PCB holes overlapping

S

Spehro Pefhany

Guest
Is this generally acceptable? I want to overlap two of 0.136" holes by
about 0.024" in several places. They are plated with no electrical
function.

Thanks!

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in message
news:pdaq61hknm8ilg9tneud2i8hkkgjluckce@4ax.com...
Is this generally acceptable? I want to overlap two of 0.136" holes by
about 0.024" in several places. They are plated with no electrical
function.

Thanks!

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers:
http://www.trexon.com
Embedded software/hardware/analog Info for designers:
http://www.speff.com
Click to expand...

One supplier I use for prototype PCBs (PCB-Pool)assumes that overlapping
holes are slots to be routed. I don't think that PCB manufacturers would
like actual overlapping holes as they might break their drills.

Leon
--
Leon Heller
http://www.geocities.com/leon_heller
 
On Mon, 25 Apr 2005 14:01:24 -0400, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> wrote:

Is this generally acceptable? I want to overlap two of 0.136" holes by
about 0.024" in several places. They are plated with no electrical
function.

Thanks!

Best regards,
Spehro Pefhany
Click to expand...

Because the holes rather large compared to overlap you can probably get away
with it. Check with your board manufacturer.

--
Boris Mohar


Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca
 
Spehro,
Do you want a slot or a figure eight shape?

I always use one of either two methods for such things.
1) I use a unique hole size for one pad, 1 - 5mils, something
they cannot attempt to drill. Then do a note referencing that
drill size and a small drawing outlining the shape and dimensions
based upon the unique hole size being the center of one of your
lobes.
2) If it is a slot, then I usually use a mechanical layer to
draw the shape I want in the correct location and orientation.
Then reference it in your notes telling the fabricator that this
shape is desired and that it is plated. Make sure there is some
common reference between layers so that a Gerber set aligns the
detail precisely where you want it and in the correct orientation
on the PCB.
I have also give these details on multiple layers with the
lines actually including an offset for appropriate router bit
diameters that I know the fabricator has. Theses layers are then
just a router centerline path for them to program into their
machine.

--
Sincerely,
Brad Velander


"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in
message news:pdaq61hknm8ilg9tneud2i8hkkgjluckce@4ax.com...
Is this generally acceptable? I want to overlap two of 0.136"
holes by
about 0.024" in several places. They are plated with no
electrical
function.

Thanks!

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is
the reward"
speff@interlog.com Info for manufacturers:
http://www.trexon.com
Embedded software/hardware/analog Info for designers:
http://www.speff.com
Click to expand...
 
On Tue, 26 Apr 2005 05:25:09 GMT, the renowned "Brad Velander"
<SpamThis@nowhere.com> wrote:

Spehro,
Do you want a slot or a figure eight shape?
Click to expand...
Figure 8. I have 16 connectors with snap-in fingers on either side
that I need to mount as close together as practical.

I always use one of either two methods for such things.
1) I use a unique hole size for one pad, 1 - 5mils, something
they cannot attempt to drill. Then do a note referencing that
drill size and a small drawing outlining the shape and dimensions
based upon the unique hole size being the center of one of your
lobes.
Click to expand...
What's the advantage of that? To draw attention to it so that they
cannot "fix" it?

2) If it is a slot, then I usually use a mechanical layer to
draw the shape I want in the correct location and orientation.
Then reference it in your notes telling the fabricator that this
shape is desired and that it is plated. Make sure there is some
common reference between layers so that a Gerber set aligns the
detail precisely where you want it and in the correct orientation
on the PCB.
I have also give these details on multiple layers with the
lines actually including an offset for appropriate router bit
diameters that I know the fabricator has. Theses layers are then
just a router centerline path for them to program into their
machine.
Click to expand...

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
In article <pdaq61hknm8ilg9tneud2i8hkkgjluckce@4ax.com>, Spehro Pefhany
<speffSNIP@interlogDOTyou.knowwhat> writes
Is this generally acceptable? I want to overlap two of 0.136" holes by
about 0.024" in several places. They are plated with no electrical
function.
Hi Spehro,
Click to expand...

Yes totally acceptable at the size in question. I would be amazed if any
manufacturer found it a problem. Only side effect of the double drill
that I can think off would be the possibility of a few broken glass
fibres protruding where the two holes intersect.

--
Roger M Unwin
P+M Services (R) Ltd Tel : 01706 815212 Fax : 01706 818636
Http://www.p-m-services.co.uk
 
On Tue, 26 Apr 2005 20:21:59 +0100, the renowned Roger M Unwin
<Roger@p-m-services.co.uk> wrote:

In article <pdaq61hknm8ilg9tneud2i8hkkgjluckce@4ax.com>, Spehro Pefhany
speffSNIP@interlogDOTyou.knowwhat> writes
Is this generally acceptable? I want to overlap two of 0.136" holes by
about 0.024" in several places. They are plated with no electrical
function.
Hi Spehro,

Yes totally acceptable at the size in question. I would be amazed if any
manufacturer found it a problem. Only side effect of the double drill
that I can think off would be the possibility of a few broken glass
fibres protruding where the two holes intersect.
Click to expand...
Thanks! Out it goes. ;-)



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Spehro,
Yes the advantage is that it is a hole they just cannot drill
if they have missed it's true function through the notes. The use
of a hole also gives you (and them) one precise location relative
to the rest of the database.
So the figure 8 takes one snap in lead from two connectors
and you just wanted them close so that they broke into each
others holes? I am now wondering what type of connector your
talking about and if maybe a short slot on the other axis would
be better (a straight edge instead of the round edge). The
connector doesn't fit over the figure eight I would guess, unless
it doesn't connect electrically to the board at least.
--
Sincerely,
Brad Velander

"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in
message news:5c6s615lhaafjhdo2a0n5upqakqlogahdc@4ax.com...
On Tue, 26 Apr 2005 05:25:09 GMT, the renowned "Brad Velander"
SpamThis@nowhere.com> wrote:

Spehro,
Do you want a slot or a figure eight shape?

Figure 8. I have 16 connectors with snap-in fingers on either
side
that I need to mount as close together as practical.

I always use one of either two methods for such things.
1) I use a unique hole size for one pad, 1 - 5mils,
something
they cannot attempt to drill. Then do a note referencing that
drill size and a small drawing outlining the shape and
dimensions
based upon the unique hole size being the center of one of
your
lobes.

What's the advantage of that? To draw attention to it so that
they
cannot "fix" it?

Best regards,
Spehro Pefhany
Click to expand...
 
On Wed, 27 Apr 2005 03:46:12 GMT, the renowned "Brad Velander"
<SpamThis@nowhere.com> wrote:

Spehro,
Yes the advantage is that it is a hole they just cannot drill
if they have missed it's true function through the notes. The use
of a hole also gives you (and them) one precise location relative
to the rest of the database.
So the figure 8 takes one snap in lead from two connectors
and you just wanted them close so that they broke into each
others holes? I am now wondering what type of connector your
talking about and if maybe a short slot on the other axis would
be better (a straight edge instead of the round edge). The
connector doesn't fit over the figure eight I would guess, unless
it doesn't connect electrically to the board at least.
Click to expand...
It doesn't connect electrically (plastic snaps), and the legs are not
round, they are rectangular. Ideally slots would be punched, but the
volume isn't there.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
 
Spehro,
Yeah, I was suspicious that the round holes probably weren't
the optimum hole for anything that snapped in. Simply because
most snap in parts would only fully catch at the outside corners
rather than along the full length of the snap face.
Would short routed slots not be better? Slightly longer than
the length of the snap face. Then the whole face of the snap
feature can bear the loading instead of just the corners.
Typically you can get 0.032", 0.625" or 0.093" routing diameters
from most fabricators. Other sizes would not be as common, even
0.032" is not so common with a lot of them.

--
Sincerely,
Brad Velander

"Spehro Pefhany" <speffSNIP@interlogDOTyou.knowwhat> wrote in
message news:n04v61lo6i4efuoj59og163rtkrqs1qru0@4ax.com...
On Wed, 27 Apr 2005 03:46:12 GMT, the renowned "Brad Velander"

It doesn't connect electrically (plastic snaps), and the legs
are not
round, they are rectangular. Ideally slots would be punched,
but the
volume isn't there.


Best regards,
Spehro Pefhany
Click to expand...
 
On Thu, 28 Apr 2005 04:41:26 GMT, the renowned "Brad Velander"
<SpamThis@nowhere.com> wrote:

Spehro,
Yeah, I was suspicious that the round holes probably weren't
the optimum hole for anything that snapped in. Simply because
most snap in parts would only fully catch at the outside corners
rather than along the full length of the snap face.
Would short routed slots not be better? Slightly longer than
the length of the snap face. Then the whole face of the snap
feature can bear the loading instead of just the corners.
Typically you can get 0.032", 0.625" or 0.093" routing diameters
from most fabricators. Other sizes would not be as common, even
0.032" is not so common with a lot of them.
Click to expand...
That's a very good idea. I'll ask when the final revision is done.

Thanks!


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