Electronic assemblies with hidden dies - design support by means of FE analysis

In order to achieve high functionality and reliability and to minimise the number of later redesign loops, thermal and thermo-mechanical reliability aspects should be taken into account already from the beginning of the initial design phase of new products or for developing of a new technology. For this purpose, numerical studies by means of finite element (FE) analyses are very efficient to check the desired properties. Within the research project "Hiding Dies", funded by the European Commission, several packages with hidden dies are under construction. A special test board with different thermal test chips (TTCs) was designed regarding predicted thermal as well as thermo-mechanical properties. The authors outline their experience in supporting the design process of packages with buried dies. It proved to be imported to combine technological knowledge, experience in FEA, and a sufficiently quick response time.