一种探针台自动定位方法的研究与实现

Research and Implementation of an Automatic Locating Method on Probe System

探针台希望在上片后无需人工对准,就能从晶圆的第一个晶粒(第一点)开始检测,然而晶圆上片后,探针下方的开始位置往往并不是第一点;为了让第一点快速的移至探针下方,对平台的运行轨迹进行了研究,提出了螺旋定位法的概念,以平台上开始位置为中心,螺旋式步进运行,配合镜头的图像识别技术,一步一识别,逐步扩大范围,直至在镜头视野中找到晶圆中唯一的特殊晶粒(特殊点);由于第一点与特殊点的位置相对固定,所以找到了特殊点即找到了第一点;此方法经过算法分析及整合编程后,进行了多次试验,并交付客户使用,第一点都能快速移至探针正下方且长时间运行稳定;此自动定位方法不仅节省了人力成本,提高了定位精度,又大大地提升了探针台的工作效率。

The probe system is always supposed to detect from the first grain of the wafer without manual alignment after wafer up- load. However, the first position below the probe is often not ideal. In order to make the first grain below the probe quickly, spiral localiza- tion algorithm is coming out. The unique special grain of the wafer should be found first. The platform is treating the first position as the center and step moving spirally, the search range is extending step by step until find the special grain. Since the location of the first grain and the special grain is relatively fixed, so the first grain can be easily found after special grain. This method has carried on the experiment many times after integrate programmed. Now the whole system has already consigned to usage, the movements work well and stably, spe- cial grain can be found very quickly. After all, this automatic locating method not only saves labor costs, to improve the positioning accura cy, and greatly improve the efficiency of the probe system.