Good day Technet: We have a small custom part made of brass that's tin plated with .0001 to .00025" of tin. When we attempt to solder a wire to this part, the solder flows up the side and stops at the top, where there is a sharp corner. Some of these solder joints appear to be cracked at the sharp corner. I'm assuming this is similar to the "weak knee" scenario, where the sharp corner has very thin plating that has an exposed intermetallic compound, which is unsolderable. My questions are: 1) what type (if any) of intermetallic compound would I expect with tin-plated brass? 2) what should I look for in the microsection? Thanks in advance, Jim Marsico Senior Engineer Production Engineering EDO Electronics Systems Group [log in to unmask] <mailto:[log in to unmask]> 631-595-5879 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------