Method for manufacturing multilayer ceramic electronic element

Abstract

A method for manufacturing a multilayer ceramic electronic element includes the steps of forming ceramic green sheets having superior surface smoothness and small variations in thickness at a high speed, in which defects such as pinholes are prevented from occurring, and providing internal electrodes and step-smoothing ceramic paste on the ceramic green sheets with high accuracy. The method includes the steps of applying ceramic slurry to a base film by a die coater followed by drying performed in a drying furnace for forming the ceramic green sheets, and performing gravure printing of conductive paste and ceramic paste onto the ceramic green sheets by using a first and a second gravure printing apparatus, respectively. Accordingly, the internal electrodes are formed, and the step-smoothing ceramic paste is provided in regions other than those in which the internal electrodes are formed.

What is claimed is:  
     
         1 . A method for manufacturing a multilayer ceramic electronic element, comprising the steps of: 
 applying ceramic slurry to a base film using a die coater for forming ceramic green sheets;    applying conductive paste to upper surfaces of the ceramic green sheets by gravure printing for forming internal electrodes;    printing step-smoothing ceramic paste onto the upper surfaces of the ceramic green sheets in regions other than those in which the internal electrodes are formed;    laminating the ceramic green sheets having the internal electrodes and the step-smoothing ceramic paste to each other with at least one ceramic green sheet having neither the internal electrodes nor the step-smoothing ceramic paste for forming a laminate body;    firing the laminate body for forming a sintered body; and    forming external electrodes on external surfaces of the sintered body so as to be electrically connected to the internal electrodes.    
     
     
         2 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , further comprising a step of drying or partially drying the internal electrodes continuously after the step of applying conductive paste.  
     
     
         3 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , further comprising a step of drying the step-smoothing ceramic paste right after the printing step.  
     
     
         4 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , wherein the base film is a long base film, and the forming step is performed while the long base film is conveyed in a length direction thereof.  
     
     
         5 . A method for manufacturing a multilayer ceramic electronic element according to  claim 4 , wherein the applying step and the printing step are continuously performed while the ceramic green sheets provided on the long base film are conveyed in the length direction thereof.  
     
     
         6 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , wherein the printing step is performed after the applying step.  
     
     
         7 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , wherein the applying step is performed after the printing step.  
     
     
         8 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , wherein the ceramic green sheets and the step-smoothing ceramic paste primarily form a dielectric ceramic used for a multilayer ceramic capacitor as the multilayer ceramic electronic element.  
     
     
         9 . A method for manufacturing a multilayer ceramic electronic element according to  claim 1 , wherein the laminating step includes forming second ceramic green sheets on the respective ceramic green sheets having the internal electrodes and the step-smoothing ceramic paste for forming three-layered intermediate laminates, and then bonding the intermediate laminates to each other by compression for forming the laminate.  
     
     
         10 . A method for manufacturing a multilayer ceramic electronic element according to  claim 9 , wherein the step-smoothing ceramic paste and the second ceramic green sheets are simultaneously provided so as to obtain the intermediate laminate bodies.  
     
     
         11 . A method for manufacturing a multilayer ceramic electronic element, comprising the steps of: 
 applying ceramic slurry to a base film using a die coater for forming ceramic green sheets;    applying conductive paste to upper surfaces of the ceramic green sheets by gravure printing for forming internal electrodes;    allowing the ceramic green sheets to pass through between a gravure roller and a pressure roller so as to print step-smoothing ceramic paste onto the upper surfaces of the ceramic green sheets in regions other than those in which the internal electrodes are formed and simultaneously to compress the internal electrodes by the gravure roller for planarization;    laminating the ceramic greens sheets having the internal electrodes and the step-smoothing ceramic paste to each other with at least one ceramic green sheet having neither the internal electrodes nor the step-smoothing ceramic paste for forming a laminate;    firing the laminate for forming a sintered body; and    forming external electrodes on external surfaces of the sintered laminate so as to be electrically connected to the internal electrodes.    
     
     
         12 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , further comprising a step of drying or partially drying the internal electrodes continuously after the step of applying conductive paste.  
     
     
         13 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , further comprising a step of drying the step-smoothing ceramic paste right after the step-smoothing paste is printed onto the upper surfaces of the ceramic green sheets.  
     
     
         14 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , wherein the base film is a long base film, and the forming step is performed while the long base film is conveyed in a length direction thereof.  
     
     
         15 . A method for manufacturing a multilayer ceramic electronic element according to  claim 14 , wherein the applying step and the printing of the step-smoothing paste onto the upper surfaces of the ceramic green sheets are continuously performed while the ceramic green sheets provided on the long base film are conveyed in the length direction thereof.  
     
     
         16 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , wherein the step of printing the step-smoothing paste onto the upper surfaces of the ceramic green sheets is performed after the applying step.  
     
     
         17 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , wherein the applying step is performed after the step of printing the step-smoothing paste onto the upper surfaces of the ceramic green sheets.  
     
     
         18 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , wherein the ceramic green sheets and the step-smoothing ceramic paste primarily form a dielectric ceramic used for a multilayer ceramic capacitor as the multilayer ceramic electronic element.  
     
     
         19 . A method for manufacturing a multilayer ceramic electronic element according to  claim 11 , wherein the laminating step includes forming second ceramic green sheets on the respective ceramic green sheets having the internal electrodes and the step-smoothing ceramic paste for forming three-layered intermediate laminates, and then bonding the intermediate laminates to each other by compression for forming the laminate.  
     
     
         20 . A method for manufacturing a multilayer ceramic electronic element according to  claim 19 , wherein the step-smoothing ceramic paste and the second ceramic green sheets are simultaneously provided so as to obtain the intermediate laminate bodies.