Scribe Seal Feedthrough for IC Isolation
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Solution Overview
Problem
Integrated circuits (ICs) face mechanical damage and chemical impurity issues during test, assembly, and packaging operations, particularly during wafer sawing and encapsulation, which compromise the electrical integrity and reliability of IC components.
Innovation Solution
The implementation of an electrical feedthrough in the scribe seal that includes a conductive structure with penetrating segments, a vertical seal, and a horizontal diffusion barrier, which connects to the scribe seal and forms a continuous barrier to prevent mechanical damage and chemical impurities from reaching the interior region of the IC.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a scribe seal is used to separate interior and exterior regions, then isolation from mechanical damage and chemical impurities is improved, but electrical connection between regions deteriorates
Solution Approach 1:
The scribe seal is segmented to create discrete isolation zones rather than a continuous barrier. The seal is interrupted at specific locations to allow feedthrough structures to pass through, enabling electrical connections while maintaining isolation in other areas. This segmentation resolves the contradiction by allowing both isolation and electrical connectivity to coexist in different spatial zones.
Solution Approach 2:
Feedthrough structures serve as intermediary elements that bridge the interior and exterior regions through the scribe seal. These intermediaries provide dedicated pathways for electrical connections while the surrounding scribe seal material maintains chemical and mechanical isolation. The intermediary structures enable dual functionality - electrical connectivity where needed and isolation where required.
2Object-affected harmful factors
If the scribe seal is made continuous to prevent chemical impurities, then protection from chemical impurities is improved, but mechanical strength during wafer sawing deteriorates
Solution Approach 1:
The scribe seal is strategically segmented at locations where feedthrough structures are present, creating controlled discontinuities. These segments maintain chemical protection in regions where isolation is critical while reducing mechanical stress concentration points during wafer sawing operations. The segmentation allows the structure to flex and withstand mechanical forces without compromising overall chemical barrier integrity.
Solution Approach 2:
Different regions of the scribe seal have different properties - areas surrounding feedthrough structures are interrupted to allow penetration, while other regions maintain continuous sealing. This local differentiation optimizes both chemical protection and mechanical strength by tailoring the seal continuity to the specific functional requirements of each zone.
3Reliability
If penetrating segments are made wide to ensure electrical connection, then electrical conductivity is improved, but mechanical strength and crack propagation resistance deteriorate
Solution Approach 1:
The electrical connection is achieved not only through the width of penetrating segments in the horizontal plane but also by extending the conductive structure vertically through multiple layers and utilizing the third dimension. This dimensional transition allows for adequate electrical conductivity without requiring excessive horizontal width that would compromise mechanical strength.
Solution Approach 2:
The feedthrough structures utilize composite material systems combining conductive materials for electrical connection with mechanically robust materials for structural integrity. This composite approach enables the penetrating segments to provide sufficient electrical conductivity while maintaining the mechanical strength and crack propagation resistance required for reliable operation.
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 solution effectively isolates IC components from mechanical damage and chemical impurities, enhancing the mechanical strength of the feedthrough and reducing the propagation of cracks, thereby ensuring the electrical integrity and reliability of the ICs during processing operations.
Implementation Method 1
a horizontal diffusion barrier connects to the scribe seal and vertical seal in the interior region above or below the interior segment
Data Source
AI summary
A feedthrough in an IC scribe seal is disclosed. The feedthrough is structured to maintain isolation of components in the IC from mechanical damage and chemical impurities introduced during fabrication and assembly operations. A conductive structure penetrates the scribe seal, possibly in more than one location, connecting an interior region to an exterior region. A feedthrough vertical seal surrounds the conductive element in the IC and connects to the scribe seal. A horizontal diffusion barrier connects to the scribe seal and the feedthrough vertical seal. The feedthrough vertical seal, the horizontal diffusion barrier and the IC substrate form a continuous barrier to chemical impurities around the conductive element in the interior region. The conductive structure includes any combination of a doped region in an active area, an MOS transistor gate layer, and one or more interconnect metal layers. The feedthrough is compatible with aluminum and copper interconnect metallization.