Search

CN-122025420-A - Multilayer ceramic capacitor and preparation method thereof

CN122025420ACN 122025420 ACN122025420 ACN 122025420ACN-122025420-A

Abstract

The application provides a multilayer ceramic capacitor and a preparation method thereof, belonging to the technical field of ceramic capacitors, wherein the method comprises the steps of dry-pressing and forming granulated ceramic powder in a square die to obtain a green body; the method comprises the steps of preparing a non-full electrode by using a green blank, drying, carrying out dislocation stacking on a dried green blank to form a multi-layer capacitor parallel structure, carrying out dislocation stacking to rotate electrode patterns of adjacent layers by a preset angle, carrying out vacuum packaging and cold isostatic pressing on a device formed by dislocation stacking, wherein the pressure of the cold isostatic pressing is smaller than that of dry press forming, sintering the device subjected to cold isostatic pressing in a reducing atmosphere, and carrying out end sealing on an exposed area of an electrode on the side surface of the device after sintering, and welding leads and packaging the upper surface and the lower surface of the device. By the processing scheme, the multilayer ceramic capacitor with high withstand voltage, small volume and high capacity is obtained, and the volume efficiency of the die pressing capacitor is improved while the withstand voltage is ensured.

Inventors

  • LIU YIQIAN
  • Liu Juanfu
  • SUN SHILUN

Assignees

  • 昆山清元电子科技有限公司

Dates

Publication Date
20260512
Application Date
20260320

Claims (10)

  1. 1. A method of manufacturing a multilayer ceramic capacitor, the method comprising: Dry-pressing the granulated ceramic powder in a square die to obtain a green body; Printing plasma material on the green body, preparing a non-full electrode, and drying; the dried green bodies are stacked in a staggered mode to form a multi-layer capacitor parallel structure, and the staggered stacking is that electrode patterns of adjacent layers rotate by a preset angle; vacuum packaging the device formed after staggered stacking, and performing cold isostatic pressing, wherein the pressure of the cold isostatic pressing is smaller than that of dry pressing; Sintering the device subjected to cold isostatic pressing in a reducing atmosphere; After sintering, the exposed area of the side electrode of the device is blocked, and the upper surface and the lower surface of the device are welded with leads and packaged.
  2. 2. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein the dry press forming pressure is 300MPa and the cold isostatic pressing pressure is 220MPa to 240MPa.
  3. 3. The method of manufacturing a multilayer ceramic capacitor according to claim 1, wherein the plasma material is Ni paste, and the Cu paste is used to terminate the exposed region of the device side electrode.
  4. 4. The method of manufacturing a multilayer ceramic capacitor according to claim 1, wherein the green sheet is printed with a plasma material to manufacture a non-full electrode, comprising: Reserving blank with preset width on two adjacent edges of the green embryo, and printing plasma materials to prepare the non-full electrode.
  5. 5. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein the sintering temperature is 1100 ℃ to 1300 ℃ and the holding time is 3 hours.
  6. 6. The method for manufacturing a multilayer ceramic capacitor according to claim 1, wherein the side length a of the square mold is 10mm or less, and the thickness t of the square mold is calculated as: , the calculation formula of the number of staggered stacked layers is as follows: , wherein, C is a capacitor, The absolute dielectric constant and n is the number of layers.
  7. 7. A method of manufacturing a multilayer ceramic capacitor, the method comprising: preparing ceramic slurry, wherein the ceramic slurry contains a gas phase SiO 2 thixotropic agent and an ammonium polyacrylate dispersing agent; Using an alumina ceramic plate as a substrate, using a high-precision screen printer to alternately print a ceramic layer and an electrode layer by using ceramic slurry and Ni slurry, wherein the electrodes are not full electrodes and are stacked in a staggered manner to form a multi-layer capacitor parallel structure, and the staggered stacking is that electrode patterns of adjacent layers are rotated by a preset angle; solidifying the device formed after staggered stacking; sintering the cured device in a reducing atmosphere; After sintering, the exposed area of the side electrode of the device is blocked, and the upper surface and the lower surface of the device are welded with leads and packaged.
  8. 8. The method of manufacturing a multilayer ceramic capacitor according to claim 7, wherein the alternately printed ceramic layers and electrode layers, wherein the electrodes are not fully filled electrodes, are stacked in a staggered manner, comprising: carrying out hot-pressing compounding after alternately printing the ceramic layers and the electrode layers to 5 layers, wherein the temperature of hot-pressing compounding is set to 65-75 ℃; and repeatedly stacking until the target layer number is reached after hot-pressing compounding, wherein the electrode is not a full electrode, and stacking in a staggered way.
  9. 9. The method for producing a multilayer ceramic capacitor according to claim 7, further comprising subjecting the alumina ceramic plate to a surface pretreatment including plasma cleaning and applying a temporary release layer.
  10. 10. A multilayer ceramic capacitor, characterized in that the multilayer ceramic capacitor is prepared by the preparation method of any one of claims 1 to 6 or the preparation method of any one of claims 7 to 9, and the electrodes in the multilayer ceramic capacitor are non-full electrodes and are stacked in a staggered manner.

Description

Multilayer ceramic capacitor and preparation method thereof Technical Field The application relates to the technical field of ceramic capacitors, in particular to a multilayer ceramic capacitor and a preparation method thereof. Background With the development of new energy automobile fast charging systems, smart grid devices and industrial frequency converters, the demands for high-voltage-resistant, high-capacity and small-volume ceramic capacitors are rapidly increasing. The capacitor needs to meet the requirements of insulation reliability, volume efficiency, high capacity value in a limited space, and high-frequency characteristic, low ESR (equivalent series resistance) and energy transmission efficiency. The main flow technical route at present has the contradiction that the wafer capacitor based on the mould pressing technology has higher voltage resistance value due to thicker layer thickness, but smaller capacity, and the parallel capacitor is limited by epoxy resin encapsulation and has larger volume. Therefore, no proper technical scheme is available in the prior art to ensure that the ceramic capacitor has three performance indexes of high withstand voltage, large capacity and small volume. Disclosure of Invention In view of the above, embodiments of the present application provide a multilayer ceramic capacitor and a method for manufacturing the same, which can increase the capacity of the ceramic capacitor under the premise of high withstand voltage and small volume. In a first aspect, an embodiment of the present application provides a method for manufacturing a multilayer ceramic capacitor, the method including: Dry-pressing the granulated ceramic powder in a square die to obtain a green body; Printing plasma material on the green body, preparing a non-full electrode, and drying; the dried green bodies are stacked in a staggered mode to form a multi-layer capacitor parallel structure, and the staggered stacking is that electrode patterns of adjacent layers rotate by a preset angle; vacuum packaging the device formed after staggered stacking, and performing cold isostatic pressing, wherein the pressure of the cold isostatic pressing is smaller than that of dry pressing; Sintering the device subjected to cold isostatic pressing in a reducing atmosphere; After sintering, the exposed area of the side electrode of the device is blocked, and the upper surface and the lower surface of the device are welded with leads and packaged. According to a specific implementation of the embodiment of the application, the dry press forming pressure is 300MPa, and the cold isostatic pressing pressure is 220-240 MPa. According to one specific implementation of the embodiment of the application, the plasma material is set to be Ni slurry, and Cu slurry is adopted to end-cap the exposed area of the side electrode of the device. According to a specific implementation manner of the embodiment of the application, the preparation of the non-full electrode by the green body printing plasma material comprises the following steps: Reserving blank with preset width on two adjacent edges of the green embryo, and printing plasma materials to prepare the non-full electrode. According to a specific implementation of the embodiment of the application, the sintering temperature is 1100-1300 ℃ and the heat preservation time is 3 hours. According to a specific implementation manner of the embodiment of the application, the side length a of the square mold is less than or equal to 10mm, and the calculation formula of the thickness t of the square mold is as follows: , the calculation formula of the number of staggered stacked layers is as follows: , wherein, C is a capacitor, The absolute dielectric constant and n is the number of layers. In a second aspect, an embodiment of the present application further provides a method for manufacturing a multilayer ceramic capacitor, the method including: preparing ceramic slurry, wherein the ceramic slurry contains a gas phase SiO 2 thixotropic agent and an ammonium polyacrylate dispersing agent; Using an alumina ceramic plate as a substrate, using a high-precision screen printer to alternately print a ceramic layer and an electrode layer by using ceramic slurry and Ni slurry, wherein the electrodes are not full electrodes and are stacked in a staggered manner to form a multi-layer capacitor parallel structure, and the staggered stacking is that electrode patterns of adjacent layers are rotated by a preset angle; solidifying the device formed after staggered stacking; sintering the cured device in a reducing atmosphere; After sintering, the exposed area of the side electrode of the device is blocked, and the upper surface and the lower surface of the device are welded with leads and packaged. According to a specific implementation manner of the embodiment of the present application, the alternately printing ceramic layers and electrode layers, wherein the electrodes are not full electrodes,