Method of manufacturing an ink jet recording head having reduced stress concentration near the boundaries of the pressure generating chambers

Abstract

AnA method of manufacturing an ink-jet recording head comprising:which includes an elastic sheet providingfacing pressure generating chambers;, nozzle orifices, each communicating with the pressure generating chambers;, and piezoelectric vibrators formed on the elastic sheet, each of the piezoelectric vibrators having, a lower electrode formed on the elastic sheet, the method including forming a piezoelectric layer formed on the lower electrode, and forming an upper electrode formed on the piezoelectric layer such that the upper electrode faces the respective pressure generating chamber, wherein thearea where the lower electrode, piezoelectric layer and upper electrode overlap is located within an area defined by the pressure generating chamber in the longitudinal direction thereof. The upper electrodes of the piezoelectric vibrators are positioned independently of each other;and an electrical insulator layer having windows, wherein the electrical insulator layer coversis formed to cover the upper electrodes;, and a conductor pattern connecting withis connected to the upper electrodes via the windows of the electrical insulator layer.

1. An ink jet recording head comprising:
 an elastic sheet facing pressure generating chambers;    nozzle orifices communicating with the pressure generating chambers;    piezoelectric vibrators formed on the elastic sheet, each of the piezoelectric vibrators having, 
 a lower electrode formed on the elastic sheet,  
 a piezoelectric layer formed on the lower electrode, and  
 an upper electrode formed on the piezoelectric layer such that the upper electrode faces a respective pressure generating chamber, wherein the upper electrodes of the piezoelectric vibrators are positioned independently of each other;  
   an insulator layer having windows, wherein the insulator layer is formed on a portion of the upper electrodes; and    a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.    
     
     
       2. The ink-jet recording head according to  claim 1 , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows. 
     
     
       3. The ink-jet recording head according to  claim 1 , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer. 
     
     
       4. The ink-jet recording head according to  claim 1 , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material. 
     
     
       5. The ink-jet recording head according to  claim 4 , wherein the insulator layer is made of a polyimide. 
     
     
       6. An ink-jet recording head according to  claim 1 , wherein the insulator layer is formed of an etchant resistant film which is used as a protective film at etching. 
     
     
       7. An ink jet recording head comprising:
 an elastic sheet facing pressure generating chambers;    nozzle orifices communicating with the pressure generating chambers;    piezoelectric vibrators formed on the elastic sheet, each of the piezoelectric vibrators having, 
 a lower electrode formed on the elastic sheet,  
 a piezoelectric layer formed on the lower electrode, and  
 an upper electrode formed on the piezoelectric layer such that the upper electrode faces the respective pressure generating chamber, wherein the piezoelectric layer and the upper electrode are formed entirely inside of areas facing the respective pressure generating chamber;  
   an insulator layer having windows, wherein the insulator layer is formed on a portion of the upper electrodes; and    a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.    
     
     
       8. The ink-jet recording head according to  claim 7 , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows. 
     
     
       9. The ink-jet recording head according to  claim 7 , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer. 
     
     
       10. The ink-jet recording head according to  claim 7 , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material. 
     
     
       11. The ink-jet recording head according to  claim 10 , wherein the insulator layer is made of a polyimide. 
     
     
       12. An ink-jet recording head according to  claim 7 , wherein the insulator layer is formed of an etchant resistant film which is used as a protective film at etching. 
     
     
       13. A method of forming an ink jet recording head, comprising an elastic sheet facing pressure generating chambers, nozzle orifices communicating with the pressure generating chambers, and piezoelectric vibrators formed on the elastic sheet by a film deposition technique, said method comprising:
   forming a lower electrode on the elastic sheet;        defining a first area in a longitudinal direction of each of the pressure generating chambers;        defining a second area in a width direction of each of the pressure generating chambers;        forming a piezoelectric layer on the lower electrode; and        forming an upper electrode on the piezoelectric layer,        wherein an area where said lower electrode, said piezoelectric layer and said upper electrode overlap is located within said first area, and        an area of each of said pressure generating chambers is gradually increased in the longitudinal direction away from said area of overlap.     
     
     
       14. A method of forming the ink jet recording head of  claim 13 , wherein the piezoelectric layer is formed in each of the pressure generating chambers. 
     
     
       15. A method of forming the ink jet recording head of  claim 13 , wherein the upper electrode is formed in a substantially same shape as the piezoelectric layer. 
     
     
       16. A method of forming the ink jet recording head according to  claim 13 , said method further comprising:
   forming, on a portion of the upper electrodes, an insulator layer having windows; and        forming a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.     
     
     
       17. A method of forming the ink- jet recording head according to    claim 16   , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows.   
     
     
       18. A method of forming the ink- jet recording head according to    claim 16   , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer.   
     
     
       19. A method of forming the ink- jet recording head according to    claim 16   , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material.   
     
     
       20. A method of forming the ink- jet recording head according to    claim 19   , wherein the organic material of the insulator layer is polyimide.   
     
     
       21. A method of forming the ink jet recording head according to  claim 13 , said method further comprising:
   forming, on a portion of the upper electrodes, an insulator layer having windows; and        forming a conductor pattern connecting with the upper electrodes through the windows of the insulator layer,        wherein the piezoelectric layer and the upper electrode are formed entirely inside of areas facing the respective pressure generating chamber.     
     
     
       22. A method of forming the ink- jet recording head according to    claim 21   , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows.   
     
     
       23. A method of forming the ink- jet recording head according to    claim 21   , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer.   
     
     
       24. A method of forming the ink- jet recording head according to    claim 21   , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material.   
     
     
       25. A method of forming the ink- jet recording head according to    claim 24   , wherein the organic material of the insulator layer is polyimide.   
     
     
       26. A method of forming the ink- jet recording head according to    claim 21   , wherein the insulator layer is formed of an etchant resistant film which is used as a protective film at etching.   
     
     
       27. A method of forming the ink jet recording head of  claim 13 , further comprising forming said pressure generating chambers in a silicon substrate. 
     
     
       28. A method of forming an ink jet recording head, comprising
   an elastic sheet facing pressure generating chambers, nozzle orifices communicating with the pressure generating chambers, and piezoelectric vibrators formed on the elastic sheet, said method comprising:      forming a lower electrode on the elastic sheet;        forming a piezoelectric layer on the lower electrode;        forming an upper electrode on the piezoelectric layer such that the upper electrode faces a respective pressure generating chamber, wherein the upper electrodes of the piezoelectric vibrators are positioned independently of each other;          forming on a portion of the upper electrodes, an insulator layer having windows; and        forming a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.     
     
     
       29. A method of forming the ink- jet recording head according to    claim 28   , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows.   
     
     
       30. A method of forming the ink- jet recording head according to    claim 28   , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer.   
     
     
       31. A method of forming the ink- jet recording head according to    claim 28   , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material.   
     
     
       32. A method of forming the ink- jet recording head according to    claim 31   , wherein the organic material of the insulator layer is polyimide.   
     
     
       33. A method of forming the ink- jet recording head according to    claim 28   , wherein the insulator layer is formed of an etchant resistant film which is used as a protective film at etching.   
     
     
       34. A method of forming the ink- jet recording head according to    claim 16   , wherein the insulator layer is formed of an etchant resistant film which is used as a protective film at etching.   
     
     
       35. A method of forming an ink jet recording head, comprising
   an elastic sheet facing pressure generating chambers, nozzle orifices communicating with the pressure generating chambers, and piezoelectric vibrators formed on the elastic sheet, said method comprising:      forming a lower electrode on the elastic sheet;        forming a piezoelectric layer on the lower electrode;        forming an upper electrode on the piezoelectric layer such that the upper electrode faces the respective pressure generating chamber, wherein the piezoelectric layer and the upper electrode are formed entirely inside of areas facing the respective pressure generating chamber;        forming, on a portion of the upper electrodes, an insulator layer having windows; and        forming a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.       
     
     
       36. A method of forming the ink- jet recording head according to    claim 35   , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows.   
     
     
       37. A method of forming the ink- jet recording head according to    claim 35   , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer.   
     
     
       38. A method of forming the ink- jet recording head according to    claim 35   , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material.   
     
     
       39. A method of forming the ink- jet recording head according to    claim 38   , wherein the organic material of the insulator layer is polyimide.   
     
     
       40. A method of forming the ink- jet recording head according to    claim 35   , wherein the insulator layer is formed of an etchant resistant film which is used as a protective film at etching.   
     
     
       41. An ink- jet recording head comprising:      an elastic sheet facing pressure generating chambers;        nozzle orifices communicating with the pressure generating chambers;        piezoelectric vibrators formed on the elastic sheet, each of the piezoelectric vibrators comprising:      a lower electrode formed on the elastic sheet,        a piezoelectric layer formed on the lower electrode, and        an upper electrode formed on the piezoelectric layer such that the upper electrode faces a respective pressure generating chamber, wherein the upper electrodes of the piezoelectric vibrators are positioned independently of each other;          an insulator layer having windows, wherein the insulator layer is formed on a portion of the upper electrode; and        a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.     
     
     
       42. The ink- jet recording head according to    claim 41   , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows.   
     
     
       43. The ink- jet recording head according to    claim 41   , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer.   
     
     
       44. The ink- jet recording head according to    claim 41   , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material.   
     
     
       45. The ink- jet recording head according to    claim 44   , wherein the insulator layer is made of a polyimide.   
     
     
       46. The ink- jet recording head according to    claim 41   , wherein the insulator layer is formed of an etchant - resistant film which is used as a protective film at etching.   
     
     
       47. An ink- jet recording head comprising:      an elastic sheet facing pressure generating chambers;        nozzle orifices communicating with the pressure generating chambers;        piezoelectric vibrators formed on the elastic sheet, each of the piezoelectric vibrators comprising:      a lower electrode formed on the elastic sheet,        a piezoelectric layer formed on the lower electrode, and        an upper electrode formed on the piezoelectric layer such that the upper electrode faces the respective pressure generating chamber, wherein the piezoelectric layer and the upper electrode are formed entirely inside of areas facing the respective pressure generating chamber;          an insulator layer having windows, wherein the insulator layer is formed on a portion of the upper electrodes; and        a conductor pattern connecting with the upper electrodes through the windows of the insulator layer.     
     
     
       48. The ink- jet recording head according to    claim 47   , wherein the conductor pattern is formed on a lateral side of the upper electrode between the pressure generating chambers and connected to said upper electrode at more than one site through the windows.   
     
     
       49. The ink- jet recording head according to    claim 47   , wherein the windows extend to a peripheral edge of each of the piezoelectric layers such that the windows do not interfere with the displacement of the vibrating region of the piezoelectric layer.   
     
     
       50. The ink- jet recording head according to    claim 47   , wherein the insulator layer is made of either one of a silicon oxide, a silicon nitride and an organic material.   
     
     
       51. The ink- jet recording head according to    claim 50   , wherein the insulator layer is made of a polyimide.   
     
     
       52. The ink- jet recording head according to    claim 47   , wherein the insulator layer is formed of an etchant - resistant film which is used as a protective film at etching.