🚀 go-pugleaf

> 	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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