Ceramic electronic component and method of producing the same

Abstract

The present invention provides an electronic component provided with the terminal electrode having a three layer structure comprising a first layer, a second layer and a third layer successively formed on each end face of the main electronic component, the second layer being a porous structure to advantageously absorb the stress caused by expansion and shrinkage of the wiring board, thereby preventing the main electronic component from suffering the stress, and the non-porous first layer maintaining good electrical continuity with the inner electrode while the non-porous third layer serving for preventing permeation of the solder liquid along with maintaining good electrical continuity to the outside, thereby preventing the ceramic component from being mechanically damaged due to expansion and shrinkage applied from the wiring board when the ceramic electronic component is packaged on the wiring board.

What is claimed is:  
     
         1 . A ceramic electronic component comprising a chip of an electronic component containing inner wiring and at least one terminal electrode on an outer surface of the electronic component electrically connected to the inner wiring, wherein 
 the terminal electrode comprises a first layer on an outer surface of the electronic component, a second layer on the outside of the first layer and a third layer on the outside of the second layer, and    wherein the second layer is porous.    
     
     
         2 . A ceramic electronic component according to    claim 1    having two of said terminal electrodes disposed at different sites on the outer surface of the electronic component.  
     
     
         3 . A ceramic electronic component according to    claim 2   , wherein the second layer comprises baked conductive particles of a particle size of about 3 to 6 μm.  
     
     
         4 . A ceramic electronic component according to    claim 3   , wherein the first, second and third layers each comprise baked conductive particles of a particle size of about 0.5 to  2 μm.    
     
     
         5 . A ceramic electronic component according to    claim 2   , wherein the first, second and third layers each comprise baked conductive particles of a particle size of about 0.5 to 2 μm.  
     
     
         6 . A method for producing a chip of a ceramic electronic component having inner wiring electrically connected to a terminal electrode on the outer surface of the electronic component, comprising the steps of: 
 providing said electronic component having inner wiring;    forming a first conductive paste film containing conductive particles to form a first layer by baking on a portion of the outer surface of the electronic component;    forming at the side of the first conductive paste film exterior to the electronic component, a second conductive paste layer containing conductive particles and an additive which burns out when the layer is baked to form a second layer;    forming a third conductive paste layer containing conductive particles to form a third layer by baking at the side of the second conductive paste film exterior to the first layer; and    baking the resulting composite.    
     
     
         7 . A method for producing the ceramic electronic component according to    claim 6   , further comprising the step of adjusting the content of additive in the second conductive paste film in order to obtain a predetermined void ratio in the porous structure of the second layer after baking.  
     
     
         8 . A method for producing the ceramic electronic component according to    claim 7   , wherein the second conductive paste film is dried prior to the step for forming the third conductive paste film, and the second conductive paste film is baked simultaneously with the third conductive paste.  
     
     
         9 . A method for producing the ceramic electronic component according to    claim 8   , wherein the additive comprises gelatin, cellulose or carbon.  
     
     
         10 . A method for producing the ceramic electronic component according to    claim 9   , wherein the second paste film comprises conductive particles having a particle size of about 3 to 6 μm.  
     
     
         11 . A method for producing the ceramic electronic component according to    claim 10   , wherein the first, second and third paste films each comprise conductive particles having a particle size of about 0.5 to 2 μm.  
     
     
         12 . A method for producing the ceramic electronic component according to    claim 7   , wherein the additive comprises gelatin, cellulose or carbon.  
     
     
         13 . A method for producing the ceramic electronic component according to    claim 12   , wherein the second conductive paste film is dried prior to the step for forming the third conductive paste film, and the second conductive paste film is baked simultaneously with the third conductive paste.  
     
     
         14 . A method for producing the ceramic electronic component according to    claim 13   , wherein the second paste film comprises conductive particles having a particle size of about 3 to 6 μm.  
     
     
         15 . A method for producing the ceramic electronic component according to    claim 14   , wherein the first, second and third paste films each comprise conductive particles having a particle size of about 0.5 to 2 μm.  
     
     
         16 . A method for producing the ceramic electronic component according to    claim 6   , wherein the second paste film comprises conductive particles having a particle size of about 3 to 6 μm.  
     
     
         17 . A method for producing the ceramic electronic component according to    claim 16   , wherein the first, second and third paste films each comprise conductive particles having a particle size of about 0.5 to 2 μm.  
     
     
         18 . A method for producing the ceramic electronic component according to    claim 6   , wherein the first, second and third paste films each comprise conductive particles having a particle size of about 0.5 to 2 μm.  
     
     
         19 . A method for producing the ceramic electronic component according to    claim 6   , wherein the second conductive paste film is dried prior to the step for forming the third conductive paste film, and the second conductive paste film is baked simultaneously with the third conductive paste.