IBM and adhesive maker 3M are teaming up to cook up the packaging goo that will be needed to stack up chips into 3D arrays. There is a growing consensus in the computer industry that more compact and three dimensional packaging of chips is necessary to keep increasing the performance and reducing the power draw of everything …
I really wish I could skip the title - I can never think of anything witty
I am, I think, gobsmacked
Part of me is going "ooo... that's so cool!"
Part of me is going "what took them so long to think of this?"
And the rest of me is wishing I'd thought of it.
So I'm just gonna go with "damn that's cool"
Titles aren't that important.
What I think Pooka isn't to much that nobody had thought of it before. But making the architecure and adhesive is what's so tough.
It will certainly be a better patent then apple's Ipad design. I approve of this.
Correct, it's the glue!
As mentioned elsewhere, putting multiple layers in a package is already done. Even Apple's A4 has the RAM on top of the CPU ( http://www.ifixit.com/Teardown/Apple-A4-Teardown/2204/1 ). The novel part here, however, is coming up with an adhesive that serves as not only to position the parts, but also serves as the wiring kills a great many birds with one stone and shan't be easy.
I, for one, welcome our multilayered glued overlords.
Dimension Z here we come
Wait 'till they figure out how to deposit a flat layer of silicon o'ertop of a fabricated wafer. After that it's off to the races again.
+1 (makes a change doesn't it?)
It's going to make it a bit of a pig for the copycat mob
About 4 years ago Samsung doing ARM SoC, RAM and Flash, one 3mm high package, three layered chips. Doesn't work with x86. The RAM and FLASH would fry.
ARMs and Flash
Peel the top off a current SD card and you'll find there's usually an ARM7 glued to the surface of a much larger flash array. It does the SDIO interface and the initial self-test and bad block scan. The chips are wire bonded though.
The cool things about this new process are the apparent selective electrical conductivity - vertical not horizontal and that IBM are apparently routing signals out the underside of their substrates.
Depends if you
Underclock the chip stack so instead of a 4 GHz core you run it at say 900 MHz and stack the RAM and Flash in threes, so CPU0-Ram0-Flash0-CPU1-RAM1-Flash1-etc
You lose some efficiency but the real estate saved is impressive.
I can see something like this working well for Flash chips, they are notorious for drawing a lot of power and getting hot in the process.
Plus it means only the bottom chip in the stack (or top) needs bond wires which simplifies manufacturing compared to the recent 9 or 18 chip stacks where each chip needs all the bond wires connected.
IBM implemented a primitive version of this idea on the System/3 back in 1969. A 1967 patent, 3,312,878 describes the stacking of circuits, not chips, and invokes the same reasoning.
Not 3D, only 2.0001 D
A long way to go before any justifiable claim of 3D.
Fundamental issues such as yield / fault tolerance, and heat dissipation.
Wetware still has a few tricks we can't (yet?) match.
Genuinely think this is a fantastic idea but what happens when a RAM chip, for example, in the middle of the stack fails, would you have to replace the whole tower, because you couldn't break the stack, reglue and replace, that might get expensive....
When did you last have to replace a CPU or a DIMM?
Silicon chips are amazingly reliable. I see a DIMM that failed in service once or twice a year (8 or 16 chips per DIMM, 2 or 4 DIMMs per PC, about 400 PCs). And I suspect most of those failures are with the soldered joints onto the PCB, or with the connector.
I've seen a failed CPU twice in twenty-plus years. (Maybe a few of the old boxes that went straight to the scrap-heap were CPU failures rather than MoBo failures, but either way they'd lasted well into obsolescence).
At this level of reliability, a stack of 100 will still be acceptably reliable. Possibly, more so than the same 100 chips soldered onto a board (which you don't repair anyway in most cases).
Don't forget that most (genuine) enterprise kit already has lots of redundancy tricks built in to cope with broken memory (or even processors for that matter). Same way as disks actually have a whack of spare capacity above their stated amount to allow for bad block relocation. They can just build spare capacity in the stack...
Tiny holes and cables
Several companies including Intel and IBM are working on this concept of 3D silicon skyscrapers.
Puting multiple layers in the same package (what many including Apple) have done, is nothing (and very different from) compared to 3D chips.
In 3D chips, many tiny holes are 'drilled' in the silicon material through which the cabling goes from layer to layer. These 'holes' and 'cables' are microscopic. I believe somewhere in the range of Microns, but it might as well be much smaller.