Surface temperature of electronic assemblies equipped with tilted and low-powered QFN64 subjected to free convection

Abstract

Purpose This work deals with the case of the quad flat non-lead 64 (QFN64) electronic package generating a low power range ranging from 0.01 to 0.1W. It is installed on one side of a printed circuit board (PCB) that can be inclined relative to the horizontal plane with an angle varying between 0° and 90° (horizontal and vertical positions, respectively). The surface temperature of the electronic assembly is subjected to air natural convection. Design/methodology/approach Calculations are done by means of the finite volume method for many configurations obtained by varying the generated power and the inclination angle. Findings The distribution of the surface temperature is determined on all the assembly areas (QFN and PCB). The study shows that the thermal behaviour of the electronic device is influenced by the generated power and the inclination angle. The 3D numerical survey leads to correlations allowing calculation of the average surface temperature in any part of the assembly, according to the power generated by the QFN64 and the inclination angle. Originality/value The proposed accurate correlations are original and unpublished. They optimize the thermal design of the electronic QFN64 package, which is increasingly used in many engineering fields.

Numerical and experimental study of free convection on wire-bonded QFN64b electronic package

“…The survey shows that the radiative heat transfer is negligible given the low surface emissivity and the temperatures reached by the assembly. This work also complements a recent study of Baïri et al (2017) dealing with the same assembly equipped with QFN64 basic model. The study also confirms that the wire-bonding technique reduces the QFN temperature by enhancing the pure conduction phenomena QFN-PCB.…”

“…The surface temperature difference is of about 1.5K on (Q T ) and 3K on (Q S ) when P increases from 0 (power-off) to the maximal value P = 0.1 W. The evolution of D T versus P is not linear on the QFN, showing that the conductive thermal resistance is not constant in the considered power range, in contrast to what was observed for the PCB. These results were compared with those obtained for the basic version of this device, the QFN64, which was discussed by Baïri et al (2017). The trends are the same for both models with and without bondings.…”

Numerical heat flow visualization analysis on enhanced thermal processing for various shapes of containers during thermal convection

“…subjected to various thermal boundary conditions of the walls. A number of works (Moukalled et al , 1993; Bairi et al , 2010; Moukalled and Darwish, 2010; Bairi, 2011; Bairi et al , 2012; Moukalled and Darwish, 2013; Bairi et al , 2017) are based on natural convection in parallelogrammic/rhombic containers. A few works are detailed as follows.…”

“…Moukalled and Darwish (2013) carried out numerical investigation to analyze the double diffusive natural convection in porous rhombic annulus and it was found that the mass and heat transfer rates increase with Prandtl and Rayleigh numbers. Bairi et al (2017) studied the cooling of electronic package (QFN64) on a printed circuit board via free convection by varying the inclination angle. It was found that the inclination angle influences the cooling of QFN64.…”