here is the methodology that I have applied to such a problem
previously with good results (no fab shop ever got it wrong).
        On your board the copper pattern is no problem because you can have
square or rectangular pads or fills. Specify the hole in your pad to be very
small (i.e. 1 mil), this will highlight it to the attention of incoming CAM
inspection because they know they cannot drill it. In your text drill file
specify the drill size for that tool by manually overwriting the automatic
drill table size and indicate it is rectangular. Now this is where I would
say that a fab drawing is required. On the fab drawing make a special note
regarding your rectangular hole and it's tool number in the drill file. Draw
a detail drawing of the rectangular hole using the drill center as the
center of the feature. Be sure to indicate on your detail the orientation of
the rectangular hole.
        If you have more then one orientation or size of the rectangular
hole(s) use another small drill size (i.e. 2 mil) and another detail drawing
to indicate the orientation of that rectangular hole. If you have lots of
these rectangular holes you might have to seriously consider how to document
them all because for more then a few occurrences my method can become rather

        You do have another consideration to work out as well. That is what
radius can you allow in the corners of your rectangular hole? This would be
best worked out in conjunction with your Fab shop. Your min. width is 50 mil
but this shape must be routed, a typical shop might have a 32mil diameter
router as their smallest size 
router bit and therefore your corners will have a 16mil radius. Just
something to consider when sizing your rectangular hole.


Brad Velander
Lead PCB Design
Norsat International Inc.
#100 - 4401 Still Creek Dr.,
Burnaby, B.C., Canada.
voice: (604) 292-9089 (direct line)
fax:    (604) 292-9010

-----Original Message-----
From: TSListServer [mailto:[EMAIL PROTECTED]]On
Behalf Of Brad Marshall
Sent: Monday, February 12, 2001 8:27 AM
To: Multiple recipients of list proteledausers
Subject: [PROTEL EDA USERS]: Rectangle holes

I have a person here that wants a 50mil X 250mil rectangle plated
through hole.  I am having trouble figuring out the best way to do this
with Protel so that the board house will know what I want.  Any
suggestion/comments are appreciated.
Brad Marshall

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