A DAF film slicing bottom film with adjustable modulus and a preparation method and application thereof

Abstract

The application provides a DAF film slicing bottom film with adjustable modulus and a preparation method and application thereof. The core layer of the DAF film slicing bottom film is a PO base material. The PO base material comprises the following components in parts by weight: a base resin 60-90 parts, a functional filler 5-30 parts, and a compatibilizer 1-5 parts. The base resin is composed of at least two of LLDPE, HDPE and POE. The functional filler comprises at least one of a rigid filler and an elastic filler. The PO base material comprises a low modulus PO base material, a medium modulus PO base material and a high modulus PO base material. Through the synergistic effect of molecular structure design, crystallinity regulation and functional filler modification, the wide range and precise regulation of the modulus of the PO base material are realized, so that the PO base material can match the corresponding modulus interval according to the requirements of different chip packaging processes, the problems of fixed modulus, poor adaptability and insufficient stability of the existing PO base material are solved, and the stability of the DAF film slicing process and the packaging yield are improved.

Description

Technical Field

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

[0002] In advanced semiconductor packaging, DAF (die bonding film) serves as the core adhesive material between the chip and the substrate / wafer. Its dicing substrate (also known as dicing tape substrate) plays a crucial role in supporting the chip during dicing, protecting it from mechanical damage, and assisting in chip removal. PO (polyolefin) has become the mainstream substrate for DAF dicing substrates due to its advantages such as low cost, good flexibility, and excellent interfacial compatibility with DAF films.

[0003] As semiconductor chips develop towards ultra-thin (≤50µm), high-density integration (3D stacking, Chiplet), and high power (SiC / GaN power devices), different chip packaging processes have placed differentiated and precise demands on the modulus of the PO substrate for the DAF film dicing substrate: ultra-thin chip dicing requires a low-modulus PO substrate to avoid chip breakage, 3D stacked chip dicing requires a medium-modulus PO substrate to balance support rigidity and peel stress, and high-power chip dicing requires a high-modulus PO substrate to improve deformation resistance and heat resistance.

[0004] Currently, the PO substrates for existing DAF film dicing bottom films are mostly prepared using a single formulation and process, resulting in a fixed modulus that cannot adapt to the differentiated requirements of different chip packaging processes. Developing separate PO substrates for different packaging processes would lead to a significant increase in production costs, reduced production efficiency, and difficulty in achieving precise modulus matching. Furthermore, existing methods for modulus control of PO substrates suffer from poor compatibility, easy filler segregation, and insufficient modulus stability, easily leading to defects such as chip warping during dicing, chip edge breakage during peeling, and easy deformation of the bottom film, affecting packaging yield and device reliability.

[0005] Therefore, developing a DAF film dicing substrate with precisely controllable PO substrate modulus, adaptable to different chip packaging process requirements, and stable performance, as well as its preparation method, has become an urgent technical problem to be solved in the field of semiconductor packaging materials.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a DAF film dicing substrate with adjustable modulus, its preparation method, and its application. Through the synergistic effect of molecular structure design, crystallinity control, and functional filler modification, a wide range of precise modulus control of the PO substrate of the DAF film dicing substrate is achieved. This allows the substrate to be matched with the corresponding modulus range according to the requirements of different chip packaging processes, solving the problems of fixed modulus, poor adaptability, and insufficient stability of existing PO substrates, and improving the stability of the DAF film dicing process and the packaging yield.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: A DAF membrane dicing substrate with adjustable modulus, wherein the core layer of the DAF membrane dicing substrate is a PO substrate; the PO substrate comprises the following components in parts by weight: 60-90 parts of base resin, 5-30 parts of functional filler, and 1-5 parts of compatibilizer. The base resin is a polyolefin blend system, which is composed of at least two of LLDPE, HDPE, and POE; the functional filler includes at least one of rigid filler and elastic filler. The PO substrate includes low-modulus PO substrate, medium-modulus PO substrate and high-modulus PO substrate.

[0009] Furthermore, the Young's modulus of the PO substrate can be adjusted within the range of 0.1-1.0 GPa.

[0010] Furthermore, the molecular weight of POE in the base resin ranges from 200,000 to 350,000.

[0011] Furthermore, the elastic filler is at least one of nitrile rubber, EVA elastomer, and POE elastomer; the molecular weight of the POE elastomer is in the range of 80,000-150,000.

[0012] Furthermore, the particle size of the elastic filler is 50-200 nm.

[0013] Furthermore, the rigid filler is at least one of calcium carbonate, talc, and kaolin.

[0014] Furthermore, the rigid filler has a particle size of 0.5-5µm.

[0015] Furthermore, the compatibilizer is at least one of maleic anhydride-grafted polyolefin and acrylic acid-grafted polyolefin.

[0016] Furthermore, the base resin includes LLDPE and POE, without the addition of HDPE, the mass ratio of LLDPE to POE is 5-7:3-5, the PO substrate is a low-modulus PO substrate, and the Young's modulus of the low-modulus PO substrate is 0.1-0.3 GPa.

[0017] Furthermore, the amount of functional filler added to the low-modulus PO substrate is 5-15 parts; the functional filler of the low-modulus PO substrate is an elastic filler.

[0018] Furthermore, the base resin includes LLDPE, HDPE and POE, the mass ratio of LLDPE, HDPE and POE is 4-6:2-3:2-3, the PO substrate is a medium modulus PO substrate, and the Young's modulus of the medium modulus PO substrate is 0.5-0.8 GPa, including 0.8 GPa.

[0019] Furthermore, the amount of functional filler added to the medium modulus PO substrate is 15-25 parts; the functional filler of the medium modulus PO substrate is a mixture of rigid filler and elastic filler, and the mass ratio of the rigid filler to the elastic filler is 2-3:1.

[0020] Furthermore, the base resin includes LLDPE and HDPE, without the addition of POE, the mass ratio of LLDPE to HDPE is 3-5:5-7, the PO substrate is a high modulus PO substrate, and the Young's modulus of the high modulus PO substrate is 0.8-1.0 GPa, excluding 0.8 GPa.

[0021] Furthermore, the amount of functional filler added to the high modulus PO substrate is 20-30 parts; the functional filler of the high modulus PO substrate is a rigid filler.

[0022] Furthermore, the PO substrate also includes auxiliary additives, which include: 0.5-2 parts of antioxidant and 0.5-2 parts of lubricant.

[0023] Furthermore, the DAF film dicing base film also includes an adhesive layer and a frosted layer, and adopts a three-layer co-extrusion structure, which consists of an adhesive layer, the core layer of the PO substrate, and a frosted layer from one side to the other.

[0024] Furthermore, the thickness of the adhesive coating layer is 10-40µm.

[0025] Furthermore, the adhesive layer is a mixture of ethylene-octene copolymer and ethylene-ethyl acrylate copolymer, and the mass ratio of ethylene-octene copolymer to ethylene-ethyl acrylate copolymer in the adhesive layer is 6-9:1.

[0026] Furthermore, the core layer has a thickness of 50-100µm.

[0027] Furthermore, the thickness of the frosted layer is 10-40µm.

[0028] Furthermore, the material of the frosted layer is a mixture of ethylene-octene copolymer and opening functional masterbatch, and the mass ratio of ethylene-octene copolymer to opening functional masterbatch in the frosted layer is 25-50:1.

[0029] Furthermore, the total thickness of the DAF membrane dicing substrate is 70-180 μm, preferably 80-150 μm.

[0030] The preparation method of the above-mentioned adjustable modulus DAF film dicing substrate includes the following steps: Step 1: Mix the components of the PO substrate evenly according to the proportion to obtain a mixture; Step 2: Grind the mixture and then degas it under vacuum to obtain a uniform PO substrate mixture; and prepare the adhesive layer mixture and the frosted layer mixture separately. Step 3: The adhesive layer mixture, the PO substrate mixture, and the frosted layer mixture are melt-co-extruded. Step 4: Cool and shape the co-extruded film to obtain the DAF film substrate with PO base material.

[0031] Furthermore, the mixing process in step 1 is as follows: mix for 15-30 minutes at a temperature of 80-100℃ and a rotation speed of 300-500 r / min.

[0032] Furthermore, in step 2, the dispersion of the functional filler in the ground material is ≤1µm, and the vacuum degassing time is 10-20min.

[0033] Furthermore, in step 3, the extrusion temperature of the PO substrate mixture in the melt co-extrusion process is controlled at 160-220℃, and the extrusion temperature of the adhesive layer mixture and the sanding layer mixture is controlled at 150-210℃.

[0034] Furthermore, in step 3, the blow-up ratio during the melt co-extrusion process is controlled at 1.5-3.0, and the traction speed is controlled at 10-50 m / min.

[0035] Furthermore, during the cooling and shaping process in step 4, the cooling rate is controlled at 5-30℃ / s.

[0036] Furthermore, when preparing low-modulus PO substrate, the cooling rate is controlled at 5-10℃ / s during the cooling and shaping process in step 4.

[0037] Furthermore, when preparing medium-modulus PO substrate, the cooling rate is controlled at 10-20℃ / s during the cooling and shaping process in step 4.

[0038] Furthermore, when preparing the high-modulus PO substrate, the cooling rate is controlled at 20-30℃ / s during the cooling and shaping process in step 4.

[0039] The above-mentioned adjustable modulus DAF film dicing substrate and the adjustable modulus DAF film dicing substrate obtained by the above preparation method are applied in 3D chip stacking, rigid chip packaging, consumer electronics packaging, ultra-thin chip packaging, and flexible electronic packaging processes.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention relates to a DAF film substrate with adjustable modulus and its preparation method. Through the synergistic effect of molecular structure design (basic resin blending ratio control), crystallinity control (cooling rate) and functional filler modification (rigid filler / elastic filler selection and addition amount control), the modulus of PO substrate can be precisely controlled within the range of 0.1-1.0 GPa. The corresponding modulus range can be matched according to the needs of different chip packaging processes, solving the problem of fixed modulus and poor adaptability of existing PO substrates.

[0041] 2. The adjustable modulus DAF dicing substrate of this invention improves the interfacial compatibility between the base resin and functional fillers by adding a compatibilizer, avoiding functional filler segregation and ensuring the uniformity and stability of the modulus of the PO substrate. At the same time, the three-layer co-extrusion structure, combined with the coating layer and the frosting layer, not only increases the interfacial adhesion between the dicing substrate and the acrylic adhesive, but also reduces blade wear during dicing, reduces the generation of cutting debris, and further improves the stability of the dicing process and the encapsulation yield.

[0042] 3. The method for preparing the dicing substrate of the adjustable modulus DAF film of the present invention is simple in process, highly operable, requires no additional special equipment, and can achieve large-scale production; by using the same set of production processes and only adjusting the formula ratio and process parameters, dicing substrates adapted to different chip packaging processes (ultra-thin chips, 3D stacked chips, high-power chips) can be prepared, which greatly reduces production costs and improves production efficiency.

[0043] 4. The PO substrate of the adjustable modulus DAF film dicing base film of this invention has stable modulus and strong adaptability, which can effectively avoid defects such as chip warping during dicing, chip edge breakage during peeling, and easy deformation of the base film, thereby improving the dicing performance and packaging reliability of the DAF film and providing material support for the development of advanced semiconductor packaging technology. Detailed Implementation

[0044] 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.

[0045] A DAF membrane dicing substrate with adjustable modulus, wherein the core layer of the DAF membrane dicing substrate is a PO substrate; the PO substrate comprises the following components in parts by weight: 60-90 parts of base resin, 5-30 parts of functional filler, and 1-5 parts of compatibilizer. The base resin is a polyolefin blend system, which is composed of at least two of linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), and ethylene-octene copolymer (POE) blended in a certain proportion; the functional filler includes at least one of rigid filler and elastic filler. The PO substrate includes low-modulus PO substrate, medium-modulus PO substrate and high-modulus PO substrate.

[0046] This invention achieves control over the molecular structure of the PO substrate by adjusting the blending ratio of the polyolefin blend system, thereby controlling the modulus of the PO substrate. The functional filler is used to assist in controlling the modulus of the PO substrate, and rigid fillers and / or elastic fillers are selected according to the modulus control requirements. The Young's modulus of the PO substrate can be controlled within the range of 0.1-1.0 GPa, adapting to the requirements of different chip packaging processes.

[0047] In some embodiments, the molecular weight of the ethylene-octene copolymer (POE) in the base resin ranges from 200,000 to 350,000, and a commonly used brand is Dow Chemical (model ENGAGE). TM 8402), ExxonMobil (model Exact) TM 8201), etc.

[0048] In some embodiments, the elastic filler is at least one of nitrile rubber, EVA elastomer, and POE elastomer. The elastic filler is used to reduce the modulus of the PO substrate and improve its flexibility.

[0049] In some embodiments, the particle size of the elastic filler is 50-200nm, including but not limited to 50nm, 75nm, 100nm, 125nm, 150nm, 175nm, and 200nm.

[0050] In some embodiments, the molecular weight of the POE elastomer ranges from 80,000 to 150,000, and common brands include Mitsui Chemicals (model DF740) and LG Chem (model LC170).

[0051] In some embodiments, the rigid filler is at least one selected from calcium carbonate, talc, and kaolin. The rigid filler is used to improve the rigidity and deformation resistance of the PO substrate.

[0052] In some embodiments, the rigid filler has a particle size of 0.5-5µm, including but not limited to 0.5μm, 1μm, 2μm, 3μm, 4μm, and 5μm.

[0053] In some embodiments, the base resin comprises LLDPE and POE, without the addition of HDPE. The mass ratio of LLDPE to POE is 5-7:3-5 (including but not limited to 5:5, 5.5:4.5, 6:4, 6.5:3.5, and 7:3). The PO substrate is a low-modulus PO substrate with a Young's modulus of 0.1-0.3 GPa. The POE has many branches and low crystallinity, which weakens the molecular chain forces, improves flexibility, and thus reduces the modulus.

[0054] In some embodiments, the amount of functional filler added to the low-modulus PO substrate is 5-15 parts.

[0055] Furthermore, the functional filler of the low-modulus PO substrate is an elastic filler, used to reduce the modulus of the PO substrate and improve its flexibility.

[0056] In some embodiments, the base resin includes LLDPE, HDPE, and POE, with the mass ratio of LLDPE, HDPE, and POE being 4-6:2-3:2-3 (including but not limited to 4:3:3, 5:2.5:2.5, and 6:2:2). The PO substrate is a medium-modulus PO substrate with a Young's modulus of 0.5-0.8 GPa, inclusive. The HDPE (high crystallinity, high rigidity) and the POE (low rigidity) work synergistically to balance molecular chain forces, achieving a moderate modulus.

[0057] In some embodiments, the amount of functional filler added to the medium modulus PO substrate is 15-25 parts.

[0058] Furthermore, the functional filler of the medium modulus PO substrate is a combination of rigid filler and elastic filler, with the mass ratio of the rigid filler to the elastic filler being 2-3:1, including but not limited to 2:1, 2.2:1, 2.5:1, 2.8:1, and 3:1. The combination of rigid filler and elastic filler, with the elastic filler offsetting the rigidity, can balance the rigidity and flexibility of the membrane material, as well as balance the support and cushioning properties.

[0059] In some embodiments, the base resin includes LLDPE and HDPE, without the addition of POE. The mass ratio of LLDPE to HDPE is 3-5:5-7 (including but not limited to 3:7, 3.5:6.5, 4:6, 4.5:5.5, and 5:5). The PO substrate is a high-modulus PO substrate with a Young's modulus of 0.8-1.0 GPa, excluding 0.8 GPa. The HDPE has high crystallinity and regular molecular chains, which enhances molecular chain forces and improves modulus and rigidity.

[0060] In some embodiments, the amount of functional filler added to the high modulus PO substrate is 20-30 parts.

[0061] Furthermore, the functional filler of the high-modulus PO substrate is a rigid filler, used to improve the rigidity and deformation resistance of the PO substrate.

[0062] In some embodiments, the compatibilizer is at least one of maleic anhydride-grafted polyolefin (MAH-g-PO) and acrylic acid-grafted polyolefin (AA-g-PO), used to improve the interfacial compatibility between the base resin and the functional filler, avoid segregation of the functional filler, and ensure the uniformity and stability of the modulus of the PO substrate.

[0063] Optionally, the maleic anhydride-grafted polyolefin (MAH-g-PO) is at least one of maleic anhydride-grafted ethylene-octene copolymer (MAH-g-POE) and maleic anhydride-grafted polyethylene (MAH-g-PE). Alternatively, the maleic anhydride-grafted polyolefin (MAH-g-PO) can be a commercially available general-purpose MAH-g-PO.

[0064] In some embodiments, the PO substrate further includes auxiliary additives, which include: 0.5-2 parts of antioxidant and 0.5-2 parts of lubricant.

[0065] In some embodiments, the antioxidant is at least one of 2,6-di-tert-butyl-p-cresol (BHT), 2,6-di-tert-butyl-4-ethylphenol (BHEB), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), and isooctyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1135).

[0066] In some embodiments, the lubricant is at least one of butyl stearate, stearic acid, and zinc stearate.

[0067] In some embodiments, the DAF film dicing base film also includes an adhesive layer and a frosted layer, and adopts a three-layer co-extrusion structure, which consists of an adhesive layer, the core layer of the PO substrate, and a frosted layer from one side to the other.

[0068] In some embodiments, the thickness of the adhesive coating is 10-40µm (including but not limited to 10µm, 20µm, 30µm, and 40µm).

[0069] In some implementations, the core layer thickness is 50-100µm (including but not limited to 50µm, 60µm, 70µm, 80µm, 90µm, and 100µm).

[0070] In some embodiments, the thickness of the abrasive layer is 10-40µm (including but not limited to 10µm, 20µm, 30µm, and 40µm). The abrasive layer of the present invention serves to reduce blade wear during dicing, reduce the generation of cutting debris, improve its own surface smoothness, prevent film adhesion, help ensure the stability of the dicing process, and indirectly improve the packaging yield.

[0071] In some embodiments, the total thickness of the DAF membrane scriber substrate is 70-180 μm, including but not limited to 70 μm, 80 μm, 100 μm, 120 μm, 150 μm, and 180 μm, preferably 80-150 μm.

[0072] In some embodiments, the adhesive layer is a mixture of ethylene-octene copolymer (POE, molecular weight 200,000-350,000) and ethylene-ethyl acrylate copolymer, wherein the mass ratio of ethylene-octene copolymer to ethylene-ethyl acrylate copolymer in the adhesive layer is 6-9:1, including but not limited to 6:1, 7:1, 8:1, and 9:1. The adhesive layer of this invention is made of ethylene-octene copolymer and ethylene-ethyl acrylate copolymer, which has excellent compatibility with acrylic adhesive, enabling a tight bond between the dicing film and the acrylic adhesive.

[0073] In some embodiments, the abrasive layer is a mixture of ethylene-octene copolymer (POE, molecular weight 200,000-350,000) and a cutting masterbatch, wherein the mass ratio of ethylene-octene copolymer to cutting masterbatch in the abrasive layer is 25-50:1 (including but not limited to 25:1, 30:1, 35:1, 40:1, 45:1, 50:1). The abrasive layer can reduce blade wear during dicing and reduce the generation of cutting debris.

[0074] Furthermore, the opening-type functional masterbatch is a functional masterbatch made by using polyolefin as a carrier, adding opening agents (silica, talc) and slip agents, and then melt-mixing and granulating it.

[0075] Furthermore, the carrier is at least one of HDPE, LLDPE, and POE (molecular weight of 80,000-150,000), which is compatible with the PO substrate.

[0076] Furthermore, the opening agent is at least one of silica and talc.

[0077] Furthermore, the slip agent is a specialized additive adapted to polyolefin systems.

[0078] Furthermore, the slip agent is at least one of stearamide, oleamide, and erucamide.

[0079] The preparation method of the above-mentioned adjustable modulus DAF film dicing substrate includes the following steps: Step 1: Mix the components of the PO substrate (base resin, functional filler, compatibilizer, antioxidant and lubricant) in a high-speed mixer according to the proportion to obtain a mixture. Step 2: After grinding the mixture in a grinder, it is fed into a vacuum degassing machine to remove air bubbles from the material, resulting in a uniform PO substrate mixture; and then the adhesive layer mixture and the frosted layer mixture are prepared separately. Step 3: Feed the adhesive layer mixture, PO substrate mixture, and frosted layer mixture into the three extruders of the three-layer co-extrusion blown film machine for melt co-extrusion; Step 4: The co-extruded film is fed into a cooling roller for cooling and shaping to obtain the DAF film dicing base film of PO substrate.

[0080] In some embodiments, the mixing process in step 1 is as follows: mixing for 15-30 minutes (including but not limited to 15 minutes, 20 minutes, 25 minutes, and 30 minutes) at a temperature of 80-100℃ (including but not limited to 80℃, 85℃, 90℃, 95℃, and 100℃) and a rotation speed of 300-500 r / min (including but not limited to 300 r / min, 350 r / min, 400 r / min, 450 r / min, and 500 r / min).

[0081] In some embodiments, the functional filler dispersion of the material after grinding in step 2 is ≤1µm, and the degassing time in the vacuum degassing machine is 10-20min (including but not limited to 10min, 12min, 15min, 18min, 20min).

[0082] In some embodiments, the extrusion temperature of the PO substrate mixture in the melt co-extrusion process in step 3 is controlled at 160-220℃ (including but not limited to 160℃, 180℃, 200℃, 220℃), and the extrusion temperature of the adhesive layer mixture and the frosted layer mixture is controlled at 150-210℃ (including but not limited to 150℃, 180℃, 200℃, 210℃).

[0083] In some embodiments, the blow-up ratio in the melt co-extrusion process in step 3 is controlled at 1.5-3.0 (including but not limited to 1.5, 2, 2.5, 3), and the traction speed is controlled at 10-50 m / min (including but not limited to 10 m / min, 20 m / min, 30 m / min, 40 m / min, 50 m / min).

[0084] In some implementations, the cooling rate is controlled at 5-30℃ / s during the cooling and shaping process in step 4.

[0085] Furthermore, during step 4, the crystallinity of the PO substrate is controlled by adjusting the cooling rate. The adjustment method is as follows: When preparing low-modulus PO substrate, the cooling rate is controlled at 5-10℃ / s. The slower cooling rate allows sufficient time for the molecular chains to arrange themselves in a regular manner, resulting in lower crystallinity (≤40%) and weaker molecular chain forces, thus causing the PO substrate to have a lower modulus. When preparing medium-modulus PO substrate, the cooling rate is controlled at 10-20℃ / s. The regularity of the molecular chain arrangement is moderate, and the crystallinity is controlled at 40%-50%, resulting in a medium modulus of the PO substrate. When preparing high-modulus PO substrate, the cooling rate is controlled at 20-30℃ / s. The molecular chains solidify rapidly, resulting in a high degree of regularity, increased crystallinity (≥50%), and stronger molecular chain forces, thus causing the PO substrate to have a higher modulus.

[0086] The above-mentioned adjustable modulus DAF film dicing substrate and the adjustable modulus DAF film dicing substrate obtained by the above preparation method are used in different chip packaging processes such as ultra-thin chip dicing, 3D stacked chip dicing, and high-power chip dicing. The DAF film dicing substrate is coated with an acrylic adhesive to obtain PO acrylic tape, which is then cut into the required size and then attached to the DAF film to obtain the die-cutting bonding film (DDAF).

[0087] In some embodiments, the acrylic adhesive is at least one of UV acrylic adhesive and non-UV acrylic adhesive.

[0088] In some embodiments, the acrylic adhesive is applied by at least one of slot coating and mesh coating.

[0089] In some embodiments, the acrylic adhesive coating thickness is 10-20µm, including but not limited to 10µm, 12µm, 15µm, 18µm, and 20µm.

[0090] Furthermore, the thickness of the DAF film is 10-30µm, including but not limited to 10µm, 15µm, 20µm, 25µm, and 30µm.

[0091] Examples 1-3 and Comparative Examples 1-3 A method for preparing a DAF membrane scribing substrate includes the following steps: Step 1: Add the base resin, functional filler, compatibilizer, antioxidant and lubricant to a high-speed mixer according to the formulation components in Table 1, and mix for 20 minutes at 90℃ and 400r / min until the mixture is uniform. Step 2: Grind the mixture in a grinder until the functional filler dispersion is ≤1µm, then degas under vacuum for 15min to obtain the PO substrate mixture; and prepare the coating layer mixture and the frosted layer mixture according to the formulation components in Table 1 respectively. Step 3: Feed the adhesive layer mixture, PO substrate mixture and frosted layer mixture into the three extruders of the three-layer co-extrusion blown film machine for melt co-extrusion. The extrusion temperature of the PO substrate is 180℃, the extrusion temperature of the adhesive layer and the frosted layer is 170℃, the blow-up ratio is 2.0, and the traction speed is 20m / min. Step 4: The co-extruded film is fed into a cooling roller for cooling and shaping. The specific cooling rate is shown in Table 1.

[0092] The formulation components and cooling rates of the DAF membrane scribing substrate in the preparation methods of Examples 1-3 and Comparative Examples 1-3 of this invention are shown in Table 1 (the unit of each component in the table is kg, such as LLDPE 4.2, which is LLDPE 4.2 kg).

[0093] Table 1. Formulation components and cooling rates of the DAF membrane scribing substrate preparation methods in Examples 1-3 and Comparative Examples 1-3.

[0094] Test case The DAF membranes prepared in Examples 1-3 and Comparative Examples 1-3 of this invention were subjected to performance tests, and the test results are shown in Table 2.

[0095] The Young's modulus of the DAF film scribing base film was tested according to GB / T 1040.1-2025 "Determination of tensile properties of plastics - Part 1: General rules"; the coefficient of thermal expansion of the DAF film scribing base film was obtained by static thermomechanical analysis (TMA), and the test standard was ISO 11359-2:2021 "Plastics - Thermomechanical analysis (TMA)"; the glass transition temperature of the DAF film scribing base film was obtained by dynamic thermomechanical analysis (DMA), and the test standard was GB / T 33061.11-2022 "Determination of dynamic mechanical properties of plastics - Part 11: Glass transition temperature".

[0096] Table 2. Performance test results of DAF membranes prepared in Examples 1-3 and Comparative Examples 1-3.

[0097] Compared to Example 1, Comparative Example 1 used LLDPE as the base resin, and all other formulation components and preparation process parameters were identical. Because POE was not added, Comparative Example 1 could not effectively weaken the molecular chain forces, resulting in a higher modulus. Furthermore, the effective molecular chain forces led to better heat resistance, i.e., a higher glass transition temperature. The rigid structure also restricted the thermal movement of the resin molecular chains, reducing thermal expansion. However, the lack of the elastic component POE resulted in higher rigidity in Comparative Example 1, causing slight breakage of the ultrathin chip during dicing and making it prone to edge chipping. This led to decreased dicing stability and a significant drop in packaging yield, making it unsuitable for the requirements of ultrathin chip packaging.

[0098] The formulation and preparation method of Comparative Example 2 are basically the same as those of Example 2, the only difference being that the functional filler used is a single rigid filler, calcium carbonate. The combination of elastic and rigid fillers can balance the rigidity and flexibility of the membrane material. Therefore, with the same amount of functional filler, Comparative Example 2 lacks elastic filler to offset rigidity, resulting in a significant increase in the proportion of rigid components. This leads to a decrease in the deformation capacity of the PO molecular chains under stress, and the modulus exceeds the medium modulus range. As an amorphous elastomer, the elastic filler's amorphous molecular chains act as "hindrance factors," interspersed between PO molecular chains, hindering their close packing and orderly arrangement, thus disrupting the regularity of the PO molecular chains. In contrast, the rigid filler, with its regular crystalline structure, can act as a "nucleus" for the PO molecular chains, guiding their orderly arrangement and improving the regularity of the molecular chains. Comparative Example 2, with only rigid filler, has a higher degree of molecular chain regularity, resulting in stronger intermolecular forces, a higher glass transition temperature, and a lower coefficient of thermal expansion. Meanwhile, the lack of a combination of rigid and elastic fillers, with only a single rigid filler added, resulted in excessively high rigidity and insufficient flexibility of the membrane material. This made it impossible to balance support and cushioning, leading to uneven stress during the dicing process, which could easily cause warping and breakage, reduced dicing stability, and a significant drop in encapsulation yield.

[0099] The formulation and preparation method of Comparative Example 3 are basically the same as those of Example 3, the only difference being that the cooling rate was adjusted to 8℃ / s. Due to the excessively slow cooling rate, the PO molecular chains in Comparative Example 3 did not have enough time to crosslink and crystallize, resulting in low crystallinity and insufficient modulus. Furthermore, the low degree of crosslinking failed to improve the heat resistance and deformation resistance of the film material, leading to a low glass transition temperature and a high coefficient of thermal expansion. Therefore, the base film was prone to deformation during high-temperature dicing, resulting in unstable chip support, decreased dicing stability, and a significant drop in packaging yield, making it unsuitable for high-temperature packaging processes.

[0100] Therefore, by adjusting the blending ratio of LLDPE, HDPE and POE in the base resin, controlling the crystallinity of different cooling rates, and the synergistic effect of rigid filler / elastic filler selection, the modulus of PO substrate can be controlled in different ranges, solving the problem of fixed modulus and poor adaptability of existing PO substrates.

[0101] This invention can prepare dicing films for high-modulus PO substrates, medium-modulus PO substrates, and low-modulus PO substrates through the synergistic effects of molecular structure design (basic resin blending ratio control), crystallinity control (cooling rate), and filler modification (rigid / elastic filler selection and addition amount control) according to the packaging scenario requirements. By applying dicing films of PO substrates with different moduli on DAF films, dicing films of different moduli can be obtained to obtain dicing chip bonding films (DDAF) suitable for various packaging scenarios such as 3D chip stacking, rigid chip (such as high-power chip) packaging, consumer electronics packaging, ultra-thin chip packaging, and flexible electronic packaging.

[0102] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A DAF film dicing dielectric film with tunable modulus, characterized in that, The core layer of the DAF membrane scribing base film is a PO substrate; the PO substrate comprises the following components by weight: 60-90 parts of base resin, 5-30 parts of functional filler, and 1-5 parts of compatibilizer; The base resin is a polyolefin blend system, which is composed of at least two of LLDPE, HDPE, and POE; the functional filler includes at least one of rigid filler and elastic filler. The PO substrate includes low-modulus PO substrate, medium-modulus PO substrate and high-modulus PO substrate.

2. The controllable modulus DAF membrane dicing dielectric film according to claim 1, wherein, It should include at least one of the following technical features: (1) The Young's modulus of the PO substrate can be adjusted in the range of 0.1-1.0 GPa; (2) The molecular weight range of POE in the base resin is 200,000-350,000; (3) The elastic filler is at least one of nitrile rubber, EVA elastomer, and POE elastomer; the molecular weight range of the POE elastomer is 80,000-150,000; (4) The particle size of the elastic filler is 50-200 nm; (5) The rigid filler is at least one of calcium carbonate, talc, and kaolin; (6) The particle size of the rigid filler is 0.5-5µm; (7) The compatibilizer is at least one of maleic anhydride-grafted polyolefin and acrylic acid-grafted polyolefin.

3. The controllable modulus DAF membrane dicing dielectric film according to claim 2, wherein, Includes any of the following technical features: (1) The base resin includes LLDPE and POE, without HDPE, the mass ratio of LLDPE to POE is 5-7:3-5, the PO substrate is a low modulus PO substrate, and the Young's modulus of the low modulus PO substrate is 0.1-0.3 GPa. (2) The base resin includes LLDPE, HDPE and POE, the mass ratio of LLDPE, HDPE and POE is 4-6:2-3:2-3, the PO substrate is a medium modulus PO substrate, the Young's modulus of the medium modulus PO substrate is 0.5-0.8 GPa, including 0.8 GPa; (3) The base resin includes LLDPE and HDPE, without POE, the mass ratio of LLDPE to HDPE is 3-5:5-7, the PO substrate is a high modulus PO substrate, the Young's modulus of the high modulus PO substrate is 0.8-1.0 GPa, excluding 0.8 GPa.

4. The controllable modulus DAF membrane dicing dielectric film according to claim 3, wherein, Includes any of the following technical features: (1) The amount of the functional filler added to the low modulus PO substrate is 5-15 parts; the functional filler of the low modulus PO substrate is an elastic filler; (2) The amount of the functional filler added to the medium modulus PO substrate is 15-25 parts; the functional filler of the medium modulus PO substrate is a combination of rigid filler and elastic filler, and the mass ratio of the rigid filler to the elastic filler is 2-3:1; (3) The amount of the functional filler added to the high modulus PO substrate is 20-30 parts; the functional filler of the high modulus PO substrate is a rigid filler.

5. The controllable modulus DAF membrane dicing dielectric film of claim 1, wherein, The PO substrate also includes auxiliary additives, which include: 0.5-2 parts of antioxidant and 0.5-2 parts of lubricant.

6. The modulus-controllable DAF film dicing sheet of any one of claims 1-5, wherein, The DAF film dicing base film also includes an adhesive layer and a frosted layer, and adopts a three-layer co-extrusion structure, which consists of an adhesive layer, the core layer of the PO substrate, and a frosted layer from one side to the other.

7. The controllable modulus DAF membrane dicing dielectric film according to claim 6, wherein, It should include at least one of the following technical features: (1) The thickness of the adhesive coating is 10-40µm; (2) The material of the coating layer is a mixture of ethylene-octene copolymer and ethylene-ethyl acrylate copolymer, and the mass ratio of ethylene-octene copolymer to ethylene-ethyl acrylate copolymer in the coating layer is 6-9:1; (3) The core layer has a thickness of 50-100µm; (4) The thickness of the frosted layer is 10-40µm; (5) The material of the frosted layer is a mixture of ethylene-octene copolymer and open-cell functional masterbatch, and the mass ratio of ethylene-octene copolymer to open-cell functional masterbatch in the frosted layer is 25-50:1; (6) The total thickness of the DAF membrane substrate is 70-180μm, preferably 80-150µm.

8. The method for preparing the DAF film substrate with adjustable modulus as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: Mix the components of the PO substrate evenly according to the proportion to obtain a mixture; Step 2: Grind the mixture and then degas it under vacuum to obtain a uniform PO substrate mixture; and prepare the adhesive layer mixture and the frosted layer mixture separately. Step 3: The adhesive layer mixture, the PO substrate mixture, and the frosted layer mixture are melt-co-extruded. Step 4: Cool and shape the co-extruded film to obtain the DAF film substrate with PO base material.

9. The method for preparing the DAF film substrate with adjustable modulus according to claim 8, characterized in that, It should include at least one of the following technical features: (1) The mixing process in step 1 is as follows: mix for 15-30 minutes at a temperature of 80-100℃ and a rotation speed of 300-500r / min; (2) The dispersion of the functional filler in the material after grinding in step 2 is ≤1µm, and the vacuum degassing time is 10-20min; (3) In step 3, the extrusion temperature of the PO substrate mixture in the melt co-extrusion process is controlled at 160-220℃, and the extrusion temperature of the adhesive layer mixture and the sanding layer mixture is controlled at 150-210℃; (4) In step 3, the blow-up ratio of the melt co-extrusion process is controlled at 1.5-3.0, and the traction speed is controlled at 10-50 m / min; (5) During the cooling and shaping process in step 4, the cooling rate is controlled at 5-30℃ / s; (6) When preparing low modulus PO substrate, the cooling rate is controlled at 5-10℃ / s during the cooling and shaping process in step 4; (7) When preparing medium modulus PO substrate, the cooling rate is controlled at 10-20℃ / s during the cooling and shaping process in step 4; (8) When preparing high modulus PO substrate, the cooling rate is controlled at 20-30℃ / s during the cooling and shaping process in step 4.

10. The application of the adjustable modulus DAF membrane scribing substrate as described in any one of claims 1 to 7, and the adjustable modulus DAF membrane scribing substrate obtained by the preparation method described in claim 8 or 9, characterized in that, Applications in 3D chip stacking, rigid chip packaging, consumer electronics packaging, ultra-thin chip packaging, and flexible electronic packaging processes.

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