Thermomechanical Reliability of Lead Free Solder Joint in SMT Assembly

Author

J. Sandera

Author_Institution

Brno University of Technology, Faculty of Electrical Engineering and Communication, Department of Microelectronics, Udolni 53, 602 00, Brno, Czech Republic. Phone: +420 541 146 151, fax: +420 541 146 298, E-mail: sandera@feec.vutbr.cz

fYear

2007

fDate

5/1/2007 12:00:00 AM

Firstpage

123

Lastpage

127

Abstract

This conference paper focuses on the practical measurement of the reliability of the LF solder connection SMT mounted components on PCB. For measuring of the reliability a special printed boards with various footprints and Sn -HAL, immerse Sn and galvanic Au surface finishing were designed. Printed boards with vapour and wave soldered components underwent temperature cycling and failures (cracks) were evaluated. A temperature cycling +100deg C/0degC without dwell was applied. The electrical connection was measured continuously during the entire thermomechanical loading. This was done by connecting of a powered LED diode parallel to the examined solder joint. There was original equipment designed for the temperature cycling. The Peltier semiconductor cells were used for cooling and heating of the copper plate. On this plate the printed boards with components were placed. This solution had a low temperature capacity and it enabled relatively short temperature cycles.

Keywords

"Thermomechanical processes","Environmentally friendly manufacturing techniques","Lead","Soldering","Surface-mount technology","Assembly","Temperature","Tin","Galvanizing","Gold"

Publisher

ieee

Conference_Titel

Electronics Technology, 30th International Spring Seminar on

ISSN

2161-2528

Print_ISBN

978-1-4244-1217-4

Electronic_ISBN

2161-2064

Type

conf

DOI

10.1109/ISSE.2007.4432832

Filename

4432832