Organic electroluminescent device and method for producing same

An organic electroluminescent device, comprising:

• a substrate;
• a driving circuit layer including a plurality of TFTs formed on the substrate, a plurality of gate bus lines, a plurality of source bus lines, a plurality of terminals, and a plurality of lead wires, each of the plurality of TFTs being connected one of the plurality of gate bus lines and one of the plurality of source bus lines, and each of the plurality of lead wires connecting one of the plurality of terminals and one of the plurality of gate bus lines, or one of the plurality of terminals and one of the plurality of source bus lines;
• an interlayer insulating layer formed on the driving circuit layer;
• an organic electroluminescent element layer formed on the interlayer insulating layer and including a plurality of organic electroluminescent elements each connected with one of the plurality of TFTs;
• and
• a thin film encapsulation structure formed so as to cover the organic electroluminescent element layer,
• wherein the interlayer insulating layer includes a contact hole,
• wherein in the contact hole, a contact portion connecting the driving circuit layer and the organic electroluminescent element layer to each other is formed,
• wherein a surface of the interlayer insulating layer and a surface of the contact portion are flush with each other, and each have an arithmetic average roughness Ra of 50 nm or less,
• wherein the interlayer insulating layer is formed on the driving circuit layer, and includes a first inorganic protective layer exposing at least the plurality of terminals, an organic flattening layer formed on the first inorganic protective layer, and a second inorganic protective layer formed on the organic flattening layer,
• wherein the second inorganic protective layer has a surface having an arithmetic average roughness Ra of 50 nm or less,
• wherein the thin film encapsulation structure includes a first inorganic barrier layer, an organic barrier layer in contact with a top surface of the first inorganic barrier layer and a second inorganic barrier layer in contact with a top surface of the organic barrier layer, the organic barrier layer being formed in a region enclosed by an inorganic barrier layer joint portion where the first inorganic barrier layer and the second inorganic barrier layer are in direct contact with each other,
• wherein as viewed in a direction of normal to the substrate, the organic flattening layer is formed in a region where the first inorganic protective layer is formed, the plurality of organic electroluminescent elements are located in a region where the organic flattening layer is formed, an outer perimeter of the thin film encapsulation structure crosses the plurality of lead wires and is present between an outer perimeter of the organic flattening layer and an outer perimeter of the first inorganic protective layer, and
• wherein in a portion where the first inorganic protective layer and the first inorganic barrier layer are in direct contact with each other on the plurality of lead wires, a side surface of a cross-sectional shape, of the first inorganic barrier layer, that is parallel to a line width direction of the plurality of lead wires has a tapering angle of less than 90 degrees.