Hi Gaby! Just like Christmas! You got not only tin whiskers but poor
solderability and zincification! Can you shoot a photograph for Steve G. to
post on his website?
Dave
Gabriela Bogdan
<gabriela@NETVISI
ON.NET.IL> To
Sent by: TechNet [log in to unmask]
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Subject
01/27/2005 10:52 Re: [TN] Solder tags and tin
AM thickness
Please respond to
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; Please respond
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Gabriela Bogdan
<gabriela@NETVISI
ON.NET.IL>
Today I got from one of our new customers a bag wuth brass tags
electroplated with BRIGHT tin , NO UNDERPLATING, age 6 months, with very
poor solderability.
Observatin under microscope- not only pitting, but little mounds of tin
and-of course-I am always the lucky one- WHISKERS which could be
photographed easily under a zoom microscope. Ain't I lucky???
Gaby
----- Original Message -----
From: "Ingemar Hernefjord (KC/EMW)" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, January 27, 2005 6:21 PM
Subject: Re: [TN] Solder tags and tin thickness
> Dave,
> you were very close to the truth! We have experienced exactly what you
mention. Had to skip whole lot of parts, because they were only partly
solderable. I'll send a pic offline to you. The zincificaion brotherhood..
>
> The manufacturers of these tiny things do not seem to take nickel so
serious as you and I, because many of them just specify tin over brass.
>
> I like both english breakfast and american. I must admit, that I was
little bit in doubt about the US early meal appropriateness first time I
sat
down beside a guy in a typical tramlike bar in Syracuse. Time was about
half
past six in the morning, I was still halfsleeping, and that guy was digging
in a huge stack of pancakes. He drowned the pancakes in syrup and down
they
went. Then he ordered another stack and ended up with donuts and Coke. Now
I
make them myself, but use strong english coffee instead of Coke. Dual
influence, so as to say.
>
> Ingemar
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]]
> Sent: den 27 januari 2005 14:37
> To: [log in to unmask]
> Subject: Re: [TN] Solder tags and tin thickness
>
>
> Hi Ingemar! Don't forget that if you don't use a barrier metal between
the
> solder joint and the brass pin you have a chance of the solder joint
> integrity being questionable due to "zincification". Zinc from the brass
> can potentially diffusion into the solder joint causing problems. Either
a
> nickel or a copper barrier plating of the brass pin will eliminate the
> phenomena.
>
> Oh, an alternative American breakfast would be Diet Coke and a Snickers
or
> Doug's Mt. Dew and a bagel. Remember I said alternative, not healthy!
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
>
>
> Morning all, what about a simple q while melting first meal of the day?
> (US:donuts and coffee ; UK:scrambled eggs, black pudding, sausage,
> marmelade, plums,juice, milk, scones, bacon, coffee, cheese, tomatoes,
etc)
>
> Solder tags, pin, eyelets for printed boards, pressfit. We have found
large
> variations in tin thickness from various manufacturers. Checked about 20
> known makers, and none specified exactly what plating they had. Just
> 'tinned brass' or 'special high quality tin process' or 'solderable
> plating' etc. Too thin tin will make the pins less solderable after some
> months, while exaggerated thickness will cost some extra and cause
> tolerance problems. So, gentlemen, what do you prefer for a Veroboard
pin
> or a backplane ditto? I've proposed minimum 10 microns over nickel if the
> pins are brass. Or minimum 25 microns of tin without nickel barrier. Does
> this sound reasonable?
>
> Ingemar Hernefjord
> Ericsson Microwave Systems
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