Wafer Separation Using Wax Layer and Frame Support
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Solution Overview
Problem
The backside grinding process for semiconductor wafers often results in warpage and cracking due to lack of rigidity and thickness maintenance during processing and transportation, which existing technologies fail to adequately address.
Innovation Solution
A wafer assembly is created with a carrier and a layer of wax between the wafer and the carrier, where the carrier maintains rigidity and thickness, and a wafer frame is mounted on the wafer post-separation to further support it, using a system with a platform, robot arms, and a controller to manage temperature and separation processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the wafer is processed alone without carrier support, then the processing and handling are simpler, but the wafer lacks rigidity and thickness maintenance causing warpage and cracking
Solution Approach 1:
A carrier is introduced as an intermediary component to support the wafer during backside grinding. The carrier provides the necessary rigidity and structural support that the thin wafer lacks, preventing warpage and cracking while enabling the wafer to be processed and handled more easily.
Solution Approach 2:
The system combines the wafer with the carrier to form a composite structure. This composite provides both the functional properties of the wafer and the structural support of the carrier, resolving the contradiction between simplicity and strength.
2Length of moving object
If the wafer is thinned to reduce size, then the chip dimensions are smaller, but the wafer loses rigidity and becomes prone to damage
Solution Approach 1:
The carrier acts as a mediator that compensates for the lost rigidity when the wafer is thinned. By providing external support, the carrier enables the wafer to be reduced to thinner dimensions without becoming fragile or prone to warpage.
3Strength
If the wafer is mounted on carrier with wax layer, then the rigidity and thickness are maintained, but the separation process becomes more complex
Solution Approach 1:
The wax layer undergoes phase transition from solid to liquid when heated, enabling easy separation of the wafer from the carrier. This phase change mechanism simplifies the separation process despite the initial complexity of mounting with wax.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the risks of warpage and cracking during grinding and transportation by maintaining the wafer assembly's rigidity and thickness, and the wafer frame supports the wafer post-separation, ensuring stable handling and processing.
Implementation Method 1
The layer of wax is softened
Data Source
AI summary
A method of separating a wafer from a carrier includes placing a wafer assembly on a platform. The wafer assembly includes the wafer, the carrier, and a layer of wax between the wafer and the carrier. A wafer frame is mounted on the wafer of the wafer assembly. The layer of wax is softened. The wafer and the wafer frame mounted thereon are separated, by a first robot arm, from the carrier.