Wire Bond Reliability Research Articles

Improving Thermosonic Gold Ball Bond Reliability

A comprehensive study using normal probability paper to project gold wire bond reliability has been performed. Reliability projections have been made using ceramic capillaries, tungsten carbide capillaries, gold wire, gold/palladium alloy wire, three different device metallizations, nine different wire lot numbers, and seven ultrasonic power settings. The reliability projections from all of the tests were then compared to the ball shear force from each test to correlate shear force with reliability. The results indicate that several orders of magnitude increase in reliability can be achieved from using optimum wire bond parameters. The ball shear force value has also been shown to be very useful in predicting reliability and thus eliminating time consuming wire pull tests.

Effects of Ambient Atmosphere on Aluminum - Copper wirebond Reliability

The effect of ambient atmosphere on the stability of Al-Cu bonds aged at 150 to 300°C was studied. Data show that atmosphere plays a major role in determining the failure mode of wires bonded and aged under otherwise identical conditions. Bonds aged in air, nitrogen, and vacuum all experienced an initial decrease in pull strength due to annealing of the wire. The mechanical strength of vacuum and nitrogen aged samples continued to degrade with time. A shift in the primary failure mode from wire breaks to bond lifts was noted. The pull strengths of air-aged samples remained stable through 1600 h. The dominant failure mode was wire breaks. Al-Cu intermetallic phases were formed under all conditions. Surface diffusion was suggested by the presence of a groove at the bond perimeter. With time, the groove propagated along the metallic Cu/Cu intermetallic interface, undercutting the bond. The formation of copper oxides in air-aged samples retarded this process. An effective activation energy of 0.45 eV was calculated for the Al-Cu failure mechanism in vacuum.

Wirebonding reliability techniques and analysis : G. H. Ebel, J. A. Jeffery and John P. Farrell. IEEE Trans. Components Hybrids mfg Technol.CHMT-5 (4), 441 (1982)

Wirebonding reliability techniques and analysis : G. H. Ebel, J. A. Jeffery and John P. Farrell. IEEE Trans. Components Hybrids mfg Technol.CHMT-5 (4), 441 (1982)

Wire-bond reliability in hybrid microcircuits : R. S. Spriggs and A. H. Cronshagen. IEEE 11th Annual Proceedings Reliability Physics (1973). p. 83

Wire-bond reliability in hybrid microcircuits : R. S. Spriggs and A. H. Cronshagen. IEEE 11th Annual Proceedings Reliability Physics (1973). p. 83