一种三自由度并联纠偏平台的误差分析

Error analysis of a 3-DOF parallel positioning table

锡膏印刷作为SMT工艺流程的第一道工序,也是SMT质量的基础。针对平台纠偏定位精度不高而导致印刷后PCB锡膏偏移的问题,从全自动锡膏印刷机定位平台的结构分析出发,根据其运动特性,建立纠偏系统的数学模型和纠偏量的误差模型,分析了并联平台产生系统误差的原因和作用过程;利用误差分析中的微分法,建立了纠偏平台随机误差的模型,分析了各重要尺寸对纠偏精度的影响,并根据纠偏精度计算出了构件精度要求,对关键构件的选型和实际生产装配要求有指导意义。

Solder paste printing,which is the first process of SMT,it is also the basic building block of SMT quality.Since the positioning precision of the table is not too high which may cause offset of PCB solder paste after printing,the structure of the full automatic solder paste printer positioning table is analyzed at first in it.Then,based on the motion characteristics,a mathematical model and error model of the correction system are built to analyze reasons and process of system error occurrence for the platform.At last,a random error model of error correcting table is established with differentiation in error analysis to analyze the effect of important assembly dimensions to correction precision and figure out demand of the members＇ accuracy according to error correcting precision,which has guiding significance for lectotype of key member and practical assembly.