Novel high temperature polymeric encapsulation material for extreme environment electronics packaging

Abstract

This study explores the usage of resorcinol based phthalonitrile (rPN) in harsh environment electronics encapsulation applications. rPN itself exhibits excellent properties as a high temperature polymeric molding compound in terms of mechanical properties and thermal stability. Its properties improve with thermal aging, outperforming other traditional polymers at operational temperatures close to 300 °C. Optimal bond shear strength of rPN is achieved when used as a monomer or pre-polymer with a low melting point of 180 °C, which is compatible with today's electronic packaging processes. The hybrid polymer of rPN with fillers, such as silica or alumina, has a coefficient of thermal expansion (CTE) which is highly tunable, allowing the rPN to have strong adhesion to the underlying substrates and chips. The properties of the rPN hybrid polymer is the result of strong bond interactions between rPN and the fillers, as verified by Fourier Transform Infrared Spectroscopy (FTIR) and Density Functional Theory (DFT) studies. We further demonstrate the integration of the rPN hybrid polymer onto dual-in-line packages (DIPs), which did not fail when subjected to an extreme environment of 310 °C at 190 MPa. This new polymer matrix composite may thus revolutionize the existing thermal-mechanical limits of plastic electronics packaging for extreme environment.