine, diethylaminoethanol, tri (dimethylaminomethyl) phenol, 2-2- (dimethylaminomethyl) phenol, 2,4,6-tris (dia) Salts of minomethyl) phenol and tri-2-ethylhexyl acid, and the like. Organometallic compounds include chromium acetylacetonate, zinc acetylacetonate, nickel acetylacetonate and the like. Organophosphorus compounds include tris-4-methoxyphosphine, tetrabutylphosphonium bromide, butyltriphenylphosphonium bromide, phenylphosphine, diphenylphosphine, triphenylphosphine, triphenylphosphine triphenylborane, triphenyl Phosphine-1,4-benzoquinone adducts and the like. The imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-aminoimidazole, 2methyl-1-vinylimidazole, 2-ethyl-4-methylimidazole, and 2-heptadecyl. Midazoles and the like. Boron compounds include tetraphenylphosphonium-tetraphenylborate, triphenylphosphine tetraphenylborate, tetraphenylboron salt, trifluoroborane-n-hexylamine, trifluoroborane monoethylamine, tetrafluoroboranetriethylamine And tetrafluoroboraneamine. 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 .0] undec-7-ene (1,8-diazabicyclo [5.4.0] undec-7-ene: DBU), phenol novolak resin salts, and the like. Particularly preferred curing accelerators include organophosphorus compounds, amine-based or imidazole-based curing accelerators used alone or in combination. The curing accelerator may use an epoxy resin or an adduct made by linear reaction with a curing agent. As for the compounding quantity of the hardening accelerator used by this invention, 0.001-1.5 weight% is preferable with respect to the whole epoxy resin composition, and 0.01-1 weight% is more preferable.

The inorganic filler used in the present invention is a material used for improving the mechanical properties of the epoxy resin composition and reducing the stress. Examples generally used include fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, antimony oxide, glass fibers and the like. In order to reduce the stress, it is preferable to use molten silica having a low linear window coefficient. The fused silica refers to amorphous silica having a specific gravity of 2.3 or less, and includes crystalline silica made by melting crystalline silica or synthesized from various raw materials. The shape and particle size of the molten silica are not particularly limited, but the molten silica includes 50 to 99% by weight of spherical molten silica having an average particle diameter of 5 to 30 µm and 1 to 50% by weight of spherical molten silica having an average particle diameter of 0.001 to 1 µm. It is preferred to include the mixture in an amount of 40 to 100% by weight based on the total filler. Moreover, according to a use, the maximum particle diameter can be adjusted to 45um, 55um, 75um, etc., and can be used. In fused spherical silica, conductive carbon may be included as a foreign material on the silica surface, but it is also important to select a material with little foreign matter mixing. In the present invention, the ratio of the inorganic filler depends on the required physical properties such as moldability, low stress, high temperature strength, etc., but is preferably used in an amount of 70 to 95% by weight based on the total epoxy resin composition, It is more preferable to use.

In addition, the epoxy resin composition of the present invention is a coupling agent such as coloring agents such as carbon black, organic dyes, inorganic dyes, epoxysilanes, aminosilanes, mercaptosilanes, alkylsilanes, alkoxysilanes and the like in a range that does not impair the object of the present invention Stress relieving agents, such as silicone oil, silicone powder, and silicone resin, etc. can be contained as needed. At this time, the modified silicone oil is preferably a silicone polymer excellent in heat resistance, a silicone oil having an epoxy functional group, a silicone oil having an amine functional group, a silicone oil having a carboxyl functional group, or the like, or a mixture of two or more kinds thereof to the entire epoxy resin composition. It can be used in 0.01 to 2% by weight relative to the. Moreover, oil and inorganic flame retardants, such as phosphazene, zinc borate, aluminum hydroxide, and magnesium hydroxide, can be contained as needed.

As a general method for producing an epoxy resin composition using the raw materials described above, a predetermined amount is uniformly mixed sufficiently using a Henschel mixer or a Roedig mixer, melt-kneaded with a roll mill or kneader, and then cooled and pulverized. The process of obtaining the final powder product is used. As a method of sealing a semiconductor element using the epoxy resin composition obtained in the present invention, the low pressure transfer molding method is most commonly used, and molding can also be carried out by a method such as injection molding or casting. By the above method, a semiconductor device of a copper lead frame or an iron lead frame or a lead frame pre-plated with a material containing nickel and palladium on the lead frame or an organic laminate frame can be manufactured.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

[Example 1 or 2, Comparative Example 1 or 2]

Next, after mixing uniformly using a Henschel mixer according to the composition of Table 1, melt kneading in a range of 100 to 120 ° C. using a twin screw kneader, and cooling and pulverizing the epoxy resin composition for semiconductor sealing. Prepared. Various physical properties were evaluated by the following method. The evaluation results are shown in Table 1.

(Releasing force): The epoxy resin composition prepared as described above was cleaned after cleaning the mold release force test mold shown in FIG. 1 by three transfer moldings for 300 seconds at 175 ° C using melamine resin. After transfer molding to the mold under the conditions, the release force with the mold was measured through a measuring device having a force pull gauge as shown in FIG.

The release force was measured 40 times for each resin composition, and the results are shown in Table 1 and FIG. 3. The lower the measured value, the better the release force.

(Continuous workability): The epoxy resin composition of Table 1 was molded for 60 seconds at 175 ° C and transfer pressure of 9.3 MPa using an MPS (Multi Plunger System) molding machine to form a 208-LQFP (Low-profile Quad Flat Package) (28mm × 28 mm x 1.4 mm) package was produced continuously. The number of continuous moldings until release defects such as gate clogging, air vent clogging, package tearing, and curl tearing occurred was evaluated. The higher the number of continuous moldings, the better the continuous workability.

(Reliability): In the continuous workability evaluation, 36 initially prepared 208-LQFP packages were post-cured (PMC) for 4 hours at 175 ° C and then cooled to room temperature. After drying the package at 125 ° C. for 24 hours, a thermal shock test of 5 cycles (1 cycle means 10 minutes at −65 ° C., 5 minutes at 25 ° C. and 10 minutes at 150 ° C.) was performed. It was. Then, the package was left at 85 ° C. and 85% relative humidity condition for 168 hours, and then the C non-destructive tester after preconditioning condition of repeating three passes of IR reflow for 30 seconds at 260 ° C. Scanning Acoustical Microscopy (SAM) was used to evaluate the occurrence of delamination between the package crack and the epoxy resin composition and the leadframe.

(Unit: weight%)

Note 1) EPPN-502H, Nippon Kayaku

   2) YX-4000H, JER

   3) NC-3000, Nippon Kayaku

   4) MEH-7500, Meiwa Chem.

   5) TPP-K, Hokko

   6) FB-100, Denka

   7) KMP-594, Shinetsu

8) PED-522, Clariant

   9) 5: 1 melt mixture of wax (PED-522; Clariant) and antioxidant (SONGNOX 2450; Songwon Industry)

   10) S-510, Chisso

   11) KBM-573, Shinetsu

   12) MA-600, Matsushita

   From the above results, it was confirmed that the epoxy resin composition according to the present invention can produce a semiconductor device having excellent releasability, continuous workability, and reliability.

1 is a view showing a release force test mold used in the embodiment of the present invention,

2 is a view showing a release force measuring apparatus used in an embodiment of the present invention, and

3 is a graph comparing the release force measured using the resin compositions of Examples and Comparative Examples of the present invention.

Claims (9)

An epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, and an additive, wherein the additive comprises a polyethylene wax represented by the following formula (1) and an antioxidant represented by the following formula (2). Epoxy resin composition for element sealing. [Formula 1]

(Wherein n is an integer from 30 to 450). [Formula 2]

(Wherein R 1 and R 2 are each independently hydrogen or an alkyl group having 1 to 12 carbon atoms.) The epoxy resin composition for sealing a semiconductor device according to claim 1, wherein the polyethylene wax of Chemical Formula 1 has a viscosity at 120 ° C of 300 mPa · s or less and a number average molecular weight of 1000 to 3000. The epoxy resin composition of claim 1, wherein the antioxidant of Formula 2 has a molecular weight of 500 to 800. The epoxy resin composition of claim 1, wherein the polyethylene wax of Formula 1 and the antioxidant of Formula 2 are used after melt blending before use. The epoxy resin composition for sealing a semiconductor device according to claim 4, wherein a mixing ratio of the polyethylene wax of Chemical Formula 1 and the antioxidant of Chemical Formula 2 is 2: 1 to 8: 1. The epoxy resin composition for sealing a semiconductor device according to claim 1, wherein the total content of the polyethylene wax of Formula 1 and the antioxidant of Formula 2 is 0.001 to 4 wt% based on the total epoxy resin composition. The epoxy resin composition for sealing a semiconductor element according to any one of claims 1 to 6 is mixed using a Henschel mixer or a Lodige mixer, melt-kneaded with a roll mill or kneader, and then cooled and pulverized. A semiconductor device sealed with the final powder product obtained. 8. The semiconductor device according to claim 7, wherein the final powder product is sealed by low pressure transfer molding, injection molding, or casting molding. The semiconductor device of claim 8, wherein the semiconductor device comprises a lead frame selected from a copper lead frame, an iron lead frame, a lead frame pre-plated with a material containing nickel and palladium in a copper or iron lead frame, and an organic laminate frame. A semiconductor device characterized in that.

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