KR100806420B1 - Epoxy resin composition for sealing semiconductor element - Google Patents

Abstract

The present invention relates to an epoxy resin composition for encapsulating semiconductor devices, and more particularly, to improve adhesion between a lead frame plated with copper or silver and an epoxy resin composition, and to reduce interfacial peeling after a solder reflow process. It is related with the epoxy resin composition which can improve significantly. The epoxy resin composition which concerns on this invention mixes and uses an imidazole silane coupling agent, a mercapto silane coupling agent, and an epoxy silane coupling agent.

Semiconductor element, epoxy, imidazole silane, mercapto silane, coupling agent

Description

Epoxy resin composition for sealing semiconductor element

1 and 2 is a schematic view showing a specimen consisting of a lead frame and an epoxy resin composition for measuring the adhesion of the epoxy resin composition for sealing semiconductor device according to the present invention and the tensile force applied to the specimen.

The present invention relates to an epoxy resin composition for encapsulating a semiconductor device, and more particularly, by using a coupling agent of a specific structure, adhesion between the lead frame and the epoxy resin composition is improved, and a solder reflow process is performed. The present invention relates to an epoxy resin composition for semiconductor device encapsulation, in which post-interface peeling is reduced to improve reliability of a package.

In general, manufacturing steps of a semiconductor device may be divided into a pattern design step, a substrate manufacturing step, a component insertion step, a soldering step, a cutting step, and a cleaning step. Since the solder reflow process of the soldering step is rapidly processed with a high temperature lead solution that is 20 ° C. or higher than other temperatures, reliability of the sealing material of the semiconductor device is particularly required, and this quality is the quality of the final semiconductor device. It becomes a big factor influencing. In addition, as the movement to remove environmentally harmful substances from semiconductor materials continues, there is an ongoing process of replacing lead used in soldering with another metal. According to this trend, high reliability encapsulants that do not cause cracks or interfacial delamination even in solder reflow processes of 260 ° C. or higher have been demanded and developed instead of the conventional semiconductor encapsulants.

However, using only the epoxy silane coupling agent represented by the following general formula (3) used in the conventional conventional epoxy resin composition for semiconductor encapsulant, it is possible to crack the encapsulant in the solder reflow process of 260 ° C or higher, and to remove the interface between the lead frame and the encapsulant. The phenomenon could not be prevented.

Accordingly, an object of the present invention is to provide an epoxy resin composition for semiconductor element encapsulation with improved reliability by mixing and using a coupling agent having a specific structure in order to ensure high reliability in the high temperature solder reflow process as described above.

Epoxy resin composition according to the present invention for achieving the above object, in the epoxy resin composition consisting of an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, a coupling agent, a flame retardant, a coloring agent and an additive, represented by the formula (1) It is characterized by using a silane coupling agent, a mercapto silane coupling agent represented by the following formula (2) and an epoxy silane coupling agent represented by the following formula (3).

Formula 3

Wherein R ₁ and R ₂ are one selected from the group consisting of alkyl groups having 18 or less carbon atoms and aromatic hydrocarbons, R ₃ is one selected from the group consisting of hydrocarbons having 10 or less carbon atoms, with or without a hydroxy group, and R ₄ is One selected from the group consisting of alkyl groups having up to 5 carbon atoms. R ₅ is one selected from the group consisting of hydrocarbons having 6 or less carbon atoms, R ₆ is one selected from the group consisting of alkyl groups having 5 or less carbon atoms, n is an integer of 1 to 3, m is 2 or less and n + m An integer that satisfies = 3.

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

As described above, the epoxy resin composition according to the present invention consists of an epoxy resin, a curing agent, a curing accelerator, an inorganic filler, a coupling agent, a flame retardant, a coloring agent, and an additive, and in particular, the imidazole silane coupling agent represented by Formula 1, The mercapto silane coupling agent represented by the formula (2) and the epoxy silane coupling agent represented by the formula (3) are mixed and used.

The epoxy resin composition used in the present invention is 3 to 15% by weight of epoxy resin, 3 to 15% by weight of curing agent, 0.1 to 1.0% by weight of curing accelerator, 70 to 92% by weight of inorganic filler, 0.1 to 1.0% by weight of Coupling agent (total of the coupling agent represented by Formula 1, Formula 2 and Formula 3), colorant within 1.0% by weight, flame retardant within 2% by weight, and other additives of 1 to 5% by weight.

The epoxy resin used in the present invention is not particularly limited, and one or two or more resins selected from the group consisting of ortho cresol novolac type, biphenyl type, polyfunctional type, naphthalene type and dicyclopentadiene type epoxy resins are mixed. The total amount of epoxy resins used is preferably 3 to 15% by weight.

The curing agent used in the present invention is not particularly limited as a phenol resin, and at least one resin selected from the group consisting of novolak type, xylox type, multiaromatic type, polyfunctional type, naphthalene type and dicyclopentadiene type phenol resins. 3 to 15% by weight of the total amount of the curing agent is preferable.

The inorganic filler used in the present invention is not particularly limited, and high-purity natural silica, synthetic silica, fused silica, alumina, and the like may be used. In order to achieve the desired high reliability in the present invention, it is preferable to apply the inorganic filler at 70 to 92% by weight.

The flame retardant used in the present invention includes both the case of using the conventional brominated epoxy and antimony trioxide, the case of using the phosphorus or phosphorus compound, and the case of the flame retardant by the use of the flame retardant resin, and in all cases the same result Indicates.

As the coupling agent used in the present invention, 0.02 to 0.3 wt% of the imidazole silane coupling agent represented by the above formula (1) while using an epoxy silane represented by the above formula (3) which is a common coupling agent at 0.07 to 0.9 wt%, and The mercapto silane coupling agent represented by Formula 2 may be used in an amount of 0.01 to 0.2% by weight, and in the present invention, for the sake of high reliability of the semiconductor, the total of the three coupling agents is preferably 0.1 to 1.0% by weight. .

In addition, in the case of the imidazole silane coupling agent represented by the formula (1) as a highly viscous liquid compound, pretreatment is carried out for dispersion in the epoxy resin composition, the epoxy resin or a phenol resin which is a curing agent is melted at 110 ~ 150 ℃ After injecting, the imidazole silane coupling agent is slowly injected, mixed, cooled and pulverized, and the pretreatment is preferred for high reliability of the semiconductor of the present invention.

Meanwhile, in the case of the mercapto silane coupling agent represented by Chemical Formula 2, it is a low viscosity liquid compound, which is preferably used for pretreatment with an inorganic filler in order to secure high dispersibility. During the slow stirring of the filler, the mercapto silane coupling agent is sprayed and pretreated.

Moreover, in this invention, it is also possible to add the mold release agent, a coloring agent, a modifier, a hardening accelerator, etc. which are generally applied.

The epoxy resin composition for encapsulating the semiconductor device of the present invention is mixed with each raw material and then melt mixed at a temperature of 80 ℃ to 130 ℃ using a melt mixer (Kneader) to cool to room temperature and pulverized into a powder state after the blending process The fermentation may be manufactured by a general manufacturing method.

Hereinafter, the present invention will be described in more detail, but the scope of the present invention is not limited thereto.

Examples 1 and 2

As the epoxy resin, a biphenyl type epoxy resin is used, and as a curing agent, a mixture of xylox and multiaromatic phenol resins is used in an equivalent ratio of 50 to 50, and as a coupling agent, an epoxy silane coupling agent represented by Formula 3 above is used. , And a coupling agent represented by the following formulas 4 and 5 were used by mixing, the inorganic filler was used as silica. The content of each component is shown in Table 1 below, and after mixing the raw materials together, the mixture was subjected to melt mixing, cooling, pulverization, blending process and compressed to a certain size. At this time, the imidazole silane coupling agent represented by the following formula (4) is taken 1.44% by weight of phenol resin (40% of 3.6% by weight of phenol resin) as a curing agent and melted at 110 ℃ and slowly inject the imidazole silane coupling agent After mixing, the mixture was cooled and pulverized, and the mercapto silane coupling agent represented by the following formula (5) was pretreated by spraying the mercapto silane coupling agent with a spray while stirring the entire silica, which is an inorganic filler, at low speed.

Using the epoxy resin composition thus obtained, in the heat transfer molding machine (pressure = 70kg / ㎠, temperature = 175 ℃, curing time = 120 seconds) to prepare a specimen for measuring the adhesion as shown in Figure 1 constant temperature and humidity (85 ℃ / 85% RH Adhesion with the copper lead frame was measured before and after the moisture absorption at 48 hours, and molded in an LQFP package (Body size: 24mm × 24mm × 1.4mm, 176 leads) attached with a Si ₃ N ₄ chip, and then at 175 ° C. After curing for 4 hours, absorbing at constant temperature and humidity (85 ° C / 85% RH) for 48 hours, applying IR-reflow (maximum temperature = 260 ° C) three times in succession, and then using ultrasonic flaw detector (SAT) Interfacial delamination between the lead frame and the encapsulant was measured and shown in Table 1 below.

Comparative Example 1

Each component and content were mixed as in Table 1 to prepare an epoxy resin composition in the same manner as in Example 1, and the analysis results are shown in Table 1 below.

division unit Example 1 Example 2 Comparative Example 1 Epoxy resin weight% 6.7 6.7 6.7 Phenolic Resin weight% 3.6 3.6 3.6 Curing accelerator weight% 0.2 0.2 0.2 Silica weight% 87.2 87.2 87.2 additive weight% 0.6 0.6 0.6 Brominated Epoxy weight% 0.4 0.4 0.4 Antimony trioxide weight% 0.8 0.8 0.8 Formula 3 weight% 0.4 0.4 0.5 Formula 4 weight% 0.05 0.07 Formula 5 weight% 0.05 0.03 Property evaluation result Adhesion with Copper (Before Hygroscopic) MPa 4.5 5.3 3.8 Adhesion with copper (after moisture absorption) MPa 4.3 4.9 3.1 Package Peel Off (Upper Pad) % 0 0 100 Package Peeling (Bottom Pad) % 10 0 40

Examples 3 to 5

Each component and content were mixed as in Table 2 to prepare an epoxy resin composition in the same manner as in Example 1, and the analysis results are shown in Table 2 below.

Comparative Examples 2-4

Each component and content were mixed as in Table 2 to prepare an epoxy resin composition in the same manner as in Example 1, and the analysis results are shown in Table 2 below.                     

division unit Example 3 Example 4 Example 5 Comparative Example 2 Comparative Example 3 Comparative Example 4 Epoxy resin weight% 6.7 6.7 6.7 6.7 6.7 6.7 Hardener weight% 3.6 3.6 3.6 3.6 3.6 3.6 Curing accelerator weight% 0.2 0.2 0.2 0.2 0.2 0.2 Silica weight% 87.2 87.2 87.2 87.2 87.2 87.2 additive weight% 0.6 0.6 0.6 0.6 0.6 0.6 Brominated Epoxy weight% 0.4 0.4 0.4 0.4 0.4 0.4 Antimony trioxide weight% 0.8 0.8 0.8 0.8 0.8 0.8 Formula 3 weight% 0.19 0.28 0.47 0.14 0.20 Formula 4 weight% 0.30 0.02 0.02 0.30 0.35 0.05 Formula 5 weight% 0.01 0.2 0.01 0.20 0.01 0.25 Property evaluation result Adhesion with Copper (Before Hygroscopic) MPa 5.3 4.4 4.6 4.0 3.9 3.5 Adhesion with copper (after moisture absorption) MPa 5.0 3.8 4.0 3.3 3.2 2.9 Package Peel Off (Upper Pad) % 20 15 20 80 85 80 Package Peeling (Bottom Pad) % 0 5 10 40 50 70

The measuring method for each property is as follows.

* Adhesive force measurement

In order to produce a specimen of the form as shown in Figure 1 using a lead frame and a mold in a heat transfer molding machine (pressure = 70kg / ㎠, temperature = 175 ℃, curing time = 120 seconds) after molding for 4 hours in an oven at 175 ℃ After the post-cure, the load was applied to the point where the lead frame fell from the epoxy resin composition while applying tensile force in the direction as shown in FIG. 2 before and after 48 hours at 85 ° C./85%RH. It measures and converts into adhesive force value (MPa). At this time, (1) is an epoxy resin composition, and (2) shows a copper frame.

* Package Peeling Measurement

Molded in a heat transfer molding machine (pressure = 70kg / ㎠, temperature = 175 ℃, curing time = 120 seconds) using a LQFP package (Body size: 24mm × 24mm, 176 lead) mold with SiN chip, and then 175 ℃. After 4 hours of curing at 48 ° C / 85% RH for 48 hours, the ultrasonic flaw detector (SAT) was applied after three consecutive applications of IR-reflow (maximum temperature = 260 ° C). The peel rate (%) of the package pad portion, that is, the interface between the encapsulant and the pad top and the SiN chip surface, and the interfacial peel rate (%) between the encapsulant and the pad lower lead frame, were measured by 10 cavities, respectively. Indicated.

As can be seen from the examples and comparative examples, when encapsulating a semiconductor device with a resin composition obtained by mixing the imidazole silane coupling agent, the mercapto silane coupling agent and the epoxy silane coupling agent according to the present invention, the lead frame The adhesion between the resin and the epoxy resin composition is improved, the interface peeling after the solder reflow process is reduced, and the reliability of the package is greatly improved.

Claims (5)

3-15 wt% epoxy resin, 3-15 wt% curing agent, 0.1-1.0 wt% curing accelerator, 70-92 wt% inorganic filler, 0.1-1.0 wt% coupling agent, colorant within 1.0 wt% In the epoxy resin composition consisting of, within 2% by weight of a flame retardant, and 1 to 5% by weight of other additives, The coupling agent is 0.02 to 0.3% by weight of the imidazole silane coupling agent represented by the following formula (1), 0.01 to 0.2% by weight of the mercapto silane coupling agent represented by the formula (2) and 0.07 to 0.9% by weight of the formula Epoxy resin composition for sealing semiconductor device, characterized in that for use by mixing the epoxy silane coupling agent shown: Formula 1

Formula 2

Formula 3

Wherein R ₁ and R ₂ are one selected from the group consisting of alkyl groups having 18 or less carbon atoms and aromatic hydrocarbons, R ₃ is one selected from the group consisting of hydrocarbons having 10 or less carbon atoms, with or without a hydroxy group, and R ₄ is One selected from the group consisting of alkyl groups having up to 5 carbon atoms. R ₅ is one selected from the group consisting of hydrocarbons having 6 or less carbon atoms, R ₆ is one selected from the group consisting of alkyl groups having 5 or less carbon atoms, n is an integer of 1 to 3, m is 2 or less and n + m An integer that satisfies = 3. delete delete The method of claim 1, wherein the imidazole silane coupling agent is pretreated by using a method of melting an epoxy resin or a phenol resin, which is a curing agent, at 110 to 150 ° C., injecting the imidazole silane coupling agent slowly, mixing the mixture, and then cooling and pulverizing it. Epoxy resin composition for semiconductor encapsulation characterized in that it is. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the mercapto silane coupling agent is used by spraying a mercapto silane coupling agent with a spray during pre-treatment of the inorganic filler.

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