基于FPGA的快速PCB微电阻测量仪的设计
发布时间：2018-12-27 12:30
【摘要】：针对PCB飞针检测的实际需要,以及检测PCB微小缺陷造成的阻值变化,需要设计高精度的快速微阻测量仪,本文详细论述了现有飞针测试机的工作流程,以及制约其速度的关键因素,并且针对这些因素设计了一种全新的飞针测试机系统架构,在实际应用中验证了其可行性。为了从低信噪比的信号中将有用信号提取出来,分别从理论上分析并仿真了模拟电路及数字信号处理这两种方法的可行性。这两种方法的基础都是基于对噪声来源及特性的分析,本设计也重点分析了噪声和干扰的来源。同时在本论文中详细分析了微阻测量中的噪声,误差来源以及微弱信号的检测方法,提出了一种快速的基于FPGA的测量微阻的方法。整个系统包括硬件系统和软件系统,硬件系统包括恒流源设计,放大器设计,滤波电路设计及对被测电阻两端电压正反测电路;软件系统主要是在飞针控制卡上完成,主要有基于FPGA的LMS算法程序,与工控机通讯的Socket程序。经试验证明,该测量板可以快速的测量PCB微阻以及快速的上传数据至工控机,并且具有很高的测量精度和重复精度。
[Abstract]:In view of the actual need of PCB flying needle detection and the change of resistance caused by small defects of PCB, it is necessary to design a fast micro resistance measuring instrument with high precision. This paper discusses in detail the work flow of the existing flying needle testing machine. And the key factors that restrict the speed of the flying needle test machine are designed, and a new structure of flying needle testing machine system is designed, which is proved to be feasible in practical application. In order to extract useful signals from low signal-to-noise ratio (SNR) signals, the feasibility of analog circuits and digital signal processing methods are analyzed and simulated theoretically. The two methods are based on the analysis of the source and characteristics of noise, and the sources of noise and interference are also analyzed in this design. At the same time, the noise, the source of error and the detection method of weak signal are analyzed in detail in this paper, and a fast method based on FPGA is proposed. The whole system includes hardware system and software system. The hardware system includes constant current source design, amplifier design, filter circuit design and voltage forward and inverse measurement circuit. The software system is mainly completed on the flying needle control card, mainly based on the LMS algorithm program based on FPGA, and the Socket program which communicates with the industrial control computer. The experimental results show that the PCB microresistance can be measured quickly and the data can be uploaded to the industrial computer quickly, and it has a high precision of measurement and repetition.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN41
[Abstract]:In view of the actual need of PCB flying needle detection and the change of resistance caused by small defects of PCB, it is necessary to design a fast micro resistance measuring instrument with high precision. This paper discusses in detail the work flow of the existing flying needle testing machine. And the key factors that restrict the speed of the flying needle test machine are designed, and a new structure of flying needle testing machine system is designed, which is proved to be feasible in practical application. In order to extract useful signals from low signal-to-noise ratio (SNR) signals, the feasibility of analog circuits and digital signal processing methods are analyzed and simulated theoretically. The two methods are based on the analysis of the source and characteristics of noise, and the sources of noise and interference are also analyzed in this design. At the same time, the noise, the source of error and the detection method of weak signal are analyzed in detail in this paper, and a fast method based on FPGA is proposed. The whole system includes hardware system and software system. The hardware system includes constant current source design, amplifier design, filter circuit design and voltage forward and inverse measurement circuit. The software system is mainly completed on the flying needle control card, mainly based on the LMS algorithm program based on FPGA, and the Socket program which communicates with the industrial control computer. The experimental results show that the PCB microresistance can be measured quickly and the data can be uploaded to the industrial computer quickly, and it has a high precision of measurement and repetition.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN41
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