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- From: johnh@macadam.mpce.mq.edu.au (John Haddy)
- Subject: Re: PC board manufacture: my technique
- Message-ID: <1992Nov6.005411.26186@mailhost.ocs.mq.edu.au>
- Sender: johnh@macadam (John Haddy)
- Nntp-Posting-Host: macadam.mpce.mq.edu.au
- Organization: Macquarie University, Sydney
- References: <Bx5L9B.EJ8@wang.com>
- Date: Fri, 6 Nov 1992 00:54:11 GMT
- Lines: 34
-
-
- > I have made a number of small boards up to 2 by 4.5 inches
- > using this process and some with very fine traces and spacings.
- > I complete the etching of one side before I apply the toner
- > to the other side. I don't know it this process will scale up to
- > larger sizes well. It seems to me that the steam step is
- > particularly important. Before I did this traces would pull off at
- > the edges of the board as the board cooled.
-
-
- This process is unlikely to scale much _because_ of the steam step. The
- paper will swell and hence dimensional accuracy will not be maintained.
- Our laser printers print accurately onto the paper _before_ it hits the
- fuser section. Because of the inherent sizing distortion caused by the
- heat cycle in the printer, we need to let the paper (or mylar, more
- usually) "rest" for an hour or two before proceeding to the next step.
-
- I've noticed about a 1-2% error in sizing when the paper first comes out
- of the printer (this is serious for big components, such as edge
- connectors or DIN41612 plugs and sockets). The paper restores its
- dimensions as it rests.
-
- JohnH
-
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-
- | _ |_ _ |_| _ _| _| Electronics Department
- |_| (_) | | | | | | (_| (_| (_| \/ School of MPCE
- ---------------------------------/- Macquarie University
- Sydney, AUSTRALIA 2109
-
- Email: johnh@mpce.mq.edu.au, Ph: +61 2 805 8959, Fax: +61 2 805 8983
-
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