Wafer Recess and Protrusion Separation for Low-Chipping Dicing
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Solution Overview
Problem
Conventional chip manufacturing methods face issues with wafer breakage and warpage due to irregularities on the surface, leading to processing defects such as chipping during division into device chips.
Innovation Solution
A chip manufacturing method involving a protective member fixed to one surface of a wafer with a recess and loop-shaped protrusion on the other surface, processed to separate these features, and then divided into chips using a holding table and laser ablation to improve handling and reduce warpage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a recess and loop-shaped protrusion are formed on the other surface side of the wafer to prevent breakage and warpage, then wafer stability is improved, but large irregularities on the surface cause adhesion failure of the dicing tape
Solution Approach 1:
The wafer surface is segmented into different functional zones: a recess portion that provides warpage prevention and a surrounding protrusion portion that provides a flat adhesion surface for the dicing tape. This segmentation allows each zone to fulfill its specific function without interfering with the other.
Solution Approach 2:
Different surface qualities are applied to different locations: the recess portion has a concave shape optimized for mechanical stability and warpage control, while the surrounding protrusion portion maintains a flat surface optimized for adhesive bonding. This local differentiation resolves the conflict between stability and adhesion.
2Strength
If the wafer is thinned to form a recess and loop-shaped protrusion, then breakage resistance is improved, but processing defects such as chipping occur during division
Solution Approach 1:
The recess and protrusion structure is formed in advance during the thinning process, creating a pre-stabilized wafer configuration that maintains its shape and position stability throughout subsequent dicing operations, thereby preventing processing defects.
Solution Approach 2:
The loop-shaped protrusion acts as an intermediary structure that connects the recess portion to the surrounding wafer edge, providing mechanical support and stress distribution that prevents chipping during the division process.
3Productivity
If the recess and loop-shaped protrusion are separated to facilitate chip division, then chip manufacturing efficiency is improved, but wafer handling stability may be compromised
Solution Approach 1:
The separation process divides the wafer into individual chips while the recess and protrusion structures are simultaneously separated, allowing each chip to maintain its structural integrity through the inherited geometric features.
Solution Approach 2:
The recess and protrusion structures serve dual purposes: they provide stability during processing and automatically separate with the chip boundaries, eliminating the need for additional stabilization measures after separation.
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
The method effectively suppresses wafer warpage and facilitates handling, reducing processing defects like chipping by ensuring stable adhesion and precise separation of the wafer into individual chips.
Implementation Method 1
processing the wafer and the protective member along a boundary between the recess and the loop-shaped protrusion to separate the recess and the loop-shaped protrusion from each other
Data Source
AI summary
A chip manufacturing method includes: preparing a wafer unit having a protective member fixed to one surface of a wafer and having a recess and a loop-shaped protrusion surrounding the recess on the other surface side of the wafer, the protective member including a first sheet in contact with the wafer, a resin layer stacked on the first sheet, and a second sheet stacked on the resin layer; processing the wafer and the protective member along a boundary between the recess and the loop-shaped protrusion to separate the recess and the loop-shaped protrusion from each other; and after separating of the recess and the loop-shaped protrusion, holding the protective member side of the wafer on a holding table and dividing the wafer from the other surface side to manufacture a plurality of chips.