Semi-flex PCBs use specialized FR-4 materials and a specific manufacturing method to create a flex-to-install design that can provide an economical solution for certain applications. Semi-flex PCBs often can function as a more than adequate solution for certain more advanced applications, while manufacturing is less complicated. Often, it’s a way that combines the best of both worlds. You can bend the board one time to fit the finished product, while not complicating things unnecessarily by laying on a higher level of technology than necessary.