solder bridge

**Solder bridge** is the **unintended solder connection between adjacent pads or leads that causes electrical short circuits** - it is a common assembly defect in fine-pitch and high-density layouts. **What Is Solder bridge?** - **Definition**: Excess or mislocated solder forms conductive linkage between neighboring interconnects. - **Main Causes**: Overprint, stencil misalignment, poor paste release, and placement shift are typical drivers. - **High-Risk Areas**: Fine-pitch leads and dense BGA escape regions are especially susceptible. - **Detection**: Commonly caught by AOI, X-ray, and in-circuit test short checks. **Why Solder bridge Matters** - **Immediate Fail**: Bridging can cause hard shorts that prevent boot or damage circuits. - **Yield Loss**: Bridge defects often require rework or board scrap. - **Process Sensitivity**: Bridge trends reflect paste-volume and alignment control quality. - **Reliability**: Partial micro-bridges can cause intermittent failures under contamination or humidity. - **Scalability**: Bridge control becomes harder as pitch and component spacing shrink. **How It Is Used in Practice** - **Stencil Tuning**: Optimize aperture reductions and spacing for fine-pitch bridge mitigation. - **Alignment Control**: Maintain printer and placement registration with frequent calibration. - **Rapid Feedback**: Use AOI short-loop analytics to correct print drift in real time. Solder bridge is **a high-impact short-circuit defect in SMT assembly** - solder bridge reduction requires combined control of paste deposition, component alignment, and reflow wetting behavior.