Wafer Debonding System with Segmented Circular Blades
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Solution Overview
Problem
Conventional wafer debonding systems are inefficient and often result in wafer breakages and edge defects, particularly when attempting to separate thin wafers using mechanical or chemical methods, as they struggle to apply forces effectively without causing damage.
Innovation Solution
A wafer debonding system utilizing a pair of circular plate blades with adjustable thickness and edge shapes, combined with automatic optical inspection and programmable pulling heads, applies controlled forces and rotations to minimize damage during the debonding process, allowing for precise insertion and force application to separate wafers efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional mechanical or chemical methods are used to separate wafer stacks, then the debonding process can be performed, but wafer breakages and edge defects occur due to inability to apply forces effectively
Solution Approach 1:
The separating blade is divided into multiple segments or teeth that can independently interact with the wafer stack. This segmentation allows the force to be distributed across multiple contact points, reducing stress concentration that would cause wafer breakage while maintaining effective debonding capability
Solution Approach 2:
The separating blade features varying tooth geometries and densities at different locations - sharper, more closely spaced teeth at the leading edge for initial penetration, and progressively blunter, more widely spaced teeth toward the trailing edge for controlled separation. This local variation in quality allows the blade to effectively debond wafers while minimizing damage to wafer integrity
2Productivity
If a flat blade is repeatedly inserted and retracted at the bevel region while the wafer rotates, then debonding can be achieved, but large edge defect rates occur at the opposite side of the flat blade insertion point
Solution Approach 1:
The separating blade transitions from a flat design to a curved or rounded profile that follows the rotational path of the wafer. This curvature ensures continuous contact and uniform force distribution around the wafer circumference, eliminating the defect-prone opposite side caused by flat blade insertion and rotation
3Manufacturing precision
If double sided debonding systems are used, then the risk of defects near wafer edges is reduced, but larger pull force is required which may result in wafer breakages
Solution Approach 1:
The separating blade applies force progressively rather than all at once - initial teeth engage to create separation nucleation points, followed by sequential engagement of additional teeth that gradually propagate the separation front. This partial action approach achieves effective debonding with controlled, distributed forces that prevent wafer breakage
Data Source
AI summary
An apparatus and method for debonding a pair of bonded wafers are disclosed herein. In some embodiments, the debonding apparatus, comprises: a wafer chuck having a preset maximum lateral dimension and configured to rotate the pair of bonded wafers attached to a top surface of the wafer chuck, a pair of circular plate separating blades including a first separating blade and a second separating blade arranged diametrically opposite to each other at edges of the pair of bonded wafers, wherein the first and the second separating blades are inserted between a first and a second wafers of the pair of bonded wafers, and at least two pulling heads configured to pull the second wafer upwardly so as to debond the second wafer from the first wafer.