Road trip to Voltera
Several years ago our own inimitable Max published a blog “Want a Voltera Desktop PCB Printer?” that described a PCB printer that was being developed in Canada and funded through Kickstarter. The product itself was interesting enough, but that it was being done here in Canada got me really intrigued. I got myself on the mailing list, and when they recently sent a postcard advertising the finished product I showed it to my boss and he decided that we should get a demo. I contacted them and rather than them coming to us, we were invited to go to Voltera. They are only an hour away and so a road trip beckoned.
Recently I have noticed a lot of discussion about a significant uptick in tech innovation in Canada. Somehow I think this may be the unexpected upside to Blackberry’s malaise. Since the jobs at Blackberry were just not there, I reckon it inspired a lot of engineers to start their own developments. You heard this silver lining theory here first! Anyway, Blackberry is based in a town called Waterloo in Ontario. Waterloo is in fact part of a larger metropolitan arrangement consisting of 3 cities: Kitchener, Waterloo and Cambridge. An interesting aside is that Kitchener, established by German immigrants, was originally called Berlin. In 1916, for obvious reasons the authorities renamed it for the British Secretary of State for War, whose image we are all familiar with. This is a very long winded way of telling you that Voltera is in Kitchener.
Lord Kitchener in a well-known pose. (Source: Wikipedia)
The University of Waterloo is an institution of some repute in the engineering and scientific world and has one of the few co-op engineering programs in Canada. No doubt it is one of the sources of these up and coming innovators. To spur this development the university has created the “Velocity Garage” the “largest free startup incubator in the world”. Voltera is part of the endeavor and located in this building.
The space is rather like a large warehouse turned into a student union establishment- communal meeting rooms and kitchen facilities and each startup in an area with minimal partitioning. Voltera also has a workshop right next to the work area, obviously with doors that can be shut and locked. I began to understand the reason for the new work sharing paradigm I wrote about in “How Well Can You Work With Others?” Funnily enough, the Upverter package I included in the blog is also part of the Canadian innovation wave. As I looked at all these keen faces concentrating on screens and diagrams, I wondered and then dismissed the idea that I would like to work in this environment, but then I was lucky to even be allowed into the building. After all, the ink on my birth certificate is dry!
But you all would like answers to some of the questions Max (and others in the comments) posed back in 2014, so let’s see if I managed absorb the presentation correctly. There are several videos and pictures on Voltera’s web site, so if you want to see it in action head over to it. There are also several videos on YouTube.
The whole assembly, and indeed aspects of the operation, unsurprisingly reminded me of an old X-Y plotter. The mechanism consists of an X-Y controlled carriage with a Z dimension since the carriage also has an adjustable height. The bed of the device is thermally controlled. It appears to me that the mechanism and the heated bed are operationally mutually exclusive.
Figure 2: The V-One. The heating pad is flat the black horizontal rectangular area and the carriage with a conductive ink cartridge installed is visible at the top right. (Source: Voltera)
The carriage is capable of carrying different heads and this approach contributes to the versatility of the device. There is a probe, the trace deposition “head” (made up of a conductive ink cartridge and a nozzle), a solder paste deposition “head” (made up of a solder paste cartridge and nozzle) and a few more that I will get to as we proceed. The V-One is aimed at the high end of the hobbyist market and low end of the professional one- hence some compromises have been made to contain costs. There are some manual operations as part of this economy and changing these heads is one of them- surprising given the accuracy in placement they achieve.
Obviously before you start you have got to have your PCB design in Gerber format.
After clamping the blank PCB to the bed, the first step is inserting the probe in the carriage and the system goes through X-Y calibration. For trace deposition the nozzle must be held within very tight tolerances above the PCB and so the probe is then used to sense the undulations of the PCB, mapping more than a few points to record the landscape. On a blank PCB the exact location probably doesn’t really matter, but in the case of certain boards (patience, we’ll get there) there need to be fiducials and so the probe is lined up with two of these by eye.
With ink-jet spray the ink is atomized and accelerated with high voltage. On 3D printer the filament is normally heated till it flows. It appears to me that the conductive ink is extruded out of the nozzle under pressure created by the mechanism rotating a toothed gear at the top of the cartridge. Deposition of the traces is quite quick, taking several minutes for a relatively complex side. There is a flow quantity adjustment which I guess you learn to fine tune for your needs. At this point the traces are wet. You can simply wipe them off - so you need to be careful not to touch with your finger. They have to be cured and that’s the primary reason for the controlled heating pad. Apparently curing is improved with the wet traces facing down towards the heater, so the board is flipped and mounted on rails. It says a lot for the ink’s viscous properties that it can be manhandled like that and not be deformed. Curing takes about 30 minutes.