Print parameter effects on thermal conductivity of 3D-printed heat sinks for LED system applications

Abstract

Effective thermal management in LED systems is critical for maintaining luminous flux, spectral stability, and operational lifetime. While traditional manufacturing limits material and geometric flexibility, 3D printing allows the fabrication of complex, lightweight heat sinks tailored for enhanced dissipation. To drive adoption, the community must first establish 3D printing guidelines linking printing parameters to thermal performance. This study investigated the effects of layer height and extrusion multiplier on the relative thermal conductivity of a fused filament fabrication (FFF)-printed component made from a thermally conductive Thermoplastic Polyurethane (TPU) polymer. Experimental samples were 3D-printed under selected print parameter settings, and thermal conductivity was determined from the controlled-temperature response. Results showed that FFF parameters significantly affected in-plane-direction heat transfer. Layer heights ≤75% of the 1.0 mm nozzle diameter resulted in decreases of 10% to ~40% in print-direction thermal conductivity. In addition, increasing the extrusion multiplier from 0.9 to 1.1 progressively improved thermal conductivity, with a 5-10% increase near 1.0 yielding a ~45-75% increase. The study results indicated that selecting layer height and extrusion multiplier can be used to minimize internal thermal resistance, providing optimized 3D-printed heat sinks for LED thermal management systems.