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

Abstract

Purpose The wire-bonded version of the quad flat non-lead with 64 leads (QFN64b) is increasingly integrated in modern arrangements, given its thermal and electrical characteristics suited for specific applications. Temperature control is thus essential for its proper operation, particularly when the heat exchange with the environment is done by natural convection. This work aims to consider a conventional assembly consisting of a large printed circuit board (PCB) on which is welded a QFN64b generating a power in the range 0.01-0.1 W. The PCB could be inclined at an angle varying between 0° and 90° (horizontal and vertical positions, respectively) according to the intended application. Design/methodology/approach The 3D numerical approach done by means of the finite volume method is complemented by thermal and electrical measurements for all the configurations numerically processed. The low deviations obtained between the calculations and the measurements validate the adopted model. These results complement recent work that considers the same assembly equipped with a tilted and low-powered QFN64 basic model subjected to free convection. Findings The surface temperature in any part of the assembly has been determined. The influence of the power generated by the device and the PCB’s inclination angle relative to the gravity field have been quantified. The work shows that the radiative heat transfer is negligible given the temperatures reached and that the thermal state of the considered assembly is different from the one equipped with the QFN64 basic model. The QFN’s temperature is lowered, while that of the PCB is increased. The temperature distribution is also different from that of assemblies equipped with other QFN models with and without wire-bonding. Originality/value The correlations proposed in this survey help optimize the thermal design of the QFN64b electronic package used in many engineering fields.

Numerical investigation of nanofluid particle migration and convective heat transfer in microchannels using an Eulerian–Lagrangian approach

“…Recent advances stemming from the fields of miniaturized electronics (Dixit & Ghosh 2015; Baïri et al. 2017) and densely packed photovoltaics (Fernández et al. 2018; Sharaf & Orhan 2018) have generated the need for high heat removal rates in heat exchangers and heat sinks, which could be based on natural convection (Haddad et al.…”

“…Recent advances stemming from the fields of miniaturized electronics (Dixit & Ghosh 2015;Baïri et al 2017) and densely packed photovoltaics (Fernández et al 2018;Sharaf & Orhan 2018) have generated the need for high heat removal rates in heat exchangers and heat sinks, which could be based on natural convection (Haddad et al 2017;Baïri 2018a;Baïri, Laraqi & Adeyeye 2018) or forced convection (Kewalramani, Agrawal & Saha 2017;Jing et al 2018;Li et al 2018) heat transfer. Convective cooling techniques are designed such that device temperatures remain below material and reliability limits (Liang & Mudawar 2019).…”