Etching panel faces on the cheap

[James] came up with a way to make small numbers of high-contrast instrument panels cheaply, and without too much labor. We’ll make with the bad news right away; you’re going to need a laser cutter to use this method. Traditionally, panels that look like the one above are etched onto special composite that has one color at the surface and a contrasting color beneath. [James] started with plain old acrylic, etched his labels, then filled the voids with black wax crayon. Just scribble all over the etched face to rub wax into the grooves, go through a couple of cleaning steps using white spirit, then bake the panel to even out and harden the wax layer. He’s got several examples of his work, including medallions that are used to label LED indicators.

Printable wax as PCB etch resist

What if there were only two steps for making your own printed circuit board; print, etch? That’s what [Jeff Gough] has been working on and he presented the process in his talk at 27C3. In the first portion of the video after the break [Jeff] talks about various industrial PCB manufacturing processes in a depth you may not have heard before. We found it to be interesting but at about thirty minutes into the clip he begins the presentation of his modified printer. It’s an inkjet that can print wax onto copper clad board. The wax acts as a resist for chemical etchants, and provides very high resolution. He’s using a heavily modified print head, which brings to mind that diy piezo inkjet head which also has wax printing in its future plans. This certainly seems promising and if the process can be simplified it might do away with the toner transfer method.

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High Voltage Etch a Sketch

What do you get when you mix a simple X/Y plotter, a Flyback transformer, and an unhealthy disregard for safety? Possibly the worlds most dangerous jumbo Etch a Sketch! [Kalboon] started off by making an imprecise X/Y movement device, similar to a CNC machine setup, but with less emphasis on precision. This rig is powered by some commonly salvagable materials, including an old scanner, a remote control car, and some hobby servos. We like this approach because most of these materials could be scrounged from a parts bin, surplus sale, or craigslist for little to no actual cost. The flyback transformer comes from an old TV or monitor, though if you have common sense safety concerns, we would recommend just mounting a dry erase marker and a dry erase board to substitute out the high voltage bits. For people wanting a low cost introduction project to making a CNC or Makerbot style build, this isn’t a bad place to start.

Direct to PCB inkjet printing

[Rhys Goodwin] has been working on a system to print resist onto copper clad using an inkjet printer. This is a toner transfer alternative as it still uses toner, just not quite as you’d expect. The first step is to modify an inkjet printer, separating the carriage from the feed rollers in order to increase the clearance for the substrate. Instead of printing with etch resistant ink, as we’ve seen before, [Rhys] prints with black ink and then covers the board (ink still wet) in laser toner. Once there’s good adhesion he blows off the excess and bakes the board in a sandwich press, with spacers to keep the iron from touching the surface of the copper clad. This cooks the resist into a hard plastic layer and the board is ready for the acid. Watch him walk you through the process after the break.

[Rhys] uses the same method for silk screen, printing in red and baking the ink onto the substrate without added toner. This produces a nice looking board but it’s still quite a bit of work. It certainly sheds more light on the process than that laser-printer method from back in May. We hope you’ve been inspired by this and come up with the next innovation that makes this process easier.

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Negative laser etching

[James] has been refining a method of negatively etching metal with a laser. He had been using a product called Thermark which is designed for this process, but it’s quite expensive. He found that paint designed for wood stoves works just as well. To prepare the surface he bead blasted it and then cleaned of the residue and finger prints off with acetone. The board was preheated in an oven before covering it with the spray paint. He ran the laser at 98/100 power and 90/400 speed at a step size of 0.1mm to achieve the results above. This should immediately make you think about making circuit boards. We’d love to ditch the toner transfer and we’re always looking for one more reason to get a laser cutter.

Make your own toner transfer paper

Who would have thought that some corn starch could be made into toner transfer paper? We’re not sure of the advantages (perhaps its cheaper?), but if you have a lot of time or just love to get sticky [Matthew Sager] shows the proper method for making the paper, printing, and then etching a PCB.

If you’re just getting started making PCBs, we recommend you check out these DIY circuit etching videos to get a better grasp on the printing and etching steps.

Toner transfer explained step-by-step

[Tanjent] send us a link to his tutorial on the toner transfer process for fabricating circuit boards. We’ve seen a lot of these in the past, but we liked how his is straight to the point while also sharing several tips and options along the way. Notably, he ”tints” the copper clad before trying to adhere the toner to it by swabbing on a bit of etchant. His reasoning for this is that the toner has more trouble sticking to the shiny copper. Just a bit of etchant will pit the surface and let the toner stick better.

He’s still using paper as a medium and not printing toner powder directly to the copper clad. His paper of choice is HP Brochure Paper while we use glossy pages from the union newspaper. But like us, he does use copper chloride as an etchant, which you can learn to make yourself. We’re still looking for a definitive solution for disposing of this chemical. We’ve been using the same batch for years and recently it’s turned cloudy with impurities. If you’ve got disposal tips let’s hear them in the comments section.