Epoxy plastic encapsulant, preparation method and application thereof

Abstract

The application relates to the field of epoxy plastic packaging materials, and discloses an epoxy plastic packaging material, a preparation method and application thereof. The epoxy plastic packaging material contains epoxy resin, phenolic resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier, colorant and release agent stabilizer. The release agent stabilizer includes main release agent stabilizer and auxiliary release agent stabilizer. The main release agent stabilizer is selected from one or more than two of tertiary amine compounds, diaryl secondary amine compounds and p-phenylenediamine compounds. The auxiliary release agent stabilizer is selected from one or more than two of mercaptan compounds, thioester compounds, dithio organic phosphate compounds and phosphite compounds. The epoxy plastic packaging material can realize continuous packaging, has excellent continuous packaging forming property, reduces the number of packaging defective products in the continuous packaging process, improves the efficiency of the continuous packaging, and has great industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of epoxy molding compounds, specifically to an epoxy molding compound, its preparation method, and its application. Background Technology

[0002] Epoxy molding compound is an encapsulation material based on epoxy resin, used for the encapsulation and protection of electronic devices. Epoxy resin is a bifunctional compound containing epoxy groups in its molecule, allowing it to react with active groups in other compounds to form a three-dimensional network structure. Therefore, it possesses excellent mechanical properties, good insulation properties, good chemical resistance, flexibility, and good adhesion.

[0003] As microelectronic devices continue to miniaturize and enhance their functionality, packaging structures require higher integration and performance. This drives packaging technology to continuously explore new packaging forms and levels, evolving from traditional two-dimensional packaging to three-dimensional packaging, stacked packaging, and other directions. In this process, epoxy molding compounds, as an important packaging material, are also facing increasingly demanding performance requirements. To adapt to the needs of new packaging structures, epoxy molding compounds need to possess higher heat resistance, thermal conductivity, and adhesion properties to achieve more compact and higher-performance packaging structures.

[0004] However, while ensuring the improved reliability of epoxy molding compounds, the operability of the encapsulation process also faces significant challenges. Epoxy molding compounds require high reliability and strong adhesion to the chip and frame, which means the bonding force between the epoxy molding compound and the mold surface must also increase, without compromising the continuous encapsulation molding performance. Simultaneously, to improve production efficiency, packaging manufacturers are gradually increasing the number of mold runs required for clearing and lubrication cycles, from the original 200 mold runs to 500 mold runs or even more, which also places higher demands on the continuous encapsulation molding performance of the molding compound.

[0005] The release mechanism of epoxy molding compound during continuous encapsulation relies primarily on the continuous precipitation of release agent within the molding compound, forming a separating wax layer between the mold and the molded body. During demolding, some wax adheres to the surface of the molded body and is carried away, while some wax remains on the mold cavity surface, repeating this process. A stable demolding state is characterized by a uniform amount of wax remaining in the mold cavity after each encapsulation cycle, neither increasing nor decreasing with each encapsulation cycle. However, the release agent remaining on the mold cavity surface, under prolonged high-temperature conditions of around 175°C, will gradually deteriorate, affecting the demolding effect and causing problems such as sticking, cracking, and missing corners. It will also affect the appearance of the molded body, resulting in uneven surface color, whitening, blackening, and wax marks.

[0006] Currently, methods to improve the continuous encapsulation moldability of epoxy molding compounds typically involve optimizing the type and dosage of release agents. However, this method only improves the continuous encapsulation moldability within a limited number of encapsulation cycles. For applications requiring a high number of encapsulation cycles, simply changing the composition and dosage of the release agent cannot solve the problem of deteriorated encapsulation performance caused by the oxidation and deterioration of the release agent. Therefore, improving the continuous encapsulation moldability of epoxy molding compounds is a pressing issue that needs to be addressed. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of poor encapsulation performance caused by mold release agent deterioration during continuous encapsulation using epoxy molding compounds in existing technologies, and to provide an epoxy molding compound, its preparation method, and its applications. The epoxy molding compound of this invention enables continuous encapsulation and possesses excellent continuous encapsulation molding properties, reducing the number of defective products during continuous encapsulation, improving the efficiency of continuous encapsulation, and possessing great potential for industrial applications.

[0008] To achieve the above objectives, the present invention provides an epoxy molding compound, which contains epoxy resin, phenolic resin, curing accelerator, inorganic filler, mold release agent, coupling agent, ion trapping agent, low-stress modifier, colorant, mold release agent stabilizer;

[0009] The release agent stabilizer includes a primary release agent stabilizer and an auxiliary release agent stabilizer;

[0010] The main release agent stabilizer is selected from one or more of tertiary amine compounds, diaryl secondary amine compounds, and p-phenylenediamine compounds.

[0011] Preferably, the auxiliary mold release agent stabilizer is selected from one or more of thiols, thioesters, dithioorganophosphates, and phosphites. Preferably, based on 100wt% of the total epoxy molding compound, the content of the epoxy resin is 6-19wt%, the content of the phenolic resin is 3-9wt%, the content of the curing accelerator is 0.1-0.5wt%, the content of the inorganic filler is 60-90wt%, the content of the mold release agent is 0.2-1.0wt%, the content of the coupling agent is 0.2-0.8wt%, the content of the ion scavenger is 0.05-1.0wt%, the content of the low-stress modifier is 0.1-2.0wt%, the content of the colorant is 0.05-1.0wt%, the content of the primary mold release agent stabilizer is 0.1%-3%, and the content of the auxiliary mold release agent stabilizer is 0.05-3%.

[0012] Preferably, the weight ratio of the primary release agent stabilizer to the auxiliary release agent stabilizer is 1 to 5:1.

[0013] Preferably, the main release agent stabilizer is selected from one or more of N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-diisooctyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, phenyl-α-naphthylamine, and phenyl-β-naphthylamine.

[0014] The auxiliary release agent stabilizer is preferably one or more selected from dioctadecyl thiodipropionate, phenyl diisodecyl phosphite, and trilauryl phosphite.

[0015] Preferably, the epoxy resin is selected from one or more of the following: o-cresol epoxy resin, biphenyl type epoxy resin, aralkyl type epoxy resin, ester ring type epoxy resin, heterocyclic type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene ring type epoxy resin, and multifunctional group type epoxy resin.

[0016] Preferably, the phenolic resin is selected from one or more of the following: linear phenolic resin and its derivatives, biphenyl-type phenolic resin, linear phenolic resin and its derivatives, monohydroxy or dihydroxynaphthol phenolic resin and its derivatives, condensates of p-xylene and phenol or naphthol, and copolymers of dicyclopentadiene and phenol.

[0017] Preferably, the curing accelerator is selected from one or two of triphenylphosphine and its derivatives, imidazole, 2-methylimidazolium, 2-ethyl-4-methylimidazolium, 1,8-diazabicycloundec-7-ene, and organic amine accelerators.

[0018] Preferably, the coupling agent is selected from one or more of γ-glycidyl ether trimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane.

[0019] Preferably, the inorganic filler is selected from any one or more of alumina, titanium dioxide, silicon nitride, aluminum nitride, and silicon dioxide;

[0020] Preferably, the silicon dioxide is crystalline silicon dioxide and / or molten silicon dioxide.

[0021] Preferably, the ion scavenger is selected from one or more of anion scavengers, cation scavengers, anion-cation composite ion scavengers, and hydrotalcite compounds;

[0022] Preferably, the low-stress modifier is selected from one or more of the following: silicone-modified epoxy resin, silicone resin, liquid-terminated carboxyl-terminated nitrile rubber, and triblock copolymers containing silicone components.

[0023] Preferably, the colorant is selected from one or more of carbon black, titanium dioxide, and zinc oxide.

[0024] Preferably, the release agent is selected from one or more of carnauba wax, polyethylene wax, oxidized polyethylene wax, Fischer-Tropsch wax, polypropylene wax, and fatty acid wax.

[0025] A second aspect of the present invention provides a method for preparing the aforementioned epoxy molding compound, the method comprising the following steps:

[0026] (1) The phenolic resin is heated and melted, then mixed with the main release agent stabilizer and the auxiliary release agent stabilizer, then the mixture is mixed with the release agent, then cooled and crushed and sieved;

[0027] (2) Mix the undersize material obtained in step (1), epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant, and then perform kneading.

[0028] Preferably, the heating and melting temperature is 110-170°C;

[0029] Preferably, the mixing temperature is 70-110℃.

[0030] A third aspect of the present invention provides the application of the epoxy molding compound in the packaging process of electronic devices.

[0031] The epoxy molding compound of this invention, by employing a combination of primary and secondary mold release stabilizers, effectively prevents the deterioration of the mold release agent in the epoxy molding compound, thereby further improving the moldability of the epoxy molding compound in continuous packaging processes and increasing the number of mold cycles in continuous packaging. Furthermore, by controlling the dosage of the primary and secondary mold release stabilizers, the molding performance of the epoxy molding compound can be further improved, resulting in superior continuous molding performance and better application in the continuous packaging process of electronic devices. The epoxy molding compound of this invention maintains a uniform and good appearance after 500 continuous packaging cycles, and is still less prone to problems such as sticking, cracking, corner chipping, and yellowing after multiple continuous packaging cycles, thus increasing the number of mold cleaning cycles. Moreover, after one mold cleaning cycle of continuous packaging, the epoxy molding compound of this invention has less contaminant on the mold cavity surface, making mold cleaning easier and extending the mold cleaning cycle. Detailed Implementation

[0032] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] In this invention, the epoxy molding compound contains epoxy resin, phenolic resin, curing accelerator, inorganic filler, release agent, coupling agent, ion trapping agent, low-stress modifier, colorant, release agent stabilizer.

[0035] In a specific embodiment, during continuous encapsulation using epoxy molding compound, the release agent, under the influence of heat and oxygen, generates free radicals ROO· at unstable structural sites. These active free radicals can initiate chain growth, chain transfer, and chain termination reactions, forming various impurity groups that affect the performance of the release agent itself. In this invention, by adding a primary release agent stabilizer, the function of the ROO· free radicals can be captured, forming relatively stable ROOH groups and preventing further oxidative deterioration of the release agent. Simultaneously, the added auxiliary release agent stabilizer can decompose large molecular hydrogen peroxide, transforming it into stable hydroxyl compounds, thereby further preventing oxidative deterioration of the release agent. Therefore, in this invention, the addition of a primary and auxiliary release agent stabilizer can delay the oxidative deterioration of the release agent, thus ensuring that the epoxy molding compound maintains excellent encapsulation properties during continuous encapsulation.

[0036] In this invention, the main release agent stabilizer is selected from one or more of tertiary amine compounds, diaryl secondary amine compounds, and p-phenylenediamine compounds, more preferably from one or more of N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-diisooctyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, phenyl-α-naphthylamine, and phenyl-β-naphthylamine.

[0037] In this invention, the auxiliary release agent stabilizer is selected from one or more of thiol compounds, thioester compounds, dithioorganophosphate compounds, and phosphite compounds, more preferably from one or more of dioctadecyl thiodipropionate, benzenediisodecyl phosphite, and trilauryl phosphite.

[0038] In a preferred embodiment, the weight ratio of the primary mold release agent stabilizer to the secondary mold release agent stabilizer is 1-5:1, with a most preferred ratio of 3:1. In this invention, by further limiting the amounts of the primary and secondary mold release agent stabilizers, the continuous encapsulation performance of the epoxy molding compound can be further improved, increasing the success rate and number of encapsulation cycles during continuous encapsulation, and thus improving the efficiency of continuous encapsulation.

[0039] In a preferred embodiment, the epoxy resin is selected from one or more of o-cresol epoxy resin, biphenyl type epoxy resin, aralkyl type epoxy resin, ester ring type epoxy resin, heterocyclic type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene ring type epoxy resin, and multifunctional group type epoxy resin.

[0040] In a preferred embodiment, the phenolic resin is selected from one or more of the following: linear phenolic resin and its derivatives, biphenyl-type phenolic resin, linear phenolic resin and its derivatives, monohydroxy or dihydroxynaphthol phenolic resin and its derivatives, condensates of p-xylene and phenol or naphthol, and copolymers of dicyclopentadiene and phenol.

[0041] In a preferred embodiment, the curing accelerator is selected from one or two of triphenylphosphine and its derivatives, imidazole, 2-methylimidazolium, 2-ethyl-4-methylimidazolium, 1,8-diazabicycloundec-7-ene, and organic amine accelerators.

[0042] In a preferred embodiment, the coupling agent is selected from one or more of γ-glycidyl ether trimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane.

[0043] In a preferred embodiment, the inorganic filler is selected from any one or more of alumina, titanium dioxide, silicon nitride, aluminum nitride, and silicon dioxide. More preferably, the silicon dioxide is crystalline silicon dioxide and / or fused silicon dioxide. Specifically, the crystalline silicon dioxide is crystalline silicon dioxide powder, which can be a commercially available product commonly used in the art, and the fused silicon dioxide can also be a commercially available product commonly used in the art.

[0044] In a preferred embodiment, the ion scavenger is selected from one or more of anion scavengers, cation scavengers, anion-cation composite ion scavengers, and hydrotalcite compounds.

[0045] In a preferred embodiment, the low-stress modifier is selected from one or more of the following: silicone-modified epoxy resin, silicone resin, liquid-terminated carboxyl-terminated nitrile rubber, and triblock copolymers containing silicone components.

[0046] In a preferred embodiment, the colorant is selected from one or more of carbon black, titanium dioxide, and zinc oxide.

[0047] In a preferred embodiment, the release agent is selected from one or more of carnauba wax, polyethylene wax, oxidized polyethylene wax, Fischer-Tropsch wax, polypropylene wax, and fatty acid wax.

[0048] In this invention, to improve the continuous encapsulation performance of the epoxy molding compound, based on a total epoxy molding compound of 100 wt%, the content of the epoxy resin is 6-19 wt%, the content of the phenolic resin is 3-9 wt%, the content of the curing accelerator is 0.1-0.5 wt%, the content of the inorganic filler is 60-90 wt%, the content of the release agent is 0.2-1.0 wt%, the content of the coupling agent is 0.2-0.8 wt%, the content of the ion scavenger is 0.05-1.0 wt%, the content of the low-stress modifier is 0.1-2.0 wt%, the content of the colorant is 0.05-1.0 wt%, the content of the main release agent stabilizer is 0.1%-3%, and the content of the auxiliary release agent stabilizer is 0.05-3%.

[0049] The present invention further provides a method for preparing the epoxy molding compound, the method comprising the following steps:

[0050] (1) The phenolic resin is heated and melted, then mixed with the main release agent stabilizer and the auxiliary release agent stabilizer, then the mixture is mixed with the release agent, then cooled and crushed and sieved;

[0051] (2) Mix the undersize material obtained in step (1), epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant, and then perform kneading.

[0052] In the method described in this invention, the main release agent stabilizer, the auxiliary release agent stabilizer and the phenolic resin are first mixed evenly, and then the resulting mixture is further mixed with the remaining components. By adopting a two-step mixing method, the release agent can be more accurately protected against oxidation, and the uniformity of the release agent in the epoxy molding compound is also improved, which has a significant effect on improving the continuous encapsulation molding properties of the epoxy molding compound.

[0053] In a preferred embodiment, in step (1), the heating and melting temperature is 110-170°C. Specifically, the heating and melting temperature can be 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, or 170°C.

[0054] In a specific embodiment, step (1) includes: heating the phenolic resin to 110-170℃ to melt it; then mixing the melted material with the main release agent stabilizer and the auxiliary release agent stabilizer; then mixing the mixture with the release agent; and finally cooling, pulverizing, and sieving. Specifically, the mixing time for mixing the melted material with the main release agent stabilizer and the auxiliary release agent stabilizer is 5-10 minutes; the mixing time for mixing the melted material with the main release agent stabilizer and the auxiliary release agent stabilizer is 30-90 minutes.

[0055] In a preferred embodiment, in step (2), the mixing temperature is 70-110°C. Specifically, the mixing temperature can be 70°C, 80°C, 90°C, 100°C, or 110°C.

[0056] The epoxy molding compound described in this invention has excellent continuous packaging performance in the continuous packaging process of electronic devices, which can meet the current requirements for continuous packaging of electronic devices. The product can still have a uniform and good appearance after 500 continuous packaging cycles. Furthermore, after multiple continuous packaging cycles, the packaged product is still not prone to sticking, tearing, and corner defects, which increases the number of mold clearing cycles and improves the efficiency of continuous packaging.

[0057] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0058] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0059] In the following examples and comparative examples, the o-cresol epoxy resin used was purchased from Jinan Shengquan Group Co., Ltd., brand name: SQCN700-3;

[0060] The linear phenolic resin was purchased from Jinan Shengquan Group Co., Ltd., and its grade was PF-8011.

[0061] 2-Ethyl-4-methylimidazolium, a curing accelerator, was purchased from Nanjing Lanbian Biochemical Technology Co., Ltd.

[0062] The coupling agent γ-glycidyl ether trimethoxysilane was purchased from Jiangsu Chenguang Company.

[0063] The low-stress modifier was silicone oil, purchased from Dow Corning, brand name SF-8241EG;

[0064] The ion-scavenging agent, hydrotalcite, was purchased from Kyowa Chemical Industry Co., Ltd., Japan, with the brand name DHT-4C.

[0065] The main release agent and stabilizer, phenyl-β-naphthylamine, was purchased from Tianjin Lab Additives Co., Ltd.

[0066] Dioctadecanyl thiodipropionate, an auxiliary release agent and stabilizer, was purchased from Jihong Chemical.

[0067] For details regarding the specific selection of raw materials and their dosages used in the preparation of epoxy molding compounds in the following examples and comparative examples, please refer to Table 1.

[0068] Example 1

[0069] (1) Heat the phenolic resin to 130℃ to melt it, then add the main release agent stabilizer and the auxiliary release agent stabilizer and stir for 8 minutes to mix. Then add the release agent to the mixture and stir for 60 minutes to mix evenly. Then cool the obtained material, then crush and sieve it.

[0070] (2) The sieve material obtained in step (1) is mixed with epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant. The resulting mixture is then added to a two-roll mill for mixing at a mixing temperature of 100°C.

[0071] Example 2

[0072] (1) Heat the phenolic resin to 130℃ to melt it, then add the main release agent stabilizer and the auxiliary release agent stabilizer and stir for 10 minutes to mix. Then add the release agent to the mixture and stir thoroughly for 90 minutes to mix evenly. Then cool the obtained material, then crush and sieve it.

[0073] (2) The sieve material obtained in step (1) is mixed with epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant. The resulting mixture is then added to a two-roll mill for mixing at a mixing temperature of 90°C.

[0074] Example 3

[0075] (1) Heat the phenolic resin to 140℃ to melt it, then add the main release agent stabilizer and the auxiliary release agent stabilizer and stir for 6 minutes to mix. Then add the release agent to the mixture and stir thoroughly for 40 minutes to mix evenly. Then cool the obtained material, then crush and sieve it.

[0076] (2) The sieve material obtained in step (1) is mixed with epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant. The resulting mixture is then added to a two-roll mill for mixing at a mixing temperature of 100°C.

[0077] Example 4

[0078] (1) Heat the phenolic resin to 150°C to melt it, then add the main release agent stabilizer and the auxiliary release agent stabilizer and stir for 5 minutes to mix. Then add the release agent to the mixture and stir for 40 minutes to mix evenly. Then cool the obtained material, then crush and sieve it.

[0079] (2) The sieve material obtained in step (1) is mixed with epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant. The resulting mixture is then added to a two-roll mill for mixing at a mixing temperature of 100°C.

[0080] Example 5

[0081] (1) Heat the phenolic resin to 130℃ to melt it, then add the main release agent stabilizer and the auxiliary release agent stabilizer and stir for 10 minutes to mix. Then add the release agent to the mixture and stir thoroughly for 90 minutes to mix evenly. Then cool the obtained material, then crush and sieve it.

[0082] (2) The undersize obtained in step (1) is mixed with epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant. The resulting mixture is then added to a two-roll mill for mixing at a mixing temperature of 80°C.

[0083] Example 6

[0084] The method described in Example 1 is implemented, except that the weight ratio of the primary release agent stabilizer to the secondary release agent stabilizer in the epoxy molding compound is 5.5:1, that is, the content of the primary release agent stabilizer is 0.253% and the content of the secondary release agent stabilizer is 0.046%.

[0085] Comparative Example 1

[0086] The method described in Example 1 is implemented, except that the epoxy molding compound does not contain a primary release agent stabilizer and an auxiliary release agent stabilizer, and the primary release agent stabilizer and the auxiliary release agent stabilizer are replaced with an equal weight of molten silica.

[0087] Comparative Example 2

[0088] Phenolic resin, main release agent stabilizer, auxiliary release agent stabilizer, epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant are mixed, and then the resulting mixture is added to a two-roll mill for mixing at a mixing temperature of 100℃.

[0089] The dosage and composition selection of phenolic resin, main release agent stabilizer, auxiliary release agent stabilizer, epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion scavenger, low stress modifier and colorant are the same as in Example 1.

[0090] Comparative Example 3

[0091] The method of Example 5 was implemented, except that the content of the main release agent stabilizer and the auxiliary release agent stabilizer was 4%, wherein the content of o-cresol epoxy resin was changed to 6.3% and the content of phenol linear phenolic resin was changed to 4.5%.

[0092] Comparative Example 4

[0093] The method described in Example 1 is implemented, except that the epoxy molding compound does not contain auxiliary release agent stabilizer, and the auxiliary release agent stabilizer is replaced with an equal weight of main release agent stabilizer.

[0094] Table 1

[0095]

[0096]

[0097] Test case

[0098] The properties of the materials prepared in Examples 1-6 and Comparative Examples 1-4 were tested using the following methods:

[0099] Gelation time: The test was conducted according to the method of national standard GB / T 40564-2021, and the test results are shown in Table 2.

[0100] Spiral flow length: The test was conducted according to the method of national standard GB / T 40564-2021, and the test results are shown in Table 2.

[0101] Continuous encapsulation test: The encapsulation press was Suzhou Shouken TO-220F, and the encapsulation process was a mold temperature of 175℃ and a mold closing pressure of 40-60 kg / cm². 2 The injection pressure is 50-70 kg / cm², and the curing time is 120 seconds. During the encapsulation process, observe for any issues such as sticking, cracking, missing corners, uneven coloring, whitening, blackening, or wax marks on the surface. If any problem occurs, the encapsulation cannot continue normally, and the normal continuous encapsulation cycle for that sample is the number of cycles encapsulated before the anomaly occurred. Simultaneously, observe the residual contaminants on the mold cavity surface after encapsulation; the color and amount of residual contaminants determine the condition of the dirty mold.

[0102] Table 2

[0103]

[0104]

[0105] As shown in Table 2, the addition of a primary release agent stabilizer and an auxiliary release agent stabilizer to the epoxy molding compound of this invention effectively improves the continuous encapsulation molding properties of the epoxy molding compound. Furthermore, by controlling the dosage of the primary and auxiliary release agent stabilizers, the epoxy molding compound can achieve a normal continuous encapsulation cycle of approximately 500 cycles or more. Simultaneously, after encapsulation, the residual contaminants in the mold cavity are minimal, the color is normal, mold cleaning is easy, and the mold cleaning cycle is extended. Moreover, by using a combination of the primary and auxiliary release agent stabilizers, the normal continuous encapsulation cycle can reach 600 cycles or more.

[0106] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An epoxy molding compound, characterized in that, The epoxy molding compound contains epoxy resin, phenolic resin, curing accelerator, inorganic filler, mold release agent, coupling agent, ion trapping agent, low-stress modifier, colorant, and mold release agent stabilizer; the mold release agent stabilizer includes a primary mold release agent stabilizer and an auxiliary mold release agent stabilizer. The primary mold release agent stabilizer is a diaryl secondary amine compound, and the secondary mold release agent stabilizer is a thioester compound; the weight ratio of the primary mold release agent stabilizer to the secondary mold release agent stabilizer is 1~5:

1. Based on a total epoxy molding compound of 100 wt%, the content of epoxy resin is 6-19 wt%, the content of phenolic resin is 3-9 wt%, the content of curing accelerator is 0.1-0.5 wt%, the content of inorganic filler is 60-90 wt%, the content of mold release agent is 0.2-1.0 wt%, the content of coupling agent is 0.2-0.8 wt%, the content of ion scavenger is 0.05-1.0 wt%, the content of low-stress modifier is 0.1-2.0 wt%, the content of colorant is 0.05-1.0 wt%, the content of main mold release agent stabilizer is 0.1%-3%, and the content of auxiliary mold release agent stabilizer is 0.05-3%. The preparation method of the epoxy molding compound includes the following steps: (1) The phenolic resin is heated and melted, then mixed with the main release agent stabilizer and the auxiliary release agent stabilizer, then the mixture is mixed with the release agent, then cooled and crushed and sieved; (2) Mix the undersize material obtained in step (1), epoxy resin, curing accelerator, inorganic filler, release agent, coupling agent, ion capture agent, low stress modifier and colorant, and then perform kneading.

2. The epoxy molding compound according to claim 1, characterized in that, The primary release agent stabilizer is selected from phenyl-α-naphthylamine and / or phenyl-β-naphthylamine; and / or The auxiliary release agent stabilizer is dioctadecyl thiodipropionate.

3. The epoxy molding compound according to claim 1 or 2, characterized in that, The epoxy resin is selected from one or more of the following: o-cresol epoxy resin, biphenyl type epoxy resin, aralkyl type epoxy resin, ester ring type epoxy resin, heterocyclic type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene ring type epoxy resin, and multifunctional group type epoxy resin.

4. The epoxy molding compound according to claim 1 or 2, characterized in that, The phenolic resin is selected from one or more of the following: linear phenolic resin and its derivatives, biphenyl-type phenolic resin, linear phenolic resin and its derivatives, monohydroxy or dihydroxynaphthol phenolic resin and its derivatives, condensates of p-xylene and phenol or naphthol, and copolymers of dicyclopentadiene and phenol; and / or The curing accelerator is selected from one or two of triphenylphosphine and its derivatives, imidazole, 2-methylimidazolium, 2-ethyl-4-methylimidazolium, 1,8-diazabicycloundec-7-ene, and organic amine accelerators.

5. The epoxy molding compound according to claim 1 or 2, characterized in that, The coupling agent is selected from one or more of γ-glycidyl ether trimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-aminopropyltrimethoxysilane; and / or The inorganic filler is selected from any one or more of alumina, titanium dioxide, silicon nitride, aluminum nitride, and silicon dioxide; and / or The silicon dioxide mentioned is crystalline silicon dioxide and / or molten silicon dioxide.

6. The epoxy molding compound according to claim 1 or 2, characterized in that, The ion scavenger is selected from one or more of anion scavengers, cationic scavengers, anion-cationic composite ion scavengers, and hydrotalcite compounds; and / or The low-stress modifier is selected from one or more of the following: silicone-modified epoxy resin, silicone resin, liquid carboxyl-terminated nitrile butadiene rubber, and triblock copolymers containing silicone components; and / or The colorant is selected from one or more of carbon black, titanium dioxide, and zinc oxide; and / or The release agent is selected from one or more of carnauba wax, polyethylene wax, oxidized polyethylene wax, Fischer-Tropsch wax, polypropylene wax, and fatty acid wax.

7. The epoxy molding compound according to claim 1, characterized in that, The heating and melting temperature is 110-170℃.

8. The epoxy molding compound according to claim 1, characterized in that, The mixing temperature is 70-110℃.

9. The application of the epoxy molding compound according to any one of claims 1-8 in the packaging process of electronic devices.

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