Here is some information on how to design PTH and SMT circuit boards for efficient manufacturing and testing. There are also some guidelines on selecting and placing components. I have looked for this sort of information on the web in the past, and haven't found a lot. There is some good info here, and references to where to look for more. PDF @ http://www.aimtronics.com/DFMDecember2000.pdf Lyle Killough -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body