Flexible and stretchable Micro-LED array devices with Optical-Thermal layered packaging

Flexible and stretchable micro-LED arrays suffer from severe heat accumulation at high current densities. Conventional thermally conductive fillers can also inhibit curing of silicone matrices. We propose a platinum-catalyst-modified optical-thermal layered packaging structure to address both problems. A 4 × 4 flexible and stretchable LED array was fabricated. It integrates a heat-dissipating and light-reflecting substrate layer. The middle layer contains an LED array with serpentine conductive interconnects. A light-transmitting functional layer forms the top layer. AlN particles were used as thermally conductive fillers in the substrate. Additional platinum catalyst was introduced as a curing compensator. Uniform dispersion and complete curing were achieved at 20 wt% loading and 60 μm particle size. The composite substrate showed favorable thermal and mechanical properties. Its thermal conductivity reached 0.222 W/(m·K), 35.4% higher than pristine Ecoflex 00-30. It remained structurally intact under 300% tensile strain. The flexible substrate and serpentine interconnects effectively released stress during mechanical deformation. They maintained reliable electrical connections under dynamic bending. Transient thermal resistance tests were conducted at a constant driving current of 20 mA. The steady-state junction temperature was 2.95 °C lower than that of pristine Ecoflex 00-30 packaging. These results demonstrate effective thermal management while maintaining mechanical compliance.