Reliability of highly integrated ceramic/polymer-based functional systems for electronic applications - Implementation of an homogenization methodology into a temperature cycling test simulation of a ceramic-based daisy chain system

summary research report - contract. research

English

This work introduces a methodology on how to incorporate complex inner metallic structure of LTCC (eventually PCB) components into an FE model in order to capture its influence on the surrounding critical parts such as solder joints or attached electronic components. To this end a homogenization technique, combining properties of several materials into effective properties of one “artificial” material, was utilized. For each element of the FE model, the effective elastic and thermal properties, obtained based upon the volume content of silver (eventually other material) in the volume of a given finite element, were calculated and prescribed. To demonstrate and quantify the influence of such homogenized properties of LTCC structure on the surrounding components, both versions of the LTCC components, i.e. bulk and homogenized, were subsequently subjected to the thermal cycle loading . The results show that the thermal cycle simulation of the system containing an LTCC with (i) bulk and (ii) homogenized properties deliver the same position of the critical solder joint between PCB and LTCC component. Nevertheless, significant stresses are induced inside the LTCC component considering the internal metallization, which might be responsible for its earlier failure in comparison with predictions made just based upon the bulk LTCC model.

Homogenization, solder joint, creep behaviour, FE analysis, thermal loading.

ŠEVEČEK, O.

30. 10. 2017

17