Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
The leaning tower of Piezo

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.

user:
pass:
register,


                                                               

PCB etching, poloroid style

  (+4)
(+4)
  [vote for,
against]

I don't know what kind of witchcraft would be required, but I would like a system where I can just use a pressure pen and trace the conductive trace that would be needed on this special Copper plated PCB.

Since this PCB has some special layer on top, putting pressure on it, will remove the etch resist that was layered on top of the PCB. When you are done, you roll it though a roller. There are chemicals on the bottom (similar to a poloroid) that washes the 'etch resist remover' layer, and floods the surface with copper etchers.

After a few hour, you can pull out the layer and use the PCB like normal.

mofosyne, Dec 26 2012

Direct printing http://en.wikipedia...Printed_electronics
As per [lurch]'s anno [BunsenHoneydew, Dec 29 2012]

Silver conductive ink pen. https://www.jaycar....uctive-pen/p/NS3033
* 1mm track trace width ,br. * 0.02 Ohm per mm resistivity

Solder: After heat curing only. Use low temperature soldering (less than 180oC/350oF) for not more than 5 seconds. Use low temperature soldering iron. [BunsenHoneydew, Nov 05 2016]

Using a laser cutter to etch PCBs https://mitxela.com/projects/etching_pcbs
[mitxela, Nov 05 2016]

[link]






       Where can I get a low cost or freeware PCB artwork program? Google sucks for finding programs and I don't want to torrent anymore software...
evilpenguin, Dec 26 2012
  

       I like the idea, though seems to be a hard challenge to get it working. [+]
piluso, Dec 26 2012
  

       [evilpenguin]: google eagle pcb :-)
piluso, Dec 26 2012
  

       Evidently PCB means something different to you than to me.
DrCurry, Dec 26 2012
  

       [Pilyso] thanks.
evilpenguin, Dec 26 2012
  

       DrCurry, there are "Poly-Chlorinated Biphenyls" (a group of toxic compounds frequently used in large electric-power transformers) and there are "Printed Circuit Boards" (used in most electronic gadgets), and both are frequently abbrevieated as "PCB".   

       If there are other common meanings for "PCB", I am not recalling them at this time.
Vernon, Dec 26 2012
  

       ... so nothing to do with "saddle sores" then ?
FlyingToaster, Dec 26 2012
  

       I like the idea of the Polaroid-style developer, but I don't know if you could get sufficient etchant into a small pack. You'd also have to rinse, and then remove the resist, after 'developing'.   

       Meanwhile, you can get PCB pens, with which you just draw on plain copperclad board before etching in a regular tank of ferric chloride. The ink is an etch resist. Drawing complex designs by hand, though, is tedious and errory.   

       Finally, you can also print your design on a laser printer, then use a hot iron to transfer the design to the PCB. The toner allegedly acts as a resist, though it's not very robust.
MaxwellBuchanan, Dec 26 2012
  

       What [MB] said.   

       Maplin used to do "single use" etching kits, with a thick polythene bag full of Ferric Chloride.   

       Commercial PCB manufacturers use silkscreening for the etch resist, but with the right "ink" it should be perfectly possible to modify an inkjet printer with a "straight through" paper path to literally print the mask straight onto cleaned copper. It would be slow - photo high-quality speed - but for prototyping, more than adequate.   

       You could use a conventional UV coated PCB and standard ink, if the ink were UV-opaque. But that would be a two step process, unless you mounted a UV tube inside the printer to develop the etch-resist on the fly.   

       How about a special print cartridge that replaced the nozzle with a UV laser diode and some optics?
8th of 7, Dec 26 2012
  

       etch pens are basically black sharpie pens with the sharpie branding taken off. Then they label the pen something fancy and sell them at a higher price then sharpies. [8th of 7] there's a cheaper, more fun way than inkjet printers. I used a pen plotter to make circuit boards. It was an HP 7475a. I modified the pens to be black sharpies. It had two different widths (2 different sharpies). I would tape a fresh peice of copper clad to a sheet of construction paper and run the artwork on the plotter. It worked perfectly intill I wanted 2 sided copper clad designs.   

       Haven't made any circuit boards in years and I want to get back into it.
evilpenguin, Dec 26 2012
  

       I like the plotter idea. But if you have a spare plotter, how about making a lightweight routing head for it, and carve the copper directly?   

       You'd want to modify your PCB designs so that tracks were isolated by a thin line of copper-free board, instead of removing *all* the copper between tracks, to keep down the amount of copper to be routed away.
MaxwellBuchanan, Dec 26 2012
  

       [mb] I know what you are talking about, routing out spaces between traces. There are people that do this, mostly with completely custom x y stepper tables and a stationary dremel tool mounted above it. Stationary because it doesn't go x or y, just up down. A dremel is really the smallest motor you would want to use, and its not lightweight enough to be used in a pen plotter, IMHO. Added bonus of building a custom x y table, is that it can also drill the holes required exactly on point. This is tiresome when done manually.
evilpenguin, Dec 26 2012
  

       // I used a pen plotter to make circuit boards. It was an HP 7475a. //   

       Oooh, that's a Blast from the Past ...   

       There's no reason that such a system shouldn't be able to do double sided boards as long as the indexing is precise.
8th of 7, Dec 27 2012
  

       To a limited extent you could just use a soft pencil.
nineteenthly, Dec 27 2012
  

       Why not use a heavily modified inkjet cartridge to print etchant gel directly onto the copper? Wait for the stated time, then just rinse off.
8th of 7, Dec 27 2012
  

       //Why not use a heavily modified inkjet cartridge to print etchant gel directly onto the copper? Wait for the stated time, then just rinse off// because the ferric chloride would eat away at the print head. Unless you modified it, on a microscopic level to be etch resistant, it wouldn't work.
evilpenguin, Dec 27 2012
  

       Also, pending the release of the formula for molecular acid by the Borg, a lot of etchant is needed to remove a given amount of copper - probably more than can be printed without spreading a lot.
MaxwellBuchanan, Dec 27 2012
  

       ^ arguably you only need remove enough copper to avoid capacitorization.
FlyingToaster, Dec 27 2012
  

       Instead of etching the copper off, why not print the conductive traces on? Somewhere between "dye-sublimation laser" and "3-D printer" there surely exists a conductive ink...
lurch, Dec 27 2012
  

       Now I'm going to have to try lemon juice on my pancakes.
normzone, Dec 28 2012
  

       // Instead of etching the copper off, why not print the conductive traces on? //   

       That's baked.
BunsenHoneydew, Dec 29 2012
  

       [[[Bunsen]]]
blissmiss, Dec 29 2012
  

       Hi blissmiss! I've been away (eaten by Faceborg) but I am beginning to visit here more regularly again.
BunsenHoneydew, Dec 30 2012
  

       One could try a conductive ink pen [example at link] in a plotter - not sure what it would be like to solder to afterwards. /edit/ solderable after heat treating / But it might work well in conjunction with proto board: ie, that board with a grid of holes in it, each hole surrounded by a copper ring.
BunsenHoneydew, Nov 05 2016
  

       A cheap laser engraver can just burn off the unwanted copper as a single step process.   

       Create the pcb file, stick a blank on the table, click on "go" ... oooh, sounds like hard work.   

       Plenty of vids on YouTube of PCB prototyping and small-volume production, even double sided.   

       Multilayer and PTH still require traditional processing, but it's made a huge difference to rework.
8th of 7, Nov 05 2016
  

       // A cheap laser engraver can just burn off the unwanted copper as a single step process. //   

       No it can't - I have a 40W laser and it can't even make a scratch on copper, it's just too conductive and sinks all the heat. You need kilowatts to burn through copper.   

       But I have used it to burn away spray paint on copper-clad board, and etch the copper from there, which works quite well [link].
mitxela, Nov 05 2016
  

       40W ? That's hobbyist stuff.   

       Maybe we should qualify what we regard as "cheap" ...   

       <Chief Brodie>   

       "You're going to need a bigger laser ...."   

       </Chief Brodie>
8th of 7, Nov 05 2016
  

       [mitxela], I happened to look around your website a bit, and found your Lenticular Traffic Lights idea. I then found it on here and added a link to it.
notexactly, Nov 10 2016
  
      
[annotate]
  


 

back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle