Hi Murray - LOL, it is interesting that most folks, including myself, read
"15 microinches" and not the "15 inches" you actually put in the paragraph.
Doug is a pretty savvy proof reader so he caught it!
Dave
On Fri, Jan 3, 2020 at 3:53 PM Campbell, Murray <[log in to unmask]>
wrote:
> Haha, I'll take the 15inches of gold off at incoming inspection and put it
> towards my retirement! Apparently it didn’t like my micro symbol, how
> about 15 micro inches
>
>
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Douglas Pauls
> Sent: Friday, January 3, 2020 2:48 PM
> To: [log in to unmask]
> Subject: Re: [TN] [External] [TN] immersion gold thickness
>
> Ya gotta wonder how long it takes to plate up 15 INCHES of gold......
>
> *Douglas Pauls *| Principal Materials and Process Engr | Advanced
> Operations Engineering
>
> *COLLINS AEROSPACE*
>
> 400 Collins Road NE, MS 108-101, Cedar Rapids, IA 52498 USA
>
> *Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773
>
> [log in to unmask]
>
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>
> On Fri, Jan 3, 2020 at 3:45 PM David Hillman <
> [log in to unmask]> wrote:
>
> > Hi Murray - if you can get a true ENIG plating chemistry to put 15
> > inches of gold thickness on a board, you would never want to use the
> > board as the gold plating would have severe structure and/or
> > solderability issues. The IPC-4552 specification contains the industry
> > consensus gold plating thickness range that applies to producing an
> > acceptable and reliable ENIG plating layer. Any gold plating thickness
> > outside of that range would be questionable at best for quality and
> > reliability unless you are working closely with a plating chemistry
> > supplier who is doing a custom plating bath composition. One of the
> > early issues of ENIG plating was the industry asking the plating
> > chemistry suppliers to provide an immersion gold plating thickness
> > that exceeded the acceptable physics of the plating chemistry (basically
> this is how we discovered "black pad"!).
> >
> > Dave Hillman
> > Collins Aerospace
> > [log in to unmask]
> >
> > On Fri, Jan 3, 2020 at 3:30 PM Campbell, Murray
> > <[log in to unmask]>
> > wrote:
> >
> > > Happy New Year All,
> > >
> > > Is there any good reason to call out a maximum gold thickness /
> > > nickel thickness on fab notes or is it sufficient to rely on simply
> > > stating that the fabricator shall follow ipc-4552 minimum thickness?
> > > I have seen some companies state that a maximum thickness upwards of
> > > 15 µin to be acceptable. Is there any value in stating an upper range?
> > > I know it states in 4552 that an upper range had been debated and
> > > not necessary but I still see an upper added to fab notes.
> > >
> > > Regards,
> > >
> > > Murray Campbell
> > > PCB Design Specialist
> > > [log in to unmask]<mailto:[log in to unmask]>
> > > [cid:[log in to unmask]]
> > >
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