A SAFETY SYSTEM FOR DYNAMIC VACUUM LIQUID NITROGEN PIPELINE: For World Class Manufacturing Operation in Semiconductor Industry

摘要

Liquid nitrogen is a colourless, odourless, extremely cold liquid and gas under pressure. It can cause rapid suffocation when concentrations are sufficient to reduce oxygen levels below 19.5%. Contact with liquid or cold vapors can cause severe frostbite. One volume of liquid nitrogen will expand to produce 696.5 equivalent volumes of gas. With this background Ln2 is being used in Semiconductor industry especially in testing operation. The cold tests are taken on products at a temp up to -40C to -60C. The Ln2 is used in testing machine to reduce test handler chamber temp. The chamber temp is required to maintain at -40C with allowance of + or - 3C to get accurate results. So this paper describes how Dynamic Vacuum ln2 pipeline system can be maintained smartly to get maximum benefits with minimum unscheduled shutdown in semiconductor industry. This paper also gives the details about the safety system developed at SPANSION Thailand limited for handling of ln2 through Dynamic vacuum ln2 pipeline system.