Parameters of UV laser microvia formation based on Taguchi method of experiment design

Extremely quick progress in miniaturisation of electronic components determine PCB producers to research of new material and technological solutions. Indispensable element of present HDI PCB's are interlayer connections by using microvia techniques. Drilling by laser beam is one from manners of formation microvia. The use of UV laser permit sequentionally but in one technological operation, to open window in copper layer and then to drill the hole in dielectric layer. Course of drill process depends on large numbers of factors. Many factors mutually oneself influences. To qualify suitable value of particular factors would belong to pass numerically large series of single experiments. However using the Taguchi method of experiment design allow to limit of number of single experiments to tens and even a dozen or so. This method rested on advanced mathematics in univocal manner permits to qualify values of every from technological factors, at of which best results of experiments are received. Besides, that permits to estimate a power influence of individual factor on final result of experiment. This paper presents results of using of Taguchi method of experiment design to determine the best parameters of drilling microvias with ideal defined shape. The results are supported by an analysis of metallographic specimens.