Issue link: https://iconnect007.uberflip.com/i/793332
10 SMT Magazine • March 2017 found to be the key industry sectors seeing in- creased use of flexible circuits, as per our survey. Also, most respondents consider the design of the flex circuit, the handling, and soldering processes as among the key factors that have the biggest effect on yields. Another issue is moisture control. In a short email interview, Brian Tracey, group vice presi- dent of business development at Interplex In- dustries Inc.—a provider of design and manu- facturing services for custom flex circuit assem- bly—says the hydroscopic nature of the flex circuit makes it difficult to process, therefore drying the flex circuits prior to soldering can help improve yields. Directly related to this is the soldering process, which he considers as a key process step that has the biggest effect on yield as it can sometimes create solder voids, cold solder joints or incomplete circuits. Meanwhile, Tracey notes that the limita- tions with the adhesives used between the in- sulation and copper layers offer a major chal- lenge in flex circuit assembly as these adhesives are sensitive to water absorption as well as heat, which can break down the adhesive layers and cause the traces to fracture. Regarding new technologies that will signif- icantly benefit the flexible printed circuit pro- cess, Tracey says they are seeing potential ben- efits in including direct solder attachment to leads as well as utilizing eye-of-the-needle press- fit technology to further expand the range of manufacturing solutions for their custom- ers. He adds that they are starting to see slight improvements in materials used to produce the flex circuits that is helping with overall yields throughout the process. This issue of SMT Magazine features articles and interviews with companies such as Saline Lectronics, Tramonto Circuits, Firstronic, JJS Manufacturing, Spectrum Assembly Inc., and Screaming Circuits, about flexible circuit assem- bly challenges, as well as strategies to help you address your pain points. Contributors provide important points to consider when selecting an electronics contract manufacturing partner for your flex printed circuit assembly. Regular columnists Michael Ford, Rich Heimsch, Tom Borkes, and Bob Wettermann provide their expert views on the latest issues in the electronics assembly industry. Finally, we also have interesting articles from Microcare, which discusses flexible clean- ing methods, and PCBCart, which provides pointers on how to evaluate a PCB assembler. By the way, we had a great show last month at the IPC APEX EXPO 2017 event in San Diego. Our booth featured a micro studio, where we did more than 70 in-depth Real Time with…IPC interviews. We also created a time-lapse video, which is made up of over 50,000 photos taken from the event setup to closing. So if you didn't make it to IPC APEX EXPO this year, just visit our RealTimewith…IPC APEX EXPO 2017 site to get all the show coverage and view the event photo gallery. SMT Stephen Las Marias is managing editor of SMT Magazine. He has been a technology editor for more than 12 years covering electronics, components, and industrial automation systems. NAVIGATING THE COMPLEX WORLD OF FLEX CIRCUIT ASSEMBLY