TSMC Extends its Adoption of Yield Dynamics’Genesis Yield Improvement and Data Mining Platform

Sunnyvale, CA – April 27, 2004 – Yield Dynamics, Inc. (“YDI”) announced today that Taiwan Semiconductor Manufacturing Company Ltd. (“TSMC”; NYSE: TSM) has extended its deployment of YDI’s Genesis yield improvement and data mining platform by purchasing additional floating software licenses.

TSMC originally purchased Genesis in 2002 for use in its 0.13um technology yield improvement, and has benefited particularly from the use of YDI’s patented Yield Mine® data mining software. The software has been proven at multiple world leading companies such as TSMC to rapidly analyze massive amounts of data collected in the semiconductor production process, and quickly determine what manufacturing conditions such as equipment, equipment flows, process integration steps, and design attributes are causing yield degradations.

Y. P. Chin, TSMC’s Senior Director of Product Engineering, commented, “As TSMC continues to deploy the most advanced semiconductor fabrication techniques such as 90 nm, it becomes essential to quickly achieve and maintain production quality yields in order to provide the greatest value for our customers. The Yield Mine® of Genesis tool has proved to be one of the most effective tools that helps TSMC to rapidly and effectively determine yield-limiting production factors, enhancing our yield improvement efforts in conjunction with our internal methodologies, and therefore we have decided to continue our investment in the product.”

Dr. Jonathan Buckheit, YDI’s President and CEO, added, “Our yield improvement software platform has consistently delivered value to multiple market leaders in the semiconductor industry, and as the world’s largest semiconductor foundry, we are excited that TSMC has chosen to expand our product’s role in their yield maximization strategies.”

About TSMC

TSMC is the world's largest dedicated semiconductor foundry, providing the industry's leading process technology and the foundry industry's largest portfolio of process-proven library, IP, design tools and reference flows. The company operates one advanced 300mm wafer fab, five eight-inch fabs and one six-inch wafer fab. TSMC also has substantial capacity commitments at venture fab SSMC and at its wholly-owned subsidiary, WaferTech. TSMC’s Nexsys Technology for SoC describes a suite of semiconductor process technologies and foundry services used in advanced technology semiconductor manufacturing. TSMC's corporate headquarters are in Hsinchu, Taiwan. For more information about TSMC see http://www.tsmc.com.

About Yield Dynamics, Inc.

Headquartered in Sunnyvale, Calif., Yield Dynamics, Inc. is the leading provider of enterprise yield management and advanced process control software for semiconductor and flat panel display (FPD) manufacturers, as well as fabless chip design companies. The company’s extensible software platform enables customers to quickly identify and correct semiconductor and FPD production failures, achieving faster product ramps and higher yields. Additional information about Yield Dynamics can be found at http://www.ydyn.com or by calling (408) 773-3100.

Trademarks

Yield Dynamics, Genesis, and Yield Mine are trademarks or registered trademarks of Yield Dynamics, Inc.

For further information, contact:

Homi Fatemi Yield Dynamics, Inc. (408) 773-7831 homi@ydyn.com