E.i. Dupont De Nemours and Company

John A Kreuz

Stuart N Milligan

Kuppusamy Kanakarajan

Richard F Sutton, Jr

Brian C Auman

John R Dodd

Christopher M Hawkins

Segmented, melt-processible, semicrystalline copolyimides are disclosed herein. These polymers are comprised of an amorphous or semicrystalline A segment (soft segment) and a semicrystalline B segment (hard segment), wherein the level of semicrystallinity in the A segment is less than that in the B segment. These copolyimides are semicrystalline and exhibit melting points in the range from about 330-395&deg; C. In preferred embodiments, these copolyimides are end-capped and are crystallizable from their melts (i.e., they exhibit recoverable semicrystallinity). These copolyimides either inherently have suitably low melt visocosities to be melt-processible or can be made to have suitably low melt viscosities to be melt-processible by addition of certain additives. Tailoring of the melting points and glass transition temperatures of these copolyimides can be effected by changing their molecular architecture.

Melt-processible semicrystalline block copolyimides

A process of making flexible multilayer polyimide metal-clad laminates, and their preparation, having at least one layer of aromatic polyimide bonded to at least one layer of a metallic substrate using a heat-sealable copolyimide adhesive containing repeating imide units derived from 4,4'-oxydiphthalic dianhydride and an aromatic ether diamine. The laminates are used in flexible printed circuits and tape automated bonding applications. Additionally, the metallic substrate may be directly coated with the copolyimide adhesive and used as a single-clad laminate for flexible printed circuits.

Flexible multi-layer polyimide film laminates and preparation thereof

Flexible multilayer polyimide metal-clad laminates, and their preparation, having at least one layer of aromatic polyimide bonded to at least one layer of a metallic substrate using a heat-sealable copolyimide adhesive containing repeating imide units derived from 4,4'-oxydiphthalic dianhydride and an aromatic ether diamine. The laminates are used in flexible printed circuits and tape automated bonding applications. Additionally, the metallic substrate may be directly coated with the copolyimide adhesive and used as a single-clad laminate for flexible printed circuits.

Tetrapolyimide films derived from oxydiphthalic dianhydride, pyromellitic acid dianhydride, p-phenylene diamine and 4,4'-diaminodiphenyl ether, and their preparation are described. The tetrapolymer films have low water absorption, low coefficients of thermal and hygroscopic expansion, high modulus and are caustic etchable and can be used in flexible printed circuit and tape automated bonding applications.

Tetrapolyimide film containing oxydipthalic dianhydride

Tetrapolyimide films derived from 3,3',4,4'-benzophenone tetracarboxylic dianhydride, pyromellitic acid dianhydride, p-phenylene diamine and 4,4'-diaminodiphenyl ether, and their preparation, are described. The tetrapolymer films have low water absorption, low coefficients of thermal and hygroscopic expansion, high modulus and are caustic etachable and can be used in flexible printed circuit and tape automated bonding applications.

Tetrapolyimide film containing benzophenone tetracarboxylic dianhydride

Aromatic homopolyimide and copolyimide films derived from an aromatic dianhydride and a chlorinated aromatic diamine such as 2-chloro-p-phenylene diamine and 2,2'-dichloro-4,4'-diaminodiphenyl ether are described. The films have low water absorption, high elastic modulus and elongation and can be heat-processed without embrittlement.

Aromatic homopolyimide or copolyimide films having low water absorption

Disclosed is an aromatic copolyimide film prepared by chemical conversion of a copolyamide acid solution obtained by copolymerization of an aromatic tetracarboxylic acid component comprising from 30 to 50 mole % of biphenyltetracarboxylic acid dianhydride, 50 to 70 mole % of pyromellitic acid dianhydride, 60 to 80 mole % of p-phenylenediamine and 20 to 40 mole % of 4,4'-diaminodiphenyl ether. The aromatic copolyimide film has a low coefficient of thermal expansion, low water absorption, a low coefficient of hygroscopic expansion, high mechanical strength and is readily etchable making it suitable for use an advanced electronic substrate.

Copolyimide film with improved properties

An aqueous solution of ethyl or propyl alcohol containing a basic compound such as KOH is shown to etch the surface of polyimide material up to 400 times faster than conventional aqueous KOH etching solutions.

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Columbus, OH, United States of America

John A Kreuz