UV Tape Peeling Method for Damage-Free Wafer Processing
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Summary
Problems
In semiconductor device fabrication, the peeling of protective tapes from device wafers can damage microscopic structures in MEMS devices or leave tack layers on imaging device wafers, leading to device failure.
Innovation solutions
A device wafer processing method using an ultraviolet curable protective tape, where ultraviolet radiation is applied to specific areas to reduce adhesive force, allowing for controlled peeling without damaging the devices, while maintaining strong adhesion in peripheral areas to secure the wafer during grinding.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If a protective tape is attached to the front side of the MEMS wafer to protect the devices prior to grinding the back side of the wafer, then the devices are protected during grinding, but the microscopic structure in each device may be damaged in peeling the protective tape after the grinding step
Why choose this principle:
The patent applies different adhesive properties to different regions of the protective tape by selectively irradiating ultraviolet light to specific areas corresponding to devices with microscopic structures. This creates local variation in adhesive strength, allowing the tape to be peeled without damaging sensitive regions while maintaining protection during grinding.
Principle concept:
If a protective tape is attached to the front side of the MEMS wafer to protect the devices prior to grinding the back side of the wafer, then the devices are protected during grinding, but the microscopic structure in each device may be damaged in peeling the protective tape after the grinding step
Why choose this principle:
The patent performs preliminary ultraviolet irradiation to reduce adhesive force in specific areas before the peeling step. This preliminary action modifies the adhesive properties in advance, ensuring that when peeling occurs after grinding, the reduced adhesive force prevents damage to microscopic structures.
Application Domain
Data Source
AI summary:
A device wafer processing method using an ultraviolet curable protective tape, where ultraviolet radiation is applied to specific areas to reduce adhesive force, allowing for controlled peeling without damaging the devices, while maintaining strong adhesion in peripheral areas to secure the wafer during grinding.
Abstract
A device wafer includes a device area where a plurality of devices are formed on the front side of the device wafer and a peripheral marginal area surrounding the device area. Each device has an adhesion disliking region disliking adhesion to an adhesive tape. An ultraviolet curable protective tape is attached as the adhesive tape to the front side of the device wafer. Ultraviolet radiation is applied to a first area of the protective tape corresponding to the adhesion disliking region of the device wafer to thereby reduce the adhesive force in the first area. The ultraviolet radiation is not applied to a second area of the protective tape corresponding to the peripheral marginal area of the device wafer to thereby maintain the adhesive force in the second area. The device wafer is held through the protective tape while the back side of the device wafer is ground.