Small Y5V chip-capacitors with very large capacitance

A multilayer ceramic capacitor with high specific capacitance was fabricated using 15-μ-thick green sheets. The composition of the dielectric material used was Pb(Mg_1/3Nb_2/3)_0.2(Ni_1/3 Nb _2/3)_0.6Ti_0.2O₃ (ε=20000 at 20°C). The single-layer thickness of the dielectric material was 11 μm after sintering. This capacitor has 50% of the volume of a tantalum electrolytic capacitor with the same capacitance. The temperature variation of the capacitance meets Y5V specifications. The frequency-dependences of the capacitance, dissipation factor, and impedance were better than those of the tantalum electrolytic capacitor. In accelerated load-life tests (125°C, 50 V) and the load-humidity tests (85°C, 90 to 95% RH, 25 V), no degradation of the insulation resistance was found during 1000 hours of testing. A multilayer ceramic capacitor with 10-μF capacitance was also fabricated using 10-μm-thickness green sheets. The dimensions of the capacitor were (3.2×2.5×1.5) mm³ and the (postsintering) single-layer thickness of the dielectric ceramic was 6 μm