Preparation method of polyamide-imide-polyimide copolymer resin binder and semiconductor element temporary packaging adhesive film

Abstract

The invention discloses a preparation method of a polyamide-imide-polyimide copolymer resin binder and a semiconductor element temporary packaging adhesive film, and the preparation method comprises the following steps: under the protection of inert gas, dissolving flexible long-chain aromatic diamine, siloxane diamine and 4, 4 '-dithio diphenylamine in a polar organic solvent, and stirring to obtain a mixed solution; the preparation method comprises the following steps: adding an acid-binding agent, uniformly stirring and mixing in an ice bath, adding trimellitic anhydride acyl chloride for reaction, heating to 15-45 DEG C, adding flexible long-chain dianhydride for reaction, adding an end-capping reagent for end capping, and diluting; adding a catalyst and a water absorbent into the diluted reaction liquid to carry out imidization treatment to obtain polyamide-imide-polyimide copolymer resin; diluting the polyamideimide-polyimide copolymer resin adhesive until the solid content is 15-25%, adding siloxane epoxy resin, and uniformly stirring and mixing, so as to obtain the polyamideimide-polyimide copolymer resin adhesive. The heat-resistant adhesive has excellent heat resistance and cohesiveness, and no adhesive residue exists in the stripping process.

Description

Technical Field

[0001] The invention belongs to the technical field of polyester resin adhesives, and in particular relates to a preparation method of a polyamideimide-polyimide copolymer resin adhesive and a temporary packaging adhesive film for semiconductor elements. Background Art

[0002] As semiconductor devices are moving towards smaller and higher capacity, the supporting components used in semiconductor devices are becoming more sophisticated. Traditional silver paste is used to bond or fix semiconductor devices, but there are problems such as leakage and tilting of the device. Therefore, adhesive film is widely used as a substitute, especially in the lead welding process, where adhesive film can effectively avoid failures caused by silver paste, bubble generation and difficulty in thickness control.

[0003] The adhesive film consists of an adhesive layer covering a base film layer. The adhesives currently used in the market mainly include acrylate adhesives and epoxy resin adhesives. Acrylic adhesives and epoxy resin adhesives each have their own disadvantages. The disadvantages of acrylate adhesives mainly include: the adhesive layer is hard and brittle, which means that it does not perform well when subjected to impact and vibration, and special attention needs to be paid to prevent cracking or damage; the curing shrinkage rate is large, which will result in more processing or repair during use to achieve the required precision; the water resistance and solvent resistance are poor, and it may be easier to lose the adhesive effect when exposed to water or solvents.

[0004] The main disadvantages of epoxy resin adhesives include: slow curing speed; high strength and hardness after hardening, which makes it relatively brittle and easy to break or damage. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing a polyamideimide-polyimide copolymer resin adhesive, which has excellent heat resistance and adhesion and has no residual adhesive after peeling.

[0006] Another object of the present invention is to provide a semiconductor element temporary packaging adhesive film, in which the polyamideimide-polyimide copolymer resin adhesive of the present invention is used in the adhesive layer, and the film has good formability, no residual adhesive after peeling, and good low-temperature adhesion.

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

[0008] The present invention provides a method for preparing a polyamideimide-polyimide copolymer resin binder, the preparation method comprising the following steps:

[0009] (1) Under the protection of inert gas, a flexible long-chain aromatic diamine monomer, a siloxane diamine monomer and 4,4'-dithiodiphenylamine are dissolved in a polar organic solvent, an acid binding agent is added, and the mixture is stirred and mixed evenly in an ice bath, and then trimellitic anhydride chloride is added to react for 1.5 to 2.5 hours, and then the temperature is raised to 15 to 45° C., and a flexible long-chain dianhydride monomer is added, and the mixture is stirred and reacted for 5 to 6 hours, and then a capping agent is added to cap the mixture, and then the mixture is diluted to a solid content of 2 to 5%;

[0010] (2) adding a catalyst and a water absorbent to the diluted reaction solution, stirring and reacting at 75-85° C. for 2-3 hours to perform imidization treatment, then pouring the reaction solution into water for precipitation, centrifuging, washing, and drying to obtain a polyamideimide-polyimide copolymer resin;

[0011] (3) diluting the polyamideimide-polyimide copolymer resin to a solid content of 15-25%, adding the siloxane epoxy resin and stirring and mixing evenly to obtain the polyamideimide-polyimide copolymer resin adhesive.

[0012] The rotational viscosity of the polyamideimide-polyimide copolymer resin is 18000-20000 mPa·s, and the glass transition temperature is 185-195°C. If the viscosity is lower than 18000 mPa·s, the adhesive film made of the polyamideimide-polyimide copolymer resin adhesive has poor heat resistance and poor adhesion to the semiconductor; if the viscosity is higher than 20000 mPa·s, the adhesive film is difficult to tear off and there will be residual adhesive; if the glass transition temperature is higher than 195°C, it cannot meet specific processing requirements, and if it is too low, it will affect the bonding with the frame.

[0013] The molar ratio of the flexible long-chain aromatic diamine monomer, the siloxane diamine monomer and the 4,4'-dithiodiphenylamine is 8-9:1:1-2.

[0014] The molar ratio of the acid binding agent: flexible long-chain dianhydride monomer: end-capping agent: catalyst: water absorbent: (flexible long-chain aromatic diamine monomer+siloxane diamine monomer+4,4'-dithiodiphenylamine) is 1.0-1.5: 0.95-0.99: 0.015-0.025: 0.45-0.55: 1.45-1.55: 1; the molar ratio of trimellitic anhydride chloride: flexible long-chain dianhydride monomer is 1.0-2.5: 1.

[0015] Furthermore, the molar ratio of acid binding agent: flexible long-chain dianhydride monomer: end-capping agent: catalyst: water absorbent: (flexible long-chain aromatic diamine monomer+siloxane diamine monomer+4,4'-dithiodiphenylamine) is preferably 1.33:0.97-0.99:0.02:0.5:1.5:1.

[0016] The flexible long-chain aromatic diamine monomer is any one or more of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4′-diaminodiphenyl ether, 2,2′-bis[4-(4-aminophenoxy)phenyl]ether, and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane.

[0017] The siloxane diamine monomer is at least one of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane or α,ω-diaminoalkane.

[0018] Furthermore, the α,ω-diaminoalkane is 1,12-diaminododecane or 1,6-diaminohexane.

[0019] The acid binding agent is at least one of triethylamine and N,N-diisopropylethylamine;

[0020] The polar organic solvent is at least one of N,N-dimethylacetamide, N-methylpyrrolidone, N,N-dimethylformamide and m-cresol.

[0021] The end-capping agent is phthalic anhydride.

[0022] The flexible long-chain dianhydride monomer is any one or more of bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4,4'-diphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride.

[0023] The catalyst is at least one of isoquinoline and pyridine.

[0024] The water absorbing agent is acetic anhydride.

[0025] The mass of the silicone epoxy resin is 6-10% of the mass of the polyamideimide-polyimide copolymer resin.

[0026] The siloxane epoxy resin is Shin-Etsu-KBE903 or Shin-Etsu-KBE9103.

[0027] The present invention also provides an adhesive film for temporary packaging of semiconductor elements, wherein the adhesive layer of the adhesive film is made of a polyamideimide-polyimide copolymer resin adhesive prepared by the preparation method of the present invention.

[0028] In the preparation method of the polyamideimide-polyimide copolymer resin binder provided by the present invention, trimellitic anhydride chloride, flexible long-chain dianhydride monomer, flexible long-chain aromatic diamine monomer, siloxane diamine monomer and sulfur-containing diamine monomer 4,4'-dithiodiphenylamine are polymerized and then subjected to imidization treatment to obtain the polyamideimide-polyimide copolymer resin, which has an absolute viscosity of 18000-20000 mPa·s, a glass transition temperature of 185-195° C., and a stable imide group structure. The polyamideimide-polyimide copolymer resin can be used as a binder to provide good heat resistance and mechanical properties for the bonded lead frame, the amide group has a large polarity and can provide strong bonding force, and the amide group can also undergo coupling reaction with the siloxane epoxy resin to further strengthen the performance of the resin.

[0029] In the preparation method of the polyamideimide-polyimide copolymer resin binder provided by the present invention, the molar amount of the flexible long-chain dianhydride monomer is controlled to be slightly lower than that of the diamine monomer, so that the molecular weight of the obtained resin will not be too high, and the terminal amino group of the obtained polyamideimide-polyimide copolymer resin can continue to react with the siloxane epoxy resin, which can ensure that the obtained polyamideimide-polyimide copolymer resin binder has sufficient bonding force for the lead frame and no residual glue will be left after peeling.

[0030] In the preparation method of the polyamide-imide-polyimide copolymer resin binder provided by the present invention, in step (1), a low-temperature stirring reaction is carried out in an ice bath at 0-5°C, so that the trimellitic anhydride chloride can be prevented from exothermic hydrolysis, which is conducive to the reaction. The solid content at the beginning of the reaction is controlled at 18-22%, and the solid content is diluted to 2%-5% after the reaction. Too low solid content easily leads to too low viscosity of the polyamic acid solution, and too high solid content easily leads to too high viscosity of the polyamic acid solution and even gelation.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The polyamideimide-polyimide copolymer resin adhesive provided by the present invention is mainly used for temporary packaging of semiconductors, has suitable heat resistance, has good adhesion to lead frames, and does not leave adhesive residue, and has no adverse effects on the components themselves.

[0033] In the process of preparing polyamideimide-polyimide copolymer resin, the present invention uses sulfur-containing diamine monomer 4,4'-dithiodiphenylamine as a raw material, which makes the polyamideimide-polyimide copolymer resin structure more flexible and can form a special sulfur-metal bond with metal, thereby improving the bonding force of the binder to various metal surfaces.

[0034] The polyamideimide-polyimide copolymer resin adhesive provided by the present invention adds silane epoxy resin to the polyamideimide-polyimide copolymer resin diluent, thereby enhancing the direct adhesion between the adhesive and the film, preventing the adhesive from being debonded on the component and being entirely attached to the component surface. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the embodiments.

[0036] The brand of the siloxane epoxy resin used in each embodiment and comparative example is Shin-Etsu-KBE903.

[0037] The corresponding abbreviations of the substances in the embodiments and comparative examples are as follows:

[0038] BAPP: 2,2-bis[4-(3-aminophenoxy)phenyl]propane;

[0039] t-Si: 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane;

[0040] TMAC: 1,2,4-trimellitic anhydride chloride;

[0041] S-1: bis(2-aminophenyl) disulfide;

[0042] S-2: 4,4'-dithiodiphenylamine;

[0043] C-12: 1,12-diaminododecane;

[0044] BPADA: 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride).

[0045] Example 1

[0046] A method for preparing a polyamideimide-polyimide copolymer resin binder comprises the following steps:

[0047] (1) Under nitrogen protection and in an ice bath, 0.08 mol BAPP, 0.01 mol 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and 0.01 mol 4,4'-dithiodiphenylamine were dissolved in 220 ml dimethylacetamide, stirred at room temperature until completely dissolved, 13 ml triethylamine was added, stirred and mixed in an ice bath, and then 0.049 mol trimellitic anhydride chloride was added in batches. After complete dissolution, the mixture was brought to room temperature, and 0.049 mol BPADA was added in batches. The mixture was stirred at room temperature for 2 h, 0.002 mol phthalic anhydride was added for end-capping, and stirring was continued at room temperature for 0.5 h. 700 ml dimethylacetamide was added to dilute the mixture to a solid content of 5%, and stirred for 0.5 h.

[0048] (2) adding 0.15 mol of acetic anhydride and 0.05 mol of isoquinoline to the diluted reaction solution, stirring and reacting at 80° C. for 2 h to perform imidization, then pouring the imidization reaction solution into water for precipitation, centrifuging, washing with ethanol, and vacuum drying at 150° C. for 12 h to obtain a polyamideimide-polyimide copolymer resin;

[0049] (3) Diluting the polyamideimide-polyimide copolymer resin with N-methylpyrrolidone to a solid content of 20%, adding the siloxane epoxy resin and stirring to mix evenly to obtain a polyamideimide-polyimide copolymer resin adhesive, wherein the mass of the siloxane epoxy resin is 6% of the mass of the polyamideimide-polyimide copolymer resin.

[0050] Example 2

[0051] The BAPP in Example 1 was adjusted to 0.07 mol, the 4,4'-dithiodiphenylamine was adjusted to 0.02 mol, and the rest remained unchanged.

[0052] Comparative Example 1

[0053] The amounts of TMAC, BPADA and BAPP in Example 1 were adjusted to 0.051 mol, 0.51 mol and 0.08 mol respectively, and the rest remained unchanged.

[0054] Comparative Example 2

[0055] The amounts of TMAC, BPADA and BAPP in Example 1 were adjusted to 0.047 mol, 0.47 mol and 0.08 mol respectively, and the rest remained unchanged.

[0056] Comparative Example 3

[0057] The BAPP in Example 1 was adjusted to 0.09 mol, and the 4,4'-dithiodiphenylamine in the raw material was omitted, while the rest remained unchanged.

[0058] Comparative Example 4

[0059] The 4,4'-diphenylamine disulfide in Example 1 was replaced with bis(2-aminophenyl) disulfide, and the rest remained unchanged.

[0060] Some of the raw materials used in the embodiments and comparative examples are shown in Table 1.

[0061] Table 1

[0062]

[0063] The rotational viscosity and glass transition temperature of the reaction solution after imidization in the above-mentioned embodiments and comparative examples were tested, and the test results are shown in Table 2.

[0064] Rotational viscosity test: The testing instrument is a rotational viscometer, model NDJ-79B, and the merchant is Shanghai Changji Geological Instrument Co., Ltd.

[0065] Glass transition temperature Tg: The test instrument is a differential scanning calorimeter, the equipment model is DSC100A, and the binder Tg point is tested at a nitrogen flow rate of 70 mL / min, a heating rate of 20 degrees / min, and a temperature range of 100-400 degrees.

[0066] Table 2

[0067] Rotational viscosity Tg Example 1 19986mpa*s 194℃ Example 2 19452mpa*s 186℃ Comparative Example 1 24251mpa*s 195℃ Comparative Example 2 14837mpa*s 196℃ Comparative Example 3 20205mpa*s 217℃ Comparative Example 4 20006mpa*s 196℃

[0068] Application Examples

[0069] The polyamideimide-polyimide copolymer resin adhesive prepared in each embodiment and comparative example was coated on a 25 μm polyimide film with a thickness of 1-1.5 μm, rolled up and aged in an oven at 100 degrees for two days to obtain an adhesive film.

[0070] The adhesive film was bonded to the C19400 copper alloy lead frame at 25°C and a pressure of 20N. The bonded C19400 copper alloy lead frame was heated in an oven at 180°C for 60 minutes and 200°C for 60 minutes in an air environment. Then, the bonding surface was plasma treated in an argon environment at an argon flow rate of 20sccm, 150W, and 15 seconds.

[0071] The sealing was performed using a molding machine at 175°C, 6.8 MPa, and 2 minutes, and a sealing material (trade name: GE-7470L-A, manufactured by Hitachi Chemical Co., Ltd.) was used to form a sealing layer on the surface of the lead frame and the adhesive film adhesive layer. After that, the adhesive film was peeled off at a speed of 50 mm / min in the 180° direction, and the state of the residual glue on the sealing layer and the lead frame after peeling was confirmed. According to the ratio of the area of ​​the residual glue portion to the total area of ​​the surface of the sealing layer and the lead frame, the residual glue rate and the film breakage rate were evaluated in 6 levels according to the following standards:

[0072] The levels of residual glue rate are as follows:

[0073] 5: The residual adhesive rate is 60-100%, and the remaining adhesive layer is relatively thick overall;

[0074] 4: The residual adhesive rate is 60-100%, and the remaining adhesive layer is relatively thin overall;

[0075] 3: The residual glue rate is more than 30% and less than 60%;

[0076] 2: The residual glue rate is more than 10% and less than 30%;

[0077] 1: The residual glue rate exceeds 0% and is less than 10%;

[0078] 0: Residual glue rate 0%.

[0079] The levels of film breakage rate are as follows:

[0080] 5*: Film breaking rate is 60-100%, and the film is basically broken at the beginning of film peeling;

[0081] 4*: Film breaking rate 60-100%, the film will be broken after peeling off the film;

[0082] 3*: The film breaking rate is more than 30% and less than 60%;

[0083] 2*: The film breaking rate is more than 10% and less than 30%;

[0084] 1*: The film breakage rate is more than 0% and less than 10%;

[0085] 0*: Film breakage rate 0%.

[0086] The results of residual glue rate and film breakage rate are shown in Table 3.

[0087] Table 3

[0088] Film breaking rate Residual glue rate Peel force Example 1 0 0 151gf Example 2 0 0 210gf Comparative Example 1 2 2 162gf Comparative Example 2 2 5 64gf Comparative Example 3 3 1 87gf Comparative Example 4 0 4 161gf

[0089] It can be seen from the data in the above table that the polyamide-imide resin adhesive provided by the present invention has excellent low-temperature adhesion and low residual adhesive rate.

[0090] In Comparative Example 1, since the molar ratio of the dianhydride monomer to the diamine monomer exceeds the range of 0.95 to 0.99:1, the molecular weight and viscosity of the polyamideimide-polyimide copolymer resin increase, which in turn leads to an increase in the viscosity of the polyamideimide-polyimide copolymer resin adhesive, and excessively high residual adhesive rate and film breakage rate.

[0091] In Comparative Example 2, since the molar ratio of the dianhydride monomer to the diamine monomer is lower than the range of 0.95 to 0.99:1, the viscosity of the polyamideimide-polyimide copolymer resin is reduced, and the adhesive residue rate and film breakage rate of the prepared polyamideimide-polyimide copolymer resin are too high.

[0092] In Comparative Example 3, since 4,4′-dithiodiphenylamine was not added as the sulfur-containing diamine monomer, the film breaking rate of the polyamideimide-polyimide copolymer resin adhesive was too high.

[0093] In Comparative Example 4, since 4,4'-diphenylamine disulfide was replaced by bis(2-aminophenyl) disulfide, the residual adhesive rate of the polyamideimide-polyimide copolymer resin adhesive was significantly increased.

[0094] The detailed description of the preparation method of a polyamideimide-polyimide copolymer resin adhesive and a temporary packaging adhesive film for semiconductor components with reference to the above-mentioned embodiments is illustrative rather than restrictive, and several embodiments can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for preparing a polyamideimide-polyimide copolymer resin binder, characterized in that: The preparation method comprises the following steps: (1) Under the protection of inert gas, a flexible long-chain aromatic diamine monomer, a siloxane diamine monomer and 4,4'-dithiodiphenylamine are dissolved in a polar organic solvent, an acid binding agent is added, and the mixture is stirred and mixed evenly in an ice bath, and then trimellitic anhydride chloride is added to react for 1.5 to 2.5 hours, and then the temperature is raised to 15 to 45° C., and a flexible long-chain dianhydride monomer is added, and the mixture is stirred and reacted for 5 to 6 hours, and then a capping agent is added to cap the mixture, and then the mixture is diluted to a solid content of 2 to 5%; (2) adding a catalyst and a water absorbent to the diluted reaction solution, stirring and reacting at 75-85° C. for 2-3 hours, then pouring the reaction solution into water for precipitation, centrifuging, washing, and drying to obtain a polyamideimide-polyimide copolymer resin; (3) diluting the polyamideimide-polyimide copolymer resin to a solid content of 15-25%, adding the siloxane epoxy resin and stirring and mixing evenly to obtain the polyamideimide-polyimide copolymer resin adhesive.

2. The preparation method according to claim 1, characterized in that: The polyamideimide-polyimide copolymer resin has a rotational viscosity of 18000-20000 mPa·s and a glass transition temperature of 185-195°C.

3. The preparation method according to claim 1, characterized in that: The molar ratio of the flexible long-chain aromatic diamine monomer, the siloxane diamine monomer, and the 4,4'-dithiodiphenylamine is 8-9:1:1-2; the molar ratio of the acid binding agent: the flexible long-chain dianhydride monomer: the end-capping agent: the catalyst: the water absorbent: (flexible long-chain aromatic diamine monomer+siloxane diamine monomer+4,4'-dithiodiphenylamine) is 1.0-1.5:0.95-0.99:0.015-0.025:0.45-0.55:1.45-1.55:1; the molar ratio of trimellitic anhydride chloride: the flexible long-chain dianhydride monomer is 1.0-2.5:

1.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The flexible long-chain aromatic diamine monomer is any one or more of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4′-diaminodiphenyl ether, 2,2′-bis[4-(4-aminophenoxy)phenyl]ether, and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane.

5. The preparation method according to any one of claims 1 to 3, characterized in that: The siloxane diamine monomer is at least one of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane or α,ω-diaminoalkane.

6. The preparation method according to any one of claims 1 to 3, characterized in that: The acid binding agent is at least one of triethylamine and N,N-diisopropylethylamine; and the end-capping agent is phthalic anhydride.

7. The preparation method according to any one of claims 1 to 3, characterized in that: The flexible long-chain dianhydride monomer is any one or more of bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 4,4'-diphthalic anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuranyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, and 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride.

8. The preparation method according to any one of claims 1 to 3, characterized in that: The catalyst is at least one of isoquinoline and pyridine; and the water absorbent is acetic anhydride.

9. The preparation method according to any one of claims 1 to 3, characterized in that: The mass of the silicone epoxy resin is 6-10% of the mass of the polyamideimide-polyimide copolymer resin.

10. An adhesive film for temporary packaging of semiconductor elements, characterized in that: The adhesive layer of the adhesive film uses a polyamideimide-polyimide copolymer resin adhesive prepared by the preparation method according to any one of claims 1 to 9.

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