Device for laser bonding process control.

摘要

An optical process monitor primarily for use in laser wire bonding detects the reflectivity change of the wire (12) being bonded in order to provide feedback control of the high power laser (10) used for bonding the wire (12) to a pad (14). The beam of a low power laser (30) which is co-linear or combined with the high power laser beam is conducted to the bond site and reflected from the wire (12) during the bonding cycle. The change in reflectivity of the wire during the bonding cycle is detected from the reflected low power laser beam. A signal commensurate with the detected change of reflectivity is used to control the power or duration of the high power laser (10) during bonding.