Custom Pre-Tinned Connectors Solve the Gold Embrittlement Problem

By Contributed Article | October 14, 2025

Gold over nickel plating is an excellent choice for signal transmission in RF PCB connectors. However, an excess amount of gold in the solder joint can create a gold-tin compound, making the solder joint susceptible to breakage. A custom solution solves the problem.

By SV Microwave

Gold over nickel plating is an excellent choice for signal transmission, as this material resists tarnish and does not oxidize. It offers consistent contact resistance and high conductivity, surpassed only by silver and copper among the noble metals. Gold plating is widely used and highly reliable in brass, BeCu, and stainless steel bodies used in RF PCB connectors. However, engineers must be vigilant about one defect this material may introduce to a circuit: the potential for remnants of the gold plating to appear in the solder joint when the connector is soldered to the PCB. This occurs when an excess amount of gold plating accumulates in the solder joint, where it can create AuSn3, a gold-tin compound which is visible as gold striations under a microscope. The presence of this gold embrittlement is a serious defect, especially in high reliability applications, as it makes the solder joint susceptible to breakage under mechanical stress, like shock and vibration.

SV Microwave can customize connectors with a specifically engineered pre-tinned finish that eliminates gold in the solder area

Several solutions exist to relieve this problem. Using a minimal amount of gold plating (typically ≤ 50 µin) reduces the potential for excess material to enter the joint area. Carefully controlling the plating process can also ensure consistent plating quality and finish. Another solution to gold embrittlement is the use of specifically engineered pre-tinned finishes that eliminate gold in the solder area.

This strategic material use optimizes connectors for high-shock and high-vibration environments by ensuring that the solderable areas, including those prone to solder-wicking, are free from gold. This process also satisfies the requirements of J-STD-001, a standard issued by IPC for soldered electrical and electronic assemblies.

SV Microwave offers a range of single-port, two-port, four-port, and eight-port PCB surface mount connectors suitable for Military, Aerospace, RF testing, and prototyping needs. Current interface configurations include the SMP, SMPM, and SMPS series.

A pre-tinned solution for gold embrittlement offers benefits such as improved solderability and cost-sensitivity. In some harsh environment or critical applications, alloyed gold may be a better choice. Making this determination involves the consideration of multiple factors. Engineers should work closely with a connector supplier that can help evaluate the overall system requirements, operating environment, timeline, and budget for an application. For a project with a more complex design and tight mechanical tolerances, working with a supplier that has customization capabilities can help create the ideal solution. For example, SV Microwave can help designers evaluate the plating as well over configuration to create custom RF connectors with unique port configurations. In some situations, the process can be expedited with the use of a custom configurator tool. Humboldt, SV Microwave’s online multiport assembly builder, allows designers to create precise cable assembly harnesses easily using a drag-and-drop platform.

With SV Microwave’s Humboldt custom configuration tool, designers can quickly configure a simple or complex harness to exact specifications, receive an instant quote, and print datasheets. Shipping is available in 15 business days.

A faster option, SV Microwave’s Rapid Response builder offers a quick and convenient solution for those needing single-port custom cable assemblies, with shipping available in 10 days. With thousands of connector and cable combinations available, the Rapid Response platform allows users to customize cable assemblies with ease. VITA 67.1/2 and VITA 67.3 contacts are now available in Rapid Response, along with custom configurations available for both Ø.047 & Ø.085 cable types, with cable lengths ranging from 3” to 99”.

Visit SV Microwave to learn more about custom solutions for high reliability applications.