E.i. Dupont De Nemours and Company

Richard A Wessel

Brian C Auman

Peter Francis Carcia

Harry Richard Zwicker

Christopher Dennis Simone

Yueh-Ling Lee

Carl Robert Haeger

Sidney G Cox

Xin Shane Fang

The present disclosure is directed to a circuit board having a first polyimide coverlay, a first imaged metal layer, a first electrically insulating layer, a second imaged metal layer, a polyimide bondply, a third imaged metal layer, a second electrically insulating layer, a forth imaged metal layer and a second polyimide coverlay. The first polyimide coverlay, the polyimide bondply and the second polyimide coverlay are derived from 100 mole % 3,3',4,4&#x2032;-biphenyl tetracarboxylic dianhydride, 20 to 90 mole % 2,2&#x2032;-bis(trifluoromethyl) benzidine, and 10 to 80 mole % 4,4&#x2032;-oxydianiline.

Circuit board

Perfluorinated polyimides (and co-polyimide) compositions, particularly films are disclosed, comprising at least 50 mole percent of a polymeric repeat unit derived from contacting 3,3',4,4&#x2032;-biphenyltetracarboxylic dianhydride (BDPA) and 2,2&#x2032;-bis(trifluoromethyl) benzidine (TFMB) monomers. The perfluorinated polyimide (and co-polyimide) films of the invention have an in-plane coefficient of thermal expansion (CTE) between &#x2212;5 and +20 ppm/&#xb0; C. and a average light transmittance percent of from about 65.0 to about 99.0 (on a 75-micron thick film basis). The films of the present invention were converted to a polyimide using a chemical conversion method instead of typically employed thermal conversion step thus yielding these desirable properties. The films of the present invention can be an excellent substrate in an optical display device and can be used to replace rigid glass substrates. Finally, the polyimide films of the invention can also be used to manufacture flexible display devices (e.g., cellular phones, personal digital assistants, portable video games, laptops, and the like).

Low color polyimide compositions useful in optical type applications and methods and compositions relating thereto

Growing community of inventors

Raleigh, NC, United States of America

Richard A Wessel