Silicon Bridge Guard Ring Layout for Crack-Free Saw Singulation
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Solution Overview
Problem
Conventional silicon bridge technology faces challenges in handling and cutting ultra-thin wafers due to thick copper metal layers, leading to die cracks and high costs associated with laser scribing, which are not amenable to side-by-side guard rings with a moat structure.
Innovation Solution
A dual guard ring frame design with a metal-free scribe line zone and staggered metal layer dummification between guard rings, allowing for a saw-only die singulation process that minimizes die crack propagation and eliminates the need for expensive laser scribing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If laser scribing is used to cut ultra-thin wafers with thick copper metal layers, then cutting can be achieved, but die cracks occur and costs increase
Solution Approach 1:
The wafer is segmented into multiple regions: active die regions and metal-free scribe line regions. This segmentation allows different processing approaches for different areas, enabling mechanical sawing in metal-free zones without causing cracks in the active die regions containing thick copper layers.
Solution Approach 2:
Metal is extracted or removed from the scribe line regions, creating metal-free zones. This extraction eliminates the harmful factor (thick copper layers) from the cutting areas, allowing safe mechanical sawing without die cracks while preserving the metal layers in active die regions.
2Ease of manufacture
If laser scribing is used for die singulation, then cutting is achieved, but production costs increase
Solution Approach 1:
The patent replaces the expensive laser scribing process with a mechanical sawing process. By creating metal-free scribe line regions, the design enables cost-effective mechanical cutting while avoiding the high costs associated with laser scribing of thick metal layers.
3Reliability
If side-by-side guard rings with moat structure are used, then die protection is improved, but compatibility with laser scribing is lost
Solution Approach 1:
The patent applies local quality by creating metal-free zones specifically in the scribe line regions while maintaining metal layers in active die regions. This localized modification enables mechanical sawing in scribe lines without affecting the protective guard ring structures in active areas, achieving both die protection and process compatibility.
Data Source
AI summary
Metal-free frame designs for silicon bridges for semiconductor packages and the resulting silicon bridges and semiconductor packages are described. In an example, a semiconductor structure includes a substrate having an insulating layer disposed thereon, the substrate having a perimeter. A metallization structure is disposed on the insulating layer, the metallization structure including conductive routing disposed in a dielectric material stack. A first metal guard ring is disposed in the dielectric material stack and surrounds the conductive routing. A second metal guard ring is disposed in the dielectric material stack and surrounds the first metal guard ring. A metal-free region of the dielectric material stack surrounds the second metal guard ring. The metal-free region is disposed adjacent to the second metal guard ring and adjacent to the perimeter of the substrate.