The press-pack power module with multi-chip layout has drawn increasing attention from industry and academia with its thermal analysis becoming an essential issue. However

the pressure-dependent thermal variables

such as thermal contact resistance and thermal coupling resistance

are often neglected. In this paper

a pressure-dependent thermal network model is developed to characterize the thermal performance and mechanical status of press-pack power modules. By including the thermal contact resistance and thermal coupling resistance as the function of pressure

the proposed model ensures a more precise thermo-mechanical evaluation inside the press-pack power module. The influence of pressure on self-heating effects and thermal coupling effects of power modules is studied using the knowledge of elastic mechanics. A press-pack prototype with variable pressure loads is assembled. Then

thermal experiments under different pressures on chips are conducted and the pressure-variable temperature responses of the thermal network are measured. Consequently

the feasibility of the proposed thermal network model is validated. A cost-effective prognostic method on the mechanical status of press-pack power module is also achieved.