Electronics Forum | Wed Aug 09 08:06:07 EDT 2006 | davef
See "IPC-4554 Specification for Immersion Tin Plating for Printed Circuit Boards" 3.2.1 Immersion Tin Thickness. The most common reason for solderability issues with the white tin surface coating during multiple thermal excursions is a thin white ti
Electronics Forum | Wed Aug 04 16:49:24 EDT 2004 | jim_bob
Regarding Lead Free component finishes, vendors are zeroing in on matte tin plating as the finish of choice. What test are performed, to determine if a finish is "matte" type (vs. non-matte)?
Electronics Forum | Fri Dec 16 08:16:41 EST 2005 | davef
Heat cycles deplete the pure tin layer. Each solder cycle reduces the tin thickness by ~0.1 micron (4 uin). So, if you start with a thin imm tin coating you'll have problems after multiple heat cycles. Steve Wentz says, "In almost every case I've
Electronics Forum | Fri Jun 14 14:30:36 EDT 2002 | davef
Assuming you are talking about solderable surfaces: People specify various materials to protect the solderability of the pads on the board. Gold, actually, Electroless Nickel - Immersion Gold [ENIG], is popular. * Board fabricators like it because
Electronics Forum | Wed Sep 19 16:02:14 EDT 2001 | fcouture
Pad Metallurgy Used: >Is your question about this targeting the current industry capability of using tin plating technology on such small >pad dimensions? Actually I should have asked for tin/lead plating (HASL) and yes it's to have an idea on capab
Electronics Forum | Tue Sep 18 13:21:06 EDT 2001 | fcouture
Hello Jeff, I found some good information from what I read until now...so thank you! I have two questions: 1) What finish did you use on the PCB for 0201 ? I think with an aperture so small (12x15mils) tin plated is impossible, what do you think
Electronics Forum | Wed Sep 19 14:23:31 EDT 2001 | jschake
Pad Metallurgy Used: Copper OSP pads were used for all of the results that I have been reporting. The same design test boards with Nickel/Gold pads are available and awaiting further assembly tests. I will consult with a board technology and metall
Electronics Forum | Mon Nov 25 15:55:32 EST 2002 | davef
Sorry, no tricks for you. The good news is: your reflow recipe should be similar for both imm tin and HASL. Imm tin requires more attention to detail by both the fabricator and the assembler than HASL. There is a fair amount of discussion on imm
Electronics Forum | Fri Jun 17 10:47:48 EDT 2005 | davef
Doug: We agree that imm tin can be easily stripped and reapplied. Do you order imm tin as bright/ dull? Is bright/dull a function of who the fabricator lisences the process? Er wha? Electroplate tin can be either matt or bright. It is different
Electronics Forum | Fri Aug 08 08:00:46 EDT 2003 | davef
Matt: You're correct. Do not mess with these boards. If the immersion tin [imm tin] is discolored, it will not solder with routine processes. Ask your customer to return the boards to his / her fabricator and have the imm tin replated. The fabri
