Thermal design of tilted electronic assembly with active QFN16 package subjected to natural convection

The natural convective heat transfer coefficient detailed in this study deals with the five elements of a typical assembly used in electronics constituted by a Printed Circuit Board (PCB) on which a quad flat non-lead (QFN16) is welded. This active package can be placed in different positions on the board and generates during its actual functioning a power ranging between 0.1 W and 0.8 W. Many configurations of the assembly are considered, corresponding to seven inclination angles of the PCB varying between the horizontal and vertical positions. Correlations between the average convective heat transfer coefficient, the generated power and the PCB inclination angle are proposed for the five assembly parts. They allow to optimize the thermal control of electronic devices incorporating QFN16 packages, which are increasingly used in engineering.