Fabrication and properties of alumino-borosilicate glass-ceramic systems

Abstract

In current microelectronics packaging applications, low-temperature fired substrates with low dielectric constant are required. Formulations of SiO₂, B₂O₃, Al₂O₃, and CaO have been used as substrate materials which can be sintered as low as 1000‡C in air. The electrical behaviour, thermal expansion coefficient, and mechanical property of the fabricated substrate materials are evaluated. The as-sintered substrates possess the following characteristics: low dielectric constant of 4–5 at 1 MHz; a loss factor smaller than 0.2% at 1 MHz; and a thermal expansion of 3.57 × 10⁻⁶‡C⁻¹ which is very close to that of silicon (3.5 × 10⁻⁶‡C⁻¹).