OT maybe? help with press n peel blue!!!

[mongo]

Hi everyone, been  lurking here for a while...

 Well, I want to start building my own pedals and blah
blah blah, and I bought a bunch of PnP blue sheets
(I guess most of the people here are familiar with these)

 I haven't been able to properly do the transfer to
 copper board!


 I use a HP LaserJet 5000 printer (wich is a laser
printer to my  knowledge) to put my  PC layout
from the PnP sheet to the copper board, but the
transfer with the iron and everything does not work
for me.

I clean my copperboard very carefully with the steel
wool till it's shiny and polished, and then when I
iron it to make the transfer It never happens.When I
"overheat" to see if it works that way the PnP sheet
kind of melts, and if I do it at the reccomended
temperature the transfer does not take place.

 Am I doing something wrong? PnP blue is supposed to
transfer with a blue layer but when I get to  transfer
something (after 40 minutes of heating) it's the black
Pc layout without the blue layer.

 I contacted techniks with no success whatsoever so,
 if someone could explain me what am I doing wrong
 I will be very very thankful.

Thanks in advance,

Andy

[Paul Perry (Frostwave)]

I hope you printed on the right side? (I know.. but, it is possible!)

[mongo]

the right side is the DULL one right??? ;-)

[punkaled]

 Am I doing something wrong? PnP blue is supposed to
transfer with a blue layer but when I get to  transfer
something (after 40 minutes of heating) it's the black
Pc layout without the blue layer.

Well, it only takes a few minutes here (not 40)

But i'm not sure what you mean by "the black PC layout without the blue layer". That sounds like its working fine to me.
You wont get a blue print on the copper board, you should end up with a copper board with all the circuit traces marked on it in black.
PnP is not a magic tool or anything, all it does is transfer the printed image from the paper onto the copper board, Then when you etch it the etchant "eats" all the copper it sees, leaving only the copper under the black print, you then polish the print off and your left with your pcb.
So you see, all you should see on the board after ironing is the mirror image (in black) of whatever you printed.

If i misunderstood the question and your actually not getting anything on the copper board after ironing, then maybe you printed the wrong side of the paper, or didnt have a hot enough iron?
i use a laserjet printer too, so that isnt the problem.

[Paul Perry (Frostwave)]

You wont get a blue print on the copper board, .

Actually, you do! That is the whole point of the blue!
And, it's been a while..but I'm sure it is the rough side.
Here are over 3,000 opinions:
http://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=pnp+blue+pcb&btnG=Search

[sir_modulus]

40 minutes!!!!!!!!!!!!!!!!! no wonder, thats WAAAAY to much time. The sheet will easily melt with that much time/heat.

[mongo]

well I've tried different temperatures hot, less hot, very hot... with no success.From  the little "how to" I recieved with my PnP sheets and the net, I understand that I should print my CB on the DULL side right? not the  "shiny"  side...

I know that 40 minutes is a lot of time, but I just kept ironing to see if SOMETHING happened! ;-D



 So,I don't know what's going on.This thing seemed very reliable but I'm sure I am doing something wrong!

A+

[mikeb]

Depending on the make-up of the toner (the powder that is heat-fused to the pnp blue inside the laser printer) you may need to experiment with with different iron temperatures. I used to use my old workplace's HP 4M+, but now use a Brother HL1440 I have at home - this change resulted in me having to use a higher temperature on the iron.

This is what works for me:
- cut and file board so that there are *no* raised edges (which could prevent the iron from making contact with the pnp blue at same places)
- clean copper board with steel wool,making sure you don't touch the board (fingers->oil)
- preheat board with iron (30 or so seconds at the 'magic' temperature
- drop / place pnp blue on board (with a preheated board you only get one chance at this, so be careful!    )
- apply iron, and don't move it until the pnp blue is 'stuck' to the board (the toner is melting), maybe a few seconds?
- move the iron firmly and even around the pnp blue until all traces appear 'darker' (the toner has transferred from the pnp blue to the board). This is the most tricky part, and usually involves finding a balance between 'overtransferring' one part of the PCB pattern (toner gets squashed sideways bridging tracks or making a real mess) and 'undertransferring' another part (toner doesn't make the jump from pnp blue to the board, or is flaky etc)
- remove the iron. Wait a few minutes for the board to cool enough to touch, then run some cold water over it. At this stage you can gently start peeling off the pnp blue from one corner. Tip - if the PCB pattern doesn't transfer in it's entirety, keep the pnp blue sheet and place it over a light surface - this will reveal where some touching up is necessary on the board using a permanent marker
- etch, and enjoy the feeling of a job well done

Using the above method (and in the early days I did have some failures) I've made hundreds of PCBs. Now the only *really* painful part is drilling them!

Best of luck!

Mike

[Samuel]

Are you letting the board cool before lifting off the sheet? I usually run the board under cold water for a minute after I'm confident the transfer has been made.

[soundcollage]

Isn't the laserjet an inkjet (non-toner based ) printer?

[MartyB]

Yep.  I think that's the problem you're having.  Laserjet is ink, not toner.  Toner copiers basically melt powdered black plastic onto paper.  The PnP blue takes advantage of this.   The image is melted onto the blue dull side, then re-melted in mirror image onto the copper clad.  If you use an old-style toner transfer copier (black powder mess is the telltale clue) then PnP becomes as easy as you expected it to be.  I've been doing it for a couple of years now without problems.  If you'd like you could mail me your PnP and I could print the circuit out with my copier at work. PM me if you want.
MartyB

[mikeb]

Whoa - that's not right. 'Laserjet' is just HP's model name that they've used for years. Doing a quick web search results in:
http://www.rechargermag.com/article.asp?id=199902070
... any printer with a 'fuser' is a laser / toner based printer that *will* work with pnp blue ... not to mention no inkjet that I know of can do 16ppm....

Mike

[MartyB]

MikeB You're probably right.  So why doesn't the laserjet work as well?  

http://www.rechargermag.com/article.asp?id=200312192

[Mark Hammer]

The principles behind PnP....

The "blue" part is an emulsion that sticks to the plastic acetate sheet.

Toner sticks to the blue emulsion.....BUT....toner sticks *better* to the copper than the blue emulsion sticks to the acetate.

Think of it this way.  It is a tug of war between the acetate and the copper.  Having a clean copper surface and fusing the toner with the copper is like giving one side in a tug of war big Doc Maartens with cleats.

When you let the PnP cool after ironing it, the toner refuses to let go of the copper, but the blue emulsion (which is stuck to *some* of the toner) lets go of the acetate.  Voila!  Un petit miracle!

One of the nice things about PnP is that the shiny side really IS shiny.  As the toner sticks to the copper, you will start to see a little "bas relief" of the layout show up.  When the sheet is heated properly, the area of the sheet *around* the toner will soften and form around the traces to produce that bas relief.  When you can see the entire pattern on the shiny side, then its done.  Wait until it is TRULY cooled off before you pull or else the bond between toner and copper won't be stronger than the bond between emulsion and plastic.  One way of cooling it off quickly is to place the copper board on a window to let the glass absorb the heat.

[Samuel]

laserjet = laser printer. I think that's how they got the name.

[mongo]

My  guess (efter reading your posts) is that my problem is the printer. Just to make sure I'll try another laser printer.I would try  on a copier, but the copy guy in Paris are more than reluctant to put my PnP sheet on their precious copiers...

 A+

[Mark Hammer]

Few photocopy employees have seen PnP before so I don't blame them one bit for being anxious about possibly ruining a machine costing several thousand dollars.  What they need to know is that it is *identical* to photocopyable acetate transparencies.  It just happens to have a blue opaque emulsion on it instead of a dull transparent one.  PnP IS a photocopyable transparency sheet with a coating that toner sticks to (just like "real" transparency sheets).  If the copier cannot handle transparencies, fine, but if it can do transparencies it can do this.  The only difference is that its blue not clear.

Here's a service that many of us can provide to some of our less fortunate brethren.  Most people who have worked with PnP have probably made multiple copies of a layout just as insurance in case you messed up the first time by poor ironing technique or not waiting until it is fully cooled.  The extra copy is just sitting around, perhaps to be shared with a friend, or just as a backup.  Those people like mongo who need to be able to demonstrate to a photocopy clerk that PnP will *definitiely* NOT turn to melted plastic mush inside the copier need proof of that to convince others.  Why not send them one of your spare layouts so that they can show the clerk what the toner looks like when the sheet (safely) comes out the other side?  It will cost you the price of a postage stamp, and I'm sure the recipîent will gladly repay your kindness by sending you one *their* spare layouts once they manage to persuade the photocopy clerk.

[mongo]

wich printers work the best for this kind of job?... this HP that I use seem not like a good option, I say this looking at the poor results I get from it...

 I might consider buying a REAL laser printer if this  what is keeping me from  getting a good result...

but then again, wich temperature works the best? I can say I've tried almost everything: hot, not too hot, very very hot...

 and once again, do I print te layout on the DULL side right??

 Thanx again,

 the PnP challenged mongo in Paris.

[mikeb]

Well, I've had success using a bunch of different printers in the HP laserjet range - maybe it *is* the toner? I've only ever used 'real' HP toner cartridges; it doesn't make sense in the bizs I've worked for to try and save 30 minutes of the lowest salary of a worker there for non-authentic toner.

Yes, you print on the dull side - however, I've screwed up sometimes and find that printing on the shiny side works almost as well.

I guess I've been luckier than some with PNP blue.

Mike

[Paul Perry (Frostwave)]

In general, the OLDER a laser printer is, the better. Because, older ones put a thicker layer of toner on the paper.
And modern ones may even have "miser mode" to deliberately put as little toner as possible on.
If you could find one of those BIG old early HPs, you might be lucky. But note, you will have to find a cartridge as well, because it is expensive & difficult sometimes to get cartridges for old machines.
Tehre is also the photocopy route, but watch out for distortion (especially at the edges of the sheet).