What’s a Couplate? The Stepping Stone to Integrated Circuits

We are spoiled these days because you can shop online and get all manner of inexpensive electronic goodies shipped to your door. This is due to the fantastic electronic fabrication workflow that has grown into a global powerhouse, facilitated by complex yet inexpensive integrated circuits! But it took a few intermediate steps to get here, and one of those is known as a couplate.

When I was a kid, the big deal was to find an old radio in the trash. You could spend a few hours stripping all sorts of parts from the thing and add it to your collection for a future project. Of course, old radios from the 1970s and earlier had a lot of the usual parts we use today, even though many of them were bigger — no surface mount parts yet. Since older radios were the usual find in a dumpster, tubes were common but you could find some transistor radios.

Once in a while something older. There would be a little box with some wires poking hiding in an old radio from the 1940s or 1950s (too early for ICs). In a way, though, these were predecessors to the Integrated Circuit and they went by a few names, depending on who sold them. PEC (Printed Electronic Circuit), a couplate, or a BulPlate, are all names for hardware that was a stepping stone between discrete circuitry and ICs.

Continue reading “What’s a Couplate? The Stepping Stone to Integrated Circuits”

Printing circuitry on a RepRap

Over on the RepRap blog, [Rhys] has been experimenting with molten metal to build circuits with the RepRap.

Last June, [Rhys] found a neat alloy made of Tin, Bismuth, and a little bit of Indium that melts at around 130° C, and has just the right properties to be extruded with a standard RepRap setup. The results were encouraging, but the molten metal quickly dissolved the brass and aluminum nozzles [Rhys] was pushing liquid metal through.

The solution to this problem was solved by anodizing the heck out of a RepRap nozzle to make a hard, protective oxide layer. Already [Rhys] has logged hundreds of hours squirting molten metal out of his RepRap with no signs of any damage to the nozzle.

Since [Rhys] figured out how to print in metal, he whipped up an extremely minimal Sanguino board. You can see this RepRapped PCB running a LED blink program after the break. Now to work on the RepRap pick and place…

Continue reading “Printing circuitry on a RepRap”