Improving Of Taguchi's Method And Its Application To The Process Of Stencil Printing

In order to respond to the tendency of the consumption electronic products which longs for light,thin,short and small,the electronic assembly technology experiences unceasingly improves.The Surface Mount Technology has become the mainstream in the modern electron assembly industry.Its merit lies in reducing the production cost and making the high quality of the electronic products.However,just as the production system of SMT involves many factors,such as machines,materials, working conditions and so on,and is more complex than the traditional manufacture flow.Therefore,in order to enhance the quality of product,how to control the production system of SMT becomes the important issue in the field.The production system of SMT mainly includes six steps which are stencil printing,component placement,reflow soldering,adhesive dispense,wave soldering and inspection.Stencil printing acts as the first important step in the production line. If solder paste is insufficient,the missing solder will occur.If solder paste is excessive,the phenomenon of bridge joint will lead to short circuit.Generally speaking,the factors which affects in the process of stencil printing includes the size and shape of stencil,the pressure and angle of shaving knife,printing speed,snap-off, wipe frequency,the type of solder paste,temperature,humidity and so on.This research combines the Minitab statistics software and Taguchi's method to optimize parameters in the process of stencil printing.Firstly,through to the consideration to the counting quality characteristic and definite purpose of quality characteristic which has the adjustment factor,the introduction of examination factor,the revision to the orthogonal array,the complete examination system and so on,build the modified Taguchi's method.Secondly,based on the design of 0201 parts,solder pad,stencil,printer and measure system,we can build the experiment platform.Then,as to the essential parameter,we design appropriate orthogonal array and carry on the experiment according to the table.By the confirmation to the tentative data and the analysis model,we obtain the optimized combination of parameters by the analysis of S/N, variance and sensitivity.The optimized combination of parameters is 45°angel of shaving knife,25mm/s speed of shaving knife,0.1mm/s speed of snap-off is,4 PCB/time wipe frequency.Thirdly,execute the confirming experiment and analyze the process ability in the process of stencil printing.Just as the overlaps of confidence interval between the confirmation experiment value and the forecast value,we can confirm the reproducibility and robustness of the optimized result.Through the quantification of the affection of improvement,the loss of quality reduces to 65.5%of the former.Finally,has confirmed the effect of improvement in Taguchi's method through the contrastive analysis.