Organic EL display device and method for manufacturing the same

An organic EL display device comprising:

• a substrate;
• an underlying layer formed on said substrate, said underlying layer including a flattening layer formed of organic materials and a passivation layer formed on the flattening layer and the substrate;
• organic EL elements formed on the passivation layer of said underlying layer;
• leading electrodes drawn out from said organic EL element for electrically connecting with an electrode of an interconnection object on said substrate;
• and
• connecting regions wherein the flattening layer composing said underlying layer at a location corresponding to a location of thermo-compression bonding is removed for electrically connecting said leading electrode with said electrode of the interconnection object without fail,
• wherein a flattening layer removal surface of the underlying layer adjacent to the connection region has an upward tapered surface inclined relative to the substrate.