Issue link: https://iconnect007.uberflip.com/i/950499
62 PCB007 MAGAZINE I MARCH 2018 Just the other day, I was recording a pod- cast with Altium discussing flexible circuit cost drivers. During that discussion, I was asked a question about what I see as a trend in the market. My first thought was that I am seeing an increase in frequency of questions com- ing from people that are just new to flex and rigid-flex design. There are enough idiosyncrasies with flex that people are a little unsure and are reaching out with questions. Around this same time, I had been contemplating what would be a good topic to write about for the "New Technology" theme of this month's mag- azine. The light bulb went off; there is such a range of experiences one can have with flex and rigid-flex that even more expe- rienced users can feel like they are working with it for the first time, when in fact they're not. Imagine what it's like for people who are totally unfamil- iar with it! So at the end of the day, brand new to flex and flex- rigid or not, most people who use it feel like they are work- ing with new technology. Single- and Double-Sided Flex Single-layer flex, flex with one layer of cop- per, is a place many new to flexible cir- cuits start. This is used when all conductors can be routed on one layer of copper. This may be replacing wire, solving a packaging problem or even be used for aesthetic reasons in a package that will be visible to the end user. When circuitry can't be routed on a single layer, or shield- ing is needed, the progression is to move to double-sided (two copper layers) flex, or even multilayer flex. If single- and double- sided flexible circuits are a new technology for you, material selection can be daunting. There are many material options to con- sider, but the predomi- nant material is rolled an- nealed copper/polyimide laminate. Within this material type, there are two different options. A d h e s i v e - b a s e d material, with either acrylic adhesive or flame-retardant ad- hesive, or adhesive- less material. Many single- and double- sided designs will use the adhesive-based materials. These ma - terials are often less ex- pensive than the adhe- siveless version. Laminates are typically provided with ½ oz. to 2 oz. copper and ½ mil to 6 mil polyimide. Something New for Everyone Flex Talk Feature Column by Tara Dunn, OMNI PCB