How to Manage Wave Solder Alloy Contaminations
European electronics industry is soldering with lead-free alloys for one decade now. In this period not only the knowledge of the alloys in the assembly process has been improved,but also a high amount of data is collected. Technology has changed over these ten years including the prices of the metal. The dramatic increase of operation costs due to high metal prices forces engineers to look more critical to their wave soldering process. Balver Zinn has been studying the consistency of alloys in wave soldering process since the implementation of lead-free. The lab measures the contamination of lead-free solder alloy samples of their costumers and thus enables them to do statistical process control on the alloy composition. In these ten years of lead-free soldering over 25.000 samples were investigated looking at contaminations of lead,the drift of the Copper content,and or increase of iron in the alloy due to solder pot erosion. Analyzing this data returns a lot of information on copper leaching for the different alloys. How to manage the copper level in the lead-free solder alloy to avoid an increase of soldering defects will be discussed. The data of these alloy analysis contains samples of all kind of production environments: low and high volumes,different solder machines and solder pot contents,solder temperatures,alloys,board finishes and inert systems versus soldering in air. With this presentation we try to give guidelines for the costumers how to control their alloy in order to minimize solder defects in combination with keeping the metal consumption/operational cost as low as possible.