STATS Introduces Thermally - Enhanced Version of PBGA Package; New XDPBGA Features Patented Heat Dissipation Technology.

Business Editors/High-Tech Writers

SINGAPORE & MILPITAS, Calif.--(BUSINESS WIRE)--May 22, 2002

ST Assembly Test Services Ltd. ("STATS") -- (Nasdaq:STTS) and (SGX:ST Assembly), a leading independent semiconductor test and advanced packaging service provider, has introduced an enhanced version of its popular Plastic Ball Grid Array (PBGA) package. Called Exposed Drop In Heat Spreader Plastic Ball Grid Array (XDPBGA), this new package offers improved thermal performance at a lower cost compared with traditional die-down packages.

Dr. B J Han, STATS Chief Technology Officer, said, "As devices move to higher speed, heat dissipation of individual ICs becomes a challenge. XDPBGA offers an attractive alternative for devices that require intermediate heat dissipation without the expense of traditional die-down packages. It's a great package that effectively combines cost and performance."

The new XDPBGA package fits a range of applications in telecommunications, computing and peripherals, wireless networking and digital consumer. Its thermal characteristic makes it ideal for use in laser printers, PC chipsets and graphic processors, microprocessors, set top boxes, game consoles and Gigabit Ethernet. Featuring an exposed drop-in heat spreader, XDPBGA has the same flexible size range of 19mm x 19mm to 40mm x 40mm as the traditional PBGA package. Offering a 20% improvement in thermal performance over a standard PBGA package, the XDPBGA is ready for production from the second quarter of 2002.

To support the launch of XDPBGA, STATS has licensed to use the semiconductor heat dissipation technology patented by the Industrial Technology Research Institute (ITRI). Located in Hsinchu Valley, Taiwan, ITRI was founded by The Republic of China's Ministry of Economic Affairs and is dedicated to applied research and technical service. Among the pioneering work the Institute has done is the widely adopted thermal and electrical PBGA technology licensed to STATS.

"The ITRI heat slug technology is one of the building blocks in STATS' long term plan towards providing customers with a total solution to all their backend semiconductor requirements," explains Han. He added, "With the launch of XDPBGA, STATS will further strengthen our support for customers through a significantly expanded portfolio of packages, covering the very high end, high performance devices, to the lower end, more economical devices. This reflects our commitment to continually find creative ways to provide the total one-stop solution which customers increasingly seek."

About ST Assembly Test Services Ltd. (STATS)

ST Assembly Test Services ("STATS" - NNM:STTS and SGX:ST Assembly), is a leading semiconductor test and assembly service provider to fabless companies, integrated device manufacturers and wafer foundries. With its principal operations in Singapore and global operations in the United States, United Kingdom, Germany, Japan and Taiwan, STATS offers full back-end turnkey solutions to customers worldwide. STATS' expertise is in testing mixed-signal semiconductors, which are extensively used in fast growing communications applications such as data networking, broadband and mobile communications. STATS also offers advanced assembly services and has developed a wide array of traditional and advanced leadframe and laminate based products, including various ball grid array packages to serve some of the world's technological leaders. STATS was listed on the Nasdaq National Market and The Singapore Exchange in January 2000 and is in the Morgan Stanley Capital International (MSCI) Index and the Straits Times Industrial Index. Further information is available at www.stts.com.

Certain of the statements in this press release are forward-looking statements that involve a number of risks and uncertainties that could cause actual results to differ materially. Factors that could cause actual results to differ include general business and economic conditions and the state of the semiconductor industry; demand for end-use applications products such as communications equipment and personal computers; reliance on a small group of principal customers; decisions by customers to discontinue outsourcing of test and assembly services; changes in customer order patterns; rescheduling or canceling of customer orders; changes in product mix; capacity utilization; level of competition; pricing pressures including declines in average selling prices; continued success in technological innovations; delays in acquiring or installing new equipment; shortages in supply of key components; availability of financing; exchange rate fluctuations; litigation and other risks described from time to time in the Company's SEC filings, including its annual report on Form 20-F dated February 28, 2002. We undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.