Authors: William E. Coleman, Ph.D.and Matthew S. Read Company: Photo Stencil and Skyworks Solutions, Inc. Date Published: 10/14/2012
Abstract: Glue reservoir(1); solder paste reservoir(2), as well as two-print stencils(3) have been used in the past with some success. The present paper will explore a two-print stencil system for printing solder paste for a variety of SMT components including 0201 and 01005 components with a first stencil, and then printing flux into a reservoir pocket with relief pockets for the paste printed with the first stencil. The flux is printed for die attach. The reservoir depth varies from 75 to 150 microns deep and the flux dispense apertures vary in size from 65 microns up to 200 microns. Stencil design, print results, and assembly yields will be reviewed in the paper.