Modulus-controllable chip bonding film, preparation method and application thereof

Abstract

The application provides a chip bonding film with adjustable modulus and a preparation method and application thereof, the film comprises the following components in parts by weight: 30-70 parts of epoxy resin, 30-70 parts of acrylic resin, 10-20 parts of heat-conducting filler, 2-5 parts of curing agent, 0.5-2 parts of coupling agent and 0.1-1 part of anti-aging agent; the chip bonding film with adjustable modulus comprises a high modulus type DAF film, a medium modulus type DAF film and a low modulus type DAF film. The modulus of the DAF film is adjusted by adjusting the mixing ratio of the epoxy resin and the acrylic resin, the modulus of the DAF film can be efficiently and accurately adjusted, meanwhile, the core performances such as bonding strength, heat conductivity, flexibility and stress buffering capacity are good, and the film is suitable for the requirements of various different semiconductor packaging scenes such as 3D chip stacking, rigid chip packaging, consumer electronic packaging, ultra-thin chip packaging and flexible electronic packaging.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and more specifically, to a chip bonding film (DAF) with adjustable modulus, its preparation method, and its application. Background Technology

[0002] With the rapid development of 5G, artificial intelligence, and new energy vehicle industries, semiconductor devices are evolving towards high-density integration, ultra-thinness, and heterogeneous packaging. Advanced technologies such as 3D stacking and chiplets place stringent demands on the performance of chip bonding materials. Traditional fluid die bonders, due to defects such as adhesive overflow, uneven bond layer thickness (BLT), and poor thermal stress matching, are no longer suitable for ultra-thin chip (≤100μm) packaging processes and high-temperature service scenarios, resulting in limited packaging yield and device reliability, becoming a key bottleneck restricting the implementation of advanced packaging technologies.

[0003] Chip bonding film (DAF) replaces traditional fluid die bond adhesive in thin film form and can be used to achieve high-performance, high-reliability connection between chip and substrate or lead frame. It plays a key role in chip-to-substrate / wafer bonding, packaging process support and device reliability assurance.

[0004] With the rapid development of semiconductor technology towards ultra-thin, high-density integration and 3D stacked packaging, the precise adaptability of the modulus performance of chip bonding film (DAF), as a core packaging material, has become a key factor affecting packaging yield and device reliability. Different packaging scenarios have significantly different requirements for DAF film modulus: for example, ultra-thin chip packaging below 25μm requires low-modulus (1MPa~500MPa) materials to buffer interfacial thermal stress and avoid chip cracking; general consumer electronics packaging requires medium-modulus (500MPa~1GPa) products to balance adhesive strength and flexibility; and 3D IC stacked packaging requires high-modulus (1GPa~5GPa) materials to provide stable mechanical support and ensure the accuracy of multi-layer chip stacking.

[0005] In existing technologies, the modulus of DAF membranes is mainly controlled by adding inorganic fillers and optimizing the curing agent ratio. However, these methods still have many drawbacks: for example, while a high filler content can increase the modulus, it can lead to decreased membrane flexibility and insufficient adhesion toughness, and uneven filler dispersion can easily cause performance fluctuations; a low filler content is difficult to meet the high modulus requirements and may also weaken thermal conductivity. On the other hand, the curing agent dosage has a narrow range of influence on the modulus and can easily change the curing rate and long-term reliability of the DAF membrane.

[0006] Therefore, there is an urgent need for a DAF membrane preparation technology that does not rely on a large amount of inorganic fillers (more than 30%) or complex additives, can achieve precise control of a wide range of moduli through simple and efficient formulation adjustments, and at the same time take into account core properties such as adhesive strength, thermal stability, and flexibility.

[0007] In view of this, the present invention is hereby proposed. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by providing a chip bonding film with adjustable modulus, its preparation method, and its application. By adjusting the mixing ratio of epoxy resin and acrylic resin, the modulus of the DAF film can be controlled efficiently and precisely, while also taking into account the core properties such as good bonding strength, thermal conductivity, flexibility, and stress buffering capacity, thus adapting to the needs of different semiconductor packaging scenarios.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A chip bonding film with adjustable modulus comprises the following components in parts by weight: 30-70 parts epoxy resin, 30-70 parts acrylic resin, 10-20 parts thermally conductive filler, 2-5 parts curing agent, 0.5-2 parts coupling agent, and 0.1-1 parts anti-aging agent; the chip bonding film with adjustable modulus includes high-modulus DAF film, medium-modulus DAF film, and low-modulus DAF film.

[0010] Furthermore, the mass ratio of the epoxy resin to the acrylic resin is 6:4 to 7:3, and the chip bonding film is a high-modulus DAF film with a modulus greater than 1 GPa.

[0011] Furthermore, the mass ratio of the epoxy resin to the acrylic resin is 5.99:4.01~4.01:5.99, and the chip bonding film is a medium-modulus DAF film with a modulus of 500MPa~1GPa.

[0012] Furthermore, the mass ratio of the epoxy resin to the acrylic resin is 3:7 to 4:6, and the chip bonding film is a low-modulus DAF film with a modulus of less than 500 MPa.

[0013] Furthermore, the epoxy resin is at least one of bisphenol A type epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin.

[0014] Furthermore, the acrylic resin is at least one of hydroxyl acrylic resin, epoxy acrylate, polyurethane acrylate, and acrylate copolymer.

[0015] Furthermore, the thermally conductive filler is at least one of alumina, magnesium oxide, aluminum nitride, and hexagonal boron nitride.

[0016] Further, the curing agent is at least one selected from 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenylimidazole, dicyandiamide, and methylnadic anhydride.

[0017] Further, the coupling agent is at least one selected from γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropyltriethoxysilane.

[0018] Further, the anti-aging agent is at least one selected from 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-butylhydroquinone (DTBHQ), 4-hydroxymethyl-2,6-di-tert-butylphenol, trinonylphenyl phosphite (TNPP), tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0019] Furthermore, the bisphenol A type epoxy resin is at least one of E-51, E-44, and E-20.

[0020] Furthermore, the phenolic epoxy resin is at least one of F-51, NPPN-638, and EPN-1138.

[0021] Furthermore, the alicyclic epoxy resin is at least one of CY-179 and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate.

[0022] Further, the acrylate copolymer is at least one of butyl acrylate-methyl methacrylate copolymer, ethyl acetate-butyl acrylate copolymer, and methyl methacrylate-acrylic acid-butyl acrylate terpolymer.

[0023] The method for preparing the above-mentioned adjustable modulus chip bonding film includes the following steps: Step S1: Weigh the epoxy resin, acrylic resin, and coupling agent according to the proportion, and mix them evenly to obtain the resin matrix; Step S2: Add thermally conductive filler, curing agent, anti-aging agent and solvent to the resin matrix, mix evenly and then degas under vacuum; Step S3: Apply the degassed adhesive onto the protective film; Step S4: Heat the coated film to cure it, and then cool it to obtain the DAF film.

[0024] Further, in step S1, the epoxy resin, acrylic resin, and coupling agent are stirred at 60~80℃ and 500~800r / min for 30~60min.

[0025] Further, in step S2, thermally conductive filler, curing agent, anti-aging agent and solvent are added to the resin matrix, and stirring is continued for 60~90min to form a glue solution. Then, under vacuum degree ≥-0.09MPa and temperature 50~60℃, degassing is carried out for 30~45min to remove bubbles and impurities from the glue solution.

[0026] Furthermore, the solvent used in step S2 is at least one of ethyl acetate, toluene, acetone, and cyclohexane.

[0027] Furthermore, step S3 involves slit coating.

[0028] Furthermore, in step S3, the thickness of the adhesive coating is 10~30μm.

[0029] Furthermore, the thickness of the protective film in step S3 is 25~50μm.

[0030] Furthermore, the protective film mentioned in step S3 is at least one of PET, PE, and PP protective films.

[0031] Furthermore, in step S4, the film material is cured according to a stepped heating curve. The stepped heating process is as follows: the first stage is to heat up to 80~90℃ and hold for 30~40 minutes; the second stage is to heat up to 120~130℃ and hold for 60~70 minutes; and the third stage is to heat up to 150~160℃ and hold for 30~40 minutes.

[0032] The above-mentioned adjustable modulus chip bonding film and the above-mentioned preparation method are applied in 3D chip stacking, rigid chip packaging, consumer electronics packaging, ultra-thin chip packaging, and flexible electronic packaging, by attaching at least one layer of acrylic tape to the die-cut DAF film.

[0033] Furthermore, the acrylic tape is at least one of non-UV dicing film and UV dicing film.

[0034] Furthermore, the acrylic tape comprises an acrylic adhesive layer with a thickness of 10-30 μm and a base film with a thickness of 80-150 μm, wherein the base film is at least one of PO film, PET film, and PP film.

[0035] Furthermore, the die-cutting method of the DAF film is as follows: after peeling off the protective film, the DAF film is die-cut to the required size, and the excess edges after die-cutting are removed as waste.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention relates to a modulus-adjustable chip bonding film and its preparation method. By adjusting the ratio of epoxy resin to acrylic resin, the modulus of the DAF film can be flexibly controlled, while taking into account the core properties such as good bonding strength, thermal conductivity, flexibility, and stress buffering capacity. It does not require the addition of a large amount of filler, thus avoiding the imbalance of DAF film performance.

[0037] 2. The present invention relates to a chip bonding film with adjustable modulus, its preparation method, and its application. It can quickly adjust the ratio of epoxy resin to acrylic resin according to the packaging scenario requirements to prepare high, medium, and low modulus DAF films, which are suitable for various packaging scenarios such as ultra-thin chips, 3D stacking, and flexible electronics, and meet the basic requirements of semiconductor packaging.

[0038] 3. In the epoxy resin and acrylic resin formulation system of the chip adhesive film with adjustable modulus of the present invention, the epoxy resin molecular chain contains highly active epoxy groups (-COC-), which form a three-dimensional cross-linked network after curing. Its main molecular chain contains a rigid benzene ring structure with high cross-linking density, which endows the DAF film with excellent mechanical strength, high temperature resistance and structural stability. It is the core component for improving the film modulus. The epoxy resin can ensure the bonding strength and high temperature resistance. The acrylic resin molecular chain contains flexible alkyl chains (-CH2-CH2-) and functional groups such as hydroxyl (-OH) and carboxyl (-COOH). The flexible alkyl chains can reduce the intermolecular forces and improve the flexibility and stress buffering capacity of the film. The hydroxyl and carboxyl groups of the acrylic resin can undergo cross-linking reaction with the epoxy groups of the epoxy resin to achieve chemical bonding between the two resins. Its molecular chain flexibility is the key to reducing the film modulus. The acrylic resin can ensure flexibility and stress buffering capacity. Detailed Implementation

[0039] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0040] A chip bonding film with adjustable modulus comprises the following components in parts by weight: 30-70 parts epoxy resin, 30-70 parts acrylic resin, 10-20 parts thermally conductive filler, 2-5 parts curing agent, 0.5-2 parts coupling agent, and 0.1-1 parts anti-aging agent; the chip bonding film with adjustable modulus includes high-modulus DAF film, medium-modulus DAF film, and low-modulus DAF film.

[0041] In the present invention, the total weight parts of epoxy resin and acrylic resin in the modulus-adjustable chip bonding film are greater than 60 parts. The modulus of the chip bonding film can be adjusted by adjusting the mass ratio of the epoxy resin and the acrylic resin.

[0042] Preferably, the mass ratio of the epoxy resin to the acrylic resin is 6:4 to 7:3 (including but not limited to 6:4, 6.1:3.9, 6.2:3.8, 6.3:3.7, 6.4:3.6, 6.5:3.5, 6.6:3.4, 6.7:3.3, 6.8:3.2, 6.9:3.1, and 7:3), and the chip bonding film is a high-modulus DAF film with a modulus greater than 1 GPa, suitable for 3D chip stacking and rigid chip packaging.

[0043] Preferably, the mass ratio of the epoxy resin to the acrylic resin is 5.99:4.01 to 4.01:5.99 (including but not limited to 5.99:4.01, 5.9:4.1, 5.8:4.2, 5.7:4.3, 5.6:4.4, 5.5:4.5, 5.4:4.6, 5.3:4.7, 5.2:4.8, 5.1:4.9, 5.0:5.0, ...). (4.9:5.1, 4.8:5.2, 4.7:5.3, 4.6:5.4, 4.5:5.5, 4.4:5.6, 4.3:5.7, 4.2:5.8, 4.1:5.9, 4.01:5.99), the chip bonding film is a medium-modulus DAF film, the modulus of which is 500MPa~1GPa, suitable for general consumer electronics packaging.

[0044] Preferably, the mass ratio of the epoxy resin to the acrylic resin is 3:7 to 4:6 (including but not limited to 3:7, 3.1:6.9, 3.2:6.8, 3.3:6.7, 3.4:6.6, 3.5:6.5, 3.6:6.4, 3.7:6.3, 3.8:6.2, 3.9:6.1, and 4:6), and the chip bonding film is a low-modulus DAF film with a modulus of less than 500 MPa, suitable for ultra-thin chip and flexible substrate packaging.

[0045] Preferably, the epoxy resin is at least one of bisphenol A type epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin.

[0046] Preferably, the bisphenol A type epoxy resin is at least one of E-51 (EPON 828), E-44, and E-20; the phenolic epoxy resin is at least one of F-51, NPPN-638, and EPN-1138; and the alicyclic epoxy resin is at least one of CY-179 and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate (ERL-4221).

[0047] Preferably, the acrylic resin is at least one of hydroxyl acrylic resin, epoxy acrylate, polyurethane acrylate, butyl acrylate-methyl methacrylate copolymer, ethyl acetate-butyl acrylate copolymer, and methyl methacrylate-acrylic acid-butyl acrylate terpolymer.

[0048] The mechanism by which this invention regulates modulus changes by adjusting the mass ratio of two resins mainly stems from the structural differences between epoxy resin and acrylic resin. The epoxy resin used is bisphenol A type epoxy resin, phenolic type epoxy resin, or alicyclic epoxy resin. Its molecular chain contains highly reactive epoxy groups (-COC-), forming a three-dimensional cross-linked network after curing. Its main molecular chain contains a rigid benzene ring structure with high cross-linking density, giving the DAF film excellent mechanical strength, high-temperature resistance, and structural stability, making it the core component for improving the film modulus. The acrylic resin used is hydroxyl acrylic resin, epoxy acrylate, polyurethane acrylate, or acrylate copolymer. Its molecular chain contains flexible alkyl chains (-CH2-CH2-) and functional groups such as hydroxyl (-OH) and carboxyl (-COOH). The flexible alkyl chains can reduce the intermolecular forces, improving the film's flexibility and stress buffering capacity. The hydroxyl and carboxyl groups of the acrylic resin can undergo cross-linking reactions with the epoxy groups of the epoxy resin, achieving chemical bonding between the two resins. The flexibility of its molecular chain is key to reducing the film modulus.

[0049] Preferably, the thermally conductive filler is at least one of alumina, magnesium oxide, aluminum nitride, and hexagonal boron nitride.

[0050] Preferably, the curing agent is at least one selected from 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenylimidazole, dicyandiamide, and methylnadic anhydride.

[0051] Preferably, the coupling agent is at least one selected from γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropyltriethoxysilane.

[0052] Preferably, the anti-aging agent is at least one of 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-butylhydroquinone (DTBHQ), 4-hydroxymethyl-2,6-di-tert-butylphenol, trinonylphenyl phosphite (TNPP), tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168), and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0053] A method for preparing a chip bonding film with adjustable modulus includes the following steps: Step S1: Weigh out epoxy resin, acrylic resin, and 0.5-2 parts of coupling agent according to the proportion, and mix them evenly to obtain the resin matrix; Step S2: Add 10-20 parts of thermally conductive filler, 2-5 parts of curing agent, 0.1-1 parts of anti-aging agent, and 40-60 parts of solvent to the resin matrix, mix evenly, and then degas under vacuum. Step S3: Apply the degassed adhesive onto the protective film; Step S4: Place the coated film material into an oven, heat it to cure, and then cool it to obtain a DAF film.

[0054] Preferably, in step S1, epoxy resin, acrylic resin, and coupling agent are added to a high-speed mixer and stirred for 30 to 60 minutes (including but not limited to 60°C, 65°C, 70°C, 75°C, 80°C) at a speed of 500 to 800 r / min (including but not limited to 500 r / min, 600 r / min, 700 r / min, 800 r / min) at a speed of 500 to 800 r / min (including but not limited to 500 r / min, 600 r / min, 700 r / min, 800 r / min).

[0055] Preferably, in step S2, thermally conductive filler, curing agent, anti-aging agent, and solvent are added to the resin matrix, and stirring is continued for 60-90 minutes (including but not limited to 60 minutes, 70 minutes, 80 minutes, and 90 minutes) to form a glue solution. Subsequently, degassing is performed for 30-45 minutes (including but not limited to 30 minutes, 35 minutes, 40 minutes, and 45 minutes) under vacuum conditions ≥-0.09 MPa and temperature conditions 50-60°C (including but not limited to 50°C, 52°C, 55°C, 58°C, and 60°C) to remove bubbles and impurities from the glue solution.

[0056] Preferably, the solvent used in step S2 is at least one of ethyl acetate (EA), toluene, acetone, and cyclohexane. Preferably, the coating method in step S3 is slot coating.

[0057] Preferably, the thickness of the adhesive coating in step S3 is 10~30μm, including but not limited to 10μm, 15μm, 20μm, 25μm, and 30μm.

[0058] Preferably, the thickness of the protective film in step S3 is 25~50μm, including but not limited to 25μm, 30μm, 35μm, 40μm, 45μm, and 50μm.

[0059] Preferably, the protective film in step S3 is at least one of PET, PE, and PP protective films.

[0060] Preferably, in step S4, the film material is cured according to a stepped heating curve. The stepped heating process is as follows: the first stage is to heat to 80~90℃ (including but not limited to 80℃, 82℃, 84℃, 86℃, 88℃, 90℃) and hold for 30~40min (including but not limited to 30min, 32min, 34min, 36min, 38min, 40min); the second stage is to heat to 120~130℃ (including but not limited to 120℃, 122℃, 124℃, 126℃, ...). The first stage involves holding the material at 128℃ or 130℃ for 60-70 minutes (including but not limited to 60 min, 62 min, 64 min, 66 min, 68 min, and 70 min), followed by a third stage of heating to 150-160℃ (including but not limited to 150℃, 152℃, 154℃, 156℃, 158℃, and 160℃) and holding for 30-40 minutes (including but not limited to 30 min, 32 min, 34 min, 36 min, 38 min, and 40 min). This invention employs a stepped heating curve to cure the film material, allowing for stepwise activation of the curing agent and orderly advancement of the resin crosslinking reaction. This avoids the problems of incomplete crosslinking, residual bubbles, and internal stress accumulation caused by curing at a single temperature. Simultaneously, it promotes the formation of a uniform and stable crosslinked structure between the epoxy resin and acrylic resin, laying the foundation for precise modulus control.

[0061] The above-mentioned adjustable modulus chip bonding film and its preparation method are applied in 3D chip stacking, rigid chip packaging, consumer electronics packaging, ultra-thin chip packaging, and flexible electronic packaging by attaching at least one layer of acrylic tape to the die-cut DAF film.

[0062] Preferably, the acrylic tape is at least one of non-UV dicing film and UV dicing film.

[0063] Preferably, the acrylic tape comprises an acrylic adhesive layer with a thickness of 10-30 μm (including but not limited to 10 μm, 15 μm, 20 μm, 25 μm, 30 μm) and a base film with a thickness of 80-150 μm (including but not limited to 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm), wherein the base film is at least one of PO film (polyolefin film), PET film, and PP film.

[0064] Preferably, the die-cutting method of the DAF film is as follows: after peeling off the protective film, the DAF film is die-cut to the required size, and the excess edges after die-cutting are discharged as waste.

[0065] Examples 1-3 and Comparative Examples 1-2 A method for preparing and applying a DAF membrane includes the following steps: (1) Weigh epoxy resin, acrylic resin and 1 part of coupling agent according to the formula ratio in Table 1, add them to a high-speed mixer, and stir for 40 minutes at 60℃ and 600r / min to obtain a uniform resin matrix. (2) Add 20 parts of thermally conductive filler, 3 parts of curing agent, 0.5 parts of anti-aging agent and 50 parts of solvent to the resin matrix, continue stirring for 70 min, and then degas for 40 min under vacuum degree ≥ -0.09 MPa and temperature 60℃ to remove bubbles and impurities; (3) The degassed adhesive is coated onto the protective film PET (40μm thick) using a slot coater, with a coating thickness of 20μm; (4) Place the coated film in an oven and cure it according to the stepped temperature curve: 80℃ / 30min→120℃ / 60min→150℃ / 30min to obtain DAF film; (5) After cooling to room temperature, peel off the protective film from the DAF film and die-cut it into standard sizes of 8 inches or 12 inches. Remove any excess material from the die-cut edges. (6) Apply a 100μm UV-type PO tape to the die-cut DAF film to obtain the finished product.

[0066] The DAF membrane formulations in the DAF membrane preparation methods of Examples 1-3 and Comparative Examples 1-2 of this invention are shown in Table 1 (the unit of each component in the table is g, such as epoxy resin 30, which is epoxy resin 30g).

[0067] Table 1. DAF membrane formulations of Examples 1-3 and Comparative Examples 1-3

[0068] Comparative Example 3 The difference between this comparative example and Example 1 is that step (4) involves placing the coated film in an oven and heating it to 150°C for 120 minutes to cure it, thereby obtaining the DAF film. The remaining steps are the same as in Example 1.

[0069] Test case The DAF membranes prepared by the formulations and methods of Examples 1-3 and Comparative Examples 1-3 were subjected to the following performance tests, and the test results are shown in Table 2.

[0070] I. The test method for Young's modulus of DAF film is based on GB / T 1040-2006 "Determination of tensile properties of plastics - Part 1: General rules"; II. The test method for the shear bond strength of DAF film is based on GB / T 7754-1987 "Test method for shear strength of pressure sensitive adhesive tape (adhesive side and back side)"; 3. The coefficient of thermal expansion of the DAF film was obtained by static thermomechanical analysis (TMA), and the test standard was ISO11359 "Thermomechanical analysis of plastics (TMA)". IV. The glass transition temperature of the DAF film was obtained by dynamic thermomechanical analyzer (DMA), and the test standard was GB / T 33061.11-2022 "Determination of dynamic mechanical properties of plastics - Part 11: Glass transition temperature".

[0071] Table 2 Performance test results of DAF membranes prepared in Examples 1-3 and Comparative Examples 1-3

[0072] As can be seen from the data in Table 2, the modulus of the DAF film can be controlled within different ranges by adjusting the ratio of epoxy resin to acrylic resin. Therefore, in the formulation system of this invention, epoxy resin ensures bonding strength and high-temperature resistance, while acrylic resin enhances flexibility and stress buffering capacity. Under the synergistic effect of the two, the shear bonding strength of the DAF film after curing is ≥3MPa (25℃), and the glass transition temperature (Tg) is ≥120℃, meeting the basic requirements of semiconductor packaging. The glass transition temperature can reflect the flexibility and stress buffering capacity of the DAF film. The lower the glass transition temperature, the better its flexibility and stress buffering capacity; the higher the glass transition temperature, the harder and more brittle the DAF film, and the worse its flexibility and stress buffering capacity.

[0073] This invention can quickly, efficiently, and accurately adjust the ratio of epoxy resin to acrylic resin according to the needs of the packaging scenario to prepare high-modulus DAF film, medium-modulus DAF film, and low-modulus DAF film, which are suitable for various packaging scenarios such as 3D chip stacking, rigid chip packaging, consumer electronics packaging, ultra-thin chip packaging, and flexible electronic packaging.

Claims

1. A chip bonding film with adjustable modulus, characterized in that, The components include the following parts by weight: 30-70 parts epoxy resin, 30-70 parts acrylic resin, 10-20 parts thermally conductive filler, 2-5 parts curing agent, 0.5-2 parts coupling agent, and 0.1-1 parts anti-aging agent; the adjustable modulus chip bonding film includes high modulus DAF film, medium modulus DAF film and low modulus DAF film.

2. The chip bonding film with adjustable modulus according to claim 1, characterized in that, Includes any of the following technical features: (1) The mass ratio of the epoxy resin to the acrylic resin is 6:4 to 7:3, and the chip bonding film is a high modulus DAF film with a modulus greater than 1 GPa. (2) The mass ratio of the epoxy resin to the acrylic resin is 5.99:4.01~4.01:5.99, and the chip bonding film is a medium modulus DAF film with a modulus of 500MPa~1GPa. (3) The mass ratio of the epoxy resin to the acrylic resin is 3:7 to 4:6, and the chip bonding film is a low-modulus DAF film with a modulus of less than 500 MPa.

3. The chip bonding film with adjustable modulus according to claim 1 or 2, characterized in that, It should include at least one of the following technical features: (1) The epoxy resin is at least one of bisphenol A type epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin; (2) The acrylic resin is at least one of hydroxyl acrylic resin, epoxy acrylate, polyurethane acrylate, and acrylate copolymer; (3) The thermally conductive filler is at least one of alumina, magnesium oxide, aluminum nitride, and hexagonal boron nitride; (4) The curing agent is at least one of 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenylimidazole, dicyandiamide, and methylnadic anhydride; (5) The coupling agent is at least one of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane; (6) The anti-aging agent is at least one of 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-butylhydroquinone, 4-hydroxymethyl-2,6-di-tert-butylphenol, trinonylphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

4. The chip bonding film with adjustable modulus according to claim 3, characterized in that, It should include at least one of the following technical features: (1) The bisphenol A type epoxy resin is at least one of E-51, E-44, and E-20; (2) The phenolic epoxy resin is at least one of F-51, NPPN-638, and EPN-1138; (3) The alicyclic epoxy resin is at least one of CY-179 and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate; (4) The acrylate copolymer is at least one of butyl acrylate-methyl methacrylate copolymer, ethyl acetate-butyl acrylate copolymer, and methyl methacrylate-acrylic acid-butyl acrylate terpolymer.

5. The method for preparing a chip bonding film with adjustable modulus as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step S1: Weigh the epoxy resin, acrylic resin, and coupling agent according to the proportion, and mix them evenly to obtain the resin matrix; Step S2: Add thermally conductive filler, curing agent, anti-aging agent and solvent to the resin matrix, mix evenly and then degas under vacuum; Step S3: Apply the degassed adhesive onto the protective film; Step S4: Heat the coated film to cure it, and then cool it to obtain the DAF film.

6. The method for preparing a chip bonding film with adjustable modulus according to claim 5, characterized in that, It should include at least one of the following technical features: (1) In step S1, the epoxy resin, acrylic resin and coupling agent are stirred at 60~80℃ and 500~800r / min for 30~60min; (2) In step S2, thermally conductive filler, curing agent, anti-aging agent and solvent are added to the resin matrix and stirred for 60~90min to form a glue solution. Then, under vacuum degree ≥-0.09MPa and temperature 50~60℃, degassing is carried out for 30~45min to remove bubbles and impurities from the glue solution. (3) The solvent used in step S2 is at least one of ethyl acetate, toluene, acetone, and cyclohexane; (4) The coating method in step S3 is slot coating; (5) The thickness of the adhesive coating in step S3 is 10~30μm; (6) The thickness of the protective film mentioned in step S3 is 25~50μm; (7) The protective film mentioned in step S3 is at least one of PET, PE and PP protective films.

7. The method for preparing a chip bonding film with adjustable modulus according to claim 5, characterized in that, In step S4, the film material is cured according to the stepped heating curve. The stepped heating process is as follows: the first stage is to heat up to 80~90℃ and hold for 30~40min; the second stage is to heat up to 120~130℃ and hold for 60min~70min; and the third stage is to heat up to 150~160℃ and hold for 30min~40min.

8. The application of the adjustable modulus chip bonding film as described in any one of claims 1 to 4 and the preparation method as described in any one of claims 5 to 7 in 3D chip stacking, rigid chip packaging, consumer electronics packaging, ultrathin chip packaging, and flexible electronic packaging, characterized in that: Apply at least one layer of acrylic tape to the die-cut DAF film.

9. The application according to claim 8, characterized in that, The acrylic tape is at least one of non-UV dicing film and UV dicing film.

10. The application according to claim 8 or 9, characterized in that, It should include at least one of the following technical features: (1) The acrylic tape comprises an acrylic adhesive layer with a thickness of 10~30μm and a base film with a thickness of 80~150μm, wherein the base film is at least one of PO film, PET film and PP film; (2) The die-cutting method of the DAF film is as follows: after peeling off the protective film, the DAF film is die-cut to the required size, and the excess edge after die-cutting is discharged as waste.

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