DuPont Circuit & Packaging Materials Awarded U.S. Patents for Matte Black Film and Coverlay

Matte Polyimide Film Addresses Market Needs, Demonstrates Industry Innovation

DuPont Circuit & Packaging Materials (DuPont), the inventor of polyimide film, has been awarded three new U.S. patents related to DuPont™ Kapton® black polyimide film, and DuPont™ Pyralux® black flexible circuit material, used in applications such as mobile devices, computers, automotive and military electronics.

Matte Polyimide Film Addresses Market Needs

Many of today’s premium smartphones and tablets are designed with flexible circuits using DuPont™ Kapton® black polyimide film as an alternative to traditional amber flexible circuits.

“We are very pleased to announce the issuance of these important U.S. patents for our matte black polyimide films,” said Tim Chang, global business director, DuPont Circuit & Packaging Materials.  “DuPont invented Kapton® polyimide film over 45 years ago and has been innovating with it ever since to meet our customers’ needs.  As we continue to innovate, patents are critical to protect our developments in the United States and abroad.”

The issued patents are related to three key currently available products.  DuPont™ Kapton® FPC-MBC black polyimide film is a homogeneous opaque film that can be used as a substrate or a coverlay.  DuPont™ 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 color 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. 

Using these materials to achieve an opaque coverlay is beneficial for designers in a number of ways.  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 proven to help prevent reflections.  The ability of Kapton® to maintain its excellent physical, electrical and mechanical properties over a wide temperature range makes it ideal for a variety of applications.  

DuPont is currently pursuing additional patents in the United States and abroad for its family of matte and low-gloss polyimide films and coverlays.  The newest patents issued are U.S. Patent Nos. 8,440,315 and 8,574,720, both entitled “Matte Finish Polyimide Films and Methods Relating Thereto,” and U.S. Patent No. 8,541,107, entitled “Pigmented Polyimide Films and Methods Relating Thereto.” Kapton® polyimide film is manufactured only by DuPont and Du Pont-Toray Co. 

DuPont Circuit & Packaging Materials offers a broad and growing portfolio of products including dry film photoresists and phototooling films for Printed Circuit Board (PCB) imagingpolyimide filmsflexible circuit materialsembedded passive materials and thermal substrates for LED lighting.  For information on DuPont circuit materials please visit

DuPont (NYSE: DD) has been bringing world-class science and engineering to the global marketplace in the form of innovative products, materials, and services since 1802.  The company believes that by collaborating with customers, governments, NGOs, and thought leaders we can help find solutions to such global challenges as providing enough healthy food for people everywhere, decreasing dependence on fossil fuels, and protecting life and the environment.  For additional information about DuPont and its commitment to inclusive innovation, please visit