Separation of low molecular siloxanes for electronic application by liquid-liquid extraction [packaging materials

Abstract

Silicone resins are widely used for electronic packaging as potting and encapsulating materials. Silicone resins have many advantages for electronic packaging applications such as superior electrical properties, thermal stability, low water absorption, etc. Silicone resins are not only used as protective materials for IC devices but also as conducting materials for interconnection. However, silicone resins have two big drawbacks: low adhesion strength and low molecular weight creep. A simple liquid-liquid extraction method has been developed to purify silicone resins, which improves adhesion strength and eliminates low molecular weight creep. This paper describes the results of the liquid-liquid extraction method to remove low molecular weight cyclic siloxanes. Fourier transform-infrared (FTIR) spectroscopy was used to monitor the removal rate of low molecular weight cyclic siloxanes. Thermogravimetric analysis (TGA) was used to evaluate the purity of the silicone resin. Gas chromatography-mass spectrometry (GC-MS) was used to identify the low molecular weight cyclic siloxanes.