Chip packaging adhesive film and preparation method thereof

Abstract

The invention relates to a chip packaging adhesive film and a preparation method thereof. The chip packaging adhesive film comprises epoxy resin, a curing agent and an auxiliary agent, the epoxy resin comprises 72-86% of alicyclic epoxy resin, 3-8% of triglycidyl isocyanurate, 5-10% of organosilicon modified epoxy resin and 6-10% of an epoxy resin flexibilizer, and the total fraction of the epoxy resin is 100%; the curing agent comprises 80-87% of a styrene-maleic anhydride polymer, 3-5% of a special anhydride curing agent and 10-15% of hexahydrophthalic anhydride, and the total percentage of the curing agent is 100%; the auxiliaries comprise an accelerant, a defoaming agent, a wetting agent, a flatting agent and a solvent. The materials are heated, stirred, dissolved and mixed to prepare a glue solution, and then the glue solution is processed into a continuous and compact glue film through a coating machine. The adhesive film is cured at the temperature of 90-110 DEG C / (1-2 h) + (150-180 DEG C) / (3-5 h), the prepared epoxy resin adhesive film has high light transmittance, high temperature resistance, high cohesiveness and excellent film-forming property, the chip is protected, sealed and prevented from deforming and warping, meanwhile, the service life of the chip is prolonged, and the comprehensive performance of the chip is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular to a chip packaging adhesive film and a preparation method thereof. Background Art

[0002] Emerging packaging processes place increasingly stringent requirements on packaging materials.

[0003] Due to the inherent defects of the material, epoxy resin encapsulation films are prone to deformation, warping, and large shrinkage, which affects the yield and processability of chip packaging. In order to compensate for this defect, a high amount of powder filler must be added to the encapsulation film to minimize the linear expansion coefficient of the material. However, this approach will sacrifice many of the unique properties of epoxy resin, such as adhesion, mechanical properties, insulation, and light transmittance, and the results are usually not very good. This approach is especially not applicable in some application scenarios that have high requirements for the light transmittance of the film.

[0004] Therefore, while taking into account the high transmittance of the product, we strive to solve the warpage compensation problem of the packaged product. This work requires balancing the glass transition temperature and linear expansion coefficient, high transmittance and yellowing resistance, product processability and film-forming properties, etc. The difficulty is quite high. This has largely restricted the breakthrough of advanced packaging technology and is an industry problem that needs to be solved urgently.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of the deficiencies in the prior art, the embodiments of the present invention disclose a chip encapsulation film and a preparation method thereof, so as to solve the problem of balancing the glass transition temperature, linear expansion coefficient, high transmittance, yellowing resistance, processability and film-forming properties of the encapsulation film, and the warping compensation effect of the film on the chip.

[0007] The technical solution adopted by the present invention is as follows:

[0008] A chip encapsulation film, comprising an epoxy resin, a curing agent and an auxiliary agent; the epoxy resin comprises 72-86% of alicyclic epoxy resin, 3-8% of triglycidyl isocyanurate, 5-10% of silicone-modified epoxy resin and 6-10% of epoxy resin toughening agent, and the total fraction of the epoxy resin is 100%; the curing agent comprises 80-87% of styrene-maleic anhydride polymer, 3-5% of special anhydride curing agent and 10-15% of hexahydrophthalic anhydride, and the total fraction of the curing agent is 100%; the auxiliary agent comprises an accelerator, a defoamer, a wetting agent, a leveling agent, and a curing agent. agent and solvent; wherein, the epoxy resin and the curing agent react in equal equivalents, the mass ratio is 100:(120-135), the mass ratio of the epoxy resin and the accelerator is 100:(1-2), the mass ratio of the epoxy resin and the defoaming agent is 100:(0.1-0.2), the mass ratio of the epoxy resin and the wetting agent is 100:(0.1-0.2), the mass ratio of the epoxy resin and the leveling agent is 100:(0.1-0.2), and the mass ratio of the epoxy resin + curing agent to the solvent is 100:(70-75).

[0009] A further technical solution is that the alicyclic epoxy resin is in liquid or solid state, and has an epoxy equivalent of 120 to 180 g / eq. The alicyclic epoxy resin is any one of EHPE3150, EHPE3150CE and TTA3150.

[0010] A further technical solution is that the special silicone modified epoxy resin is a silicone resin containing epoxy groups at the end or side chain, and the epoxy equivalent is 180 to 700 g / eq. The special silicone modified epoxy resin is any one of EPSI-3201S, EPSI-3866, EPSI-6808, ALBIFLEX 296, and ALBIFLEX 348.

[0011] A further technical solution is that the epoxy resin toughening agent is a flexible resin and is any one of PB3600, EP-4000, SQP-40AM32 and ET 9002X60.

[0012] A further technical solution is that the number average molecular weight of the styrene-maleic anhydride polymer curing agent is 3000-6000 g / mol. The styrene-maleic anhydride polymer curing agent is any one or two of SMA EF30, SMA EF60 and SMA EF40.

[0013] A further technical solution is that the special anhydride curing agent is any one of H-TMAn and TBN-100.

[0014] A further technical solution is that the accelerator is any one of U-CAT SA-102, PX-4MP, U-CAT 5003, U-CAT 12XD and AO-4; the defoamer is any one of BYK-A515, BYK-A530, 100F and KS-603; the wetting agent is any one of BYK-354, BYK-358N, BYK-306 and BYK-333; the leveling agent is any one of BYK-310, TEGO Glide 450 and BYK-335; and the solvent is any two or three of butyl acetate, butanone, propylene glycol methyl ether acetate and ethylene glycol methyl ether.

[0015] The present invention also discloses a method for preparing the aforementioned chip encapsulation film, comprising the following steps:

[0016] Put epoxy resin, curing agent and auxiliary agent into a planetary mixer in sequence, heat the planetary mixer to 60-80°C, stir for 1-2 hours, cool to room temperature, and obtain a glue solution with a solid content of 50-60%;

[0017] The adhesive solution is transferred to a coating machine, and the coating machine coats the adhesive solution at an oven temperature of 50 to 70° C., a running speed of 1 to 2 m / min, and a winding tension of 50 to 90 N to obtain a continuous dense adhesive film with a thickness of 50 to 200 μm;

[0018] Winding and die-cutting make the film in the form of rolls or sheets;

[0019] The adhesive film is adhered to the chip or substrate, heated at 90-110° C. for 1-2 hours, and then heated at 150-180° C. for 3-5 hours to cure to obtain a chip encapsulation adhesive film.

[0020] A further technical solution is to use a vacuum lamination process to adhere the adhesive film to the chip or substrate.

[0021] The present invention also discloses the application of the aforementioned chip encapsulation film in chip encapsulation. Specifically, the chip encapsulation film is attached to a substrate, which may be made of glass or metal, and the lower end of the substrate is connected to a photosensitive material and an RDL layer. After the chip encapsulation film is cured, it effectively compensates for the warping of the entire chip based on the characteristic that the linear expansion coefficient is higher than 100ppm / ℃.

[0022] The beneficial effects of the embodiments of the present invention are as follows:

[0023] (I) The chip encapsulation film of the present invention comprises an epoxy resin, a curing agent and an auxiliary agent, wherein the epoxy resin comprises 72-86% of alicyclic epoxy resin, 3-8% of triglycidyl isocyanurate, 5-10% of organosilicon-modified epoxy resin and 6-10% of epoxy resin toughening agent, and the total fraction of the epoxy resin is 100%; the curing agent comprises 80-87% of styrene-maleic anhydride polymer, 3-5% of special acid anhydride curing agent and 10-15% of hexahydrophthalic anhydride, and the total fraction of the curing agent is 100%; the auxiliary agent comprises an accelerator, a defoaming agent, a wetting agent , leveling agent and solvent; wherein, the epoxy resin and curing agent react in equal amounts, the mass ratio is 100:(120-135), the mass ratio of epoxy resin and accelerator is 100:(1-2), the mass ratio of epoxy resin and defoamer is 100:(0.1-0.2), the mass ratio of epoxy resin and wetting agent is 100:(0.1-0.2), the mass ratio of epoxy resin and leveling agent is 100:(0.1-0.2), the mass ratio of epoxy resin + curing agent to solvent is 100:(70-75). The above materials are heated, stirred, dissolved and mixed to form a glue solution, which is then processed into a continuous and dense glue film by a coating machine. The film is cured by (90-110℃) / (1-2h)+(150-180℃) / (3-5h). The obtained epoxy resin film has high light transmittance, high temperature resistance, high adhesion, and excellent film-forming properties. It is especially suitable for special chip packaging fields with high requirements on product warpage. At the same time, it makes up for the defects and shortcomings of traditional high powder filling films and expands the application of epoxy resin in the packaging industry.

[0024] (II) The present invention preferably uses a heat-resistant resin and a heat-resistant curing system. Specifically, the present invention uses a special alicyclic epoxy resin as the main resin to prevent the epoxy resin film from yellowing and deteriorating under high temperature conditions. The present invention preferably uses an SMA resin with excellent heat resistance as a curing agent, and is supplemented with a special curing agent, such as H-TMAn and TBN-100, to further enhance the heat resistance of the epoxy resin film.

[0025] (III) The chip packaging process involves many specific applications. Some packaging factories use transparent packaging film materials as chip packaging materials. The PI photosensitive material under the transparent film material is cross-linked by laser excitation. The better the transparency of the transparent packaging film, the higher the laser excitation efficiency. Therefore, the transparency of the product is a key indicator. In order to achieve the requirement of high light transmittance, the present invention selects raw materials with high light transmittance, and strictly evaluates the temperature resistance and aging resistance of the raw materials. On this basis, the best combination of resin / curing agent system is selected, and an accelerator with moderate activity and good temperature resistance is matched, such as any one of U-CAT SA-102, PX-4MP, U-CAT 5003, U-CAT 12XD and AO-4, to obtain a highly transparent and highly heat-resistant epoxy resin film.

[0026] (IV) The product proposed by the present invention is presented in the form of a film material. The film-forming property of the product is an important indicator and a key link that directly affects the on-site use of customers. The present invention uses a compound of solid raw materials and liquid raw materials to maximize the film-forming property of epoxy resin. More importantly, a toughening resin with excellent film-forming effect is selected, such as any one of PB3600, EP-4000, SQP-40AM32 and ET 9002X60. These materials can not only give the epoxy resin better film-forming property, but also reduce the brittleness of the epoxy resin, which well solves the problem of poor film-forming property of epoxy resin.

[0027] (V) Different from conventional epoxy resin packaging materials, the technical route provided by the present invention uses special raw materials and additives, and the linear expansion coefficient of the product is higher than 100ppm / ℃, which is helpful for chip warping compensation. Specifically, a highly transparent warping compensation film is attached to a substrate, which can be a glass material or a metal material, and the lower end of the substrate is connected to the photosensitive material and the RDL layer. After the warping compensation film is cured, due to its own characteristics, it effectively compensates for the warping of the entire chip, thereby minimizing the warping of the chip to the greatest extent and improving the product yield and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a flow chart of the method for preparing the chip packaging film. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0030] First embodiment:

[0031] The chip encapsulation film includes epoxy resin, curing agent and additives.

[0032] The epoxy resin includes 77 parts of alicyclic epoxy resin, 5 parts of triglycidyl isocyanurate, 8 parts of organosilicon-modified epoxy resin and 10 parts of epoxy resin toughening agent. Among them, the alicyclic epoxy resin is EHPE3150. The special organosilicon-modified epoxy resin is ALBIFLEX 296. The epoxy resin toughening agent is PB3600.

[0033] The curing agent includes 103.75 parts of styrene-maleic anhydride polymer, 6.25 parts of special anhydride curing agent and 15 parts of hexahydrophthalic anhydride, wherein the styrene-maleic anhydride polymer curing agent is SMA EF30 and the special anhydride curing agent is H-TMAn.

[0034] The additives include 1.5 parts of accelerator, 0.2 parts of defoamer, 0.1 parts of wetting agent, 0.2 parts of leveling agent, 101.25 parts of butyl acetate and 67.5 parts of propylene glycol methyl ether acetate. Among them, the accelerator is U-CAT SA-102, the defoamer is BYK-A530, the wetting agent is BYK-358N, and the leveling agent is BYK-310.

[0035] The method for preparing a chip encapsulation film comprises the following steps:

[0036] Step S1, put the above-mentioned epoxy resin, curing agent and auxiliary agent in parts by weight into a planetary mixer in sequence, heat the planetary mixer to 70° C., heat and stir for 1.5 hours, cool to room temperature, and obtain a glue solution with a solid content of 56.6%.

[0037] Step S2, the glue solution is transferred to a coating machine, and the coating machine is coated at an oven temperature of 65°C, a running speed of 1m / min and a winding tension of 50N to obtain a continuous dense glue film with a thickness of 100μm.

[0038] Step S3, rolling and die-cutting, so that the film is presented in the form of roll or sheet.

[0039] Step S4, the adhesive film is adhered to the chip or substrate, heated at 100° C. for 1.5 hours, and then heated at 180° C. for 3 hours to cure to obtain a chip encapsulation adhesive film.

[0040] Specifically, the adhesive film is adhered to the chip or substrate using a vacuum film bonding process.

[0041] Second embodiment:

[0042] The chip encapsulation film includes epoxy resin, curing agent and additives.

[0043] The epoxy resin includes 86 parts of alicyclic epoxy resin, 3 parts of triglycidyl isocyanurate, 5 parts of silicone-modified epoxy resin and 6 parts of epoxy resin toughening agent. Among them, the alicyclic epoxy resin is EHPE3150CE. The special silicone-modified epoxy resin is EPSI-3866. The epoxy resin toughening agent is SQP-40AM32.

[0044] The curing agent includes 111.8 parts of styrene-maleic anhydride polymer, 5.2 parts of special anhydride curing agent and 13 parts of hexahydrophthalic anhydride. Among them, the styrene-maleic anhydride polymer curing agent is SMA EF60. The special anhydride curing agent is TBN-100.

[0045] The additives include 1.95 parts of accelerator, 0.1 parts of defoamer, 0.2 parts of wetting agent, 0.1 parts of leveling agent, 115 parts of butanone and 46 parts of ethylene glycol methyl ether. Among them, the accelerator is U-CAT 12XD, the defoamer is KS-603, the wetting agent is BYK-306, and the leveling agent is TEGO Glide 450.

[0046] The method for preparing a chip encapsulation film comprises the following steps:

[0047] Step S1, put the above-mentioned epoxy resin, curing agent and auxiliary agent in parts by weight into a planetary mixer in sequence, heat the planetary mixer to 60°C, heat and stir for 2 hours, cool to room temperature, and obtain a glue solution with a solid content of 58.3%.

[0048] Step S2, transferring the adhesive solution to a coating machine, and coating the adhesive solution at an oven temperature of 70° C., a running speed of 2 m / min, and a winding tension of 75 N to obtain a continuous dense adhesive film with a thickness of 50 μm.

[0049] Step S3, rolling and die-cutting, so that the film is presented in the form of roll or sheet.

[0050] Step S4, the adhesive film is adhered to the chip or substrate, heated at 95° C. for 1 hour, and then heated at 150° C. for 5 hours to cure to obtain a chip encapsulation adhesive film.

[0051] Specifically, the adhesive film is adhered to the chip or substrate using a vacuum film bonding process.

[0052] Third embodiment:

[0053] The chip encapsulation film includes epoxy resin, curing agent and additives.

[0054] The epoxy resin includes 74 parts of alicyclic epoxy resin, 8 parts of triglycidyl isocyanurate, 10 parts of silicone-modified epoxy resin and 8 parts of epoxy resin toughening agent. Among them, the alicyclic epoxy resin is TTA3150. The special silicone-modified epoxy resin is EPSI-3201S. The epoxy resin toughening agent is ET9002X60.

[0055] The curing agent includes 103.32 parts of styrene-maleic anhydride polymer, 3.78 parts of special anhydride curing agent and 18.9 parts of hexahydrophthalic anhydride, wherein the styrene-maleic anhydride polymer curing agent is SMA EF40 and the special anhydride curing agent is H-TMAn.

[0056] The additives include 1.01 parts of accelerator, 0.1 parts of defoamer, 0.1 parts of wetting agent, 0.2 parts of leveling agent, 119.78 parts of butyl acetate and 45.2 parts of ethylene glycol methyl ether. Among them, the accelerator is PX-4MP. The defoamer is BYK-A515. The wetting agent is BYK-333. The leveling agent is BYK-335.

[0057] The method for preparing a chip encapsulation film comprises the following steps:

[0058] Step S1, put the above-mentioned epoxy resin, curing agent and auxiliary agent in parts by weight into a planetary mixer in sequence, heat the planetary mixer to 80°C, heat and stir for 1 hour, cool to room temperature, and obtain a glue solution with a solid content of 57.3%.

[0059] Step S2, transferring the adhesive solution to a coating machine, and coating the adhesive solution at an oven temperature of 60° C., a running speed of 1.5 m / min, and a winding tension of 90 N to obtain a continuous dense adhesive film with a thickness of 150 μm.

[0060] Step S3, rolling and die-cutting, so that the film is presented in the form of roll or sheet.

[0061] Step S4, the adhesive film is adhered to the chip or substrate, heated at 90° C. for 2 hours, and then heated at 170° C. for 4 hours to cure to obtain a chip encapsulation adhesive film.

[0062] Specifically, the adhesive film is adhered to the chip or substrate using a vacuum film bonding process.

[0063] The epoxy resin films prepared in the first to third embodiments were tested for product performance, and the results are shown in Table 1.

[0064] Table 1

[0065]

[0066]

[0067] The test method is as follows:

[0068] Light transmittance: According to GB / T 2410-2008, 25℃.

[0069] Temperature resistance: baked at 180℃, visually observe the yellowing time.

[0070] Glass transition temperature: According to GB / T 1634-2004, using differential scanning calorimeter.

[0071] Linear expansion coefficient: According to GB / T2572-2005. Among them, ɑ1 is the linear expansion coefficient of the low temperature range (30~80℃), and ɑ2 is the linear expansion coefficient of the high temperature range (120~180℃).

[0072] Elastic modulus: According to GB / T 2567-2008, 25℃.

[0073] Chemical resistance: The weight gain after immersion in dimethyl sulfoxide solution for 24 hours was tested using the weight method.

[0074] Film adhesion: According to GB / T 9286-1998, 25℃.

[0075] PCT water absorption: Based on GB / T10586-2006, 121°C, RH100 / 24h.

[0076] It can be seen from the data in Table 1 that the epoxy resin films prepared in the three embodiments provided by the present invention have a light transmittance higher than 85%, and the yellowing time at 180°C is more than 16 hours. The glass transition temperatures of the three embodiments are relatively high, all exceeding 178°C, the linear expansion coefficient ɑ1 is greater than 100ppm / °C, the chemical resistance of dimethyl sulfoxide is less than 0.4%, and the film adhesion is less than or equal to level 3, which can meet the requirements of specific advanced packaging films for light transmittance, temperature resistance and adhesion.

[0077] At the same time, the epoxy resin films prepared in the three embodiments are highly light-transmitting films and have high temperature resistance. They can be used as process films for laser-induced photosensitive materials. The epoxy resin films have high adhesion to the substrate and can achieve effective bonding. At the same time, the epoxy resin films have excellent chemical resistance and very low water absorption, which meets the special requirements for special film materials in the field of advanced packaging.

[0078] In addition, as a unique technology, the epoxy resin films of the three embodiments have both high glass transition temperature and high linear expansion coefficient ɑ1, which can not only meet the reliability requirements of the packaging industry, but also reduce the overall deformation of the chip components, play a good warping compensation role, and solve the problems that plague the development of the industry. Among them, the first embodiment has good comprehensive performance and moderate cost performance. The second embodiment has the characteristics of high glass transition temperature and high temperature resistance. The third embodiment has high flexibility and high light transmittance, as well as better warping compensation effect. Customers can choose appropriate products according to actual needs.

[0079] The first comparison:

[0080] The alicyclic epoxy resin EHPE3150 in the first embodiment is replaced by bisphenol A epoxy resin E-51 to ensure that the molar ratio of epoxy resin to curing agent is 1:1. The rest is the same as the first embodiment.

[0081] Second comparison:

[0082] The triglycidyl isocyanurate in the first embodiment is replaced by alicyclic epoxy resin EHPE3150, and the rest is the same as the first embodiment.

[0083] The third comparison ratio:

[0084] The organosilicon-modified epoxy resin ALBIFLEX 296 in the first embodiment is replaced by alicyclic epoxy resin EHPE3150, and the rest is the same as the first embodiment.

[0085] The fourth comparison ratio:

[0086] The epoxy resin toughening agent PB3600 in the first embodiment is replaced with the alicyclic epoxy resin EHPE3150 to ensure that the molar ratio of the epoxy resin to the curing agent is 1:1. The rest is the same as the first embodiment.

[0087] Fifth comparison ratio:

[0088] The curing agent EF30 in the first embodiment is replaced with a common curing agent hexahydrophthalic anhydride to ensure that the molar ratio of the epoxy resin to the curing agent is 1:1. The rest is the same as the first embodiment.

[0089] The epoxy resin films prepared in the first to fifth comparative examples were tested for product performance, and the results are shown in Table 3.

[0090] Table 2

[0091]

[0092]

[0093] From the data in Table 2, it can be seen that in the first comparative example, the performance of the product changes fundamentally when the alicyclic epoxy resin EHPE3150 is replaced by the bisphenol A epoxy resin E-51. The temperature resistance changes from 16h to 3h, the glass transition temperature decreases from 182.6℃ to 152.2℃, the chemical resistance increases from 0.32% to 1.39%, and the PCT water absorption rate changes from 0.89% to 1.95%. The key indicators of the product show obvious deterioration, which is closely related to the structure of the alicyclic epoxy resin EHPE3150 and the bisphenol A epoxy resin E-51. The alicyclic epoxy resin EHPE3150 is an alicyclic epoxy resin with a ring structure, a dense molecular structure, and a large cross-linking density. The product prepared with the alicyclic epoxy resin EHPE3150 as the raw material has excellent comprehensive performance. Bisphenol A epoxy resin E-51 is a long-chain bisphenol A epoxy resin, which is a universal material. Using bisphenol A epoxy resin E-51 as the main resin, the product has a small cross-linking density and general comprehensive performance. It can be seen that the role of alicyclic epoxy resin EHPE3150 in the present invention is irreplaceable.

[0094] From the data in Table 2, it can be seen that in the second comparative example, triglycidyl isocyanurate is replaced with alicyclic epoxy resin EHPE3150, and the product's indicators such as temperature resistance, chemical resistance, linear expansion coefficient and PCT water absorption rate show a certain degree of deterioration. The reason is that the cross-linking density of the product becomes lower, the number of characteristic groups that resist high temperature and solvents is reduced, and the overall performance deteriorates. Triglycidyl isocyanurate is a trifunctional resin with the characteristics of high cross-linking density and high temperature resistance, and plays an excellent role in special products and special applications. The present invention adds 3-8% triglycidyl isocyanurate to the epoxy resin, the purpose of which is to give the product unique properties through the special structure of triglycidyl isocyanurate. It can be seen that triglycidyl isocyanurate is indispensable in the formulation system.

[0095] From the data in Table 2, it can be seen that in the third comparative example, the organosilicon-modified epoxy resin ALBIFLEX 296 is replaced with the alicyclic epoxy resin EHPE3150, and the silicon-oxygen structural unit is missing in the polymerization system, so the temperature resistance and chemical resistance of the product are reduced. The organosilicon-modified epoxy resin ALBIFLEX 296 has a certain flexibility. In the absence of the organosilicon-modified epoxy resin ALBIFLEX 296, the glass transition temperature of the product is increased and the linear expansion coefficient is reduced. From the results in Table 2, it can also be seen that the elastic modulus of the third comparative example is increased and the PCT water absorption rate is reduced. These two indicators are good. Therefore, the organosilicon-modified epoxy resin ALBIFLEX 296 plays a role in balancing the comprehensive performance of the product. It is necessary to find the optimal dosage of the organosilicon-modified epoxy resin ALBIFLEX296, give full play to its maximum effect, and suppress its disadvantages.

[0096] From the data in Table 2, it can be seen that in the fourth comparative example, the epoxy resin toughener PB3600 is replaced with the alicyclic epoxy resin EHPE3150, the temperature resistance of the product is improved, the modulus, chemical resistance, and PCT water absorption rate are improved, but the linear expansion coefficient of the product is reduced from 115.3ppm / ℃ to 85.2ppm / ℃, and the glass transition temperature is increased to 209.5℃. In this case, the film has almost no warpage compensation effect. An important object of the present invention is to provide a film with warpage compensation effect. The linear expansion coefficient of the product is higher than 100ppm / ℃, and the warpage compensation effect can be reflected. The epoxy resin toughener is the key to achieving this purpose. The epoxy resin toughener used in the present invention is a rubber or rubber-like flexible monomer with good film-forming property and flexibility. Dispersing it in the product can improve the linear expansion coefficient and enhance the warpage compensation effect. It can be seen that the epoxy resin toughener PB3600 is irreplaceable in the formulation system.

[0097] From the data in Table 2, it can be seen that in the fifth comparative example, the curing agent EF30 is replaced with the common curing agent hexahydrophthalic anhydride, and the product's temperature resistance, chemical resistance, film adhesion, PCT water absorption rate and other indicators are reduced to varying degrees, especially the glass transition temperature, which is reduced from 182.6°C to 142.7°C. The degree of performance degradation is quite obvious and cannot meet the high standards and stringent requirements of the advanced packaging industry. These comparative data are concrete manifestations of the important role of EF30. Curing agent is an important component of epoxy resin. The selection of an appropriate curing agent system not only determines the application scenario of the product, but also has a close relationship with the use effect of the product. Unlike conventional curing agents, the curing agent used in the present invention is an SMA system, which is a macromolecular polymer curing agent with a regular structure, high transparency and good temperature resistance obtained by copolymerizing styrene and maleic anhydride. This curing agent can meet the design requirements of the present invention and is also an important raw material in the present invention.

[0098] In summary, the present invention uses alicyclic epoxy resin, triglycidyl isocyanurate, silicone-modified epoxy resin, toughened epoxy resin, special curing agent, accelerator and various additives, through scientific matching and optimization of raw materials, assisted by reasonable processing methods, to obtain an epoxy resin film with high transparency, good temperature resistance, high glass transition temperature, excellent chemical resistance and good hygroscopicity, and the film has excellent warpage compensation effect, is used in the field of advanced packaging, and meets the specific needs of chip processing. The embodiments provided by the present invention have outstanding advantages, can solve technical problems in the industry, and have broad market prospects.

[0099] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A chip encapsulation film, characterized in that: Including epoxy resin, curing agent and additives; The epoxy resin comprises 72-86% of alicyclic epoxy resin, 3-8% of triglycidyl isocyanurate, 5-10% of organosilicon-modified epoxy resin and 6-10% of epoxy resin toughening agent, and the total fraction of the epoxy resin is 100%; The curing agent includes 80-87% of styrene-maleic anhydride polymer, 3-5% of special acid anhydride curing agent and 10-15% of hexahydrophthalic anhydride, and the total fraction of the curing agent is 100%; Additives include accelerators, defoamers, wetting agents, leveling agents and solvents; Among them, the epoxy resin and the curing agent react in equal amounts, with a mass ratio of 100:(120-135), the mass ratio of the epoxy resin and the accelerator is 100:(1-2), the mass ratio of the epoxy resin and the defoaming agent is 100:(0.1-0.2), the mass ratio of the epoxy resin and the wetting agent is 100:(0.1-0.2), the mass ratio of the epoxy resin and the leveling agent is 100:(0.1-0.2), and the mass ratio of the epoxy resin + curing agent to the solvent is 100:(70-75).

2. The chip encapsulation film according to claim 1, characterized in that: The alicyclic epoxy resin is in liquid or solid state, and has an epoxy equivalent of 120 to 180 g / eq.

3. The chip encapsulation film according to claim 1, characterized in that: The special silicone-modified epoxy resin is a silicone resin containing epoxy groups at the end group or the side chain, and the epoxy equivalent is 180 to 700 g / eq.

4. The chip encapsulation film according to claim 1, characterized in that: The epoxy resin toughening agent is a flexible resin.

5. The chip encapsulation film according to claim 1, characterized in that: The number average molecular weight of the styrene-maleic anhydride polymer curing agent is 3000-6000 g / mol, and the styrene-maleic anhydride polymer curing agent is any one or two of SMA EF30, SMA EF60 and SMA EF40.

6. The chip encapsulation film according to claim 1, characterized in that: The special anhydride curing agent is any one of H-TMAn and TBN-100.

7. The chip encapsulation film according to claim 1, characterized in that: The accelerator is any one of U-CAT SA-102, PX-4MP, U-CAT 5003, U-CAT 12XD and AO-4; the defoamer is any one of BYK-A515, BYK-A530, 100F and KS-603; the wetting agent is any one of BYK-354, BYK-358N, BYK-306 and BYK-333; the leveling agent is any one of BYK-310, TEGO Glide 450 and BYK-335; the solvent is any two or three of butyl acetate, butanone, propylene glycol methyl ether acetate and ethylene glycol methyl ether.

8. The method for preparing a chip encapsulation film according to any one of claims 1 to 7, characterized in that: The following steps are involved: Put epoxy resin, curing agent and auxiliary agent into a planetary mixer in sequence, heat the planetary mixer to 60-80°C, stir for 1-2 hours, cool to room temperature, and obtain a glue solution with a solid content of 50-60%; The adhesive solution is transferred to a coating machine, and the coating machine coats the adhesive solution at an oven temperature of 50 to 70° C., a running speed of 1 to 2 m / min, and a winding tension of 50 to 90 N to obtain a continuous dense adhesive film with a thickness of 50 to 200 μm; Winding and die-cutting make the film in the form of rolls or sheets; The adhesive film is adhered to the chip or substrate, heated at 90-110° C. for 1-2 hours, and then heated at 150-180° C. for 3-5 hours to cure to obtain a chip encapsulation adhesive film.

9. The method for preparing the chip encapsulation film according to claim 8, characterized in that: The film is adhered to the chip or substrate using a vacuum lamination process.

10. Use of the chip encapsulation film according to any one of claims 1 to 7 in chip encapsulation.

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