Cooling gradient

Measure for the cool down rate per seconds of components respectively board assemblies. Strictly speaking, the correct unit would be Kelvin / seconds, yet most of the time, °C/s is used. For active SMT components, the permissible gradients are specified, for example, in the IPC/JEDEC-STD-020D.1 spec. For other components, the values are noted in the corresponding data sheets of the manufacturers.