At 01:50 PM 8/17/2005, Brad Kosiance wrote:
I converted a two layer PBC to a 4 layer PCB.... The vias are 28/40 mils.
The PCB manufacturer is okay with 6 mil annular ring on the top and bottom
layers but requires 8 mil on the internal layers.
Must the vias be replaced with pads to achieve this? If so can all the vias
be replaced with pads globally or do they have to be replaced manually?
Protel 99SE.
Not enough information to give a complete answer..... As Mr. Saputelli
pointed out, you can globally edit the vias to become 24/40. That's usually
considered easily manufacturable nowadays.
However, what if you want to keep the holes at 28 mils for some reason? And
you need to keep the top vias at 40 mils, you can't expand them.
I'm trying to remember if 99SE allows different via pads by layer (i.e., a
"padstack). If not, then, yes, a simple solution would be to replace the
vias with free pads. A "free pad" is really quite the same as a via, except
that you can do more things with it. You can name it, for example, and then
do global edits on these "vias" by name.
There is a Convert Tool in 99SE that can be used to convert selected vias
to pads. The pads will have the same sizes as the vias had. And they will
at this point all be selected. You can then globally edit them to give them
all a name. I'd suggest "VIA." You might find it useful later. And then you
can edit them, keying on the name, to have different pads in the inner
layers. Of course, if you do this, you will be removing 2 mils from any
pad/track gaps on those layers. If that's okay, then you are done.
But simply going to 24/40 is probably the simplest solution unless there is
a reason not to do it.
____________________________________________________________
You are subscribed to the PEDA discussion forum
To Post messages:
mailto:[email protected]
Unsubscribe and Other Options:
http://techservinc.com/mailman/listinfo/peda_techservinc.com
Browse or Search Old Archives (2001-2004):
http://www.mail-archive.com/[email protected]
Browse or Search Current Archives (2004-Current):
http://www.mail-archive.com/[email protected]
