Nickel electrode MLCs

Further miniaturization of chip capacitors with thinning the dielectric layer and electrode laydown is also effective for the production cost. By incorporating thinner dielectric layers with nickel compatible dielectrics and nickel electrode, large capacitance MLCs comparable to tantalum electrolytic capacitors have been developed. To reduce the dielectric thickness less than few micrometers, further development of ultrafine grain BaTiOs is indispensable. 

A ceramic chip capacitor of 100 p.F was developed with nickel electrode system to meet the condition of decoupling capacitors for VLSI and switching mode power supply. The fundamental characteristics of the newly developed X5R 100 xF MLC are shown in Table 5.1.3. A large volumetric efficiency... 

Since dramatic increase of palladium price during 1995 to 1997, the MLC manufactures had extreme pressure to reduce the electrode cost, and so accelerated the expansion of MLCs production with base metal electrode such as nickel and copper to substitute the palladium. Nickel metal is easily oxidized in air at elevated temperature. Therefore, the capacitor with nickel and copper inner electrode must be fired in a low oxygen pressure atmosphere. Conventional ceramics, however, have poor insulation resistance after heat treatment in such reducing atmosphere. 

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