Lead-Free Soldering Risks and Reliability Problems in Space Electronics

Some elements can be extremely harmful for both environment and human health. If it is not possible to avoid them completely, they must remain at least within the certain limits. This situation is more common especially in electrical and electronic manufacturing due to the usage of leaded alloys in solders and finishes. In this case, European Community, United States, Japan and some other countries have at least approved the use of these chemicals within the maximum limits defined by RoHS (Restriction of the Use of Hazardous Substances) Directives which is 0.1% ppm for lead. RoHS rules came up in the early 2000s became mandatory in Europe, United States and Japan in the field of commercial electronics in the last half of next decade. Manufacturers switched to lead-free solder and component production and usage rapidly as a result of this situation. This rapid transition has brought many question marks and information gaps. Certain industries such as military, aerospace, transportation and space are excluded from RoHS Directives. However, switching of electronic component manufacturer to lead-free technology brings some problems such as finding leaded components and reduced number of leaded product supplier in time for space and similar industries. Reliability is one of the most important and critical factor in space technologies. Lead-free solder alloys and technologies has different properties compared to leaded alloys in terms of process to material. Leaded alloys are highly reliable and traceable compared to lead-free alloys. Reliability level of lead-free alloys should be defined by destructive, non-destructive, accelerated tests and inspections and also a lead-free plan should be prepared if lead-free solder alloys are planning to be used in space technologies.