Electroless Nickel Immersion Gold The copper tracks are plated with nickel (no more than say 5 microns - sorry don't do micro inches - and then the nickel is protected by a thin layer of gold. (usually less than a micron say 0.5u) Best regards Mike Fenner Applications Engineer, European Operations Indium Corporation T: + 44 1908 580 400 M: + 44 7810 526 317 F: + 44 1908 580 411 E: [log in to unmask] W: www.indium.com Leadfree: www.Pb-Free.com -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Louis, Edwin @ CSE Sent: Wednesday, September 26, 2001 1:34 PM To: [log in to unmask] Subject: Re: [TN] White Immersion Tin What is ENIG.? -----Original Message----- From: Steve Kelly [mailto:[log in to unmask]] Sent: Tuesday, September 25, 2001 3:49 PM To: [log in to unmask] Subject: Re: [TN] White Immersion Tin I apologize to the Tech-net - I inadvertently sent out the wrong e-mail. I can add some feedback on immersion tin. We have neen running for over 2 years. The process does give a very good flat solderable surface and is a much easier process to control than ENIG. However it is very aggressive on soldermasks and dislikes thermals. We even silkscreen before we put down the immersion tin so we have the freshest surface available for soldering. Regards Steve Kelly -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Neil Atkinson Sent: Tuesday, September 25, 2001 3:48 AM To: [log in to unmask] Subject: Re: [TN] White Immersion Tin The advantages and disadvantages of immersion tin have been well covered in the TechNet in the past so it may be worth checking the archives. Anyway, for what it's worth here's what I have found with experience / what I have heard. Key advantages are it is flat, relatively cheap, easy process to install and control and, in my experience gives reasonable solderability even after storage provided the boards are reasonably well packaged. As for disadvantages, I have seen instances where the chemistry used for the immersion tin has attacked the solder resist and exposed copper, I'm not sure how environmentally friendly the chemistry is (although I am sure someone will now answer this!!). Overall, it depends what you want, no doubt someone will say ignore it and go for NiAu or HASL but I would say that it is a good general alternative to HASL and even in some cases NiAu (e.g. can carbon be used for any contacts?). If you haven't tried it I would say try it and use it where the price / performance ratio seems to be in favour of it. It does not suffer from whisker growth because it's structure is such that it reduces stresses in the material which cause growth (apparently!!). However, one question which I would ask is if anyone knows whether if white tin is put under mechanical stress e.g. by use of press fit connectors, can it then produce tin whiskers? One problem I have seen is with tin being slivers being produced by press-fit connectors resulting in shorts. Neil Neil Atkinson - Quality Manager Stadium Electronic Controls Division Stephen House, Brenda Road, Hartlepool (UK) TS25 2BQ -----Original Message----- From: Louis, Edwin @ CSE [mailto:[log in to unmask]] Sent: 24 September 2001 14:49 Subject: White Immersion Tin What are the advantages and disadvantages of Whit Immersion Tin for PCBs? Are there dendritic growth possibilities? What thickness minimum should you have? ############################################################################ ######### Attention: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please immediately delete it and all copies of it from your system, destroy any hard copies of it securely and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. STADIUM GROUP PLC and any of its subsidiaries each reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorised to state them to be the views of Stadium Group Plc. or one of its subsidiaries. Although this message has been scanned by MailMarshall for known viruses and inappropriate content, we recommend that recipients employ appropriate measures on their systems to intercept any such material. Thank You - Stadium Group Plc., IT Department - Tel: +44 (0)1429 266544 ############################################################################ ######### ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------