KR100882332B1 - Epoxy resin composition for encapsulating semiconductor device and semiconductor device using the same - Google Patents

Abstract

An epoxy resin composition for encapsulating a semiconductor device is provided to ensure excellent flame retardancy without the use of a halogen-based flame retardant, good moldability in the semiconductor device packaging and excellent bending property and reliability of package. An epoxy resin composition for encapsulating a semiconductor device comprises epoxy resin, curing agent, curing accelerator and inorganic filler. The curing agent is a biphenyl-containing modified phenol novolac type phenol resin indicated as the chemical formula 1. In the chemical formula 1, the average of m and n is respectively 1-10. The order of two repeating units can be arranged in the chemical formula 1 randomly.

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 a semiconductor device using the same, and more particularly, to an epoxy resin composition for sealing a semiconductor device excellent in bending property, moldability, reliability, and flame retardant properties of a package and sealing using the same. It relates to a semiconductor device.

In general, in semiconductor sealing epoxy resin compositions, all semiconductor companies require a flame retardant grade of UL-94 V-0. In order to secure the flame retardant grade, conventionally, halogenated epoxy resin was used as a main flame retardant, and antimony trioxide was used as a secondary flame retardant to secure flame retardancy. However, antimony trioxide is a carcinogenic substance, which is very harmful to the human body. Also, in the case of an epoxy resin composition for sealing a semiconductor using a halogen-based flame retardant, toxic carcinogens such as dioxin or difuran are generated during incineration or fire. In addition, the ozone layer is destroyed by gases such as HBr and HCl generated during combustion, and has a fatal effect on the environment. Phosphorus flame retardants such as phosphazene and phosphate esters have been studied as a countermeasure. However, in the case of phosphorus flame retardants, phosphoric acid and polyphosphoric acid formed by bonding with water have a problem of deteriorating reliability of semiconductors. In addition, since the metal oxide or the hydroxide has a poor flame retardant effect, a large amount is used, and thus, it is difficult to secure fluidity and formability during semiconductor packaging.

As a countermeasure, organic phosphorus flame retardants such as phosphazene and phosphate esters, inorganic functional flame retardants such as aluminum hydroxide, magnesium hydroxide and talc, and novel flame retardants such as nitrogen-containing resins have been considered. Phosphoric acid and polyphosphoric acid produced by combining with water have a problem of deteriorating the reliability of semiconductors, and moisture absorption of semiconductor packages has been increased in the case of inorganic functional flame retardants, and some self-extinguishing flame retardant properties of nitrogen element-containing resins However, there was a problem that the flame retardant effect is insufficient to satisfy the flame retardant standard required by the semiconductor company.

In addition, the surface-mounted BGA (Ball Grid Array) type package, which has recently attracted attention, has a problem in that package warpage is likely to occur due to asymmetry of thermal expansion shrinkage due to a single-sided packaging structure. Similarly, new types of packages such as board on chip (BOC), multi chip package (MCP) and mirco land grid array (uLGA) packages not only cause the warpage problem, but also the thickness of the resin composition is thinner to 100 microns. Due to this, molding defects such as pores or incomplete molding occur frequently during package sealing. In addition, due to the recent increase in environmental concern, a solderless welding method has been applied in the process of mounting a semiconductor package. Most of the welding available in the semiconductor package field has a higher melting point than that of a conventional solder containing ripple. The reflow temperature is very high. This causes a problem that the reliability of the package is deteriorated and it is required to improve the reflow-resistant property that can prevent this.

The present invention is to solve the above problems, an object of the present invention is to exhibit excellent flame retardancy without using a halogen-based flame retardant, excellent moldability in packaging a semiconductor device, the bending characteristics of the package after fabrication of the semiconductor device An epoxy resin composition with good reliability and a semiconductor device sealed using the same are provided.

Therefore, according to the present invention, in the epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler, a biphenyl-containing modified phenol novolac type phenol resin represented by the following formula (1) is used as the curing agent. An epoxy resin composition for sealing semiconductor elements is provided.

[Formula 1]

(In the above formula, the average value of m and n are 1 to 10, respectively, and the order of the two repeating units may be randomly arranged in Formula 1.)

The hydroxyl equivalent of the biphenyl-containing modified phenol novolak-type phenolic resin is 100 to 400, characterized in that the softening point is 40 to 120 ℃.

The biphenyl-containing modified phenol novolak-type phenolic resin is characterized in that 5 to 100% by weight based on the total curing agent.

It is characterized by using together with the said biphenyl-containing modified phenol novolak-type phenol resin which the xylolic phenol resin represented by General formula (2) or the polyfunctional type phenol resin represented by following General formula (3) as said hardening | curing agent.

[Formula 2]

(In the above formula, the average value of n is 0 to 7.)

[Formula 3]

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

The epoxy resin is characterized by using a biphenyl type epoxy resin represented by the following formula (4) or a biphenyl-containing modified novolak type epoxy resin represented by the following formula (5).

[Formula 4]

(In the above formula, the average value of n is 0 to 7.)

[Formula 5]

(In the above formula, the average value of m and n are 1 to 10, respectively, and the order of the two repeating units may be randomly arranged in Formula 5.)

Epoxy equivalent of the biphenyl-containing modified novolak-type epoxy resin is 100 to 400, characterized in that the softening point is 40 to 80 ℃.

3 to 20 wt% of spherical molten silica having an average particle diameter of 0.1 to 3 µm, 5 to 30 wt% of spherical molten silica having an average particle diameter of 3 to 10 µm, and 50 spherical molten silica having an average particle diameter of 10 to 25 µm. It characterized in that it comprises a molten silica mixture including ~ 92% by weight to 40 to 100% by weight relative to the total inorganic filler.

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 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 present invention is useful for fabricating semiconductor devices having excellent flame retardancy and warpage characteristics, and excellent moldability and reliability.

In the epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler, a semiconductor comprising a biphenyl-containing modified phenol novolac-type phenol resin represented by the following formula (1) as the curing agent: An epoxy resin composition for sealing an element and a semiconductor device using the same are provided.

[Formula 1]

(In the above formula, the average value of m and n are 1 to 10, respectively, and the order of the two repeating units may be randomly arranged in Formula 1.)

The biphenyl-containing modified phenol novolac-type phenolic resin of Formula 1 exhibits a flame retardant effect in itself, and is an effective resin for package bending property. It is preferable that the said biphenyl containing modified phenol novolak-type phenol resin has a hydroxyl equivalent of 100-400, and a softening point is 40-120 degreeC. In view of flame retardancy, warpage characteristics of the package and fluidity of the resin composition, the biphenyl-containing modified phenol novolac-type phenol resin is preferably used in an amount of 5 to 100% by weight based on the total curing agent, and is used in an amount of 10 to 95% by weight. More preferably, it is most preferably used at 15 to 90% by weight.

In the present invention, the curing agent that can be used in combination with the biphenyl-containing modified phenol novolak-type phenol resin is generally used for semiconductor sealing and is not particularly limited as long as it has two or more reactors, and specifically, a phenol aralkyl type Phenol resin, phenol novolak phenol resin, xylok phenol resin, cresol novolak phenol resin, naphthol phenol resin, terpene phenol resin, polyfunctional phenol resin, dicyclopentadiene phenol resin, Novolac-type phenolic resins synthesized from bisphenol A and resol, polyhydric phenol compounds including tris (hydroxyphenyl) methane, dihydroxybiphenyl, acid anhydrides including maleic anhydride and phthalic anhydride, metaphenylenediamine, dia Aromatic amines, such as a minoy phenylmethane and diamino diphenyl sulfone, etc. are mentioned. Among these, a particularly preferable curing agent includes a xylock type phenol resin represented by the following formula (2) or a polyfunctional type phenol resin represented by the following formula (3). These curing agents including the biphenyl-containing modified phenol novolak-type phenolic resins may be used alone or in combination, and other components such as epoxy resins, curing accelerators, reaction regulators, mold release agents, coupling agents, stress relaxation agents, and melt masters in the curing agent. It can also be used as an additive compound made by pre-reaction such as melt master batch 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.

[Formula 2]

(In the above formula, the average value of n is 0 to 7.)

[Formula 3]

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

Xyloxy phenolic resin of the formula (2) is preferred in terms of enhancing the fluidity and reliability of the resin composition, polyfunctional phenolic resin of the formula (3) is preferred in terms of improving the bending characteristics.

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 novolac epoxy resins, cresol novolac epoxy resins, biphenyl epoxy resins, and phenol aralkyl types. Epoxy resin, polyfunctional epoxy resin, naphthol novolac epoxy resin, novolak epoxy resin of bisphenol A / bisphenol F / bisphenol AD, glycidyl ether of bisphenol A / bisphenol F / bisphenol AD, bishydroxy biphenyl type Epoxy resin, dicyclopentadiene type epoxy resin, etc. are mentioned. Particularly preferred epoxy resins include biphenyl epoxy resins represented by the following general formula (4) or biphenyl-containing modified novolac epoxy resins represented by the following general formula (5). These epoxy resins may be used alone or in combination, and are made by preliminary reaction such as a melt master batch with other components such as a curing agent, a curing accelerator, a reaction regulator, a releasing agent, a coupling agent, a stress relaxation agent, and the like. Additional compounds can also be used. 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.

[Formula 4]

(In the above formula, the average value of n is 0 to 7.)

[Formula 5]

(In the above formula, the average value of m and n are 1 to 10, respectively, and the order of the two repeating units may be randomly arranged in Formula 5.)

The biphenyl type epoxy resin of Chemical Formula 4 is preferable in view of fluidity and package reliability of the resin composition, and the biphenyl-containing modified novolac epoxy resin of Chemical Formula 5 exhibits a flame retardant effect in itself, and is effective in package bending characteristics. to be. It is preferable that the said biphenyl containing modified novolak-type epoxy resin has an epoxy equivalent of 100-400, and a softening point of 40-80 degreeC.

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 (diamino Salts of methyl) 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) and phenol novolak resin salts may be used. 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 diameter of the molten silica are not particularly limited, but 3 to 20% by weight of spherical molten silica having an average particle diameter of 0.1 to 3 µm, 5 to 30% by weight of spherical molten silica having an average particle diameter of 3 to 10 µm and an average particle diameter of 10 It is preferable to include a molten silica mixture containing 50 to 92% by weight of spherical molten silica of ˜25 μm to 40 to 100% by weight relative to the total inorganic filler. Moreover, it can also be used, adjusting the maximum particle diameter to 45um, 55um, 75um, etc. according to a use. 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 72 to 95% by weight based on the total epoxy resin composition, and the ratio of 80 to 93% by weight. It is more preferable to use.

In addition, the epoxy resin composition of the present invention is a release agent such as higher fatty acids, higher fatty acid metal salts, ester waxes, coloring agents such as carbon black, organic dyes, inorganic dyes, epoxy silanes, amino silanes, etc. without departing from the object of the present invention. Coupling agents, such as mercaptosilane, alkylsilane, and alkoxysilane, and stress relaxation agents, such as modified 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.

[Examples 1 to 3, Comparative Example 1 or 2]

Next, the mixture was uniformly mixed using a Henschel mixer according to the composition of Table 1, and then melt-kneaded in a range of 100 to 120 ° C. using a continuous kneader, followed by cooling and grinding to prepare an epoxy resin composition for semiconductor sealing. Various physical properties were evaluated by the following method. The evaluation results are shown in Table 2.

(Fluidity / spiral flow): The flow length was measured using a transfer molding press at 175 ° C. and 70 Kgf / cm 2 using an evaluation mold in accordance with EMMI-1-66. The higher the measured value, the better the fluidity.

(Glass Transition Temperature (Tg)): Evaluated by TMA (Thermomechanical Analyzer).

(Bending Strength and Flexural Modulus): Standard specimens (125 × 12.6 × 6.4 mm) were prepared according to ASTM D-790.

After making 4 hours at 175 ℃ cured specimens were measured at room temperature using a universal testing machine (UTM).

(Flame retardance): Based on the UL 94 V-0 standard was evaluated based on 1/8 inch thickness.

(Forming): The epoxy resin compositions of Tables 1 and 2 were molded by transfer molding at 175 ° C. for 70 seconds using an MPS (Multi Plunger System) molding machine to prepare an FBGA (62 mm × 240 mm × 1.1 mm) package. After curing for 4 hours at 175 ° C (PMC; post mold cure) and cooled to room temperature. Then, the number of voids observed on the package surface was visually measured.

(Bending characteristic): The height difference from the ground at the center and the end of the diagonal direction of the upper surface was measured about the FBGA package produced for the said moldability evaluation using the non-contact laser measuring machine, respectively.

(Reliability): After the FBGA package having been evaluated for bending characteristics was dried at 125 ° C. for 24 hours, 5 cycles (one cycle was left for 10 minutes at −65 ° C., 5 minutes at 25 ° C., and 10 minutes at 150 ° C.). Thermal shock test). Thereafter, the package is left at 30 ° C. and 60% relative humidity condition for 120 hours, and then package cracks are generated after preconditioning condition of repeating the IR reflow once for 30 seconds at 260 ° C. for 30 seconds. Was evaluated visually. If a crack occurred at this stage, no further evaluation was conducted.

a) Thermal Shock Test: After 1000 cycles of the thermal shock test on the FBGA package that passed the precondition conditions, using the non-destructive tester C-SAM (Scanning Acoustical Microscopy) to determine the occurrence of internal and external cracks and internal peeling Evaluated.

(Unit: weight%)

(week)

  1) YX-4000, Japan Epoxy Resin

  2) Prototype (structure of formula 5, epoxy equivalent 280, softening point 60 ℃), Kolon

  3) Prototype (structure of formula 1, hydroxyl equivalent 210, softening point 70 ℃), Kolon

  4) MEH-7800-4S, Meiwa kasei

  5) MEH-7500-3S, Meiwa kasei

  6) ESB-400T, Sumitomo Chemical

  7) TPP, Hokko Chemical

  8) KBM-403, Shin Etsu silicon

From the above results, it was confirmed that the epoxy resin composition for semiconductor resin encapsulation of the present invention has an excellent effect in improving warpage of the package and improving flame retardancy, moldability, and reliability.

Claims (10)

In the epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, and an inorganic filler, a biphenyl-containing modified phenol novolac type phenol resin represented by the following formula (1) is used as the curing agent. Epoxy resin composition. [Formula 1]

Wherein the average of m and n is 1 to 10, respectively, The order may be arranged randomly in the formula (1).) The epoxy resin composition for semiconductor element sealing according to claim 1, wherein the hydroxyl equivalent of the biphenyl-containing modified phenol novolak-type phenol resin is 100 to 400, and the softening point is 40 to 120 ° C. The epoxy resin composition for semiconductor element sealing according to claim 1, wherein the biphenyl-containing modified phenol novolak-type phenol resin is used in an amount of 5 to 100% by weight based on the total curing agent. The semiconductor device according to claim 1, wherein the curing agent is used in combination with the biphenyl-containing modified phenol novolac-type phenolic resin represented by formula (2) or a polyfunctional phenolic resin represented by the following formula (3). Epoxy resin composition for sealing. [Formula 2]

(In the above formula, the average value of n is 0 to 7.) [Formula 3]

(In the formula, the average value of n is 1 to 7.) 2. The epoxy resin for sealing a semiconductor device according to claim 1, wherein a biphenyl-type epoxy resin represented by the following formula (4) or a biphenyl-containing modified novolak-type epoxy resin represented by the following formula (5) is used as the epoxy resin. Composition. [Formula 4]

(In the above formula, the average value of n is 0 to 7.) [Formula 5]

(In the above formula, the average value of m and n are 1 to 10, respectively, and the order of the two repeating units may be randomly arranged in Formula 5.) The epoxy resin composition for sealing a semiconductor device according to claim 5, wherein an epoxy equivalent of the biphenyl-containing modified novolac epoxy resin is 100 to 400, and a softening point is 40 to 80 ° C. According to claim 1, wherein the inorganic filler is 3 to 20% by weight of spherical molten silica having an average particle diameter of 0.1 to 3㎛, 5 to 30% by weight of spherical molten silica having an average particle diameter of 3 to 10㎛, the average particle diameter of 10 to 25㎛ Epoxy resin composition for sealing a semiconductor device, characterized in that it comprises a molten silica mixture containing 50 to 92% by weight of the spherical fused silica to 40 to 100% by weight relative to the total inorganic filler. The epoxy resin composition for sealing a semiconductor device according to any one of claims 1 to 7 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. The semiconductor device according to claim 8, wherein the final powder product is sealed by low pressure transfer molding, injection molding, or casting molding. The semiconductor device of claim 9, 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.