United Test and Assembly Center (UTAC) has seen sales generated from copper wire bonding account for 20% of its total revenues, according to company CEO Lee Joon Chung. Apart from suppliers of automotive- and medical-use related chips, and discrete ICs, Lee believes the remaining chip companies will move towards copper wire process for their products.

UTAC is moving faster than Advanced Semiconductor Engineering (ASE) and Siliconware Precision Industries (SPIL) in the copper wire segment.

ASE revealed at its most recent investors conference that sales generated from copper wire bonding would account for 20% of its overall revenues by the end of 2010. ASE said it is sampling copper wire technology to more than 100 customers for design-in, and is shipping packaged ICs processed with copper wire bonding to about 65 customers.

SPIL chairman Bough Lin was quoted in previous reports saying the company looks to adopt copper processing for all of its wirebonding production in 2011.

As the cost of gold wire bonding is on the rise, more IC assembly and test service providers consider copper wire as an alternative in low-pin-count devices such as consumer- and handset-use ICs.

The price of gold climbed to US$1,249.40 per ounce on the London Bullion Market last Friday (May 14, 2010), an all-time high.