Pad Sizes For Single Sided Boards?

[RichardD]

Does any one know if IPC recommend a size of annular rings for pads
when used on Single Sided Boards. I know that they should be larger
than used for double sided and multilayer boards.

 

[Simon Peacock]

IPC are too high tech for this.. For single sided boards.. ALAP.. thats as
large as possible.
consider 80 mil pads on a 100 mil pitch.. or even go for an 80 x 100 oval
pad (or larger). If you are planning to rework it is important as the pads
will tend top become unglued very easily. I also turn on the fillets so
that the traces come out of pads with the most copper possible. Minimum
trace / clearance .. 20 mil / 20 mil too

oh.. of course 80 mil means no tracks between pads but the resulting board
can be worked easier

Simon

"RichardD" <richard.durrant@baesystems.com> wrote in message
news:5f37a492.0309170240.5adb1a0a@posting.google.com...

Does any one know if IPC recommend a size of annular rings for pads
when used on Single Sided Boards. I know that they should be larger
than used for double sided and multilayer boards.

 

[Spehro Pefhany]

On Thu, 18 Sep 2003 19:02:52 +1200, the renowned "Simon Peacock"
<nowhere@to.be.found> wrote:

IPC are too high tech for this.. For single sided boards.. ALAP.. thats as
large as possible.
consider 80 mil pads on a 100 mil pitch.. or even go for an 80 x 100 oval
pad (or larger). If you are planning to rework it is important as the pads
will tend top become unglued very easily. I also turn on the fillets so
that the traces come out of pads with the most copper possible. Minimum
trace / clearance .. 20 mil / 20 mil too

oh.. of course 80 mil means no tracks between pads but the resulting board
can be worked easier

For 100 mil pitch, DIPs, etc, you can use pads that are oblong, sort
of like this: (fixed width font)...

--------------
/ . \
| ( ) |
\ - /
---------------

... and shave down the edges of only those pads that have to have
traces run between them.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
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