Patric
In this case, where the surface already came into contact with solder and dewetted an IMC has formed or was already present. Such a surface can never be soldered. In the best case you are able to cover the surface with solder because there are most probably islands of solder left on the IMC and with hand- soldering you might convince a drop of solder to adhere on the surface but this is never a solder joint.
I believe in this case the HASL was very thin and the PCB has been stored for some months at room temperature or a shorter time at higher temperature (some hours at 80°C in a container during transport) to allow the IMC to grow through the plating.
Best regards
Günter
.
> -----Ursprüngliche Nachricht-----
> Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Patrick Goodyear
> Gesendet: Mittwoch, 2. Oktober 2013 07:40
> An: [log in to unmask]
> Betreff: Re: [TN] HASL question
>
> I don't have any experience on this but based on the pictures I think I would
> attempt to reflow by hand to see what is needed to make it work, that might
> lead to a clue as what is not right.
>
> pat
>
>
> On Tue, Oct 1, 2013 at 4:23 PM, Steve Gregory wrote:
>
> > Hi Bob,
> >
> > It's supposed to be, but I have my doubts...
> >
> > Steve
> > -----Original Message-----
> > From: Bob Landman [mailto:[log in to unmask]] Sent: Tuesday,
> > October 1, 2013 5:22 PM
> > To: TechNet E-Mail Forum; Steve Gregory
> > Subject: Re: [TN] HASL question
> >
> > Steve,
> > It looks like nice shiny nickel...
> >
> > Is this a lead-free HASL?
> >
> > Bob
> >
> > Sent from my iPhone
> >
> > On Oct 1, 2013, at 7:14 PM, Steve Gregory <[log in to unmask]> wrote:
> >
> >> Okay here's another picture. I printed a solder sample and sent it
> >> through the oven and this is what it looked like:
> >>
> >> http://stevezeva.homestead.com/SolderSample.jpg
> >>
> >> You can see all the non-wetting going on. The board was profiled and
> >> it was fine. We are using a FCT Assembly WS889 SN100C solder paste.
> >>
> >> What is even more strange is that the first side of the board looked
> >> okay, but the second side looks like in the photos, like the problem
> >> is confined to one side of the board if that's possible.
> >>
> >> The solder sample was only reflowed once, but I printed the paste on
> >> the side that was to be built last. Weird huh?
> >>
> >> I know you can't tell anything for sure just from some photos, but
> >> it's the strangest thing I've seen in a while...
> >>
> >> Steve
> >>
> >> -----Original Message-----
> >> From: Steve Gregory
> >> Sent: Tuesday, October 1, 2013 4:46 PM
> >> To: [log in to unmask]; Steve Gregory
> >> Subject: RE: [TN] HASL question
> >>
> >> Here's one picture:
> >>
> >> http://stevezeva.homestead.com/NonWetting.jpg
> >>
> >> Look at the left pad and the tarnish that you see there, does that
> >> look like tarnished nickel?
> >>
> >> This is after the board was washed. I have places all over the board
> >> that looks like this.
> >>
> >> I'll post a picture of what it looks like after I printed a solder
> >> sample with paste and sent it through the reflow over
> >>
> >> Steve
> >>
> >>
> >> -----Original Message-----
> >> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
> >> Sent: Tuesday, October 1, 2013 4:16 PM
> >> To: [log in to unmask]
> >> Subject: Re: [TN] HASL question
> >>
> >> Ahhhh....it's what I figured. I think that's what happened. I'll have
> >> pictures later.
> >>
> >> Steve
> >>
> >> -----Original Message-----
> >> From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer
> >> Sent: Tuesday, October 1, 2013 4:15 PM
> >> To: [log in to unmask]
> >> Subject: Re: [TN] HASL question
> >>
> >> No. Not unless somebody screwed up.
> >>
> >> -----Original Message-----
> >> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
> >> Sent: Tuesday, October 01, 2013 6:11 PM
> >> To: [log in to unmask]
> >> Subject: Re: [TN] HASL question
> >>
> >> Hi all,
> >>
> >> It's funny that the HASL topic has come up today, because we just ran
> >> a board today that supposedly was lead-free HASL finished, and man it
> >> looks like crap!
> >>
> >> Question; does a PCB get nickel before it gets Lead-free HASL'ed?
> >>
> >> Steve
> >>
> >> -----Original Message-----
> >> From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev.
> >> PhD
> >> Sent: Tuesday, October 1, 2013 2:23 PM
> >> To: [log in to unmask]
> >> Subject: Re: [TN] HASL question
> >>
> >> Hello Victor,
> >>
> >> It wouldn't solder in a first palce.
> >> --
> >> Best regards,
> >>
> >> Vladimir Igoshev. PhD
> >> mailto:[log in to unmask]
> >>
> >> SENTEC Testing Laboratory Inc.
> >> 11 Canadian Road, Unit 7.
> >> Scarborough, ON M1R 5G1
> >> Tel: (416) 899-1882
> >> Fax: (905) 882-8812
> >> www.sentec.ca
> >>
> >>
> >>
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