KR100836571B1 - 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 improve an adhesiveness with various members such as a semiconductor device and a lead frame, and to ensure crack resistance upon substrate mounting. An epoxy resin composition for encapsulating a semiconductor device includes an epoxy resin, a hardener, a hardening accelerator, a coupling agent, and an inorganic filler. A benzotriazole-based compound represented by the following formula 1 is contained in an amount 0.01-2wt% of the total epoxy resin composition. In the formula 1, each of R1 and R2 is any one selected from a hydrogen atom, a mercapto group, an amino group, a hydroxyl group, and a C1-8 hydrocarbon chain.

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 semiconductor devices, and more particularly, to a copper lead frame having excellent crack resistance and silver plating, or a copper lead coated with silver and / or gold after nickel / palladium plating. It is related with the epoxy resin composition for semiconductor element sealing excellent in adhesiveness with a frame.

In recent years, the lead-discharge of leaded components in electric / electronic products that have been discarded has been found to be harmful to the human body. Particularly, legislation on lead regulation is actively underway, especially in Europe, and the Restriction of Hazardous Substances (RoHS) regulations will soon lead to the enforcement of inorganic chemicals such as lead, mercury, cadmium, and hexavalent chromium, as well as bromine-based organic flame retardants. to be.

Therefore, active development of lead-free products is required because all parts containing hazardous substances in electrical / electronic products must be replaced in an environmentally-friendly manner before the regulation law is enforced. In the electrical / electronic parts makers and sets makers, the subjects to be lead-free in electronic parts are as follows.

Currently, solders are mostly lead-free solders overseas, and Sn-Pb Plating is gradually becoming lead-free. In order to replace the existing Sn-Pb plating, lead-free methods currently being developed include pure Sn plating and nickel-palladium pre-plating. -plating).

Some large semiconductor makers are actively investigating how to tin-alloy alloy lead frames or copper lead frames, or the problem of overcoming whisker problems remains. It is expected to take considerable time for mass production. Nickel-palladium-silver (Ni-Pd-Ag) or nickel-palladium-silver / gold (Ni-Pd-Ag / Au) preplating (aka PPF: Pre-Plated Frame) is an alternative to overcome this problem. Particularly in Europe, the replacement of copper lead frames to PPF lead frames is actively underway, and the use of PPF lead frames is expected to increase significantly.

However, the PPF lead frame had a problem that reliability was significantly lowered, such as peeling after post-curing and reliability test, because the interface adhesion with the epoxy resin composition was very low compared to the lead alloy made of conventional alloy and copper.

In general, in order to improve the reliability reduction after welding, a method of maintaining high fluidity by using a low viscosity resin while improving crack resistance by increasing the amount of the inorganic filler to achieve low moisture absorption and low thermal expansion, Reliability after a welding process will depend more heavily on the adhesive force in the interface with the hardened | cured material of an epoxy resin composition, and base materials, such as a semiconductor element and lead frame which exist inside a semiconductor device. If the adhesion force at this X interface is weak, peeling occurs at the interface with the substrate after the welding treatment, and further cracking occurs in the semiconductor element due to this peeling.

Therefore, amine coupling agents and the like have been added to resin compositions for the purpose of improving the adhesive force at the interface (JP-A-2002-105172, J-A-2002-155130), but the welding treatment temperature by lead-free softening. With the rise of (215 ~ 240 ℃ → 260 ℃) and the appearance of PPF lead frame, it has reached the limit of sufficient attachment performance.

The present invention is to solve the problems of the prior art as described above, the epoxy resin composition for semiconductor element sealing to improve the adhesion to various members such as semiconductor elements, lead frames, etc., and to improve the crack resistance at the time of mounting the substrate 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, a coupling agent, and an inorganic filler, the benzobenzotriazole-based compound represented by the following formula (1) is 0.01 to 2 wt% based on the total epoxy resin composition Provided is an epoxy resin composition for sealing a semiconductor device and a semiconductor device using the same.

[Formula 1]

(R1 and R2 each independently represents a hydrogen atom, a mercapto group, an amino group, a hydroxyl group or a hydrocarbon chain having 1 to 8 carbon atoms.)

delete

The epoxy resin is characterized in that it comprises a biphenyl epoxy resin represented by the formula (2) or phenol aralkyl type epoxy resin represented by the following formula (3).

[Formula 2]

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

[Formula 3]

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

The curing agent is characterized in that it comprises a phenol aralkyl type phenol resin represented by the following formula (4) or a xylox type phenol resin represented by the following formula (5).

[Formula 4]

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

[Formula 5]

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

As the inorganic filler, a molten silica mixture including 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 size of 0.001 to 1 µm was applied to the entire filler. It is characterized in that it comprises so that the wt%.

The present invention also provides a semiconductor device, wherein the epoxy resin composition is mixed using a Henschel mixer or a solid 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 pre-plated with a material containing nickel and palladium.

Hereinafter, the present invention will be described in detail.

The present invention relates to an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a coupling agent, and an inorganic filler, wherein the epoxy resin composition further comprises a benzobenzotriazole compound represented by Formula 1 below. A composition VII and a semiconductor device using the same are provided.

[Formula 1]

(R1 and R2 each independently represents a hydrogen atom, a mercapto group, an amino group, a hydroxyl group or a hydrocarbon chain having 1 to 8 carbon atoms.)

The benzotriazole-based compound is a corrosion inhibitor of the metal. In the present invention, since the corrosion of the lead frame generated during the evaluation of the moisture absorption reliability of the semiconductor package may interfere with the interfacial bonding, thereby lowering the adhesion and adversely affecting the reliability, the present invention is intended to prevent corrosion of the leadframe and maintain the interfacial adhesion with the substrate. Apply the substance.

In general, corrosion is a phenomenon in which the performance of a metal product is degraded by reacting with a component present in the surrounding environment where the metal is in contact with the metal. In general, corrosion is dissolved in an acid / base corrosion solution to suppress corrosion and then surface treatment on the metal. Method is used. That is, the adsorbent of the corrosion inhibitor is a substance exhibiting activity between the corrosion solution and the metal surface (the adsorbent is electrometallic and non-organic, and the hydrocarbon group is small metal and organic). It is dispersed and easily adsorbed, and after being strongly adsorbed on the metal surface, the property is not easily desorbed from the metal. Therefore, in the present invention, the benzotriazole-based compound is smoothly dispersed in the epoxy resin composition instead of the corrosion solution, so as to prevent desorption from the metal after being attached to the metal surface. Through this, to reduce the adhesion between the substrate and the metal to provide a highly reliable semiconductor sealing material. In addition, the strength of the adsorption is largely influenced by the atoms involved in the adsorption, but the influence of other atoms depending on the atoms serving as the adsorption center cannot be ignored. Since the adsorption center atom donates electrons to the metal, the adsorption center of the material used for suppressing corrosion is centered on an element having a high electron density. Therefore, the adsorption group of the material used for the corrosion inhibitor is centered on the elements of Group V and VI of the periodic index with high electron density, and especially the benzotriazole-based compound of Formula 1 containing N has high electronegativity. It has a degree to inhibit the corrosion of metal (Cu, Alloy, Ag, etc.) to prevent the deterioration of adhesion at the interface between the metal and the epoxy resin composition.

The benzotriazole-based compound is used in an amount of 0.01 to 2% by weight based on the total epoxy resin composition. When the content is less than 0.01% by weight based on the total epoxy resin composition, the benzotriazole-based compound may not sufficiently have an effect of improving adhesion to metals such as PPF. On the other hand, when used in excess of 2% by weight may cause the problem of mixing raw materials and decrease the curing reaction. The benzotriazole-based compound may be directly added to the epoxy resin composition during the preparation of the epoxy resin composition, or dissolved in advance in a melt of an epoxy or a curing agent through a method such as melt master batch (MBM), and then used in the composition.

Examples of the epoxy resin of the present invention include cresol novolac epoxy resins, phenol novolac epoxy resins, biphenyl epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, linear aliphatic epoxy resins, and alicyclic epoxy resins. Resins, heterocyclic epoxy resins, epoxy resins including spiro rings and xylox epoxy resins, phenol aralkyl type epoxy resins, and the like, and two or more of them may be used. For example, the biphenyl type epoxy resin represented by General formula (2) and the phenol aralkyl type epoxy resin represented by General formula (3) are mentioned.

[Formula 2]

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

[Formula 3]

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

Preferred epoxy resins include biphenyl type epoxy resins represented by Formula 2, and it is preferable to use them at 40 wt% or more, particularly 70 wt% or more, based on the total epoxy resin. The said biphenyl type epoxy resin can exhibit sufficient effect even if it is single or a mixture, and can also be used as an addition compound which made partial reaction to the said biphenyl type epoxy resin. The total epoxy resin used in the present invention is preferably 3 to 15% by weight, more preferably 3 to 12% by weight based on the total epoxy resin composition.

The curing agent used in the present invention is a substance capable of making a cured product by reacting with an epoxy resin. Specific examples thereof include a phenol novolak resin, a cresol novolak resin, a xylox phenol resin, a phenol aralkyl phenol resin, bisphenol A and a resol. Various polyhydric phenol compounds such as various novolac resins, tris (hydroxyphenyl) methane, dihydroxybiphenyl, acid anhydrides such as maleic anhydride and phthalic anhydride, and metaphenylenediamine, diaminodiphenylmethane, diaminoiphenyl sulfone, etc. And aromatic amines. Phenol-based curing agents are widely used in terms of heat resistance, moisture resistance, and storage properties for semiconductor molding, and two or more kinds of curing agents may be used in parallel depending on the use. For example, the phenol aralkyl type phenol resin represented by General formula (4) and the xylox type phenol resin represented by General formula (5) are mentioned.

[Formula 4]

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

[Formula 5]

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

Preferred phenolic resins include phenol aralkyl type phenolic resins such as the formula (4), and it is preferable to use 20% by weight or more, particularly 30% by weight or more, based on the total phenolic resin. The total curing agent used in the present invention is preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight based on the total epoxy resin composition. The ratio of the epoxy resin and the curing agent is preferably used in the chemical equivalence ratio of the curing agent in the range of 0.5 to 2 kPa, in particular 0.8 to 1.6 kPa, based on the demands on mechanical properties and moisture resistance reliability.

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 amine, organometallic compound, organophosphorus compound, imidazole, boron compound and the like can be used. Tertiary amines include benzyldimethylamine, 2-2- (dimethylaminomethyl) phenol, salts of 2,4,6-tris (diaminomethyl) phenol and tri-2-ethylhexyl acid. Organometallic compounds include chromium acetylacetonate, zinc acetylacetonate, nickel acetylacetonate, and the like. Organophosphorus compounds include tris-4-methoxyphosphine, tetrabutylphosphonium bromide, butyltriphenylphosphonium bromide, triphenylphosphine, triphenylphosphinetriphenylborane, triphenylphosphine-1,4-benzoquinone Additives and the like. The imidazoles include 2-methylimidazole, 2-aminoimidazole, 2methyl-1-vinylimidazole, 2-ethyl-4-methylimidazole, 2-heptadecyl imidazole, and the like. Examples of the boron compound include trifluoroborane-n-hexylamine, trifluoroborane monoethylamine, tetrafluoroborane triethylamine, tetrafluoroboraneamine 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 .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 those used alone or in combination with basic curing accelerators such as amines and imidazoles. The curing accelerator may also use an adduct made by prereacting with an epoxy resin or a hardening agent. The amount of the curing accelerator used in the present invention is preferably from 0.001 to 1% by weight, more preferably from 0.01 to 0.5% by weight based on the total amount of epoxy resin composition.

The inorganic filler used in the present invention is a material used for improving the mechanical properties and low stress of the epoxy resin composition. 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 molten silica refers to amorphous silica having a specific gravity of 2.3 Pa or less, and includes amorphous 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. The mixture may preferably comprise from 40 to 100% by weight relative to the total filler. In addition, it can be used by adjusting the maximum particle diameter to any one of 45 micrometers, 55 micrometers, and 75 micrometers according to a use. In fused spherical silica, conductive carbon may be contained as a foreign material on the silica surface, but it is also important to select a material with little foreign matter mixed. The proportion of the filler in the present invention depends on the required physical properties such as formability, low stress, high temperature strength, etc., but is preferably used in the range of 70 to 95% by weight relative to the total epoxy resin composition, the ratio of 82 to 92% by weight More preferably.

Epoxy resin composition of the present invention is a release agent such as higher fatty acids, higher fatty acid metal salts, ester waxes, colorants such as carbon black, organic dyes, inorganic dyes, epoxysilanes, aminosilanes, mercaptosilanes within the scope of not impairing the object of the present invention. Coupling agents such as alkylsilanes, alkoxysilanes, stress relieving agents such as modified silicone oils, silicone powders and silicone resins, brominated epoxy resins, oils such as antimony oxide, phosphazene, zinc borate, aluminum hydroxide and magnesium hydroxide, and inorganic flame retardants It may 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 Rödige 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, a 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 lead frame or organic laminate frame can be manufactured.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

[Examples 1 to 3 and Comparative Examples 1 and 2]

In order to prepare the epoxy resin composition for sealing a semiconductor device of the present invention, each component was weighed as shown in Table 1, and then uniformly mixed using a Henschel mixer to prepare a powder primary composition. After melt kneading in the range of 100 ~ 120 ℃ ℃, through the cooling and grinding process to prepare an epoxy resin composition. The epoxy resin composition thus obtained was evaluated for physical properties and reliability by the following method, and after molding for 70 seconds at 175 ℃ using a multi-plunger system (MPS) molding machine for a reliability test, after 4 hours at 175 ℃ By curing, a medium quad flat package (MQFP) type semiconductor device composed of a lead frame in which nickel-palladium-gold was preplated on a Cu metal device was fabricated. Physical properties and the reliability test results of the epoxy resin composition according to the present invention are shown in Table 2 below. The reliability test was expressed in terms of peeling and package cracking degree in the thermal shock test.

* Adhesion: A copper metal element to be measured was prepared in a standard suitable for an adhesion measurement mold, and a test piece prepared by pre-plating nickel-palladium-gold and nickel-palladium-gold / silver on the prepared copper metal specimen. The epoxy resin composition shown in Table 1 was prepared on a metal test specimen prepared under the conditions of a mold temperature of 170 to 180 ° C., a feed pressure of 1000 psi, a feed rate of 0.5 to 1.0 cm / sec, and a curing time of 120 seconds to obtain a cured specimen. Immediately after post-curing for 4 hours in an oven at 180 ° C. and left for 60 hours at 60 ° C. and 60% relative humidity conditions, followed by three passes of IR reflow once for 30 seconds at 260 ° C. The adhesion force under the condition was respectively measured. At this time, the area of the epoxy resin composition in contact with the metal specimen is 33 ~ 40mm ² and the adhesion measurement was measured using a universal testing machine (UTM) for 10 or more specimens per each measurement process.

* Peeling resistance evaluation (reliability test): LQFP type semiconductor device composed of lead-frame plated nickel-palladium-cracked pre-plated on copper metal element using the epoxy resin composition of Table 1 for 4 hours at 175 ℃ Post-cure for The LQFP semiconductor device was dried at 125 ° C. for 24 hours, then left at 60 ° C. and 60% relative humidity for 120 hours, and then subjected to three times of repeated IR reflows at 260 ° C. for 30 seconds. The appearance of cracks in package appearance under the condition was evaluated by an optical microscope. In addition, using a non-destructive tester C-SAM (Scanning Acoustical Microscopy) was used to evaluate the occurrence of cracks between the epoxy resin composition and the lead frame.

Ingredient (Unit: wt%) Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Epoxy resin Phenolic Aralkyl Epoxy Resin ^{Note 1)} 4.17 Biphenyl Epoxy Resin ^{Note 2)} 1.92 Hardener Xylox Phenolic Resin ^Note3) 3.89 Phenolic Aralkyl Type Phenolic Resin ^{Note 4)} 0.55 Curing accelerator Triphenylphosphine series ^{Note 5)} 0.20 Inorganic filler Silica ^{Note 6)} 88.00 Coupling agent Murray captopril trimethoxysilane ^{* 7)} 0.05 0.05 0.05 0.05 0.35 Methyltrimethoxysilane ^{Note 8)} 0.10 0.14 0.24 0.24 0.30 Amine Silanes ^{Note 9)} 0.09 0.15 0.15 0.45 0.09 additive Benzotriazole Compounds ^{Note 10)} 0.50 0.40 0.30 - - coloring agent Carbon black 0.25 Wax Carnauba Wax 0.28

Note 1) NC-3000, Nippon Kayaku

Note 2) YX-4000, Japan Epoxy Resin

Note 3) KPH-F3060, Kolon Oil Painting

Note 4) MEH-7851, Meiwa

Note 5) TPP-k, Hokko Chemical

Note 6: 9: 1 mixture of spherical molten silica with an average particle diameter of 18 µm and spherical molten silica with an average particle diameter of 0.5 µm

Note 7) KBM-803, Shin Etsu Silicon

Note 8) SZ-6070, Dow corning chemical

Note 9) KBM-573, Shin Etsu Silicon

Note 10) 2- (2'-Hydroxy-5'-octylphenyl) benzotriazole

[Comparative Example]

As shown in Table 1, the epoxy resin composition was prepared in the same manner as in Example by weighing each component in a given composition, and the results of evaluation of physical properties and reliability are shown in Table 2 below.

Evaluation item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Spiral Flow (inch) 37 41 39 35 37 Tg (℃) 125 124 122 122 123 Adhesion force (kgf) Cu After PMC 120 120 120 120 120 After 60 ℃ / 60% + 120hrs 115 115 115 115 115 Alloy 42 After PMC 80 80 80 80 80 After 60 ℃ / 60% + 120hrs 78 78 78 78 78 Ag After PMC 67 66 64 28 45 After 60 ℃ / 60% + 120hrs 60 60 58 16 29 PPF After PMC 84 81 75 40 54 After 60 ℃ / 60% + 120hrs 80 76 73 28 32 Flame retardant UL 94 V-0 V-0 V-0 V-0 V-0 V-0 responsibility Crack Resistance Evaluation 0 0 0 120 100 Total number of semiconductor devices tested 200 200 200 200 200

As shown in Table 2, it was confirmed that the epoxy resin composition according to the present invention sufficiently secured the adhesion force immediately after the post-curing and after three passes of the IR reflow, compared to the conventional comparative example, and did not apply a separate flame retardant. It can be seen that the excellent flame retardancy is secured without.

In particular, in terms of reliability, an epoxy resin composition excellent in peeling resistance and crack resistance with a lead frame pre-plated with nickel-palladium after reflow was obtained.

As described above, according to the epoxy resin composition for sealing a semiconductor device of the present invention, due to the improved adhesion in the pre-plated frame, the reliability is high, and at the same time, excellent flame retardancy is required without using a flame retardant such as halogen-based antimony trioxide or the like. The branch can manufacture a resin-sealed semiconductor element.

Claims (8)

An epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a coupling agent, and an inorganic filler, wherein the benzobenzotriazole compound represented by the following Chemical Formula 1 is contained in an amount of 0.01 to 2 wt% based on the total epoxy resin composition. Epoxy resin composition for sealing semiconductor elements. [Formula 1]

(R1 and R2 each independently represents a hydrogen atom, a mercapto group, an amino group, a hydroxyl group or a hydrocarbon chain having 1 to 8 carbon atoms.) delete The epoxy resin composition for sealing a semiconductor device according to claim 1, wherein the epoxy resin comprises a biphenyl epoxy resin represented by the following Chemical Formula 2 or a phenol aralkyl type epoxy resin represented by the following Chemical Formula 3. [Formula 2]

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

(In the above formula, the average value of n is 1 to 7.) The epoxy resin composition for sealing a semiconductor device according to claim 1, wherein the curing agent comprises a phenol aralkyl type phenol resin represented by the following formula (4) or a xylock type phenol resin represented by the following formula (5). [Formula 4]

(In the above formula, the average value of n is 1 to 7.) [Formula 5]

(In the above formula, the average value of n is 1 to 7.) The molten silica mixture of claim 1, wherein the inorganic filler comprises 50 to 99 wt% of spherical molten silica having an average particle diameter of 5 to 30 µm and 1 to 50 wt% of spherical molten silica having an average particle diameter of 0.001 to 1 µm. An epoxy resin composition for sealing a semiconductor device, characterized in that the filler so as to be 40 to 100% by weight relative to the filler. The epoxy resin composition for sealing a semiconductor element according to any one of claims 1 and 3 to 5 is mixed using a Henschel mixer or a solid mixer, and melt-kneaded with a roll mill or a kneader, followed by cooling, Semi-conductor element sealed with the final powder product obtained through grinding process. 7. The semiconductor device according to claim 6, wherein the final powder product is sealed by a low pressure transfer molding method, an injection molding method, or a casting molding method. 8. The semiconductor device of claim 7, wherein the semiconductor device comprises a lead frame pre-plated with a material comprising nickel and palladium.