Preparation and application method of low-residue thermal stripping temporary bonding adhesive

Abstract

The invention discloses a preparation and application method of a low-residue thermal stripping temporary bonding adhesive, and relates to the technical field of bonding adhesive preparation, and the preparation method comprises the following steps: S1, adding a solvent into a reaction kettle and stirring, adding modified resin and stirring, adding a stabilizer and stirring, adding polyoxypropylene ether and stirring, and adding a composite initiator and stirring; adding hexadecyl trimethoxy silane, stirring, adding polydimethylsiloxane, and stirring, so as to obtain a glue solution; s2, carrying out pressure filtration on the glue solution, filtering out impurities, and putting the filtered glue solution into a vacuum defoaming kettle to obtain low-residue thermal stripping temporary bonding glue; according to the invention, the composite initiator is added and can accurately trigger fracture of weak bonds in a modified resin molecular chain in a target temperature interval, the initiator system is highly stable in a 300 DEG C high-temperature process, is not decomposed in advance and is not volatilized, ensures stable process performance of an adhesive layer, and meanwhile, the system is of an all-organic structure and is free of solid residues after decomposition; and the residual quantity of the adhesive layer is not increased.

Description

Technical Field

[0001] This invention relates to the field of bonding adhesive preparation technology, and in particular to a method for preparing and applying a low-residue thermally peelable temporary bonding adhesive. Background Technology

[0002] Bonding adhesive is a special adhesive used for microelectronic packaging and chip bonding. Its main function is to firmly bond chips, substrates, or other microelectronic components together. It is widely used in semiconductor manufacturing, LED packaging, MEMS, and other fields, providing not only mechanical fixation but also electrical connections, heat dissipation, or insulation.

[0003] Traditional low-residue thermally peelable temporary bonding adhesives suffer from thermo-oxidative aging and delamination during high-temperature processes. They also exhibit drawbacks such as insufficient cohesion leading to an imbalance between bond strength and ease of peeling. Conventional initiators are prone to premature decomposition at high temperatures and exhibit poor compatibility and uneven dispersion with resins, resulting in incomplete thermal decomposition and low peeling efficiency. Poorly formulated solvent systems can lead to viscosity incompatibility with spin-coating processes and uneven film thickness. Mismatched solvent evaporation rates can cause solvent retention in the adhesive layer, resulting in bubbling at high temperatures. Bubbles are easily generated during adhesive mixing, leading to voids at the bonding interface. Excessively high interfacial energy between the bonding adhesive and the wafer substrate results in poor wettability, easily leaving adhesive residue during peeling. Furthermore, impurities in the raw materials and residues of various additives can easily lead to solid residues and metal ion contamination on the wafer surface. Therefore, this invention provides a method for preparing and applying a low-residue thermally peelable temporary bonding adhesive. Summary of the Invention

[0004] The main objective of this invention is to provide a low-residue thermally release temporary bonding adhesive with high stability and short thermally release time at 380°C, which is applied in a method for preparing and using a low-residue thermally release temporary bonding adhesive.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for preparing a low-residue thermally release temporary bonding adhesive, which includes the following steps: S1. Add the solvent to the reactor and stir. Set the reactor temperature to 80-90℃ and the stirring speed to 600 rpm. Add the modified resin and stir. Set the reactor temperature to 80-90℃ and the stirring speed to 600 rpm. Stir at this constant temperature for 2 hours. Allow the reactor temperature to cool naturally to 40℃. Add the stabilizer and stir. Set the stirring speed to 800 rpm and stir for 30 minutes. Add the polyoxypropylene ether and stir. Set the stirring speed to 800 rpm and stir for 40 minutes. Add the composite initiator and stir. Set the stirring speed to 800 rpm and stir for 20 minutes. Add the hexadecyltrimethoxysilane and stir. Set the stirring speed to 1500 rpm and stir for 20 minutes. Add the polydimethylsiloxane and stir. Set the stirring speed to 600 rpm and stir for 10 minutes to obtain the adhesive solution. S2. Filter the adhesive solution under pressure, setting the filter membrane to a 0.22μm polytetrafluoroethylene filter membrane, the pressure to 0.3-0.5MPa, and filter out impurities. Place the filtered adhesive solution into a vacuum degassing kettle, set the vacuum degree to -0.095 to -0.098MPa, the rotation speed to 200rpm, and degas for 30-40 minutes to obtain a low-residue thermally peelable temporary bonding adhesive. The low-residue thermally peelable temporary bonding adhesive comprises the following raw materials: 35-45 parts solvent, 45-55 parts modified resin, 0.8-1.5 parts polyoxypropylene ether, 1.5-3 parts composite initiator, 0.2-0.6 parts stabilizer, 0.6-1.8 parts hexadecyltrimethoxysilane and 0.04-0.1 parts polydimethylsiloxane.

[0006] The modified resin features a regular linear block copolymer structure with alternating rigid aromatic segments and flexible weak segments (ester / carbonate bonds) covalently linked. The rigid aromatic segments, formed by copolymerizing 4,4'-difluorobenzophenone and hydroquinone, are the core of the resin's 300℃+ temperature resistance. The flexible weak segments are functional nodes capable of selective breakage, lacking autonomous thermal decomposition characteristics and only being triggered by a composite initiator at 190-210℃. This structure is achieved through a one-step in-situ melt nucleophilic substitution copolymerization. Hydroquinone and a self-made weak-bonded bisphenol monomer are compounded in a specific ratio, and after nitrogen purging and salt formation to generate potassium phenolate with consistent activity, a nucleophilic substitution reaction occurs simultaneously with 4,4'-difluorobenzophenone at the copolymerization temperature. This allows the weak segments to be in-situ blocked during the growth of the modified resin backbone. After termination polymerization, multiple purifications, drying, and pulverization, a modified resin with uniformly distributed weak segments is obtained. The entire process involves no subsequent modification steps, and the weak segments are firmly covalently bonded to the backbone.

[0007] Polyoxypropylene ether is an isocyanate-terminated polyoxypropylene ether, semiconductor grade, with 10% NCO content, exhibiting high reactivity with hydroxyl groups; moisture content <0.05%, free isocyanate; it can pre-react with the terminal hydroxyl groups of modified resins, forming a small amount of cross-linked structure inside the adhesive layer, improving the cohesive strength of the adhesive layer and the anti-debonding ability during 300℃ processing, and the degree of cross-linking is controllable, without affecting the thermal decomposition of the adhesive layer due to excessive cross-linking. After decomposition, the cross-linking bonds break into low molecular weight fragments, leaving no solid residue, and it has excellent compatibility with all organic systems.

[0008] Furthermore, the solvent is a mixture of N-methylpyrrolidone and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0009] N-Methylpyrrolidone is semiconductor grade with a purity ≥99.9%, capable of completely dissolving modified resins; moisture content <0.05%, metal ion content <10 ppb, and free of impurities. As the main solvent of the adhesive, it has excellent solubility for modified resins, enabling the preparation of homogeneous adhesives with high solid content. It also has a moderate boiling point, allowing for rapid evaporation during spin coating and pre-curing without residue. It is chemically stable, does not undergo side reactions with any components in the adhesive, and is miscible with the co-solvent propylene glycol methyl ether acetate, which can adjust the viscosity of the adhesive.

[0010] Propylene glycol methyl ether acetate is a semiconductor-grade, colorless, transparent liquid with a viscosity of ≥99.9%, and a low-viscosity co-solvent. With a boiling point of 146℃ and a moderate evaporation rate, it acts as a co-solvent for adhesives, forming a mixed solvent system with N-methylpyrrolidone. This effectively adjusts the viscosity and spin-coating properties of the adhesive, making it suitable for two-step spin-coating processes on 300mm wafers. It produces uniform films with a moderate evaporation rate. During pre-curing, it co-evaporates with N-methylpyrrolidone, leaving no solvent residue and preventing pinholes / voids in the adhesive layer. It exhibits good compatibility with all organic systems and leaves no residue.

[0011] Furthermore, the stabilizer is composed of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:2.

[0012] Furthermore, the preparation of the modified resin includes the following steps: A1. Add diphenyl sulfone and sulfolane to a reaction vessel, add anhydrous potassium carbonate, hydroquinone and bisphenol monomer, mix and stir, set the speed to 300 rpm, introduce nitrogen gas, heat the reaction vessel temperature to 150-160℃, increase the speed to 500 rpm, and keep the temperature constant for 1.5 hours. Add 4,4'-difluorobenzophenone and stir, set the reaction vessel temperature to 200-220℃, set the speed to 800 rpm, and keep the temperature constant for 3.5-4 hours. Allow the reaction vessel temperature to cool naturally to 100℃, add deionized water and stir, set the speed to 400 rpm, and stir for 30 minutes to obtain a mixture. A2. Add the mixture to deionized water and stir at 200-400 rpm for 30-40 minutes. Use vacuum filtration to remove the liquid and obtain crude resin. A3. Wash the crude resin three times with deionized water, then wash it once with isopropanol. Vacuum dry the washed crude resin at a temperature of 120℃ and a vacuum degree of -0.098MPa for 12 hours. Crush the dried crude resin to 80 mesh to obtain the modified resin.

[0013] Further, the weight ratio of diphenyl sulfone, sulfolane, anhydrous potassium carbonate, hydroquinone, bisphenol monomer, 4,4'-difluorobenzophenone and deionized water in A1 is 3.75:0.55:1.08:0.85:0.15:1:4.3; The volume ratio of the mixture to deionized water in A2 is 1:3.

[0014] 4,4'-Difluorobenzophenone is a semiconductor grade product with a purity of ≥99.99%, moisture content of <0.01%, and is a white crystalline powder with no metal ions (<10 ppb). It is suitable for nucleophilic substitution copolymerization of aromatic monomers and can undergo efficient nucleophilic substitution copolymerization with bisphenol monomers. The constructed aromatic ring structure endows the modified resin with ultra-high temperature resistance of 300℃+. The copolymerization reaction has moderate activity, with no excessive polymerization side reactions, ensuring uniform growth of the resin backbone. Furthermore, the monomer purity is high, with no impurities introduced, and it does not affect the low residue characteristics of the subsequent adhesive solution.

[0015] Furthermore, the diphenol monomer is one of hydroxyethyl p-hydroxybenzoate and 4,4'-dihydroxydiphenyl carbonate.

[0016] Hydroxyethyl p-hydroxybenzoate has a purity of ≥99%, moisture content of <0.01%, and is an 80-mesh white powder with metal ions of <50 ppb. It features uncapped dihydroxyl groups, which are the core introducing monomers for the weak ester bonds. The dihydroxyl structure ensures its participation in nucleophilic substitution copolymerization, precisely blocking the ester bonds within the modified resin backbone. This achieves precise thermal decomposition at 210℃ and ensures strong bonding with the modified resin backbone, without affecting the temperature resistance of the 300℃ process.

[0017] 4,4'-Dihydroxydiphenyl carbonate has a purity ≥99%, moisture <0.01%, and is an 80-mesh white flake powder. It contains uncapped bisphenol hydroxyl groups, residual solvent <0.001%, and metal ions <50 ppb. As a dedicated monomer for introducing weak bonds in carbonate bonds, its symmetrical dihydroxyl structure makes its copolymerization activity consistent with hydroquinone. It can be uniformly block-in-the-middle resin backbone, achieving low-temperature thermal decomposition at 190℃, making it suitable for thermosensitive wafer processes at 300℃+. No harmful byproducts are produced after carbonate bond breakage, the decomposition fragments are easily volatile, and it has good compatibility with all-organic adhesive systems, without affecting the adhesive layer bonding strength.

[0018] Furthermore, the composite initiator is composed of an initiator and a carboxyl-modified azobisisobutyronitrile mixed in a mass ratio of 17:8.

[0019] The composite initiator undergoes a quadruple modification design, including core-shell coating, complexation modification, grain boundary anchoring, and chemical protection by a composite thermal stabilizer. This design completely alters the bulk thermal stability characteristics of the initiator. Furthermore, the high stability at 300℃ is a limiting requirement for short-term high-temperature semiconductor processes, not for long-term constant-temperature stability at 300℃. The modified initiation system achieves no premature decomposition or volatilization at 300℃, while maintaining its free radical release function at the target temperature of 190-210℃.

[0020] Carboxyl-modified azobisisobutyronitrile (AIBN) is a semiconductor-grade white powder with a purity of not less than 99%. It is used after being rinsed with anhydrous ethanol and dried. The moisture content is less than 0.01%. The decomposition temperature is 200 degrees Celsius. The carboxyl groups in the molecule are not capped. As a synergistic co-initiator of the composite initiator, the carboxyl groups can be precisely anchored in the grain boundary region of the modified resin. They decompose first and trigger the cracking of weak bonds at the grain boundary. They form a grain boundary-intragranular global initiation with the main initiator, which solves the problem of lagging initiation in the grain boundary of a single initiator. The decomposition rate is slow, which can regulate the overall initiation rhythm, avoid the instantaneous excessive quenching of free radicals, improve the uniformity of decomposition of the adhesive layer, and leave no solid residue after decomposition.

[0021] Further, the preparation of the initiator includes the following steps: mixing and stirring tert-butyl peroxide and melamine resin micro powder at a speed of 300 rpm for 5 minutes, adding carboxyl-modified polydimethylsiloxane and stirring at a speed of 500 rpm for 8 minutes, adding triethylborane-triethanolamine complex and stirring at a speed of 400 rpm for 5 minutes to obtain the initiator.

[0022] Furthermore, the mass ratio of tert-butyl peroxide, melamine resin micro powder, carboxyl-modified polydimethylsiloxane, and triethylborane-triethanolamine complex is 70:15:10:8.

[0023] tert-butyl peroxide is a semiconductor-grade powder with a purity of ≥99.5%, an 80-mesh pulverization, a moisture content of <0.01%, and a decomposition temperature of 208℃. As the core initiator in a three-material composite initiator, it has a high free radical yield and exhibits exclusive selectivity for the ester / carbonate bond cleavage of the modified resin backbone. Its initiation efficiency is far higher than that of conventional peroxides. After modification with three materials, it forms an ultra-thin, heat-resistant coating structure. It does not decompose or volatilize prematurely during the 300℃ process, has a weight loss of <0.8%, and leaves no solid residue after decomposition. It does not quench the free radicals of the co-initiator, thus achieving synergistic initiation and enhanced efficiency.

[0024] The melamine resin micro powder is semiconductor grade, with a particle size of 1-3μm. It is sieved through a 0.8μm sieve to remove agglomerates. It is a white powder that does not decompose after being kept at 300℃ for 2 hours. The moisture content is <0.01%. It can form an ultra-thin, non-sealed shell on the surface of tert-butyl benzoate through physical adsorption. This shell not only blocks the thermo-oxidative erosion at 300℃ and prevents premature decomposition of tert-butyl benzoate, but also, due to its porous structure, does not affect the release of free radicals during the decomposition of tert-butyl benzoate. Furthermore, it is a completely organic material, leaving no solid residue after decomposition. It has good compatibility with modified resins and will not cause the adhesive to agglomerate.

[0025] The triethylborane-triethanolamine complex is a semiconductor-grade compound with a complexation degree of 99%. It is a stable liquid at room temperature and undergoes low-temperature decomposition at 190-200℃, releasing triethylborane free radicals. It exhibits no oxidative degradation and has a moisture content of <0.01%. Its complex structure remains highly stable during the 300℃ process without premature decomposition or activation. At 190-200℃, it precisely decomposes to release borane free radicals, which initially trigger the micro-cracking of weak bonds at the PEKK grain boundaries, providing a diffusion channel for tert-butyl peroxide free radicals. This achieves a relay initiation process of slow low-temperature triggering and rapid high-temperature initiation. Furthermore, the borane free radicals and the tert-butyl peroxide peroxide free radicals do not undergo quenching, resulting in a free radical synergistic effect that enhances the overall initiation efficiency.

[0026] Carboxyl-modified polydimethylsiloxane is semiconductor grade, a viscous liquid at room temperature, with a solid content of 100%, active carboxyl groups at the molecular end groups, and a moisture content of less than 0.01%.

[0027] Secondly, this invention provides a method for applying a low-residue thermally peelable temporary bonding adhesive. The method involves: first, ultrasonically cleaning the wafer and carrier plate to be bonded with acetone and anhydrous ethanol, then drying and removing impurities for later use; next, dissolving and preparing the bonding adhesive solution, followed by vacuum degassing; and then applying a 5-20 μm uniform adhesive layer to the carrier plate surface using a two-step spin-coating process. This layer is then pre-cured in stages at 80°C and 150°C to remove solvent and form a dense dry adhesive film. Finally, the adhesive-coated carrier plate and the cleaned wafer are placed in a vacuum bonding machine at 180-200°C and 0.3-0.5 MPa. Under vacuum pressure conditions, temporary bonding is completed. The bonded composite system can be directly adapted to high-temperature semiconductor processes at 300°C and below. After the process is completed, the wafer is thermally peeled off with precise temperature control according to the adhesive type. Ester bond adhesive layers are heated at a constant temperature of 210°C, and carbonate bond adhesive layers are heated at a constant temperature of 190°C. After peeling, the wafer and the substrate can be separated without adhesion. Finally, the peeled wafer is gently wiped with a mixture of acetone and isopropanol or cleaned with low-power ultrasonic cleaning, then rinsed with anhydrous ethanol and dried with high-purity nitrogen to meet the cleanliness requirements of subsequent semiconductor processes. The peeled substrate can be reused after cleaning.

[0028] The present invention has the following beneficial effects: 1. In this invention, a modified resin is added, which provides the adhesive layer with ultra-high temperature resistance of over 300 degrees Celsius, ensuring that the adhesive layer does not debond or decompose during the high-temperature semiconductor process. At the same time, it gives the adhesive layer appropriate bonding strength, ensuring the firmness of the wafer bonding process. The ester bonds or carbonate bonds in its molecular chain are the core of achieving precise thermal peeling of the adhesive layer. After decomposition, it forms low-molecular-weight volatile fragments with no solid residue, fundamentally ensuring the low-residue characteristics of the bonding adhesive.

[0029] 2. In this invention, a composite initiator is added, which can precisely trigger the breaking of weak bonds in the modified resin molecular chain within the target temperature range. The initiator system is highly stable in the 300-degree Celsius high-temperature process, with no premature decomposition or volatilization, ensuring the stability of the adhesive layer process performance. At the same time, the system is a fully organic structure, leaving no solid residue after decomposition, which will not increase the amount of adhesive layer residue. It can also achieve uniform decomposition throughout the grain boundaries and grains of the adhesive layer, avoiding localized adhesive residue after peeling.

[0030] 3. In this invention, a solvent is added, which can evaporate rapidly during the pre-curing stage of the adhesive layer, leaving no solvent residue. This avoids problems such as bubbles, bulging, and debonding caused by residual solvent evaporation during the 300-degree Celsius high-temperature process, ensuring the high-temperature stability of the adhesive layer. It also has excellent compatibility with the all-organic adhesive system, with no layering or precipitation, and will not introduce any solid residue into the adhesive layer. It does not affect the subsequent precise thermal peeling and low-residue core characteristics of the bonding adhesive, and can also jointly improve the storage stability of the adhesive and the overall process adaptability. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that all raw materials used in the following experiments are commercially available.

[0033] Example 1: Preparation of a low-residue thermally release temporary bonding adhesive. The preparation of the low-residue thermally release temporary bonding adhesive includes the following steps: S1. Add the solvent to the reactor and stir. Set the reactor temperature to 80℃ and the stirring speed to 600 rpm. Add the modified resin and stir. Set the reactor temperature to 80℃ and the stirring speed to 600 rpm. Stir at this constant temperature for 2 hours. Allow the reactor temperature to cool naturally to 40℃. Add the stabilizer and stir. Set the stirring speed to 800 rpm and stir for 30 minutes. Add the polyoxypropylene ether and stir. Set the stirring speed to 800 rpm and stir for 40 minutes. Add the composite initiator and stir. Set the stirring speed to 800 rpm and stir for 20 minutes. Add the hexadecyltrimethoxysilane and stir. Set the stirring speed to 1500 rpm and stir for 20 minutes. Add the polydimethylsiloxane and stir. Set the stirring speed to 600 rpm and stir for 10 minutes to obtain the adhesive solution. S2. The adhesive solution is pressurized and filtered. The filter membrane is set to 0.22μm polytetrafluoroethylene filter membrane and the pressure is 0.3MPa. Impurities are filtered out. The filtered adhesive solution is placed into a vacuum degassing kettle, the vacuum degree is set to -0.095MPa, the rotation speed is 200rpm, and degassing is performed for 40 minutes to obtain a low residual thermally peelable temporary bonding adhesive. The low-residue thermally peelable temporary bonding adhesive comprises the following raw materials: 35 parts solvent, 45 parts modified resin, 0.8 parts polyoxypropylene ether, 1.5 parts composite initiator, 0.2 parts stabilizer, 0.6 parts hexadecyltrimethoxysilane and 0.04 parts polydimethylsiloxane.

[0034] The solvent is a mixture of N-methylpyrrolidone and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0035] The stabilizer is a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:2.

[0036] The preparation of modified resins includes the following steps: A1. Add diphenyl sulfone and sulfolane to a reaction vessel, add anhydrous potassium carbonate, hydroquinone and bisphenol monomer, mix and stir, set the speed to 300 rpm, introduce nitrogen gas, heat the reaction vessel temperature to 150℃, increase the speed to 500 rpm, and keep the temperature constant for 1.5 hours. Add 4,4'-difluorobenzophenone and stir, set the reaction vessel temperature to 200℃, the speed to 800 rpm, and keep the temperature constant for 4 hours. Let the reaction vessel temperature cool naturally to 100℃, add deionized water and stir, set the speed to 400 rpm, and stir for 30 minutes to obtain a mixture. A2. Add the mixture to deionized water and stir at 200 rpm for 40 minutes. Use vacuum filtration to remove the liquid and obtain crude resin. A3. Wash the crude resin three times with deionized water, then wash it once with isopropanol. Vacuum dry the washed crude resin at a temperature of 120℃ and a vacuum degree of -0.098MPa for 12 hours. Crush the dried crude resin to 80 mesh to obtain the modified resin.

[0037] The weight ratio of diphenyl sulfone, sulfolane, anhydrous potassium carbonate, hydroquinone, bisphenol monomer, 4,4'-difluorobenzophenone and deionized water in A1 is 3.75:0.55:1.08:0.85:0.15:1:4.3. The volume ratio of the mixture to deionized water in A2 is 1:3.

[0038] The diphenol monomer is hydroxyethyl p-hydroxybenzoate.

[0039] The composite initiator is composed of an initiator and a carboxyl-modified azobisisobutyronitrile mixed in a mass ratio of 17:8.

[0040] The preparation of the initiator includes the following steps: mixing and stirring tert-butyl peroxide and melamine resin powder at 300 rpm for 5 minutes, adding carboxyl-modified polydimethylsiloxane and stirring at 500 rpm for 8 minutes, adding triethylborane-triethanolamine complex and stirring at 400 rpm for 5 minutes to obtain the initiator.

[0041] The mass ratio of tert-butyl peroxide, melamine resin micro powder, carboxyl-modified polydimethylsiloxane, and triethylborane-triethanolamine complex is 70:15:10:8.

[0042] A method for applying a low-residue thermally peelable temporary bonding adhesive is disclosed. The method involves first ultrasonically cleaning the wafer and carrier substrate with acetone and anhydrous ethanol, then drying to remove impurities. Next, the bonding adhesive is dissolved and prepared, then vacuum degassed. A two-step spin-coating process is used to coat the carrier substrate surface, forming a uniform 5μm adhesive layer. This layer is then pre-cured at 80℃ and 150℃ in stages to remove solvent and form a dense dry adhesive film. Finally, the adhesive-coated carrier substrate and the cleaned wafer are placed in a vacuum bonding machine, and the temporary bond is completed under vacuum pressing at 180℃ and 0.3MPa. The bonded composite system can be directly adapted to high-temperature semiconductor processes at 300℃ and below. After the process is completed, the wafer can be thermally peeled off with precise temperature control according to the adhesive type. The ester bond adhesive layer is heated at a constant temperature of 210℃ and the carbonate bond adhesive layer is heated at a constant temperature of 190℃. After that, the wafer and the substrate can be separated without adhesion by gently peeling off. Finally, the peeled wafer is gently wiped with a mixture of acetone and isopropanol or cleaned with low-power ultrasonic cleaning, then rinsed with anhydrous ethanol and dried with high-purity nitrogen. This can meet the cleanliness requirements of subsequent semiconductor processes. The peeled substrate can be reused after cleaning.

[0043] Example 2: Preparation of a low-residue thermally release temporary bonding adhesive. The preparation of the low-residue thermally release temporary bonding adhesive includes the following steps: S1. Add the solvent to the reactor and stir. Set the reactor temperature to 85℃ and the stirring speed to 600 rpm. Add the modified resin and stir. Set the reactor temperature to 85℃ and the stirring speed to 600 rpm. Stir at this constant temperature for 2 hours. Allow the reactor temperature to cool naturally to 40℃. Add the stabilizer and stir. Set the stirring speed to 800 rpm and stir for 30 minutes. Add the polyoxypropylene ether and stir. Set the stirring speed to 800 rpm and stir for 40 minutes. Add the composite initiator and stir. Set the stirring speed to 800 rpm and stir for 20 minutes. Add the hexadecyltrimethoxysilane and stir. Set the stirring speed to 1500 rpm and stir for 20 minutes. Add the polydimethylsiloxane and stir. Set the stirring speed to 600 rpm and stir for 10 minutes to obtain the adhesive solution. S2. The adhesive solution is pressurized and filtered. The filter membrane is set to 0.22μm polytetrafluoroethylene filter membrane and the pressure is 0.4MPa. Impurities are filtered out. The filtered adhesive solution is placed into a vacuum degassing kettle, the vacuum degree is set to -0.096MPa, the rotation speed is 200rpm, and degassing is performed for 35 minutes to obtain a low residual thermally peelable temporary bonding adhesive. The low-residue thermally peelable temporary bonding adhesive comprises the following raw materials: 40 parts solvent, 50 parts modified resin, 1.15 parts polyoxypropylene ether, 2.25 parts composite initiator, 0.4 parts stabilizer, 1.2 parts hexadecyltrimethoxysilane and 0.07 parts polydimethylsiloxane.

[0044] The solvent is a mixture of N-methylpyrrolidone and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0045] The stabilizer is a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:2.

[0046] The preparation of modified resins includes the following steps: A1. Add diphenyl sulfone and sulfolane to a reaction vessel, add anhydrous potassium carbonate, hydroquinone and bisphenol monomer, mix and stir, set the speed to 300 rpm, introduce nitrogen gas, heat the reaction vessel temperature to 155℃, increase the speed to 500 rpm, and keep the temperature constant for 1.5 hours. Add 4,4'-difluorobenzophenone and stir, set the reaction vessel temperature to 210℃, set the speed to 800 rpm, and keep the temperature constant for 3.7 hours. Allow the reaction vessel temperature to cool naturally to 100℃, add deionized water and stir, set the speed to 400 rpm, and stir for 30 minutes to obtain a mixture. A2. Add the mixture to deionized water and stir. Set the speed to 300 rpm and stir for 35 minutes. Use vacuum filtration to remove the liquid and obtain crude resin. A3. Wash the crude resin three times with deionized water, then wash it once with isopropanol. Vacuum dry the washed crude resin at a temperature of 120℃ and a vacuum degree of -0.098MPa for 12 hours. Crush the dried crude resin to 80 mesh to obtain the modified resin.

[0047] The weight ratio of diphenyl sulfone, sulfolane, anhydrous potassium carbonate, hydroquinone, bisphenol monomer, 4,4'-difluorobenzophenone and deionized water in A1 is 3.75:0.55:1.08:0.85:0.15:1:4.3. The volume ratio of the mixture to deionized water in A2 is 1:3.

[0048] The bisphenol monomer is 4,4'-dihydroxydiphenyl carbonate.

[0049] The composite initiator is composed of an initiator and a carboxyl-modified azobisisobutyronitrile mixed in a mass ratio of 17:8.

[0050] The preparation of the initiator includes the following steps: mixing and stirring tert-butyl peroxide and melamine resin powder at 300 rpm for 5 minutes, adding carboxyl-modified polydimethylsiloxane and stirring at 500 rpm for 8 minutes, adding triethylborane-triethanolamine complex and stirring at 400 rpm for 5 minutes to obtain the initiator.

[0051] The mass ratio of tert-butyl peroxide, melamine resin micro powder, carboxyl-modified polydimethylsiloxane, and triethylborane-triethanolamine complex is 70:15:10:8.

[0052] A method for applying a low-residue thermally peelable temporary bonding adhesive is disclosed. The method involves first ultrasonically cleaning the wafer and carrier substrate with acetone and anhydrous ethanol, then drying to remove impurities. Next, the bonding adhesive is dissolved and prepared, then vacuum degassed. A two-step spin-coating process is used to coat the carrier substrate surface, forming a uniform 12μm adhesive layer. This layer is then pre-cured at 80℃ and 150℃ in stages to remove solvent and form a dense dry adhesive film. Finally, the adhesive-coated carrier substrate and the cleaned wafer are placed in a vacuum bonding machine, and vacuum bonding is performed at 190℃ and 0.4MPa to complete the temporary bonding process. The bonded composite system can be directly adapted to high-temperature semiconductor processes at 300℃ and below. After the process is completed, the wafer is precisely thermally peeled off according to the adhesive type with precise temperature control. The ester bond adhesive layer is heated at a constant temperature of 210℃ and the carbonate bond adhesive layer is heated at a constant temperature of 190℃. After peeling, the wafer and the substrate can be separated without adhesion. Finally, the peeled wafer is gently wiped with a mixture of acetone and isopropanol or cleaned with low-power ultrasonic cleaning, then rinsed with anhydrous ethanol and dried with high-purity nitrogen. This meets the cleanliness requirements of subsequent semiconductor processes. The peeled substrate can be reused after cleaning.

[0053] Example 3: Preparation of a low-residue thermally release temporary bonding adhesive. The preparation of the low-residue thermally release temporary bonding adhesive includes the following steps: S1. Add the solvent to the reactor and stir. Set the reactor temperature to 90℃ and the stirring speed to 600 rpm. Add the modified resin and stir. Set the reactor temperature to 90℃ and the stirring speed to 600 rpm. Stir at this constant temperature for 2 hours. Allow the reactor temperature to cool naturally to 40℃. Add the stabilizer and stir. Set the stirring speed to 800 rpm and stir for 30 minutes. Add the polyoxypropylene ether and stir. Set the stirring speed to 800 rpm and stir for 40 minutes. Add the composite initiator and stir. Set the stirring speed to 800 rpm and stir for 20 minutes. Add the hexadecyltrimethoxysilane and stir. Set the stirring speed to 1500 rpm and stir for 20 minutes. Add the polydimethylsiloxane and stir. Set the stirring speed to 600 rpm and stir for 10 minutes to obtain the adhesive solution. S2. Pressurize and filter the adhesive solution, setting the filter membrane to 0.22μm polytetrafluoroethylene filter membrane, pressure 0.5MPa, filter out impurities, put the filtered adhesive solution into a vacuum degassing kettle, set the vacuum degree to -0.098MPa, speed 200rpm, degas for 30 minutes to obtain low residual thermal peeling temporary bonding adhesive. The low-residue thermally peelable temporary bonding adhesive comprises the following raw materials: 45 parts solvent, 55 parts modified resin, 1.5 parts polyoxypropylene ether, 3 parts composite initiator, 0.6 parts stabilizer, 1.8 parts hexadecyltrimethoxysilane and 0.1 parts polydimethylsiloxane.

[0054] The solvent is a mixture of N-methylpyrrolidone and propylene glycol methyl ether acetate in a mass ratio of 7:3.

[0055] The stabilizer is a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:2.

[0056] The preparation of modified resins includes the following steps: A1. Add diphenyl sulfone and sulfolane to a reaction vessel, add anhydrous potassium carbonate, hydroquinone and bisphenol monomer, mix and stir, set the speed to 300 rpm, introduce nitrogen gas, heat the reaction vessel temperature to 160℃, increase the speed to 500 rpm, and keep the temperature constant for 1.5 hours. Add 4,4'-difluorobenzophenone and stir, set the reaction vessel temperature to 220℃, the speed to 800 rpm, and keep the temperature constant for 3.5 hours. Let the reaction vessel temperature cool naturally to 100℃, add deionized water and stir, set the speed to 400 rpm, and stir for 30 minutes to obtain a mixture. A2. Add the mixture to deionized water and stir at 400 rpm for 30 minutes. Use vacuum filtration to remove the liquid and obtain crude resin. A3. Wash the crude resin three times with deionized water, then wash it once with isopropanol. Vacuum dry the washed crude resin at a temperature of 120℃ and a vacuum degree of -0.098MPa for 12 hours. Crush the dried crude resin to 80 mesh to obtain the modified resin.

[0057] The weight ratio of diphenyl sulfone, sulfolane, anhydrous potassium carbonate, hydroquinone, bisphenol monomer, 4,4'-difluorobenzophenone and deionized water in A1 is 3.75:0.55:1.08:0.85:0.15:1:4.3. The volume ratio of the mixture to deionized water in A2 is 1:3.

[0058] The diphenol monomer is hydroxyethyl p-hydroxybenzoate.

[0059] The composite initiator is composed of an initiator and a carboxyl-modified azobisisobutyronitrile mixed in a mass ratio of 17:8.

[0060] The preparation of the initiator includes the following steps: mixing and stirring tert-butyl peroxide and melamine resin powder at 300 rpm for 5 minutes, adding carboxyl-modified polydimethylsiloxane and stirring at 500 rpm for 8 minutes, adding triethylborane-triethanolamine complex and stirring at 400 rpm for 5 minutes to obtain the initiator.

[0061] The mass ratio of tert-butyl peroxide, melamine resin micro powder, carboxyl-modified polydimethylsiloxane, and triethylborane-triethanolamine complex is 70:15:10:8.

[0062] A method for applying a low-residue thermally peelable temporary bonding adhesive is disclosed. The method involves first ultrasonically cleaning the wafer and carrier substrate with acetone and anhydrous ethanol, then drying to remove impurities. Next, the bonding adhesive is dissolved and prepared, then vacuum degassed. A two-step spin-coating process is used to coat the carrier substrate surface, forming a uniform 20μm adhesive layer. This layer is then pre-cured at 80℃ and 150℃ in stages to remove solvent and form a dense dry adhesive film. Finally, the adhesive-coated carrier substrate and the cleaned wafer are placed in a vacuum bonding machine and vacuum-pressed at 200℃ and 0.5MPa to complete the temporary bonding process. The bonded composite system can be directly adapted to high-temperature semiconductor processes at 300℃ and below. After the process is completed, the wafer is precisely thermally peeled off according to the adhesive type with precise temperature control. The ester bond adhesive layer is heated at a constant temperature of 210℃ and the carbonate bond adhesive layer is heated at a constant temperature of 190℃. After peeling, the wafer and the substrate can be separated without adhesion. Finally, the peeled wafer is gently wiped with a mixture of acetone and isopropanol or cleaned with low-power ultrasonic cleaning, then rinsed with anhydrous ethanol and dried with high-purity nitrogen. This meets the cleanliness requirements of subsequent semiconductor processes. The peeled substrate can be reused after cleaning.

[0063] Comparative Example 1: The difference between this comparative example and Example 1 is that: In this comparative example, only propylene glycol methyl ether acetate was used as the solvent.

[0064] Comparative Example 2: The difference between this comparative example and Example 1 is that: In this comparative example, only carboxyl-modified azobisisobutyronitrile was used as the composite initiator.

[0065] Comparative Example 3 differs from Example 1 in that: In this comparative example, the modified resin was replaced with polyaryletherketone resin.

[0066] Performance testing: The low-residue thermally peelable temporary bonding adhesives prepared in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were tested.

[0067] Performance testing: The relevant properties of the samples prepared and applied by the low-residue thermally peelable temporary bonding adhesive provided in Examples 1-3 and Comparative Examples 1-3 were tested respectively. The test data are recorded in Table 1 below: Based on the above data, the following conclusions can be drawn: Among them, the viscosity change rate of a low-residue thermally peelable temporary bonding adhesive prepared by Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3 in GB / T13354-1992 was tested after 6 months of sealed storage at 25°C. The heat peeling time at 380°C of a low-residue thermally peelable temporary bond prepared according to the test methods in GB / T11357-2008 (Examples 1, 2, 3, Comparative Examples 1, 2, and 3) was tested. The thermal cycling stability shear strength retention rate of a low-residue thermally peelable temporary bond prepared according to the test methods in GB / T2423.22-2012, namely Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3, was tested.

[0068] Through the above demonstrations, the present invention is significantly superior to the control group in terms of viscosity change rate after 6 months of sealed storage at 25℃, hot peeling time at 380℃, and shear strength retention rate under thermal cycling stability, thus verifying the advanced nature and rationality of the preparation process.

[0069] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a low-residue thermally peelable temporary bonding adhesive, characterized in that, The preparation of the low-residue thermally peelable temporary bonding adhesive includes the following steps: S1. Add solvent to reaction vessel and stir, add modified resin and stir, add stabilizer and stir, add polyoxypropylene ether and stir, add composite initiator and stir, add hexadecyltrimethoxysilane and stir, add polydimethylsiloxane and stir to obtain adhesive solution; S2. Pressurize and filter the adhesive solution to remove impurities. Place the filtered adhesive solution into a vacuum degassing kettle to obtain a low-residue thermally peelable temporary bonding adhesive. The low-residue thermally peelable temporary bonding adhesive comprises the following raw materials: 35-45 parts solvent, 45-55 parts modified resin, 0.8-1.5 parts polyoxypropylene ether, 1.5-3 parts composite initiator, 0.2-0.6 parts stabilizer, 0.6-1.8 parts hexadecyltrimethoxysilane and 0.04-0.1 parts polydimethylsiloxane.

2. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 1, characterized in that, The solvent is a mixture of N-methylpyrrolidone and propylene glycol methyl ether acetate in a mass ratio of 7:

3.

3. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 1, characterized in that, The stabilizer is composed of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite in a mass ratio of 1:

2.

4. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 1, characterized in that, The preparation of the modified resin includes the following steps: A1. Add diphenyl sulfone and sulfolane to a reaction vessel, add anhydrous potassium carbonate, hydroquinone and bisphenol monomer, mix and stir, purge with nitrogen, add 4,4'-difluorobenzophenone and stir, add deionized water and stir to obtain a mixture; A2. Add the mixture to deionized water and stir. Use vacuum filtration to remove the liquid and obtain crude resin. A3. Wash the crude resin with deionized water, then wash it with isopropanol, vacuum dry the washed crude resin, and pulverize the dried crude resin to obtain the modified resin.

5. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 4, characterized in that, The weight ratio of diphenyl sulfone, sulfolane, anhydrous potassium carbonate, hydroquinone, bisphenol monomer, 4,4'-difluorobenzophenone and deionized water in A1 is 3.75:0.55:1.08:0.85:0.15:1:4.

3. The volume ratio of the mixture to deionized water in A2 is 1:

3.

6. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 4, characterized in that, The diphenol monomer is one of hydroxyethyl p-hydroxybenzoate and 4,4'-dihydroxydiphenyl carbonate.

7. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 1, characterized in that, The composite initiator is composed of an initiator and a carboxyl-modified azobisisobutyronitrile mixed in a mass ratio of 17:

8.

8. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 7, characterized in that, The preparation of the initiator includes the following steps: mixing and stirring tert-butyl peroxide and melamine resin micro powder, adding carboxyl-modified polydimethylsiloxane and stirring, adding triethylborane-triethanolamine complex and stirring to obtain the initiator.

9. The preparation of the low-residue thermally peelable temporary bonding adhesive according to claim 8, characterized in that, The mass ratio of tert-butyl peroxide, melamine resin micro powder, carboxyl-modified polydimethylsiloxane, and triethylborane-triethanolamine complex is 70:15:10:

8.

10. A method for applying the low-residue thermally peelable temporary bonding adhesive prepared according to any one of claims 1-9, characterized in that, The application method of the low-residue thermally peelable temporary bonding adhesive is as follows: First, the wafer to be bonded and the carrier are ultrasonically cleaned with acetone and anhydrous ethanol and dried to remove impurities for later use. Then, the bonding adhesive is dissolved and prepared, and vacuum degassed. A two-step spin coating process is used to coat the surface of the carrier to form an adhesive layer. After pre-curing to remove solvent, a dense dry adhesive film is formed. Subsequently, the adhesive-coated carrier and the clean wafer are placed in a vacuum bonding machine to complete the temporary bonding. The composite system after bonding can be directly adapted to the high-temperature semiconductor process. After the process is completed, the wafer is thermally peeled off with precise temperature control according to the adhesive type. The ester bond type adhesive layer is heated at a constant temperature of 210°C, and the carbonate bond type adhesive layer is heated at a constant temperature of 190°C. After the adhesive is gently peeled off, the wafer and the carrier can be separated without adhesion. Finally, the peeled wafer is gently wiped with a mixed solution of acetone and isopropanol or ultrasonically cleaned with low power, then rinsed with anhydrous ethanol and dried with high-purity nitrogen to meet the cleanliness requirements of subsequent semiconductor processes. The peeled carrier can be reused after cleaning.

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