A likely place for that requirement is in IPC-A-6012, which is
Qualification and Performance Specification for Rigid Boards.
but...
the only thing I see about that, is in paragraph 3.5.4.6
Final Finish Coverage
"Final finish shall meet the solderability requirements of
J-STD-003. Exposed copper on areas not to be soldered
is permitted on 1% of the conductor surfaces for Class 3
and 5% of the surfaces for Class 1 and 2. COVERAGE
DOES NOT APPLY TO VERTICAL CONDUCTOR EDGES."
So, unless there is another reference,
(oh no, side rant approaching....
How can we get IPC to publish a searchable index of ALL
specs, and then search ALL for "EXPOSED COPPER"?
that would be an AWESOME technology to use, but its
only been around since the 1970s, and we're not "early
adopters". But hey, If the index showed him which spec
to BUY, then we wouldn't be transcribing this copyrighted
material on public forums.
INCREASED SALES! HUH? HUH?
....side rant concluded)
then maybe you don't have to worry about it.
If you learn more somewhere else, please share it with us, ok?
good luck,
Jack
On 5/29/07, Gary Bremer <[log in to unmask]> wrote:
>
> Where is it stated that the conductive pattern can not have any exposed
> copper on the vertical surfaces? Is that any empirical data that supports
> a
> failure mode if there is exposed copper on the vertical surfaces of a
> conductive pattern? I have searched MIL-STD-2000, NASA-STD-8739-2 and
> NASA-STD-8739-3 but can only find that it is allowed. Where I work those
> with PhD's worry about exposed copper on the vertical edges of the
> conductive patterns and are scared to allow to move forward because of
> possible failure modes with a deep space launch. For my limited knowledge
> of
> metallurgy: after copper is exposed to moisture and oxygen, corrosion
> takes
> place only on the surface and does not migrate any further. I do have
> access
> to NHB5300 to see if exposed copper was not allowed.
>
>
> Gary Bremer
>
> _________________________________________________________________
> PC Magazine's 2007 editors' choice for best Web mail—award-winning Windows
> Live Hotmail.
>
> http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507
>
>
> ---------------------------------------------------------------------------------
> DesignerCouncil Mail List provided as a free service by IPC using LISTSERV
> 1.8d
> To unsubscribe, send a message to [log in to unmask] with following text in
> the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
> To temporarily stop/(restart) delivery of DesignerCouncil send: SET
> DesignerCouncil NOMAIL/(MAIL)
> Search previous postings at: www.ipc.org > On-Line Resources & Databases >
> E-mail Archives
> Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16for additional information, or contact Keach Sasamori at
> [log in to unmask] or 847-615-7100 ext.2815
>
> ---------------------------------------------------------------------------------
>
---------------------------------------------------------------------------------
DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL)
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
---------------------------------------------------------------------------------
|
