Flex Talk: Troubleshooting Flex Circuit Applications for Mil/Aero Projects
October 6, 2016 | Tara Dunn, OMNI PCBEstimated reading time: 1 minute
![](https://iconnect007.com/application/files/1516/3116/7464/tara_dunn250.jpg)
I imagine that everyone has been in this position at one time or another: Despite everyone’s best attempt at creating the perfect design, PCB fabrication and assembly, something goes wrong and the troubleshooting begins.
I had the opportunity to sit down with Ed Knutson, the president and founder of Dimation, to swap some of our best war stories. Ed specializes in quick-turn assembly and design. Our banter, to which I brought the fabrication piece of the puzzle, was primarily focused on flexible circuit applications for mil/aero projects. I am not sure if that is because of the more stringent requirements for those applications or because we both work regularly in that industry segment. At the end of our discussion, we concluded that most of our war stories could be traced back to a breakdown in communication and often simply not fully understanding how each piece of the design-fabrication-assembly puzzle fits together. Here are a few of our stories and lessons learned.
UL Materials
Aircraft applications typically require materials rated to UL94V-0. The assembly is complete and the burn test fails. What happened? The perfect storm. When the design files were created for fabrication and assembly, the UL requirements were noted in the assembly files only and called out by test requirements, not UL 94V-0. This was an ITAR application, so the PCB fab files were separated from the assembly files and forwarded to the flex manufacturer. Because there were no UL requirements listed on the fabrication notes, the supplier defaulted to their standard materials and the flex was not built with flame-retardant materials. That explains why the final assembly failed the burn test. Lesson Learned: Always clearly communicate UL requirements and include the requirement in both the PCB fabrication notes and the assembly notes.
To read this entire article, which appeared in the September 2016 issue of The PCB Magazine, click here.
Suggested Items
I-Connect007 Editor's Choice: Five Must-Reads for the Week
09/06/2024 | Nolan Johnson, I-Connect007This week’s Top 5 starts with steps you can take to cultivate a culture of thriving. We also have bullish news from the global semiconductor sector, advice on how to tease out hidden cost drivers during the PCB design cycle, how the Altium-Ansys collaboration will affect design, and Happy Holden’s version of Occam’s Razor—three simple tools to keep your wet processes in line.
Impact of the Altium-Ansys Partnership on PCB Design
09/05/2024 | Josh Moore, AltiumThere’s a saying in electronics hardware design: “There are two types of electronics designers: those who have signal integrity problems and those who will.” This adage emphasizes the inevitability of encountering and the need to address signal integrity (SI) and power integrity (PI) issues.
Hidden Cost Drivers in PCB Design
09/05/2024 | Cherie Litson, CID+, Litson1 ConsultingI recently taught a CID+ course, and if you’ve ever taken a CID or CID+ course, you know that we discuss cost adders quite a bit. When I asked the class of 15 design engineers their ideas on the biggest cost adders, the first and strongest response: the project manager. Are you surprised by their answer? After over 40 years in the industry, I wasn’t. If you step back and look at the process of product development, you’ll see that many decisions that affect costs down the line really do take root with the project manager.
Altium, Mouser Team Up to Advance Electronics Education and Careers Worldwide
09/05/2024 | AltiumAltium LLC, a global leader in software and solutions for the electronics industry, and Mouser Electronics, a global authorized distributor of semiconductors and electronic components, are excited to announce a strategic partnership aimed at advancing electronics education and careers worldwide.
Young Professionals Spotlight: Process Engineer Kevin Dial, American Standard Circuits
09/05/2024 | Dan Beaulieu, D.B. Management GroupWhen I heard that my friends at American Standard Circuits had hired a new, fresh-out-of-college process engineer, I was anxious to meet him. Now, you get to read this interview. It’s a rare perspective of a young man new to our industry.