Vectronics VEC-1500K - Manual (Page 9)

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circuits and where joint contraction might move tiny surface-mount parts out of
position during cooling. As a rule, however, either type may be used
interchangeably for most bench applications.
Specialty Solders: In addition to the popular 60/40 and 63/37 alloys,
electronics distributors now offer a variety of specialty solders. Specialty
solders have unique properties that are well matched to specific electronic
applications. Here are some of the more popular types:
2% Silver Solder: This lead/tin/silver alloy provides a somewhat higher melting
point, improved conductivity, and increased strength over 60/40 and 63/37
solders. The 2% alloy works well where added joint durability is needed, or in
applications where high operating temperatures and strong electrical currents
may work together to melt conventional solders.
Low-Temperature Solder: This alloy melts at a significantly lower temperature
than 63/37 or 60/40, reducing the risk of thermal damage to unusually heat-
sensitive electronic components. The most popular low-temp formula combines
a mix of 43% tin, 43% lead, and 14% bismuth into an alloy that melts at 295-325
degrees F. Some low-temperature solders are highly toxic, so be sure to read
instructions carefully before using them.
Lead-free Solder: Lead is a toxic substance that accumulates in the body.
Because of this, leaded solders can't be used in some applications or handled by
people who are medically at-risk for lead contamination. As an alternative,
Tin/antimony solder alloys provide a low-toxicity bond for electronic
applications where environmental protection or medical safety is important. A
tin/silver alloy may also fulfill this requirement.
Commonly Available Forms of Solder
Wire solder comes in a variety of standard diameters and core configurations.
Most have one or more hollow cores filled with flux. Flux is an essential
chemical agent used to free metal surfaces of oxides during heating. Dispensing
flux via a hollow core in the solder wire controls the delivery rate and ensures
uniform flux dispersion over the connection.
Solder Wire Size: Standard wire diameters for solder range from a thick .125-
inch (11 gauge) wire to a hair-fine .010-inch (31 gauge) wire. Here is a list of
standard solder diameters shown:
Diameter Gauge
.125" 11
.093" 13
.062" 16
Diameter Gauge