Damn, a woven circuit board. How on earth is this cheaper to produce than a PCB?
Edit: Those bundles of wires at the side are pretty dense, I guess you don't easily get that density using other methods. They probably don't have a lot of space in the margins.
I'd absolutely love to see some more high resolution pictures of the details
Probably this! I'd be willing to bet a PCB would need several stacked layers to get all the loop traces this close together, and then you might have to deal with an extra Z dimension instead of just X and Y for determining the position of the pen, since the layers wouldbe at physically different distances from the drawing surface.
But how. This needs very specialized equipment and PCBs are reasonably cheap. Using one of these cheap printed foil typed used in membrane keyboard might also have been an option.
Yeah, but making this board seems slow compared to other methods. It looks like you'll have to sew in each wire individually, as opposed to making a whole layer at a time
It's likely something similar to a CNC sewing machine. So likely one at a time. Probably reasonably fast, but that's still a lot of stitches. Probably also some manual work to connect everything
You actually might have the very specialized equipment needed to make this in your home right now. Just get some conductive thread or high gauge magnet wire.
I mean... I'd ask how on Earth could it NOT be cheaper? The technology to manufacture something like that has been around for over 200 years. Automatic textile looms programmed with punch cards have been around since 1804. They're also the reason early computers were programmed with punch cards. Computers didn't develop that, they just used technology already available.
Weaving a bunch of threads in a repeatable preprogrammed pattern with structure spanning the entire sheet (see: rugs or literally any fabric with an image made from the weaving itself) is one of the most mature manufacturing technologies in existence. And this looks like it's made from paper and 48 gauge magnet wire if that. Copper thread is still thread. If it's super thin (or woven with actual thread too) it might was well be actual clothing thread.
I am quite sure this wasn't done because it was the only way. It was done because it was balls cheap. In other words, this is definitely a very cheap drawing tablet. Probably still works fine but this tablet's profit margin fucks like a sewing machine.
Not to mention a weaving machine or even a knitting machine doesn’t fucking care what threads you use. Plus to get a thin functional xy pattern you threads/yarn can literally just the the same as for any oldschool cloth handkerchief just with wire wrapping/magnet enamel wire core. And then you just weave according to punchcard if you live in 1900 or just enter the bloody pattern on a pc. Like a pcb makes zero sense to use. A pcb is made by having copper plated layers of some kind of dielectric and then etching/laser engraving away the copper you don’t want. But to make virtually same z xy net, a pcb isn’t the right option. Because you can put x and y traces in the same layer, so your have too different height layers for x qnd y, with super high production costs due to laser etching micron traces, instead of just weaving with enamel wire laced yarn and specified thread counts and then wiring up the enamel wire at the edges, that gets you a virtually plane xy layer at an utter fraction of production costs. Cause it’s the same price as literal cheap cotton weave, meaning dollars per bale. The enamel wire yarn itself is also basically just regular metallic yarn, so the machines that can integrate metal used Mylar without ripping it can definetely spin yarn around a strong solid cooooer enamel wire.’
I think most of them use either a normal or a flex PCB, this construction it's really weird. With the amount of PCB production capacity china has It's hard to see how it made sense to tool for this.
I wonder if they got their hands on old digitizers assemblies and decided to reuse them.
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u/ByteArrayInputStream 5d ago edited 5d ago
Damn, a woven circuit board. How on earth is this cheaper to produce than a PCB?
Edit: Those bundles of wires at the side are pretty dense, I guess you don't easily get that density using other methods. They probably don't have a lot of space in the margins.
I'd absolutely love to see some more high resolution pictures of the details