Wire Assembly with Epoxy Coating
Challenge: Combine an existing PCB with an existing molded assembly, utilizing a metal dome for a tactile switch. The switch had to be activated by the edge of the PCB instead of a fingertip and the unit had to withstand 100% humidity and extreme heat for 10 days. Not only did the unit have to successfully withstand extreme heat and humidity, but also hold up during a four foot drop test.
Solution: First, we had to devise a way to fully enclose the switch so that the humidity could not penetrate. At the same time, an escape route for the compressed air during switch activation was needed. We managed to accomplish consistent, reliable results with a combination of polyimide tape precisely cut and aligned with protective oil. Next, we used a combination of epoxy and protective oil to protect the exposed surfaces. Finally, the snap dome was to be activated by the edge of a PCB, which is an atypical usage. We modified the metal dome switch so that it did not have its contact point fully encased in the diameter of the switch. By making this modification, we were able to accomplish multiple activations without false or missed contacts.
Benefits: Because of the thoughtful selection of materials and “out of box” thinking in design, Flexible Circuit was able to create a device that met the heat, humidity and drop tests required by our customer.
Two Sided Die Cut Window
Hard Gold Plating
Challenge: Produce a circuit with a very tight trace & space requirements with portions exposed on both sides of the circuit, unsupported traces in effect. The traces were specified at .0025” and the spaces at .005”.
Solution: We knew the unsupported traces would be damaged if we utilized typical design, manufacturing and packaging processes. After careful consideration, we designed a removable protective shield to stabilize the circuit during the manufacturing process. In addition, we packaged each of the circuits individually. While both of these solutions added cost, they were necessary for the success of our customer’s program.
Benefits: By partnering with our customer’s design and quality teams from the early stages of development, the dividends realized were great. Production yields improved from 15% during the test stages to more than 90% after full implementation. Together we figured out how to mass manufacture a circuit that seemed impossible in its early stages.