Meaning
Compliance mechanism in a probe card that uses a flexible beam to establish an electrical connection with a semiconductor wafer. The micro cantilever contact provides the necessary spring force to penetrate oxides. This design is common in high-parallelism testing where thousands of pins must land simultaneously.
Force Balance
Geometry of the beam determines the relationship between vertical travel and contact pressure. A micro cantilever contact deflects upon touching the wafer, and this deflection generates a scrubbing motion. The horizontal slide ensures a clean metal-to-metal interface by cutting through the aluminum oxide layer on the pad surface.
Alignment Accuracy
Precise positioning of the tip is required to hit the center of the target area. The micro cantilever contact is susceptible to thermal expansion, which can cause the tip to drift away from the pad during long test cycles. Advanced materials with low thermal expansion coefficients are used to maintain the position of the probes across a wide temperature range.
Maintenance Protocol
Wear on the tip changes the shape and size of the scrub mark over time. Each micro cantilever contact is inspected periodically for tip blunting or contamination. Cleaning blocks are used between test runs to remove debris and maintain the electrical performance of the probe head.
