發(fā)布時(shí)間：2018-12-27 12:30

【摘要】：針對(duì)PCB飛針檢測(cè)的實(shí)際需要,以及檢測(cè)PCB微小缺陷造成的阻值變化,需要設(shè)計(jì)高精度的快速微阻測(cè)量?jī)x,本文詳細(xì)論述了現(xiàn)有飛針測(cè)試機(jī)的工作流程,以及制約其速度的關(guān)鍵因素,并且針對(duì)這些因素設(shè)計(jì)了一種全新的飛針測(cè)試機(jī)系統(tǒng)架構(gòu),在實(shí)際應(yīng)用中驗(yàn)證了其可行性。為了從低信噪比的信號(hào)中將有用信號(hào)提取出來,分別從理論上分析并仿真了模擬電路及數(shù)字信號(hào)處理這兩種方法的可行性。這兩種方法的基礎(chǔ)都是基于對(duì)噪聲來源及特性的分析,本設(shè)計(jì)也重點(diǎn)分析了噪聲和干擾的來源。同時(shí)在本論文中詳細(xì)分析了微阻測(cè)量中的噪聲,誤差來源以及微弱信號(hào)的檢測(cè)方法,提出了一種快速的基于FPGA的測(cè)量微阻的方法。整個(gè)系統(tǒng)包括硬件系統(tǒng)和軟件系統(tǒng),硬件系統(tǒng)包括恒流源設(shè)計(jì),放大器設(shè)計(jì),濾波電路設(shè)計(jì)及對(duì)被測(cè)電阻兩端電壓正反測(cè)電路;軟件系統(tǒng)主要是在飛針控制卡上完成,主要有基于FPGA的LMS算法程序,與工控機(jī)通訊的Socket程序。經(jīng)試驗(yàn)證明,該測(cè)量板可以快速的測(cè)量PCB微阻以及快速的上傳數(shù)據(jù)至工控機(jī),并且具有很高的測(cè)量精度和重復(fù)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.
【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN41

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本文編號(hào)：2393063