Ian, There is an idiom in my language, saying something like: "A wise person is the one who learns from other's experience". And another one: "If you need an advise, ask the experienced person, not the expert". The problem is with the Ni itself. I didn't have personal experience with it, as I keep my soul away from gold in any type (we don't have even gold coins). I read about the Ni barrels problems from colleagues, and found some data on it in Tyco's site. Sorry - I don't have the references: It was quite some time ago, and I read the documents on-line and dropped the links. Regards Ofer Cohen Quality Assurance Manager Seabridge Ltd. -----Original Message----- From: FOX, Ian (York Rd) [mailto:[log in to unmask]] Sent: Wednesday, June 11, 2003 10:10 AM To: 'TechNet E-Mail Forum.'; 'Ofer Cohen' Subject: RE: [TN] LCC HASL and Immersion Silver Ofer, interested in your comments regarding failure of electroless Ni barrels. Are you saying that the stress applied by the press-fit termination causes failure or that simply the Ni itself fails? If it's the former I can't comment having only just started to look at press-fits seriously. If the latter then I have to say in my experience an electroless layer hangs on in there long after Cu beneath it has circumferentially cracked. Regards Ian Fox Goodrich Engine Control Systems -----Original Message----- From: Ofer Cohen [mailto:[log in to unmask]] Sent: 11 June 2003 07:25 To: [log in to unmask] Subject: Re: [TN] LCC HASL and Immersion Silver Peter, Although the question is to Dave, I will contribute my own 2 cents. Because I made the decision some time ago, I would be glad to hear (=read, in this case) comments. As long as the components were in the sizes down to minimum of 0402 for discrete components, and pitch of 1 mm for BGAs and 0.5 mm for other components I lived (and still do) happily with HASL. This is my preferable coating, because a) every PCB manufacturer does it best; b) the handling during the assembly and the assembly processes are simple and commonly known. The problems started when the army of the R&D people conquered the 0.8 mm pitch BGAs. I know that HASL is still acceptable in this pitch. However, the circuit is sensitive and I wanted to make it more robust. I considered 4 choices: a) immersion tin and OSP - problematic in handling. I have to trust my CM that even in the third shift the SMT line operators will wear clean gloves. I am a little paranoid about compliance of employees to procedures that are less comfortable to implement. Apart of it, I had bad experience with some PCB manufacturers performing this finish. b) ENIG - not to speak of black pads, I have many press-fit connectors, and the nickel layer is known to have long-term reliability problems in this case, because it cracks and causes disconnections. c) Immersion silver - was left alone and selected as default. Indeed, it needs some time to get used to it: the wetting is not perfect, handling and storage period are still have to be monitored. Yet, it seems to be the optimal solution. Yet, I want to emphasize that my default finish is HASL. Regards Ofer Cohen Quality Assurance Manager Seabridge Ltd. -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: Wednesday, June 11, 2003 1:52 AM To: [log in to unmask] Subject: Re: [TN] LCC HASL and Immersion Silver Hi, Dave, Can you shed a little more light in this dark world and give us the story of why you choose Immersion Silver over, say, Immsersion Tin for BGAs and Fine-Pitch stuff. I'm interested from the Class 3 High Reliability perspective and currently use ENIG for this type of assembly. For future designs, though, I intend to move to either ImAg or ImSn, but haven't determined which one yet. TIA Peter --------------------------------------------------- Technet Mail List provided as a free 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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------