The surface treatment process for copper busbars is relatively simple:
(1) Pickling:
Pickling solution: 98 liters of industrial sulfuric acid (no need to add water) + 2 liters of industrial hydrochloric acid
Temperature: Room temperature
Time: 1-2 minutes
(2) Passivation:
Passivation solution: Approximately 5% chromium trioxide aqueous solution (there is a chromium-free passivation solution, but the formula is unknown)
Temperature: Room temperature
Time: 2 minutes
(3) Washing and drying
Soaking in tap water (1-2 minutes) ---- Rinsing with tap water (slight rinsing) ---- Rinsing with deionized water ---- Drying or baking
For small copper busbars, electrolysis ---- passivation ---- drying can be used. This is more environmentally friendly but less efficient.