Fine pitch capillary bonding tool

摘要

An improved fine pitch bonding tool for use in automatic gold ball bonders for bonding fine gold wires onto closely spaced pads on semiconductors comprises a cylindrical body portion which fits into an ultrasonic transducer and is provided with a bottle-neck working tip on the other end of the body portion for bonding fine gold wires. The working tip is provided with a wire hole diameter less than 1.4 times the diameter of the fine wire to be bonded and is further provided with a chamfer diameter on the working tip which is less than 2.5 mils across. The total tip diameter on the working tip is less than 6 mils and the working face which comprises an annular ring between the chamfer diameter and the tip diameter is provided with a face angle of approximately 22 degrees plus or minus 3 degrees. Even though the bonding tool has a smaller area working face, it has been found to produce second bonds whose pull strength is equal to prior art capillary bonding tools having larger tip diameters and working faces.