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From: nagle@netcom.com (John Nagle)
Subject: Re: Double Sided Boards
Message-ID: <nagleD3pwzI.833@netcom.com>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
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Date: Thu, 9 Feb 1995 05:38:06 GMT
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Xref: glinda.oz.cs.cmu.edu comp.robotics:17766 sci.electronics:118799

Christopher Cifra (cgc3@po.cwru.edu) wrote:
> Hi,
>    I'm working on a project and am thinking about
> constructing an etched double sided board, but I can't think of
> how traces from one side would be electrically connected to traces
> on the other side.  My router connects top side traces to bottom side
> traces through IC pin holes, but it would be impossible to solder the
> pins to both sides of the board.  So how is this normally done?

      A practical answer is that it's done by having a board fab house
do it.  The going rate for a small board is $50-200 for the first one;
the second one costs only a few dollars.  
Look at ads in "Circuit Cellar INK", "Midnight Engineering", or "Nuts
and Volts" for companies that cater to hobbyists.  A few years ago,
the cheap board shops for hobbyists only did single-sided boards, but
now many do double-sided boards as well.  

      The usual procedure is that you send the board house a file in
some format (there are a number of formats in the industry; ask your board
house which they accept), along with a check, and you get boards back.
The file comes from a PC design program, of which there are many.
Some are even free, including limited versions of high-end board design
products.

					John Nagle
