What is correct method?

[Ivan]

For general reference, if there is an instance where certain mounting
holes should be part of a chassis ground net, is it proper to give
them a part number and include them in the schematic, or is it ok to
just electrically connect them on the PCB side with no record of them
in either schematic or PCB netlist?

Thank you,

Ivan

 

[Joerg]

Hello Ivan,

Mostly I have seen that being a part of the mechanical drawing set and
assembly instructions. Please mind that it is often not allowed to
employ a mechanical load point as a safety ground point. IOW, you
usually need a separate stud for that and this stud shall not be load
bearing.

Regards, Joerg

http://www.analogconsultants.com

 

[qrk]

On Thu, 17 Mar 2005 15:43:31 -0500, Ivan <ivanzr1@aol.com> wrote:

For general reference, if there is an instance where certain mounting
holes should be part of a chassis ground net, is it proper to give
them a part number and include them in the schematic, or is it ok to
just electrically connect them on the PCB side with no record of them
in either schematic or PCB netlist?

Thank you,

Ivan

Make a schematic part and connect it properly in the schematic. The
DRC will be happy with this technique. Plus, when you hand out the
project for someone else to do the layout work, there is no question
what to do with this mounting hole.

Mark

 

[Gary Crowell / VCP]

On Thu, 17 Mar 2005 21:36:05 -0800, qrk <SpamTrap@reson.com> wrote:

On Thu, 17 Mar 2005 15:43:31 -0500, Ivan <ivanzr1@aol.com> wrote:

For general reference, if there is an instance where certain mounting
holes should be part of a chassis ground net, is it proper to give
them a part number and include them in the schematic, or is it ok to
just electrically connect them on the PCB side with no record of them
in either schematic or PCB netlist?

Thank you,

Ivan

Make a schematic part and connect it properly in the schematic. The
DRC will be happy with this technique. Plus, when you hand out the
project for someone else to do the layout work, there is no question
what to do with this mounting hole.

Mark

Absolutely agree. Its an excellent idea to have a library of mounting
hole components (even for those that are not connected to a net - then
they show, correctly, as no connects). In some systems you can set
an attribute (I call mine NBI), to indicate that the 'component' is
not to be listed on the BOM.

Gary Crowell, CID
Micron Technology

 

[Brad Velander]

I third the comments from Gary and qrk. It is just much
cleaner and less prone to somehow/someone leaving those mounting
points unconnected regardless of where they connect. They are
part of the electrical design and therefore need to be defined,
constrained and controlled, usually within the schematic.

--
Sincerely,
Brad Velander

"Gary Crowell / VCP" <vcp@cableone.net> wrote in message
news:i69n31l0smrhhlr2cuk7kbcpv74lj1q4bh@4ax.com...

On Thu, 17 Mar 2005 21:36:05 -0800, qrk <SpamTrap@reson.com
wrote:

On Thu, 17 Mar 2005 15:43:31 -0500, Ivan <ivanzr1@aol.com
wrote:

For general reference, if there is an instance where certain
mounting
holes should be part of a chassis ground net, is it proper to
give
them a part number and include them in the schematic, or is
it ok to
just electrically connect them on the PCB side with no record
of them
in either schematic or PCB netlist?

Thank you,

Ivan

Make a schematic part and connect it properly in the
schematic. The
DRC will be happy with this technique. Plus, when you hand out
the
project for someone else to do the layout work, there is no
question
what to do with this mounting hole.

Mark

Absolutely agree. Its an excellent idea to have a library of
mounting
hole components (even for those that are not connected to a
net - then
they show, correctly, as no connects). In some systems you
can set
an attribute (I call mine NBI), to indicate that the
'component' is
not to be listed on the BOM.

Gary Crowell, CID
Micron Technology