Flexible PCB Technology has evolved enormously due to the development of mobile and smart devices and is experiencing another huge change due to the evolution of wearable device technology such as smartwatches, smart rings, various wearable health sensors, Bluetooth earphones, smart IC cards, and others. For wearable devices, very thin film PCBs with several 10s um thickness are used and are very flexible and not easy to handle each unit. Individual film PCB is easily bent and rolled over. So, for conventional SMT lines, the individual unit separated from roll-to-roll film PCBs is needed for production processes or transportation between lines or factories and needs special holding jigs for process handling. To overcome these issues, innovative full-automatic roll-to-roll laser SMT (Film LMT) Technology is proposed for flexible film PCB processes. This new film LMT technology has many advantages, such as a compact footprint, simple process, no need for trays, low-cost production, easy adoption of laser selective reflow (LSR), no limitation on material length, easy customization, and others. Its core technologies include a thin-film PCB handling function using a roll-to-roll device, the warpage-free laser selective reflow technology with localized heating, the minimum heat accumulation in the bonding area, and others. In this presentation, this new film LMT technology and its test results are introduced and discussed.
