PCB making question

[fiend138]

            Hey is it possible to run the iron too hot when applying the pnp blue to the copper board? The pnp sticks from the residual heat, but it peels after laying the iron on for 30 seconds like tonepad suggests. So when i go to apply firm pressure the pnp moves,

thanx
max

[Xlrator]

I always keep my iron on it's hottest setting. I also use a small piece of tape to hold the PNP in place. I always cut it to the exact size of the board so I could see if I'm not aligned properly. I've never had one slide. I sandwich my board between a smooth aluminum sheet (hammond encosure works, too) and a couple sheets of paper. I apply heat longer than 30 seconds, checking the corner once in a while.

Also make sure your copper is really clean before you apply the PNP!! Skuff it up with some light steel wool or brillo pads first.

Great stuff! Good luck!

[Mark Hammer]

A little hunk of smooth flat MDF board is good for ironing on.  Part of the secret is to wait until the copper board is truly cooled down before peeling the PnP off.  I don't mean just cool enough so that you don't burn yourself.  I mean cool enough so that the toner plus emulsion that has fused with the copper is hard and STUCK ON.  Yanking the PnP or photo paper (whichever you choose) off too soon may result in toner changing its mind about where it wants to live and "moving back home" to the backing it came on.

Given that it is winter in many places, I find a very useful means of cooling a just-ironed board off is to press it up against the glass of a window.  That dissipates the heat very nicely in thorough way, and fast enough that your desire to peel the PnP back and see the successful transfer can be appeased. 

[newperson]

I use med to high heat and iron the board on a phone book. The phone book keeps the board from moving and keeps the heat on the copper (it seems).  I also use a clean piece of white copy/printer paper to go between the blue and the iron.  I have never had it to slide on me no matter how hard I press down.  I have tried using a piece of paper that had something printed on it and where the print was, the traces did not stick to the copper.  So from now on I use a new sheet.

I agree with allowing it to fully cool is important. 

[fiend138]

Hi thanx for the responses. Can an iron give off humidity even if there is no water but the steam button is on? The Pnp blue bends upward at the edges and looks melted.

Thanks
Max

[nelson]

Hi thanx for the responses. Can an iron give off humidity even if there is no water but the steam button is on? The Pnp blue bends upward at the edges and looks melted.

Thanks
Max

sounds to me as if your iron is just simply too hot, turn the thermostat down a bit.

[formerMember1]

yeah, the only problem i ever had with ironing, is ironing too hot and too long, i find medium heat on steam setting is best,...also alternate between ironing and letting it sit on there for 30 seconds,...

i run it under cold tap water, before peeling the pnp back,...

if the edges are crinkled i guess you have it too hot like nelson said 

[fiend138]

Hey thanks everyone for the help and advice. I found my best method is to go over each line very carefully and to tape the PNP down. I have just one more question. I etched a LBP and the rangeblaster from fuzz central. The LBP turned out fine, but some of the traces on the rangeblaster got eaten by the etchant is there any way to salvage this board?

Thanks
Max

[formerMember1]

it depends on how much the traces got eaten.  If only hairline cracks you could apply flux to the traces(tiny tiny amount), then tin with solder,..that should make everything right for ya,..if it is worse, you could use bare copper wire or a cut resistor lead and solder it along the trace.

THAt resistor lead "trick" should work on the rangeblaster since the traces are that intricate, and they are mostly straight,...

[no one ever]

conductive pens.

[Xlrator]

To expand on this topic,

What is the green coating that is sprayed over the traces. I don't tin all of my copper traces and some are pretty tight to do with an iron. So some of my older boards have varnished/turned colors. Does Mouser sell some kind of spray-can for this? I don't know the name.