Jet Ablation Die Singulation for Thin Substrate Crack Prevention
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Solution Overview
Problem
Traditional singulation methods for semiconductor die, such as sawing, induce die chipping and cracking, reducing yield and affecting device reliability due to the fragility of thin semiconductor substrates 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 jet ablation system that uses high-velocity fluid jets to remove material. This substitution eliminates mechanical contact between the saw blade and the thin semiconductor substrate, preventing the mechanical stresses that cause chipping and cracking in substrates less than 50 microns thick.
Solution Approach 2:
The invention employs hydraulic or pneumatic jet streams (typically water or other fluids under high pressure) to ablate and singulate the semiconductor die. The fluid jet delivers kinetic energy to selectively remove material along the singulation lines without mechanical contact, enabling clean separation of thin substrates without inducing structural damage.
2Manufacturing precision
If additional photolithographic steps are added to improve singulation quality, then manufacturing precision improves, but device complexity and processing time increase
Solution Approach 1:
The method performs preliminary patterning of the back metal layer before the jet ablation process. This pre-patterned metal layer serves as a guide or mask that defines the singulation paths, allowing the jet ablation to follow precise trajectories without requiring additional photolithographic steps during the singulation process itself.
Solution Approach 2:
The back metal layer serves multiple functions: it provides electrical connectivity, acts as a structural support layer, and serves as a patterning template for the jet ablation process. This multi-functionality eliminates the need for separate photolithographic patterning steps that would otherwise be required to define singulation lines.
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 enhances die strength and yield by eliminating die chipping and cracking, allowing for more efficient processing and packaging of thin semiconductor substrates without the need for sawing, thereby improving device reliability.
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.