Research on root cause of tin whiskering and quantification by standard test
Matte tin tends to become one of the preferred platings of the future. However, tin surfaces showed increased whiskering and insufficient knowledge is available on the root cause and main influence factors of whisker formation. As long whiskers can even cause short cuts, this is a road block for introduction of lead-free platings. Understanding the root cause on tin and other surfaces allows es-tablishment of a standard test for reliable quantification and control of whiskering.
Information labelling system (ILS) for lead-free printed wiring boards
Global standardisation of soldering materials is not to be expected within the next years. This was learnt during the discussions with the inter-regional partners. A variety of materials will thus substitute tin-lead. Repairs require solders that are compatible with the soldering materials on the board. In recycling, lead-free solders and platings on PWBs enable material specific treatment to increase profit and material recovery. An information labelling system (ILS) about soldering materials can solve these problems. It should at least store information about soldering materials used in manufacturing of the PWB. Stored information to differentiate appliances categories and features characterised in the WEEE contributes to implementation of WEEE, e. g. to decide between old appliances and old-old appliances that are subject to different treatment rules. The tool can also give feedback from repair and recycling about failures of certain soldering material combinations. Thus, an ILS facilitates statistic reliability investigations for manufacturers, or gives information about thermal stress which influences remaining life time of components for reuse.
Matte tin tends to become one of the preferred platings of the future. However, tin surfaces showed increased whiskering and insufficient knowledge is available on the root cause and main influence factors of whisker formation. As long whiskers can even cause short cuts, this is a road block for introduction of lead-free platings. Understanding the root cause on tin and other surfaces allows es-tablishment of a standard test for reliable quantification and control of whiskering.
Information labelling system (ILS) for lead-free printed wiring boards
Global standardisation of soldering materials is not to be expected within the next years. This was learnt during the discussions with the inter-regional partners. A variety of materials will thus substitute tin-lead. Repairs require solders that are compatible with the soldering materials on the board. In recycling, lead-free solders and platings on PWBs enable material specific treatment to increase profit and material recovery. An information labelling system (ILS) about soldering materials can solve these problems. It should at least store information about soldering materials used in manufacturing of the PWB. Stored information to differentiate appliances categories and features characterised in the WEEE contributes to implementation of WEEE, e. g. to decide between old appliances and old-old appliances that are subject to different treatment rules. The tool can also give feedback from repair and recycling about failures of certain soldering material combinations. Thus, an ILS facilitates statistic reliability investigations for manufacturers, or gives information about thermal stress which influences remaining life time of components for reuse.
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This document reflects the status of the research on root causes of tin whiskering. It explains the hypothesis and evidence of whisker growth and why whiskers can be prevented by short time storage at higher temperatures. -
Marking of lead-free (Pb-free) components and assemblies
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Version for print