Electronic ceramics refer to ceramics that can utilize electrical and magnetic properties in the electronics industry. Electronic ceramics are obtained through precise control of surface, grain boundaries, and dimensional structure, ultimately resulting in ceramics with new functions. They possess characteristics such as good high-frequency performance, a wide adjustable range of dielectric constant, low dielectric loss, adjustable temperature coefficient, good density, and diverse properties.
Electronic ceramic materials can be classified into five categories according to their function and application: insulating ceramics, capacitor ceramics, ferroelectric ceramics, semiconductor ceramics, and ion ceramics.
Insulating ceramics are functional ceramics with excellent insulation and mechanical properties, also known as device ceramics. Their core characteristics include low dielectric loss, high resistivity, high thermal conductivity, and stable physicochemical properties, allowing them to withstand extreme environments such as high temperatures and high frequencies. Typical materials include alumina ceramics and talc ceramics. Alumina ceramics enhance insulation by increasing the Al2O3 content (75%-99.9%), with 99.9% pure corundum ceramics exhibiting properties approaching those of sapphire single crystal. Alumina ceramics possess high mechanical strength, high volume resistivity, good electrical insulation properties, high strength, wear resistance, and oxidation resistance. Talc ceramics, primarily composed of MgSiO3, possess both low dielectric loss and high mechanical strength, making them suitable for radio frequency (RF) bands.
With increasing heat dissipation demands in the electronics industry, beryllium oxide ceramics have been developed due to their thermal conductivity, which is close to that of metallic aluminum. However, their use is limited by the toxicity of the raw materials. Aluminum nitride ceramics, due to their non-toxicity and good processing properties, are gradually becoming the preferred heat dissipation material for high-frequency, high-power devices. The most significant characteristic of beryllium oxide ceramics is their high thermal conductivity, approaching that of metallic aluminum, along with good dielectric properties. They are excellent materials for manufacturing high-power transistor housings, heat sinks, high-power integrated circuits, and microwave integrated circuit substrates. However, the toxicity of beryllium oxide raw materials and the high firing temperature of the ceramic limit its applications. Boron nitride and aluminum nitride ceramics also belong to the category of high thermal conductivity ceramics. While their thermal conductivity is not as high as that of beryllium oxide ceramics, they are non-toxic, have good processing and dielectric properties, and can be used for heat dissipation and insulation in high-frequency, high-power transistors and hybrid integrated circuits.
