Chapter 7 – Practical Design Guidelines for Flex
By Joseph Fjelstad and Vern Solberg

Chapter 7 provides a comprehensive overview of the multifaceted process of flexible circuit design. It starts with key preliminary steps such as understanding and setting tolerances, using CAD design tools and special design considerations. Further discussion includes the unique interconnection design features associated with flex circuits, along with an appreciation of ground plane design, polymer thick film design guidelines and other more subtle aspects of flex circuit design
In order to fully understand and carry out successful designs, this chapter addresses potential issues requiring consideration, including: covercoat and coverlayer concerns; tear resistance; stiffeners and reinforcements; strain relief; methods of connection; bending and flexing; and minimum bend radii. Other discussion points found in the chapter include finite element modeling, shielding, membrane switches and controlled impedance constructions.