HSINCHU, Taiwan, February 24, 2005 - UMC, a world leading semiconductor foundry (NYSE: UMC, TAIEX: 2303), and JMicron Technology Corp. today announced that JMicron's Serial ATA (SATA) II PHY Technology has been developed and proven on UMC's 0.13um HS (High Speed) process. The SATA 3.0/1.5 Gbps physical layer (PHY) intellectual property (IP) core is designed to interface with SATA devices that comply with the SATA 2.0 specification, and builds upon the two companies' mass production success of JMicron's 0.18um Serial ATA 1.5/3.0 Gbps PHY IP at UMC. This experience contributed to the first pass silicon success of the 0.13um SATA II IP core, with tape-out taking only 20 days for the joint R&D team to complete.

"UMC constantly enhances its SoC foundry solutions portfolio to provide the enabling resources that designers need to launch their SoC products in a timely fashion," said Ken Liou, director of the IP Development & Design Support Division at UMC. "JMicron's SATA PHY core is a welcome addition to our IP portfolio as our customers can build it into their next-generation ICs for greater compatibility with the newest serial ATA specification."

"As High Speed Serial Link core technologies are gradually applied to computer, communication and consumer products, IC designers are facing greater challenges as they strive to develop their specialty-core technologies while trying to keep pace with ever-changing interface technologies," said Tim Liu, president of JMicron. "By making our product available through UMC, designers can more readily develop their 0.13 micron SoCs to be Serial ATA II PHY (3.0 Gbps) compatible. Also, customers will have greater confidence as this is our second product designed with UMC."

For more information regarding JMicron's core authorization programs, please visit JMicron's website (www.jmicron.com) or contact sales@jmicron.com.

UMC (NYSE: UMC, TSE: 2303) is a leading global semiconductor foundry that manufactures advanced process ICs for applications spanning every major sector of the semiconductor industry. UMC delivers cutting-edge foundry technologies that enable sophisticated system-on-chip (SOC) designs, including 90nm copper, 0.13um copper, and mixed signal/RFCMOS. UMC is also a leader in 300mm manufacturing; Fab 12A in Taiwan and Singapore-based UMCi are both in volume production for a variety of customer products. UMC employs over 10,500 people worldwide and has offices in Taiwan, Japan, Singapore, Europe, and the United States. UMC can be found on the web at http://www.umc.com.

JMicron was founded in 2001. JMicron has a head office in Hsinchu Science Park, Hsinchu, as well as a research center in Irvine, U.S.A. The main product research direction focuses on the High Speed Serial Link, where the technology can be broadly applied to Serial ATA, PCI Express, USB and relative products. JMicron is also a part of UMC's Gold-IP program.

Some of the statements in the foregoing announcement are forward looking within the meaning of the U.S. Federal Securities laws, including statements about future outsourcing, wafer capacity, technologies, business relationships and market conditions. Investors are cautioned that actual events and results could differ materially from these statements as a result of a variety of factors, including conditions in the overall semiconductor market and economy; acceptance and demand for products from UMC; and technological and development risks.