Gold Plating Thickness in Interconnects

Connectors typically come with either a tin plating or gold plating. Determination can be made among many based on environment, insertion/extractions and applications with low voltages and currents.??

With the increasing price of gold in the 1970s and 1980s, the connector industry, the initial standard gold thickness of 2.5 um (100 microinches) was gradually reduced until gold flash over nickel was proposed as the ultimate cost reducer.?For decades, manufacturers of electronics products have used gold plating to protect the connectors that are essential for joining electrical circuits together. Gold is the preferred material because of its good electrical conductivity, ability to resist corrosion and wear. Determining the appropriate gold plating thickness can be a vital decision to maximize the durability and life cycle of the connector.

The thickness of gold plating can vary significantly.?It’s possible to apply a gold coating ranging typically from 4uin to 100uin. While a thicker layer will decrease the workpiece’s porosity and enhance corrosion protection, a coating that’s too thin may not provide sufficient corrosion and wear resistance.

Cost is a huge factor when considering the ideal gold plating thickness. As a precious metal, gold can be one of the most expensive plating materials, which may result in a higher project cost. As a rule of thumb, start with a thickness level that’s as low as possible for your application, then increase it if necessary.

• Thin (Gold Flash):?A thin gold coating in the 4uin to 10uin range will work well for low-contact applications or when you require excellent solderability. Consider this level when using connectors in a controlled environment where wear resistance is not an issue.
• Moderate:?Consider a moderately thick gold coating 15uin to 30uin for workpieces that face exposure to ordinary amounts of environmental corrosion or wear cycles, as well as when soldering connectors.
• High (Mil Standard):?Apply a thicker gold layer 40uin to 50uin?for?workpieces exposed to aggressive environments where corrosion and chemical attack pose a substantial risk. This level will also increase wear resistance in moderate to high-cycle settings.

It may seem difficult to determine the right thickness for gold plating connectors and contacts. Connectors must perform reliably even under harsh conditions, and they can only do so when the plating is properly designed with the right amount of thickness. As an added factor, gold can be an expensive material to procure, meaning it’s important to only make plating as thick as it needs to be — thicker than needed means wasted money.