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Wang Fuliang
Han Lei
Zhong Jue
College of Mechanical and
Electrical Engineering,
Central South University,
Changsha 410083, China |
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EFFECT OF
ULTRASONIC POWER ON
THE HEAVY ALUMINUM WEDGE
BONDING STRENGTH*
Abstract:
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 µm 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.
Key words:
Ultrasonic wire bonding Ultrasonic power Over bonding Heavy aluminum wire |