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3D-Printed Circuit Boards, For Solder-Free Printable Electronics
An anonymous reader writes "Check out the latest success of the OpenSCAD 3d-printed electronics library. To use it, you just need a 3D printer and some conductive thread. OpenSCAD generates a component holder, and conductive thread wraps it all together — no solder, no etching chemicals, no sending out for anything. The instructable takes you through all the steps from schematic to circuit, and includes a more useful example: the fully printed LED flashlight."
It would have been nice to see it without having a full-screen pop-up ad telling me to subscribe to instructables whenever I click on a link.
I might, and I'll be able to pretty soon, from the looks of things.
But I'll pass until it can print BGA's. Seriously, for the complexity it can do now a breadboard is better suited.
So instead of using that icky earth destroying copper wire, it uses conductive thread. Thread is used by girls making craft projects, what an excellent correlation with the marketing campaign that only women like health and green (seriously, WTF is up with that?). Tada, conductive thread, its great!
Seriously, conductive thread is basically wire wrapping wire with yarn/thread except the connections aren't gas tight so its not as reliable. Wirewrap is great stuff, I built a 8051 based microcontroller in '91 and it still works. Its a 8052AH-BASIC which is basically a preprogrammed 8051, predating the identical concept BASIC-STAMP and more modern ARDUINO by a decade or two. Wire wrap is the opposite of automotive/industrial/aerospace grade as it is completely intolerant of vibration and moisture. Aside from that, its great. I would guess conductive thread would be the same.
Reading the articles, its a cool psuedo Manhattan style construction using little pegs and making the electrical contacts using the psuedo wirewrap thread. I like manhattan construction for experimental stuff... need another connection point? snap off a tiny piece of DS PCB and solder it to the groundplane...
Simplest similar design would be a 3-d printer that can print Kapton filament and regular ole solder paste and a hot air gun. One problem being that a lot of repraps use Kapton for their high temp parts, so you'd need something more exotic. Aside from my having no idea if Kapton is thermo-setting or thermo-plastic and being too lazy to look it up because it ain't happening anytime soon.
If you don't want to use conductive thread, silver bearing epoxy would probably work.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Not impressed. I can hand solder a circuit smaller and much cheaper on standard proto board with plated through holes. Done this many times with better results. For circuits I am going to make more than 1 or 2 of just download the free ExpressPCB program and for around $55 you can three boards.
Could they in effect print or incorporate certain components inside the PCB board?
SMD resistors are pretty small, and if they were embedded it would free up more surface area for larger components and reduce overall size.
But it will probably never work for real products. I'd never have the gall to sell an electronic product with connections made of conductive thread. I'd sooner hand-wire it together on perf board.
3D printing works if you need to make one or five objects that don't need to be very robust. But you don't have to get into very high numbers at all before it's cheaper get injection-molded custom parts that are much stronger.
You could probably do multi-plane boards with less trouble, not having to have the through holes go all the way through the board, just to connect the two planes. You could probably make multiple planes that are just resistors, or even capacitors, printed onto the substrate. They already do a lot of this stuff, I've seen boards with zig-zaggy areas that certainly appear to be resistors (not the zig zags that keep the interconnects the same length, but at right angles to each other and wrapping back onto themselves). Possibly even small transformers?
On the other hand, "conductive thread" doesn't really sound like it is going to conduct much current, so you'd probably have to have a machine that can actually print metal.
You are obviously too young to remember vacuum tubes. I have been working in electronics since the early 70's as a kid, tv shops in the mid-late 70's. I have watched circuits shrink over the years, from no circuit board (point wired tv chassis), to huge printed circuit board, to the switch over from tubes to transistors (and the RCA nuvistor), then onto LSI chips. A 25" color TV use to take two strong men to lift & move around. Now, a housewife can hang one on a wall. Given time, the 3d printing will shrink also.
Um, embedded printed resistors and capacitors have been around for decades. This "3d printing" fad is just preying on the ignorance and touching naiveté of the computer generation. You think everything just popped into existence five minutes ago and that people before were complete, drooling retards. Newsflash: PCBs have been around for decades and they are now approahcing the same density and complexity as early ICs. You think you'll be getting anywhere near that in your living room? Um, no?
Badly, almost certainly. Think of it as a poor man's wire-wrap system and make comparisons to that.
The conductive thread has a lot more resistance than real wire-wrap wire (I would have used wire-wrap wire with stripped ends instead of conductive thread for this reason alone). You don't get the gas-tight connections that you get where wire-wrap wire is pulled over the corner of a square post, so there's potential for long-term oxidation and increased resistance (to the point of appearing to be an open circuit at low voltages). Since the "wires" aren't insulated, stretching or sagging from any loss of tension runs the risk of shorting two connections. It's going to be even more prone to loosening from vibration and flexing than wire-wrap.
Actually even small quality injection molds can easily run into the multiple thousands of dollars, so while you're correct for commercial runs, for pretty much anything below that, i.e. most non-commercial parts, 3D printing is starting to look good, especially on the more robust commercial processes.
I'll grant you the strength issue - I think it'll be a while before 3D printers become competitive in that realm, though milling machines don't have that issue. The architectural school of "mass customization" is beginning to take advantage of this - it's no longer dramatically more expensive to cut custom parts from base stock than it is to cut standardized parts - it's all computer controlled and comes down to how long the cuts are and how much material is wasted do to poor component packing on the stock. Especially if a structure can be built from multiples of only a few custom pieces it can rapidly be built by a few people given a big pile of parts and lego-style assembly instructions, offsetting the higher component cost with lower assembly costs (fewer, and potentially less-skilled, man hours required)
At this point 3D printing is largely a hobbyist and prototyping tool, as is to be expected. After all it's only just starting to become affordable, and people are still exploring its potential. A few decades ago computers were in a similar sort of niche, relegated to hobbyists and research institutions. The 3D printing techniques that are being developed now are sort of the equivalent to the development of the bubble sort - poor performance, but it gets the job done, and thus expands the sphere of what's possible, allowing more hobbyists to explore a wider range of possible applications.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Any time you mention "solder", remember the temps involved and that the plastic structure used in the construction has to withstand those temperatures. Standard FR4 printed circuit board material (fiberglass reinforced, non-reversible heatset resin) is remarkably tough stuff. Even the most heat-resistant thermoplastics the industrial 3D printing suppliers are making available are questionable for standard soldering temperatures. And it's not clear that the hobbyist printers can produce the temperatures necessary to work with those higher-melting-point thermoplastics.
Newsflash: PCBs have been around for decades and they are now approahcing the same density and complexity as early ICs. You think you'll be getting anywhere near that in your living room? Um, no?
No, but the equipment to produce them costs somewhat more than the $2,000 a 3d printer will set you back, and will take up a lot more space than most people have available. Alternatively, hiring other people who already have the equipment will set you back $50 or so per board for small quantity orders.
The fact that this could possibly be done with reasonably cheap equipment that a hobbyist can feasibly afford *is* a breakthrough. Yes, it's irrelevant to the professionals who will continue to do things in the better way that requires more expensive equipment, but for the rest of us, this kind of thing is important.
(OTOH, the stuff linked in the article isn't exactly there yet...)
SMD resistors are pretty small, and if they were embedded it would free up more surface area for larger components and reduce overall size.
It's quite common to have embedded SMD capacitors inside of multi-layer PC boards. This is done to improve the transmission line characteristics of long traces.
Hey, OP here.
Anyone know anything about how this system ages and/or wears?
This is a very important point of course, because the intention is actually to build something that is production grade (obviously a ways off). But so far I have been actually pretty impressed. The durability of the plastic is extremely impressive (ABS == lego plastic, and my legos have lasted forever..) -- obviously you're mostly wondering about the durability of the circuits. Now I've only built a handful of flashlights which have only been around a few weeks (distributed to a few friends as beta testers), but so far I'm pretty impressed. They could definitely be brighter, and the ergonomics could use some work. But the circuits themselves have held up pretty well.
The conductive thread has a lot more resistance than real wire-wrap wire
But I don't understand why they're using "conductive thread" instead of fine-gauge copper wire
I have tried many types of wires, threads, glues, tapes.. but after a few types of conductive threads, I have found this to have the best properties:
http://members.shaw.ca/ubik/thread/thread.html
At 0.65 ohm / cm, there's not much of a problem with the resistance. It doesn't fray either, but it's also flexible enough to wrap easily, thread holes, tie knots and whatnot (A fine gauge wire would probably work too, but would not function in my current implementation of "slide switch").
so there's potential for long-term oxidation and increased resistance
The thread is coated in silver, so I think it's pretty resistant to that. Definitely something to watch though
Also, because it's unshielded, I anticipate a lot of problems in high frequency applications. This method just seemed like the shortest path to printable electronics (design constraint being, using only one machine and the raw materials). Obviously a lot of work needs to be done to continue to increase the scope of what is "printable".
Do the kids these day even know what wire-wrap is? That's the first thing I thought of too.
One type of prototyping PCB machine uses a 3-axis mill to cut traces into plain copper-clad boards. Got that - a 3 axis mill. All the rep-raps and such are already 3-axis machines. They just need a mill option to cut circuit boards. Not everything needs to be "additive" manufacturing. Also, once you have a mill you can cut sheet metal. That means you can now make motors (rotor and stator laminations) sans shaft. You can also cut wood or metal shapes accurately to build structures. This would go a looooong way toward self-replication. But hey, if you insist on extruding goo for *everything* it's going to be decades before you make more than plastic toys.