The invention provides a polyimide film manufactured from a polyamic acid prepared
from pyromellitic dianhydride in combination with 10 to 60 mol % of phenylenediamine
and 40 to 90 mol % of 3,4-oxydianiline, based on the overall diamine. The
polyimide film, when used as a metal interconnect board substrate in flexible circuits,
chip scale packages (CSP), ball grid arrays (BGA) or tape-automated bonding (TAB)
tape by providing metal interconnects on the surface thereof, achieves a good balance
between a high elastic modulus, a low thermal expansion coefficient, alkali etchability
and film formability.
