Tim,
        I have done this many times and here is my methodology which
typically relies on the fact that I use full fab drawings for production
boards. For prototypes I will usually use a similar methodology which may
simply rely on readme details or a gerber output layer that showers the
extents of the slot/rectangle with respect to the board and the drill hole
location. I may (recently I usually do it) also include the outline of the
slot/rectangle on my board outline layer.

        I will use a pad (shape/size) doesn't really matter unless the
slot/rectangle is to be plated. If it is to be plated then the pad shape
will match the slot/rectangle shape plus the minimum annular ring width. The
hole will be specified as 1 mil (can't be fab'ed). I will have a note and
detail in the fab drawing which references the 1 mil drill size. The detail
will dimension and orient the cutout to the center of the drill. If there
are more than one slot/rectangle then I will use 2mil, 3mil, 4 mil drills
sequentially as needed, all with notes and details covering the
requirements.
        For prototypes the same is true except that I may not have generated
the full fab drawing yet. I will have notes in my readme and some
drawing/sketch/gerber showing the detailed dimensions and/or outline of the
slot/rectangle.

        Note: discuss with your fabricator which router bit sizes they have
available. Include and allow for the radius of the most suitable router bit
in your details. Typically I have found the following sizes common with most
fab shops, 0.094", 0.0625", and to a lesser degree 0.040", 0.031", rarely
0.020". Sometimes depending on the size of your rectangle and the available
router bits, you will end up just leaving it as a round hole anyway. There
may be no significant gain in squareness by routing with a bit that is on
the big side for the rectangular hole size.

        To make sure that it gets done as you wish, just try to imagine all
of the ways that it could be screwed up and then see if your notes/details
clearly eliminate those possibilities for a common person reading those
notes/details.

Sincerely,
Brad Velander.

Lead PCB Designer
Norsat International Inc.
Microwave Products
Tel   (604) 292-9089 (direct line)
Fax  (604) 292-9010
email: [EMAIL PROTECTED]
http://www.norsat.com


-----Original Message-----
From: Tim Fifield [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, July 31, 2002 9:26 AM
To: Protel EDA Form
Subject: [PEDA] rectangle hole?


I'm creating a connector footprint with two rectangle holes or slots for
mechanical stability. How do I create rectangle holes?

Tim Fifield


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