Study On Dielectric Properties And Optical Basicity Of Aluminoborosilicate Glasses

Fiberglass is the essential reinforced material in present society. The printed circuit board(PCB) and radome are the main application field of fiberglass in the electronic. Presently electronic technology is developing to the miniaturization, the high density, the high performance and the multi-purpose. Related materials not only has high heat conductivity, high intensity but also must have the low dielectric constant (εr) and low dielectric loss (tanδ) which can reduce RC delay time and speed up the signal transmission. Thus, the study of low dielectric glass material is imperative.Al₂O₃-B₂O₃-SiO₂ glass system as a low dielectric glass-fiber-based system, has been obtain extensive attention from scholars at home and abroad. We choose the original E-glass system for the based system. The influence of SiO₂, B₂O₃ and Al₂O₃ contents on properties of glass was discussed in the paper. The level of selection factors based on pre-test and information is SiO₂: 51.5%, 53.5% and 55.5%; Al₂O₃: 12.5%, 14.5% and 15.5%; CaO: 4.0%, 7.0% and 10.0%. This is an orthogonal test with three factors and three levels. Through analysis, we obtained the optimal ratio which is SiO₂: 53.5%, Al₂O₃: 14.5%; CaO: 4.0%. Namely, the ratio of the glass has a low dielectric constant and low dielectric loss, and the melting situation is better.Regression analysis is another statistical tool, which is useful in quantitative description of complex relationships between experimental factors and results. It can also be used to predict unknown experimental results with high precision. In the current work, linear regression analysis was performed to reveal the dependence of dielectric properties on experimental factors. After being optimized, the regression equation was utilized to predict experimental results. The precision and applicability of prediction was discussed at the same time. In this paper, according to the linear regression theory, we fitted out the linear regression equation using 49 sets of date which has described the relationship between the dielectric constant and optical basicity. Unary linear regression analysis showed that the linear relationship exists between the glass theoretical optical basicity values and dielectric constant, and its correlation coefficient is 0.9245. With magnesium oxide substitute calcium oxide,the dielectric constant was predicted after the changes of glass composition using the regression equation. The experimental result was nearly same to estimated result. That proved the correctness of the equation. Then, the regular of the variation of dielectric constant with changes of composition was explicated from the perspective of optical basicity. Optical basicity value is useful to design the composition of low dielectric constant glass fiber.The dielectric properties were investigated using infrared spectroscopy, differential thermal analysis and other testing methods after a part of boron oxide was replaced by calcium oxide. Draw the following conclusions: the relative dielectric constant of glass decreases with increasing of titanium dioxide content. Infrared spectra indicate that borate group combined priority with the alkaline-earth metal oxides when the content of CaO in glass was more. According to the principle of avoiding tetrahedron, more and more borate group link to the silicate structural unit when the content of calcium oxide was less. Differential thermal analysis showed that the glass transition temperature (Tg) gradually increased with the increase of the amount of titanium dioxide.