摘要
采集键合试验的PZT驱动功率及对应键合点的剪切测试力数据,作为超声功率和引线键合强度的表征。试验中的键合力、温度和时间分别设置为4．7 N、室温和100 ms。在这种典型的工业工艺键合参数下,通过改变超声功率比(设定超声功率与最大可调功率之比)来改变超声功率,研究了超声功率对引线键合强度的影响规律。试验中超声功率比在15%～100%之间做了20种设置,共进行了20组1000次键合试验。结果表明:超声功率小于3．5 W时,键合强度受超声功率的影响规律明显,即当超声功率小于1．0 W时,增加超声功率将增加键合强度,并减少剪切测试力为0的情况;大于1．6 W后则反之;而在1．0～1．6 W之间则可获得稳定可靠的键合强度,也就是在上述试验条件下的键合窗口;超声功率超过3．5 W后,规律不明显。此外,超声功率除受超声功率比这(?)可控因素影响外,还受基板质量不均匀、劈刀与铝丝间约束不确定等随机因素影响,超声引线键合是一个敏感的过程。
The PZT driver signal during bonding process and the shear test force of the corresponding wire bonding point are acquired as the indicator of ultrasonic power and bonding strength respectively in the large aluminum wire wedge bonding experiments. The bonding force, temperature and time are 4.7 N, room temperature and 100 ms respectively, which are selected according to industrial practice. The effect of ultrasonic power on large aluminum wire wedge bonding strength is studied by changing the ultrasonic power rate, which is defined as the rate between set and maximum ultrasonic power. 1 000 times bonding experiments in 20 groups are done, with 20 kinds ultrasonic power rate set between 15%-100%. Correlation between the ultrasonic power and the bonding strength is found. When ultrasonic power is less then 1.0 W, the bonding strength will increase with the power increase while the fail bonding will decrease, and the opposite will happen when ultrasonic power is larger than 1.6 W. Only when ultrasonic power is between 1.0 W and 1.6 W, can stable and high yield bonding be reached. And when larger then 3.5 W, there are no obvious rules. Moreover, ultrasonic power is effect by ultrasonic power ratio and other uncontrolled factors such substrate quality, restricts between tool and wire, and so on.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2007年第3期107-111,共5页
Journal of Mechanical Engineering
基金
国家重点基础研究发展计划(973计划
2003CB716202)
国家自然科学基金(50390064
50575230)资助项目。
