Vorrichtung zum Ausrichten eines Galvanisierkopfes relativ zu einem Halbleiter-Leiterrahmen

摘要

Apparatus is disclosed for accurately aligning a processing device with respect to a predetermined reference location on semiconductor lead frame. The apparatus is especially suitable for use with a plating head for plating the pads of a lead frame. The apparatus includes a drive motor having a precision lead screw for attachment to the processing device to shift the device through a small distance to accurately position the device with respect to the predetermined reference positions on the lead frame. The drive motor is coupled to a rotary encoder which is rotated in response to the movement of a pin positioned to enter a reference hole in the lead frame. As the lead frame is advanced by an indexing device, the pin enters a reference hole in the lead frame near the end of the travel of the lead frame, causing the rod to rotate the encoder and supply a signal which for comparison with a reference signal. The output of the comparator is applied to the motor for advancing the processing device incrementally to position it accurately with respect to the reference locations on the lead frame.