Production of ceramic substrates via tape casting for high-frequency multifunctional applications.
Tape casting, dielectric properties, high-frequency substrates, ceramic materials
Technological development is driving some researches on new dielectric substrates, crucial for the advancement and efficiency of high-frequency electronic devices. The increasing demand for quick, small devices with high storage capacity has led to the development of materials with superior dielectric properties able of withstanding higher electrical stresses and offering better insulation. Among the various approaches to produce these materials, tape casting stands out as a highly popular method for manufacturing homogeneous, flexible ceramic films with controlled thickness, large surface area, and low cost. The aim of this work is to develop multifunctional ceramic dielectric tapes, Al2O3-hBN and diatomite-graphene, using the tape casting technique for high-frequency applications. The results showed that a 463% increase in the dielectric constant compared to the green alumina tape and the green tape incorporated with 10% by weight of hBN. For samples sintered at 1600 °C, an increase of 42.16% in the dielectric constant was observed, with low loss factor. The diatomite-graphene tape showed approximately 100% in the increasing of the dielectric constant with the addition of 10% by weight of graphene. Capacitance showed better results at a frequency of 120 Hz leading to 6.72 nF for the incorporation of 10 wt.% of graphene, representing an increase of 215% compared to pure diatomite capacitance. Furthermore, due to the excellent stability of the dielectric constant over a wide frequency range (0.1 to 1.5 GHz), graphene doped diatomite and hBN-doped alumina substrates demonstrate potential applicability as high-frequency substrates in electronic transmission devices.