Epoxy resin composition capable of low-temperature rapid curing and injection molding, and preparation method therefor

Abstract

The present invention relates to the technical field of injection molding in semiconductor packaging, in particular to an epoxy resin composition capable of low-temperature rapid curing and injection molding, and a preparation method therefor. Said epoxy resin composition at least comprises an o-cresol formaldehyde epoxy resin, a dicyclopentadiene phenolic epoxy resin, a phenol-aralkyl curing agent, an imidazole curing agent, a coupling agent, a release agent, a coloring agent and silicon dioxide. By means of optimization of the selection in compounding epoxy resins and curing agents, the combined use of the o-cresol formaldehyde epoxy resin and dicyclopentadiene phenolic epoxy resin as well as the phenol-aralkyl curing agent and the imidazole curing agent, and a low-temperature mixing process enable the provided epoxy resin composition to have a low packaging injection molding temperature and short packaging injection molding time, thereby effectively satisfying new demands in the semiconductor packaging industry.

Description

Low-temperature rapid-curing injection-molding epoxy resin composition and preparation method thereof Technical Field

[0001] The present invention relates to the technical field of semiconductor packaging injection molding, in particular to a low-temperature fast-curing injection molding epoxy resin composition and a preparation method thereof. Background Art

[0002] Semiconductor package injection molding is primarily completed in the back-end process of semiconductor manufacturing. It is a process in which semiconductor components and other components are arranged, fixed, and connected on a frame or substrate, and the wiring terminals are brought out. They are then encapsulated and fixed with epoxy molding compound to form the overall main structure. The most basic function of packaging is to protect the circuit chip from the influence of the surrounding environment (including physical and chemical influences). The injection molding temperature is usually 175°C, which is sensitive to some high-temperature resistant chips or electronic components. The industry hopes to lower the package injection molding temperature as much as possible to avoid affecting high-temperature resistant chips or electronic components. At the same time, in order to pursue production and work efficiency, semiconductor packaging factories hope to shorten the time of a single injection molding cycle as much as possible. Since the traditional injection molding time is generally 120 seconds, it greatly wastes time and energy. For example, the thermal curing temperature of the wafer-level encapsulation resin composition disclosed in the Chinese patent application (publication number CN110183818A) is 80-120°C, and the thermal curing time is 15 minutes to 45 minutes, which cannot meet the above-mentioned application requirements. The epoxy resin composition and semiconductor device disclosed in the Chinese patent application (publication number CN107793553A) have an epoxy resin composition injection molding temperature of 175°C and a time of 120s. Therefore, both cannot have a lower encapsulation injection molding temperature and a shorter encapsulation injection molding time at the same time, and cannot meet the new demands emerging in the semiconductor packaging industry. Summary of the Invention

[0003] In order to solve the above problems, the present invention provides an epoxy resin composition for low-temperature rapid curing injection molding. By optimizing the compound selection of epoxy resin and curing agent and adopting a low-temperature mixing process, the provided epoxy resin composition has a lower packaging injection molding temperature and a shorter packaging injection molding time, effectively meeting the new demands emerging in the semiconductor packaging industry.

[0004] On the one hand, the present invention provides a low-temperature fast-curing injection molding epoxy resin composition, which at least includes o-cresol epoxy resin, dicyclopentadiene phenol type epoxy resin, phenol-aralkyl type curing agent, imidazole curing agent, coupling agent, release agent, colorant, and silica.

[0005] As a preferred technical solution, the epoxy resin composition includes, by weight, at least 5-10 parts of o-cresol epoxy resin, 1-3 parts of dicyclopentadiene phenol type epoxy resin, 2-8 parts of phenol-aralkyl type curing agent, 2-8 parts of imidazole curing agent, 0.1-0.5 parts of coupling agent, 0.3-1 parts of release agent, 0.1-0.5 parts of colorant, and 80-87 parts of silica.

[0006] As a preferred technical solution, the mass ratio of the phenol-aralkyl type curing agent to the imidazole curing agent is (4-5): (3-4).

[0007] As a preferred technical solution, the epoxy equivalent of the o-cresol-formaldehyde epoxy resin is 180-220 g / eq, preferably 194-204 g / eq.

[0008] As a preferred technical solution, the epoxy equivalent of the dicyclopentadiene phenol type epoxy resin is 250-300 g / eq, preferably 260-280 g / eq.

[0009] As a preferred technical solution, the hydroxyl equivalent of the phenol-aralkyl type curing agent is 150-250 g / eq, preferably 168-174 g / eq.

[0010] As a preferred technical solution, the melting point of the imidazole curing agent is less than 100°C, preferably less than 90°C, and more preferably less than 50°C.

[0011] As a preferred technical solution, the curing time of the epoxy resin composition at 175° C. is ≤20s.

[0012] As a preferred technical solution, the curing time of the epoxy resin composition at 150° C. is ≤30s.

[0013] As a preferred technical solution, the curing time of the epoxy resin composition at 100° C. is ≤75s.

[0014] As a preferred technical solution, the spiral flow length (175° C.) of the epoxy resin composition is ≥25 inches.

[0015] As a preferred technical solution, the coupling agent is an aminosilane coupling agent, preferably X-12-972F, Shin-Etsu.

[0016] As a preferred technical solution, the release agent is one of natural wax, synthetic wax, fatty acid and metal salt thereof.

[0017] As a preferred technical solution, the silicon dioxide is spherical silicon dioxide, and the particle size of the silicon dioxide is less than 100 μm; preferably, the maximum particle size of the silicon dioxide does not exceed 80 μm.

[0018] The present invention optimizes the epoxy resin composition formula based on the new demand for injection time and injection temperature of epoxy molding compounds in the semiconductor packaging industry, and adopts o-cresol epoxy resin, dicyclopentadiene phenol type epoxy resin to cooperate with phenol-aralkyl type curing agent and imidazole curing agent to achieve low temperature injection molding and rapid curing. In particular, the epoxy equivalent of the epoxy resin, the hydroxyl equivalent of the phenol-aralkyl type curing agent and the mass ratio of the phenol-aralkyl type curing agent and the imidazole curing agent are controlled to be (4-5): (3-4), so that the epoxy resin composition provided has a lower curing temperature, a shorter curing time and a higher bending strength. Further, by introducing 80-87 parts by weight of silicon dioxide with a maximum particle size of no more than 80 μm and controlling the mixing temperature of the epoxy resin composition to be 80-100 ° C, it is ensured that the fluidity of the epoxy resin composition meets good filling properties.

[0019] On the other hand, the present invention provides a method for preparing a low-temperature fast-curing injection-molding epoxy resin composition. The method comprises mixing o-cresol epoxy resin, dicyclopentadiene phenol-type epoxy resin, phenol-aralkyl type curing agent, imidazole curing agent, coupling agent, release agent, colorant and silicon dioxide in parts by weight, and then passing the mixture through a low-temperature zone, a high-temperature mixing zone and a medium-temperature zone in sequence to obtain the epoxy resin composition.

[0020] Preferably, the temperature of the low temperature zone is 20-30°C, preferably 20-25°C.

[0021] Preferably, the temperature of the high temperature mixing zone is 80-100°C, preferably 80-85°C.

[0022] Preferably, the temperature of the low temperature zone is 50-65°C, preferably 60-65°C. Beneficial effects

[0023] 1. The present invention provides an epoxy resin composition for low-temperature rapid curing and injection molding. By optimizing the compounding selection of epoxy resin and curing agent and adopting a low-temperature mixing process, the provided epoxy resin composition has a lower packaging injection molding temperature and a shorter packaging injection molding time, effectively meeting the new demands of the semiconductor packaging industry.

[0024] 2. The present invention realizes low-temperature injection molding and rapid curing by using o-cresol epoxy resin, dicyclopentadiene phenol type epoxy resin, phenol-aralkyl type curing agent and imidazole type curing agent.

[0025] 3. The present invention controls the epoxy equivalent of the epoxy resin, the hydroxyl equivalent of the phenol-aralkyl type curing agent, and the mass ratio of the phenol-aralkyl type curing agent to the imidazole curing agent to (4-5): (3-4), so that the provided epoxy resin composition has a lower curing temperature, a shorter curing time and a higher flexural strength.

[0026] 4. The present invention introduces 80-87 parts by weight of silicon dioxide with a maximum particle size not exceeding 80 μm and controls the mixing temperature of the epoxy resin composition to 80-100° C. to ensure that the fluidity of the epoxy resin composition meets good filling properties. DETAILED DESCRIPTION

[0027] Examples 1-6

[0028] Examples 1-6 of the present invention provide a low-temperature, fast-curing injection-molding epoxy resin composition. The raw materials for its preparation are shown in Table 1, in parts by weight.

[0029] Table 1

[0030] On the other hand, Examples 1-6 of the present invention provide a method for preparing a low-temperature, fast-curing injection-molded epoxy resin composition, comprising mixing an o-cresol epoxy resin, a dicyclopentadiene phenol-type epoxy resin, a phenol-aralkyl type curing agent, an imidazole curing agent, a coupling agent, a release agent, a colorant, and silica, in parts by weight, and then sequentially passing through a low-temperature zone, a high-temperature mixing zone, and a medium-temperature zone to obtain the composition. The temperatures of the low-temperature zone, high-temperature mixing zone, and medium-temperature zone of each embodiment are shown in Table 1.

[0031] Performance Testing

[0032] 1. With reference to GB / T 33316-2016, the curing time of the epoxy resin materials provided in Examples 1-6 was tested. The test results are shown in Table 2.

[0033] 2. The spiral flow length of the epoxy resin provided in Examples 1-6 at 175° C. was tested. The test results are shown in Table 2.

[0034] 3. Referring to GB / T 22567-2008, the glass transition temperatures of the epoxy resins provided in Examples 1-6 were tested. The test results are shown in Table 2.

[0035] 4. Referring to ASTM 790D-17, the flexural modulus and flexural strength of the epoxy resin materials provided in Examples 1-6 were tested. The test results are shown in Table 2.

[0036] 5. With reference to GB / T40564-2021, the thermal expansion coefficients of the epoxy resin materials provided in Examples 1-6 were tested. The test results are shown in Table 2.

[0037] 6. Referring to GB / T40564-2021, the molding shrinkage of the epoxy resin materials provided in Examples 1-6 was tested. The test results are shown in Table 2.

[0038] 7. With reference to GB / T3139-2005, the thermal conductivity of the epoxy resin materials provided in Examples 1-6 was tested. The test results are shown in Table 2.

[0039] Table 2 Note: The mixing of Example 2 failed, and subsequent testing was not performed.

Claims

1. An epoxy resin composition for low-temperature rapid-curing injection molding, characterized in that, It includes at least o-cresol novolac epoxy resin, dicyclopentadiene phenol type epoxy resin, phenol-aralkyl type curing agent, imidazole type curing agent, coupling agent, release agent, colorant, and silica.

2. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 1, wherein The epoxy resin composition includes, by weight parts, at least 5-10 parts of o-cresol novolac epoxy resin, 1-3 parts of dicyclopentadiene phenol type epoxy resin, 2-8 parts of phenol-aralkyl type curing agent, 2-8 parts of imidazole type curing agent, 0.1-0.5 parts of coupling agent, 0.3-1 part of release agent, 0.1-0.5 parts of colorant, and 80-87 parts of silica.

3. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 2, wherein The mass ratio of the phenol-aralkyl type curing agent to the imidazole type curing agent is (4-5):(3-4).

4. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 3, characterized in that, The epoxy equivalent of the o-cresol novolac epoxy resin is 180-220 g / eq.

5. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 4, wherein The epoxy equivalent of the dicyclopentadiene phenol type epoxy resin is 250-300 g / eq.

6. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 5, characterized in that, The hydroxyl equivalent of the phenol-aralkyl type curing agent is 150-250 g / eq.

7. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 6, wherein The melting point of the imidazole type curing agent is <100 °C.

8. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 7, wherein, The epoxy resin composition has at least one of the following properties: A. The curing time of the epoxy resin composition at 175 °C is ≤20 s; B. The curing time of the epoxy resin composition at 150 °C is ≤30 s; C. The curing time of the epoxy resin composition at 100 °C is ≤75 s.

9. The epoxy resin composition for low-temperature rapid-curing injection molding according to claim 8, wherein, The spiral flow length of the epoxy resin composition is ≥25 inch.

10. A method for preparing an epoxy resin composition for low-temperature rapid-curing injection molding according to any one of claims 1-9, characterized in that, By weight parts, the o-cresol novolac epoxy resin, dicyclopentadiene phenol type epoxy resin, phenol-aralkyl type curing agent, imidazole type curing agent, coupling agent, release agent, colorant, and silica are mixed and then successively passed through a low-temperature zone, a high-temperature mixing zone, and a medium-temperature zone to obtain the product.

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