Issue link: https://iconnect007.uberflip.com/i/1143487
68 PCB007 MAGAZINE I JULY 2019 Our industry is full of tales describing the work and effort needed to overcome fabrication hurdles to produce a complex design. Manu- facturing a custom product with 100+ pro- cessing steps can be tricky enough, but when you add in a highly complex set of design at- tributes, pour engineering resources into defin- ing the process, and verify that it is repeatable and reliable, that comes with a certain sense of pride and satisfaction. Today, I want to share a case study of one of those types of designs. And while this example will be one of those stories that will be discussed for years to come, it is also a case of something going wrong even when everyone is doing things right. This tale starts approximately three years ago when we reviewed a complex design for a medical application. The product has contact with human skin, requires FDA approval, and was expected to have multiple prototype revi- sions and both test and pre-production runs before going to full production. The design it- self was extremely tricky and required a very specific material set and multiple surface fin- ishes and lamination cycles. Countless hours were spent in engineering discussions, trying to get an understanding of which elements had some flexibility and could be adjusted to make the design more manufacturable and how to overcome the challenges for the elements that had no flexibility. There were three or four re- visions and subsequent engineering reviews to make adjustments after each build. There were several small test lots of these PCBs run as the final product was going through qualification. I think everyone in- volved with the fabrication of that design felt a strong sense of pride and satisfaction when we moved to the pre-production phase with a process and product that was performing well When You Do Everything Right and Something Still Goes Wrong Flex Talk Feature Column by Tara Dunn, OMNI PCB