In this study, SiO2 nanoparticles were synthesized by an eco-friendly method, which excludes harmful elements, such as NO3-, and in so doing, lowers the heat-treatment temperature from 500 to 300 degrees C, leading to the downsizing of the nanoparticles. The sizes of the SiO2 nanoparticles were less than 20 nm and were uniformly distributed. In the XRD analysis, the most intense peak was observed at about 23.5 degrees confirming that the synthesized nanoparticles have a SiO2 structure. No harmful elements such as NO3- were found in the SiO2 nanoparticles, showing that their purity was improved. Also, SiO2 paste was well formulated by dispersing the SiO2 nanoparticles uniformly in a solvent uniformly. The SiO2 paste printed onto a glass substrate followed by curing at 200 degrees C showed good insulating and dielectric properties. The resistance and the dielectric constant of the printed layer were above 10(11)Omega and 4.434, respectively. Those values were sufficient for insulating and dielectric characteristics. Therefore, the SiO2 nanoparticles synthesized by this eco-friendly method have the potential to be used as the material for insulating and dielectric layers. (C) 2010 Elsevier B.V. All rights reserved.