Polyimide film, method of manufacture, and metal interconnect board with polyimide film substrate
AssigneeDuPont-Toray Co. Ltd.
InventorsKenji Uhara, Naofumi Yasuda, Kouichi Sawasaki
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Abstract
A polyimide film is produced by copolymerizing pyromellitic dianhydride in combination with phenylenediamine, methylenedianiline and 3,4′-oxydianiline in a specific molar ratio. 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.
Claims4
A polyimide film made from a polyamic acid prepared from a tetracarboxylic dianhydride comprising pyromellitic dianhydride in combination with phenylenediamine, methylenedianiline and 3,4′-oxydianiline such as to satisfy conditions (1-a) to (1-c below:
- 10 mol %≦X≦60 mol % (1-a)
- 20 mol %≦Y≦80 mol % (1-b)
- 10 mol %≦Z≦70 mol % (1-c)
- wherein X is the mole percent of phenylenediamine, Y is the mole percent of methylenedianiline, and Z is the mole percent of 3,4′-oxydianiline, each based on the total amount of diamine, and further wherein the tetracarboxylic dianhydride and total diamine are in a molar ratio of about 0.9 to 1.1, and further wherein the elastic modulus of said film is at least 4 GPa, and said film having a thickness of about 25 μm to about 50 μm.
Dependencies are inferred from the claim text.