Copper Facts: Electronics

IBM and others are using copper instead of aluminum in the most powerful computer chips they manufacture. Because of copper's superior electrical conductivity, this technology enables conductor channel lengths and widths to be significantly reduced. The result is much faster operating speeds and greater circuit integration - 400 million transistors can be packed onto a single chip. Power requirements are now reduced to less than 1.8 volts, and the chips run cooler than ever before.

The use of copper conductors in the chip is the last link in a now unbroken copper chain comprising the electronic data path between user and computer. From external cables and connectors to bus ways to printed circuit boards, sockets and leadframes, it's all copper.

Since their invention early in this century, electron tubes have depended on copper and copper alloys for their internal components. In spite of the dominance of semiconductors, some $2 billion worth of vacuum tubes are manufactured annually. They include the cathode ray tubes used in TVs and computer monitors, voltage rectifiers, audio and video amplification and broadcast applications, and the magnetrons in microwave ovens.

Radio and television signals are carried to transmission antennas by hollow conduits called wave-guides. Wave-guides made of oxygen-free, high-conductivity copper are 30% to 40% more efficient than their aluminum counterparts.

The National Security Agency buildings at Ft. Meade, Maryland, are sheathed with copper to prevent unauthorized snooping. Even the windows are fitted with copper screens. The copper blocks radio waves from penetrating into or escaping from the spy operation. Copper sheathing is also used in hospitals to enclose rooms containing sensitive equipment like CAT scan, MRI and X-ray units to prevent problems related to the entrance or emission of errant electromagnetic radiation.

On a smaller scale, copper strip is used to shroud electron tubes, transistors, integrated circuits and even complete electronic chasses to prevent radio frequency (RF) interference.

Most electronic components generate heat which can cause them to age and fail prematurely. This is especially true for today's highly integrated microprocessors (computer chips). Copper's thermal conductivity, or capacity to conduct heat, is about 60 percent greater than that of aluminum, so copper can remove much more heat more quickly. The more heat removed from the processor, the more efficiently it will operate, with less potential for damage to other critical components.

Copper is used to enhance new radio frequency identification (RFID) technology used for security, tracking and purchasing systems in retail, manufacturing, transportation and distribution. For example, gas stations use RFID to allow customers to pay at the pump with a small wand that holds their credit card information. Copper increases the distance at which this "invisible" technology will work.

Most printed circuit boards for electronic products are made by laminating a sheet of copper onto a flexible film and then etching away much of the copper to leave thin lines of solid copper that carry current. A new method uses inkjet technology to deposit only thin copper lines onto the circuit, eliminating waste and making circuits less expensive to produce.