Which should be used for the center conductor of an extremely fine coaxial cable bundle: tin-plated or silver-plated? A comprehensive analysis of performance differences

In high-speed electronic devices, micro coaxial cable has become the core carrier of internal high-speed signal chains, covering applications such as notebooks, tablets, camera modules, servers, and high-speed interfaces (such as Thunderbolt, HDMI, MIPI, etc.). The central conductor, as a key part of the cable transmission, its material and surface treatment process directly affect the integrity of high-speed signals and the life of the cable. The common treatment methods currently include tin plating and silver plating, which have obvious differences in performance and applicable scenarios. The following will explain from aspects such as characteristics and application selection.

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One, the characteristics of tin-plated center conductor

Tinning is mainly used to protect copper conductors from oxidation, enhance corrosion resistance, and improve stability during welding. As tin can form a stable oxide film in the air, using extremely fine tinned conductor coaxial cables in everyday operating environments offers good protective performance. In addition, tin has good wettability, making it easier for the cables to achieve reliable connection effects during welding or crimping.

But from the perspective of high-frequency electrical performance, the conductivity of tin is relatively low, only about 1/13 of silver. When the signal is in a high-speed transmission state, it will concentrate on the surface of the conductor due to the skin effect, and at this time, the low conductivity of the tin-plated layer will amplify the insertion loss and cause signal attenuation. Therefore, tin-plated conductors are more suitable for applications with medium-speed transmission or low requirements for high-frequency loss.

 

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Silver center conductor characteristics

Silver plating is one of the most effective ways to improve the electrical performance of high-speed cables. Silver has the highest electrical conductivity among all metals (about 105% IACS compared to copper), showing extremely low surface resistance in high-frequency transmission, which can effectively reduce attenuation caused by skin effect. Silver-plated central conductors can significantly reduce high-frequency losses, enhance signal integrity and anti-interference ability, and are suitable for designs with higher data rates and longer cables.

In addition, silver has better heat resistance and antioxidant properties than tin, making it more advantageous under high temperatures, long-term use, or harsh environmental conditions. However, due to its higher material cost and the possibility of sulfidation, appropriate protection and cost assessment are required when it is applied.

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Chapter 3 Selection of Application Scenarios

3.1 If the product emphasizes reliability, solderability, and cost control, such as medium-speed signals or general internal connections, a tin-plated center conductor is a more common choice.

3.2 If the product focuses on high-speed transmission, low loss, and strict signal integrity requirements, such as MIPI, HDMI, USB4, Thunderbolt, and other high-speed links, silver-plated conductors have more advantages.

Engineers usually weigh the tin-plated or silver-plated solutions based on transmission speed, cable length, application environment, and overall cost requirements. In some high-end equipment, the use of silver-plated cables has become an inevitable trend.

Tinning and silver plating have their respective characteristics in the central conductor of extremely thin coaxial cable bundles: tinning emphasizes weldability, oxidation resistance, and cost control, while silver plating meets the requirements of low loss and high signal integrity for high-speed transmission. In actual selection, it is necessary to comprehensively judge based on factors such as the operating environment, transmission speed, and cost budget in order to find the best balance between performance and cost.

I amSuzhou Huichengyuan Electronic TechnologyLong-term focus on the design and customization of high-speed signal cable harnesses and ultra-fine coaxial cable harnesses, committed to providing stable and reliable high-speed interconnection solutions. For more information or project requirements, please contact Manager Yin.：18913280527 (WeChat same number)。