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Ni/Au > Immersion Tin/Silver PCB finish

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#47914

Ni/Au > Immersion Tin/Silver PCB finish | 22 February, 2007

One of our customers that always was going for Ni/Au surface finish on RoHS PCB and our processs was adjusted for that, "whithout any problem". Recently they decided to switch to another surface finsh: PbFree HASL. What is that? Imersion tin/silver? The board is doublesided with only a few chips on the topside + a trough-hole socket (it must be selectivive solderd later on). On the secondary side only 2 SMT-connectors. We don't have the experiance of this type of surface finish. I can understand that they are looking for a cheaper way of buying their pcb:s but here comes the question: Is there anything from solderpaste-reflow to the selective soldering that we need to think about? BTW, We only have the selective soldering machine for RoHS, the wave soldering machine is for non RoHS. /Sincerly

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#47920

Ni/Au > Immersion Tin/Silver PCB finish | 22 February, 2007

This [ http://www.smtnet.com/library/index.cfm?fuseaction=view_article_html&file=no_hasl ] describes HASL [hot air solder leveling], as well as other common types of solderability protection. It goes on the discuss the impact of the use of these coatings on ICT [that you may or may not care about].

That article focused on SnPb HASL. Your customer chose a lead free HASL like: http://www.aimsolder.com/techarticles/No-Lead%20and%20Horizontal%20Hot%20Air%20Leveling.pdf

We have no relationship, nor receive benefit from the company referenced above.

Q1: Is there anything from solderpaste-reflow soldering that we need to think about? A1: From solderpaste-reflow standpoint, your new HASL boards will probably not have pads as flat as the boards with ENIG that you're used to processing. This will have impact below 20 pitch. Q2: Is there anything from the selective soldering that we need to think about? A2: No Q3: Is there anything from the hand soldering that we need to think about? A3: No

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#47936

Ni/Au > Immersion Tin/Silver PCB finish | 23 February, 2007

Many thanks, DaveF I learn something new every day. Sincerely,

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