> -----Original Message-----
> From: piclist-bounces@mit.edu 
> [mailto:piclist-bounces@mit.edu] On Behalf Of Olin Lathrop
> Sent: Wednesday, November 23, 2005 6:00 AM
> To: Microcontroller discussion list - Public.
> Subject: Re: [EE] Notched PCBs
> 
> David Van Horn wrote:
> > The problem that I'm seeing, is that the router shoves the kerf over
> > into the drill hole.
> 
> I haven't seen that.  In fact my sliced pads were actually at 
> the ends of
> channels routed in from the edge, not at the edge directly.  
> I made the pad
> hole just a little wider than the channel, and made sure the 
> router stopped
> just short of the center of the pad.  That way I got maybe a 
> 2/3 ring of pad
> and plated hole.  We are doing this because it will be a lot easier to
> attach an assembly with pre-formed leads to the board by sliding it in
> sideways then soldering it on.  So far we've only had a few prototypes
> built, but none of the boards had any krud in the holes when 
> they came back

That's neat.  I like it very much.  You are limited to fairly large
holes though, right?  .062" or so?  Will they do smaller diameter
milling?

One slight alternative I might suggest is to make the pad with no drill
at all, rather define the 'drill' as a plated slot that extends from the
center of the pad to beyond the board edge.  The board milling then just
cuts straight across the slot without deviating into the slot.  That way
the entire slot will be plated and there's no worry of edge milling
tolerance damaging the plaiting in the 'hole' area.  That would however,
leave plated material at the board edge (which may/may not be an issue,
depending on application), but you could eliminate that by deviating the
board edge mill slightly into the slot, beveling the corners.  

Gary Crowell, CID+
Micron Technology

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist