Fujitsu goes “paperless”

Durham, England–DRAM manufacturer Fujitsu Microelectronics, Ltd. of Japan needed to replace its paper-run card system for lot tracking. “Paper is a contaminant in your cleanroom,” says Chris Ayers, a systems engineer responsible for all of Fujitsu`s computer requirements. “No matter how high the quality of the paper, it will produce some level of shedding, which is unacceptable.” Ayers adds that the integrity of the data entered by operators tends to be suspect also. Also, as paper deteriorates, numbers can become smudged or even erased.

A bulk fab producing over 2.5 million 4-Mbyte DRAM wafer equivalents per month, Fujitsu then sends them to its Ireland facility for further processing, testing and assembly into chip packages. Finally, the wafers are shipped to the company`s internal sales division in Buchschlagg, Germany. From here, they are distributed to a wide array of markets, including the European workstation market, the SIMMS market and a variety of players in the European manufacturing arena.

To solve its paper problem, Fujitsu decided to install a manufacturing execution system from PROMIS Systems Corp. (Nashua, NH), which had been installed several years ago in all the company`s fabs with considerable success.

The PROMIS systems were able to control the entire product manufacturing and quality cycle. A modular system that works well in open system environments, PROMIS can operate on OpenVMS, Digital UNIX and HP/UX systems. Fujitsu runs PROMIS on two Digital 4000/500 Micro VAXs, with 21 gigs of disk storage and 348 MB RAM in each. With 181 current licensed users, the plant has over one hundred VT420 text-only terminals in the cleanroom, one terminal per inspection machine–for data entry. Major areas of implementation are equipment management, machine SPC, full-lot tracking and product SPC.