Rick

pending the environment thermal fluctuation your customer is doomed in field
:
also the intermetalics build up over time ; making it a real warranty race
if somebody chooses (like your customer) to design that way

As for the standards and recommendations on flash I found most sensible
ITRI's 1.5 um limit (micrometer ; converting to metric all the time ; you
have some 40u"to 1um) :
check : http://www.itri.co.uk/index.htm ; if I got it right .
We keep internal usual 0.3 - 0.5 um ; with 0.8 um inwards limit ; with some
6 months old boards average = no Ni oxide problem .
The results on IPC-SM-785 reliability cycling were very good (bloody
excellent to be frank, with indium NC-SMQ90[dispensing]) ; keep low on
reflow peak .

Somebody may correct me ; but I could not find IPC's equivalent on flash
recommendation .

See you

Paul Klasek
http://www.resmed.com

> ----------
> From:         Rick Thompson[SMTP:[log in to unmask]]
> Sent:         Friday, 29 January 1999 10:48
> To:   [log in to unmask]
> Subject:      [TN] Gold Flash Spec for PCB?
>
> <<File: Rick Thompson.vcf>>
> Hi,
>
> Can someone recommend IPC or other specs that deal with thickness
> specifications for gold flash and/or plating on PCBs? Any other sources of
> information or recommendations would be appreciated as well.  I have a
> customer who needs plated gold for wire bonding but in the interest of
> saving money, they've elected to have the entire PCB plated with 80-100
> microinches of gold. This is causing us alot of problems with solder joint
> quality in terms of brittleness of the joints. I'm trying to offer them
> some
> alternatives, but am not that familiar with what's considered "standard".
> Any insight would be greatly appreciated.
>
> Thanks.
>
>
> Rick Thompson
> Ventura Electronics Assembly
> 2665A Park Center Dr.
> Simi Valley, CA 93065
>
> +1 (805) 584-9858 voice
> +1 (805) 584-1529 fax
> [log in to unmask]
>

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