Used when a single layer isn’t sufficient. Common stacks: Nickel + Gold (Ni/Au) – Prevents diffusion, improves durability (common in aerospace & RF). Nickel + Silver (Ni/Ag) – Balances cost and performance (avoids silver migration). Copper + Nickel + Tin (Cu/Ni/Sn) – For aluminum busbars to prevent galvanic corrosion. Nickel + Palladium + Gold (Ni/Pd/Au) – High-end electronics (prevents fretti
Conductive busbars can be plated with various metal layers, each offering distinct properties such as enhanced conductivity, corrosion resistance, solderability, or durability. The types of plating layers can be categorized based on the metal used and their functional purpose. Here’s a breakdown:
A single metal coating applied directly on the busbar (usually copper or aluminum). Common options:
Tin (Sn) – Affordable, good solderability, prevents oxidation.
Silver (Ag) – High conductivity, low contact resistance, tarnish-resistant.
Nickel (Ni) – Corrosion and wear resistance, often a base layer.
Gold (Au) – Excellent corrosion resistance, used in high-reliability applications.
Zinc (Zn) – Low-cost corrosion protection (common for steel busbars).
Used when a single layer isn’t sufficient. Common stacks:
Nickel + Gold (Ni/Au) – Prevents diffusion, improves durability (common in aerospace & RF).
Nickel + Silver (Ni/Ag) – Balances cost and performance (avoids silver migration).
Copper + Nickel + Tin (Cu/Ni/Sn) – For aluminum busbars to prevent galvanic corrosion.
Nickel + Palladium + Gold (Ni/Pd/Au) – High-end electronics (prevents fretting corrosion).
Specialized coatings with mixed metals for unique properties:
Tin-Lead (Sn/Pb) – Historically used for solderability (now phased out due to RoHS).
Tin-Bismuth (Sn/Bi) – RoHS-compliant alternative to Sn/Pb.
Silver-Plated Copper (Cu-Ag Clad) – Combines high conductivity with surface protection.
While not traditional "plating," these are sometimes used alongside metal layers:
Conductive Polymers – For anti-corrosion in harsh environments.
Oxide Passivation (e.g., Alodine for Al busbars) – Enhances corrosion resistance.
| Plating Type | Key Benefit | Typical Applications |
|---|---|---|
| Tin (Sn) | Solderability, cost-effective | Electrical panels, automotive |
| Silver (Ag) | Best conductivity, low oxidation | High-power systems, EV batteries |
| Nickel (Ni) | Corrosion/barrier layer | Base for gold/silver plating |
| Gold (Au) | Extreme corrosion resistance | Aerospace, medical, RF |
| Multi-Layer (Ni/Au, Ni/Ag) | Balanced performance | High-reliability electronics |
The number of plating layers varies from single-layer (e.g., Sn, Ag, Ni) to multi-layer (e.g., Ni/Au, Ni/Ag) and even alloy/composite platings (e.g., Sn-Bi). The choice depends on:
Electrical requirements (conductivity, contact resistance).
Environmental factors (humidity, temperature, corrosive agents).
Cost constraints (silver and gold are expensive).