Epoxy resin-based UV (ultraviolet) visbreaking film for semiconductor packaging and preparation method thereof

Abstract

The invention relates to the technical field of epoxy resin materials, and discloses an epoxy resin-based UV viscosity-reducing film for semiconductor packaging and a preparation method of the epoxy resin-based UV viscosity-reducing film. Comprising the following operation steps: step 1, adding a reactive diluent into acetone, uniformly mixing, adding a photoinitiator, uniformly mixing for 20-30 minutes, adding hexafluorobutyl acrylate, modified epoxy resin and epoxy acrylic resin, and uniformly mixing to obtain a UV visbreaking coating; and 2, carrying out corona treatment on the polyolefin film, coating the polyolefin film with a UV visbreaking coating, and drying to obtain the epoxy resin-based UV visbreaking film.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy resin materials, in particular to an epoxy resin-based UV viscosity-reducing film for semiconductor packaging and a preparation method thereof. Background Art

[0002] During the semiconductor packaging process, anti-sticking films are used to temporarily fix chips and other components, and subsequently need to be peeled off with no residual glue and low damage through specific methods. Traditional anti-sticking films mostly use ordinary resin systems, which do not provide sufficient protection for semiconductor chips. For example, the peeling force decreases after UV irradiation, and residual glue is easily generated. These problems cannot meet the stringent requirements of high-precision semiconductor packaging. In addition, semiconductor packaging works at high temperatures, so UV anti-sticking films need to have good heat resistance and no residual glue after UV curing.

[0003] In summary, it is of great significance to prepare an epoxy resin-based UV viscosity-reducing film for semiconductor packaging. Summary of the Invention

[0004] The object of the present invention is to provide an epoxy resin-based UV anti-viscosity film for semiconductor packaging and a preparation method thereof, so as to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: An epoxy resin-based UV viscosity-reducing film for semiconductor packaging and a preparation method thereof, comprising the following steps: Step 1: Add the active diluent to acetone and mix evenly, add the photoinitiator and mix evenly for 20 to 30 minutes, add hexafluorobutyl acrylate, modified epoxy resin, and epoxy acrylic resin and mix evenly to obtain a UV viscosity-reducing coating; Step 2: After corona treatment, the polyolefin film is coated with a UV anti-viscosity coating and dried to obtain an epoxy resin-based UV anti-viscosity film.

[0006] More optimally, the raw materials of the UV viscosity-reducing coating include the following components: by mass, 30 to 40 parts of epoxy acrylic resin, 15 to 20 parts of modified epoxy resin, 20 to 25 parts of active diluent, 3 to 4 parts of hexafluorobutyl acrylate, 6 to 7 parts of photoinitiator, and 12 to 17 parts of acetone.

[0007] A more optimized preparation method of the modified epoxy resin is as follows: 1,3,5-benzenetricarboxylic acid is added to acetone at 80-90°C and mixed evenly, a cycloaliphatic epoxy resin and a catalyst are added, stirred for 1.5-2 hours, acrylic acid, a catalyst, and a polymerization inhibitor are added and mixed evenly, stirred for 1-2 hours, heated to 100-105°C, the acid value is detected to be as low as 5 mg / KOH / g, and the temperature is reduced to 60-65°C before discharging to obtain the modified epoxy resin.

[0008] More optimally, the raw materials of the modified epoxy resin include the following components: by mass, 0.3-0.35 parts of 1,3,5-benzenetricarboxylic acid, 0.02-0.04 parts of catalyst, 0.001-0.002 parts of polymerization inhibitor, 0.9-1.5 parts of alicyclic epoxy resin, and 0.2-0.24 parts of acrylic acid.

[0009] The more optimized preparation method of the active diluent is as follows: (1) adding succinic acid to acetone and mixing uniformly, adding epoxidized soybean oil, epoxidized nano-alumina, and a catalyst at 90-100°C, stirring for 40-50 minutes, adding acrylic acid and an inhibitor, and continuing stirring for 1-1.2 hours, heating to 120-125°C, and stopping the reaction when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) adding active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether, and a photoinitiator to acetone and mixing uniformly, and irradiating under ultraviolet light for 1-2 hours to obtain an active diluent.

[0010] More optimally, the raw materials of active diluent A include the following components: by mass, 0.11-0.12 parts of succinic acid, 0.95-1.1 parts of epoxidized soybean oil, 0.1-0.13 parts of epoxidized nano-alumina, and 3-4 parts of acrylic acid.

[0011] More optimally, the molar ratio of the active diluent A, 1,4-benzenedithiol, and ethylene glycol divinyl ether is 1:1:1.

[0012] More optimally, the photoinitiator comprises a sulfonium salt and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:(0.5-0.7).

[0013] Compared with the prior art, the present invention has the following beneficial effects: The invention comprises the following steps: uniformly mixing active diluent, photoinitiator, hexafluorobutyl acrylate, modified epoxy resin and epoxy acrylic resin to prepare UV viscosity-reducing coating; corona-treating polyolefin film and then coating it with UV viscosity-reducing coating to obtain epoxy resin-based UV viscosity-reducing film.

[0014] In the scheme, the modified epoxy resin is a branched structure that can provide multiple acrylate functional groups, which cooperate with the epoxy group for dual curing, and form a three-dimensional cross-linked network through free radical polymerization under UV light, giving the UV anti-viscosity film heat resistance and rapid curing properties; the acrylate group in hexafluorobutyl acrylate participates in the copolymerization, and the hexafluoroisopropyl group forms a low surface energy layer after curing, which significantly reduces the adhesion and makes the UV anti-viscosity film easy to peel off from the substrate.

[0015] However, modified epoxy resins increase the viscosity of UV viscosity-reducing coatings, making them difficult to coat; and the compatibility between free radical photoinitiators and cationic photoinitiators is poor, affecting the dispersibility of each component; to solve this problem, the solution adds active diluents to improve the fluidity of UV viscosity-reducing coatings and the compatibility between free radical photoinitiators and cationic photoinitiators, thereby improving the photocuring efficiency.

[0016] In the scheme, epoxidized soybean oil, epoxidized nano-alumina, and succinic acid are reacted for a period of time, and then acrylic acid is added to obtain active diluent A; active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether, and a photoinitiator are added to acetone and evenly mixed, and irradiated under ultraviolet light for 1 to 2 hours to obtain the active diluent.

[0017] Among them, the active diluent has good heat resistance; it can cooperate with the modified epoxy resin to improve the heat resistance of the UV viscosity-reducing film, which is beneficial for its application in semiconductor packaging; In this scheme, the carboxyl groups on succinic acid react with the epoxy groups on epoxidized soybean oil and epoxidized nano-alumina, respectively. Then, the carboxyl groups on acrylic acid continue to react with the epoxy groups. The high reactivity of acrylates can increase the crosslinking point density. By adjusting the amount of acrylic acid added, the curing speed and material toughness can be balanced. In addition, the introduction of epoxy nano-alumina and 1,4-benzenedithiol can improve heat resistance. However, if the amount of epoxy nano-alumina added is too high, it will reduce UV transmittance and affect the UV viscosity reduction effect. Then, 1,4-benzenedithiol, reactive diluent A, and ethylene glycol divinyl ether were subjected to a click chemistry reaction at a molar ratio of 1:1:1 to form a thioether bond (-CSC-) to obtain a reactive diluent containing an acrylate group and a vinyl ether; Among them, the sulfide bond (-CSC-) and epoxidized soybean oil contain polar functional groups, which improve the surface performance and cohesion of the resin, and can further promote the compatibility between free radicals and cationic components; the sulfide bond can reduce the inhibitory effect of oxygen on free radical curing and improve the surface curing effect.

[0018] Acrylate groups participate in free radical polymerization; vinyl ether groups participate in cationic polymerization. The two are connected through the same molecular chain to form an interpenetrating network, which enhances the compatibility of the two phases. The chemical bonding of acrylate and vinyl ether (through thiol-ene click reaction) can avoid the phase separation problem in traditional physical blending and achieve homogeneous curing. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] In the following specific embodiments, parts are by mass. In this embodiment, it should be noted that the purchase manufacturers of all raw materials involved in the present invention are not particularly restricted. Examples thereof include: 1,3,5-benzenetricarboxylic acid with a CAS number of 554-95-0; the product number of the alicyclic epoxy resin is Syna Epoxy S-06E; the product number of the epoxy acrylate resin (bisphenol A epoxy acrylate) is QF5998; the CAS number of acrylic acid is 79-10-7; the CAS number of hexafluorobutyl acrylate is 54052-90-3; the CAS number of succinic acid is 110-15-6; the CAS number of epoxidized soybean oil is 8013-07-8; the CAS number of 1,4-benzenedithiol is 624-39-5; the CAS number of ethylene glycol divinyl ether is 764-99-8; and the CAS number of KH560 (γ-glycidyloxypropyltrimethoxysilane) is 2530-83-8.

[0021] In the scheme, the preparation method of epoxidized nano-alumina is as follows: KH560 is added to deionized water and mixed evenly, and the pH is adjusted to 4.5 with glacial acetic acid to obtain a KH560 hydrolyzate; the nano-alumina is ultrasonically dispersed in an ethanol aqueous solution (the mass ratio of ethanol to water is 1:1), the KH560 hydrolyzate is added, and the mixture is refluxed at 82°C for 4.5 hours, centrifuged, washed, dried, and ground to obtain epoxidized nano-alumina.

[0022] Example 1: A method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging, comprising the following steps: Step 1: (1) Add 0.4 parts of 1,3,5-benzenetricarboxylic acid to 90°C acetone and mix evenly, add 0.9 parts of alicyclic epoxy resin and 0.01 parts of catalyst, stir for 1 hour, add 0.2 parts of acrylic acid, 0.01 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 1.5 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 20 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 15 parts of modified epoxy resin, and 30 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed evenly, 0.98 parts of epoxidized soybean oil, 0.1 parts of epoxidized nano-alumina and 0.012 parts of a catalyst are added at 90°C, stirred for 50 minutes, 3 parts of acrylic acid and 0.002 parts of an inhibitor are added, stirring is continued for 1 hour, the temperature is raised to 120°C, and the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) active diluent A, 1,4-benzenedithiol and ethylene glycol divinyl ether are weighed in a molar ratio of 1:1:1; active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether and a photoinitiator (2,4,6-trimethylbenzoyldiphenylphosphine oxide) are added to acetone and mixed evenly, and irradiated under ultraviolet light for 2 hours to obtain an active diluent.

[0023] Example 2: A method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging, comprising the following steps: Step 1: (1) Add 0.4 parts of 1,3,5-benzenetricarboxylic acid to 90°C acetone and mix evenly, add 0.9 parts of alicyclic epoxy resin and 0.01 parts of catalyst, stir for 1 hour, add 0.2 parts of acrylic acid, 0.01 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 1.5 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 25 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 20 parts of modified epoxy resin, and 40 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating, heated and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed evenly, 0.98 parts of epoxidized soybean oil, 0.1 parts of epoxidized nano-alumina and 0.012 parts of a catalyst are added at 90°C, stirred for 50 minutes, 3 parts of acrylic acid and 0.002 parts of an inhibitor are added, stirring is continued for 1 hour, the temperature is raised to 120°C, and the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) active diluent A, 1,4-benzenedithiol and ethylene glycol divinyl ether are weighed in a molar ratio of 1:1:1; active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether and a photoinitiator (2,4,6-trimethylbenzoyldiphenylphosphine oxide) are added to acetone and mixed evenly, and irradiated under ultraviolet light for 2 hours to obtain an active diluent.

[0024] Example 3: A method for preparing an epoxy resin-based UV anti-viscosity film for semiconductor packaging, comprising the following steps: Step 1: (1) Add 0.4 parts of 1,3,5-benzenetricarboxylic acid to 90°C acetone and mix evenly, add 0.9 parts of alicyclic epoxy resin and 0.01 parts of catalyst, stir for 1 hour, add 0.2 parts of acrylic acid, 0.01 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 1.5 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 25 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 15 parts of modified epoxy resin, and 40 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed evenly, 0.98 parts of epoxidized soybean oil, 0.1 parts of epoxidized nano-alumina and 0.012 parts of a catalyst are added at 90°C, stirred for 50 minutes, 3 parts of acrylic acid and 0.002 parts of an inhibitor are added, stirring is continued for 1 hour, the temperature is raised to 120°C, and the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) active diluent A, 1,4-benzenedithiol and ethylene glycol divinyl ether are weighed in a molar ratio of 1:1:1; active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether and a photoinitiator (2,4,6-trimethylbenzoyldiphenylphosphine oxide) are added to acetone and mixed evenly, and irradiated under ultraviolet light for 2 hours to obtain an active diluent.

[0025] Comparative Example 1 is based on Example 2, but the modified epoxy resin is not branched; Step 1: (1) Add 0.9 parts of alicyclic epoxy resin to acetone and mix evenly, heat to 90°C, add 0.2 parts of acrylic acid, 0.02 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 2 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 25 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 20 parts of modified epoxy resin, and 40 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating, heated and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed evenly, 0.98 parts of epoxidized soybean oil, 0.1 parts of epoxidized nano-alumina and 0.012 parts of a catalyst are added at 90°C, stirred for 50 minutes, 3 parts of acrylic acid and 0.002 parts of an inhibitor are added and stirred for 1 hour, the temperature is raised to 120°C, and the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain an active diluent A; (2) active diluent A, 1,4-benzenedithiol and ethylene glycol divinyl ether are weighed in a molar ratio of 1:1:1; active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether and a photoinitiator are added to acetone and mixed evenly, and irradiated under ultraviolet light for 2 hours to obtain an active diluent.

[0026] Comparative Example 2 is based on Example 2, but the amount of epoxy nano-alumina added is increased; Step 1: (1) Add 0.4 parts of 1,3,5-benzenetricarboxylic acid to 90°C acetone and mix evenly, add 0.9 parts of alicyclic epoxy resin and 0.01 parts of catalyst, stir for 1 hour, add 0.2 parts of acrylic acid, 0.01 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 1.5 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 25 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 20 parts of modified epoxy resin, and 40 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating, heated and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed evenly, 0.98 parts of epoxidized soybean oil, 1.5 parts of epoxidized nano-alumina and 0.012 parts of a catalyst are added at 90°C, stirred for 50 minutes, 3 parts of acrylic acid and 0.002 parts of an inhibitor are added, stirring is continued for 1 hour, the temperature is raised to 120°C, and the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain an active diluent A; (2) active diluent A, 1,4-benzenedithiol and ethylene glycol divinyl ether are weighed in a molar ratio of 1:1:1; active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether and a photoinitiator (2,4,6-trimethylbenzoyldiphenylphosphine oxide) are added to acetone and mixed evenly, and irradiated under ultraviolet light for 2 hours to obtain an active diluent.

[0027] Comparative Example 3 was based on Example 2, except that ethylene glycol divinyl ether was not added; Step 1: (1) Add 0.4 parts of 1,3,5-benzenetricarboxylic acid to 90°C acetone and mix evenly, add 0.9 parts of alicyclic epoxy resin and 0.01 parts of catalyst, stir for 1 hour, add 0.2 parts of acrylic acid, 0.01 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 1.5 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 25 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 20 parts of modified epoxy resin, and 40 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating, heated and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed evenly, 0.98 parts of epoxidized soybean oil, 0.1 parts of epoxidized nano-alumina and 0.012 parts of catalyst are added at 90°C, stirred for 50 minutes, 3 parts of acrylic acid and 0.002 parts of polymerization inhibitor are added, stirring is continued for 1 hour, the temperature is raised to 120°C, and the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) active diluent A and 1,4-benzenedithiol are weighed in a molar ratio of 2:1; active diluent A, 1,4-benzenedithiol and a photoinitiator (2,4,6-trimethylbenzoyldiphenylphosphine oxide) are added to acetone and mixed evenly, and irradiated under ultraviolet light for 2 hours to obtain active diluent.

[0028] Comparative Example 4 Based on Example 2, ethylene glycol divinyl ether and reactive diluent A were mixed to obtain a reactive diluent; Step 1: (1) Add 0.4 parts of 1,3,5-benzenetricarboxylic acid to 90°C acetone and mix evenly, add 0.9 parts of alicyclic epoxy resin and 0.01 parts of catalyst, stir for 1 hour, add 0.2 parts of acrylic acid, 0.01 parts of catalyst, and 0.001 parts of polymerization inhibitor and mix evenly, stir for 1.5 hours, heat to 100°C, detect the acid value as low as 5 mg / KOH / g, reduce to 60°C and discharge to obtain modified epoxy resin; (2) Add 25 parts of active diluent to 17 parts of acetone and mix evenly, add 6 parts of photoinitiator and mix evenly for 30 minutes, add 3 parts of hexafluorobutyl acrylate, 20 parts of modified epoxy resin, and 40 parts of epoxy acrylic resin and mix evenly to obtain UV viscosity-reducing coating; wherein the photoinitiator includes sulfonium salt (Uyracure-160) and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:0.6; Step 2: After corona treatment, the polyolefin film is coated with a UV viscosity-reducing coating, heated and dried to obtain an epoxy resin-based UV viscosity-reducing film; The preparation method of the active diluent is as follows: (1) 0.12 parts of succinic acid are added to acetone and mixed uniformly; 0.98 parts of epoxidized soybean oil, 0.1 parts of epoxidized nano-alumina and 0.012 parts of a catalyst are added at 90°C and stirred for 50 minutes; 3 parts of acrylic acid and 0.002 parts of an inhibitor are added and stirred for 1 hour; the temperature is raised to 120°C; the reaction is stopped when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) active diluent A is uniformly mixed with ethylene glycol divinyl ether to obtain an active diluent.

[0029] Testing: The UV anti-viscosity films prepared in Examples 1-3 and Comparative Examples 1-4 were cut into pieces 25 mm wide and 150 mm long, respectively, and attached to stainless steel plates (SUS) and pressed six times using a 2 kg roller. The films were then treated at 120°C for one hour and naturally cooled. The 180° peel strength of Examples 1-3 and Comparative Examples 1-4 was then tested in accordance with GB / T 2792-2014, as well as the 180° peel strength after 20 minutes of UV irradiation (high-pressure mercury lamp). Table 1 180° peel strength (N / 25mm) 180° peel strength after UV irradiation (N / 25mm) Residual adhesive after UV Example 1 23.4 0.13 No residual glue Example 2 25.8 0.10 No residual glue Example 3 24.7 0.15 No residual glue Comparative Example 1 14.2 0.22 A small amount of residual glue Comparative Example 2 21.3 0.36 A lot of residual glue Comparative Example 3 16.4 0.14 No residual glue Comparative Example 4 18.3 0.17 No residual glue Conclusion: Comparative Example 1 is based on Example 2, and the modified epoxy resin is not branched, which results in a decrease in heat resistance and thus a decrease in the performance of the UV anti-viscosity film; Comparative Example 2 is based on Example 2, and increasing the amount of epoxy nano-alumina added will reduce the UV transmittance, thereby reducing the UV anti-viscosity effect and resulting in residual glue after UV curing; Comparative Example 3 is based on Example 2, and ethylene glycol divinyl ether is not added; resulting in a decrease in the compatibility and activity of the photoinitiator, thereby resulting in a decrease in performance; Comparative Example 4 is based on Example 2, and ethylene glycol divinyl ether is mixed with active diluent A to obtain an active diluent; resulting in a decrease in the performance of the UV anti-viscosity film; because the chemical bonding of acrylate and vinyl ether (through thiol-ene click reaction) can avoid the phase separation problem during traditional physical blending, homogeneous curing can be achieved.

[0030] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging, characterized in that: The following steps are included: Step 1: Add the active diluent to acetone and mix evenly, add the photoinitiator and mix evenly for 20 to 30 minutes, add hexafluorobutyl acrylate, modified epoxy resin, and epoxy acrylic resin and mix evenly to obtain a UV viscosity-reducing coating; Step 2: After corona treatment, the polyolefin film is coated with a UV anti-viscosity coating and dried to obtain an epoxy resin-based UV anti-viscosity film.

2. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 1, wherein: The raw materials of the UV viscosity-reducing coating include the following components: 30-40 parts of epoxy acrylic resin, 15-20 parts of modified epoxy resin, 20-25 parts of active diluent, 3-4 parts of hexafluorobutyl acrylate, 6-7 parts of photoinitiator, and 12-17 parts of acetone, calculated by mass.

3. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 1, wherein: The preparation method of the modified epoxy resin comprises the following steps: adding 1,3,5-benzenetricarboxylic acid to acetone at 80-90° C. and uniformly mixing; adding an alicyclic epoxy resin and a catalyst and stirring for 1.5-2 hours; adding acrylic acid, a catalyst and a polymerization inhibitor and uniformly mixing; stirring for 1-2 hours; heating to 100-105° C., detecting an acid value as low as 5 mg / KOH / g, and cooling the temperature to 60-65° C. to discharge the material, thereby obtaining the modified epoxy resin.

4. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 3, wherein: The raw materials of the modified epoxy resin include the following components: 0.3-0.35 parts of 1,3,5-benzenetricarboxylic acid, 0.02-0.04 parts of a catalyst, 0.001-0.002 parts of a polymerization inhibitor, 0.9-1.5 parts of alicyclic epoxy resin, and 0.2-0.24 parts of acrylic acid, calculated by mass.

5. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 1, wherein: The preparation method of the active diluent is as follows: (1) adding succinic acid to acetone and uniformly mixing, adding epoxidized soybean oil, epoxidized nano-alumina and a catalyst at 90-100° C. and stirring for 40-50 minutes, adding acrylic acid and an inhibitor and continuing stirring for 1-1.2 hours, raising the temperature to 120-125° C., and stopping the reaction when the acid value is less than 20 mgKOH / g to obtain active diluent A; (2) adding active diluent A, 1,4-benzenedithiol, ethylene glycol divinyl ether and a photoinitiator to acetone and uniformly mixing, and irradiating under ultraviolet light for 1-2 hours to obtain the active diluent.

6. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 5, wherein: The raw materials of the active diluent A include the following components: 0.11-0.12 parts of succinic acid, 0.95-1.1 parts of epoxidized soybean oil, 0.1-0.13 parts of epoxidized nano-alumina, and 3-4 parts of acrylic acid, calculated by mass.

7. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 5, wherein: The molar ratio of the active diluent A, 1,4-benzenedithiol and ethylene glycol divinyl ether is 1:1:

1.

8. The method for preparing an epoxy resin-based UV viscosity-reducing film for semiconductor packaging according to claim 1, wherein: The photoinitiator comprises a sulfonium salt and 2,4,6-trimethylbenzoyldiphenylphosphine oxide in a mass ratio of 1:(0.5-0.7).