Study of temperature dependent properties of organic substrate materials

This paper presents a novel approach in electronics packaging for high temperature environments of automotive applications. Especially electronics for engine near applications require temperature stable materials to provide reliable electronics. The ambient temperatures reach up to 170 °C or more. Additional cost effective packaging solutions have to be chosen to achieve competitive products. For these requirements a new approach, based on a more detailed knowledge about thermo-mechanical behavior of the utilized materials is necessary. For organic substrate materials which are used for printed circuit boards (PCBs) the high operation temperatures are the limiting factors due to polymer property changes and degradation mechanisms. With this study a more precise characterization of these materials is done to open new fields of materials application and to benchmark the material limits. Therefore different thermal analysis methods like dynamic mechanical analysis (DMA) and thermal mechanical analysis (TMA) can be used. A description of the difficulties in measurement parameter selection and result interpreting is given. Subsequently measurement results for epoxy based substrate materials which were analyzed prior and after exposure to thermal stress are presented.