Chip on film, display device, method of fabricating chip on film, apparatus for fabricating chip on film

A chip on film for a display device, the chip on film comprising:

• a base substrate;
• a plurality of lead wires disposed on the base substrate;
• and
• a driving chip connected to the plurality of lead wires,
• wherein each of the plurality of the lead wires includes:
• a first lead part having a first thickness;
• and
• a second lead part disposed between the first lead part and the driving chip and having a second thickness greater than the first thickness, the second lead part being connected to the driving chip,
• wherein the first lead part and the second lead part comprise a same material,
• wherein a surface of the base substrate includes a first base surface overlapping the first lead part, and a second base surface without overlapping the first lead part,
• wherein the second base surface includes a first sub-base surface spaced apart from the first base surface, and a second sub-base surface located between the first sub-base surface and the first base surface,
• wherein the second sub-base surface comprises surface irregularities, and
• wherein a roughness of the second sub-base surface is greater than each of a roughness of the first base surface and a roughness of the first sub-base surface.

A display device comprising:

• a display base substrate;
• a first substrate including a pad disposed on the display base substrate;
• and
• a chip on film connected to the pad,
• wherein the chip on film includes:
• a base substrate;
• a plurality of lead wires disposed on the base substrate and connected to the pad;
• and
• a driving chip connected to the lead wire, and
• wherein each of the plurality of lead wires includes:
• a first lead part having a first thickness;
• and
• a second lead part disposed between the first lead part and the driving chip and having a second thickness greater than the first thickness, the second lead part being connected to the driving chip,
• wherein the first lead part and the second lead part comprise a same material, and
• wherein the base substrate includes a first base part overlapping the first lead part, and a second base part without overlapping the first lead part,
• the second base part includes a first sub-base part spaced apart from the first base part, and a second sub-base part located between the first sub-base part and the first base part, and
• a thickness of the second sub-base part is smaller than each of a thickness of the first base part and a thickness of the first sub-base part.

A method of fabricating a chip on film for a display device, the method comprising the steps of:

• preparing a mother film in which a first portion corresponding to an inside of a cutting line of a rectangular frame shape, and a second portion corresponding to an outside of the cutting line are defined, the mother film including a driving chip mounted on the first portion, and a plurality of lead wires having an in-cutting line wire part disposed in the first portion and connected to the driving chip, and an out-cutting line wire part disposed in the second portion and connected to the in-cutting line wire part;
• laser-processing a portion adjacent to the cutting line in the in-cutting line wire part;
• forming a first lead part adjacent to the cutting line and having a first thickness, and a second lead part disposed between the first lead part and the driving chip and having a second thickness greater than the first thickness, and
• cutting the second portion along the cutting line,
• wherein the mother film includes a first base part overlapping the first lead part, and a second base part without overlapping the first lead part,
• the second base part includes a first sub-base part spaced apart from the first base part, and a second sub-base part located between the first sub-base part and the first base part, and
• a thickness of the second sub-base part is smaller than each of a thickness of the first base part and a thickness of the first sub-base part.