设计了Au—Al键合点的温度冲击试验,分析了键合点的力学特性、结构形貌及电学性能。结果表明Au—Al键合界面无裂纹产生,且机械性能良好,键合拉力在3.0~12.0g之间;高温导致Au—Al间形成了电阻率较高的化合物Au5Al2;最终引起键合电失效。对目前工艺水平下的Au—Al键合可靠性进行了评价,发现其寿命分布服从威布尔分布规律。用图估法估算取置信度为95%时,特征寿命η为547h,形状参数m为3.83。基于器件可靠性评价规律预测出了该工艺条件下制备的Au—Al键舍寿命,取可靠度为90%时,试验样品在常温25℃时的寿命为1.8×10^5h,约20年。
The thermal shock experiment of gold-aluminum bonding has been carried out. The mechanical characteristics, structure morphology and electrical characteristics degradation mechanism have also been researched. No cracks were observed in the bonding interface,and the bonding joints also showed good mechanical characteristics with pull stress of 3.0 to 12.0g. Due to high temperature, the gold-aluminum intermetallic compound Au5 Al2 with high resistibility was formed,which led to electrical failure ultimately. For the samples which were fabricated based on the present technique,the bonding reliability has been evaluated. It has been found that the lifetime rule obeys weibull distribution,and at high temperature of 150℃ under 95% confidence level the estimated results are η= 547h,m= 3.83. During the room temperature environment, Al-Au bonding samples' lifetime has also been predicted based on the rule of reliability evaluation, and the result shows that the lifetime is about 20 years, while reliability degree is 90%.