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]