Product Description

Solder is a fusible metal alloy used to join together metal work pieces and having a melting point below that
of the work piece.Soft solder is what is most often thought of when solder or soldering is mentioned and it
typically has a melting range of *0 to **0 °C (**0 to **0 °F). It is commonly used in electronics and
plumbing. Alloys that melt between **0 and **0 °C (**0 and **0 °F) are the most commonly used. By
definition, using alloys with melting point above **0 °C (**0 °F) is called 'hard soldering', 'silver soldering'
or brazing. Soft solder can contain lead and/or flux but in many applications lead free solder is used.
Perhaps the most common and most familiar form of solder is as a wire or rod, though plumbers often use
bars of solder while jewelers often use solder in thin sheets which they cut into snippets. Solder can also
come in a paste or as a preformed foil shaped to match the workpiece. The word solder comes from the
Middle English word soudur, via Old French solduree and soulder, from the Latin solidare, meaning "to
make solid".Eutectic alloys melt at a single temperature. Non-eutectic alloys have markedly different solidus
and liquidus temperature, and within that range they exist as a paste of solid particles in a melt of the
lower-melting phase. The pasty state causes some problems during handling; it can however be exploited
as it allows molding of the solder during cooling, e.g. for ensuring watertight joint of pipes, resulting in a so
called 'wiped joint'.
With the reduction of the size of circuit board features, the size of interconnect shrinks as well. Current
densities above **4 A/cm2 are often achieved andelectromigration becomes a concern. At such current
densities the Sn*3Pb*7 solder balls form hillocks on the anode side and voids on the cathode side; the
increased content of lead on the anode side suggests lead is the primary migrating species.
Contact with molten solder can cause 'solder embrittlement' of the materials, a type of liquid metal
embrittlement.