I would greatly appreciate any input regarding changing from HASL to OSP. We assemble heavy copper boards and are experiencing difficulties as we move to 0805 chip packages. We are comtemplating changing to OSP to alleviate some of the pain. I would appreciate any info regarding process changes we may have to make (pad design, pre-heat, flux application method, etc). A typical application is 4 layer board with 2 oz. internals and 2 oz. externals plated to 3 oz. Three thermal cycles (top side reflow, bottom side epoxy cure, and wave solder). SOIC and SOT-23 on top, 0805 on bottom, plus through hole components. No-clean paste and wave solder flux, wave flux applied by foaming on most machines but spray fluxer also available. Assemblies have high thermal mass (large magnetics and heatsinks). Thanks for your help. Pat Bailey Zytec Corporation phone 507 637-2966 x355 fax 507 644-3720 e-mail [log in to unmask]