Multilayer thermosetting film and preparation method thereof

Abstract

The invention relates to a multilayer thermosetting film which comprises a reinforcing layer and a bonding layer, and the reinforcing layer comprises the following raw materials in parts by weight: 5-15 parts of polyfunctional epoxy resin, 1-10 parts of amine curing agent, 1-5 parts of special interface resin, 1-5 parts of assistant combination, 50-100 parts of filler and 10-100 parts of solvent; the bonding layer is prepared from the following raw materials in parts by weight: 1 to 40 parts of epoxy resin, 1 to 40 parts of latent curing agent, 1 to 40 parts of vinyl resin combination, 30 to 80 parts of flexible reactive resin, 0.01 part of accelerant, 0.05 part of initiator, 10 to 100 parts of solvent and 1 to 5 parts of assistant combination. The bonding layer has good flowability and cohesiveness and plays a role in bonding.

Description

Technical Field

[0001] The invention relates to the technical field of composite films, and in particular to a multilayer thermosetting film and a preparation method thereof. Background Art

[0002] Chip encapsulation film is a very thin material, usually less than 0.1 micron, with a variety of physical and chemical properties that can improve the performance and stability of the chip. In the chip encapsulation process, the film is used as an encapsulation material, covering the surface of the chip to form a protective layer to prevent the chip from mechanical damage, corrosion, pollution, etc.

[0003] At present, some processes in the chip packaging process require the film material to maintain a high modulus under high temperature (180-260°C) conditions to form a support for the chip and retain the cavity structure; some chip packaging processes require low shrinkage during high temperature curing to achieve low warpage, which requires the film to have good adhesion and fluidity while maintaining uniform thickness. However, the current single-layer film can only specialize in a single characteristic and cannot meet the needs of chip packaging.

[0004] 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

[0005] In view of the deficiencies of the prior art, the present invention discloses a multilayer thermosetting film and a preparation method thereof.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A multi-layer thermosetting film includes a reinforcement layer and a bonding layer;

[0008] The raw materials of the reinforcing layer include, by weight: 5 to 15 parts of multifunctional epoxy resin, 1 to 10 parts of amine curing agent, 1 to 5 parts of special interface resin, 1 to 5 parts of auxiliary agent combination, 50 to 100 parts of filler, and 10 to 100 parts of solvent;

[0009] The raw materials of the bonding layer include, by weight: 1 to 40 parts of epoxy resin, 1 to 40 parts of latent curing agent, 1 to 40 parts of vinyl resin combination, 30 to 80 parts of flexible reactive resin, 0.01 parts of accelerator, 0.05 parts of initiator, 10 to 100 parts of solvent, and 1 to 5 parts of auxiliary agent combination.

[0010] Furthermore, the multifunctional epoxy resin used in the reinforcing layer includes one or more combinations of phenolic epoxy resin, bisphenol A phenolic epoxy resin, trisphenol methane epoxy resin and naphthol phenolic epoxy resin.

[0011] Furthermore, the amine curing agent used in the reinforcing layer includes one or more combinations of diaminodiphenyl ether, diaminodiphenylmethane, metaphenylenediamine and isophoronediamine.

[0012] Furthermore, the interface resin used in the reinforcing layer is an epoxy butadiene silane terpolymer, and the auxiliary agent combination used in the reinforcing layer is a combination of a silane coupling agent and a polyether leveling agent.

[0013] Furthermore, the filler used in the reinforcement layer is one or more combinations of spherical silica or spherical alumina.

[0014] Furthermore, the latent curing agent used in the bonding layer includes one or more combinations of dicyandiamide, phenolic resin, cyanate ester, diaminodiphenyl sulfone and modified acid anhydride, and the auxiliary agent combination used in the bonding layer is a combination of a silane coupling agent, a polyether leveling agent, a silicone defoamer and a polyester wetting agent.

[0015] Furthermore, the vinyl resin combination used in the bonding layer includes one or more combinations of vinyl epoxy resin, allyl resin, bismaleimide resin and acrylate resin, and the flexible reactive resin used in the bonding layer includes one or more combinations of reactive polyimide, epoxy modified rubber, carboxyl modified rubber, acrylic rubber and anhydride modified elastomer.

[0016] Furthermore, the accelerator used in the bonding layer is an imidazole accelerator; and the initiator is a peroxide.

[0017] A method for preparing a multilayer thermosetting film comprises the following steps:

[0018] Step S1, preparing the reinforcing layer glue: adding a multifunctional epoxy resin, an amine curing agent, a filler, a special interface resin, an auxiliary agent combination and a solvent into a reaction kettle in proportion, and stirring until they are uniformly dissolved;

[0019] Step S2, preparing adhesive for the bonding layer: adding epoxy resin, latent curing agent, vinyl resin combination, flexible reactive resin, accelerator, initiator, solvent and auxiliary agent combination into a reaction kettle in proportion, and stirring until they are evenly dissolved;

[0020] Step S3, reinforcement layer coating: coating the adhesive on the surface of the base film by a coating machine to form a reinforcement layer, and baking at a temperature range of 10 to 80° C. for 1 to 60 minutes. After baking, the composite release film obtains a single-layer film;

[0021] Step S4, coating of adhesive layer: removing the release film from the film material obtained in S3, coating the adhesive layer glue on the surface of the reinforcing layer by using a rotary coater or screen printing, and then baking at a temperature range of 50 to 100° C. for 1 to 50 minutes. After baking, the reinforcing layer remains soft and uncured, and a double-layer film is formed after compounding the release film;

[0022] Step S5, removing the base film on the double-layer film reinforcement layer obtained in S4, repeating step S4, and forming a three-layer film with the composite release film;

[0023] Step S6: alternately stack the double-layer film obtained in S4 or the multi-layer film obtained in S5 with a flat steel plate, and place them in a vacuum press at a pressure of 10-100 PSI and 50-100° C. for 4-8 hours.

[0024] A method for detecting a multilayer thermosetting film comprises the following steps:

[0025] Step S1, cutting the multilayer film into square pieces with a side length of 20 mm, a total of S pieces, where S can be 5-50;

[0026] Step S2, the square sheets are laminated together, and a vacuum laminating machine is used to remove air bubbles and form a thick film, and the test thickness is A micrometers;

[0027] Step S3, placing the thick film into a hot pressing device, evacuating the film, and drying the film in an oven at a constant temperature of 80°C-150°C for 1-5 minutes at a pressure of 1Kg / cm2;

[0028] Step S4, test S3, the thickness of the solidified material is B micrometers, and the fluidity is characterized by: L = (AB) / (S*A) * 100. If the L measured for the sample is 10-60, the sample is qualified.

[0029] The beneficial effects of the present invention are as follows:

[0030] 1. The reinforcement layer uses multifunctional epoxy and amine curing agents, which can be quickly cured at medium and low temperatures (below 120°C). It is completely cured during the first vacuum pressing (lamination). The use of aromatic amines and alicyclic amines can quickly reach a high glass transition temperature Tg and a low thermal expansion coefficient CTE. When used in the subsequent packaging process, there is no reaction process in the reinforcement layer resin during the curing process, so there is no shrinkage and warping. Under the special curing agent combination, the glass transition temperature of the reinforcement layer reaches 380°C, and the reinforcement layer maintains a high modulus of 5Gpa in a high temperature environment of 280°C. The high modulus at high temperature supports the chip and ensures that the cavity structure of the chip will not collapse during reflow soldering, so that the cavity is preserved. In addition, the reinforcement layer is a completely cured product. When used in packaging, there is no glue flow in this part, so the thickness uniformity is effectively controlled.

[0031] 2. The bonding layer uses a latent thermosetting resin combination, which can provide adhesion for the multilayer film and achieve the effect of bonding the wafer. After the bonding layer is attached to the surface of the wafer, vacuum and heating make the bonding layer sticky and flow to wet the surface of the wafer and fill the gaps of the chip surface circuit. Then a high-temperature post-curing process is carried out, and the fully cured bonding layer resin is firmly bonded to the chip. Soft reactive resins can provide higher bonding force while providing low modulus and low shrinkage, reduce stress after high-temperature curing, and prevent high stress caused by cold and hot shocks or moisture absorption, which may cause loose bonding and detachment from the wafer. The bonding layer is the key to ensuring that the product passes the reliability test.

[0032] 3. During the coating process of the reinforcing layer and the bonding layer, the film is kept non-sticky at the temperature when it is pre-laminated to ensure that the two will not wrinkle or generate bubbles during the subsequent lamination. During the pre-lamination process, the two reinforcing layers and the bonding layer are initially non-sticky. The temperature is slowly increased under vacuum pressure conditions, and the reinforcing layers and the bonding layers gradually become sticky, expelling the air between the films without generating wrinkles.

[0033] 4. The interface resin is epoxy butadiene silane terpolymer. After use, an interface layer is formed on the surface of the reinforcement layer. This interface layer is a polymerized structure of butadiene and silane, which can prevent the high-activity curing agent of the reinforcement layer from being freed into the bonding layer after bonding, causing the bonding layer resin to solidify and lose the bonding effect. At the same time, the interface layer reacts with the vinyl resin and initiator in the bonding layer, thereby enhancing the bonding force between the layers of the multilayer film. The combination of additives used in the reinforcement layer can promote the rapid leveling of the interface resin to form an interface layer.

[0034] 5. Using a vacuum press can ensure that the film material will not warp, and exhaust will not cause local delamination of the film. The pressing process can enable the reinforcement layer to complete the cross-linking reaction, while the bonding layer does not undergo cross-linking reaction, thereby achieving the functions of reinforcement layer support and bonding layer bonding.

[0035] 6. A combination of additives used in the bonding layer. It helps the vinyl resin and initiator to quickly level and wet the interface resin of the reinforcement layer, and form a firm interface after reaction.

[0036] 7. Because the multilayer film is composed of a fully cured reinforcement layer and an uncured bonding layer. The presence of the reinforcement layer makes it impossible to quickly test the gel time and rheology of the bonding layer to characterize the fluidity and filling properties of the film material. Therefore, a method for testing the fluidity and filling properties of the bonding layer of a multilayer thermosetting film is provided. This method is fast and suitable for online testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the steps for preparing a multilayer thermosetting film.

[0038] Figure 2 Schematic diagram of the detection method steps for multilayer thermosetting films DETAILED DESCRIPTION

[0039] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0040] Embodiment 1:

[0041] A multi-layer thermosetting film includes a reinforcement layer and a bonding layer.

[0042] The raw materials of the reinforcing layer include, by weight: 5 parts of trisphenol methane type epoxy resin Shandong (Shengquan SQTN333), 3 parts of epoxy butadiene silane terpolymer, 0.5 parts of silane coupling agent KH550, 0.5 parts of leveling agent BYK346, 1 part of diaminodiphenyl ether (Wuxi Shaohui), 60 parts of spherical alumina (Suzhou Jinyi QY2) and 10 parts of butanone.

[0043] The raw materials of the bonding layer include, by weight: 5 parts of trisphenol methane epoxy resin (Shandong Shengquan SQTN333), 1 part of dicyandiamide (Wengjiang Reagent), 3 parts of bismaleimide (Dongcai Technology DFE936), 5 parts of vinyl epoxy resin (Swancor 901), 50 parts of reactive polyimide (Wuxi Shaohui), 0.01 parts of 2-methylimidazole Wuxi Shaohui, 0.05 parts of 2,4-di-tert-butyl peroxide isopropylbenzene (Wengjiang Chemical), 0.5 parts of silane coupling agent KH560, 0.5 parts of leveling agent BYK346, 0.5 parts of defoaming agent BYK080, 0.5 parts of succinate wetting agent BK-333 (Hengyu Chemical).

[0044] The preparation method is as follows: Figure 1 As shown, the following steps are included:

[0045] Step S1, reinforcement layer preparation: 5 parts of trisphenol methane epoxy resin Shandong (Shengquan SQTN333), 1 part of diaminodiphenyl ether (Wuxi Shaohui), 60 parts of spherical alumina (Suzhou Jinyi QY2) and 10 parts of butanone are added into a reaction kettle in proportion, stirred until dissolved evenly, and then 3 parts of epoxy butadiene silane terpolymer, 0.5 parts of silane coupling agent KH550, and 0.5 parts of leveling agent BYK346 are added, and stirring is continued before use.

[0046] Step S2, adhesive layer preparation, 5 parts of trisphenol methane epoxy resin (Shandong Shengquan SQTN333), 1 part of dicyandiamide (Wengjiang reagent), 3 parts of bismaleimide (Dongcai Technology DFE936), 5 parts of vinyl epoxy resin (Swancor 901), 50 parts of reactive polyimide (Wuxi Shaohui), 0.01 parts of 2-methylimidazole Wuxi Shaohui, 0.05 parts of 2,4-di-tert-butyl peroxide isopropylbenzene (Wengjiang Chemical) were added into the reaction kettle in proportion, stirred until dissolved evenly, and then 0.5 parts of silane coupling agent KH560, 0.5 parts of leveling agent BYK346, 0.5 parts of defoamer BYK080, 0.5 parts of succinate wetting agent BK-333 (Hengyu Chemical) were added. Stir until before use.

[0047] Step S3, reinforcement layer coating: The adhesive is coated on the surface of the base film by a coating machine to form a reinforcement layer. The gap of the coating machine's scraper is 200um, and the base film uses a 50um low-silicon release film. Then it is baked, and the oven temperature is set to 40 / 80 / 100 / 105 / 105 / 105 / 60℃, the line speed is 1m / min, and the baking time is 50 minutes. The composite release film obtains a single-layer film.

[0048] Step S4, adhesive layer coating: remove the release film from the film obtained in S3 and fix it on a spin coater, drop the glue prepared in S2 on the center, and spin coater at a speed of 6000 rpm. Then evacuate and bake at 100°C for 30 minutes. Then attach the release film to form a double-layer film.

[0049] Step S5, repeat step S4 to obtain a three-layer film.

[0050] The multilayer films obtained in steps S6, S4 and S5 are alternately stacked with flat steel plates and placed in a vacuum press at a pressure of 10-100 PSI and 50-100° C. for 4-8 hours.

[0051] Its detection methods, such as Figure 2 As shown, the following steps are included:

[0052] Step S1, cutting the multilayer film into square pieces with a side length of 20 mm, a total of S pieces, which can be 5-50, and S is 20 in this embodiment.

[0053] Step S2, the square sheets are laminated together, and a vacuum laminating machine is used to remove air bubbles and form a thick film. The test thickness is A microns, and A is 600.

[0054] Step S3: Place the thick film into a hot pressing device, evacuate, and place in an oven at 80°C-150°C for 1-5 minutes at a pressure of 1Kg / cm 2 .

[0055] Step S4, test S3, the thickness of the solidified material obtained is B micrometers, and B is 240.

[0056] The fluidity is characterized by: L = (AB) / (S*A) * 100, and specifically L is 30, which is in the range of 10 to 60, proving that the product fluidity is qualified.

[0057] Embodiment 2:

[0058] A multi-layer thermosetting film includes a reinforcement layer and a bonding layer.

[0059] The raw materials of the reinforcing layer include, by weight: 5 parts of trisphenol methane type epoxy resin (Shandong Shengquan SQTN333), 3 parts of epoxy butadiene silane terpolymer, 0.5 parts of silane coupling agent KH550, 0.5 parts of leveling agent BYK346, 1 part of isophorone diamine (Wuxi Shaohui), 60 parts of spherical alumina (Suzhou Jinyi QY2) and 10 parts of butanone.

[0060] The raw materials of the bonding layer include, by weight: 5 parts of trisphenol methane epoxy resin (Shandong Shengquan SQTN333), 6 parts of cyanate ester (Yangzhou Tianqi C01PS), 3 parts of bismaleimide (Dongcai Technology DFE936), 5 parts of vinyl epoxy resin (Swancor 901), 50 parts of reactive polybutadiene (Caoda JP200), 0.01 parts of imidazole C11Z-A (Wuxi Shaohui), 0.05 parts of 2,4-di-tert-butyl peroxide isopropylbenzene (Wengjiang Chemical), 20 parts of solvent butanone, 0.5 parts of silane coupling agent KH560, 0.5 parts of leveling agent BYK346, 0.5 parts of defoaming agent BYK080, and 0.5 parts of succinate wetting agent BK-333 (Hengyu Chemical).

[0061] The preparation method is as follows: Figure 1 As shown, the following steps are included:

[0062] Step S1, reinforcement layer preparation: 5 parts of trisphenol methane epoxy resin (Shandong Shengquan SQTN333), 1 part of isophorone diamine (Wuxi Shaohui), 60 parts of spherical alumina (Suzhou Jinyi QY2) and 10 parts of butanone are added into a reaction kettle in proportion and stirred until dissolved evenly. Then, 3 parts of epoxy butadiene silane terpolymer, 0.5 parts of silane coupling agent KH550 and 0.5 parts of leveling agent BYK346 are added and stirred continuously before use.

[0063] Step S2, adhesive layer preparation, 5 parts of trisphenol methane epoxy resin (Shandong Shengquan SQTN333), 6 parts of cyanate (Yangzhou Tianqi C01PS), 3 parts of bismaleimide (Dongcai Technology DFE936), 5 parts of vinyl epoxy resin (Swancor901), 50 parts of reactive polybutadiene (Caoda JP200), 0.01 parts of imidazole C11Z-A (Wuxi Shaohui), 0.05 parts of 2,4-di-tert-butyl peroxide isopropylbenzene (Wengjiang Chemical), 20 parts of solvent butanone are added into the reaction kettle in proportion, stirred until dissolved evenly, and then 0.5 parts of silane coupling agent KH560, 0.5 parts of leveling agent BYK346, 0.5 parts of defoaming agent BYK080, 0.5 parts of succinate wetting agent BK-333 (Hengyu Chemical) are added. Stir until before use.

[0064] Step S3, reinforcement layer coating: The adhesive is coated on the surface of the base film by a coating machine to form a reinforcement layer. The gap of the coating machine's scraper is 200um, and the base film uses a 50um low-silicon release film. Then it is baked, and the oven temperature is set to 40 / 80 / 100 / 105 / 105 / 105 / 60℃, the line speed is 1m / min, and the baking time is 50 minutes. The composite release film obtains a single-layer film.

[0065] Step S4, adhesive layer coating: remove the release film from the film obtained in S3 and fix it on a spin coater, drop the glue prepared in S2 on the center, and spin coater at a speed of 6000 rpm. Then evacuate and bake at 100°C for 30 minutes. Then attach the release film to form a double-layer film.

[0066] Step S5, repeat step S4 to obtain a three-layer film.

[0067] The multilayer films obtained in steps S6, S4 and S5 are alternately stacked with flat steel plates and placed in a vacuum press at a pressure of 10-100 PSI and 50-100° C. for 4-8 hours.

[0068] Its detection methods, such as Figure 2 As shown, the following steps are included:

[0069] Step S1, cutting the multilayer film into square pieces with a side length of 20 mm, a total of S pieces, which can be 5-50, S is 20.

[0070] Step S2, the square sheets are laminated together, and a vacuum laminating machine is used to remove air bubbles and form a thick film. The test thickness is A microns, and A is 600.

[0071] Step S3, placing the thick film into a hot pressing device, evacuating the film, and drying it in an oven at a constant temperature of 80°C-150°C for 1-5 minutes at a pressure of 1Kg / cm2.

[0072] Step S4, test S3, the thickness of the solidified material obtained is B micrometers, and B is 240.

[0073] The fluidity is characterized by: L = (AB) / (S*A) * 100, L is 30, which is in the range of 10 to 60, proving that the product fluidity is qualified.

[0074] Embodiment 3:

[0075] The difference from Example 1 is that the multifunctional epoxy resin is a phenolic epoxy resin.

[0076] Embodiment 4:

[0077] The difference from Example 1 is that the multifunctional epoxy resin is bisphenol A novolac epoxy resin.

[0078] Embodiment 5:

[0079] The difference from Example 1 is that the multifunctional epoxy resin is naphthol novolac epoxy resin.

[0080] Embodiment 6:

[0081] The difference from Example 1 is that the amine curing agent is diaminodiphenylmethane.

[0082] Embodiment 7:

[0083] The difference from Example 1 is that the amine curing agent is isophoronediamine.

[0084] Embodiment 8:

[0085] The difference from Example 1 is that the latent curing agent is phenolic resin.

[0086] Embodiment 9:

[0087] The difference from Example 1 is that the latent curing agent is diaminodiphenyl sulfone.

[0088] Embodiment 10:

[0089] The difference from Example 1 is that the latent curing agent is an acid anhydride.

[0090] Embodiment 11:

[0091] The difference from Example 1 is that the vinyl resin combination is a vinyl resin combination.

[0092] Embodiment 12:

[0093] The difference from Example 1 is that the vinyl resin combination is an allyl resin.

[0094] Embodiment 13:

[0095] The difference from Example 1 is that the vinyl resin is combined with an acrylic resin.

[0096] Embodiment 14:

[0097] The difference from Example 1 is that the flexible reactive resin is epoxy-modified rubber.

[0098] Embodiment 15:

[0099] The difference from Example 1 is that the flexible reactive resin is carboxyl-modified rubber.

[0100] Embodiment 16:

[0101] The difference from Example 1 is that the flexible reactive resin is acrylic rubber.

[0102] Embodiment 17:

[0103] The difference from Example 1 is that the flexible reactive resin is an anhydride-modified elastomer.

[0104] The products prepared in Examples 3 to 17 have the same performance as the product prepared in Example 1, and Example 1 is taken as a representative.

[0105] Comparative Example:

[0106] A multi-layer thermosetting film includes a reinforcement layer and a bonding layer.

[0107] The raw materials of the reinforcing layer include, by weight: 5 parts of Shandong epoxy resin (Nan Ya 901), 1 part of diaminodiphenyl ether (Wuxi Shaohui), 60 parts of spherical alumina (Suzhou Jinyi QY2) and 10 parts of butanone.

[0108] The raw materials of the bonding layer include, by weight: 5 parts of epoxy resin (Nan Ya 901), 1 part of dicyandiamide (Wengjiang reagent), and 0.01 part of 2-methylimidazole (Wuxi Shaohui).

[0109] The preparation method is as follows:

[0110] Step S1, reinforcement layer glue preparation: 5 parts of Shandong epoxy resin (Nan Ya 901), 1 part of diaminodiphenyl ether (Wuxi Shaohui), 60 parts of spherical alumina (Suzhou Jinyi QY2) and 10 parts of butanone are put into a reaction kettle in proportion and stirred until dissolved evenly.

[0111] Step S2, preparing adhesive for the bonding layer, adding 5 parts of Shandong epoxy resin (Nan Ya 901), 1 part of dicyandiamide (Wengjiang reagent), and 0.01 part of 2-methylimidazole (Wuxi Shaohui) into a reaction kettle in proportion, and stirring until dissolved evenly.

[0112] Step S3, reinforcement layer coating: The adhesive is coated on the surface of the base film by a coating machine to form a reinforcement layer. The gap of the coating machine's scraper is 200um, and the base film uses a 50um low-silicon release film. Then it is baked, and the oven temperature is set to 40 / 80 / 100 / 105 / 105 / 105 / 60℃, the line speed is 1m / min, and the baking time is 50 minutes. The composite release film obtains a single-layer film.

[0113] Step S4, adhesive layer coating: remove the release film from the film obtained in S3 and fix it on a spin coater, drop the glue prepared in S2 on the center, and spin coater at a speed of 6000 rpm. Then evacuate and bake at 100°C for 30 minutes. Then attach the release film to form a double-layer film.

[0114] Step S5, repeat step S4 to obtain a three-layer film.

[0115] The multilayer films obtained in steps S6, S4 and S5 are alternately stacked with flat steel plates and placed in a vacuum press at a pressure of 10-100 PSI and 50-100°C for 4-8 hours.

[0116] Liquidity test:

[0117] Step S1, cutting the multilayer film into square pieces with a side length of 20 mm, a total of S pieces, which can be 5-50. S is 20

[0118] Step S2, the square sheets are laminated together, and a vacuum laminating machine is used to remove air bubbles and form a thick film. The test thickness is A microns, and A is 600.

[0119] Step S3, placing the thick film into a hot pressing device, evacuating the film, and drying it in an oven at a constant temperature of 80°C-150°C for 1-5 minutes at a pressure of 1Kg / cm2.

[0120] Step S4, test S3, the thickness of the solidified material obtained is B micrometers, and B is 600.

[0121] The fluidity is characterized by: L = (AB) / (S*A) * 100. L = 0, L is not in the range of 10-60, it is a defective product.

[0122] Product performance testing:

[0123] The test results are shown in Table 1:

[0124]

[0125] Table 1

[0126] Test result analysis:

[0127] Example 1 is a multilayer film required for chip packaging cavity support. The reinforcement layer uses a fast-curing high-Tg resin system to provide the multilayer film with high modulus at high temperatures, which supports the chip cavity at high temperatures in applications. The bonding layer uses a reactive polyimide compound epoxy system, and the bonding layer has good adhesion to the chip, copper layer and polyimide adhesive layer. This multilayer film can keep the cavity from collapsing under 6 reflow soldering. The reliability test BHAST passed.

[0128] Example 2 is a multilayer film required for low warpage of chip packaging. The reinforcement layer uses a fast-curing, high-crosslink density, flexible resin system to provide high toughness and low CTE for the multilayer film, which plays a supporting role in the application. The bonding layer uses reactive rubber to reduce the modulus and disperse the shrinkage stress, and uses cyanate ester for good adhesion and low curing shrinkage. This multilayer film can maintain low warpage during the curing process. The reliability test BHAST passed.

[0129] In the comparative example, the multilayer film has no fluidity and adhesion. Since the reinforcing layer does not use the interface resin and the auxiliary agent combination, and the bonding layer does not use the auxiliary agent combination, the high-activity curing agent in the reinforcing layer migrates to the bonding layer to catalyze the bonding layer to cure prematurely. The reliability test BHAST failed.

[0130] 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.

[0131] 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 multilayer thermosetting film, characterized in that: including a reinforcing layer and a bonding layer; The raw materials of the reinforcing layer include, by weight: 5 to 15 parts of multifunctional epoxy resin, 1 to 10 parts of amine curing agent, 1 to 5 parts of special interface resin, 1 to 5 parts of auxiliary agent combination, 50 to 100 parts of filler, and 10 to 100 parts of solvent; The raw materials of the bonding layer include, by weight: 1 to 40 parts of epoxy resin, 1 to 40 parts of latent curing agent, 1 to 40 parts of vinyl resin combination, 30 to 80 parts of flexible reactive resin, 0.01 parts of accelerator, 0.05 parts of initiator, 10 to 100 parts of solvent, and 1 to 5 parts of auxiliary agent combination.

2. The multilayer thermosetting film according to claim 1, characterized in that: The multifunctional epoxy resin used in the reinforcing layer includes one or more combinations of phenolic epoxy resin, bisphenol A phenolic epoxy resin, trisphenol methane epoxy resin and naphthol phenolic epoxy resin.

3. The multilayer thermosetting film according to claim 1, characterized in that: The amine curing agent used in the reinforcing layer includes one or more combinations of diaminodiphenyl ether, diaminodiphenylmethane, metaphenylenediamine and isophoronediamine.

4. The multilayer thermosetting film according to claim 1, characterized in that: The interface resin used in the reinforcing layer is epoxy butadiene silane terpolymer, and the auxiliary agent combination used in the reinforcing layer is a combination of a silane coupling agent and a polyether type leveling agent.

5. The multilayer thermosetting film according to claim 1, characterized in that: The filler used in the reinforcing layer is one or more combinations of spherical silica or spherical alumina.

6. The multilayer thermosetting film according to claim 1, characterized in that: The latent curing agent used in the bonding layer includes one or more combinations of dicyandiamide, phenolic resin, cyanate ester, diaminodiphenyl sulfone and modified acid anhydride, and the auxiliary agent combination used in the bonding layer is a combination of a silane coupling agent, a polyether leveling agent, a silicone defoaming agent and a polyester wetting agent.

7. The multilayer thermosetting film according to claim 1, characterized in that: The vinyl resin combination used in the bonding layer includes one or more combinations of vinyl epoxy resin, allyl resin, bismaleimide resin and acrylate resin, and the flexible reactive resin used in the bonding layer includes one or more combinations of reactive polyimide, epoxy modified rubber, carboxyl modified rubber, acrylic rubber and anhydride modified elastomer.

8. The multilayer thermosetting film according to claim 1, characterized in that: The accelerator used in the bonding layer is an imidazole accelerator; the initiator is a peroxide.

9. A method for preparing a multilayer thermosetting film according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1, preparing the reinforcing layer glue: adding a multifunctional epoxy resin, an amine curing agent, a filler, a special interface resin, an auxiliary agent combination and a solvent into a reaction kettle in proportion, and stirring until they are uniformly dissolved; Step S2, preparing adhesive for the bonding layer: adding epoxy resin, latent curing agent, vinyl resin combination, flexible reactive resin, accelerator, initiator, solvent and auxiliary agent combination into a reaction kettle in proportion, and stirring until they are evenly dissolved; Step S3, reinforcement layer coating: coating the adhesive on the surface of the base film by a coating machine to form a reinforcement layer, and baking at a temperature range of 10 to 80° C. for 1 to 60 minutes. After baking, the composite release film obtains a single-layer film; Step S4, coating of adhesive layer: removing the release film from the film material obtained in S3, coating the adhesive layer glue on the surface of the reinforcing layer by using a rotary coater or screen printing, and then baking at a temperature range of 50 to 100° C. for 1 to 50 minutes. After baking, the reinforcing layer remains soft and uncured, and a double-layer film is formed after compounding the release film; Step S5, removing the base film on the double-layer film reinforcement layer obtained in S4, repeating step S4, and forming a three-layer film with the composite release film; Step S6: alternately stack the double-layer film obtained in S4 or the multi-layer film obtained in S5 with a flat steel plate, and place them in a vacuum press at a pressure of 10-100 PSI and 50-100° C. for 4-8 hours.

10. A method for detecting a multilayer thermosetting film according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1, cutting the multilayer film into square pieces with a side length of 20 mm, a total of S pieces, where S can be 5-50; Step S2, the square sheets are laminated together, and a vacuum laminating machine is used to remove air bubbles and form a thick film, and the test thickness is A micrometers; Step S3: Place the thick film into a hot pressing device, evacuate, and place in an oven at 80°C-150°C for 1-5 minutes at a pressure of 1Kg / cm 2 ; Step S4, test S3, the thickness of the solidified material is B micrometers, and the fluidity is characterized by: L = (AB) / (S*A) * 100. If the L measured for the sample is 10-60, the sample is qualified.

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