Jet Ablation Die Singulation for Thin Substrates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional singulation methods for semiconductor substrates, such as sawing, induce die chipping and cracking, which reduce yield and affect device reliability, especially for substrates less than 50 microns in thickness.
Innovation Solution
A method involving forming an opening in a passivation layer and etching through the semiconductor substrate to create etched sidewalls, followed by jet ablation from either side to remove overhanging passivation material, thereby singulating semiconductor die without the need for sawing and reducing breakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional sawing methods are used for singulation, then the singulation process can be completed, but die chipping and cracking occur which reduce yield and affect device reliability
Solution Approach 1:
The patent replaces the mechanical sawing system with a jet ablation system that uses high-velocity fluid jets to remove material. This substitution eliminates mechanical contact between the saw blade and the semiconductor substrate, thereby preventing die chipping and cracking while maintaining singulation effectiveness
Solution Approach 2:
The patent employs hydraulic or pneumatic jet streams (typically water or other fluids) to ablate and remove material during the singulation process. The high-velocity fluid jet selectively removes material along the scribe lines without mechanical contact, resolving the contradiction between productivity and reliability
2Productivity
If traditional sawing methods are used for singulation, then the singulation process can be completed, but substrate breakage increases especially for substrates less than 50 microns in thickness
Solution Approach 1:
The patent replaces mechanical sawing with jet ablation, eliminating the mechanical forces that cause substrate breakage. The high-velocity fluid jet provides a contactless cutting mechanism that is particularly beneficial for thin substrates less than 50 microns in thickness
Solution Approach 2:
The patent changes the fundamental parameter of the singulation process from mechanical force to fluid dynamic pressure. By controlling the velocity, pressure, and composition of the jet stream, the process can be optimized for thin substrates without causing breakage
3Reliability
If jet ablation is used to remove overhanging passivation material, then die strength and yield increase, but additional processing steps are required
Solution Approach 1:
The patent merges the singulation process with the passivation material removal process. By using jet ablation for both singulation and cleaning of overhanging passivation material in a single integrated step, the additional processing complexity is minimized while achieving improved die strength and yield
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 increases die strength and yield by eliminating die chipping and cracking, allowing for more reliable semiconductor devices by reducing the number of processing steps and avoiding the use of sawing, which can lead to substrate breakage.
Implementation Method 1
jet ablating one or more portions of the layer of passivation material that overhangs the etched sidewalls
Implementation Method 2
Etching substantially through the thickness of the semiconductor substrate may further include plasma etching
Data Source
AI summary
Implementations of a method of singulating a plurality of semiconductor die may include forming an opening in a layer of passivation material coupled to a second side of a semiconductor substrate; etching substantially through a thickness of the semiconductor substrate at the opening in the layer of passivation material to form etched sidewalls along the thickness at a plurality of die streets; and jet ablating one or more portions of the layer of passivation material that overhangs the etched sidewalls.