| Summary: | This article investigates the optimum number of hexagonal boron nitride (hBN) layers for the heat spreading application. The multilayer hBN films (up to 12L) are obtained by multiple wet transfers of monolayer hBN onto the Pt/Cu/Ti coil. The thickening of the hBN layer on the coil is verified based on optical microscopy images. Three figures of merit (FoM) are introduced, FoM 1 for the hotspot during transient-state (TS) Joule heating, FoM 2 for the hotspot during steady-state (SS) Joule heating, and FoM 3 for the lateral thermal resistance, T also during the SS Joule heating. Based on the TS Joule heating analysis, 6L hBN was optimum for the hotspot reduction with FoM 1 of -22%. Based on the SS Joule heating, 7L hBN was optimum for the hotspot reduction with FoM 2 of -18.5%. The reduction in T during the SS Joule heating is acceptably good when wet transferred hBN thickened up to 5L with FoM 3 of -35.4%.
|
|---|