CN-121343546-B - Temporary bonding adhesive and application thereof

Abstract

The invention discloses temporary bonding adhesive and application thereof. The temporary bonding adhesive comprises polyimide, wherein the polyimide comprises a large conjugated unit, the conjugated atom number of the large conjugated unit is more than or equal to 40, the large conjugated unit comprises at least one of diphenyl ether group, fluorenyl group or indan structural unit, and the polyimide also comprises at least one of benzotriazole group and nitro group. According to the invention, through the improvement on the polyimide structure, the temporary bonding adhesive is used in wafer processing, so that the absorbance of the temporary bonding adhesive at the 355nm of the target bonding-off wavelength is obviously increased, the threshold bonding-off energy is obviously reduced, the risks of warping and cracking of the wafer or failure of a surface device are hopefully reduced, and the service life of the laser and the bonding-off efficiency are improved.

Inventors

• ZHOU MING
• JIA BAOQUAN
• WANG JIAN
• Qiu Sili

Assignees

• 深圳好电科技有限公司

Dates

Publication Date

20260512

Application Date

20251218

Claims (8)

1. 1. The temporary bonding adhesive is characterized by comprising polyimide, wherein the polyimide comprises a large conjugated unit, the conjugated atom number of the large conjugated unit is more than or equal to 40, the polyimide is obtained by reacting a raw material composition comprising diamine and dianhydride, the diamine is selected from the group consisting of 9, 9-bis (4-aminophenyl) fluorene and 4,4 '-diaminobiphenyl-2, 2' -dicarboxylic acid or the group consisting of 2-nitrop-phenylenediamine, 9-bis (4-aminophenyl) fluorene and 4,4 '-diaminobiphenyl-2, 2' -dicarboxylic acid, the product obtained by esterification reaction of 4,4 '-diaminobiphenyl-2, 2' -dicarboxylic acid and 2- (2 '-hydroxy-5' -methylphenyl) benzotriazole is reacted with dianhydride, and the dianhydride is selected from the group consisting of 2,3, 3 ', 4' -diphenyl ether tetracarboxylic dianhydride.
2. 2. The temporary bonding adhesive according to claim 1, wherein the molar ratio of the diamine to the dianhydride is (0.95-1.05): 1.
3. 3. The temporary bonding glue according to claim 1, wherein the absorption coefficient of the temporary bonding glue at the wavelength of 355nm is not less than 1.6L/(g.cm).
4. 4. The temporary bonding adhesive according to claim 3, wherein the absorption coefficient of the temporary bonding adhesive at a wavelength of 355nm is 1.707-2.671 l/(g cm).
5. 5. The temporary bonding adhesive according to claim 4, wherein when the carrier plate is an ultraviolet quartz molten glass with a thickness of 490-510 microns, the temporary bonding adhesive has a threshold debonding energy of <300mJ/cm 2 under an ultraviolet laser with a wavelength of 355 nm.
6. 6. The temporary bonding adhesive according to claim 1, wherein the mass fraction of the polyimide in the temporary bonding adhesive is 10-40 wt%.
7. 7. The temporary bonding adhesive according to claim 1, further comprising a leveling agent, wherein the leveling agent is an organosilicon leveling agent or a fluorocarbon leveling agent, and the leveling agent is 0.1-1wt%.
8. 8. The use of a temporary bonding glue according to any one of claims 1 to 7, wherein the temporary bonding glue is used in wafer processing to temporarily bond a wafer to a carrier.

Description

Temporary bonding adhesive and application thereof Technical Field The invention belongs to the technical field of wafer processing materials, and particularly relates to temporary bonding adhesive and application thereof. Background With the rapid development of the semiconductor industry, integrated circuit chips are continuously evolving toward miniaturization, multifunctionality and intelligence. Advanced packaging technology is becoming the core of industry development as a key force to drive this trend. In advanced packaging processes, such as three-dimensional stacked packages, fan-Out wafer level packages (Fan-Out WAFER LEVEL PACKAGING, FOWLP), 2.5D/3D packages under through silicon via (Through Silicon Via, TSV) technology, etc., the demand for ultra-thin wafers is becoming increasingly significant. In the wafer processing process, in order to meet the heat dissipation and packaging requirements of the chip, it is often necessary to thin the wafer to a specific thickness. However, the ultrathin wafer has the characteristics of flexibility, fragility, easiness in warping and bending and the like, and the wafer is extremely easy to crack when being directly processed, so that the yield, the processing precision and the packaging precision of chip manufacturing are seriously affected. To solve this problem, temporary bonding techniques have been developed. The temporary bonding technology temporarily bonds the device wafer and a rigid carrier (such as silicon, glass or sapphire substrate) together by using temporary bonding glue, so as to provide enough mechanical support for the ultrathin wafer and ensure that the ultrathin wafer can be smoothly processed in the subsequent processes of photoetching, etching, passivation, electroplating, reflow soldering and the like. After all the processes are completed, the carrier wafer and the device wafer are separated by a specific de-bonding mode, so that the complete ultrathin device wafer is obtained. In a plurality of bonding-releasing modes, ultraviolet laser bonding-releasing has remarkable advantages in processing of large-size ultrathin wafers due to the characteristics of high efficiency, room-temperature operation, low stress and the like, and becomes a research hot spot and development trend in the current temporary bonding technical field. Polyimide material is ideal ultraviolet laser bonding temporary bonding adhesive material because of excellent thermal stability, chemical stability, mechanical property, good film forming property and good ultraviolet absorption capability. However, the ultraviolet absorbance of the existing polyimide temporary bonding adhesive is low, the threshold de-bonding energy exceeds 400mJ/cm 2, and the high-energy laser and the thermal effect thereof can lead to wafer warpage, crack or failure of surface devices (such as metal wiring and dielectric layers) and also reduce the service life of the laser. In addition, the high-energy laser needs to avoid the local energy from being too high through the low scanning speed, so that the bonding-off efficiency is lower. Disclosure of Invention In order to solve the problem of low bonding release efficiency of the conventional polyimide temporary bonding adhesive, the invention provides a temporary bonding adhesive and application thereof, which are used for improving bonding release efficiency. The aim of the invention is realized by the following technical scheme. In a first aspect, the invention provides a temporary bonding adhesive, which comprises polyimide, wherein the polyimide comprises a large conjugated unit, the conjugated atomic number of the large conjugated unit is more than or equal to 40, the large conjugated unit comprises at least one of diphenyl ether group, fluorenyl group or indan structural unit, and the polyimide also comprises at least one of benzotriazole group and nitro group. Further, the polyimide is continuously conjugated. Further, the polyimide is obtained by reacting a raw material composition comprising diamine and dianhydride, wherein the diamine contains at least one of nitro and benzotriazole groups. Further, the molar ratio of the diamine to the dianhydride is (0.95-1.05): 1. Further, the light absorption coefficient of the temporary bonding adhesive at the wavelength of 355nm is more than or equal to 1.6L/(g.cm), and the light absorption coefficient is preferably 1.707-2.671L/(g.cm). Further, when the carrier plate is ultraviolet quartz fused glass with the thickness of 490-510 microns, the threshold debonding energy of the temporary bonding adhesive under an ultraviolet laser with the wavelength of 355nm is less than 300mJ/cm 2. Preferably, when the carrier plate is ultraviolet quartz fused glass with the thickness of 490-510 microns, the threshold debonding energy of the temporary bonding adhesive under an ultraviolet laser with the wavelength of 355nm is 100-230 mJ/cm 2. Further, the mass fraction of polyimide in the temporary bonding adh