Advanced Semiconductor Engineering (ASE) and Siliconware Precision Industries (SPIL) both have reported decreased sales for February, but their sales are expected to gain momentum in March, powered by rising demand for high-end flip chip packaging services, according to industry sources.

ASE posted revenues of NT$14.43 billion (US$485.94 million) for February, down 13.1% on month but up 1.8%. For the first two months of 2013, revenues totaled NT$31.04 billion, increasing 11.9% from a year earlier.

SPIL's February sales of NT$4.25 billion were down 7.6% sequentially and 9.4% on year. Accumulated revenues for the January-February period amounted to NT$8.85 billion, decreasing 7.6% from a year ago.

ASE operated at 75-80% of its capacity in February, but the company expects its capacity utilization rate to top 80% in March. However, ASE still maintains its guidance for a 10-13% sequential drop for its IC backend services and sales of packaging materials in the first quarter.