What sort of chamber would I need in order to carry out thermal stress screening?
An effective thermal stress screen requires a specialist piece of equipment capable of very fast temperature transitions of up to 100°C per minute. This is quite beyond the scope of standard off-the-shelf equipment. Liquid nitrogen is used to provide the rapid cooling capability and open element heaters provide the fast response when heating. Powerful fans would be employed to provide high airflow velocity around the products with careful consideration given to even distribution of the conditioned air throughout the working volume of the chamber. This is important in order to achieve the same level of screening to all the products inside the chamber. There is also an optimal chamber volume of around 700 – 800 litres in order to keep the internal chamber mass to a minimum. It is unlikely that the desired temperature ramp rates will be achieved in a chamber of more than 1000 litres.
