Wafer Support Vacuum Channels for Flat Laser Dicing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wafer dicing processes face challenges with wafer warpage due to gravity and vacuum suction, which affects laser focusing alignment and dicing yield.
Innovation Solution
A wafer supporting mechanism with a base portion and support portion, featuring gas channels and outlets, provides vacuum suction to fixate the wafer, preventing warpage and improving alignment accuracy during dicing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum suction is applied to fixate the wafer on the chuck table, then the wafer is held firmly in place, but the wafer becomes deformed or warped due to the vacuum force
Solution Approach 1:
The chuck table is divided into multiple independent vacuum regions separated by partition walls. Each region can be independently controlled, allowing the vacuum force to be distributed across multiple smaller areas rather than concentrated on a single large surface, thereby reducing the deformation caused by vacuum suction
Solution Approach 2:
Different regions of the chuck table have different vacuum pressures applied to them. The vacuum force is locally adjusted to match the wafer's structural characteristics, applying stronger vacuum where needed for fixation and weaker vacuum where the wafer is more susceptible to deformation
2Ease of manufacture
If the wafer is disposed on the chuck table with back side facing up, then laser stealth dicing can be performed, but the wafer warpage increases due to gravity force
Solution Approach 1:
The partition walls create a structural framework that acts as a counterweight system, providing mechanical support to counteract the gravitational force on the wafer. The walls are positioned to provide support exactly where the wafer needs it most to maintain flatness during back-side laser dicing
Solution Approach 2:
The partition walls serve as intermediary structures between the chuck table surface and the wafer. These walls provide mechanical support and distribute the gravitational load, preventing the wafer from sagging under its own weight when positioned for laser stealth dicing
3Measurement precision
If the wafer surface warpage is great enough, then the laser focusing alignment cannot be performed, but increasing vacuum suction to prevent warpage causes more deformation
Solution Approach 1:
The system monitors wafer position and laser alignment status, and adjusts vacuum pressure in real-time. When warpage is detected that would interfere with laser focusing, the feedback control system modifies the vacuum pressure distribution to correct the warpage while maintaining fixation, ensuring optimal conditions for laser focusing alignment
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 mechanism effectively reduces wafer warpage, enhances dicing yield, and allows for precise laser alignment, increasing the number of separated semiconductor devices per wafer.
Implementation Method 1
fixating the wafer to the wafer supporting mechanism by exhausting gas from the gas channel through the first outlet
Data Source
AI summary
A wafer supporting mechanism and a method for wafer dicing are provided. The wafer supporting mechanism includes a base portion and a support portion. The base portion includes a first gas channel and a first outlet connected to the first gas channel. The support portion is connected to the base portion and including a second gas channel connected to the first gas channel. An accommodation space is defined by the base portion and the support portion.