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 punfy silicone resins, which will improve adhesion strength and eliminate 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 (FT-IR) spectroscopy was used to monitor the removal rate of low molecular weight cyclic siloxanes. Thermogravimetric analysis (TGA) was used to evaluate the purity of silicone resin. Gas chromatography-mass spectrometry (GC-MS) was used to identlfy the low molecular weight cyclic siloxanes. 10. Kazunari Suzuki, Tomoko Higashino, Kunihiro Tsubosaki, Akira Kabashima, Katsutoshi Mine, Kazumi Nakayoshi, ('Development of low elastic modulus die attach material and clean cure process", Bm. of 40th IEEE Elec. Components and &hology G.zz&rence, p. 835-839, (1990).