Gold Plating
Hard Gold Plating
The composition of hard gold plating includes additional elements such as cobalt or nickel. These alloying components play a crucial role in improving the hardness and wear resistance of the gold layer. This reinforced coating, with a purity 99.7% gold, acts as a robust barrier against physical wear, corrosion, and environmental factors, ensuring that connectors and contacts maintain consistent performance over extended service periods, even under challenging conditions.
The electrodeposit fulfils the following specification:
This finish is typically used in:
2. Oil & Gas
3. Mil-Aero
4. Space Applications
Pure Gold
With a purity of 99.9%, the use of pure gold is particularly beneficial for components such as transistor headers, lead frames, and pins found in hybrid circuit packages.
The durability and longevity of pure gold plating have significant advantages in aerospace applications. The natural corrosion resistance of gold ensures that components are safeguarded against the severe conditions present in the aerospace sector. This protective coating extends the lifespan of essential parts, thereby decreasing the frequency of replacements and reducing maintenance downtime.
The electrodeposit fulfils the following specification:
This finish is typically used in:
2. Photonics
3. Gas Measurement
4. Space Applications
Immersion Gold
Immersion gold, also known as electroless nickel immersion gold (ENIG), is a two-layer surface finish made up of electroless nickel (nickel phosphorous) and gold:
The typical thickness of immersion gold is 0.05–0.23 µm gold over 4–8.0 µm electroless nickel.
Immersion gold derives its name from the process by which it creates a gold deposit through the immersion of the component in a plating solution. This method facilitates the replacement of nickel ions with gold without requiring any electrical contact. This characteristic distinguishes it from traditional electroplating solutions, where components with electrically isolated tracks, such as printed circuit boards (PCBs), Direct Bonded Ceramics, and Hybrid Packages, cannot undergo gold plating.
Immersion gold is utilized for soldering and aluminium wire bonding applications. In scenarios where aluminium wire bonding is necessary, it is crucial to manage the base electroless nickel and limit contaminants to parts per million levels to prevent the formation of black pad. The black pad issue is particularly troublesome due to its infrequent occurrence and the challenges associated with its detection. This problem typically results in brittle fractures at the interface between the solder joint and the component pad, which are exacerbated by thermal cycling.
This finish is typically used in:
2. Mil-Aero (Soldering)