Influence of Alumina Contents and Firing Temperature on the Electrical Properties of Alumina Substrates

We studied the effects of alumina content and firing temperature on the electrical properties of alumina substrate. Alumina content was varied within the range 91.5% to 98.8%, and firing temperature, within the range 1, 480°C to 1, 640°C. The higher the firing temperature, the greater become the volume resistivity, Te value, dielectric constant (e), and dielectric loss tangent (tan δ). When the alumina content is increased, the coefficient of electric loss (e×tan δ) which is a representative parameter of substrate properties of high frequency decreases, while the volume resistivity, a representative parameter of substrate insulated properties, and the Te value remain invariable.