磁头无铅微焊点液滴飞溅和失效性分析

The Droplet Splashing Study and Failure Analysis for the Lead-Free Micro Solders Joint of the Magnetic Head

磁头无铅微焊点可靠性分析主要包括焊点前期液滴飞溅的防护和后期焊点失效性分析,在实际生产中,应用钎料球喷射连接技术时,钎料液滴飞溅时有发生,本文融合激光加热和氮气压力技术,建立了一种新的用于计算磁头内置DFH控制元件连接钎料液滴冲击速度的双液滴模型,同时,采用正交试验法对比了不同激光加热参数和氮气压力条件下磁头内置DFH控制元件连接钎料液滴飞溅的情况,并进一步融合可控扫描式磁场和偏置两种方法,研究了磁头微焊点的失效情况.试验结果表明:下落前,激光脉冲能量是决定液滴温度的主要因素;下落后,对钎料液滴温度影响最大的是钎料液滴的初始温度.磁头无铅微焊点失效是焊点液滴飞溅和金属间化合物共同作用的结果.

The rehability analysis for the magnetic head includes solders joint early drops splash protection and solders joint post failure analysis. In actual production, applying the jetting solder ball bonding （SBB） technology, solder splash have occurred frequently. Combining the laser heating and nitrogen pressure technology, this thesis aimed at building a new double of droplet model for calculating the striking velocity of the solder which is used to connect the Built-DFH in Slider, while different parameters of the laser heating and the nitrogen pressure are compared through the orthogonal test. The controllable scanning magnetic fields and bias are further incorporated and the failure of magnetic solder joint is studied. The results showed that before the solder falls,laser energy is the most important factor affecting the solder splash. After the solder falls, we find that the temperature of the melting ball has no decrease during the fall. The temperature of the impinging melting ball depends on its initial value. The failure of magnetic solder joint is caused by solder droplet splash and intermetallic compounds.