Adhesion has been identified as one of the key factors inpreventing popcorn problems in surface mount devices (SMD). Theobjective of this project was to study, by use of a controlledexperiment, the impact on adhesion and delamination of plastic packagesusing various preplated leadframes that had been subjected to stringentmanufacturing preconditions. This paper will ultimately show, throughstatistical analysis, that there is a very strong relationship betweentab adhesion and percent delamination. A Design Of Experiment (DOE-4×5×5 full factorial) was set up to study foursemiconductor molding compounds×five industry standard preplatedfinishes×five typical preconditioning stages. The statisticalresults showed that all the factors (mold compounds, preplatedleadframes and preconditioning) and all the 2-factor interactions weresignificant. Two key-examples were a very strong relationship betweencomputerized digital image analysis (CDIA) and Tab Pull, and the use ofoxidized leadframes which show exceptional tab pull strength and nearzero percent delamination via CDIA, under all conditions. Further workwill study the relationship of tab adhesion and percent delamination topopcorn effects
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