Display device and manufacturing method of base film

A display device, comprising:

• a base film that includes:
• a metal layer having a planar form with a first major surface and a second major surface opposite the first major surface, the metal layer having an integral form such that no internal non-metal layers are between the first major surface and the second major surface;
• a first layer made of a polymer material and having an integral form, the first layer directly bonded to the first major surface without adhesive or an adhesive layer therebetween, and a reactive group on the first major surface directly bonded to a reactive group of the first layer;
• and
• a second layer made of a polymer material and having an integral form, the second layer directly bonded to the second major surface without adhesive or an adhesive layer therebetween, and a reactive group on the second major surface directly bonded to a reactive group of the second layer;
• a display panel positioned on the first layer, the display panel including a substrate that covers the base film with pixels and a transistor disposed directly between the substrate and the first layer, wherein
• a modulus of each of the first layer and the second layer is 1 GPa to 10 GPa,
• the metal layer includes a first metal layer and second metal layer, and a third layer positioned between the first metal layer and the second metal layer,
• the first metal layer is positioned between the first layer and the third layer, and
• the second metal layer is positioned between the second layer and the third layer.