Quick and easy DIY PIC development board


A few months back, [Phil] was looking to get into PIC development, but he couldn’t seem to find a simple development board for the PIC16F883 microcontroller he wanted to use. Since no retail offering had exactly what he was looking for, he decided to put together a dev board of his own.

He spent a couple hours in Eagle, putting together a simple board layout. [Phil] then busted out the iron and copper clad, making his dev board a reality using the tried and true toner transfer method.

He says that the board itself is quite simple, consisting of little more than the PIC, an LM1117 linear voltage regulator, and all the pin headers you could possibly need. While very basic and not necessarily a hack, we do like seeing people make their own tools when the market doesn’t provide what they want.

If you have been looking around for a simple PIC development solution, be sure to swing by [Phil’s] site – all of the schematics and layout files are free for the taking.

Test your etching chops with PCB map making


[Martin] had been using standard perf board for most of his electronics projects, but as he was starting to utilize more surface mount ICs, he quickly realized that it was time to start making his own PCBs. Having never etched any PCBs using the toner transfer method, he figured it was as good a time as any to give it a try.

Rather than make a board for a particular project, he decided to try his hand at etching a very detailed map of the Paris Metro as a test pattern instead. He grabbed a large image of the subway map, then printed it out on the back of a supermarket flyer. He attached it to his PCB and ran it through a lamination machine to transfer the toner. He figured that the laminator would be easier than an iron to use, and was right for the most part. The only issue he had was that the laminator did not generate enough heat, so he supplemented the its heat output with a hair dryer.

When everything was said and done, he had a pretty good looking PCB on his hands. Most of the Metro tracks and text came out just fine, though he admits there is a bit of room for improvement. It looks nice when mounted in a frame, though we would love to see a functional circuit made out of a PCB map like that. Heck, we’d even settle for a double-sided PCB with a street-level map on one side an the Metro on the other!

Tuesday Two-Fer: Battery Cases and ABS Lettering

These are both interesting, unrelated, and can’t quite stand on their own so we threw them into one post.

On the left you see the product of using toner transfer on ABS plastic. [Bogdan] tried this out as a way to make front panels for his enclosures. It really shouldn’t work very well because ABS has a lower melting point than toner does. But it seems that it takes a while for the ABS to heat up. If you’re quick, ironing for about 10 seconds, you can get the toner to stick to the plastic and then soak the paper off, leaving your printed design looking nice and clean.

To the right you see a printed battery case. [Nikolaus Gradwohl] ran across the same problem we’ve face many times: how to attach batteries to your projects? We’ve duct-taped them together, used the blister packs they’re sold in, Dremeled them out of thrift-store toys and just about every other thing you can imagine. He decided to make them easy to manufacture with a 3D-printer. This is accomplished with an OpenSCAD file he wrote. Plug in the size and number of batteries and a printable package will be automatically generated.

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.

Print toner directly to a PCB

We use the toner transfer method to fabricate printed circuit boards. The most difficult part of this is printing, ironing, and removing the paper from the toner that is used as an etchant resist material. [Mark Lerman] is developing a method to apply toner directly to the copper clad using a laser printer. Each of the photos in his gallery have comments that take us through his process. A laser printer has been modified to negatively charge the copper plate, thereby attracting the positively charged toner to it. Once the toner has been applied, the board is baked in an oven, then run through a laminator. This process can yield 2 mil traces and it looks like the potential for incredibly clean boards is just around the corner. The question is, will this be easier and take less time than using photo resist?

We’ve contacted [Mark] in hopes of getting more details. If you can’t wait for a follow-up, take a look at this thread concerning his work.

[Thanks Komradbob]