New Chips Loaded With Dummy Parts

http://spectrum.ieee.org/semiconductors/design/new-chips-loaded-with-dummy-parts/0

by naish • 17 years ago

61 16 17 years ago

spectrum.ieee.org

wglb• 17 years ago

Interesting. Kind of the junk DNA of chips.

NathanKP2• 17 years ago

Not really. The dummy features have a practical purpose to help the silicon deal with stress. Its similar to the ridges and lines that car manufacturers are putting on the panels of new cars. The metal is so thin on these panels that they have to put ridges to stop them from bending. The same thing has happened with processors. We have reached a point where the chips are so small that similar ridges have to incorporated to even out stress within the chip.

bmelton• 17 years ago

You might be dismissing the point too soon. To the lay-person, junk DNA looks like as useless a feature as a ridge in a door panel, or dummy pathways on a chip. To an expert auto-maker, the purpose of the panel ridges is obvious, structural rigidity. To an expert chip-maker, the purpose of dummy pathway is obvious. To Our Holy Creator Who Art in Heaven (or whomever you wish to credit our creation), it is possible that our junk DNA has a very obvious purpose that we have yet to divine.

rwmj• 17 years ago

This technique has been used in PCBs for many decades. You fill in unused parts of the PCB layers with stripes, partly to improve the manufacturing yield, and partly (in ground planes) to "debounce" the circuitry.

silvio• 17 years ago

This is an interesting case of the relationship between abundant and scarce resources. It used to be that transistors were scarce, so using the silicon in order to pack them well was the optimization goal. Nowadays, transistors reached a point of zero cost, but yield and the process nodes to make them are incredibly expensive, therefore, you get "wasted" silicon.

In programming, this is akin to programming in assembly, when no cycle can be spared, versus programming in the highest available language, when the programmer's attention and productivity is scarce.

soundsop• 17 years ago

I don't see how transistors can be zero cost and at the same time be incredibly expensive.

Without the dummy devices you actually would not be able to pack them as close, so the dummy devices actually help achieve the goal of higher density.

joezydeco2• 17 years ago

What about compilers that stick in NOPs to keep pipelines in sync?

duskwuff• 17 years ago

Less "to keep pipelines in sync" and more "to align jump targets to cache-friendly boundaries". But yes.

gcb• 17 years ago

Wooooosh ... sound over the head of a software guy reading this.

altano• 17 years ago

>Intel improved the resolution of its lithography with a technique called dipole illumination, a process that splits light into two beams, sends them through reduction lenses, and projects features from different angles.

That's so cool that someone had to figure out how to shrink LIGHT so that one can watch cats doing cute things on YouTube.

New Chips Loaded With Dummy Parts

Related Stories