The thin wafer(such as BOC) is often cracked easily after Die-Attach process and large numbers of products in some semiconductor company failed as a result of crack.So it is urgent to get the solution to assure the qu...The thin wafer(such as BOC) is often cracked easily after Die-Attach process and large numbers of products in some semiconductor company failed as a result of crack.So it is urgent to get the solution to assure the quality and increase the yield.This article explained the relation of crack,the chip strength,as well as Die-Attach pin-up speed and how to solve that issue.For example,additional polishing process can significantly decrease the grind mark damage;pin-up speed optimization can make pin-up force best.So linear crack of thin chip can be avoided effectively.展开更多
激光与物体相互作用产生的频率转换特性,对于目标探测具有重要的意义。频率上转换回波信号具有强度弱、脉冲展宽、有相移等特性。根据这种回波特性,论文以PIN光电二极管为探测器件,采用锁定放大技术进行回波信号检测。通过前置放大电路...激光与物体相互作用产生的频率转换特性,对于目标探测具有重要的意义。频率上转换回波信号具有强度弱、脉冲展宽、有相移等特性。根据这种回波特性,论文以PIN光电二极管为探测器件,采用锁定放大技术进行回波信号检测。通过前置放大电路、交流信号放大电路完成回波信号的转换放大,运用相敏检波器实现回波信号提取,并搭建了回波探测系统。实验测试表明,基于锁定放大器的探测系统能够抑制杂波信号,从强噪声背景中提取有效回波信号,针对探测系统前方1.5 m处的探测靶标,系统的输出信噪比为16.9 d B。展开更多
文摘The thin wafer(such as BOC) is often cracked easily after Die-Attach process and large numbers of products in some semiconductor company failed as a result of crack.So it is urgent to get the solution to assure the quality and increase the yield.This article explained the relation of crack,the chip strength,as well as Die-Attach pin-up speed and how to solve that issue.For example,additional polishing process can significantly decrease the grind mark damage;pin-up speed optimization can make pin-up force best.So linear crack of thin chip can be avoided effectively.
文摘激光与物体相互作用产生的频率转换特性,对于目标探测具有重要的意义。频率上转换回波信号具有强度弱、脉冲展宽、有相移等特性。根据这种回波特性,论文以PIN光电二极管为探测器件,采用锁定放大技术进行回波信号检测。通过前置放大电路、交流信号放大电路完成回波信号的转换放大,运用相敏检波器实现回波信号提取,并搭建了回波探测系统。实验测试表明,基于锁定放大器的探测系统能够抑制杂波信号,从强噪声背景中提取有效回波信号,针对探测系统前方1.5 m处的探测靶标,系统的输出信噪比为16.9 d B。
