Comparator for monitoring the deposition of an electrically conductive material on a leadframe to warn of improper operation of a leadframe electroplating process

摘要

A method and circuit (14) for monitoring an electroplating operation of an electroplating machine (10) of the type having a first electroplating cell (18) for depositing nickel onto an integrated circuit leadframe (12) and a second electroplating cell (19) for subsequently depositing palladium onto the leadframe (12). A first current (30) is applied in the first electroplating cell (18) to form a nickel deposit on the leadframe (12) and a second current (31) is applied in the second electroplating cell (19) to from a palladium deposit on the nickel deposit. The second current (31) is greater than the first current (30) if the electroplating machine (10) is operating normally. The first current (30) and second current (31) are compared in a comparator (44) during the electroplating operation, and if the second current (31) is less than the first current (30), an error signal is generated on an output line (50). If desired, the electroplating machine (10) may be stopped in response to the error signal.