Jet Ablation Die Singulation for Crack-Free Thin Semiconductor Die
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional singulation methods for semiconductor die, such as sawing, induce die chipping and cracking, reducing yield and affecting device reliability, especially for thin die less than 50 microns in thickness.
Innovation Solution
A method involving forming a pattern in the back metal layer of a semiconductor substrate, etching substantially through its thickness, and jet ablating the passivation material from the second side to singulate the die, which reduces the need for additional photolithographic steps and minimizes die 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 reducing yield and reliability
Solution Approach 1:
The patent replaces the mechanical sawing system with a chemical etching system. Instead of using physical blades to cut through the substrate, the invention uses chemically reactive gases in a plasma state to selectively remove material at the patterned regions, thereby singulating the die without mechanical contact that causes chipping and cracking
Solution Approach 2:
The patent changes the physical state and chemical properties of the processing medium. By using plasma (ionized gas) instead of solid saw blades, and by controlling etch chemistry parameters, the process achieves clean separation without mechanical stress. The etch selectivity between different materials is also utilized to protect certain layers while removing others
2Reliability
If jet ablation is used to remove passivation material, then die singulation is achieved with minimal breakage, but additional processing steps are required
Solution Approach 1:
The patent combines multiple functions into integrated process steps. The etching process simultaneously performs substrate thinning, die separation, and removal of sacrificial layers. The demounting and remounting operations are integrated into the overall flow to enable access to both sides of the substrate for complete singulation
Solution Approach 2:
The patent performs preliminary patterning of the back metal layer before the main etching process. This pre-patterned layer serves as a mask or guide for subsequent etching steps, ensuring precise singulation paths. The passivation material is strategically designed to be removed at specific stages to facilitate the singulation process
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 efficient processing and packaging of semiconductor die without the need for sawing, thereby enhancing the reliability of semiconductor devices.
Implementation Method 1
jet ablating a layer of passivation material coupled to a second side of the semiconductor substrate to singulate the plurality of semiconductor die
Implementation Method 2
Etching substantially through the thickness of the semiconductor substrate further includes plasma etching
Data Source
AI summary
Implementations of a method singulating a plurality of semiconductor die. Implementations may include: forming a pattern in a back metal layer coupled on a first side of a semiconductor substrate where the semiconductor substrate includes a plurality of semiconductor die. The method may include etching substantially through a thickness of the semiconductor substrate at the pattern in the back metal layer and jet ablating a layer of passivation material coupled to a second side of the semiconductor substrate to singulate the plurality of semiconductor die.