Circuit Board printing at home
This week I want to talk about a great project another Waterloo
sufferer grad has created: A all-in-one circuit board printer, paste dispenser and re-flow oven. You can do circuit board printing at home!
Whenever you want to create an electronics project, you usually have to have some amount of circuit design. (Unless you are playing with
Lego Arduino) This usually cools the fire a bit on your project, as you have one of two options for PCB manufacture:
- Make it yourself
- Pay a circuit board house to make it
Traditionally, I had always done #1, with ferric chloride, a laser printer, and a lot of patience. I definitely recommend making circuit boards yourself as a student, because it is the fastest, cheapest, and best way to learn about the PCB process. However, as I have gotten relatively busier (and relatively less-poor), I had switched to getting my circuit boards made for me. (Check here for links) The upside is less time spent huffing questionably safe chemicals, the downside is a trade-off of time for money. The faster you want your board, the more you are paying for it.
- Cheap ++
- Fast +
- Labor Intensive +++
- 2 layer board possible, hard to do
- Cheap or Fast, not both
- High Precision
- Multilayer boards
- Easy +++
- Fast ++
- Easy ++
- “2 layer board” possible
* Note that Cheap in the Voltera case is only if you are making a significant number of boards. At $1.4k, the cost of the machine pays for itself in as little as 10 prototype boards made with an overnight service like APC.
Here is the killer app of the idea though: The swapable head. I give huge kudos to the Voltera team for developing an incredibly complex paste that can be printed, but is then also temperature stable enough for soldering at reasonable temperatures. Being able to press the start button and walk away is a huge boost to productivity. When I had to etch boards and solder paste stencils by hand, it was cheap, but required hours and multiple re-tries to get it right. A slight downside is the need to swap heads twice each print, once for traces, once for isolation print (to get 2 layers), and again for connecting traces.
After printing, the system can dispense solder paste to each pad. When I started making circuits, I hated solder paste and reflow, as carefully placing the components one by one seemed slow and more error prone than simply soldering each one. However, the magic of reflow is that each part will float a little, and correct its own position. This allows you to be less careful with positioning than you would be with hand soldering.
About the only downside I can call out about the printer is the lack of drilling ability. With the swapable head setup, it should be fairly easy to design in a small rotary bit attachment to automatically drill holes. This would allow vias and through-hole components to be used. Recently, Voltera posted an update with a step in the right direction for through hole components. The printer will leave a small non-inked circle in the middle of the through hole pad, to prevent the drill head from drifting while drilling.
With the right material provided by Voltera, I am sure that the next version (or maybe even software upgrade to this version) could allow for printing on both sides, drilling a hole through, and filling the hole with conductive paint. This would allow the setup to truly start to compete with traditional 2 layer boards. I suspect the Voltera team wisely chose not to overreach for the Kickstarter campaign, and may sell the drill attachment as an add-on later.
It remains to be seen how long printed boards survive in harsh environments. Things like vibration, corrosion, and even dust can destroy home printed boards. I would love to see if the printed material is flexible enough to use on flexible plastic. This would allow a whole range of great applications, from smart clothing to innovative sensors.
It is interesting to see a lot of the same movements that had been made in the 3D printer space now being applied to the electronics space. Makerbot and similar companies have proven that people are willing to spend a few thousand on making small 3D models. Will they be willing to do the same for electronics? A clever move for Voltera now would be to open a “Thingiverse” type setup for electronic circuits. Perhaps, let people upload a design and a BOM. Creating a marketplace where people can sell both designs and entire kits would be a great way for Voltera to generate ongoing revenue. The other question is whether or not Voltera will be able to hang on to their secret formula for conductive ink. If aftermarket inks start proliferating, it could bite into future sales.
You can check out the project here: Voltera
Their Kickstarter is running for another 6 days, so go now!
Thanks for the shout-out for the ruler 🙂