Processing strategies for high speed 0201 implementation

A lot of research has been done to determine the board design considerations for 0201 processing, but work also needs to be done to determine the process window. Initial data presented last year showed a number of significant factors in the printing, placement, and reflow processes. From that study, the individual process steps showed that certain design and manufacturing parameters can have a huge effect upon total process defects. Presented in this paper is the data from those studies as well as the data gathered after a large evaluation run in which many components were processed. Studied process parameters were broken out by individual process steps initially, and then studied over the entire process. Some of the process parameters that were examined were stencil manufacturing method, print force, print speed, and stencil wipe frequency for the printing process and reflow atmosphere, profile shape, and ramp rate for the reflow process. From these studies, a reliable process window was obtained for a high speed 0201 assembly process that was proven to provide a 17 DPM (defect per million) assembly yield.