Factors Affecting Stencil Aperture Design For Next Generation Ultra Fine Pitch Printing
Authors: Mark Whitmore, Jeff Schake, and Clive Ashmore Company: DEK Printing Machines Ltd Date Published: 5/14/2013
ICSR (Soldering and Reliability)
Abstract: Miniaturisation is pushing the stencil printing process. As features become smaller, solder paste transfer efficiency is becoming more critical. In latest research work, actual paste deposit volumes and transfer efficiency have been monitored and compared for both square and round apertures with area ratio’s ranging from 0.20 thru to 1.35. This covers apertures sizes of between 100 and 550 microns in a nominal 100 micron thick stencil foil. In addition, the effect of ultrasonically activated squeegees (ProActiv) has been assessed as part of the same experiment. A further comparison has also been made between type 4 and type 4.5 solder paste aswell. The data presented here will help provide guidelines for stencil aperture designs and strategies for ultra-fine pitch components such as 0.3CSP’s.
Paste transfer efficiency, paste volume, area ratio, aperture design, stencil printing, 0.3mm pitch CSP’s, ultra fine pitch components.