The Alloy Chart shows a list of the solder alloys that are available from Kester. Sn63Pb37 and Sn60Pb40 are standard alloys. Other alloys are available as special order items.
Pressure from marketing and legislation in both Europe and Asia have forced electronics manufacturers to
move away from lead-based solders. Typical lead-free alloys contain 3-4% silver, which can be costly.
In addition to cost concerns, typical Tin/Silver/Copper (or SAC) alloys also present issues with increased
dissolution of Copper from boards and components during the soldering process. As an example, SAC305,
one of the industry's most popular lead-free wave soldering alloys, is known to dissolve Copper at a rate
more than twice as fast as Sn63Pb37.
In response to demand for a low cost and low copper dissolution alloy, Kester has developed Ultrapure®
K100LD. Kester K100LD is a eutectic Tin/Copper alloy with controlled metallic dopants to control the grain
structure within the solder joint, and to minimize the dissolution of copper into the solder pot. K100LD
virtually eliminates the occurrence of common defects such as icicling and bridging. The improved grain
structure also results in shinier solder joints than traditional lead-free alloy alternatives.
Lead-free wave soldering processes tend to produce a greater amount of dross than traditional leaded
processes. For this reason, Kester produces all lead-free bar solder products with anti-drossing technology
to improve process control and to allow the user to get the most value for the money with minimal maintenance
costs. Kester Ultrapure® SAC305 Bar Solder was designed to minimize the amount of dross generated in a
wave soldering, selective soldering or dip soldering process. Kester Ultrapure® SAC305 is manufactured
with virgin metals which meet the high standards of Kester Ultrapure® line of bar solders.
For soldering applications which require maximum reliability of solder joints, especially for surface mounted
components, only solder of the highest purity is acceptable. Kester does not make any vague claims of
outstanding solder purity. Complete analysis of Kester Ultrapure® Bar Solders prove that every batch conforms
to the strictest quality control standards in the solder industry.