基于变焦显微测量技术的键合金丝参数测量

欧美国家在半导体行业一直以来对我国实行技术封锁政策,我国许多关键技术和设备只能依靠进口,其中就包括键合金丝参数测量设备。键合金丝参数测量设备主要用于自动检测键合金丝的拱高和跨度等参数。由于键合金丝的回波损耗、驻波等微波传输特性与键合金丝的拱高、跨度等参数呈对应关系,因此可以通过测量相关参数的方法来检测键合金丝的微波传输特性是否合格。通过这一方法可以解决人工测量导致的速率低下的问题,提高键合质量检测效率,降低检测成本。本文基于变焦显微测量技术实现了键合金丝参数的测量。该方法通过自主设计的图像采集平台,获取到键合金丝的一组图像,然后进行聚焦区域提取,从而实现键合金丝的三维重建及参数测量。该方法对键合金丝拱高的测量精度<0.01 mm,相对误差<1.5%,对键合金丝跨度的测量精度<0.005 mm,相对误差<0.7%,可以满足自动检测键合金丝参数的设计需求。

Parameter measurement of gold bonding wires based on focus variation measurement

European and American countries have been implementing policies of technology blockade towards China in semiconductor industry. Many key technologies and equipment can only rely on import, including gold bonding wires parameter measuring equipment. The gold bonding wires measuring equipment is mainly used to automatically detect the arch height and span of the bonding wire. Because the microwave transmission characteristics such as return loss and standing wave of the gold bonding wires are corresponding to the parameters such as the arch height and span of the gold bonding wires, the microwave transmission characteristics of the gold bonding wires can be detected by measuring the relevant parameters. This method can solve the problem of low speed caused by manual measurement, improve the detection efficiency of bonding quality and reduce the detection cost. In this paper, the gold bonding wires parameters are measured based on focus variation measurement. In this method, a group of images of the gold bonding wires are obtained through the self-designed image acquisition platform, and then the focus area is extracted, so as to realize the three-dimensional reconstruction and parameter measurement of the gold bonding wires. The measurement accuracy of the gold bonding wires arch height is less than 0.01 mm, and the relative error is less than 1.5%. The measurement accuracy of the span of the gold bonding wires is less than 0.005 mm, and the relative error is less than 0.7%. The method can meet the design requirements of automatic detection of gold bonding wires parameters.