Organic Light Emitting Diode Display and Manufacturing Method of Organic Light Emitting Diode Display

Abstract

An organic light emitting diode (OLED) display includes: a substrate; an organic light emitting diode on the substrate; and a thin film encapsulation layer including a first inorganic layer having a first density on the substrate and a second inorganic layer having a second density on the first inorganic layer, the second density being different from the first density, and the organic light emitting diode being encapsulated between the thin film encapsulation layer and the substrate.

1 . An organic light emitting diode (OLED) display comprising:
 a substrate;   an organic light emitting diode on the substrate; and   a thin film encapsulation layer comprising a first inorganic layer having a first density on the substrate and a second inorganic layer having a second density on the first inorganic layer, the second density being different from the first density, and the organic light emitting diode being encapsulated between the thin film encapsulation layer and the substrate.   
     
     
         2 . The OLED display of  claim 1 , wherein the first inorganic layer and the second inorganic layer comprise a same inorganic material. 
     
     
         3 . The OLED display of  claim 2 , wherein the inorganic material comprises at least one material selected from the group consisting of aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), zirconium oxide (ZrO), silicon oxide (SiO 2 ), aluminum oxynitride (AlON), aluminum nitride (AlN), silicon oxynitride (SiON), silicon nitride (Si 3 N 4 ), zinc oxide (ZnO), tantalum oxide (Ta 2 O 5 ), and combinations thereof. 
     
     
         4 . The OLED display of  claim 1 , wherein the first density is greater than the second density, and internal stress of the first inorganic layer is greater than that of the second inorganic layer. 
     
     
         5 . The OLED display of  claim 1 , wherein the second density is greater than the first density, and internal stress of the second inorganic layer is greater than that of the first inorganic layer. 
     
     
         6 . The OLED display of  claim 1 , wherein the first inorganic layer and the second inorganic layer contact each other. 
     
     
         7 . The OLED display of  claim 1 , wherein the thin film encapsulation layer further comprises an intermediate layer between the organic light emitting diode and the first inorganic layer, between the first inorganic layer and the second inorganic layer, or above the second inorganic layer. 
     
     
         8 . The OLED display of  claim 7 , wherein the intermediate layer has at least one of a first surface contacting the first inorganic layer or a second surface contacting the second inorganic layer, and
 the intermediate layer has a first density that is gradually changed from another density from another surface of the intermediate layer to the first surface, has a second density that is gradually changed from the first density from the first surface of the intermediate layer to the second surface, or has another density that is gradually changed from the second density from the second surface of the intermediate layer to yet another surface.   
     
     
         9 . The OLED display of  claim 8 , wherein the intermediate layer comprises an inorganic material that is the same as that of the first and second inorganic layers. 
     
     
         10 . The OLED display of  claim 1 , wherein each of the first and second inorganic layers is formed through an ALD process. 
     
     
         11 . A manufacturing method of an organic light emitting diode (OLED) display, the method comprising:
 forming an organic light emitting diode on a substrate; and   forming a thin film encapsulation layer encapsulating the organic light emitting diode with the substrate on the substrate by forming a first inorganic layer using a deposition process on the substrate in a first temperature environment and forming a second inorganic layer using a deposition process on the first inorganic layer in a second temperature environment that is different from the first temperature environment.   
     
     
         12 . The manufacturing method of  claim 11 , wherein the first inorganic layer and the second inorganic layer are formed using a same inorganic material. 
     
     
         13 . The manufacturing method of  claim 12 , wherein the inorganic material comprises a material selected from the group consisting of aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), zirconium oxide (ZrO), silicon oxide (SiO 2 ), aluminum oxynitride (AlON), aluminum nitride (AlN), silicon oxynitride (SiON), silicon nitride (Si 3 N 4 ), zinc oxide (ZnO), tantalum oxide (Ta 2 O 5 ), and combinations thereof. 
     
     
         14 . The manufacturing method of  claim 11 , wherein a temperature of the first temperature environment is lower than that of the second temperature environment. 
     
     
         15 . The manufacturing method of  claim 11 , wherein a temperature of the second temperature environment is lower than that of the first temperature environment. 
     
     
         16 . The manufacturing method of  claim 11 , wherein the second inorganic layer is formed to contact the first inorganic layer. 
     
     
         17 . The manufacturing method of  claim 11 , wherein the forming of the thin film encapsulation layer further comprises forming an intermediate layer between the organic light emitting diode and the first inorganic layer, between the first inorganic layer and the second inorganic layer, or on the second inorganic layer. 
     
     
         18 . The manufacturing method of  claim 17 ,
 wherein the intermediate layer comprises at least one of a first surface contacting the first inorganic layer or a second surface contacting the second inorganic layer, and the intermediate layer is formed in the first temperature environment that gradually changes from a temperature at a surface of the intermediate layer to the first surface, formed in the second temperature environment that gradually changes from a first temperature of the first surface of the intermediate layer to the second surface, or formed in another temperature environment that gradually changes from a second temperature of the second surface of the intermediate layer to yet another surface.   
     
     
         19 . The manufacturing method of  claim 18 , wherein the intermediate layer is formed using an inorganic material that is the same as that of the first and second inorganic layers. 
     
     
         20 . The manufacturing method of  claim 11 , wherein the deposition process comprises an ALD process.