EFFECT OF ULTRASONIC POWER ON THE HEAVY ALUMINUM WEDGE BONDING STRENGTH

摘要

＜正＞Eleven groups of wire bonding experiments are carried out on an experiment platform （restructured with a U3000 heavy aluminum wedge wire bonder）.Pure silicon aluminum wire （300 μ in diameter,2.94-3.92 N in average pull force） and nickel coated aluminum substrates are used in the experiments.During the experiment process,only ultrasonic power rate parameter is changed and the other bonding parameters are kept as constant.The bonding force and time are 4.90 N and 100 ms respectively.After the bonding experiments,shear strength tests are carried out on the bonds as the bonding strength criterion.From those experiments and test results,some conclusions are obtained: In the small ultrasonic power rate conditions （about 20％-30％）,with the power increasing,the bonding strength enhances accordingly; However,in the large ultrasonic power rate conditions （about 45％-70％）,the bonding strength decreases accordingly and over bonding happens.Only when the ultrasonic power rate is in a moderate condition （about 35％-40％） can good and stabilized bonding strength be acquired.