A Flexible Laminate Using Thermoplastic Polyimide
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15
A flexible laminate of polyimide and metal foil formed by pressing the laminate while raising the temperature of the polyimide above its glass transition temperature is described in U.S. Patent #4,411,952. The flexibility of the laminate and the adhesion of the metal foil to the polyimide can be improved if the thermoplastic polyimide used is Pyralin 2566 brand of polyimide available from DuPont. The use of this material also allows the laminate to be made substantially thinner than described in the referenced patent. In the process for making the laminate the liquid Pyralin 2566 is applied to a thin sheet of metal foil, such as copper or stainless steel, and allowed to cure. A second sheet of metal foil is then applied onto the cured polyimide layer.