High-thermal-conductivity epoxy resin composition for packaging and preparation method of high-thermal-conductivity epoxy resin composition

Abstract

The epoxy resin composition is prepared from the following raw materials in parts by weight: 1 to 5 parts of epoxy resin, 1 to 3 parts of modified epoxy resin, 1 to 3 parts of a curing agent, 88 to 95 parts of heat-conducting filler, 0.5 to 1 part of a coupling agent, 0.5 to 1 part of a release agent, 0.1 to 0.5 part of a low stress agent and 0.1 to 0.5 part of a coloring agent. The tertiary amine-terminated hyperbranched polymer curing agent is introduced into an epoxy resin system, so that the resin composition still has a good mixing and forming effect after the use amount of the heat-conducting filler is increased. The heat-conducting fillers with different particle sizes of 25 microns, 55 microns and 75 microns are matched for use, so that the heat-conducting property can be greatly improved on the basis of meeting the packaging and mixing requirements.

Description

Technical Field

[0001] The present invention relates to the field of chip packaging, and in particular to an epoxy resin composition for high thermal conductivity packaging and a preparation method thereof. Background Art

[0002] With the development of technology, electronic products have a higher degree of integration, and miniaturized and lightweight electronic products are increasingly widely used. In order to make the performance of electronic products more stable, it is necessary to improve the thermal conductivity of electronic product chip packaging. As the amount of thermal conductive filler used in the packaging resin increases, the thermal conductivity improves. However, when a certain amount is added, the thermal conductivity is not significantly improved after the addition of thermal conductive filler. If a new type of thermal conductive filler is replaced, the cost will increase. Therefore, it is very important to develop an electronic packaging material with good thermal conductivity and high cost performance.

[0003] Chinese invention patent CN117106400A discloses a high thermal conductivity epoxy resin thermal conductive adhesive for electronic packaging and its preparation method. By using two spherical alumina powders with different particle sizes, more thermal conductive channels can be constructed. Compared with epoxy resin adhesives with spherical alumina powders of a single particle size, it has lower viscosity, higher thermal conductivity and better thermal conductivity. However, the glass transition temperature is low and the stability is poor at high temperatures. Chinese invention patent CN113930050B discloses a high thermal conductivity low viscosity epoxy molding compound and its preparation method. After spherical alumina and flaky alumina are assembled into hybrid fillers by chemical bonding according to a certain component ratio, they are dispersed, mixed, crushed and molded with an epoxy molding compound mixture at high speed. The obtained epoxy resin molding compound has high thermal conductivity and low internal stress, and the spiral flow length is not less than 50 inches, but the bonding force is low and the packaging effect is poor. Summary of the invention

[0004] In order to develop an electronic packaging material with good thermal conductivity and high cost performance, the first aspect of the present invention provides an epoxy resin composition for high thermal conductivity packaging. The preparation raw materials include, by weight: 1-5 parts of epoxy resin, 1-3 parts of modified epoxy resin, 1-3 parts of curing agent, 88-95 parts of thermal conductive filler, 0.5-1 part of coupling agent, 0.5-1 part of release agent, 0.1-0.5 part of low stress agent, and 0.1-0.5 part of colorant.

[0005] As a preferred embodiment, the chemical structure of the epoxy resin is as follows:

[0006] As a preferred embodiment, the modified epoxy resin is a phenolic modified epoxy resin, and the epoxy equivalent of the phenolic modified epoxy resin is 190-200 g / eq.

[0007] As a preferred embodiment, the epoxy equivalent of the phenolic modified epoxy resin is 198 g / eq.

[0008] As a preferred embodiment, the curing agent includes at least one of an amine curing agent and / or a phenolic curing agent, and the phenolic curing agent includes at least a biphenyl phenolic curing agent.

[0009] As a preferred embodiment, the phenolic curing agent further comprises curing agent II, and the structural formula of the curing agent II is

[0010] As a preferred embodiment, the amine curing agent is a terminal tertiary amine curing agent, and the curing temperature of the terminal tertiary amine curing agent is 70-90° C. and the curing time is 30-60 min.

[0011] As a preferred embodiment, the amine curing agent is a terminal tertiary amine curing agent, and the curing temperature of the terminal tertiary amine curing agent is 80° C. and the curing time is 40-60 minutes.

[0012] As a preferred embodiment, the weight ratio of the amine curing agent to the phenolic curing agent is (5-10):1.

[0013] As a preferred embodiment, the weight ratio of the amine curing agent to the phenolic curing agent is (6-8):1.

[0014] As a preferred embodiment, the weight ratio of the amine curing agent to the phenolic curing agent is 7:1.

[0015] The inventors found during the experiment that by introducing a terminal tertiary amine hyperbranched polymer curing agent into the epoxy resin system, the resin composition can still have a good mixing and molding effect after the amount of thermal conductive filler added is increased. The possible reason is that the terminal tertiary amine hyperbranched polymer curing agent can react and modify with the epoxy resin, improve the toughness of the epoxy resin, optimize the wrapping adhesion of the epoxy resin, and achieve mixing and molding. However, if the particle size of the thermal conductive filler is too small, its compaction density is high, which is not conducive to the wrapping of the epoxy resin system and easily causes mixing failure.

[0016] As a preferred embodiment, the thermally conductive filler includes at least one of silicon dioxide, aluminum oxide and titanium dioxide.

[0017] As a preferred implementation, the thermally conductive filler is alumina.

[0018] As a preferred embodiment, the particle size of the aluminum oxide is 20-80 μm.

[0019] As a preferred embodiment, the aluminum oxide has a particle size combination of 20-30 μm, 50-60 μm, and 70-80 μm.

[0020] As a preferred embodiment, the aluminum oxide has a particle size combination of 25 μm, 55 μm, and 75 μm.

[0021] As a preferred embodiment, the aluminum oxide has a particle size combination of 20-30 μm and 70-80 μm.

[0022] As a preferred embodiment, the aluminum oxide has a particle size combination of 25 μm and 75 μm.

[0023] As a preferred embodiment, the aluminum oxide has a particle size combination of 20-30 μm and 50-60 μm.

[0024] As a preferred embodiment, the aluminum oxide has a particle size combination of 25 μm and 55 μm.

[0025] As a preferred embodiment, the weight ratio of the aluminum oxide with a particle size of 20-30 μm, 50-60 μm, and 70-80 μm is (20-40): (20-40): (20-40).

[0026] As a preferred embodiment, the weight ratio of the aluminum oxide with particle sizes of 20-30 μm, 50-60 μm, and 70-80 μm is 31:30:32.

[0027] As a preferred embodiment, the weight ratio of the aluminum oxide with a particle size of 20-30 μm and 70-80 μm is (20-40): (50-70).

[0028] As a preferred embodiment, the weight ratio of the aluminum oxide with a particle size of 20-30 μm and 70-80 μm is 31:62.

[0029] As a preferred embodiment, the weight ratio of the aluminum oxide with a particle size of 20-30 μm and 50-60 μm is (20-40): (50-70).

[0030] As a preferred embodiment, the weight ratio of the aluminum oxide with a particle size of 20-30 μm and 50-60 μm is 31:62.

[0031] The inventors further discovered that the use of thermally conductive fillers with different particle sizes of 25 μm, 55 μm, and 75 μm can significantly improve the thermal conductivity on the basis of meeting the packaging and mixing requirements. The reason may be that thermally conductive fillers with different particle sizes can be interspersed and filled, which increases the packing density of the thermally conductive fillers and never achieves a good thermal conductivity effect. However, if only small-particle-sized thermally conductive fillers are used, the skeleton support of large-particle-sized fillers is lacking, and the stress effect of the resin composition will decrease, which is not conducive to mixing and molding. If only large-particle-sized thermally conductive fillers are used, there will be gaps between the fillers, which is not conducive to the optimization of thermal conductivity.

[0032] As a preferred embodiment, the alumina is spherical alumina.

[0033] The coupling agent is a silane coupling agent, preferably, the silane coupling agent is γ-glycidyloxypropyltrimethoxysilane. The low stress agent is propylene elastomer POE. The release agent includes but is not limited to polyethylene wax; the colorant includes but is not limited to carbon black.

[0034] A second aspect of the present invention provides a method for preparing an epoxy resin composition for high thermal conductivity packaging, comprising the following steps:

[0035] S1: epoxy resin, modified epoxy resin, curing agent, thermal conductive filler, coupling agent, release agent, low stress agent and colorant are mixed uniformly according to weight, placed in a mixer and kneaded at 120-130° C. for 5-10 minutes, and discharged;

[0036] S2 is cooled at room temperature and crushed to 1-3 mm to obtain crushed material;

[0037] S3 compacts the crushed material into a compacted shape and packages it for discharge.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The epoxy resin composition for high thermal conductivity packaging of the present invention can still have a good mixing and molding effect after the amount of thermal conductive filler used is increased by introducing a terminal tertiary amine hyperbranched polymer curing agent into the epoxy resin system.

[0040] (2) The epoxy resin composition for high thermal conductivity packaging of the present invention uses thermal conductive fillers with different particle sizes of 25 μm, 55 μm, and 75 μm, which can achieve a significant improvement in thermal conductivity while meeting packaging and mixing requirements.

[0041] (3) The epoxy resin composition for high thermal conductivity packaging of the present invention introduces 93% by mass of thermal conductive filler, which improves the thermal conductivity of the epoxy resin composition without affecting the stress and packaging performance of the epoxy resin composition.

[0042] (4) The epoxy resin composition for high thermal conductivity packaging of the present invention uses spherical alumina of different particle sizes as thermal conductive filler, achieving a thermal conductivity of 5W without affecting fluidity and mixing and molding effects.

[0043] (5) The high thermal conductivity packaging epoxy resin composition of the present invention can be applied to the packaging of electronic products with high heat dissipation requirements, such as QFN packaging, DIP packaging, and FC packaging. DETAILED DESCRIPTION

[0044] A high thermal conductivity epoxy resin composition for packaging, the raw materials for preparation are measured in parts by weight, as shown in the following Table 1-2.

[0045] Table 1

[0046]

[0047]

[0048] Table 2

[0049]

[0050]

[0051] The chemical structure of the epoxy resin is as follows: Purchased from DIC, brand HP-7200.

[0052] The modified epoxy resin is a phenolic modified epoxy resin with an epoxy equivalent of 198 g / eq, purchased from Changchun, Taiwan, China, with a brand name of CNE 195LL.

[0053] The structural formula of the curing agent II is Purchased from Shengquan, Shandong, China, brand name PF-8011.

[0054] The biphenyl phenolic curing agent was purchased from Hengfeng, Shanghai, China, with the brand name ResiCare 3900.

[0055] The terminal tertiary amine curing agent has a curing temperature of 80° C. and a curing time of 60 min. It is purchased from Shanghai Wujing Chemical Industry with a brand name of QNP1-4085.

[0056] The γ-glycidyl ether oxypropyl propyl trimethoxy silane was purchased from Ziyue Chemical with the model number KH-560.

[0057] The propylene-based elastomer POE is purchased from ExxonMobil with the brand name POE 3588FL.

[0058] The release agent is polyethylene wax purchased from Hebei Tianyu Chemical Co., Ltd., brand: TY-113.

[0059] The colorant is carbon black.

[0060] 25 μm alumina was purchased from Electrochemical with the brand name DAD-023; 55 μm alumina was purchased from Electrochemical with the brand name DAD-057; and 75 μm alumina was purchased from Electrochemical with the brand name DAD-072.

[0061] A method for preparing an epoxy resin composition for high thermal conductivity packaging comprises the following steps:

[0062] S1: epoxy resin, modified epoxy resin, curing agent, thermal conductive filler, coupling agent, release agent, low stress agent and colorant are mixed uniformly according to weight, placed in a mixer and mixed at 125° C. for 10 minutes, and discharged;

[0063] S2 is cooled at room temperature and crushed to 1-3 mm to obtain crushed material;

[0064] S3 compacts the crushed material into a compacted shape and packages it for discharge.

[0065] Performance Testing

[0066] 1. Curing time: Raise the temperature of the hot plate to 175°C and maintain ±1°C. Place 0.5-1.5g of sample on the hot plate and press it into a 6cm 2 -10cm 2 Thin slice, when the sample melts and the surface of the melt becomes shiny, press the stopwatch to start timing, scrape the sample continuously with a flat spatula and observe, or stir the sample continuously with a needle-shaped stirring rod and observe. The end point is when the sample changes from a molten state to a gel state, then stop timing and read the required time, which is the gelation time of the sample.

[0067] 2. Spiral flow length: When the mold temperature is constant at 175°C, weigh 15-25g of powdered sample and pour it into the mold cavity for injection molding. Turn it in and start timing. After the mold is automatically opened, remove the mold and open it to read the longest continuous point length.

[0068] 3. Glass transition temperature: TMA: Install the sample on the TMA sample stage, with 20℃ as the starting temperature, heating rate of 10℃ / min, and end temperature of 220℃. After scanning, the TMA test curve is obtained. Draw tangent lines above and below the transition temperature, and the temperature at the intersection of the two tangent lines is the glass transition temperature (Tg)

[0069] 4. Thermal expansion coefficient: TMA: Install the sample on the TMA sample table, with 20℃ as the starting temperature, heating rate of 10℃ / min, and ending temperature of 220℃. After scanning, the TMA test curve is obtained, and the thermal expansion coefficient is obtained from the equipment readings.

[0070] 5. Molding shrinkage: Inject the epoxy molding compound into a sample of 120mm×15mm×10mm. After injection molding, measure the difference between the sample and the mold.

[0071] 6. Thermal conductivity: Tested according to GB / T3139-2005 standard.

[0072] 7. Flexural modulus 25℃: tested according to GB / T3139-2005 standard.

[0073] 8. Bending strength at 25°C: tested according to GB / T3139-2005 standard.

[0074] The test results are shown in Table 3.

[0075] Table 3

[0076]

[0078] Note: Mixing of Example 4 failed and performance testing could not be performed.

[0079] Conclusion: The alumina content of Examples 1-3 is 90%, and the thermal conductivity is poor, only 3W; the alumina content of Example 4 is increased to 93%, and the inappropriate particle size leads to mixing failure; the alumina content of Example 5 is increased to 93%, the particle size is 55μm, and the thermal conductivity is not greatly improved, the alumina content of Example 6 is increased to 93%, the particle size is 75μm, and the thermal conductivity is not greatly improved, the alumina content of Example 7 is increased to 93%, and the combination of 25μm+55μm can meet the requirements; the alumina content of Example 8 is increased to 93%, and the combination of 25μm+75μm can meet the requirements; the alumina content of Example 9 is increased to 93%, and the thermal conductivity is not greatly improved by the combination of 55μm+75μm, the alumina content of Example 10 is increased to 93%, and the combination of 25μm+55μm+75μm is adopted, and the thermal conductivity effect meets the requirements.

Claims

1. An epoxy resin composition for high thermal conductivity packaging, characterized in that: The raw materials for preparation include, by weight: 1-5 parts of epoxy resin, 1-3 parts of modified epoxy resin, 1-3 parts of curing agent, 88-95 parts of thermal conductive filler, 0.5-1 parts of coupling agent, 0.5-1 parts of release agent, 0.1-0.5 parts of low stress agent and 0.1-0.5 parts of colorant.

2. The epoxy resin composition for high thermal conductivity packaging according to claim 1, characterized in that: The modified epoxy resin is a phenolic modified epoxy resin, and the epoxy equivalent of the phenolic modified epoxy resin is 190-200 g / eq.

3. The epoxy resin composition for high thermal conductivity packaging according to claim 1, characterized in that: The curing agent includes at least one of an amine curing agent and / or a phenolic curing agent, and the phenolic curing agent includes at least a biphenyl phenolic curing agent.

4. The epoxy resin composition for high thermal conductivity packaging according to claim 3, characterized in that: The amine curing agent is a terminal tertiary amine curing agent, and the curing temperature of the terminal tertiary amine curing agent is 70-90° C. and the curing time is 30-60 minutes.

5. The epoxy resin composition for high thermal conductivity packaging according to claim 3, characterized in that: The weight ratio of the amine curing agent to the phenolic curing agent is (5-10):

1.

6. The epoxy resin composition for high thermal conductivity packaging according to claim 1, characterized in that: The thermally conductive filler includes at least one of silicon dioxide, aluminum oxide and titanium dioxide.

7. The epoxy resin composition for high thermal conductivity packaging according to claim 5, characterized in that: The particle size of the aluminum oxide is 20-80 μm.

8. The epoxy resin composition for high thermal conductivity packaging according to claim 5, characterized in that: The particle size of the aluminum oxide is selected from at least one of a combination of 20-30 μm, 50-60 μm, and 70-80 μm.

9. The epoxy resin composition for high thermal conductivity packaging according to claim 8, characterized in that: The weight ratio of the aluminum oxide with particle sizes of 20-30 μm, 50-60 μm, and 70-80 μm is (20-40): (20-40): (20-40).

10. A method for preparing the epoxy resin composition for high thermal conductivity packaging according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1: epoxy resin, modified epoxy resin, curing agent, thermal conductive filler, coupling agent, release agent, low stress agent and colorant are mixed uniformly according to weight, placed in a mixer and kneaded at 120-130° C. for 5-10 minutes, and discharged; S2 is cooled at room temperature and crushed to 1-3 mm to obtain crushed material; S3 compacts the crushed material into a compacted shape and packages it for discharge.

Images