Thermophysical measurements over PCBs, as a complex element in the lead-free assembling process

M. Branzei1, I. Plotog1, P. Svasta1, M. Miculescu1 and J. Villain2

1POLITEHNICA University of Bucharest, Romania
2University of Applied Sciences Augsburg, Germany

Keywords: lead-free assembling process
property: diffusivity
material: PCB substrate

In the surface mounted technology (SMT) the PCBs are used in assembling process as support for electronic components interconnection structures. The process result are PCBs and the elements of these structures are electronic components terminals, solder joints and pads - the dedicated metallic surface on PCB - as support for interconnection structures. For the pads, were considered two major elements, the metallic surface, characterized by geometry and finishes (ImmAu; Chemical Sn; HASL; OSP; ImmAg; Cu), respectively the substrate, with contribution over thermal mass and thermal transfer, consisting of different type of PCBs having different core materials (FR4, ceramics, glass, metals, polymers) and geometry[1]. Therefore the solder joints can be considered result of a complex function of "4P" Soldering Model[2] whose dynamic elements, Pad-Paste-Pin-Process have synergistically interactions and correlations. So, the PCBs can be considered a complex element in the Lead-Free assembling process, which is defined in the design stage as a function of the pad finishes, geometry and substrate. Each of the particular solution defined will have unique values of thermophysical properties(THP). In the paper it will be presented the results of the THP for different types of PCBs having particular solutions defined by the pad finishes, geometry and substrate[3].

  1. I. Plotog, G. Varzaru, C. Turcu, T.C. Cucu, P. Svasta, N.D. Codreanu ESTC 2008: Vol. 1, 2, Proceedings, pp. 121-124, London 2008

  2. P. Svasta, I. Plotog, T. Cucu, A. Vasile, A. Marin ISSE 2009,The 32nd International Spring Seminar on Electronics Technology, 13-17 May, Brno, Czech Republic proceedings ISBN 978-80-214-3874-3.

  3. M. Branzei, P. Svasta, F. Miculescu, M. Miculescu, I. Plotog SIITME 2009, The 15th International Symposium for Design and Technology of Electronics Packages, 17-20 Sep 2009, Gyula, Hungary, Conference proceedings, pp. 129-133.

     Official Sponsors

uni Anter_logo Tziolas_logo_ linseis netzsch