I do a little bit of etching and registration is important for me. The way I
do it is I take both the printouts with traces an put a Plexiglass the
thickness of the PCB in between the printout once aligned under light I put
a tape on the top of the sheet that holds both the sheets together. Now I
open it up with the tape as a hinge. Replace the plexiglass with a PCB,
laminate and etch. Some of my work that involved etching are here
http://kimsartshop.com/Bicycle.htmlhttp://kimsartshop.com/Motorcycle.htmlhttp://kimsartshop.com/CameraTrain.html ----- Original Message -----
From: "Harvey White" <madyn@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, February 23, 2008 10:22 AM
Subject: Re: [Homebrew_PCBs] Toner Transfer PCB Method
> On Sat, 23 Feb 2008 09:51:05 -0000, you wrote:
>
> One method that is recommended by pulsar (who makes TT paper).
>
> 1) take the DS board and prepare one side. Toner transfer to it.
> Registration is not a problem yet.
>
> 2) cut a piece of self adhesive shelf paper (Kmart: Martha Stewart)
> and fasten it to the unprocessed side.
>
> 3) etch the board as usual. You should get a one sided board with
> bare (and protected) copper on the other side.
>
> 4) remove the backing, do not yet tin coat the board if you do this.
>
> 5) at this point, I then drill a few well chosen holes in the board,
> and matching holes in the paper.
>
> 6) prepare the board and align the second side with the holes in the
> first.
>
> 7) run the board through the laminator again. You can use thin paper
> to protect the other side's toner
>
> 8) put a layer of contact paper (I use transparent so I can see what's
> happening) on the etched side.
>
> 9) etch the board if the registration is OK. I'd put in a pattern to
> make sure of that.
>
> 10) remove the backing, and the used toner. Tin plate as needed.
>
> 11) trim the board and drill as required.
>
> Comments:
>
> 1) this is a lot of steps
>
> 2) it's easier to align a pattern with the etched pattern on the other
> side of the board than otherwise.
>
> 3) less stress on the laminator
>
> 4) if you have a problem with both sides etching at different rates,
> this solves it.
>
> 5) you can strip the second side and reposition it if you must, since
> the first side is aligned by definition.
>
> 6) if something goes wrong on the first side, you have not wasted more
> etchant and toner transfer paper.
>
> Evaluation:
>
> seems to work so far, but I'm still getting the hang of it.
>
> Harvey
>
>
>
>>Hi,
>>
>>I'm new to this group and joined to learn other (hopefully cheaper)
>>methods of producing pcb's.
>>
>>Many thanks indeed to everyone for the infomation available on this
>>group that has enabled me to at least start producing excellent
>>single sided pcb's using the TT method and laminator
>>
>>I was using photoresist with pre-coated boards until recently but
>>this has become an expensive option these days.
>>
>>I have a laminator (Fellowes Saturn A4) and HP laserjet 1200 printer.
>>
>>The pcb I want to make measures 8.3" x 4.2" and also double sided.
>>
>>Following the instructions found on the messages for the procedure, I
>>managed to produce a good single sided toner transfer pcb of the
>>above size using pages removed from an old Toolstation catalogue and
>>8 passes through the laminator. The pcb quality was as good as the
>>photoresist method, which is very pleasing.
>>
>>The only difficulty I had was that the paper tended to crinkle during
>>the first couple of passes through the laminator rollers (earlier
>>attempts whilst locating a suitable paper for the TT method was
>>performed on much smaller boards and this problem didn't occur) The
>>answer seemed to be to place a sheet of plain copier type paper on
>>top of the TT paper for the first few passes until the TT paper stuck
>>solidly down.
>>
>>Although the laminator accepts a pcb + the thin TT paper quite
>>happily, adding yet another, further, paper layer on top of the TT
>>paper is causing the machine the stress itself. This sort of rules
>>out any attempt to perform a simultaneous action on both pcb sides at
>>the same time.
>>
>>Does anyone know a method to achieve double sided boards using
>>preprinted mag/cat paper to make double sided pcb's?
>>
>>Regards,
>>
>>Steve (GW4ZDU)
>
>
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