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CN-121983443-A - Preparation method of ceramic silver electrode and ceramic capacitor

CN121983443ACN 121983443 ACN121983443 ACN 121983443ACN-121983443-A

Abstract

The invention belongs to the technical field of ceramic capacitors, and discloses a preparation method of a ceramic silver electrode, which comprises the following steps of mixing silver ammonia solution and glucose solution, spraying the mixture on a ceramic base surface, forming an arched surface by the mixed solution under the action of surface tension, forming a solution coacervate with decreasing stacking quantity from the center to the periphery, heating the solution coacervate for 10-30min under the condition of 25-60 ℃ in a protective gas atmosphere to primarily dry the solution coacervate, controlling the heating rate to be in the range of 1-2 ℃ per min in the heating process, then heating to 150-200 ℃ at the rate of 2-5 ℃ per min, preserving heat for 10-60min, enabling the primarily dried solution coacervate to further react to form a densified silver layer, and then cooling to room temperature at the rate of less than or equal to 3 ℃ per min to obtain the silver electrode. Compared with the screen printing or PVD processing mode, the electrode preparation method is lower in cost and improves the breakdown strength of the electrode center area. The invention correspondingly discloses a ceramic capacitor which comprises the silver electrode manufactured by the method.

Inventors

  • Liu Juanfu
  • YANG CONGMING
  • SUN SHILUN
  • LIU YIQIAN

Assignees

  • 昆山清元电子科技有限公司

Dates

Publication Date
20260505
Application Date
20260205

Claims (10)

  1. 1. The preparation method of the ceramic silver electrode is characterized by comprising the following steps of: Firstly, mixing silver ammonia solution and glucose solution, spraying the mixture on a ceramic base surface (2), forming an arched cambered surface by the mixed solution under the action of surface tension, forming a solution coacervate (3) with decreasing stacking quantity from the center to the periphery, and then heating the solution coacervate (3) for 10-30min at 25-60 ℃ in a protective gas atmosphere to primarily dry the solution coacervate (3), wherein the heating rate is controlled within the range of 1-2 ℃ per min in the heating process; Step two, heating to 150-200 ℃ at the speed of 2-5 ℃ per min, and preserving heat for 10-60min to further react the primarily dried solution coacervate (3) to form a densified silver layer; and thirdly, cooling to room temperature at a rate of less than or equal to 3 ℃ per minute to obtain the silver electrode with the thickness gradually decreasing from the center to the edge and the surface smoothly transiting.
  2. 2. The method for preparing the ceramic silver electrode according to claim 1, wherein in the first step, silver ammonia solution and glucose solution are mixed by means of a spray head (1) and then sprayed on a ceramic base surface (2), the spray head (1) comprises a plurality of spray holes (131), and the distribution density of the spray holes (131) is gradually decreased from the center to the periphery to form a plurality of annular distributing belts.
  3. 3. The method of manufacturing a ceramic silver electrode according to claim 2, wherein the density of the nozzle holes (131) of the plurality of annular distribution strips is gradually decreased from the inner ring to the outer ring.
  4. 4. The method for preparing a ceramic silver electrode according to claim 2, wherein the annular distributing belt is in a circular ring shape or a regular polygon ring shape.
  5. 5. The method for preparing a ceramic silver electrode according to any one of claims 2 to 4, wherein the pore diameter of the spray holes (131) is in the range of 0.2 to 0.5mm, and the pore diameters of the plurality of spray holes (131) are the same or are in a decreasing state from the inner ring to the outer ring.
  6. 6. The method of manufacturing a ceramic silver electrode according to claim 1, wherein in the first step, the concentration of the silver-ammonia solution is 5 to 10% (w/v), the concentration of the glucose solution is 10 to 20% (w/v), and the volume ratio of the two solutions is1 (1-2).
  7. 7. The method of manufacturing a ceramic silver electrode according to claim 6, wherein after the completion of the first step, the first step is repeated twice, and the second step is performed, and wherein the maximum thickness of the solution coacervate (3) after each spraying is controlled to be 1-2. Mu.m.
  8. 8. The method of manufacturing a ceramic silver electrode according to claim 7, wherein the concentration of the silver-ammonia solution sprayed for the first time is 5-6.5% (w/v), the concentration of the silver-ammonia solution sprayed for the second time is 6.5-8.5% (w/v), and the concentration of the silver-ammonia solution sprayed for the third time is 8.5-10% (w/v).
  9. 9. The method of claim 1, wherein in the first step, the preliminary drying temperature is 40-60 ℃.
  10. 10. A ceramic capacitor comprising a silver electrode, wherein the silver electrode is prepared by the method of any one of claims 1-9.

Description

Preparation method of ceramic silver electrode and ceramic capacitor Technical Field The invention belongs to the technical field of ceramic capacitors, and particularly relates to a preparation method of a ceramic silver electrode and a ceramic capacitor. Background The ceramic capacitor is usually prepared by printing or PVD sputtering. Printing or PVD sputtering and other modes have low printing efficiency, slurry easily overflows the electrode surface, PVD equipment has high price and higher investment in the early stage, and the bonding force of the PVD sputtered electrode and ceramic has higher requirements on the cleanliness and the surface roughness of the ceramic surface. Based on defect research of the existing product, the electrode prepared by the traditional printing or PVD sputtering and other modes is a planar electrode, but the electrified position is the center point of the capacitor, so that the common breakdown position of the planar electrode is the center point, if the breakdown strength of the electrode part needs to be improved, the thickness of the center point needs to be improved, and the electrode prepared by the traditional printing or PVD sputtering and other modes is the planar electrode, so that the center thickness and the edge thickness cannot be achieved, and the overall thickness is greatly increased. In order to solve the foregoing problems, CN104319095A in the related art discloses a metallized film for a capacitor and a manufacturing process thereof, in which materials such as silver, aluminum, zinc, etc. are plated on a base film by vacuum evaporation to obtain a metallized film for a capacitor including a plurality of plating units with varying thickness, which improves the performance of the capacitor, but such a process is complicated and is not suitable for plating a metal material on a ceramic base layer. Disclosure of Invention The invention aims to provide a preparation method of a ceramic silver electrode and a ceramic capacitor, which are simple in process and low in cost. In a first aspect, the invention provides a preparation method of a ceramic silver electrode, which comprises the following steps: the preparation method of the ceramic silver electrode comprises the following steps: Firstly, mixing silver ammonia solution and glucose solution, spraying the mixture on a ceramic base surface, forming an arched surface by the mixed solution under the action of surface tension, and forming a solution coacervate with decreasing stacking amount from the center to the periphery, and then heating the solution coacervate for 10-30min under the condition of 25-60 ℃ in a protective gas atmosphere to primarily dry the solution coacervate, wherein the heating rate is controlled within the range of 1-2 ℃ per min in the heating process; Step two, heating to 150-200 ℃ at the speed of 2-5 ℃ per min, and preserving heat for 10-60min to further react the primarily dried solution coacervate to form a densified silver layer; and thirdly, cooling to room temperature at a rate of less than or equal to 3 ℃ per minute to obtain the silver electrode with the thickness gradually decreasing from the center to the edge and the surface smoothly transiting. Based on the scheme, the silver ammonia solution glucose mixed solution is coated in a spraying mode, the solution coacervate with thick middle and thin edges is formed by utilizing the liquid to represent tension, and the silver ammonia solution of the solution coacervate is reacted to form the silver electrode with gradually thinner thickness from the middle to the edges by matching with the control of the temperature rising rate and the heating temperature in the primary drying and heat treatment steps and removing most of water in the primary drying and post heat treatment to form the densified silver layer. Because the electrode energizing position is concentrated at the center point, the center breakdown voltage is improved compared with the printing or PVD processing mode under the same silver consumption by increasing the thickness of the silver layer in the center region (edge thinning). In the first step, silver-ammonia solution is sprayed on a ceramic base surface by means of a spray head, wherein the spray head comprises a plurality of spray holes, and the distribution density of the spray holes is gradually decreased from the center to the periphery to form a plurality of annular distributing strips. Such spray heads facilitate the formation of solution coacervates with decreasing amounts of solution stacking from the center to the periphery. Further, the density of the spray holes of the annular distributing belt is gradually decreased from the inner ring to the outer ring. Further, the annular distributing belt is in a circular ring shape or a regular polygon ring shape. Further, the aperture of the spray holes is in the range of 0.2-0.5mm, and the apertures of a plurality of spray holes are the same or are in a decreas