High-thermal-conductivity epoxy resin composition and application thereof in TO-220F packaging

Abstract

The invention relates to the technical field of electronic packaging materials, in particular to a high-thermal-conductivity epoxy resin composition and application thereof in TO-220F packaging. The epoxy resin composition comprises the following raw materials in percentage by weight: 1-10% of epoxy resin, 3-10% of phenolic resin, 0.02-4% of curing accelerator, 0-8% of additive and the balance of inorganic filler. The inorganic filler at least comprises spherical crystalline silicon dioxide; the thermal conductivity of the epoxy resin composition is 2.0 W / m.K or more. The spherical crystalline silicon dioxide is added into the epoxy plastic packaging material, so that the electronic component packaging material disclosed by the invention shows excellent heat-conducting property. By means of the improvement, the heat dissipation requirement in a high-power application scene is met, the service life of electronic components is effectively prolonged, and the failure rate caused by overheating is reduced. And the obtained product can meet the use requirements of TO-220F packaging.

Description

Technical Field

[0001] The invention relates to the technical field of electronic packaging materials, and in particular to a high thermal conductivity epoxy resin composition and application thereof in TO-220F packaging. Background Art

[0002] In recent years, with the rapid advancement of science and technology and the growing demand for high-performance and high-reliability electronic components in various industries, fully encapsulated electronic components (such as TO-220F and TO-3PF series) have won wide recognition and application in many fields due to their excellent electrical insulation performance. Especially in industries such as automobile manufacturing, industrial automation control and high-end consumer product design, these components have become the key factors in improving the overall performance and service life of products with their excellent packaging technology and stable working performance.

[0003] However, with the continuous deepening and expansion of technology applications, especially in the face of certain application scenarios with high power density, high efficiency conversion and harsh working environment, the limitations of traditional epoxy molding materials in thermal conductivity have gradually emerged. In these scenarios, effectively managing and efficiently dissipating heat to ensure that electronic components can continue to operate stably without performance degradation or damage due to overheating has become a technical challenge that needs to be solved urgently. Therefore, the industry has put forward more stringent thermal conductivity requirements for epoxy molding materials used in fully encapsulated electronic components.

[0004] Chinese patent application CN118240515A discloses a resin composition for electronic packaging, which uses a modified resin with a specific structure to effectively reduce the stress of the entire system. When combined with a suitable stress release agent, it can not only significantly reduce the modulus and stress level of the entire resin composition, but also has little effect on various properties such as water absorption, Tg and bonding. The resin composition maintains ultra-low stress at both high and low temperatures, and does not produce cracking, delamination and other failures. Chinese patent application CN110066491A discloses an epoxy resin composition, its preparation method and use. It uses silicon dioxide A, silicon dioxide B, and silicon dioxide C as crystalline silicon dioxide, and silicon dioxide D is molten silicon dioxide. The obtained epoxy resin composition has the advantages of strong applicability, low cost, low water absorption, high fluidity, high reliability, etc. The obtained product has the characteristics of no pore defects, no delamination, good filling, etc. after packaging, which improves the yield rate of rectifier bridge type component packaging. Chinese patent CN114685938A discloses an epoxy resin composition for electronic packaging and a preparation method thereof, wherein the fillers include spherical alumina and crystalline silica to improve the thermal conductivity of the material; however, alumina is expensive and has high implementation costs, and is not suitable for TO-220F packaging.

[0005] However, these existing technologies have not effectively improved the thermal conductivity of epoxy resin molding compounds, and there is an urgent need to provide an epoxy resin product with high thermal conductivity that can meet the requirements of TO-220F packaging. Summary of the invention

[0006] In order to solve the technical problem that the thermal conductivity of existing epoxy molding compounds is limited, while TO-220F packaging has high requirements on the thermal conductivity of materials, and the two cannot match each other, the first aspect of the present invention provides a high thermal conductivity epoxy resin composition. The raw materials of the epoxy resin composition include, by weight percentage: 1-10% epoxy resin, 3-10% phenolic resin, 0.02-4% curing accelerator, 0-8% additive, and inorganic filler to make up the balance.

[0007] Preferably, the inorganic filler includes at least spherical crystalline silica.

[0008] More preferably, the mass ratio of the epoxy resin to the inorganic filler is (2-10): (75-90).

[0009] Preferably, the particle size D50 of the spherical crystalline silica is 15-40 μm, more preferably 20 μm.

[0010] Preferably, the maximum particle size of the spherical crystalline silica is 50-90 μm, and more preferably 75 μm.

[0011] Preferably, the amount of the spherical crystalline silica added to the epoxy resin composition is 40-90 wt %; more preferably 70-88 wt %.

[0012] The present invention introduces spherical crystalline silica into the epoxy resin composition, which significantly improves the thermal conductivity of the material. It is speculated that the unique crystal structure of spherical crystalline silica enables heat to be efficiently transferred inside the material, thereby significantly improving the thermal conductivity of the entire packaging material. When this high thermal conductivity filler is evenly dispersed in the epoxy molding material, an efficient heat conduction network is formed, so that heat can be quickly conducted from the inside of the component to the external environment. The particle size D50 value of the spherical crystalline silica is further limited to 15-40μm, and the maximum particle size is 50-90μm, which can improve the microstructure of the epoxy molding material. During the filling process, these tiny spherical particles can fill the gaps in the material, reduce thermal resistance, and further improve the efficiency of heat conduction. At the same time, their presence can also suppress the stress accumulation inside the material and improve the processing performance of the epoxy resin composition.

[0013] Preferably, the inorganic filler may further include conventional crystalline silica, and the mass ratio of the conventional crystalline silica to the spherical crystalline silica is (1.2-2):1.

[0014] Note: The main difference between conventional crystalline silica and spherical crystalline silica in the present invention is that conventional crystalline silica has edges and corners in shape, while spherical crystalline silica is physically processed and polished to remove the edges and corners.

[0015] More preferably, the particle size D50 value of the conventional crystalline silica is 15-40 μm; further preferably 25-35 μm.

[0016] More preferably, the maximum particle size of the conventional crystalline silica is 100-240 μm; further preferably 160-200 μm.

[0017] The conventional crystalline silica and spherical crystalline silica are commercially available, for example, from Jiangsu Lianrui New Materials Co., Ltd.

[0018] Preferably, the structural formula of the epoxy resin is a combination of one or more compounds shown in the following formula I and formula II;

[0019] Formula I: wherein n is selected from 1, 2 or 3;

[0020] Formula II: wherein m is selected from 1, 2 or 3.

[0021] The compounds represented by Formula I and Formula II can be commercially available, including but not limited to the following sources.

[0022] Formula I: Supplier: Changchun Artificial Resin Factory, product model: CNE-195LL.

[0023] Formula II: Supplier: DIC Epoxy (Malaysia) Sdn. Bhd., product model: HP-7200.

[0024] More preferably, the epoxy resin comprises at least the compound represented by Formula II, and the compound represented by Formula II is added in an amount of 2-6.5 wt % in the epoxy resin composition.

[0025] Further preferably, the epoxy resin comprises a combination of compounds represented by Formula I and Formula II.

[0026] Preferably, the compound represented by formula I is added to the epoxy resin composition in an amount of 1-7 wt %.

[0027] Preferably, the structural formula of the phenolic resin is: wherein x is selected from 1, 2 or 3.

[0028] The phenolic resin can be commercially available, including but not limited to: Shandong Shengquan New Materials Co., Ltd., product model PF8013. The present invention preferably uses a high-viscosity phenolic resin to meet the processing requirements of TO-220F and avoid the problem of pores during the processing of the product.

[0029] Preferably, the phenolic resin is added in an amount of 4-7 wt % in the epoxy resin composition.

[0030] The present invention selects epoxy resin and phenolic resin with specific structures, which can be well matched with silica fillers with specific shapes and particle sizes, so that the thermal conductivity of the finally obtained epoxy resin composition is increased to above 2.0 W / m·K.

[0031] The curing accelerator can be listed as triphenylphosphine-benzoquinone adduct, triphenylphosphine, imidazole compounds, etc.; preferably, the curing accelerator includes at least one of triphenylphosphine-benzoquinone adduct and triphenylphosphine; more preferably, the curing accelerator includes triphenylphosphine-benzoquinone adduct.

[0032] The present invention can flexibly select the type of additives according to the downstream packaging needs. The additives can be listed as coupling agents, color powders, release agents, toughening agents, stress modifiers, flame retardants, lubricants, antistatic agents, ultraviolet absorbers, etc.

[0033] Preferably, the additive includes at least one of a coupling agent, a color powder, and a release agent; and the additive is added in an amount of 0.1-3 wt % in the epoxy resin composition.

[0034] In order to further take into account the high thermal conductivity and processing performance of the epoxy resin composition, more preferably, the additives include a coupling agent, a color powder and a release agent, and the mass ratio is 1: (1-1.5): (1.4-2).

[0035] Preferably, the coupling agent includes one or more of 3-(glycidyloxypropyl)trimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and vinyltrimethoxysilane.

[0036] More preferably, the coupling agent includes a combination of one or more of 3-(glycidyloxypropyl)trimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane.

[0037] Further preferably, the coupling agent includes 3-(glycidyloxypropyl)trimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane in a weight ratio of 1:1:1.

[0038] The release agent may be exemplified by natural wax or synthetic wax.

[0039] Preferably, the natural wax includes one or more combinations of carnauba wax, candelilla wax, wood wax, beeswax, paraffin wax and derivatives thereof.

[0040] Preferably, the synthetic wax includes one or more combinations of polyethylene wax, polypropylene wax, polyester wax and polyurethane wax.

[0041] More preferably, the release agent comprises natural wax, and further preferably comprises carnauba wax.

[0042] In some embodiments, the toner may be carbon black.

[0043] In some preferred embodiments, the thermal conductivity of the epoxy resin composition is greater than 2.0 W / m·K.

[0044] More preferably, the epoxy resin composition satisfies one or more of the following conditions a to c:

[0045] a. Thermal conductivity is 2.2-2.5W / m·K;

[0046] b. The gelation time is 20-40 seconds, and the test condition is 175°C;

[0047] c. The spiral flow length is 10-20 inches, and the test condition is curing at 175°C for 90 seconds.

[0048] More preferably, the epoxy resin composition satisfies conditions a to c simultaneously.

[0049] A second aspect of the present invention provides a method for preparing a high thermal conductive epoxy resin composition, the preparation steps of the epoxy resin composition comprising:

[0050] 1) Grinding the epoxy resin and phenolic resin respectively, packaging the powders, sealing them and setting them aside;

[0051] 2) Mix the raw materials except epoxy resin and phenolic resin, add the crushed epoxy resin and phenolic resin, and mix well;

[0052] 3) The material obtained in step 2) is mixed and extruded, and cooled to obtain an epoxy resin composition product.

[0053] In some preferred embodiments, the preparation steps of the epoxy resin composition include:

[0054] 1) Under low temperature conditions, the epoxy resin and the phenolic resin are crushed separately, the powders are packaged, sealed, and stored at low temperature for later use;

[0055] 2) adding inorganic fillers, curing accelerators and additives to a high-speed mixer in batches under low temperature conditions and mixing them, and then adding the crushed epoxy resin and phenolic resin and mixing them evenly;

[0056] 3) The material obtained in step 2) is transferred to an extruder for mixing and extrusion, and then pulverized after cooling to obtain an epoxy resin composition product.

[0057] Preferably, the step 1) is performed by using a resin crusher for crushing.

[0058] Preferably, the low temperature conditions of step 1) and step 2) are both below 25°C, more preferably 10-20°C, most preferably 15°C.

[0059] In some embodiments, the extruder comprises a single-screw extruder or a twin-screw extruder; preferably, the extruder is a twin-screw extruder.

[0060] Preferably, the extrusion temperature is 90-120°C, more preferably 95-105°C.

[0061] Preferably, the epoxy resin composition product is placed in a low temperature environment below 5° C. and sealed for storage.

[0062] A third aspect of the present invention provides an application of a high thermal conductivity epoxy resin composition, wherein the epoxy resin composition is applied in the field of electronic packaging, and is particularly suitable for TO-220F packaging.

[0063] The TO-220F package is a plug-in package designed for high-power transistors, small and medium-scale integrated circuits, etc. The metal sheet (heat sink) of the TO-220F package is in close contact with the internal structure of the device, which can effectively conduct the heat generated inside to the external environment. This design enables the device to maintain a low operating temperature in high-power application scenarios, thereby improving its stability and reliability. However, the current TO-220F still has a certain gap in heat dissipation performance compared to the TO-220AC package. The present invention adds spherical crystalline silica to the epoxy plastic packaging material to give the packaging material excellent thermal conductivity. This improvement not only meets the heat dissipation requirements in high-power application scenarios, but also effectively extends the service life of electronic components, reduces the failure rate caused by overheating, and has broad application prospects.

[0064] Beneficial effects:

[0065] The present invention provides a high thermal conductivity epoxy resin composition and a preparation method thereof and application in TO-220F packaging, which has the following advantages:

[0066] (1) Improved thermal conductivity: By adding spherical crystalline silica to the epoxy molding material, the electronic component packaging material of the present invention exhibits excellent thermal conductivity. This improvement not only meets the heat dissipation requirements in high-power application scenarios, but also effectively extends the service life of electronic components and reduces the failure rate caused by overheating.

[0067] (2) Optimizing material structure: The present invention optimizes the internal structure of the epoxy molding material by precisely controlling the addition amount and dispersion of spherical crystalline silicon dioxide. This optimization enables the material to have good mechanical properties and processing properties while maintaining high thermal conductivity, providing more convenience for the manufacture and packaging of electronic components.

[0068] (3) Improve production efficiency: Since the epoxy molding material with spherical crystalline silica has excellent fluidity and formability, it can significantly improve the packaging efficiency of electronic components in the actual production process. This not only reduces production costs, but also shortens the product production cycle, which has positive economic benefits.

[0069] (4) Expanding application areas: The electronic component packaging material of the present invention has shown broad application prospects in multiple fields such as automobiles, industry, and consumer products due to its excellent thermal conductivity and insulation properties. It is particularly suitable for high-power and high-heat dissipation demand scenarios such as TO-220F packaging. This material will play a more important role and promote the rapid development of related industries.

[0070] (5) Meeting mass production requirements: The present invention can significantly improve the thermal conductivity of the material by compounding specific raw materials such as epoxy resin, phenolic resin and spherical crystalline silica; the raw materials are easily available and the formula is simple, the process is simple, and the operation is simple, which can meet the requirements of mass production. DETAILED DESCRIPTION

[0071] Note: Unless otherwise specified, the raw materials used in the present invention are all commercially available.

[0072] Example

[0073] Examples 1-3

[0074] Examples 1-3 respectively provide a high thermal conductivity epoxy resin composition, a preparation method thereof, and an application thereof in TO-220F packaging.

[0075] The formula of the epoxy resin composition is shown in Table 1; the values ​​in Table 1 are the amounts of raw materials added, in units of weight percentage.

[0076] Table 1 Formula of epoxy resin composition of Examples 1-3

[0077]

[0078]

[0079] Note: / in Table 1 means not added.

[0080] The sources of the raw materials in Table 1 are as follows.

[0081] Formula I: Supplier: Changchun Artificial Resin Factory, product model: CNE-195LL.

[0082] Formula II: Supplier: DIC Epoxy (Malaysia) Sdn. Bhd., product model: HP-7200.

[0083] Phenolic resin: Shandong Shengquan New Materials Co., Ltd., product model PF8013.

[0084] Spherical crystalline silica: maximum particle size is 75μm, particle size D50 value is 20μm, specific surface area is 2.5m 2 / g; Sourced from Jiangsu Lianrui New Materials Co., Ltd.

[0085] Conventional crystalline silica: maximum particle size 180um, particle size D50 value 29um; sourced from Jiangsu Lianrui New Materials Co., Ltd.

[0086] Spherical fused silica: maximum particle size 75um, particle size D50 value 20um; sourced from Jiangsu Lianrui New Materials Co., Ltd.

[0087] Triphenylphosphine-benzoquinone adduct: specifically triphenylphosphine-1,4-benzoquinone adduct, CAS number is 5405-63-0.

[0088] Carnauba wax: Supplier: NIKKO FINE Co., Ltd., product model: Nikko carnauba.

[0089] Carbon black: Supplier: Mitsubishi Chemical Corporation, product model: MA600.

[0090] The preparation steps of the epoxy resin composition include:

[0091] 1) Use a resin crusher to crush the epoxy resin and phenolic resin separately, and control the operating temperature to 15°C; then pack and seal them, and store them at low temperature for future use;

[0092] 2) Add inorganic filler, curing accelerator, coupling agent, release agent and color powder to a high-speed mixer in batches and mix them. The operating temperature is controlled at 15° C. Then add the crushed epoxy resin and phenolic resin and mix them evenly.

[0093] 3) The material obtained in step 2) is transferred to a twin-screw extruder, mixed and extruded at 100° C., and then pulverized after cooling to obtain an epoxy resin composition product.

[0094] The obtained epoxy resin composition is stored at low temperature (below 5° C.) for future use.

[0095] Performance Testing Methods

[0096] With reference to the GB / T 40564-2021 method, the gelation time, spiral flow length and thermal conductivity of the epoxy resin compositions prepared in Examples 1-3 were tested. The test results are shown in Table 2.

[0097] The spiral flow length was tested under the conditions of curing at 175°C for 90 seconds, and the gelation time was tested under the conditions of 175°C.

[0098] Performance Test Results

[0099] The test results of the epoxy resin compositions prepared in Examples 1-3 are shown in Table 2.

[0100] Table 2 Performance test results of epoxy resin compositions of Examples 1-3

[0101] Example 1 Example 2 Example 3 Gel time (sec) 30 29 28 Spiral flow length (inch) 17 15 14 Thermal conductivity (W / m·K) 2.0 2.2 2.4

[0102] As shown in the data in Table 2, using spherical crystalline silica instead of spherical fused silica in the epoxy resin composition can effectively improve the thermal conductivity of the epoxy molding compound; selecting the addition amount of spherical crystalline silica to be 86% can further improve the thermal conductivity of the material on the basis of appropriate gelation time and spiral flow length. The thermal conductivity of the epoxy resin composition obtained in Examples 2 and 3 of the present invention is higher than that of most similar products in the same industry, and can meet the use requirements of TO-220F packaging.

Claims

1. A high thermal conductivity epoxy resin composition, characterized in that: The raw materials of the epoxy resin composition include, by weight percentage: 1-10% epoxy resin, 3-10% phenolic resin, 0.02-4% curing accelerator, 0-8% additive, and the balance is supplemented by inorganic filler; The inorganic filler comprises at least spherical crystalline silica; The epoxy resin composition has a thermal conductivity of 2.0 W / m·K or more.

2. The high thermal conductivity epoxy resin composition according to claim 1, characterized in that: The particle size D50 value of the spherical crystalline silica is 15-40 μm, and the maximum particle size is 50-90 μm.

3. The high thermal conductivity epoxy resin composition according to claim 2, characterized in that: The spherical crystalline silica is added in an amount of 40-90 wt % in the epoxy resin composition.

4. The high thermal conductive epoxy resin composition according to claim 1, characterized in that: The structural formula of the epoxy resin is a combination of one or more compounds shown in the following formula I and formula II; Formula I: wherein n is selected from 1, 2 or 3; Formula II: wherein m is selected from 1, 2 or 3.

5. The high thermal conductivity epoxy resin composition according to claim 4, characterized in that: The epoxy resin comprises a compound of compounds represented by formula I and formula II.

6. The high thermal conductive epoxy resin composition according to claim 4, characterized in that: The structural formula of the phenolic resin is: wherein x is selected from 1, 2 or 3.

7. The high thermal conductive epoxy resin composition according to claim 1, characterized in that: The additives include coupling agent, color powder and release agent, with a mass ratio of 1: (1-1.5): (1.4-2); The additive is added in an amount of 0.5-3 wt % in the epoxy resin composition.

8. The high thermal conductive epoxy resin composition according to claim 7, characterized in that: The epoxy resin composition satisfies one or more of the following conditions a to c: a. Thermal conductivity is 2.2-2.5W / m·K; b. The gelation time is 20-40 seconds, and the test condition is 175°C; c. The spiral flow length is 10-20 inches, and the test condition is curing at 175°C for 90 seconds.

9. A method for preparing a high thermal conductive epoxy resin composition according to any one of claims 1 to 8, characterized in that: The preparation steps include: 1) Under low temperature conditions, the epoxy resin and the phenolic resin are crushed respectively, and the powders are packaged, sealed, and set aside; 2) Mixing raw materials except epoxy resin and phenolic resin under low temperature, adding crushed epoxy resin and phenolic resin, and mixing evenly; 3) mixing and extruding the material obtained in step 2), and cooling to obtain an epoxy resin composition product; The low temperature conditions of step 1) and step 2) are both below 25°C.

10. Use of the high thermal conductivity epoxy resin composition according to any one of claims 1 to 8 in TO-220F packaging.

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