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Article
Publication date: 5 June 2017

Abderrahmane Baïri, Nacim Alilat, Ali Hocine, Abderrezak Hamouda and Oriana Haddad

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…

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.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

To view the access options for this content please click here
Article
Publication date: 5 June 2017

Abderrahmane Baïri, Clara Ortega Hermoso, David San Martén Ortega, Iken Baïri and Zsolt Peter

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…

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.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

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