Effects of the Encapsulating Resin on the Junction Temperature of the QFN16 and QFN32 Electronic Packages Subjected to Free Convection

Abderrahmane Baïri, Oriana Haddad, Jean-Pascal Guinart, Kemi Adeyeye, Nacim Alilat

Research output: Contribution to journalArticle

1 Citation (Scopus)


The junction temperature of the quad flat no-lead with 16 and 32 leads (QFN16 and QFN32) electronic packages subjected to free convection is highly affected by their encapsulating resin’s thermal conductivity.
This study considers a variation of this conductivity between −80% and +100% of the average value measured on an industrial prototype by means of the Transient Plane Source method. The three dimensional numerical solution based on the control volume formulation shows that the thermal trend is of exponential type for these components but with different functions.
The proposed relationships allow the calculation of the junction temperature of bothQFN16 andQFN32 according to the power generated varying between 0.1 and 1W, and the inclinations relative to the horizontal plane in the range 0–90° (horizontal and vertical positions respectively). The law governing the influence of conductivity on the junction temperature shows that a more conductive resin does not significantly lower the junction temperature.However, for low conductivity values, the temperature can exceed the maximum recommended by the manufacturers, causing possible malfunction of theQFN and altering
its technical performance that are directly related to its thermal state. In some cases, the device can be decommissioned.
Original languageEnglish
Pages (from-to)353-358
Number of pages7
JournalHeat Transfer Engineering
Issue number4
Early online date7 Jun 2017
Publication statusPublished - 16 Jan 2018



  • Home automation
  • home security control
  • home temperature control
  • Smart systems
  • Numerical analysis
  • QFN64
  • electronic assembly

ASJC Scopus subject areas

  • Numerical Analysis
  • Architecture
  • Building and Construction

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