Interesting George, is that a std among board makers or do you have to imply that method in your own Incoming Inspection? In the later example it's too late, the boards are already delivered, so I assume it's something one has to perform immediately before final plating. My question: is there a corresponding inspection method for judging nickel solderability before gold immersion is put on? I talk for ENIG of course. There are many soaps that react with nickel but using a std method would be best. Wetting balance on test coupons will probably not tell the whole truth. Ingemar Hernefjord Ericsson Microwave System The primary advantage of IAg is that it changes the color of the copper pad. OSP doesn't change the color of the copper pad. We use IAg not as a solderable surface finish; we use IAg as a visual inspection aid to know that the underlying copper is solderable (i.e., if the copper changes color because the silver plated on it we know that the board fabrication process didn't leave any residue such as solder mask or incomplete tin strip on the pad that won't show up until you commit expensive components at assembly. Regards, George George M. Wenger, DMTS Bell Laboratories Princeton Supply Network Solutions PO Box 900, Princeton NJ 08542-0900 Route 569 Carter Rd., Hopewell, NJ 08525 (609)-639-2769 (Office), 3210 (Lab), 2343 (Fax) [log in to unmask] -----Original Message----- From: Michael Forrester [mailto:[log in to unmask]] Sent: Wednesday, January 24, 2001 10:51 AM To: [log in to unmask] Subject: [TN] Silver vs OSP surface finish What are the advantages of using Silver (Alpha level) Vs OSP (Entek) as a surface finish? Since Alpha level has an OSP over the silver why bother with the silver? Wouldn't less interfaces between the component and trace be better? Thank you. Best Regards, Michael Forrester LeCroy Corp. ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------