I had heard that Immersion Silver finish will tarnish in approx. 6 months, so it isn't a good option for PCB's that will be stored for awhile. Did I hear correctly ?? Regards TDK -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Nutting Sent: Wednesday, March 30, 2005 6:30 AM To: [log in to unmask] Subject: Re: [TN] Lead free solder HAL Will there be a tarnish issue after long storage periods? Frequently we may order a few more boards than actually used and these would then sit on the stockroom shelf, typically not in a sealed bag. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jeffrey Bush Sent: Wednesday, March 30, 2005 8:04 AM To: [log in to unmask] Subject: Re: [TN] Lead free solder HAL Leadfree solders in PCB fabrication are more difficult to use than standard solders alloys and present problems in equipment and processing. I am sure you will here that it is something that can be done easily and many are doing it, but this is sales speak more than fabrication logic. I see the real winner in leadfree surface finish for PCB being immersion silver. This is where the majority of the development effort is going and as such the resulting products are becoming hardened for multiple thermal cycles at LF reflow and pot temperatures in the assembly processes. I see that some specific applications are valid for ENIG, Immersion Tin and some of the new OSP lines, but I believe silver will be the finish of choice. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Russell Burdick [mailto:[log in to unmask]] Sent: Wednesday, March 30, 2005 7:19 AM To: [log in to unmask] Subject: [TN] Lead free solder HAL Good Morning Technet, I am at the early stages of learning about lead free solder as an alternative option to our current tin/lead solder HASL. Is there anyone out there who can comment about their experiences? Currently I have no customers requesting this process, but I need to be ahead of this need when feasible. Vendors have provided both sides, yes PCB makers are doing it and a large PCB maker tried it and discontinued using it. Thanks in advance. Russ Burdick, trying to lessen the HASL hassle --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------