Research On Early Failure Analysis And Elimination Technology Of NC System

Early failure is an important factor,which affect the reliability level of NC system,it is key to realize the reliability growth of NC system by researching on its failure mode,mechanism and corresponding control technology.In this paper,a series of domestic NC system as the research object,study the causes of its early failure and the corresponding control methods,the main contents are as follows:1.Through reliability test and repair data of NC system,establish the Weibull distribution model.The result shows that mean time between failure is 12096 h,the early failure period continue 3.03 months.2.From the failure mechanism and data of the servo drive unit,the failure mode of rectifier bridge is bonding wires off.By Icepak and Abqus simulation,the result shows that both the temperature of chip and aluminum block grow up with the increase number of bonding wires off.3.Based on the analysis,through aging screening and temperature cycling test for screening the bonding wires off.The result shows that temperature cycling test is more effective than aging screening.But the parameters in temperature cycling test need to be further optimized.It researches on failures aiming at shortening the period of early failure under improving the parts reliability of NC system,and come up with authenticated elimination technology for solving failures,which is of great meaningful for reliability growth and estimate of NC system.