Several articles have been written about the pros and cons of constant wrist-strap monitoring, ionization and various methods of ESD testing. All these issues are completely valid in today’s semiconductor factories and anywhere ESD is a factor in the reliability of the end product.
Many of the articles discuss the need for becoming ISO 9000 compliant. My understanding of ISO 9000, from an ESD point of view, is the need to document everything you are doing to control ESD in your factory.
Some of the concepts that I have read discuss several ESD-control products that are automated and ISO 9000-compatible. Currently on the market is a constant wrist-strap monitoring system that links to a computer, an overhead ionization system that operates from a personal computer, and an ESD statistical analyzer that prints data and is connected to a Faraday cup, a charge plate monitor and a personnel voltage tester.
While all these items are excellent for controlling ESD and tracking the results for ISO 9000, wouldn’t it be great if all these systems could be linked to one computer? Imagine an ESD coordinator sitting at a PC looking at what is happening with all the constant wrist-strap monitors in the factory, and then switching screens to see how the overhead ionization system is functioning in the clean room down the hall.
Furthermore, the coordinator could be conducting experiments in a lab and logging the results in the computer. All reports are generated from one computer, or several computers can be networked if other people, such as QA or management, need to monitor the information.
To take this idea one step further, consider some of the excellent portable ESD audit kits that are available and how nice it would be to log all audit results to a laptop computer. A customer could get audit results much sooner, as well as a copy of the disk for future reference.
I have visited several semiconductor manufacturing facilities and the conditions I am describing do exist. It is very common to have a clean room where parts are being assembled by one group and tested in another area of the same building. So having constant wrist-strap monitors, overhead ionization and an ESD test laboratory are real situations.
In my opinion, we need to incorporate all this equipment into one computerized system. Automation plays a major role in our factories, so why not with ESD, too?
Michael R. Hoogstra
Copyright 1995 Nelson Publishing Inc.