DuPont gains recognition of new electronics uses for polyimide material

November 18, 2013 // By Graham Prophet
DuPont Circuit & Packaging Materials has been awarded three new U.S. patents related to DuPont Kapton black polyimide film, and DuPont Pyralux black flexible circuit material: many of today’s premium smartphones and tablets are designed with flexible circuits using Kapton black polyimide film as an alternative to traditional amber flexible circuits.

The issued patents are related to three key currently available products. Kapton FPC-MBC black polyimide film is a homogeneous opaque film that can be used as a substrate or a coverlay. Pyralux HXC flexible circuit material is the accompanying pre-coated coverlay with an epoxy adhesive coated on one side, ready to be bonded. Pyralux LF-B is the acrylic coverlay variety of matte black polyimide film. The matte black colour of these materials provides a uniform, aesthetically pleasing appearance to flexible printed circuit materials while also maintaining key physical properties such as dielectric strength, tensile strength and dimensional stability, the company says.

Benefits include; the black finish of the films may help prevent reverse engineering of the circuits it covers, as it makes it difficult to determine the exact construction of the underlying circuit traces. Additionally, some fabricators have found that the opacity of Kapton MBC and Pyralux HXC black film may provide higher yields and cost savings in certain applications. In optical applications such as headlamps and camera flashes, these matte films have helped prevent reflections. Kapton maintains its physical, electrical and mechanical properties over a wide temperature range.