Technical
Tin Reflow And Tin Lead Reflow
Tin Reflow
Reflowed tin is a process that results in improved solderability as opposed to standard electroplated tin. After a part has been electroplated with tin, the part is reheated above the melting point of the tin plating (greater than 450°F), then cooled.
Reduces The Internal Stresses Of Electroplating
Tin reflowing reduces the internal stresses that arise during the electroplating process that have been proven to contribute to tin whisker formation.
Circuit Boards & Metallic Sheets
In the case of circuit board components, parts that have been reflowed also require less insertion force. Additionally, metallic strips or sheets that have been plated with tin and reflowed can later be stamped into complex part shapes because of the excellent formability and ductility of the tin.
Reflowed Tin Plating Is Lead Free
One of the major benefits of reflowed tin plating is that unlike solder plating, reflowed tin is lead free. As many industries are looking to remove lead from their products because of its health and environmental issues, reflowed tin is an attractive option.
ROHS Compliant
Reflowed tin is compliant with ROHS standards that govern the use of hazardous products in electronic products.
An Uncommon Process
There are very few companies capable of reflowing tin. Associated Plating is NADCAP approved and one of the few companies in the United States that can perform reflowed tin plating for your application. We are the experts; we have performed tin reflow and tin / lead reflow for over 30 years.
Tin Lead Plating
Tin Lead plating consists of the co-deposition of a layer of tin and lead onto a base part. Wide varieties of tin-lead alloy compositions are used depending on the application and desired properties of the final product.
Tin Lead Plating Advantages For The Electronics Industry
The electronics industry uses tin/lead because:
Tin lead melts at low temperatures.
Tin lead can be soldered easily by a wide variety of methods.
The alloys are relatively corrosion resistant.
The alloys are good electrical conductors.
The alloys are ductile and are not harmed by subsequent operations such as stamping.
The presence of lead prevents the formation of tin whiskers.
Tin lead can be reflowed to further improve shelf life and most other properties.
60/40 & 90/10 Tin/Lead Alloys
Associated Plating is NADCAP approved and offers 60/40 and 90/10 Tin/Lead alloys in either matte or reflowed form, ensuring the highest quality results.
Additional information regarding tin whiskers, pure tin and tin lead:
https://nepp.nasa.gov/WHISKER/background/
https://nepp.nasa.gov/npsl/Prohibited/tin_prohibition.htm
http://www.te.com/documentation/whitepapers/pdf/Keeping_Tin_Solderable.pdf
