An epoxy resin molding compound for C-Mold process and its preparation method and application

Abstract

This invention relates to the field of epoxy resin composition technology, specifically to an epoxy resin molding compound for the C-Mold process, its preparation method, and its application. By weight, it comprises at least the following raw materials: 1-4 parts of biphenyl-type epoxy resin, 1-2 parts of glycidyl amine epoxy resin, 1-2 parts of naphthyl ring-type epoxy resin, 3-6 parts of biphenyl-type phenolic resin, 85-88 parts of alumina, 1-3 parts of boron nitride, 0.2-1 parts of organosilicon, 0.5-3 parts of compounded resin, and 0.5-3 parts of additives. The compounded resin includes at least one of phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin. The additives include at least a catalyst, a release agent, a coupling agent, and a colorant, enabling the epoxy resin molding compound to simultaneously possess high fluidity, low stress, low coefficient of expansion, and high thermal conductivity, meeting the practical application requirements of the C-Mold process.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin composition technology, specifically to an epoxy resin molding compound for C-Mold process, its preparation method, and its application. Background Technology

[0002] Semiconductor chip packaging processes can be broadly categorized into sealing and molding methods. Sealing is primarily used in a few specialized fields, while molding, which utilizes epoxy resin molding compounds, is more common. Molding processes include transfer molding (T-Mold) and compression molding (C-Mold). T-Mold is an early molding packaging process where epoxy resin molding compound is melted to form a viscous flow state. Pressure is then forced through a plunger in the mold, causing the fluid to flow through multiple narrow paths to fill the cavity. After pressure holding and curing, the packaging is complete. C-Mold is a later-developed molding packaging process where epoxy resin molding compound is directly and uniformly placed into the mold, melted, and then the mold is closed to fill the cavity. After pressure holding and curing, the packaging is complete. As the number of chip layers increases and wire bonding becomes more complex, epoxy resin is difficult to spread evenly during the T-Mold process, which may lead to incomplete filling, voids, or wire breakage. In particular, in order to reduce costs, the size of the printed circuit board (PCB) or lead frame used as the carrier has increased, making T-Mold even more difficult.

[0003] C-Mold technology overcomes the limitations of T-Mold, but it places higher performance demands on epoxy molding compounds suitable for C-Mold. For example, larger and thinner package sizes can easily lead to package warpage. Furthermore, heat dissipation is a core issue that chip packaging needs to address. Therefore, it is necessary to develop low-stress, high-thermal-conductivity epoxy molding compounds for C-Mold. Currently, the primary considerations for epoxy molding compounds suitable for C-Mold are meeting process requirements and possessing low-stress characteristics, meaning that high requirements are placed on the flowability and low-stress properties of the epoxy molding compound. To improve chip heat dissipation, better thermal conductivity of epoxy molding compounds is beneficial for chip cooling. However, simply increasing the thermal conductivity of epoxy molding compounds, such as raising its thermal conductivity to above 3 W / (m·K), inevitably requires the addition of inorganic fillers with high thermal conductivity, which may affect the flowability and low stress properties of the epoxy molding compounds. For example, Chinese patent (publication number CN114685938 A) discloses an epoxy resin composition for electronic packaging and its preparation method, which improves the thermal conductivity of the composition by introducing spherical alumina and crystalline silica into the system. However, as the content of thermally conductive fillers in the system increases, the flowability and stress of the product are affected, failing to meet the actual application requirements of C-Mold. Therefore, it is difficult to make epoxy molding compounds simultaneously possess high flowability, low stress, low coefficient of expansion, and high thermal conductivity to meet the requirements of C-Mold processes. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides an epoxy resin molding compound for the C-Mold process. Through a thermally conductive filler, epoxy resin, compounded resin, and silicone system, the epoxy resin molding compound simultaneously possesses high fluidity, low stress, low coefficient of expansion, and high thermal conductivity, thus meeting the practical application requirements of the C-Mold process.

[0005] This invention provides an epoxy resin molding compound for C-Mold process, comprising, by weight, at least the following raw materials: 1-4 parts of biphenyl epoxy resin, 1-2 parts of glycidyl amine epoxy resin, 1-2 parts of naphthyl ring epoxy resin, 3-6 parts of biphenyl phenolic resin, 85-88 parts of alumina, 1-3 parts of boron nitride, 0.2-1 parts of organosilicon, 0.5-3 parts of compound resin, and 0.5-3 parts of additives; wherein the compound resin comprises at least one of phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin; and wherein the additives comprise at least a catalyst, a release agent, a coupling agent, and a colorant.

[0006] As a preferred technical solution, the compounded resin is a combination of phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin.

[0007] Preferably, the mass ratio of the phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin is (0.5-1):(0.5-1):(0.1-0.5).

[0008] The phenylmethane maleimide is designated BMI-2000 and is sourced from Daiwa Chemical Co., Ltd. of Japan; the CAS number of the bisphenol M cyanate is 127667-44-1 and is sourced from Hubei Kemaidi Chemical Co., Ltd.; the polyurethane polyol resin is designated DR-50 and is sourced from Yueyang Dongrun Chemical Co., Ltd.

[0009] As a preferred technical solution, the organosilicon is an organosilicon elastomer and / or epoxy-modified silicone oil.

[0010] Preferably, the organosilicon is a combination of organosilicon elastomer and epoxy-modified silicone oil.

[0011] Preferably, the mass ratio of the organosilicon elastomer to the epoxy-modified silicone oil is (0.1-0.5):(0.1-0.5).

[0012] The silicone elastomer is model EP-2720, sourced from Dow Corning, USA; the epoxy modified silicone oil is model DY-E701, sourced from Shandong Dayi Chemical Co., Ltd.

[0013] As a preferred technical solution, the additives, by weight, include at least 0.1-0.5 parts of catalyst, 0.1-0.5 parts of coupling agent, 0.1-0.5 parts of colorant, and 0.2-1 parts of release agent.

[0014] As a preferred technical solution, the epoxy resin molding compound for the C-Mold process, by weight, comprises at least the following raw materials: 2-3 parts of biphenyl epoxy resin, 1-1.5 parts of glycidyl amine epoxy resin, 1-1.5 parts of naphthyl ring epoxy resin, 3.5-4.5 parts of biphenyl phenolic resin, 85.5-87 parts of alumina, 1-3 parts of boron nitride, 0.2-0.5 parts of organosilicon, 1.5-3 parts of compound resin, 0.2-0.4 parts of catalyst, 0.3-0.5 parts of coupling agent, 0.2-0.3 parts of colorant, and 0.2-0.5 parts of release agent.

[0015] As a preferred technical solution, the mass ratio of the compounded resin to the total mass of biphenyl epoxy resin, glycidyl amine epoxy resin, and naphthyl ring epoxy resin is (1.8-2.5):(4-5), preferably (2-2.5):(4.5-5), and most preferably 2.2:4.8.

[0016] As a preferred technical solution, the biphenyl-type epoxy resin is a combination of crystalline biphenyl-type epoxy resin with an epoxy equivalent of 180-200 g / eq and biphenyl-phenol-type self-flame-retardant epoxy resin with an epoxy equivalent of 260-300 g / eq.

[0017] Preferably, the glycidylamine epoxy resin is a tetrafunctional glycidylamine epoxy resin, and the epoxy equivalent of the tetrafunctional glycidylamine epoxy resin is 100-120 g / eq.

[0018] Preferably, the epoxy equivalent of the naphthalene ring type epoxy resin is 140-204 g / eq.

[0019] As a preferred technical solution, the mass ratio of the crystalline biphenyl type epoxy resin, the biphenyl phenol type self-flame retardant epoxy resin, the glycidyl amine type epoxy resin, and the naphthyl ring type epoxy resin is (1.1-1.3):(1.1-1.3):(1.1-1.3):(1.1-1.3).

[0020] The crystalline biphenyl-type epoxy resin, model JX9000H, and the biphenyl phenol-type self-flame-retardant epoxy resin, model BPNE3501LL, are both sourced from Hunan Jiashengde Materials Technology Co., Ltd.; the tetrafunctional glycidylamine epoxy resin, model XB9721, is sourced from Guangzhou Yihuisheng Chemical Co., Ltd.; and the naphthalene ring-type epoxy resin, model HP4700, is sourced from Dai Nippon Ink Chemical Co., Ltd.

[0021] As a preferred technical solution, the biphenyl-type phenolic resin is model SH-5075, which is sourced from Shandong Shengquan New Material Co., Ltd.

[0022] As a preferred technical solution, the mass ratio of alumina to boron nitride is (85.5-87):(1-3).

[0023] As a preferred technical solution, the alumina is spherical alumina, model AX3-32, which is sourced from Nippon Steel Corporation of Japan.

[0024] As a preferred technical solution, the boron nitride is spherical boron nitride, model CFA 50M. * It originates from 3M in the United States.

[0025] As a preferred technical solution, the catalyst is triphenylphosphine and / or imidazole.

[0026] Preferably, the catalyst is a combination of triphenylphosphine and imidazole, wherein the mass ratio of triphenylphosphine to imidazole is (1.5-3):1.

[0027] As a preferred technical solution, the coupling agent is a silane coupling agent, model KH560, sourced from Xuanhao New Materials.

[0028] As a preferred technical solution, the colorant is carbon black, model MA100, which is sourced from Mitsubishi, Japan.

[0029] As a preferred technical solution, the release agent is oxidized polyethylene, model PE105, sourced from Qihong Holdings Co., Ltd.

[0030] As a preferred technical solution, the epoxy resin molding compound used in the C-Mold process has one or more of the following properties:

[0031] a. Spiral flow length, 175℃ > 50 inch;

[0032] b. Viscosity < 15 Pa·s;

[0033] c. Coefficient of thermal expansion at 40-80℃ < 7 ppm;

[0034] d. Coefficient of thermal expansion at 200-240℃ < 26 ppm;

[0035] e. Molding shrinkage rate < 0.010%;

[0036] f. Thermal conductivity > 3.5 W / (m·K).

[0037] This invention optimizes the inorganic filler to a combination of spherical alumina and spherical boron nitride, further controlling the addition amount of these two inorganic fillers in the epoxy resin molding compound system. This improves the thermal conductivity of the product to over 3.5 W / (m·K), ensuring the heat dissipation of the chip after C-Mold packaging. Inevitably, due to the addition of a large amount of spherical alumina to the system, the product's fluidity decreases, stress increases, and the coefficient of thermal expansion is high, failing to meet the requirements of the subsequent C-Mold process. During the research process, the inventors discovered that optimizing the epoxy resin system, including crystalline biphenyl-type epoxy resin, biphenylphenol-type self-flame-retardant epoxy resin, glycidylamine epoxy resin, and naphthalene ring-type epoxy resin, reduced the product's stress and coefficient of thermal expansion, but still could not meet the low-stress requirements of the C-Mold process. Furthermore, this invention introduces a compound resin composed of phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin into the epoxy resin molding compound system, and further controls the total mass ratio of the compound resin to biphenyl-type epoxy resin, glycidylamine epoxy resin, and naphthyl ring-type epoxy resin to be (1.8-2.5):(4-5), effectively reducing the molding shrinkage rate and coefficient of thermal expansion of the product. However, the product's flowability needs further improvement. Furthermore, this invention optimizes the system by introducing organosilicon elastomer and epoxy-modified silicone oil and controlling their addition amounts, in conjunction with epoxy resin and compound resin, to provide a product with the following characteristics: spiral flow length at 175℃ > 50 inch; viscosity < 15 Pa·s; coefficient of thermal expansion at 40-80℃ < 7 ppm; coefficient of thermal expansion at 200-240℃ < 26 ppm; molding shrinkage rate < 0.010%; and thermal conductivity > 3.5 W / (m·K).

[0038] Another aspect of the present invention provides a method for preparing epoxy resin molding compound for C-Mold process, comprising at least the following steps:

[0039] (1) Add biphenyl-type phenolic resin, phenylmethane maleimide and release agent to a heated mixing tank and stir at 130-160℃ for 20-60 min to obtain mixture 1;

[0040] (2) Add biphenyl epoxy resin, glycidyl amine epoxy resin, naphthalene ring epoxy resin, bisphenol M cyanate, polyurethane polyol resin, alumina, boron nitride, organosilicon, catalyst, coupling agent and colorant to a vertical stainless steel mixing tank and stir for 20-60 minutes to obtain mixture 2.

[0041] (3) Mixing material 2 is mixed by a twin-screw extruder, cooled and crushed to obtain epoxy resin molding compound for C-Mold process.

[0042] The third aspect of the present invention provides an application of epoxy resin molding compound for the C-Mold process, which is applied to the C-Mold process.

[0043] Beneficial effects

[0044] 1. This invention provides an epoxy resin molding compound for the C-Mold process. Through a thermally conductive filler, epoxy resin, compounded resin and organosilicon system, the epoxy resin molding compound simultaneously possesses high fluidity, low stress, low coefficient of expansion and high thermal conductivity, meeting the practical application requirements of the C-Mold process.

[0045] 2. This invention optimizes the inorganic filler to a combination of spherical alumina and spherical boron nitride, further controlling the addition amount of the two inorganic fillers in the epoxy resin molding compound system, thereby increasing the thermal conductivity of the product to over 3.5 W / (m·K) and ensuring the heat dissipation of the chip after C-Mold process packaging.

[0046] 3. This invention reduces the stress and coefficient of thermal expansion of the product by optimizing the epoxy resin system, including crystalline biphenyl epoxy resin, biphenyl phenol self-flame retardant epoxy resin, glycidyl amine epoxy resin, and naphthalene ring epoxy resin.

[0047] 4. This invention introduces a compound resin composed of phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin into the epoxy resin molding compound system, and further controls the total mass ratio of the compound resin to biphenyl epoxy resin, glycidyl amine epoxy resin, and naphthyl ring epoxy resin to (1.8-2.5):(4-5), which effectively reduces the molding shrinkage rate and coefficient of thermal expansion of the product. However, the flowability of the product needs to be further improved.

[0048] 5. This invention optimizes the system by introducing organosilicon elastomers and epoxy-modified silicone oils and controlling their addition amounts, combined with epoxy resin and compound resins, to provide products with the following characteristics: spiral flow length at 175℃ > 50 inch; viscosity < 15 Pa·s; coefficient of thermal expansion at 40-80℃ < 7 ppm; coefficient of thermal expansion at 200-240℃ < 26 ppm; molding shrinkage < 0.010%; and thermal conductivity > 3.5 W / (m·K). Detailed Implementation

[0049] In Tables 1 and 2: the phenylmethane maleimide is model BMI-2000, sourced from Daiwa Chemical Co., Ltd., Japan; the CAS number of the bisphenol M cyanate is 127667-44-1, sourced from Hubei Kemaidi Chemical Co., Ltd.; the polyurethane polyol resin is model DR-50, sourced from Yueyang Dongrun Chemical Co., Ltd.; the organosilicon elastomer is model EP-2720, sourced from Dow Corning, USA; the epoxy modified silicone oil is model DY-E701, sourced from Shandong Dayi Chemical Co., Ltd.; and the crystalline biphenyl epoxy resin is model JX9000H, a biphenyl-phenol type. The self-flame-retardant epoxy resin, model BPNE3501LL, is sourced from Hunan Jiashengde Materials Technology Co., Ltd.; the tetrafunctional glycidylamine epoxy resin, model XB9721, is sourced from Guangzhou Yihuisheng Chemical Co., Ltd.; the naphthalene ring epoxy resin, model HP4700, is sourced from Dai Nippon Ink Chemical Co., Ltd.; the biphenyl phenolic resin, model SH-5075, is sourced from Shandong Shengquan New Materials Co., Ltd.; the alumina is spherical alumina, model AX3-32, sourced from Nippon Steel Corporation; and the boron nitride is spherical boron nitride, model CFA 50M. * The silane coupling agent is KH560, sourced from Xuanhao New Materials; the carbon black is MA100, sourced from Mitsubishi, Japan; and the oxidized polyethylene is PE105, sourced from Qihong Holdings Co., Ltd.

[0050] Examples 1-4

[0051] Examples 1-4 of the present invention provide an epoxy resin molding compound for C-Mold process, the formulation of which is shown in Table 1 by weight.

[0052] Table 1

[0053]

[0054] Embodiments 1-4 of the present invention provide a method for preparing epoxy resin molding compound for C-Mold process, comprising the following steps:

[0055] (1) Add biphenyl-type phenolic resin, phenylmethane maleimide and oxidized polyethylene to a heated mixing tank and stir at 140°C for 30 min to obtain mixture 1;

[0056] (2) Add biphenyl epoxy resin, glycidyl amine epoxy resin, naphthalene ring epoxy resin, bisphenol M cyanate, polyurethane polyol resin, alumina, boron nitride, organosilicon elastomer, epoxy modified silicone oil, triphenylphosphine, imidazole, silane coupling agent and carbon black into a vertical stainless steel mixing tank and stir for 30 min to obtain mixture 2.

[0057] (3) Mixing material 2 is mixed by a twin-screw extruder. The temperature zones 1 to 4 are set to 20℃, 70℃, 110℃ and 70℃ respectively. After cooling and crushing, epoxy resin molding compound for C-Mold process is obtained.

[0058] Comparative Examples 1-7

[0059] Comparative Examples 1-7 of the present invention provide an epoxy resin molding compound, the formulation of which is shown in Table 2 by weight.

[0060] Table 2

[0061]

[0062] Comparative Examples 1-7 of the present invention, in another aspect, provide a method for preparing epoxy resin molding compound, comprising the following steps:

[0063] (1) Add biphenyl-type phenolic resin, phenylmethane maleimide and oxidized polyethylene to a heated mixing tank and stir at 140°C for 30 min to obtain mixture 1;

[0064] (2) Add biphenyl epoxy resin, glycidyl amine epoxy resin, naphthalene ring epoxy resin, bisphenol M cyanate, polyurethane polyol resin, alumina, boron nitride, organosilicon elastomer, epoxy modified silicone oil, triphenylphosphine, imidazole, silane coupling agent and carbon black into a vertical stainless steel mixing tank and stir for 30 min to obtain mixture 2.

[0065] (3) Mixing material 2 is mixed by a twin-screw extruder. The temperature zones 1 to 4 are set to 20℃, 70℃, 110℃ and 70℃ respectively. After cooling and crushing, epoxy resin molding compound for C-Mold process is obtained.

[0066] Performance testing

[0067] According to the national standard GB / T 40564-2021, the curing time, spiral flow length, viscosity, coefficient of thermal expansion, molding shrinkage rate and thermal conductivity of the epoxy resin molding compounds prepared in Examples 1-4 and Comparative Examples 1-7 were tested. The results are shown in Table 3.

[0068] Table 3

[0069]

[0070] Analysis of the table above shows that, compared with the epoxy resin molding compounds provided in Examples 1-7, Examples 1-4 can simultaneously achieve the following: spiral flow length > 50 inch at 175℃; viscosity < 15 Pa·s; coefficient of thermal expansion < 7 ppm at 40-80℃; coefficient of thermal expansion < 26 ppm at 200-240℃; molding shrinkage < 0.010%; and thermal conductivity > 3.5 W / (m·K).

Claims

1. An epoxy resin molding compound for C-Mold process, characterized in that, By weight, the product comprises at least the following raw materials: 1-4 parts of biphenyl-type epoxy resin, 1-2 parts of glycidyl amine epoxy resin, 1-2 parts of naphthalene-type epoxy resin, 3-6 parts of biphenyl-type phenolic resin, 85-88 parts of alumina, 1-3 parts of boron nitride, 0.2-1 parts of organosilicon, 0.5-3 parts of compound resin, and 0.5-3 parts of additives; the additives include at least a catalyst, a release agent, a coupling agent, and a colorant; the compound resin is phenylmethane maleic acid. The mixture comprises imide, bisphenol M cyanate, and polyurethane polyol resin; the mass ratio of phenylmethane maleimide, bisphenol M cyanate, and polyurethane polyol resin is (0.5-1):(0.5-1):(0.1-0.5); the organosilicon is an organosilicon elastomer and / or epoxy-modified silicone oil; the mass ratio of alumina and boron nitride is (85.5-87):(1-3); the compound resin is combined with biphenyl-type epoxy resin and glycidyl amine. The total mass ratio of epoxy resin and naphthalene ring epoxy resin is (1.8-2.5):(4-5); the biphenyl epoxy resin is a combination of crystalline biphenyl epoxy resin with an epoxy equivalent of 180-200 g / eq and biphenyl phenol type self-flame retardant epoxy resin with an epoxy equivalent of 260-300 g / eq; the mass ratio of the crystalline biphenyl epoxy resin, biphenyl phenol type self-flame retardant epoxy resin, glycidyl amine epoxy resin, and naphthalene ring epoxy resin is (1... .1-1.3):(1.1-1.3):(1.1-1.3):(1.1-1.3); The crystalline biphenyl type epoxy resin is model JX9000H, the biphenyl phenol type self-flame retardant epoxy resin is model BPNE3501LL, the tetrafunctional glycidylamine epoxy resin is model XB9721, the naphthalene ring type epoxy resin is model HP4700, and the biphenyl type phenolic resin is model SH-5075; The epoxy resin molding compound used in the C-Mold process has the following properties: a. Spiral flow length, 175℃ > 50 inches; b. Viscosity < 15 Pa·s; c. Thermal expansion coefficient at 40-80℃ < 7ppm; d. Coefficient of thermal expansion at 200-240℃ < 26ppm; e. Molding shrinkage rate < 0.010%; f. Thermal conductivity > 3.5 W / (m·K).

2. A method for preparing an epoxy resin molding compound for the C-Mold process according to claim 1, characterized in that, At least the following steps are included: (1) Add biphenyl phenolic resin, phenylmethane maleimide and release agent to a heated mixing tank and stir at 130-160℃ for 20-60 min to obtain mixture 1; (2) Add biphenyl epoxy resin, glycidyl amine epoxy resin, naphthalene ring epoxy resin, bisphenol M cyanate, polyurethane polyol resin, alumina, boron nitride, organosilicon, catalyst, coupling agent and colorant to a vertical stainless steel mixing tank and stir for 20-60 minutes to obtain mixture 2. (3) Mixing material 2 is mixed by a twin-screw extruder, cooled and crushed to obtain epoxy resin molding compound for C-Mold process.

3. An application of the epoxy resin molding compound for the C-Mold process according to claim 1, characterized in that, It is applied to the C-Mold process.

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