Plating is a surface treatment process where a thin metal layer is deposited over a substrate to provide corrosion resistance, enhance appearance, offer wear protection, or improve electrical conductivity. Electroplating involves the use of an electric current, whereas electroless plating uses a chemical reduction reaction. Both techniques have significant applications in electronics, aerospace, automobiles, and decoration.

Process Cycle

1. Pre-cleaning (degrease, ultrasonic, acid dip)
2. Surface activation and washing
3. Metal deposition (autocatalytic for electroless, electrochemical for electroplating)
4. Post-treatment (drying, passivation, rinsing)
5. Quality inspection (thickness, adhesion, finish)

Equipment

• Electroplating tanks with rectifiers (DC power supply)
• Anode and cathode fixtures
• Agitation systems (mechanical or air)
• Temperature and pH control systems
• Filtration and chemical dosing units
• Spray and immersion rinse stations

Tooling

Primary:

• Part handling barrel or rack fixtures
• Selective masking plating systems

Secondary:

• Thickness measuring equipment (XRF, coulometry)
• Repeatability inspection fixtures
• Surface conditioning brushes or polishing wheels

Materials

Possible Defects

• Uneven thickness or inadequate coverage
• Delamination or peeling
• Pitting and porosity
• Overplated or burnt areas
• Poor discoloration due to improper rinsing
• Contamination due to improper bath maintenance

Design Guidelines

• Prevent re-entrant corners or recesses (produces uneven plating)
• Provide an even path of current in electroplating designs
• Use drain holes for internal cavities
• Use masking to limit areas of plating
• Provide dimensional growth tolerance stack-up

Cost Drivers

• Plating metal type and thickness
• Part surface area and geometry
• Batch size and masking complexity
• Process type (manual vs. automated)
• Chemical use and disposal cost

Plating imbues significant value in components by maximizing both functional and aesthetic features. Designed fixtures, bath chemistry control, and pre-treatment procedures imbue consistency and efficiency in industrial plating processing.