Measurement of Internal Stresses in Encapsulated Electronic Modules

The development of a hydrostatically-pressure sensitive transducer with dimensions much smaller than conventional pigtailed electronic components has made possible the measurement of environmentally-induced stresses in encapsulated electronic modules. Such measurements for a few encapsulants have shown large changes in internal stresses with small changes in ambient temperature, a shift in the stress transition range with formulation variations and changes in stress magnitude with component density in an electronic module.