Material characterization of fluorosilicone gels for automotive application

Fluorosilicone gel is commonly used in die passivation. This paper studies the characteristics of fluorosilicone gel applied on the manifold air pressure (MAP) sensor die. The cure mechanism and material characterization of the three types of gels were analyzed using differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), and rheometer. The temperature and time relationships were derived for each material type. In the process of characterization, it was discovered that characterized material does not always behave as expected in the production confirmation run. It was found that the gel selected interacted with the thermoplastic packaging material hence leading to further findings of cure inhibitation. This paper concludes with the valuable lessons learnt from this material characterization project and explains the importance of these lessons learnt to actual manufacturing experience.