Survey on Lead Free Solder Systems

1 Foreword

This report covers an overview of the results achieved within the national Danish Lead Free Soldering project. The project has had the aim of comparing electronics joining technologies based on lead free alloys with traditional SnPb-solders. The report describes the environmental aspects of introducing lead free solder systems in electronics manufacture compared with lead containing solder. It also contains a technical assessment of two promising lead free solder systems (Sn-4.0Ag-0.5Cu and Sn-3.5Ag). Experiments have been carried out on FR4 PCBs using both reflow soldering and wave soldering techniques.

The project aims to describe the environmental aspects of the electronics industry’s transition from traditional lead-rich solder to lead-free solders for bonding components to printed circuit boards. The project is funded by a grant from the Danish Environmental Protection Agency, from which Henri Heron was supervising the project.

Party to the project are Technoconsult (project leader), DELTA Danish Electronics, Light and Acoustics, Grundfos, HYTEK, SIMRAD and Bang & Olufsen. The Danish Toxicology Centre was subcontracted to make the toxicological evaluation of the solders and fluxes.

The project partners want to thank Teleinstrument (Alpha-Fry Technologies) and CYNCRONA (Multicore) for providing the solders used in the project. Furthermore we appreciate the cooperation with another Danish project organised under the auspices of SPM with whom we shared the test printed circuit boards.

Copenhagen 2002-11-20

Poul Juul, HYTEK
Kim Zachariassen, DELTA
Turi Roslund, Bang & Olufsen A/S
Svend Aage Hansen, Bang & Olufsen A/S
Lars Ebdrup, Grundfos Electronics A/S
Brian Sloth Bentzen, SIMRAD AS
Ivan Ring Nielsen, TechnoData A/S