May 30, 2012 - ACN Newswire -- New Japan Radio Co. Ltd. adopted Tanaka Denshi Kogyo KK’s "CHA" thick copper bonding wire for packaging its aluminum-electrode semiconductor chips. This marks the first mass production of power semiconductors packaged with copper wire interconnects, the companies report.

New Japan Radio aims for high reliability and low environmental impact with its high voltage/large current semiconductors, which are used in industrial equipment, electric vehicles (EV), hybrid electric vehicles (HEV) and smart grid power transmission.

The company researched thick copper wire as a replacement for thick aluminum wire before adopting CHA. Tanaka Denshi Kogyo uses special processes and annealing for a uniform placement of microcrystal grain in the copper wire. CHA can raise the electrical conductivity of second-level interconnects by approximately 40% compared to aluminum of the same wire diameter. CHA also can be implemented at 200µm diameter for comparable performance to 300µm aluminum wire. CHA exceeded 5000 temperature cycles in reliability testing, as compared to 2000 for aluminum wire. Whereas the thermal conductivity of aluminum is 238W/mK, the thermal conductivity of copper is higher at 397W/mK.

Copper bonding wire can support higher voltages and larger currents than aluminum wire, but typically damages bonding pads on aluminum electrodes. New Japan Radio worked with Tanaka Denshi Kogyo and bonding equipment manufacturer Ultrasonic Engineering Co. Ltd. to implement a wedge bonding technology that directly places the 200µm-diameter copper wire onto the aluminum electrodes of semiconductor chips in mass production.

New Japan Radio will primarily apply this technology to power devices, and will actively conduct product development with the aid of Tanaka Denshi Kogyo.

Tanaka Denshi Kogyo 's "CHA" thick copper wire was released in January 2012 to replace thick aluminum wire in high-current power semiconductor packaging. Also read: Tanaka establishes copper bonding wire production in Taiwan

Tanaka Denshi Kogyo K.K. manufactures a portfolio of bonding wire in the Tanaka Precious Metals Group, with TANAKA HOLDINGS Co., Ltd. as its holding company. Website: http://www.tanaka-bondingwire.com/.

Japan Radio Co., Ltd. makes semiconductors, microwave tubes and peripherals, and microwave application products. Website: http://www.njr.co.jp/

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