User:Laurasmithhp/Solder Wire

Solder wire is a metal alloy used to join metallic surfaces in the soldering process.

Overview
Solder wire is made in various diameters and supplied on spools sized by weight. Common weights are 250 g and 500 g. It is flexible and can be easily cut to length. It can be either solid or contain a core of flux material. Solder wire is commonly used for electronic circuit boards in the electronics manufacturing industry.

Flux-core solder is the most common, containing a core of flux that releases as the solder is melted onto the joint. Flux is a chemical cleaning agent that removes oxidation from the metals being joined. It also seals out air and improves the wetting characteristics of the liquid solder.

Only rosin core solder wire is suitable for electronics work. Acid-core solder cannot be used for electronics work because it will destroy the electronic components, erode the component leads, and form a conductive layer leading to shorts.

Diameters can range from .001” (0.025mm) diameter to .250” (6.35mm) and larger. The dimensions possible are subject to the properties of each metal.

Advantages
A flux-cored solder wire advantage is the ease with which the solder can be applied with the flux. It is much more convenient than using solid solder wire and then applying the flux in a separate application.

Solder wire can be manufactured to the specifications of a particular job. That means for surface-mount technology (SMT) in electrical manufacturing, the solder wire will contain the right material flux and the solder itself will be the right alloy and diameter depending on the work involved.

Solder wire can either be manufactured in small quantities for research and evaluation or in full-scale production volumes.

Solid solder wire is available if liquid flux is being used separately.

Disadvantages
Solder wire made with rosin can be a disadvantage because rosin is a known allergen. Rosin-free cored wire solders have been developed for this reason and because of the push to develop more environmentally friendly products.

Soldering with rosin core fluxes can leave a residue that leads to cold solder joints. If liquid flux is used the solder flows completely over the joint. This quicker soldering means less likelihood of melting ties.

Available Materials
Solder wire can be made from over 100 alloys, including pure indium and indium alloys, lead-free alloys, gold/tin, tin/lead and bismuth alloys as well as many other combinations. The melting points range from 47*C (117*F) to over 364*C (687*F).

Storage
Solder wire shelf life is contingent upon the alloy and its resistance to oxidation. The storage container and the conditions in which it is stored also impact solder wire shelf life. To extend storage time, surface oxidation needs to be kept to a minimum. Store the solder wire in a tightly closed container at temperatures below 22°C, and in 55% relative humidity (RH). Inert atmosphere, such as a nitrogen dry box can also be used to store solder wire.