The Design Of Electrical Test System For Flying Probe Tester

With the rapid development of electronic industry,PCB electrical performance requirements is increasing.The traditional way of PCB testing takes a long time and high cost of production test fixture,it is difficult to meet the needs of various types of small batch,test sample plate and products frequently renewal.Facing these problems,flying probe tester is designed in this paper can.The rapid generation of test data based on PCB in the Gerber file,controlled by the Flying Probe Tester moving fast moving test probe system,test machine and electric measuring system interaction,effectively compensate for the testing method is not enough.The electrical measurement system is an important part of flying probe tester,its performance directly determines the efficiency and precision of the testing,in the selection of hardware design must take into account the two key indicators.Electrical measurement system to detect PCB defects with capacitance measurement,conduction test,insulation test,micro resistance test method and the integration of the four methods on the basis of these test methods,it has important significance to improve the overall performance of the machine.This paper first discusses the overall structure of the flying probe tester,some analysis of the influence of Flying Probe Tester detection efficiency,put forward to improve the efficiency of a system architecture.Then the system architecture of electric measuring system was part of the plan and the specific hardware and software design.In the hardware design part,first analysis the combination of flying needle,the micro resistance test four wire connection mode,the problem of signal noise micro resistance measurement are analyzed,then the selection and design of the hardware system,including constant current source and voltage source test,AD/ DA conversion circuit,capacitance testing circuit,power supply circuit and so on.In the software design part,mainly using STM32F303 as the control core,managed by the measurement and communication process,the communication protocol according to the actual needs of developed,gives the hardware initialization,hardware self-test subprogram,data mining Set and the median value of the procedures such as the realization of the process,and the software design.It is tested in the laboratory of electric measuring system of each function,verify the feasibility of hardware and software design of the system,the realization of arbitrary switching Flying Probe Tester four measuring method and four kinds of methods,preliminary requirements to achieve the accuracy and efficiency of the measuring system.In addition,in the field of flying probe tester the FBI test and in IPC derived test data of the four testing methods of data analysis,to remove the interference pulse of the machine itself,the test data has good linearity and repeatability.The test results prove that the flying probe test of electrical measuring system has better precision,and can be matched with the machine motion control system for rapid measurement.It has a good application prospect.