Chip on film package

A chip on film package, comprising:

• a chip comprising a plurality of bumps disposed on an active surface of the chip;
• and
• a flexible film, wherein the chip is mounted on the flexible film via the active surface, and the flexible film comprises:
• a plurality of first vias penetrating the flexible film;
• a plurality of second vias penetrating the flexible film, wherein the first vias and the second vias are arranged on two opposite sides of a first side of a reference line respectively and the second vias are arranged on a second side of the reference line, wherein a distance between one of the first vias and one of the second vias, which are closer to a first side of the chip, is longer than that between another one of the first vias and another one of the second, which are further from the first side of the chip;
• a plurality of upper leads disposed on the upper surface connected between the first vias and the bumps and between the second vias and the bumps;
• and
• a plurality of lower leads disposed on the lower surface, connected to the first vias and the second vias, and extending toward the first side or a second side of the chip opposite to the first side.