Taiwan-based IC design house Mediatek will boost orders to United Microelectronics Corporation (UMC) by about 150% this quarter, overtaking Xilinx as UMC’s biggest customer, sources said. To replenish inventory of optical storage drive ICs and meet Christmas demand for DVD player chips, Mediatek’s orders to UMC will jump from about 12,000 wafers per month in the third quarter to 30,000 wafers per month this quarter, according to sources.

Consequently, UMC’s utilization rate on some production lines will rise from 50% in the third quarter to 70% this quarter, they said.

Meanwhile, Xilinx’s orders to UMC have fallen from about 15,000 wafers per month early this year to around 10,000 wafers per month this quarter. In addition, it may need at least a quarter to clear inventories, which have built up to about 3.5 months’ worth in the third quarter from 2.5 months in the second quarter, sources added.

Over the past four or five years, Mediatek has mainly used 0.25-micron technology at UMC’s Fab 8A and 8B. It transferred a portion of production to Fab 8E this year.