CB

The condition that you have referenced is acceptable per IPC 
specifications.  IPC-RB-276  paragraph 3.8.2 states "Random extraneous 
copper in open areas, or spurs and nodules along conductor edges are 
sllowed, provided they do not reduce conductor spacing below that 
specified in Table 8."

Hope this helps.  If you need a copy of 276, you can contact our customer 
service department on X318

Regards
***************************************************
David W. Bergman, Technical Director
IPC
2215 Sanders Road
Northbrook, IL  60062-6135
708-509-9700 x340 Phone
708-509-9798 Fax
email  [log in to unmask]
***************************************************


On Thu, 14 Sep 1995 [log in to unmask] wrote:

> Visualize a relatively simple double-sided plated-thru-hole PWB made from
> .062 thick FR-4.  It could be a few square inches or a hundred.  There are
> many areas that do not have traces in them.  Further, visualize a few dots of
> metal that eluded the etching process in these non-functional, otherwise bare
> areas.  They might vary from a dot of .050" diameter to a line .050" x 1"
> long in a sea of open and otherwise etched clean FR-4.  The "unwanted" metal
> is firmly affixed to the board and easily passes the most rigorous tape test.
>  None of these pieces of metal reduces spacing between conductors in any way.
>  The PWB is otherwise totally functional with these items being cosmetic - -
> - however, in the board's final use it is hidden deep in the user's
> equipment.
> 
> Are these acceptable to IPC specifications?  Reference to specific specs and
> paragraphs would be appreciated.
> 
> Do the metal areas need to be removed?  If so, why and how?  If they are
> scraped off and the FR-4 surface is scratched, does it need any post
> treatment?
> 
>