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It Doesn't Take Long to Discover the Benefits of Liquid Nitrogen for Your Environmental Testing Electronic Components
 Air Products has always been at the forefront of research and development in cryogenics. Our Global research centres and our Commercial Technology Groups throughout the world actively invest time and money into new applications.
Nitrogen is a natural substance which forms about 78% of air. When liquefied, it has a refrigerating potential down to –320°F (–196°C). More and more companies are finding it a faster and more efficient way of screening and testing their electronic components.
Why choose liquid nitrogen?
Cools faster than other methods
If you require very low temperature testing or fast cycling, you should be using liquid nitrogen. Cooling speeds of up to 1°C per second can be achieved with ease. In mechanically cooled chambers, large, expensive compressors would be needed for comparable performance.
Cost-effective
The savings achieved when using liquid nitrogen are clear, particularly with multiple chamber installations. The electrical energy used for the cooling cycle is reduced, maintenance costs are lowered and there is no need for highly skilled refrigeration engineers.
Impressive space savings
The chambers that use the liquid nitrogen for cooling are extremely compact. Also, with the liquid nitrogen being stored externally, extra floor space is available for useful production. Liquid nitrogen is often already available on many component manufacturers sites, thus reducing the requirements for additional tank installations.
Provides a clean dry atmosphere
Liquid nitrogen, with less than 2 parts per million water content, is inherently dry and therefore reduces the exposure of your products to moisture contamination.
Environmentally friendly
The legislation on the use of CFC refrigerant gases will affect most companies. With liquid nitrogen, these issues will not be a problem as it is CFC-free. The noise and heat pollution normally associated with mechanical cooling is also eliminated.
Simple and convenient to use
An Air Products tanker delivers the liquid nitrogen to your premises and fills the on-site vacuum insulated storage vessel. No pump or any other external equipment is required, as the liquid nitrogen is transferred by the pressure in the storage vessel. The entire installation is engineered by Air Products to maximize the super cold potential of liquid nitrogen at the use point. Once in the test chamber, the liquid nitrogen is dispersed by a circulation fan. The cooling results from a combination of the latent heat of the liquid as it vaporizes and the sensible heat of the resultant cold gas. The control system then regulates the flow to achieve the required temperature. The spent nitrogen gas is safely exhausted to the outside where it mixes back into the atmospheric air.
Can be tailored to the customer's individual requirements
The purity of Air Products' gases and our timely deliveries are specifically tailored to meet your needs. Whether you are performing environmental stress screening of assembled components for potential failure or taking part in regular inspection testing, liquid nitrogen fits in with the way you work. If required, we can even advise you on the most cost-effective way to convert your existing cooling method over to liquid nitrogen. With liquid nitrogen installed in your company, Air Products can offer Service+, our complete after-sales support, technical expertise and much more.
Environmental stress screening (ESS) refers to the process of exposing a newly manufactured product or component (typically electronic) to stresses such as thermal cycling and vibration in order to force latent defects to manifest themselves by failure during the screening process. The surviving population, upon completion of screening, can be assumed to have a higher reliability than a similar unscreened population.
An ESS system usually consists of a test chamber, controller, interconnect and wiring, and a functional tester. These systems can be purchased from a variety of companies in the environmental test industry.
Climatic and Environmental stress screening (ESS), HASS and HALT
Increasingly there is the need to test products at high temperature and humidity change rates. ESS chambers cooled with liquid nitrogen have temperature change rates of 5K/min, 10K/min and 15K/min. For special applications change rates of up to 30K/min can be provided and these chambers are normally used in highly accelerated life testing (HALT) and highly accelerated stress screening (HASS). |
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