I have in the past poster details of my colour report on the effect of assembly yields by different solder finishes. A couple of years back I was asked to conduct a test programme to demonstrate the yield improvement with a flat finish. This work also included solderability testing and the development of a test for small solder pads. The report is FREE its in colour and you can get a copy of the report from the following contact: Art Wolfrum Shipley Company Inc Tel: 001 508 481 7950 Fax: 001 508 229 0853 In the UK the contact for the report: Phil Hunter Shipley Europe Tel: 01203 457203 Fax: 01203 440331 For your reference I am just completing a video on alternative solder finishes their advantages and disadvantages, assembly yields, solderability testing thickness assessment and how to get the best out of copper finishes. It will be available in the near future from SMTA, Electrovert and me in the UK. Further details can be provided if any one wants them. There are some things about copper boards on my Process FAQ's on my Home Page if you want to check it out. Bob Willis Home Page Http://ourworld.compuserve.com/homepages/bwillis