Chemical coating prepared base metal internal electrode multi-layer ceramic chip capacitor dielectric material

Abstract

The invention discloses a chemical coating prepared dielectric material of base-metal electrode multilayer ceramic capacitor, belonging to the capacitor material preparing technology, which adopts the technical proposal that a plurality of barium titanate grains are coated by the doped elements through chemical coprecipitation; the main ingredient, barium titanate BaTiO3, accounts for 90mol% to 97mol% of the prescription; the amount of nanometer inhibitory coating composite oxide accounts for 3mol% to 10mol% of the total materials. The ceramic material is sintered at a reducing atmosphere controlled by a humidified gas mixture of nitrogen and hydrogen at a temperature between 950 to 1250 DEG C to get a X7R / X5R type MLCC material; wherein the dielectric constant of the material at room temperature is 2000 to 2700; the temperature coefficient of capacitance is less than or equal to positive and negative 15%; the dielectric loss at room temperature is less than or equal to 2%. The ceramic crystal grain under 200nm has low dielectric loss and good material uniformity; the multilayer ceramic capacitor produced with the ceramic crystal grain has the advantages of large capacity, ultrathin dielectric layer and the thickness less than 2um.

Description

technical field [0001] The invention belongs to the technical field of electronic ceramic capacitor materials, in particular to a dielectric material for multilayer ceramic chip capacitors prepared by chemical coating for inner electrodes of base metals. Specifically, it relates to the production of a base metal internal electrode multilayer ceramic chip capacitor dielectric material with ultra-fine crystal temperature stable base metal internal electrodes using a chemical coating method as the internal electrode. Background technique [0002] Multilayer Ceramic Capacitors (MLCC) for short. It alternately stacks the ceramic green body and internal electrodes, and co-fires them as a whole. MLCC is especially suitable for chip surface assembly, which can greatly increase the density of circuit assembly and reduce the volume of the whole machine. This outstanding feature makes MLCC the largest and fastest growing chip component in the world. According to the EIA (Electronic I...

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Problems solved by technology

However, the reduction of the grain size often leads to the reduction of the dielectric constant. In US-62709906B1, when the ceramic grain size is reduced to 100-200 nanometers, the dielectric constant is 1600-1800, which are all lower than 2000.

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