Advanced Semiconductor Engineering (ASE) and Siliconware Precision Industries (SPIL) have both stated that they will stop ramping up capacity for copper wire-bonding. Instead, raising utilization rates at existing copper wire-bonding lines will be a major focus for both IC packaging and testing houses in 2013.

ASE and SPIL collectively grab an almost 90% market share in the world's copper wire-bonding packaging segment. They held their respective quarterly investors meetings yesterday (January 30).

ASE revealed that the company currently has no plans to allocate any portion of its capex to copper wire bonding. The firm had been expanding capacity for the packaging technology over the previous two to three years.

ASE will be focusing its investment on packaging technologies for 28nm manufacturing processes, such as an advanced flip-chip packaging technology, in 2013, company COO Tien Wu indicated. Wu added that once 28nm becomes mature, wire-bonding packaging will be more favorable. Currently, only 20% of the overall demand for 28nm chips use wire-bonding packaging.

Wu pointed out that ASE's wire-bonding packaging business will put an emphasis on the process scalability and stability. Unlike traditional wire bonding, ASE is looking to enhance its wire-bonding technology to satisfy demand for system-in-packae (SiP) applications, Wu said.

Fellow firm SPIL noted that the company will focus its resources on silver-alloy wire-bonding in 2013, while continuing to improve its capacity utilization rate for copper wire-bonding packaging. The efforts are aimed at lifting SPIL's average gross margin, the company said.

At SPIL's Suzhou plant in China, copper and silver-alloy wire bonding now accounts for more than 90% of the total wire-bonding packaging revenues generated, company chairman Bough Lin disclosed. SPIL is looking to promote its silver-alloy wire-bonding business in Taiwan's IC industry in 2013, Lin indicated.

Copper wire bonding itself will account for 65% of SPIL's overall wire-bonding sales in the first quarter of 2013, said Lin, adding that the proportion will climb further to 70-80% later this year.