Wafer Cleaving Sequence to Prevent Crack Expansion During Dicing
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Solution Overview
Problem
The existing manufacturing methods for semiconductor devices, such as the scribing and breaking process, often cause damage to wafers due to the expansion of vertical cracks generated during the adhesive removal process, as the thick adhesive layer creates stress that can further propagate the cracks.
Innovation Solution
A method where the support plate is separated from the wafer while leaving the adhesive on the first surface, and the wafer is cleaved along the boundary using a breaking bar over the adhesive, ensuring the wafer is already cracked when the adhesive is removed, thereby minimizing further crack expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the adhesive is removed after the wafer is cut, then the semiconductor elements can be separated from the support plate, but the vertical cracks may expand and cause wafer damage due to stress from the thick adhesive layer
Solution Approach 1:
The wafer is cleaved along the boundary before the adhesive is removed. By performing the cleaving operation in advance, the patent ensures that the separation path is established while the adhesive is still present and providing structural support, thereby preventing crack expansion during the subsequent adhesive removal process
Solution Approach 2:
The patent applies preliminary anti-action by creating the cleave path before adhesive removal to counteract the potential harmful effect of crack expansion. The early establishment of the separation boundary prevents the adhesive stress from causing damage during removal
2Strength
If a thick adhesive layer is used to attach the support plate to the wafer, then the support is strengthened, but stress during adhesive removal can expand vertical cracks and damage the wafer
Solution Approach 1:
The cleaving operation is performed in advance while the thick adhesive layer is still providing structural support. This preliminary action ensures that the separation path is established before the adhesive removal process begins, allowing the thick adhesive to fulfill its support function without causing crack expansion
3Reliability
If the wafer is cleaved before adhesive removal, then crack expansion is minimized, but the process sequence becomes more complex
Solution Approach 1:
The patent incorporates the cleaving operation as a preliminary step in the existing manufacturing process flow. By integrating this action early in the sequence while the wafer is still on the support plate, the patent avoids adding significant complexity while achieving the benefit of minimized crack expansion
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 likelihood of wafer damage by ensuring the vertical crack is formed before adhesive removal, maintaining the integrity of the semiconductor elements during the separation process.
Implementation Method 1
forming a vertical crack inside the wafer along a boundary between the adjacent semiconductor elements by pressing a scribe wheel against the wafer along the boundary
Implementation Method 2
a support plate is attached to a first surface on which a plurality of semiconductor elements is formed through an adhesive
Data Source
AI summary
A manufacturing method of a semiconductor device, includes: preparing a wafer having a first surface on which a plurality of semiconductor elements is formed and to which a support plate is attached through an adhesive; grinding a second surface of the wafer opposite to the first surface in a state where the support plate is attached to the first surface of the wafer; forming a vertical crack inside the wafer and along a boundary between the adjacent semiconductor elements by pressing a scribe wheel against the wafer along the boundary; separating the support plate from the wafer while leaving the adhesive on the first surface of the wafer; cleaving the wafer along the boundary by pressing a breaking bar against the wafer over the adhesive and along the boundary; and removing the adhesive from at least one of the semiconductor elements divided from the wafer by the cleaving.