The router was causing 3,000 µε (double the IPC limit). By slowing the routing speed by 40% (per IPC-9704 guidance), they reduced strain to 800 µε. Failure rate dropped to 0.1%.
: Defines equipment requirements and excitation voltages (typically 2V for PCB materials). Strain Measurement ipc-9704 pdf
(0°/45°/90°). These capture the full 2D strain state on the board surface, which single-axis gages cannot do. Placement Strategy The router was causing 3,000 µε (double the IPC limit)
The goal is to prevent (cracks) that may not be visible during in-circuit testing but will cause field returns months later. The router was causing 3