Issue link: https://iconnect007.uberflip.com/i/972396
26 FLEX007 MAGAZINE I APRIL 2018 Flexible circuits are used in applications requiring millions of flex cycles. But this does not suggest they are indestructible. In fact, occurrences of performance issues as the result of fractured traces have been experi - enced in a variety of applications. Solutions are often the result of design, construction, and feature location modifications. But a much better solution is to avoid the problem in the first place! A flexible circuit's ability to be bent, twisted, folded and continuously flexed is a significant advantage offered as a designer considers this interconnect method in a new product. The design options are myriad, with origami-style packaging being an accurate description of how the product is often used. But it is true that improper designs and/or specifications have resulted in bad experience anecdotes about trace fracturing problems. The following are some pitfalls to avoid and help minimize the chance a design will experi- ence premature failure. Creating High-Stress Points There are several ways a designer might inadvertently lay out traces and create a higher level of mechanical stress during bending. Designs with traces on opposite sides of the dielectric laying directly over each other will create an "I-beam affect" (Figure 1). Preferred Construction STAGGERED CONDUCTORS NOT Recommended I-BEAM CONSTRUCTION Figure 1. Staggered conductors are more reliable than the I-beam format. All About Flex by Dave Becker, ALL FLEX