Polyimide film, method of manufacture , and metal interconnect board with Polyimide film substrate

• US 20020045033A1
• Filed: 08/09/2001
• Published: 04/18/2002
• Est. Priority Date: 08/24/2000
• Status: Active Grant

• Current Assignee: Dupont-Toray Co., Ltd.
• Original Assignee: Dupont-Toray Co., Ltd.
• Inventors: Sawasaki, Kouichi, Uhara, Kenji, Yasuda, Naofumi
• Granted Patent: US 6,548,179 B2
• Time in Patent Office: Days
• US Class Current: 428/195.1
• CPC Class Codes: C08G 73/1042 Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds
• CPC Class Codes: C08J 2379/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: H05K 1/0346 containing N
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24917 including metal layer
• CPC Class Codes: Y10T 428/31721 Of polyimide

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.

Claims

1. 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.

2. The polyimide film of claim 1 which is made from a polyamic acid selected from a block component-containing polyamic acid and an interpenetrating polymer network component-containing polyamic acid.

3. The polyimide film of claim 1 or 2, wherein the phenylenediamine is p-phenylenediamine.

7. A metal interconnect board for use in flexible printed circuits or tape-automated bonding tape, which board is produced by using the polyimide film of claim 1 as the substrate and providing metal interconnects on the surface thereof.

4. A method of manufacturing a polyimide film, the method comprising the steps of, in order:

(A) reacting starting materials comprising (a1) a tetracarboxylic acid dianhydride comprising pyromellitic dianhydride and (a2) a first diamine selected from phenylenediamine, methylenedianiline and 3,4′

-oxydianiline, in an inert solvent to form a first polyamic acid containing a component selected from a block component of the first diamine and pyromellitic dianhydride and an interpenetrating polymer network component of the first diamine and pyromellitic dianhydride;

(B) adding to the first polyamic acid prepared in step A additional materials comprising (b1) a tetracarboxylic acid dianhydride comprising pyromellitic dianhydride and (b2) a second diamine and a third diamine selected from phenylenediamine, methylenedianiline and 3,4′

-oxydianiline, and continuing the reaction with all the materials;

(C) mixing into the second polyamic acid solution obtained in step B a chemical agent capable of converting the polyamic acid into polyimide;

(D) casting or extruding the mixture from step C onto a smooth surface to form a polyamic acid-polyimide gel film; and

(E) heating the gel film at 200 to 500°

C. to transform the polyamic acid to polyimide;

wherein at least one of the first diamine, second diamine and third diamine is a phenylenediamine;

at least one of the first diamine, second diamine and third diamine is a methylenedianiline; and

at least one of the first diamine, second diamine and third diamine is 3,4′

-oxydianiline.

5. The method of claim 4, wherein conditions (1-a) to (1-c) below are satisfied:

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.

6. The method of claim 5, wherein conditions (2-a) to (2-c) below are satisfied:

20 mol %≦

X≦

50 mol % 

 

(2-b)30 mol %≦

Y≦

70 mol % 

 

(2-c)10 mol %≦

Z≦

50 mol % 

 

(2-d)

wherein the tetracarboxylic dianhydride and total diamine are in a molar ratio of about 0.98 to 1.02.