By Jay Duncombe, Intersil; Eric Madera, Linear Technologies; John Brooks, Daniel Cicero, Dr. Steven Hatch, Brian Jenkins, Kevin Olson and Barry Carroll, Nalco Company

ABSTRACT

Cooling towers play a critical role in the microelectronics industry.  Their support of the HVAC (heating, ventilating and air-conditioning) systems and ultimately the Process Cooling Water (PCW) system is necessary to maintain a consistent manufacturing environment.  Loss of this cooling capacity means fab shutdown and production loss.

Microelectronics manufacturing facilities are often located in regions where water is expensive, of less-than-optimum quality, or both.  Conversely, the microelectronics manufacturing process requires large quantities of process water.  Many of the rejected process streams are of sufficient quality to be used in the cooling tower as part of an overall water re-use strategy. The challenge resides in the development and implementation of that strategy, incorporating robust risk mitigation to protect the fab's high value production process and HVAC equipment.

A new cooling water control technology is in use at several fabs as part of their water re-use strategy.  This paper describes the common challenges, pros and cons of different solutions, and how this new technology has been deployed at two microelectronics fabs.  Case studies detailing before and after examples, ROI and performance data are presented.