Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
647300 | Applied Thermal Engineering | 2013 | 6 Pages |
Heat transfer is crucial to the fabrication of high efficiency light emitting diode (LED) packages. The effectiveness of the heat transfer depends on the package materials and design. This paper presents an application of high thermal conductivity aluminum nitride (AlN) films to replace low thermal conductivity epoxy resin or alumina substrates. The AlN film was directly deposited on an aluminum plate which enabled the removal of thermal interface materials (TIM) such as the adhesive thermal bonding sheets that are used in conventional metal printed circuit board (PCB)-based LED packaging process. A fully dense AlN ceramic film was successfully deposited at room temperature using the aerosol deposition method. The thermal resistance, a parameter of the heat transfer characteristic of an LED package, was measured using a thermal transient tester. The results showed that the thermal resistance of the LED package mounted on the AlN thick film was 28.5 K/W, while an LED package mounted on a conventional epoxy-based metal PCB and a PCB with thermal vias were 47.2 K/W and 36.5 K/W, respectively. This indicates that an aerosol-deposited AlN-based LED package exhibits greatly enhanced heat transfer compared to the conventional metal PCB.
► Aluminum nitride (AlN) film was deposited on aluminum metal substrate. ► Dense AlN film was formed at room temperature by the aerosol deposition method. ► Higher thermal conductivity was obtained at the AlN film, over 88 W/m·K. ► Heat transfer property of an LED Package was measured by a thermal transient tester. ► LED package with AlN film exhibited lower thermal resistance compared with the conventional FR-4-based PCB and Al2O3 film.