A Study on the Fabrication Parameters and Dielectric Properties of PTFE Composites Filled with Al 2 O 3 and SiO 2 Nanoparticles

Abstract

In order to fabricate and enhance the composites with dielectric functions, printed circuit boards (PCBs) were made from polytetrafluoroethylene (PTFE) gel after curing with 350°C. SiO₂ and Al₂O₃ nanopowders were used as the fillers and PTFE was the matrix used to fabricate the composites. A proposed stirring machine was used to conduct the compounding process, which can assist in the uniform distribution of nano-Al₂O₃ and nano-SiO₂ powders in PTFE. The PTFE gel was mixed in the proposed stirring machine. Following stirring, molding and calendaring were done to release air bubbles and to increase the surface uniformity and smoothness of PCBs. Finally, PCBs were fabricated after cooling and sintering processes. Several kinds of PCBs were made by varying a wide range of fabrication parameters which included: percentage of particles added, size of particles added, different fabrication procedures, rotational speeds of the stirring machine, sintering, and cooling temperature, and calendaring times. Influences of these parameters and fabrication conditions on the dielectric properties of PCBs were investigated. This study established that there are some fabrication parameters due to which we get the worst dielectric properties of PCBs. Therefore, the optimum fabrication conditions and affecting factors of the board were investigated. As a result of this research, it was concluded that both dielectric constant and loss factor of the board were decreased by the addition of SiO₂ and Al₂O₃ nanoparticles and the optimum rotational speed of stirring machine is 3000 rpm. Dielectric properties of PCBs were increased at speeds above 3000 rpm.

Keywords

polytetrafluoroethylene printed circuit boards SiO2 nanoparticle Al2O3 nanoparticle dielectric constant dielectric loss factor.

References

Daigle, B. ( 1996). Printed circuit board material and design considerations for wireless applications, In: Electronic Components and Technology Conference, Orlando, FL, 28-31 May, pp. 354-357.

Ming, C.C. ( 1998). Chemical Produce of PCB Topic Investigation Report, ROC , pp. 2.9-2.13.

Feng, C.F. and Froyen, L. ( 2000). Formation of Al3Ti and Al2O3 from an AlTiO2 System for Preparing In-situ Aluminium Matrix Composites, Composites Part A: Applied Science and Manufacturing, 31: 385-390.

Arthur, D.J. , Swei, G.S. , Horn, A.F. and Kilhenny, B. ( 1994). Low Volume Fraction Ceramic Filled Fluoropolymeric Composite Material, US Patent No. 5281466.

Arthur, D.J. , Swei, G.S. , Horn, A.F. and Kilhenny, B. ( 1995). Low Volume Fraction Ceramic Filled Fluoropolymeric Composite Material, US Patent No. 5384181.

Rajesh, S. , Murali, K.P. , Priyadarsini, V. , Potty, S.N. and Ratheesh, R. ( 2009). Rutile Filled PTFE Composites for Flexible Microwave Substrate Applications, Materials Science and Engineering B, 163: 1-7.

Xiang, F. , Wang, H. and Yao, X. ( 2006). Preparation and Dielectric Properties of Bismuth Based Dielectric/PTFE Microwave Composites, Journal of the European Ceramic Society, 26: 1999-2002.

Murali, K.P. , Rajesh, S. , Om Prakash , Kulkarni, A.R. and Ratheesh, R. (2009). Preparation and Properties of Silica Filled PTFE Flexible Laminates for Microwave Circuit Applications , Composites Part A: Applied Science and Manufacturing, 40(8): 1179-1185.

Machetta, P. , Lazzarino, M. , Carrato , S. , Schmidt, C. , Canil, G. , Kapeliouchko, V. , Poggio, T. and Sanguineti, A. (2003). PTFE Nanoemulsions as Ultralow-k Dielectric Materials, Materials Science in Semiconductor Processing, 5: 285-290.

10.

Wang, J. , Kim, H.K. , Shi, F.G. , Zhao, B. and Nieh, T.G. ( 2000). Thickness Dependence of Morphology and Mechanical Properties of on-Wafer Low-k PTFE Dielectric Films, Thin Solid Films , 377-378: 413-417.

11.

Chen, L.M. , Zhang, J. , Teng, H. , Dong, Q.L. , Chen, Z.L. , Liang, T.J. , Zhao, L.Z. and Wei, Z.Y. ( 2001) Experimental Study of a Subpicosecond Pulse Laser Interacting with Metallic and Dielectric Targets, Physical Review E, 63(3): Art No. 036403, Part 2.

12.

Özkirim, İ. and Yörükoğullari , E. Characterisation of Bet Isotherm from Manisagördes Natural Zeolite (Clinoptilolite), Aralik (2005), Sayi:9, pp. 65-70.

13.

Tsai, I.S. and Kuo, Y.C. ( 2004). Dielectric Properties of the PCB of Polytetrafluoroethylene/SiO2 Nanoparticle, In: International Congress of Nanotechnology (ICNT), San Francisco, USA, 7-11 November.