Hello Alexis,

IPC-2222 (rigid boards) para 10.1.1 refers to the minimum spacing to
non-plated through holes, 'shall not be less than the minimum spacing
specified in  Table 6-1 of IPC-2221 plus 0.4mm."
I usually consider the maximum possible area that the screw head / washer /
mounting post / boss will occupy on the board and add the minimum
electrical spacing to that. This maximum area should take into account the
positional tolerances of the mounting screws, and also the clearance 'slop'
of the washers (if conductive) and even the amount that the board itself's
position can vary due to the necessary clearance on the mounting holes for
the screws.

regards,

Phil.

At 15:22 2/10/00 -0700, you wrote:
>I am looking for the IPC recommended clearance of components/traces/vias
>to mounting holes with screws.
>I can't find it in IPC-2221; does someone out there know where it is?
>Thanks in advance for any guidance.
>
>
>********************
>Alexis Meehan
>PCB CAD Mgr.
>408-328-4595
>[log in to unmask]
>LuxN, Inc.
>570 Maude Court
>Sunnyvale, CA 94085
>"The Optical Renaissance Has
>Begun."
 >
 >
 >                 <http://www.luxn.com/>http://www.LuxN.com



Phil Dutton C.I.D.
Senior CAD Technician
IPC Certified Interconnect Designer

Tenix Defence Systems Pty Ltd
Systems Division - Adelaide
Second Avenue, Technology Park,
Mawson Lakes.  SOUTH AUSTRALIA  5095

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