Before plating, the busbar surface must be thoroughly cleaned to ensure proper adhesion of the plating material. Steps include: Degreasing – Removes oils and contaminants. Acid Pickling – Removes oxides and scales (e.g., using hydrochloric or sulfuric acid). Rinsing – Ensures no residues remain.
Author: Robby
Conductive busbars are plated using various metal coatings to enhance their electrical conductivity, corrosion resistance, solderability, and durability. The plating process typically involves the following steps and methods:
Before plating, the busbar surface must be thoroughly cleaned to ensure proper adhesion of the plating material. Steps include:
Degreasing – Removes oils and contaminants.
Acid Pickling – Removes oxides and scales (e.g., using hydrochloric or sulfuric acid).
Rinsing – Ensures no residues remain.
The busbar acts as the cathode in an electrolytic bath containing metal ions (e.g., silver, tin, nickel, or gold).
An electric current reduces the metal ions, depositing them onto the busbar surface.
Common plating metals:
Silver (Ag) – Excellent conductivity, oxidation resistance (used in high-performance applications).
Tin (Sn) – Good solderability, cost-effective, prevents copper oxidation.
Nickel (Ni) – Enhances corrosion resistance and acts as a barrier layer before gold plating.
Gold (Au) – Superior corrosion resistance and conductivity (used in aerospace and high-reliability electronics).
Does not require an external current; instead, a chemical reduction process deposits metal (e.g., nickel-phosphorus or nickel-boron).
Provides a uniform coating, even on complex shapes.
Often used for nickel plating before additional layers (e.g., gold).
The busbar is immersed in molten metal (e.g., tin or solder alloys).
Forms a thick, durable coating (common in power distribution systems).
Passivation – Improves corrosion resistance (e.g., chromate treatment for tin-plated busbars).
Annealing – For tin-plated busbars, reflowing improves adhesion and uniformity.
Quality Testing – Checks for thickness (XRF or micrometer), adhesion (tape test), and conductivity.
| Base Material | Plating Layer(s) | Purpose |
|---|---|---|
| Copper (Cu) | Tin (Sn) | Prevents oxidation, improves solderability |
| Copper (Cu) | Silver (Ag) | High conductivity, low contact resistance |
| Copper (Cu) | Nickel (Ni) + Gold (Au) | Corrosion resistance (e.g., for aerospace) |
| Aluminum (Al) | Nickel (Ni) or Tin (Sn) | Prevents galvanic corrosion |
Silver-Plated Busbars – High-frequency and high-current applications (e.g., power electronics, EV batteries).
Tin-Plated Busbars – Cost-effective for electrical panels and automotive systems.
Gold-Plated Busbars – Critical in aerospace, medical, and RF applications.