N-substituted maleimide terpolymer resin, temporary bonding adhesive and adhesive film

Abstract

The invention discloses N-substituted maleimide terpolymer resin. The N-substituted maleimide terpolymer resin comprises an N-substituted maleimide unit, a first alkene monomer unit and a second alkene monomer unit, wherein the structures of the first alkene monomer unit and the second alkene monomer unit are different. According to the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin disclosed by the invention, a hardened material also has relatively high bonding force with a chip at a high temperature, so that the chip can be prevented from shifting under high-temperature conditions such as plastic packaging and the like. Meanwhile, the compatibility of the N-substituted maleimide terpolymer resin and the non-polar resin is good, and the storage stability of the temporary bonding adhesive can be improved when the temporary bonding adhesive further comprises the non-polar resin component.

Description

Technical Field

[0001] The present application relates to the technical field of temporary bonding adhesives, and in particular to an N-substituted maleimide terpolymer resin, a temporary bonding adhesive, and an adhesive film. Background Art

[0002] In recent years, with the rise of new technologies such as 5G, cloud computing, and artificial intelligence, the integrated circuit packaging industry has developed rapidly. As the number of chip I / Os increases, fan-out packaging was born when the chip size could not accommodate all the I / Os. In fan-out packaging, there are two main process flows, namely chip first and RDL first. In the chip first process, the cut chip is first placed on the set position of a temporary carrier with temporary bonding adhesive by a high-precision placement machine, and then the molding, RDL production, ball planting, debonding, and dicing processes are carried out. In the molding process, since the molding compound is processed under high temperature and high pressure, it will have an impact on the chip mounted on the carrier, causing the chip to have a certain positional offset. In addition, during the post-curing process of the molding compound, due to volume shrinkage, the chip will cause secondary offset, seriously affecting the normal progress of the subsequent packaging process and resulting in yield loss.

[0003] Currently, there are two main methods for reducing chip position shift. The first is through improved packaging processes. For example, a groove structure is created in the temporary bonding film, and the chip is affixed to the groove structure of the film layer. The groove structure is used to limit the chip position during plastic encapsulation, thereby reducing chip shift. The second method is to directly improve the bonding strength between the chip and the temporary bonding adhesive. This eliminates the need for additional processes and not only effectively solves the chip shift problem, but also improves overall efficiency and reduces costs. Summary of the Invention

[0004] In view of this, the present application provides an N-substituted maleimide terpolymer resin, a temporary bonding adhesive and an adhesive film, aiming to improve the problem of unsatisfactory bonding strength between the temporary bonding film and the chip after curing or unsatisfactory film forming properties or storage stability of the temporary bonding film having N-substituted maleimide resin.

[0005] In a first aspect, an embodiment of the present application provides an N-substituted maleimide terpolymer resin, comprising an N-substituted maleimide unit, a first olefin monomer unit, and a second olefin monomer unit; wherein the first olefin monomer unit and the second olefin monomer unit have different structures.

[0006] Beneficial effects:

[0007] Because the N-substituted maleimide terpolymer resin in the present application contains an imide ring structure, the resin cured product in the present application has a higher glass transition temperature. When the N-substituted maleimide terpolymer resin in the present application is used in a temporary bonding adhesive, the glass transition temperature of the material after the temporary bonding adhesive is hardened can be increased, and then the temporary bonding adhesive with the N-substituted maleimide terpolymer resin in the present application, the material after hardening also has a higher bonding force with the chip at high temperature, thereby being able to avoid the chip from shifting under high temperature conditions such as plastic sealing. At the same time, due to the large rigidity of the imide ring structure, resulting in large molecular stress, the N-substituted maleimide terpolymer resin also includes a first olefin monomer unit and a second olefin monomer unit, which is conducive to reducing the molecular chain rigidity of the terpolymer and avoiding the problem of unsatisfactory film-forming effect due to large internal stress. At the same time, the N-substituted maleimide terpolymer resin includes N-substituted maleimide units, a first olefin monomer unit, and a second olefin monomer unit, which is beneficial to reducing the polarity of the N-substituted maleimide resin, and is beneficial to improving the compatibility of the N-substituted maleimide terpolymer resin with the non-polar resin. When the temporary bonding adhesive also includes a non-polar resin component, it is beneficial to improve the storage stability of the temporary bonding adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1 Graph showing the storage modulus of the temporary bonding adhesive film at different temperatures in some embodiments of the present application.

[0010] Figure 2 Schematic diagram of the bonding strength test of temporary bonding adhesive.

[0011] Figure 3 A schematic diagram of the packaging structure provided in an embodiment of the present application.

[0012] Figure 4 for Figure 3 Schematic diagram of the packaging structure from another perspective.

[0013] Figure 5 This is a SAM photo of the packaging structure of Example 1 of the present application.

[0014] Figure Number:

[0015] 1-support platform, 2-glass carrier, 3-release layer, 4-adhesive film, 5-chip, 6-test pusher, 7-plastic sealing layer. DETAILED DESCRIPTION

[0016] The experimental examples described in this application are only some of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain this application and are not intended to limit this application.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0018] In the description of this application, the term "including" means "including but not limited to." The terms first, second, third, etc. are used merely as labels and do not impose numerical requirements or establish a sequence.

[0019] In this application, "and / or" describes the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0020] In this application, "at least one" means one or more, and "plurality" means two or more. "One or more", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or plural, respectively.

[0021] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a hard limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numbers within the range. For example, the description of a range from 1 to 6 should be considered to have specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which applies regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0022] In recent years, with the rise of new technologies such as 5G, cloud computing, and artificial intelligence, the integrated circuit packaging industry has developed rapidly. As the number of chip I / Os increases, fan-out packaging was born when the chip size could not accommodate all the I / Os. In fan-out packaging, there are two main process flows, namely chip first and RDL first. In the chip first process, the cut chip is first placed on the set position of a temporary carrier with temporary bonding adhesive by a high-precision placement machine, and then the molding, RDL production, ball planting, debonding, and dicing processes are carried out. In the molding process, since the molding compound is processed under high temperature and high pressure, it will have an impact on the chip mounted on the carrier, causing the chip to have a certain positional offset. In addition, during the post-curing process of the molding compound, due to volume shrinkage, the chip will cause secondary offset, seriously affecting the normal progress of the subsequent packaging process and resulting in yield loss.

[0023] Currently, there are two main methods for reducing chip position shift. The first is through improved packaging processes. For example, a groove structure is created in the temporary bonding film, and the chip is affixed to the groove structure of the film layer. The groove structure is used to limit the chip position during plastic encapsulation, thereby reducing chip shift. The second method is to directly improve the bonding strength between the chip and the temporary bonding adhesive. This eliminates the need for additional processes and not only effectively solves the chip shift problem, but also improves overall efficiency and reduces costs.

[0024] In view of this, an embodiment of the present application provides an N-substituted maleimide terpolymer resin, comprising an N-substituted maleimide unit, a first olefin monomer unit, and a second olefin monomer unit; wherein the first olefin monomer unit and the second olefin monomer unit have different structures.

[0025] It should be noted that the N-substituted maleimide units herein refer to structural units formed by polymerization of N-substituted maleimide monomers. Similarly, the first olefin monomer units refer to structural units formed by polymerization of the first olefin monomer. The second olefin monomer units refer to structural units formed by polymerization of the second olefin monomer. The N-substituted maleimide terpolymer resin herein can also be understood as a product prepared by copolymerization of an N-substituted maleimide monomer, a first olefin monomer, and a second olefin monomer.

[0026] It is understandable that, because the N-substituted maleimide terpolymer resin in the present application contains an imide ring structure, the resin cured product in the present application has a higher glass transition temperature. When the N-substituted maleimide terpolymer resin in the present application is used in a temporary bonding adhesive, the glass transition temperature of the material after the temporary bonding adhesive is hardened can be increased, and then the temporary bonding adhesive with the N-substituted maleimide terpolymer resin in the present application, the material after hardening also has a higher bonding force with the chip at high temperatures, thereby being able to avoid the offset of the chip under high temperature conditions such as plastic packaging. Simultaneously, due to the larger rigidity of the imide ring structure, it is easy to cause molecular stress to be larger. The N-substituted maleimide terpolymer resin also includes a first olefin monomer unit and a second olefin monomer unit, which is conducive to reducing the molecular chain rigidity of the terpolymer, avoiding the problem that the film forming effect is undesirable due to the larger internal stress. At the same time, the N-substituted maleimide terpolymer resin includes N-substituted maleimide units, a first olefin monomer unit, and a second olefin monomer unit, which is beneficial to reducing the polarity of the N-substituted maleimide resin, and is beneficial to improving the compatibility of the N-substituted maleimide terpolymer resin with the non-polar resin. When the temporary bonding adhesive also includes a non-polar resin component, it is beneficial to improve the storage stability of the temporary bonding adhesive.

[0027] In some embodiments of the present application, the N-substituted maleimide monomer is a compound having a structure shown in the following formula (1);

[0028]

[0029] The substituent R1 includes one of a straight-chain alkyl group or a substituent thereof, a branched-chain alkyl group or a substituent thereof, a cycloalkyl group or a substituent thereof, and an aryl group or a substituent thereof. Further, R1 includes one of a straight-chain alkyl group having 1 to 6 carbon atoms or a substituent thereof, a branched-chain alkyl group having 3 to 6 carbon atoms or a substituent thereof, a cycloalkyl group having 3 to 12 carbon atoms or a substituent thereof, and an aryl group having 6 to 20 carbon atoms or a substituent thereof.

[0030] Illustratively, R1 includes, but is not limited to, one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, chloromethyl, dichloromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, benzyl, methylphenyl, dimethylphenyl, trimethylphenyl, naphthyl, and anthracenyl.

[0031] Illustratively, the N-substituted maleimide monomer is one of N-methylmaleimide, N-ethylmaleimide, N-tert-butylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide. This helps further improve the high-temperature bonding performance of the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin.

[0032] In some embodiments of the present application, the first olefin monomer is one of α-olefin and its substituents, cyclic olefin and its substituents, bridged cyclic olefin and its substituents.

[0033] For example, the first olefin monomer is butene, isobutylene, butadiene, pentene, vinyl chloride, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, 1-methylcyclopentene, 1-methylcyclohexene, bicyclo[2,2,1]hept-2-ene, 1-methylbicyclo[2,2,1]hept-2-ene, 5-methylbicyclo[2,2,1]hept-2 -ene, 7-methylbicyclo[2,2,1]hept-2-ene, 1-ethylbicyclo[2,2,1]hept-2-ene, 5-ethylbicyclo[2,2,1]hept-2-ene, 1-propylbicyclo[2,2,1]hept-2-ene, 5-propylbicyclo[2,2,1]hept-2-ene, 1-butylbicyclo[2,2,1]hept-2-ene, 5-butylbicyclo[2,2,1]hept-2-ene.

[0034] Furthermore, the first olefin monomer is one of butadiene, styrene, cyclohexene, 1-methylcyclohexene, bicyclo[2,2,1]hept-2-ene, 5-methylbicyclo[2,2,1]hept-2-ene, 5-ethylbicyclo[2,2,1]hept-2-ene, 5-propylbicyclo[2,2,1]hept-2-ene, and 5-butylbicyclo[2,2,1]hept-2-ene.

[0035] In some embodiments of the present application, the second olefinic monomer is one of α-olefins and their substituents, cycloolefins and their substituents, and bridged cyclic olefins and their substituents. The first olefinic monomer and the second olefinic monomer only need to be different. It should be noted that the first olefinic monomer or the second olefinic monomer being a cycloolefin or a bridged cyclic olefin can improve the compatibility of the N-substituted maleimide terpolymer resin with the non-polar resin, and can also improve the heat resistance and bonding strength of the N-substituted maleimide terpolymer resin, further improving the high-temperature bonding performance of the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin.

[0036] For example, the second olefin monomer is butene, isobutylene, butadiene, pentene, vinyl chloride, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, 1-methylcyclopentene, 1-methylcyclohexene, bicyclo[2,2,1]hept-2-ene, 1-methylbicyclo[2,2,1]hept-2-ene, 5-methylbicyclo[2,2,1]hept-2 -ene, 7-methylbicyclo[2,2,1]hept-2-ene, 1-ethylbicyclo[2,2,1]hept-2-ene, 5-ethylbicyclo[2,2,1]hept-2-ene, 1-propylbicyclo[2,2,1]hept-2-ene, 5-propylbicyclo[2,2,1]hept-2-ene, 1-butylbicyclo[2,2,1]hept-2-ene, 5-butylbicyclo[2,2,1]hept-2-ene.

[0037] In some embodiments of the present application, the molar amount of the N-substituted maleimide unit in the N-substituted maleimide terpolymer resin is A, the molar number of the first olefin monomer unit in the N-substituted maleimide terpolymer resin is B, and the molar number of the second olefin monomer unit in the N-substituted maleimide terpolymer resin is C, then A:B:C is 1:(0.1-10):(0.1-10). It should be noted that if the value of B or C is too small, the obtained N-substituted maleimide terpolymer resin may easily cause phase separation when mixed with a non-polar resin or stored; if the value of B or C is too large, the obtained N-substituted maleimide terpolymer resin may easily cause unsatisfactory glass transition temperature and high temperature bonding performance, which is not conducive to improving the bonding strength between the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin and the chip at high temperature.

[0038] In some embodiments of the present application, the molar percentage of N-substituted maleimide units in the N-substituted maleimide terpolymer resin is 15% to 75%, that is, the ratio of A to the sum of (A+B+C) is 15% to 75%. It should be noted that if the molar percentage of N-substituted maleimide units in the N-substituted maleimide terpolymer resin is too low, the bonding strength between the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin and the chip will not be improved to an ideal extent; if the molar percentage of N-substituted maleimide units is too high, it is easy to lead to unsatisfactory compatibility between the N-substituted maleimide terpolymer resin and the elastomer resin, and it may also cause the prepared adhesive film to fail to soften during chip bonding, affecting the bonding process.

[0039] For example, the molar percentage of N-substituted maleimide units in the N-substituted maleimide terpolymer resin is 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 110%, 111%, 112%, 113%, 114%, 115%, 116%, 117%, 118%, 119%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75% and values between any two of the above values.

[0040] Furthermore, the molar percentage of N-substituted maleimide units in the N-substituted maleimide terpolymer resin is 20% to 55%.

[0041] In some embodiments of the present application, the molar percentage of the first olefinic monomer unit or the second olefinic monomer unit in the N-substituted maleimide terpolymer resin is 5% to 75%, preferably 5% to 55%. This helps improve the compatibility of the N-substituted maleimide terpolymer resin with the elastomer resin and ensures a higher bonding strength between the prepared temporary bonding adhesive and the chip.

[0042] In some embodiments of the present application, the number average molecular weight of the N-substituted maleimide terpolymer resin is 3000 g / mol to 7000 g / mol. It should be noted that if the number average molecular weight of the N-substituted maleimide terpolymer resin is too low, the bonding strength between the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin and the chip will not be improved to an ideal extent; if the number average molecular weight of the N-substituted maleimide terpolymer resin is too high, it will easily lead to unsatisfactory compatibility between the N-substituted maleimide terpolymer resin and the elastomer resin, and may also cause the prepared adhesive film to fail to soften during patching, affecting the patching.

[0043] For example, the number average molecular weight of the N-substituted maleimide terpolymer resin is 3000 g / mol, 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol, and values between any two of the above values.

[0044] In some embodiments of the present application, the N-substituted maleimide terpolymer resin includes N-phenylmaleimide-butadiene-styrene copolymer, N-phenylmaleimide-hexene-styrene copolymer, N-phenylmaleimide-cyclohexene-styrene copolymer, N-phenylmaleimide-maleic anhydride-styrene copolymer, N-phenylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, N-phenylmaleimide-5-methylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-phenylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-phenylmaleimide-cyclohexene-bicyclo [2,2,1]hept-2-ene copolymer, N-phenylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-phenylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-phenylmaleimide-cyclopentene-cyclohexene copolymer, N-phenylmaleimide-cyclohexene-cycloheptene copolymer, N-phenylmaleimide-cyclohexene-cyclooctene copolymer, N-phenylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-phenylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-phenylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer butylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-butadiene-styrene copolymer, N-methylmaleimide-hexene-styrene copolymer, N-methylmaleimide-cyclohexene-styrene copolymer, N-methylmaleimide-maleic anhydride-styrene copolymer, N-methylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, N-methylmaleimide-5-methylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-methylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-methylmaleimide-cyclohexene-bicyclo[2,2,1]hept- 2-ene copolymer, N-methylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclopentene-cyclohexene copolymer, N-methylmaleimide-cyclohexene-cycloheptene copolymer, N-methylmaleimide-cyclohexene-cyclooctene copolymer, N-methylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-butadiene-styrene copolymer, N-cyclohexylmaleimide-hexene-styrene copolymer, N-cyclohexylmaleimide-cyclohexene-styrene copolymer, N-cyclohexylmaleimide-maleic anhydride-styrene copolymer, N-cyclohexylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, N-cyclohexylmaleimide-5-methylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-cyclohexylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-cyclohexylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide At least one of N-cyclohexylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-cyclopentene-cyclohexene copolymer, N-cyclohexylmaleimide-cyclohexene-cycloheptene copolymer, N-cyclohexylmaleimide-cyclohexene-cyclooctene copolymer, N-cyclohexylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, and N-cyclohexylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer.

[0045] Further, the N-substituted maleimide terpolymer resin includes N-phenylmaleimide-cyclohexene-styrene copolymer, N-phenylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, N-phenylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-phenylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-phenylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-bicyclo[ At least one of a cyclohexene-bicyclo[2,2,1]hept-2-ene-styrene copolymer, a cyclohexene-bicyclo[2,2,1]hept-2-ene-styrene copolymer, a cyclohexylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, a cyclohexylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, and a cyclohexylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer.

[0046] The present invention also provides a method for preparing an N-substituted maleimide terpolymer resin, comprising the following steps:

[0047] S110 provides an N-substituted maleimide monomer, a first olefin monomer, and a second olefin monomer; wherein the first olefin monomer is different from the second olefin monomer. It should be noted that the N-substituted maleimide monomer, the first olefin monomer, and the second olefin monomer have been described in detail above and are not further described here.

[0048] S120 is to copolymerize the N-substituted maleimide monomer, the first olefinic monomer, and the second olefinic monomer for a certain period of time to obtain a copolymerization reaction liquid having an N-substituted maleimide terpolymer resin.

[0049] S130 terminates the reaction and separates the N-substituted maleimide terpolymer resin from the copolymerization reaction solution.

[0050] In some embodiments of the present application, step S10 includes: adding an N-substituted maleimide monomer, a first olefinic monomer, and a second olefinic monomer to a first solvent and mixing them uniformly to obtain a liquid to be reacted. The first solvent can be a solvent that can effectively dissolve the monomers and the N-substituted maleimide terpolymer resin, and is not limited here. For example, the first solvent can be one of benzene, toluene, xylene, trimethylolbenzene, tetrahydrofuran, dioxane, dioxane, dichloroethane, and cyclohexane. Specifically, the solvent is dried and dehydrated using a drying device before use.

[0051] Furthermore, the mass ratio of the first solvent to the total amount of monomers is (50:1) to (1:1). That is, the mass ratio of the first solvent to the sum of the mass of the N-substituted maleimide monomer, the first olefinic monomer, and the second olefinic monomer is (50:1) to (1:1).

[0052] In some embodiments of the present application, step S20 includes: heating the mixture of the N-substituted maleimide monomer, the first olefin monomer and the second olefin monomer to 45° C. to 95° C., and then adding an initiator to cause the N-substituted maleimide monomer, the first olefin monomer and the second olefin monomer to copolymerize.

[0053] In some embodiments of the present application, the initiator is a free radical polymerization initiator. For example, the initiator is one of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, dodecanoyl peroxide, tert-butyl peroxyvalerate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, cumene hydroperoxide, tert-butyl hydroperoxide, diisopropyl peroxide, and di-tert-butyl peroxide. Further, the initiator is one of azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, and dodecanoyl peroxide.

[0054] Illustratively, the molar ratio of the initiator to the sum of the three monomers is (1:1000) to (1:10).

[0055] Exemplarily, the reaction time is 2 h to 6 h.

[0056] In some embodiments of the present application, step S30 includes: adding an alcohol solvent to the copolymerization reaction solution to terminate the reaction and precipitate the polymer, then repeatedly washing the polymer with the alcohol solvent until the residual monomer is washed away, and finally placing the polymer in a vacuum oven to dry to constant weight.

[0057] In some embodiments of the present application, the alcohol solvent includes a monohydric alcohol or dihydric alcohol having 1 to 5 carbon atoms. For example, the alcohol solvent includes at least one of methanol, ethanol, butanol, ethylene glycol, propylene glycol, isopropanol, and isobutanol. Furthermore, the solvent is at least one of methanol, ethanol, isopropanol, and isobutanol.

[0058] An embodiment of the present application further provides a temporary bonding adhesive, which includes the above-mentioned N-substituted maleimide terpolymer resin.

[0059] It is understood that because the N-substituted maleimide terpolymer resin in this application contains an imide ring structure, it can increase the glass transition temperature of the material after the temporary bonding adhesive in this application is hardened. As a result, the temporary bonding adhesive containing the N-substituted maleimide terpolymer resin in this application, after hardening, also has a high bonding strength with the chip at high temperatures, thereby preventing the chip from shifting under high-temperature conditions such as plastic packaging. At the same time, because the high rigidity of the imide ring structure can easily lead to high molecular stress, the N-substituted maleimide terpolymer resin also includes a first olefinic monomer unit and a second olefinic monomer unit, which helps reduce the molecular chain rigidity of the terpolymer and avoid the problem of unsatisfactory film formation due to high internal stress. At the same time, the N-substituted maleimide terpolymer resin includes N-substituted maleimide units, a first olefin monomer unit, and a second olefin monomer unit, which is beneficial to reducing the polarity of the N-substituted maleimide resin, and is beneficial to improving the compatibility of the N-substituted maleimide terpolymer resin with the non-polar resin. When the temporary bonding adhesive also includes a non-polar resin component, it is beneficial to improve the storage stability of the temporary bonding adhesive.

[0060] In some embodiments of the present application, the temporary bonding adhesive also includes an elastomeric resin. It should be noted that, although the internal stress of the terpolymer resin obtained by copolymerizing the first olefinic monomer and the second olefinic monomer with N-substituted maleimide in the present application is improved to a certain extent compared with the N-substituted maleimide resin, the film-forming property of the temporary bonding adhesive comprising the N-substituted maleimide terpolymer resin in the present application is still not ideal. In this embodiment, by further increasing the elastomeric resin in the temporary bonding adhesive, the film-forming property of the temporary bonding adhesive can be significantly improved. At the same time, the terpolymer resin obtained by copolymerizing the first olefinic monomer and the second olefinic monomer with N-substituted maleimide is compared with the N-substituted maleimide binary copolymer resin, and the terpolymer resin obtained by copolymerizing N-substituted maleimide has better compatibility with the elastomeric resin, which is conducive to avoiding phase separation when the components in the temporary bonding adhesive are blended or stored, and further improves the storage stability of the temporary bonding adhesive.

[0061] In some embodiments of the present application, the elastomer resin may be a styrene thermoplastic elastomer resin. Furthermore, the styrene thermoplastic elastomer resin includes a polymer resin having a styrene end-capped structure. Exemplarily, the styrene thermoplastic elastomer resin includes at least one of a single-end-capped styrene polymer resin and a double-end-capped styrene polymer resin.

[0062] In some embodiments of the present application, the elastomer resin includes at least one of a styrene-terminated polymer resin, a polyolefin elastomer resin, and a polyurethane elastomer resin. This allows the temporary bonding adhesive to exhibit excellent processability, film-forming properties, and storage stability. Furthermore, the cured temporary bonding adhesive exhibits good adhesion to the chip even at high temperatures.

[0063] In some embodiments of the present application, the temporary bonding adhesive includes the aforementioned N-substituted maleimide terpolymer resin and a styrene thermoplastic elastomer resin. It should be noted that the inventors have discovered that the compatibility of the binary copolymer resin obtained by copolymerizing N-substituted maleimide with an olefinic monomer with the styrene thermoplastic elastomer resin is not very ideal. When the temporary bonding adhesive includes both the N-substituted maleimide binary copolymer resin and the styrene thermoplastic elastomer resin, although the hardened temporary bonding adhesive still has a high bonding strength with the chip at high temperatures, the N-substituted maleimide binary copolymer resin and the styrene thermoplastic elastomer resin are prone to phase separation when the solution is blended, resulting in the prepared temporary bonding adhesive being unstable and unable to be stored for a long time. The inventors surprisingly discovered that using the N-substituted maleimide terpolymer resin provided in the embodiments of the present application to replace the N-substituted maleimide binary copolymer resin can effectively improve the problem of insufficient stability of the temporary bonding adhesive prepared from the N-substituted maleimide binary copolymer resin and the styrene thermoplastic elastomer resin, thereby helping to improve the storage stability of the temporary bonding adhesive.

[0064] In some embodiments of the present application, the temporary bonding adhesive includes an N-substituted maleimide terpolymer resin and an elastomer resin, and the ratio of the N-substituted maleimide terpolymer resin to the elastomer resin is (3-20): (5-35) by mass. It should be noted that if the ratio of the N-substituted maleimide terpolymer resin to the elastomer resin is too low, the improvement in the binding force (also known as the adhesion force) of the temporary bonding adhesive at high temperature in the present application is not ideal; if the ratio of the N-substituted maleimide terpolymer resin to the elastomer resin is too high, the temporary bonding adhesive in the present application is difficult to soften at the patch temperature, which can easily lead to unsatisfactory patch results.

[0065] In some embodiments of the present application, the temporary bonding adhesive includes an N-substituted maleimide terpolymer resin, an elastomer resin, and a second solvent. Calculated by mass, the N-substituted maleimide terpolymer resin: elastomer resin: second solvent is (3-20): (5-35): (55-90). In this way, the temporary bonding adhesive can have a suitable viscosity at room temperature, which is beneficial to improving the processability of the temporary bonding adhesive. The temporary bonding adhesive in the present invention is based on an N-substituted maleimide terpolymer resin and a low-modulus elastomer resin. It not only has excellent film-forming properties, but also has a high modulus at high temperatures. In chip packaging (such as fan-out packaging), it ensures a strong bonding force between the chip and the temporary bonding film. At the same time, the polarity of the N-substituted maleimide copolymer resin is reduced by ternary copolymerization, which ensures better compatibility between the two main resins, improves the storage stability of the temporary bonding adhesive, and is more convenient in practical applications.

[0066] In some embodiments of the present application, the number average molecular weight of the polymer resin with a styrene end-blocking structure is 30,000 g / mol to 300,000 g / mol. It should be noted that the inventors have found that the number average molecular weight of the polymer resin with a styrene end-blocking structure is too low, which easily leads to unsatisfactory temperature resistance of the temporary bonding adhesive; the number average molecular weight of the polymer resin with a styrene end-blocking structure is too high, which easily leads to the temporary bonding adhesive being difficult to remove. In addition, the molecular weight of the styrene end-blocking polymer resin has little effect on the compatibility between the N-substituted maleimide terpolymer resin and the styrene end-blocking polymer resin, but the styrene content in the styrene end-blocking polymer resin has a greater effect on the binding strength of the temporary bonding adhesive at high temperatures. The higher the styrene content in the styrene end-blocking polymer resin, the stronger the binding strength of the temporary bonding adhesive at high temperatures.

[0067] In some embodiments of the present application, the content of styrene groups in the polymer resin having a styrene-terminated structure (i.e., the content of styrene structural units in the polymer resin having a styrene-terminated structure) is 15 wt % to 60 wt %. For example, the content of styrene groups in the polymer resin having a styrene-terminated structure is 15 wt %, 20 wt %, 25 wt %, 30 wt %, 35 wt %, 40 wt %, 45 wt %, 50 wt %, 55 wt %, 60 wt %, or values between any two of the above values.

[0068] It should be noted that the inventors have discovered that if the content of styrene groups in a polymer resin with a styrene-terminated structure is too low, the polymer resin with a styrene-terminated structure and the temporary bonding adhesive with the polymer resin with a styrene-terminated structure may have unsatisfactory heat resistance; if the content of styrene groups in a polymer resin with a styrene-terminated structure is too high, the polymer resin with a styrene-terminated structure and the temporary bonding adhesive with the polymer resin with a styrene-terminated structure may have greater internal stress, resulting in poor film-forming properties of the resulting temporary bonding adhesive. The content of styrene groups in a polymer resin with a styrene-terminated structure has little or no effect on its compatibility with the N-substituted maleimide terpolymer resin, but will affect the bonding strength of the temporary bonding adhesive at high temperatures.

[0069] In some embodiments of the present application, the elastomeric resin includes at least one of styrene-ethylene-propylene block copolymer (styrene-ethylene / propylene copolymer, SEP), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-butadiene-styrene block copolymer (SIBS), styrene-butadiene-butylene-styrene block copolymer (SBBS), styrene-ethylene-butylene-styrene block copolymer (styrene-ethylene / butylene copolymer, SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-ethylene-propylene-styrene block copolymer (styrene-ethylene / propylene-styrene copolymer, SEPS), and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS). Further, the elastomeric resin includes at least one of styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEPS), and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS).

[0070] In some embodiments of the present application, the second solvent includes solvent D1 and solvent D2. Solvent D1 can be a non-polar solvent, for example, comprising at least one of a linear, branched, or cyclic hydrocarbon solvent having 5 to 18 carbon atoms. Solvent D2 comprises at least one of an ether, cyclic ether, ketone, cyclic ketone, or ester solvent having 3 to 18 carbon atoms. This facilitates better dissolution of the elastomer resin in solvent D1.

[0071] Illustratively, the solvent D1 includes at least one of n-pentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 2,2,4-trimethylpentane, 2,3,4-trimethylpentane, 2,3,3-trimethylpentane, n-hexane, 2-methylhexane, 3-methylhexane, 2,2,5-trimethylhexane, n-heptane, n-octane, nonane, n-decane, undecane, dodecane, methylcyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, cyclooctane, terpane, p-menthane, limonene, tetralin, and decalin. Further, the solvent D1 includes at least one of n-heptane, ethylcyclohexane, cycloheptane, p-menthane, limonene, and decalin.

[0072] For example, solvent D2 can be a polar solvent. Further, solvent D2 includes at least one of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, anisole, tetrahydrofuran, dioxane, dioxane, methyl ethyl ketone, methyl butyl ketone, methylcyclopentanone, cyclohexanone, 4-ethylcyclohexanone, 4,4-dimethylcyclohexanone, isophorone, N-methyl pyrrolidone, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, dimethyl carbonate, γ-butyrolactone, and propylene glycol methyl ether acetate. Further, solvent B includes at least one of ethylene glycol monomethyl ether, tetrahydrofuran, dioxane, ethyl acetate, butyl acetate, γ-butyrolactone, and propylene glycol methyl ether acetate. In this way, it is beneficial to better dissolve the N-substituted maleimide terpolymer resin in solvent D2.

[0073] Furthermore, the ratio of solvent D1 to solvent D2 is 1:(0.1-5). This helps the elastomer resin and N-substituted maleimide terpolymer resin in the temporary bonding adhesive to dissolve faster to form a uniform adhesive solution, thereby improving the production efficiency of the temporary bonding adhesive.

[0074] In some embodiments of the present application, the temporary bonding adhesive also includes at least one of a leveling agent, an antioxidant, and a defoaming agent. It should be noted that the leveling agent is used to improve the surface flatness and smoothness of the coating or film. The leveling agent prevents the coating from having surface defects such as shrinkage holes, cracks, and brush marks by adjusting the fluidity and surface tension of the coating, thereby improving the appearance quality and performance of the coating. Antioxidants are a class of chemical substances that can effectively inhibit or delay the oxidation reaction of materials under the action of oxygen. Defoaming agents are a class of chemical substances that can inhibit or eliminate foam. The specific types of leveling agents, antioxidants, and defoaming agents do not belong to the main improvement points of the present application and are not limited here.

[0075] In some embodiments of the present application, the temporary bonding adhesive further includes a leveling agent, and the content of the leveling agent in the temporary bonding adhesive is 0 to 5 wt %.

[0076] For example, the leveling agent is selected from at least one of BYK 300, BYK306, BYK 310, BYK 320, BYK 322, BYK 323, BYK330, BKY 331, BYK 333, BYK 342, BYK 345, BYK 346, BYK 348, BYK 370, BYK 371, BKY 378, BYK 397, BYK 399, BYK358N, BYK 066N, BYK 3560, BYK 325N, YCK 1200, YCK 1300, YCK1400, Sago6007, and Sago3400; preferably BYK 348, BYK 370, BYK At least one of BYK378, BYK066N, and BYK3560.

[0077] In some embodiments of the present application, the temporary bonding adhesive further includes an antioxidant, and the content of the antioxidant in the temporary bonding adhesive is 0 to 5 wt %.

[0078] Illustratively, the antioxidant is selected from at least one of antioxidant 1010 , antioxidant 1076 , antioxidant 3114 , antioxidant 168 , and antioxidant 626 .

[0079] In some embodiments of the present application, the temporary bonding adhesive further includes a defoaming agent, and the content of the defoaming agent in the temporary bonding adhesive is 0 to 5 wt %.

[0080] Exemplarily, the defoaming agent is selected from one of Defom 6800, SGR1830, BYK034, and BYK1796.

[0081] The present application also provides a method for preparing a temporary bonding adhesive, comprising:

[0082] S210: N-substituted maleimide terpolymer resin, styrene-terminated polymer resin, a second solvent, a leveling agent, an antioxidant, and a defoaming agent are mixed according to a preset ratio to obtain a mixture.

[0083] For example, calculated by weight, the N-substituted maleimide terpolymer resin: styrene-terminated polymer resin: second solvent: leveling agent: antioxidant: defoaming agent is (3-20): (5-35): (55-90): (0-5): (0-5): (0-5).

[0084] S220 degasses the obtained mixture to obtain a temporary bonding adhesive.

[0085] The present application also provides a packaging structure. Figures 3 to 5The packaging structure includes an adhesive film 4, which is formed from the aforementioned temporary bonding adhesive. It is understood that because the N-substituted maleimide terpolymer resin in this application contains an imide ring structure, the glass transition temperature of the hardened temporary bonding adhesive can be increased. Consequently, the hardened temporary bonding adhesive containing the N-substituted maleimide terpolymer resin in this application has a high bonding strength with the chip even at high temperatures, thereby preventing chip displacement under high-temperature conditions such as plastic packaging.

[0086] In some embodiments of this application, please refer to Figure 3 The packaging structure comprises, from bottom to top, a temporary carrier (e.g., a glass carrier 2), a release layer 3, an adhesive film 4, a chip 5, and a plastic layer 7. It should be noted that the specific configuration of the packaging structure does not constitute a major improvement of this application and is not limited here.

[0087] In some embodiments of the present application, the adhesive film is formed by coating the aforementioned temporary bonding adhesive on a release layer and then baking. It should be noted that the coating method of the temporary bonding adhesive can be determined based on the carrier specifications. For example, when the carrier is in the form of a disc, the coating process is preferably spin coating. For another example, when the carrier is in the form of a panel, the coating process is preferably blade coating.

[0088] In some embodiments of the present application, the baking process of the temporary bonding adhesive after coating is not particularly limited, and is preferably baked at 80-120°C for 2 minutes, and then baked at 200-230°C for 4 minutes; further preferably baked at 90°C for 2 minutes, and then baked at 220°C for 4 minutes. The adhesive film prepared using the above method has excellent high-temperature modulus, can significantly improve the bonding strength between the chip and the adhesive film, and can well solve the problem of chip position offset in the plastic packaging process. At the same time, compared with the N-substituted maleimide resin, the N-substituted maleimide terpolymer resin prepared by ternary copolymerization in the present application can reduce the polarity of the N-substituted maleimide resin, ensure better compatibility between the two main resins of the N-substituted maleimide terpolymer resin and the styrene-terminated polymer resin, improve the storage stability of the temporary bonding adhesive, and is more convenient in practical applications.

[0089] Example 1

[0090] First, 173.2g of N-phenylmaleimide, 41.1g of cyclohexene, 52.1g of styrene, and 1000g of toluene were added to a 2L three-necked flask and stirred uniformly. After heating to 70°C, 5.0g of azobisisobutyronitrile was added to initiate a copolymerization reaction. After reacting for 4 hours, the reaction solution was added to ethanol to terminate the reaction and precipitate a polymer. The polymer was repeatedly washed with ethanol until the residual monomers were completely washed out. The polymer was then placed in a vacuum oven and dried to constant weight to obtain an N-phenylmaleimide-cyclohexene-styrene terpolymer resin. The number average molecular weight of the copolymer resin was 4810g / mol. The molar content of each structural unit in the N-phenylmaleimide-cyclohexene-styrene terpolymer resin was calculated using nuclear magnetic resonance spectroscopy. The molar contents of the three copolymer units, N-phenylmaleimide, cyclohexene, and styrene, were 50.1%, 24.8%, and 25.1%, respectively.

[0091] Then, calculated by mass ratio, 8 parts of synthesized N-phenylmaleimide-cyclohexene-styrene copolymer resin, 12 parts of SEBS resin (the number average molecular weight of SEBS resin is 75100 g / mol, and the content of styrene groups is 40.5 wt%), 59 parts of limonene, and 19.5 parts of butyl acetate are added to a mixing container, and then 0.5 parts of BYK348, 0.5 parts of antioxidant 1010 and 0.5 parts of BYK034 are added and stirred and mixed, and then degassed to obtain a temporary bonding adhesive.

[0092] Example 2

[0093] The difference from Example 1 is that when synthesizing the copolymer resin, 41.1 g of cyclohexene monomer is replaced with 47.1 g of bicyclo[2,2,1]hept-2-ene monomer. The number average molecular weight of the prepared N-phenylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene terpolymer resin is 4850 g / mol, and the molar contents of the three copolymer units of N-phenylmaleimide, bicyclo[2,2,1]hept-2-ene, and styrene are 49.7%, 25.0%, and 25.3%, respectively.

[0094] Example 3

[0095] The difference from Example 1 is that when synthesizing the copolymer resin, 52.1 g of styrene monomer is replaced with 47.1 g of bicyclo[2,2,1]hept-2-ene monomer. The number average molecular weight of the prepared N-phenylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene terpolymer resin is 4880 g / mol, and the molar contents of the three copolymer units of N-phenylmaleimide, cyclohexene, and bicyclo[2,2,1]hept-2-ene are 50.2%, 24.9%, and 24.9%, respectively.

[0096] Example 4

[0097] The difference from Example 1 is that when synthesizing the copolymer resin, the mass of N-phenylmaleimide is changed to 86.6 g, the mass of cyclohexene is changed to 82.2 g, and 52.1 g of styrene monomer is replaced by 49.1 g of maleic anhydride monomer. The number average molecular weight of the prepared N-phenylmaleimide-cyclohexene-maleic anhydride terpolymer resin is 4854 g / mol, and the molar contents of the three copolymer units of N-phenylmaleimide, cyclohexene, and maleic anhydride are 24.8%, 49.8%, and 25.4%, respectively.

[0098] Example 5

[0099] This embodiment differs from Example 1 in that 173.2 g of N-phenylmaleimide monomer is replaced with 111.1 g of N-methylmaleimide monomer during the synthesis of the copolymer resin. The resulting N-methylmaleimide-cyclohexene-styrene terpolymer resin has a number average molecular weight of 4798 g / mol, and the molar contents of the three copolymer units, N-methylmaleimide, cyclohexene, and styrene, are 50.1%, 25.0%, and 24.9%, respectively.

[0100] Example 6

[0101] This embodiment differs from Example 1 in that 179.2 g of N-cyclohexylmaleimide monomer is substituted for 173.2 g of N-phenylmaleimide monomer during the synthesis of the copolymer resin. The resulting N-cyclohexylmaleimide-cyclohexene-styrene terpolymer resin has a number average molecular weight of 4820 g / mol, and the molar contents of the three copolymer units, N-cyclohexylmaleimide, cyclohexene, and styrene, are 50.3%, 24.5%, and 25.2%, respectively.

[0102] Example 7

[0103] The difference from Example 1 is that the copolymerization temperature is reduced from 70° C. to 60° C. The number average molecular weight of the prepared N-phenylmaleimide-cyclohexene-styrene terpolymer resin is 6650 g / mol, and the molar contents of the three copolymer units of N-phenylmaleimide, cyclohexene, and styrene are 50.3%, 24.8%, and 24.9%, respectively.

[0104] Example 8

[0105] This embodiment differs from Example 1 in that the mass of cyclohexene and styrene used in the synthesis of the copolymer resin is changed to 65.7 g and 20.8 g, respectively. The resulting N-phenylmaleimide-cyclohexene-styrene terpolymer resin has a number average molecular weight of 4865 g / mol, and the molar contents of the three copolymer units of N-phenylmaleimide, cyclohexene, and styrene are 50.1%, 40.8%, and 9.1%, respectively.

[0106] Example 9

[0107] This embodiment differs from Example 1 in that the mass of cyclohexene and styrene used in the synthesis of the copolymer resin is changed to 16.4 g and 83.3 g, respectively. The resulting N-phenylmaleimide-cyclohexene-styrene terpolymer resin has a number average molecular weight of 4880 g / mol, and the molar contents of the three copolymer units of N-phenylmaleimide, cyclohexene, and styrene are 50.1%, 8.9%, and 41.0%, respectively.

[0108] Example 10

[0109] The difference from Example 1 is that when synthesizing the copolymer resin, the mass of N-phenylmaleimide is changed to 86.6 g, the mass of cyclohexene is changed to 49.3 g, and the mass of styrene is changed to 41.7 g. The number average molecular weight of the prepared N-phenylmaleimide-cyclohexene-styrene terpolymer resin is 4856 g / mol, and the molar contents of the three copolymer units of N-methylmaleimide, cyclohexene, and styrene are 35.5%, 40.2%, and 24.3%, respectively.

[0110] Example 11

[0111] The difference from Example 1 is that the number average molecular weight of the SEBS resin is 98200 g / mol, and the content of styrene groups is 40.9 wt %.

[0112] Example 12

[0113] The difference between this embodiment and Example 1 is that the number average molecular weight of the SEBS resin is 73800 g / mol, and the content of styrene groups is 25.1 wt %.

[0114] Example 13

[0115] The difference from Example 1 is that the SEBS resin is replaced by a SEPS resin, the number average molecular weight of the SEPS resin is 75500 g / mol, and the content of styrene groups is 40.5 wt %.

[0116] Example 14

[0117] The difference from Example 1 is that the SEBS resin is replaced by the SEP resin, the number average molecular weight of the SEP resin is 75680 g / mol, and the content of styrene groups is 41.2 wt %.

[0118] Example 15

[0119] The difference from Example 1 is that the SEBS resin is replaced by SEEPS resin, the number average molecular weight of the SEPS resin is 76100 g / mol, and the content of styrene groups is 40.8 wt %.

[0120] Example 16

[0121] The difference between this embodiment and Example 1 is that the mass fraction of the N-phenylmaleimide-cyclohexene-styrene copolymer resin in the temporary bonding adhesive is 2, and the mass fraction of the SEBS resin is 18.

[0122] Example 17

[0123] The difference between this embodiment and Example 1 is that the mass fraction of the N-phenylmaleimide-cyclohexene-styrene copolymer resin in the temporary bonding adhesive is 12, and the mass fraction of the SEBS resin is 8.

[0124] Example 18

[0125] The difference from Example 1 is that the mass fraction of limonene in the temporary bonding adhesive is 69, the mass fraction of butyl acetate is 9, and the mass fraction of BYK348 is 1.

[0126] Comparative Example 1

[0127] Calculated by mass ratio, 20 parts of SEBS resin (the number average molecular weight of SEBS resin is 75100 g / mol, and the content of styrene groups is 40.5 wt%), 59 parts of limonene, and 19.5 parts of butyl acetate are added to a mixing container, and then 0.5 parts of BYK348, 0.5 parts of antioxidant 1010, and 0.5 parts of BYK034 are added and stirred and mixed, and then degassed to obtain a temporary bonding adhesive.

[0128] Comparative Example 2

[0129] The difference between this embodiment and Comparative Example 1 is that the number average molecular weight of the SEBS resin in the temporary bonding adhesive is 98,200 g / mol, and the content of styrene groups is 40.9 wt %.

[0130] Comparative Example 3

[0131] The difference between this embodiment and Comparative Example 1 is that the number average molecular weight of the SEBS resin in the temporary bonding adhesive is 73,800 g / mol, and the content of styrene groups is 25.1 wt %.

[0132] Comparative Example 4

[0133] The difference between this embodiment and Comparative Example 1 is that the SEBS resin in the temporary bonding adhesive is replaced by a SEPS resin, the number average molecular weight of the SEPS resin is 75,500 g / mol, and the content of styrene groups is 40.5 wt %.

[0134] Comparative Example 5

[0135] The difference between this embodiment and comparative example 1 is that the SEBS resin in the temporary bonding adhesive is replaced by SEP resin, the number average molecular weight of the SEP resin is 75680 g / mol, and the content of styrene groups is 41.2 wt %.

[0136] Comparative Example 6

[0137] The difference between the comparative example 1 and the comparative example 1 is that the SEBS resin in the temporary bonding adhesive is replaced by SEEPS resin, the number average molecular weight of the SEEPS resin is 76100 g / mol, and the content of styrene groups is 40.8 wt %.

[0138] Comparative Example 7

[0139] This embodiment differs from Example 1 in that an N-phenylmaleimide-cyclohexene binary copolymer resin is used in place of the N-phenylmaleimide-cyclohexene-styrene terpolymer resin in preparing the temporary bonding adhesive. The N-phenylmaleimide-cyclohexene binary copolymer resin has a number average molecular weight of 4510 g / mol and a molar content of N-phenylmaleimide copolymer units of 49.8%.

[0140] Comparative Example 8

[0141] This embodiment differs from Example 1 in that an N-phenylmaleimide-styrene binary copolymer resin is used in place of the N-phenylmaleimide-cyclohexene-styrene terpolymer resin in preparing the temporary bonding adhesive. The N-phenylmaleimide-styrene binary copolymer resin has a number average molecular weight of 4750 g / mol and a molar content of N-phenylmaleimide copolymer units of 49.6%.

[0142] The difference between Examples 1 to 24 and Comparative Examples 1 to 2 is that the temporary bonding adhesives prepared are different, as shown in Tables 1 and 2; wherein, the structural unit ratio in N-substituted maleimide copolymer resin 1 (i.e., PI-1 to PI-10 in Table 1) represents the molar ratio of N-substituted maleimide unit (A): first olefin monomer unit (B): second olefin monomer unit (C) in the terpolymer. Taking PI-1 as an example, the PI-1 structural unit ratio of 50.1 / 24.8 / 25.1 means that in the PI-1 molecular structure, the molar ratio of N-substituted maleimide unit: cyclohexene monomer unit: styrene monomer unit is 50.1:24.8:25.1. The unit ratio in styrene-terminated polymer resin 2 (i.e., SEBS-1 to SEEPS in Table 1) represents the mass percentage of styrene structural units (i.e., styrene groups) in styrene-terminated polymer resin 2. Taking SEBS-1 as an example, a SEBS-1 structural unit ratio of 40.5% indicates that the mass percentage of styrene structural units in SEBS-1 is 40.5%. The temporary bonding adhesives prepared in each experimental example were tested for high-temperature mechanical properties and chip position shift. The test results are shown in Table 3.

[0143] Table 1

[0144]

[0145] Table 2

[0146]

[0147]

[0148] Table 2

[0149]

[0150]

[0151] Experimental testing

[0152] Molecular weight test of the resin: APC was used to characterize the molecular weight of the resin. The mobile phase was toluene at a flow rate of 0.5 mL / min.

[0153] Copolymer resin component content test: Nuclear magnetic resonance spectrometer was used to test and calculate the component content of the copolymer resin, and the solvent was deuterated chloroform.

[0154] Storage stability monitoring of temporary bonding adhesives: The prepared temporary bonding adhesives are tested for viscosity every 7 days. If the viscosity change of the adhesive is less than 10% of the initial viscosity, it is considered that the adhesive has not deteriorated; otherwise, it has deteriorated.

[0155] Storage modulus test of temporary bonding adhesive film: DMA was used to characterize the storage modulus of the sample. The test frequency was 1 Hz and the scanning speed was 3 ° C / min. The test results are as follows: Figure 1 shown.

[0156] Chip placement process: SMT placement machine is used for placement, the nozzle temperature is 230℃, the base temperature is 120℃, the placement pressure is 20N, and the placement duration is 3s.

[0157] Chip bonding test: Figure 2 As shown, the sample to be tested is fixed on the support platform 1, and a push-pull tester is used to test the bonding strength between the chip 5 and the adhesive film 4. The test temperature is 150°C, and the moving speed of the test pusher 6 is 100 μm / s.

[0158] Plastic sealing process: The plastic sealing temperature is 150℃, the pressure is 6MPa, and the vacuum degree is 0.3Torr.

[0159] Chip offset test: Randomly select a chip from the top, bottom, left, right, and center of the encapsulated glass carrier 2. Use an optical microscope to measure the chip offset in the X and Y directions. The chip offset is the sum of the chip offsets in the X and Y directions. The average of the five chip test results is the final chip offset result.

[0160] Table 3

[0161]

[0162] Table 3

[0163]

[0164] ×: Chip dropped

[0165] The difference between Examples 1 to 18 and Comparative Examples 1 to 8 lies in whether N-substituted maleimide terpolymer resin 1 is added to the prepared adhesive film. From the test results in Table 3 above, it can be seen that the addition of N-substituted maleimide terpolymer resin 1 can effectively improve the bonding force between the adhesive film and the chip, and the higher the proportion of N-substituted maleimide terpolymer resin 1, the smaller the chip position offset. The possible reason is that the position offset of the chip after plastic encapsulation is related to the bonding force between the adhesive film and the chip, and the bonding force between the adhesive film and the chip is closely related to the high-temperature modulus of the adhesive film. The temporary bonding adhesive films prepared in Examples 1 to 18 have a high storage modulus at 150°C, the chip position offset after the plastic encapsulation process is small, and the storage stability is good.

[0166] The difference between Examples 1 to 6 lies in the different compositions of the N-substituted maleimide terpolymer resin 1. As can be seen from the test results in Table 3, the rigidity of the olefinic monomer in the N-substituted maleimide terpolymer resin 1 has a certain influence on the bonding force between the adhesive film and the chip and the chip position offset. The stronger the rigidity of the olefinic monomer, the greater the bonding force between the adhesive film and the chip, and the smaller the chip position offset.

[0167] The difference between Example 1, Example 7, and Example 10 lies in the different molecular weights of the N-substituted maleimide terpolymer resins and the ratios of different structural units. As can be seen from the test results in Table 3, the higher the molecular weight of the N-substituted maleimide terpolymer resin or the greater the content of the N-substituted maleimide structural units, the greater the bonding strength between the adhesive film and the chip, and the smaller the chip position shift.

[0168] Comparing the results of Example 1 and Examples 11-15, it can be seen that the molecular weight and resin type of the styrene-terminated polymer resin 2 have little effect on the chip position offset, but the higher the content of the styrene structural unit, the smaller the chip position offset.

[0169] Comparing the results of Example 1 and Example 18, it can be seen that the changes in the solvent ratio, antioxidant, leveling agent and defoaming agent have little effect on the positional deviation of the chip.

[0170] It is also worth noting that, by comparing Example 1 and Example 17, it can be concluded that if the proportion of N-substituted maleimide terpolymer resin 1 is too high, resulting in excessively high high-temperature modulus of the temporary bonding adhesive film, the chip bonding effect will be affected, leading to bonding failure.

[0171] The difference between Example 1 and Comparative Examples 1 and 2 lies in the different N-substituted maleimide copolymers added. As can be seen from Table 3, the storage stability of the temporary bonding adhesive is related to the structure of the N-substituted maleimide copolymer unit, and the stability of the temporary bonding adhesive after introducing the N-substituted maleimide terpolymer resin is significantly better than that after introducing the N-substituted maleimide binary copolymer resin.

[0172] The above is a detailed introduction to the technical solutions provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An N-substituted maleimide terpolymer resin, characterized in that The invention comprises an N-substituted maleimide unit, a first olefin monomer unit and a second olefin monomer unit; wherein the first olefin monomer unit and the second olefin monomer unit have different structures.

2. The N-substituted maleimide terpolymer resin according to claim 1, wherein The N-substituted maleimide monomer forming the N-substituted maleimide unit is a compound having a structure represented by the following formula (1); The substituent R1 includes one of a straight-chain alkyl group or a substituent thereof, a branched-chain alkyl group or a substituent thereof, a cycloalkyl group or a substituent thereof, and an aryl group or a substituent thereof.

3. The N-substituted maleimide terpolymer resin according to claim 2, wherein R1 includes one of a linear alkyl group having 1 to 6 carbon atoms or a substituent thereof, a branched alkyl group having 3 to 6 carbon atoms or a substituent thereof, a cycloalkyl group having 3 to 12 carbon atoms or a substituent thereof, and an aryl group having 6 to 20 carbon atoms or a substituent thereof; Preferably, R1 includes one of methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, chloromethyl, dichloromethyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, phenyl, benzyl, methylphenyl, dimethylphenyl, trimethylphenyl, naphthyl, and anthracenyl; Preferably, the N-substituted maleimide monomer is one of N-methylmaleimide, N-ethylmaleimide, N-tert-butylmaleimide, N-cyclopentylmaleimide, N-cyclohexylmaleimide, and N-phenylmaleimide.

4. The N-substituted maleimide terpolymer resin according to any one of claims 1 to 3, wherein The first olefin monomer forming the first olefin monomer unit includes one of α-olefin and its substituents, cycloolefin and its substituents, bridged cyclic olefin and its substituents; and / or The second olefin monomer forming the second olefin monomer unit includes one of α-olefin and its substituents, cycloolefin and its substituents, bridged cyclic olefin and its substituents; and / or The number average molecular weight of the N-substituted maleimide terpolymer resin is 2000 g / mol to 8000 g / mol.

5. The N-substituted maleimide terpolymer resin according to claim 4, wherein The first olefin monomer or the second olefin monomer is independently butene, isobutylene, butadiene, pentene, vinyl chloride, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, 1-methylcyclopentene, 1-methylcyclohexene, bicyclo[2,2,1]hept-2-ene, 1-methylbicyclo[2,2,1]hept-2-ene, 5-methylbicyclo[2,2,1]hept-2-ene, 7-methyl The present invention is one of 1-ethylbicyclo[2,2,1]hept-2-ene, 1-ethylbicyclo[2,2,1]hept-2-ene, 5-ethylbicyclo[2,2,1]hept-2-ene, 1-propylbicyclo[2,2,1]hept-2-ene, 5-propylbicyclo[2,2,1]hept-2-ene, 1-butylbicyclo[2,2,1]hept-2-ene, and 5-butylbicyclo[2,2,1]hept-2-ene, wherein the structures of the first olefinic monomer and the second olefinic monomer are different.

6. The N-substituted maleimide terpolymer resin according to any one of claims 1 to 3, wherein The molar amount of the N-substituted maleimide unit in the N-substituted maleimide terpolymer resin is A, the molar number of the first olefin monomer unit in the N-substituted maleimide terpolymer resin is B, and the molar number of the second olefin monomer unit in the N-substituted maleimide terpolymer resin is C, then A:B:C is 1:(0.1~10):(0.1~10).

7. The N-substituted maleimide terpolymer resin according to claim 6, wherein The molar percentage of N-substituted maleimide units in the N-substituted maleimide terpolymer resin is 15% to 75%, preferably, the molar percentage of N-substituted maleimide units is 20% to 55%; and / or, the molar percentage of the first olefin monomer unit in the N-substituted maleimide terpolymer resin is 5% to 75%, preferably, the molar percentage of the first olefin monomer unit is 5% to 55%; And / or, the molar percentage of the second olefin monomer unit in the N-substituted maleimide terpolymer resin is 5% to 75%, preferably, the molar percentage of the second olefin monomer unit is 5% to 55%.

8. The N-substituted maleimide terpolymer resin according to any one of claims 1 to 3, wherein N-substituted maleimide terpolymer resins include N-phenylmaleimide-butadiene-styrene copolymers, N-phenylmaleimide-hexene-styrene copolymers, N-phenylmaleimide-cyclohexene-styrene copolymers, N-phenylmaleimide-maleic anhydride-styrene copolymers, N-phenylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymers, N-phenylmaleimide-5-methylbicyclo[2,2,1]hept-2-ene-styrene copolymers, N-phenylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymers, N-phenylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymers Polymers, N-phenylmaleimide-cyclohexene-maleic anhydride, N-phenylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymers, N-phenylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymers, N-phenylmaleimide-cyclopentene-cyclohexene copolymers, N-phenylmaleimide-cyclohexene-cycloheptene copolymers, N-phenylmaleimide-cyclohexene-cyclooctene copolymers, N-phenylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymers, N-phenylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymers, N-phenylmaleimide-cyclohexene olefin-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-butadiene-styrene copolymer, N-methylmaleimide-hexene-styrene copolymer, N-methylmaleimide-cyclohexene-styrene copolymer, N-methylmaleimide-maleic anhydride-styrene copolymer, N-methylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, N-methylmaleimide-5-methylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-methylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-methylmaleimide-cyclohexene-bicyclo[2,2,1] Hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclopentene-cyclohexene copolymer, N-methylmaleimide-cyclohexene-cycloheptene copolymer, N-methylmaleimide-cyclohexene-cyclooctene copolymer, N-methylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-methylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-butadiene-styrene copolymer, N-cyclohexylmaleimide-hexene-styrene copolymer, N-cyclohexylmaleimide-cyclohexene-styrene copolymer, N-cyclohexylmaleimide-maleic anhydride-styrene copolymer, N-cyclohexylmaleimide-bicyclo[2,2,1]hept-2-ene-styrene copolymer, N-cyclohexylmaleimide-5-methylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-cyclohexylmaleimide-5-butylbicyclo[2,2,1]hept-2-ene-styrene copolymer, N-cyclohexylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide At least one of N-cyclohexylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-cyclopentene-cyclohexene copolymer, N-cyclohexylmaleimide-cyclohexene-cycloheptene copolymer, N-cyclohexylmaleimide-cyclohexene-cyclooctene copolymer, N-cyclohexylmaleimide-cyclohexene-bicyclo[2,2,1]hept-2-ene copolymer, N-cyclohexylmaleimide-cyclohexene-5-methylbicyclo[2,2,1]hept-2-ene copolymer, and N-cyclohexylmaleimide-cyclohexene-5-butylbicyclo[2,2,1]hept-2-ene copolymer.

9. A temporary bonding adhesive, characterized in that: The temporary bonding adhesive comprises the N-substituted maleimide terpolymer resin according to any one of claims 1 to 8.

10. The temporary bonding adhesive according to claim 9, wherein The temporary bonding adhesive further comprises an elastomeric resin; Preferably, the elastomer resin is a polymer resin having a styrene end-capping structure; Preferably, the mass ratio of the N-substituted maleimide terpolymer resin to the elastomer resin is (3-20):(5-35).

11. The temporary bonding adhesive according to claim 10, wherein The content of styrene structural units in the polymer resin with styrene end-capping structure is 15wt% to 60wt%; And / or, the temporary bonding adhesive further includes at least one of a leveling agent, an antioxidant, and a defoaming agent.

12. An adhesive film, characterized in that: The adhesive film is formed by curing the temporary bonding adhesive according to any one of claims 9 to 11.

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