Research On Periodic Decision-making Method Of Stencil Printing Machine Stencil Cleaning

Solder paste printing are the key equipment for the production and processing of printed circuit boards in surface mount production lines.During the solder paste printing process,solder paste often adheres to the stencil and is contaminated,resulting in deterioration of the solder paste printing machine,and thus the PCB.Print defects have gradually increased.Cleaning stencils is an effective way to improve the performance of solder paste printing,but frequent cleaning will not only cause problems such as excessive use of cleaning mechanisms,increased production costs,reduced service life of stencils,and waste of cleaning materials,but also lead to a large number of problems.The interruption of production affects the production efficiency of solder paste printing.In the highly automated SMT production line,because the printing press is in the SMT production line,frequent cleaning may even result in the interruption of the entire production line,seriously affecting the production efficiency of the company.Therefore,it is of great significance to make reasonable control of the cleaning decision of printing machine stencils.This article combines the national intelligent manufacturing special "mobile terminal board intelligent manufacturing new model" topic,to solder paste printing machine stencil reliability modeling as an entry point,the ratio of cleaning and repair time for the steel net cleaning the goal of the decision,the SMT The stencil cleaning strategy of production line solder paste printing has been studied in-depth,aiming to propose a stencil cleaning decision method that can reduce production costs and improve production quality and production efficiency.First,build a research framework for stencil cleaning decisions.Introduce the printing process of the solder paste printer,introduce each key process,describe the contamination phenomenon of the solder paste printing machine,count the printing defects caused by the pollution and analyze the factors that affect the printing,and propose solder paste printing machine stencils.Cleaning decision-making issues;establishing a research framework for SMT production line stencil cleaning decisions;analysing the goals,influencing factors,and modeling techniques for stencil cleaning decisions.Then,stencil cleaning decisions are modeled.Based on the reliability theory,the decision-making target cleansing and rework repair ratio is established,the decision variable is the washing frequency cleaning frequency decision model,and the golden section method is used to find the optimal solution of the model.Finally,based on the above research,the experimental data is analyzed and processed.Based on the experimental data,using matlab software to fit the print failure time distribution,and make hypothesis testing to verify the correctness of the Weibull distribution to describe the print failure time distribution;analyze and discuss respectively the print failure time distribution parameters,the expectation of return time,manual cleaning The effect of time on the proportion of cleaning and rework time within a single cycle.