> researchers at the Air Force Research Laboratory and American Semiconductor recently 3D printed microcontroller SoCs from polymers on a flexible silicon substrate.
Then in the source:
"we took silicon IC chips and thinned them until they became flexible but retained their circuit functions."
So no, they did not 3D print an SoC from polymer.
Also, the chip manufacturing process is already, in a sense, additive (you deposit layers of material on each other). Unless the author is proposing printing billions of gates and wires one by one, I don't see where this is going. And if that's the case, the cost structure would exceed the traditional process many times, even if you are trying to make just a single chip.
The best actually-printed-by-an-inkjet-printer circuits I know of are simple ring oscillators of at most ten transistors or so (e.g., [1]---and they're pretty bad transistors at that), and even the simplest microcontrollers require thousands of transistors.
The paper [2] is a good review of the difficulties. Inkjet printing has at best a ≈20um minimum feature size (vs. 0.01um current transistor sizes), and the material choice is really hard: instead of silicon, you need to make semiconducting inks using funky organic molecules like 6,13‐bis(triisopropylsilylethynyl) pentacene (TIPS‐pentacene). [3] is a good recent paper trying to work around some of these limitations. So everything is still very much in the research phase.
Although inkjet printed circuits won't be anywhere near current silicon circuitry anytime soon if ever (and inkjetting transistors is the best (and kinda the only) method of 3D printing circuits we currently have), the different form factor may be useful. Circuits---even if only a few thousand transistors---could be printed on 3D geometry for interesting microfluidics capabilities, flexible circuits might make good healthcare sensors, and [4] is even studying flexible spacecraft via printed electronics for surprisingly economical space debris removal. And combining all this with 3D printed mechanical parts (via, e.g., the impressive PolyJet [5], which is basically inkjetting layers and lacks only the right materials to print electronics) will be fun.
(as to the source's Air Force Research Lab printed chips, yeah, I can't find further info, either, and agree it was probably sandpapering away most of the spare silicon bulk of an integrated circuit [impressive, useful, but not printing])
> Unless the author is proposing printing billions of gates and wires one by one ...
Just to point out, it wouldn't necessarily have to be in the "one by one" serial kind of approach of FDM 3d printing.
Something like the "one whole layer at a time" patterning approach of Stereolithography (SLA) 3D printers might turn out to work.
The closing piece of the article does say:
The future of 3D printing integrated circuits will likely
adapt a photolithography process or functional self-assembly
process to produce integrated circuits with competitive
resolution.
In a sense it is "additive", they're adding a CPU ... but then that's just what a pick and place machine does - it's how we've made PCBs for decades now
Then in the source:
"we took silicon IC chips and thinned them until they became flexible but retained their circuit functions."
So no, they did not 3D print an SoC from polymer.
Also, the chip manufacturing process is already, in a sense, additive (you deposit layers of material on each other). Unless the author is proposing printing billions of gates and wires one by one, I don't see where this is going. And if that's the case, the cost structure would exceed the traditional process many times, even if you are trying to make just a single chip.