Gold Plating

Gold plating is a surface treatment technology with excellent conductivity, corrosion resistance, and biocompatibility. It is widely used in semiconductor, satellite, and medical applications where high reliability is required. This article explains its unique functional benefits and key selection criteria for different applications.

Basic Properties of Gold Plating

Gold is chosen for harsh environments because of its unique physical and chemical properties. The following benefits help maintain long-term performance and improve yield.

• Conductivity: Gold offers high electrical conductivity, surpassed only by silver and copper, helping minimize signal loss.
• Corrosion Resistance: Gold resists oxidation and corrosion, helping prevent increases in contact resistance over the long term.
• Biocompatibility: Gold is generally considered non-toxic to the human body and suitable for use in medical applications.
• Solderability: Because gold does not form a surface oxide, it provides high wettability and helps ensure good solderability and joint reliability.
• Heat Resistance: Gold maintains stable properties even at high temperatures, making it suitable for space and industrial applications.

Main Applications and Industries Served

This section explains how gold plating meets the demanding requirements of each industry.

Semiconductor Packages

When applied to bonding pads and lead frames, gold plating improves wire bond reliability. Coating thickness uniformity and purity directly affect yield, and variations can lead to bonding defects, making precise control of both essential.

Satellite Antennas

Gold plating is sometimes used in space equipment such as satellite antennas, particularly on areas requiring conductivity, corrosion resistance, and surface stability. At high frequencies, the skin effect makes surface conductivity a key factor in communication performance. Because gold maintains conductivity without oxidizing, it is well suited to space environments involving vacuum and extreme temperature changes.

Medical Connectors

For medical devices that come into contact with the human body, biological safety must be evaluated based on the contact site and duration of contact, and stable electrical connections must also be maintained. Gold plating resists wear from frequent mating cycles and maintains low contact resistance over the long term. During design, the plating process must be selected with applicable biological safety requirements under the ISO 10993 series and other international standards in mind.

Types of Gold Plating and Selection Guidelines

The appropriate specifications should be selected based on durability and cost requirements.

It is important to weigh the intended application, required properties, and cost and select the appropriate plating type.

Quality and Technical Requirements for Plating

Achieving reliable plating results requires proper surface preparation. Typically, a nickel barrier layer is formed to prevent metal diffusion from the substrate and improve adhesion. Requirements for coating thickness uniformity and purity vary by application. Particularly stringent standards apply to semiconductor applications because purity control directly affects yield.

Key Points When Requesting Plating Services

Compile the following information to communicate specifications accurately and ensure quality.

• Specify the substrate material and any underlayer material, such as copper, nickel, or aluminum
• Specify the required coating thickness, purity, and hardness
• Provide details of the operating environment (temperature, wear, contact frequency, etc.)
• Confirm the applicable standards for medical or space applications and whether the plating must be suitable for wire bonding

Beyond confirming whether prospective companies can perform the requested plating, it is important to identify companies with rigorous purity control and expertise in surface preparation. If you are looking for an outsourcing partner with proven technical capabilities, refer to “3 Recommended Functional Plating Shops by Industry and Component Type.”