Grain Boundary Layer Cermaic Single Layer chip Capacitor for Microwave Circuit

The relationship of the composition and properties of donor doping SrTiO₃ semiconductor ceramic that sintered in the reducing atmosphere were studied. Through equivalent circuit analysis and XRD, SEM, we discussed the mechanism that grain boundaries effect and characteristics affected ceramic performance, which made the dielectric constant of grain boundary layer ceramic substrate for single layer chip capacitor are adjustable (10000~50000), and the capacitance change rate was low(lesplusmn4.7%~lesplusmn22%), and the adaptable temperature range was wide (-55degC~+125degC). By sputtering and electroplating, the ceramic substrates were plated electrode. By photolithography, corrosion and precision machining , the substrates with electrode were manufactured into general single layer chip capacitor, surface mounted single layer chip capacitor, multi-pad single layer chip capacitor and single layer chip capacitor array for microwave circuit.