IC ESD Bus Layout Using Bonding Wires Instead of Filler Cells
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Solution Overview
Problem
Existing integrated circuit electrostatic discharge (ESD) bus structures are inefficient in utilizing circuit area due to the need for filler cells, which also limits flexibility in internal circuit layout design and increases production costs for accommodating irregularly shaped circuits.
Innovation Solution
The integrated circuit ESD bus structure employs bonding wires to connect pad groups to a common ESD bus, effectively forming a continuous ESD bus without the need for filler cells, allowing for more flexible circuit layout and efficient use of circuit area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filler cells are placed in empty spaces between I/O pads to connect to ESD bus, then ESD protection is provided to circuit area, but circuit area is wasted and flexibility for internal circuit layout design is reduced
Solution Approach 1:
The invention extracts and removes the filler cells from the ESD bus structure, replacing them with direct routing of ESD bus lines through the circuit area. This eliminates the wasteful occupation of circuit area by non-functional filler cells while maintaining continuous ESD protection paths.
Solution Approach 2:
The ESD bus is segmented into multiple ESD bus lines that can be independently routed through different regions of the circuit area. This segmentation allows the ESD protection network to adapt to irregular circuit shapes without requiring filler cells to fill gaps, thus optimizing circuit area usage.
2Reliability
If filler cells are used to connect circuit area to ESD bus, then ESD protection is achieved, but flexibility for internal circuit layout design is limited
Solution Approach 1:
The ESD bus line routing is made dynamic and adaptable rather than fixed by filler cell positions. The ESD bus lines can be flexibly routed to follow the actual boundaries of irregularly shaped circuits, allowing the layout design to adapt to various circuit configurations without being constrained by predetermined filler cell locations.
Solution Approach 2:
The ESD protection structure is tailored to match the local geometry of the circuit area. ESD bus lines are routed locally along the actual circuit boundaries rather than using a uniform filler cell pattern, allowing the ESD protection to conform to irregular shapes and providing layout flexibility.
3Adaptability or versatility
If circuit area is increased to contain circuits with irregular shapes and different areas, then all circuits can be accommodated, but production cost increases
Solution Approach 1:
The invention changes the parameter of ESD bus routing from fixed grid-based (filler cell approach) to flexible boundary-following routing. This allows the ESD protection structure to efficiently accommodate irregularly shaped circuits of different areas without increasing the overall circuit area, as the ESD lines adapt to the actual circuit geometry rather than requiring additional space for filler cells.
Data Source
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AI summary
An integrated circuit ESD bus structure includes a circuit area; a plurality of electrostatic discharge (ESD) buses; a plurality of pad groups adjacent and connected to the plurality of ESD buses; a common ESD bus; and a plurality of bonding wires configured to connect the plurality of pad groups to the common ESD bus.