Latest NewsAehr Test Systems Completes DARPA Agreement on Wafer-Level Burn-in and Test System
FREMONT, CA., January 3, 2001 - Aehr Test Systems (Nasdaq: AEHR), a leading provider of systems for burning-in and testing DRAMs and other integrated circuits, today announced it has completed a multi-year research and development agreement with the U.S. Defense Advanced Research Projects Agency (DARPA). Aehr Test entered into the $6.5M agreement to develop a Wafer-Level Burn-in and Test system as part of a DARPA initiative to develop new technologies to enable the production of Known Good Die (KGD which are unpackaged die that have been fully tested and burned-in.
A critical step in producing Known Good Die is the burn-in and testing cycle. Aehr has long produced systems for the burn-in and testing of packaged parts, but there had not been a cost effective method for burning-in unpackaged parts. The goal of the agreement was to develop a system for burning-in and testing Integrated Circuits (ICs) while they are still in wafer form. The co-funding from DARPA helped cover part of the costs of developing the new technologies required to build a wafer-level burn-in and test system.
The most difficult part was the development of the technologies necessary for burning-in and testing a whole wafer. “It definitely was a challenge”, said Don Richmond, Wafer-Level Burn-in and Test Program Manager. “Some of the challenges that we addressed were contacting tens of thousands of die pads simultaneously on a full wafer, individually controlling and testing all the die on the wafer, and keeping the temperature uniform across a wafer with a mixture of good and bad die. Our development efforts have resulted in several patent applications for our innovative work.”
“The wafer-level burn-in program has been a team effort, including partnerships with Electroglas, Inc. (Nasdaq: EGLS) in developing a full-wafer alignment system and NHK Spring Co., Ltd. in developing a full-wafer contactor,” noted Carl Buck, vice president of marketing. “Our strategy is to provide a complete solution for IC manufacturers who want to implement wafer-level burn-in and test in their production lines.”
“Without DARPA funding and support it would have been more difficult to develop all of the technologies required to make wafer-level burn-in and test feasible,” said Rhea Posedel, chairman and chief executive officer of Aehr Test. “We now look forward to the commercial introduction of a wafer-level burn-in and test system with our beta site targeted to be in the second half of calendar year 2001.”
Wafer-Level Burn-in and TestIn the normal IC production flow, an IC wafer that has completed fabrication is cut into many individual die. These die are then mounted into individual packages that can then be burned-in and tested using standard test equipment and fixtures.
The demand for smaller and smaller consumer devices, such as wireless telephones and PDAs, has led to smaller packages and even directly using bare (unpackaged) die. A common use of bare die is in the production of Multi-Chip Modules (MCMs.) MCMs have many military as well as commercial applications where a low failure rate is important.
Producing MCMs with a low failure rate is helped by using KGD. KGD are critical to the manufacturing of MCMs because of the number of die on an MCM and the difficulties in repairing an MCM. The failure rate of an MCM increases with the number of die on the MCM. Full burn-in and testing of the die prior to assembly in the MCM can have a significant impact on the yield and reliability of the MCM.
The first technology developed by Aehr Test was a process for burning in and testing individual die using a temporary, reusable package or “carrier.” The DiePak® carrier makes electrical and thermal contact with the individual die and provides a standard package form-factor for use on burn-in boards.
The wafer-level burn-in and test system moves beyond the single die to burn-in and test the full wafer. This has several advantages including the reduced labor from handling the whole wafer rather than handling all of the individual die, fewer number of steps in the test process, and increased information on failures so that the IC fabrication process can be improved.
About Aehr Test Systems
Headquartered in Fremont, California, Aehr Test Systems is a leading provider of systems for burning-in and testing DRAMs and other integrated circuits and has an installed base of more than 2,000 systems worldwide. Aehr Test has developed and introduced two innovative product families, the MTX system and DiePak carrier. The MTX is a massively parallel test system designed to reduce the cost of memory testing by performing both test and burn-in on thousands of devices simultaneously. The DiePak carrier is a reusable, temporary package that enables integrated circuit manufacturers to perform cost-effective final test and burn-in of bare die.Safe Harbor Statement
This press release includes forward looking statements within the meaning of the Securities Act of 1933, including statements regarding the timing of a commercial introduction of a wafer-level test system and statements regarding market demand for such products. Such forward-looking statements are subject to risks and uncertainties which could cause actual results to vary. Such risks and uncertainties include successful integration of all technologies into the final system, marketability of the products, and the potential emergence of alternative technologies. See the Company's 10-K and most recent 10-Q filed with the SEC for additional risks affecting the company.