CPU is a well-known acronym in the computing world, but what is in them? Learn more about CPUs, including the differences between Pentium and Celeron processors, or how graphics cards work.

Can computer chips be air-conditioned?

It takes a pretty big AC unit to lower the temperature of your entire house or apartment. And while you may not think about keeping your computer cool, it can overheat, too. Is there an air conditioner small enough to cool a computer chip?

During the hot months of summer, many people stay indoors in order to avoid sweat and sunburns, enjoying the cool comforts of an air-conditioned apartment or house instead. While a room without any cooling system would feel stuffy and uncomfortable, air conditioners provide us with comfortable, 70-degree temperatures.

The air conditioner in your living space works just like the refrigerator in your kitchen -- it uses similar liquids, gases and cooling systems to create cooler temperatures. Instead of simply circulating air around like a fan, both technologies work by actually removing heat from a specified area. A compressor compresses the cool gas known as a refrigerant, causing it to become hot. The hot gas runs through a set of hot coils and condenses into a liquid until it reaches an expansion valve. The valve turns the liquid back into a cool gas by evaporating it; the gas then runs through another set of coils. This second set of cooled coils, facing the area that needs to be air-conditioned, absorbs any warm air to cool down an apartment -- or refrigerator.

The big difference, of course, is that the cooling system in your refrigerator is a small, enclosed box. Once closed, the door traps cool air inside to keep food and drinks fresh for long periods of time. An apartment's air conditioner, on the other hand, is responsible for cooling a much larger space. The walls and doors of the apartment act like the refrigerator door, keeping the cool air from escaping.

But what if engineers took the technology used in air conditioners and applied it to a much smaller scale -- a micro scale, for instance? Scientists working at the Purdue University of Mechanical Engineering, led by Professor Issam Mudawar, are developing an experimental system that takes cooling techniques from air-conditioning systems to cool down small, hard-working computer chips.

­How does an air-conditioned computer chip work, especially on such a small scale? Will you soon find air-conditioning systems in personal computers, or do computers even get hot enough to require such an efficient technology? If not, what kinds of computer chips actually need to be air-conditioned?

How EUVL Chipmaking Works

Silicon microprocessors are about to reach the limit to their storage capacity. But one technology may extend the life of the silicon microchip -- it's called extreme-ultraviolet lithography, and it may keep silicon useful for a few years longer.

­Silicon has been the heart of the world's technology boom for nearly half a century, but microprocessor manufacturers have all but squeezed the life out of it. The current technology used to make microprocessors will begin to reach its limit around 2005. At that time, chipmakers will have to look to other technologies to cram more transistors onto silicon to create more powerful chips. Many are already looking at extreme-ultraviolet lithography (EUVL) as a way to extend the life of silicon at least until the end of the decade.

The current process used to pack more and more transistors onto a chip is called deep-ultraviolet lithography, which is a photography-like technique that focuses light through lenses to carve circuit patterns on silicon wafers. Manufacturers are concerned that this technique might soon be problematic as the laws of physics intervene.­

­ Using extreme-ultraviolet (EUV) light to carve transistors in silicon wafers will lead to microprocessors that are up to 100 times faster than today's most powerful chips, and to memory chips with similar increases in storage capacity. In this article, you will learn about the current lithography technique used to make chips, and how EUVL will squeeze even more transistors onto chips beginning around 2007.