Tin is a soft, ductile, and malleable silver-white metal. Tin can be moulded and stretched into a variety of shapes without splitting because of its elasticity. Tin is also non-toxic, conductive, and corrosion resistant, which makes it popular in the food processing, electronics, and shipping industries. Tinning, also known as “Tin Plating,” is an ancient art form. This article will go through current and prospective applications of tin plating, as well as the coating’s strengths and drawbacks, best practices in tin plating and some more information on the same.
Industries that use Tin Plating
Among other things, tin plating is commonly used in electronics, mechatronics, hardware, fasteners, culinary equipment, and, more recently, solar panels. Devices and components used in aviation, electrical panels and wire connections utilised in the creation of new residences and buildings, and screws, nuts, and bolts utilised in marine hardware are some examples found in the technology sector.
Advantages of Tin Plating
Tin has a number of advantages that make it a good choice for corrosion resistance:
- “Fretting”, that refers to surface-to-surface corrosion.
- Environmental, which refers to tin tarnish caused by sulfur-rich surroundings.
- Excellent solderability and good contact resistance.
- Mirror like aesthetic.
- The ability to choose between matte tin plating for a drab appearance and brilliant tin plating for a glossy finish.
- There is no known toxicity to life on the planet.
- When compared to its higher-cost competitors, such as silver plating and gold plating, tin plating is the most affordable option.
- Tin is useful for more than merely protecting other metals. It also provides a good, clean, low constriction-resistance contact surface as a soft metal. To put it another way, tin creates an ideal surface for electrical current conductivity.
Disadvantages of Tin Plating
Tin’s main flaws are its limited temperature operating window (less than 450° F) and intermetallic phenomena (tin whisker and dendritic crystal growths, or dendrites), the latter of which is well understood but the former not. By bridging and causing shorts in the electronics with which they are assembled, both cause catastrophic damage to electronics. While dendrites migrate due to electromagnetic reactions of tin ions, there is no known or agreed-upon cause for the tin whisker type.
Tin plating Procedures that are Reliable
The following is a guide on limiting and improving tin deposition, based on well-known tin plating process processes developed over the past few decades by several research institutions, for-profit chemical manufacturers, and OEMs:
- Under-plates are included in the pre-plating stages.
- Copper and nickel, which are used as under-plate metals, are the most important for a good tin coating.
- When processing through this pre-plate phase, use “LESS” current density.
- Prior to tin electroplating, make sure the parts are as clean as possible. Contaminants on the surface can lead to poor deposit quality in the future.
- To achieve excellent bonding, bake pieces when necessary to eliminate excess hydrogen. When utilising nickel as an underplate, it is desirable to bake the parts prior to plating to limit the likelihood of intermetallic migration.
- Use lower current densities, minimise or eliminate organics in the bath (matte tin plating with a less luminous matte deposit is preferable), and deposit a minimum of 100 inches (2.5m) during tin plating.
- To simulate a hot-dipped tinned item, reflow the tin covering with hot oils or heat lamps. This gives the coating a longer shelf life, avoiding the aforementioned flaws.
Alloys made of tin
Tin has a number of alloys that are commonly used in the electroplating process. Cobalt, lead, nickel, silver (yet under development), and zinc are among them. When nickel and cobalt are alloyed with tin, they produce similar outcomes. They increase hardness, reduce friction, and can be utilised as a functional and ornamental alternative to chromium. Solderability is improved with the use of lead. Zinc is alloyed specifically for better corrosion resistance and is intended to replace cadmium.
You can also passivate the work with standard chromates by adding up to 30% zinc, which adds an extra layer of atmospheric protection. Finally, tin-silver is still being explored for a variety of uses, including higher temperature solders and a potential replacement for pure silver plating in energy generation equipment.
For over a decade, Smart Microns has dominated the electroplating industry with specialisations in silver and gold plating for use in electrical and electronics. For the past 22 years, Smart Microns has been devoting its resources to researching and designing microns. Smart Creations, headquartered in Chennai, India, and being one of the first South Indian companies to launch the concepts of electroplating and Electrophoretic lacquer (ED lacquers), has Smart Microns as its child firm. The Micron electroplating services provided by Smart Microns utilise over 7 metals, including those that are available in various textured finishes.