At Caterpillar:
for .062 - one mount every 3 inches minimum (usually 2.5inches)
for .093 - one mount every 4 inches minimum

This is not based on any standard or scientific study (sorry)
but it is fairly consistent with what I've seen at previous jobs.

good luck,
Jack





Matthew Lamkin <[log in to unmask]>@IPC.ORG>
15Apr2002 07:08 AM

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Subject:  [DC] SMT board mounting holes - distances between query?
Retain Until: 05/15/2002 Retention Category: G90 - Information and Reports
Caterpillar Confidential:  Green


Hello
The point has been raised with me, at what distance would the recommended
maximum dimension
be between mounting holes for a board that contains SMT components, so as
not to damage
the components or joints when the board is flexed/moved etc ?
Especially where there may be a connector or button/switch that may be
pushed.

generally speaking this would be for square/rectangular FR4 1.6mm boards,
with 4mm mounting holes
on pillars. I know that there is a great deal of variation due to different
shapes and fixings etc, but I'm after a
recommendation to create a basis of a company standard from.

Is there anything in any of the IPC standards?
Or what would you suggest?

Any comments welcome....
Matthew Lamkin
Printed Circuit Board Draughtsman
Research & Development Dept.
Protec Fire Detection PLC.
Churchill Way,
Nelson, Lancashire,
England. U.K.

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