Dual-Region Semiconductor Singulation with Floating Electrical Paths
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Solution Overview
Problem
Existing semiconductor singulation methods using Process Control Monitoring (PCM) systems and conductive contact pads in the same region lead to reduced chip production yield due to material differences causing cracks, cavities, and thermal stresses during mechanical or laser singulation.
Innovation Solution
The implementation of dual-region singulation, where PCM structures are placed within singulation regions and conductive contact pads are separated, allowing for electrical coupling through non-metallic paths to minimize metal content in singulation lanes and reduce damage during die separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PCM structures and conductive contact pads are placed in the same region, then monitoring function is achieved, but production yield decreases due to cracks and damage during singulation
Solution Approach 1:
The patent divides the wafer into two distinct regions: a singulation region containing PCM structures and a separate contact region containing conductive contact pads. This segmentation prevents the harmful interaction between metallic pads and singulation processes while maintaining both monitoring functionality and production yield.
Solution Approach 2:
The conductive contact pads are extracted from the singulation region and placed in a separate contact region. This removal eliminates the source of harmful factors (metallic materials with different thermal and mechanical properties) that cause cracks and damage during mechanical or laser singulation.
2Productivity
If mechanical sawing is used to singulate through metal pads, then die separation is achieved, but vibrations cause cracks and surface damage
Solution Approach 1:
The metallic contact pads are extracted from the singulation region, eliminating the material incompatibility that causes vibration-induced cracks during mechanical sawing. The singulation region contains only non-metallic materials with compatible mechanical and thermal properties.
3Productivity
If laser singulation is used on metallic and non-metallic materials, then die separation is achieved, but dissimilar heating causes material stresses
Solution Approach 1:
The metallic contact pads are removed from the singulation region, eliminating the dissimilar thermal expansion issues that occur during laser singulation. The remaining singulation region consists of materials with compatible thermal properties, reducing thermal stress.
4Measurement precision
If PCM structures are placed in lanes where dies are singulated, then monitoring is achieved, but singulation through metal pads reduces production yield
Solution Approach 1:
The wafer is segmented into a singulation region with PCM structures for monitoring and a separate contact region with conductive pads for electrical connections. This spatial separation allows both monitoring and high-yield production to coexist without interference.
Data Source
AI summary
A semiconductor die includes a semiconductor circuit disposed within or over a substrate. A conductive contact pad is disposed over the substrate outside the semiconductor circuit. A floating electrical path ends at a singulated edge of the die. The electrical path is electrically coupled to the conductive contact pad.