Adjustable wire tensioning apparatus

摘要

A multi-level fine wire tensioning apparatus is provided for use in high speed automatic wire bonders. The tensioning apparatus which surrounds the fine wire is mounted close to the bonding capillary and is adapted to apply one of a plurality of tension forces on the wire depending on the phase of the bonding cycle. The tensioning apparatus comprises a housing containing an aspirating tube which applies tension to the fine wire that is threaded through the tube. A controller is coupled to a high speed selector which connects one of a plurality of different level vacuum or pressure sources to the tensioning apparatus which in turn applies different tension forces to the fine wire in the capillary.