PID Trench Shielding for IC Transmission Line Leakage Control
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Solution Overview
Problem
Existing IC devices suffer from incomplete shielding of transmission lines, leading to undesired signal leakage and interference due to gaps between via shields, which are typically formed by laser or mechanical drilling.
Innovation Solution
Implementing a continuous conductive shield within a photoimageable dielectric (PID) material to form trenches along transmission lines, reducing signal leakage and interference by providing a continuous surface for electric field termination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If via shields are used to provide shielding for transmission lines, then some degree of shielding is achieved, but gaps exist between adjacent vias allowing RF signal leakage
Solution Approach 1:
Multiple via shields are merged into a single continuous conductive shield structure that spans across multiple metal layers, eliminating the gaps that exist between discrete via shields and providing complete shielding coverage around the transmission line
Solution Approach 2:
The shielding structure is made continuous by forming an unbroken conductive path through stacked vias that extend across multiple metal layers, ensuring uninterrupted shielding coverage that prevents RF signal leakage throughout the entire transmission line length
2Reliability
If laser drilling or mechanical drilling is used to form vias for via shields, then shielding structure can be formed, but the process is complex and costly
Solution Approach 1:
The mechanical drilling process is replaced with a photoimageable dielectric (PID) material-based fabrication process, where patterns are formed through photolithography and chemical etching, eliminating the need for complex laser or mechanical drilling equipment and reducing manufacturing complexity
Solution Approach 2:
The fabrication approach changes from mechanical/thermal processes (drilling) to photochemical processes (photolithography and etching), fundamentally changing the manufacturing parameters and enabling simpler, more cost-effective production of the continuous conductive shield structure
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
Trench shielding significantly reduces signal leakage and interference, offering improved isolation and shielding efficiency compared to conventional methods, while utilizing PID material simplifies manufacturing and lowers costs.
Implementation Method 1
Implementing a continuous conductive shield within a photoimageable dielectric (PID) material to form trenches along transmission lines
Implementation Method 2
the at least one continuous conductive shield is positioned to reduce leakage of a signal transmitted along the transmission line beyond a space defined by the at least one continuous conductive shield
Data Source
AI summary
In an aspect, an integrated circuit (IC) includes a photoimageable dielectric (PID), a transmission line disposed within the PID, and at least one continuous conductive shield disposed within the PID to reduce leakage of a signal transmitted along the transmission line beyond a space defined by at least one continuous conductive shield. In an aspect, the transmission line is a horizontal transmission line, and a first continuous conductive shield is disposed along a first side of the horizontal transmission line and a second continuous conductive shield is disposed along a second side opposite the first side of the horizontal transmission line. In an aspect, the transmission line is a vertical transmission line, and the continuous conductive shield is a cylindrical conductive shield concentric about the vertical transmission line.