Printed Circuits

[Charles Lindsey]

I read somewhere that it was possible to make printed circuits using a
laser printer (one assumes, of course, that the paper track in the
particular printer was straight enough to take the extremely stiff board).

Would not the conductive layer of copper on top of the board prevent the
normal electrostatic transfer of the black stuff? I accept that, if
transferred, normal toner should be an effective etch resist.

Alternatively, is it possible to use an inkjet printer for the purpose
(again assuming the paper track was straight enough, which might be easier
that with a laser printer). But does anyone know whether normal black
inkjet dye would be an effective resist?

 

[Fred McKenzie]

I read somewhere that it was possible to make printed circuits using a
laser printer (one assumes, of course, that the paper track in the
particular printer was straight enough to take the extremely stiff board).

Charles-

I do not recall the details from many years ago, but I don't think the
circuit board passes through the printer. I believe a Xerox copy or a
Laser print of the artwork is used.

I don't recall whether it was a photographic approach using sensitized
materials, or something like ironing T-Shirt artwork onto a copper board.

If no one here can provide details, perhaps some other group would have
the resident expertise. Maybe sci.electronics.equipment or
rec.radio.amateur.homebrew?

Fred

 

[Bob Eager]

I read somewhere that it was possible to make printed circuits using a
laser printer (one assumes, of course, that the paper track in the
particular printer was straight enough to take the extremely stiff
board).

Would not the conductive layer of copper on top of the board prevent the
normal electrostatic transfer of the black stuff? I accept that, if
transferred, normal toner should be an effective etch resist.

Charles

I have a book that discusses this. The 'home' method is that you print
the resist pattern on a piece of paper. Then you clamp it to the PCB
blank, and use a hot iron and much pressure to remelt the toner and
transfer it to the board. Results are apparently mixed, but it can be
done. Not that you'll get much 'definition' with it... But clearly this
method won't work with an inkjet.

The second method is to print (inkjet or laser) onto transparency film.
Then use a photoresist blank PCB and develop it. Rapid Electronics and
CPC sell suitable film.

The third method is to use "press-n-peel" film, which is a sophisticated
version of the first method! Rapid and CPC sell this too.

Hope this helps.

 

[Bob Eager]

And Maplin at £16 for 5 sheets of Press & Peel. I've just tried using
this and it wasn't a brilliant success. Three attempts and I couldn't
get all the tracks to transfer from the film to the PCB. (Could be
something I'm doing wrong so don't let me put you off trying). The small
amount of missing bits could easily be filled in with a fine point
sharpie. A functional but not pretty result.

I have this pathological aversion to Maplin! Probably cheaper to go to
Rapid and pay the small order charge! (no, I haven't checked...)

I don't think it's that satisfactory either, but Charles was asking about
the mechanism. In the long run, I'd probably use a package like 'pcb', or
the limited free Eagle app, and get someone to make the board.

 

[Bob Eager]

Back in the old days when they sold components they weren't so bad. Now
it's all toys.
I was trying to make a small PCB to start a friends son off on a school
project.
The PCB was still available but at £30 I'd rather bumble through with
Press & Peel.

I agree. I was one of their very early customers in the mid 1960s!

 

[Jerry1111]

I read somewhere that it was possible to make printed circuits using a
laser printer (one assumes, of course, that the paper track in the
particular printer was straight enough to take the extremely stiff board).

Print tracks on a 'glossy' paper (i.e. from a cheap, glossy magazine).
Clean the board (I'm using 1000-1200 wet sandpaper). Use a non-steam
iron to warm the board up. Once hot (you have to find best temperature -
if it's too hot then the toner will melt completely) press the toner to
copper (I'm using an old sock ;-) ).
Some people are having good results by passing the board together with
printed paper through a modified cheap laminator (you have to increase
the temperature to 160-180C).
I was having very good results with old Laser 4MP. Looks like not all
the toners are good for this transfer. I was able to pass 2 tracks
between SO8 pads - not a bad result!