A Sharp Phase Transition Polymer for High Spatial Selectivity in Microtransfer Printing

Microtransfer printing (MTP) is an advanced processing technology for flexible electronics manufacturing and heterogeneous integration. As device integration continues to increase, optimizing spatial utilization has become a significant challenge in MTP. In this work, we propose using a reversible, sharp phase transition polymer (SPTP) to enhance the spatial resolution of MTP. In situ characterizations reveal that the SPTP exhibits a pronounced modulus change within a narrow temperature window, corresponding to a distinct phase boundary. This sharp transition enables precise thermal control of adhesion. Dynamic adhesion force measurements further confirm the material's large adhesion switchability. Leveraging these properties, the SPTP stamp achieves high-resolution selective transfer with a chip spacing of 10 μm. These unique properties of the SPTP provide the material basis for achieving high spatial resolution selective transfer.