[sdiy] making PCB's with PNP blue

[Tom Wiltshire]

The two tips I'd add to what others have said;

1) Run the PNP through the laser printer first without printing anything. This pre-shrinks it and avoids it changing size when you do print it.

2) Don't put it in a bath of ferric chloride. Instead, put on some washing-up gloves and sponge it with ferric chloride. The sponging wipes the reaction products off the board and exposes clean copper which makes the process much quicker. Plus you can see what's going on and only need to sponge the bits that need it.

I've managed some pretty fine traces using this technique, but I wouldn't use it for SMD stuff, although I know some people do. These days I find that the extra density and extra-fine traces I can get using commercially produced boards are too much of a draw for me to want to do my own.

Tom


On 2 Nov 2011, at 00:51, aankrom wrote:

> OK, I'm sure we've all talked about making PC boards on this list before, but when I googled how to etch PB boards, I got a lot of hits and none seemed to really tell me what I wanted to know.
> 
> I plan on etching the boards in a Pyrex cassarole pan heated with a heat lamp connected to a Variac. How hot should the bath be? I have a cool electric thermomter, but it needs a thermocouple. I s'pose a candy thermometer will work...
> 
> I have solid FeCl3 to mix. It says 1/4 lb makes a pint which doesn't seem like a lot. I'm expecting the dissolution of the FeCl3 to be exothermic so I won't mix it in a plastic container.
> 
> When "ironing" on the PnP with circuit pattern do you really put the iron right on the PnP or should you put a piece of paper in between? How long is long enough?
> 
> Does anyone know of a definitive link eprhaps?
> 
> Anthony
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy