Inorganic Stabilizer Introduced Flux System with High Tackiness: an Efficient and Novel Material Solution for the Micro LED Mass Transfer

As Micro LED technology becomes increasingly matured, several assembly process options were proposed, and seems feasible and reliable to be used in mass production. Usually, these processes require a tacky flux to adhere the die to the substrate when mass transferring, and meanwhile to provide certain activation to facilitate the joining process. However, the work life of such flux is limited, which leads to low printing efficiency and unstable assembly quality. In this work, a novel inorganic compound stabilized tacky flux system was successfully developed for newly emerging carrier assistant Micro LED mass transfer technology. This designation can extend the working life from less than 30 mins to more than 180 mins. Such a significant improvement in working life was realized by introducing an inorganic stabilizer, which reacted with chemicals to strengthen the inner connection, furtherly realized precise and efficient tackiness in-situ controlling. Moreover, this tacky flux system didn't make any compromising on flux's inherent characteristic of promoting soldering. Inorganic compound stabilized tacky flux provided a new approach for material solutions in Micro LED mass transfer.