The laser can produce laser pulses to excite a device such as a silicon wafer, chip capacitor or chip packaged/silicon die containing a plurality of solder bumps into vibration.
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Summary: This invention is directed to high speed autofocus interferometric inspection systems and methods. Such an inspection system can generally include a laser module, an interferometer module, and a system controller. The laser can produce laser pulses to excite a device such as a silicon wafer, chip capacitor or chip packaged/silicon die containing a plurality of solder bumps into vibration. The interferometer module can be disposed to receive reflected laser energy from the device to sense vibration displacements created in the device with the laser pulses. The system controller to receive vibration data from the interferometer, the system controller configured to output a control signal for adjusting a relative distance and position between the laser module and the device.