redundant via

**Redundant Via** is a **DFM (Design for Manufacturing) technique where multiple vias are placed in parallel at each via connection** — providing backup current paths in case one via fails due to voiding, misalignment, or process defects. **What Is a Redundant Via?** - **Standard**: 1 via connecting two metal layers. - **Redundant**: 2 or more vias at the same connection point. - **Impact**: If one via opens, the other(s) maintain the electrical connection. - **Area Cost**: Requires extra routing space — automated tools optimize placement. **Why It Matters** - **Reliability**: Single-via connections are the most vulnerable points in the interconnect. Redundancy provides 10-100x improvement in via reliability. - **Yield**: Compensates for process defects (incomplete fill, misalignment) that affect individual vias. - **Design Rules**: Many foundries strongly recommend or mandate redundant vias for production designs. **Redundant Via** is **the backup parachute for interconnects** — ensuring that no single point of failure can break the electrical connection between metal layers.