heat sink fins surface natural and anodized example

Surface finishing – Protection, performance and durability for heat sinks

Surface finishing improves corrosion resistance, thermal conductivity, and the lifespan of air and liquid coolers. Whether anodizing, nickel plating, copper, or gold coatings – each technology offers targeted advantages for specific power electronics applications.

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COOLTEC surface finishing technologies

Anodizing

Anodizing creates a robust oxide layer on aluminum, protecting the material from corrosion while optimizing thermal conductivity.

Benefits:

  • Protects against environmental and chemical exposure

  • Improves thermal and electrical conductivity

  • Coloring allows for aesthetic surface appearance

  • Increases heat sink longevity

Chromium-VI-free passivation

This eco-friendly process forms a thin protective layer that shields aluminum heat sinks from corrosion without using harmful Chromium VI.

Benefits:

  • High corrosion protection

  • Complies with RoHS and REACH standards

  • Improves adhesion for subsequent coatings

  • Sustainable and environmentally friendly

Chemical and electroplated nickel

Nickel plating protects against oxidation, improves thermal conductivity, and increases mechanical resistance – applied chemically without electricity or electroplated for maximum density and adhesion.

Benefits:

  • Excellent corrosion resistance

  • High wear resistance

  • Optimizes thermal and electrical conductivity

  • Base layer for further coatings

Copper coating

An electrolytic copper layer enhances thermal and electrical conductivity, ideal for direct SMD soldering on the heat sink.

Benefits:

  • Improved thermal connection of electronic components

  • High mechanical stability

  • Excellent corrosion protection

  • Versatile for further refinements

Gold coating

Applied on a nickel base, this coating provides excellent electrical conductivity and minimal contact resistance – ideal for high-frequency applications.

Benefits:

  • Optimal electrical conductivity

  • Minimized contact resistance

  • Direct SMD soldering on the heat sink possible

  • High-quality, aesthetic appearance

Nickel-tin coating

Combines the advantages of nickel and tin for durable, corrosion-resistant heat sinks.

Benefits:

  • High wear resistance

  • Improved thermal and electrical conductivity

  • Uniform surface for further refinements

  • Ideal for high-performance applications

Powder coating

Electrostatic powder is baked on to form a robust protective layer.

Benefits:

  • Excellent corrosion protection

  • High mechanical durability

  • Improves thermal conductivity

  • Environmentally friendly and solvent-free

  • Wide variety of colors and textures

Nanocoating using SOL-Gel process

A nanoscale coating protects against corrosion, chemical exposure, and mechanical stress without affecting thermal conductivity.

Benefits:

  • Ultrathin, highly durable protective layer

  • Optimized heat dissipation

  • Can be hydrophobic, oleophobic, or antistatic

  • Precise coating of complex geometries

  • Environmentally friendly and sustainable

Perfect surfaces for the highest demands

Our surface finishes combine performance, protection, and design – for heat sinks that operate reliably in high-performance applications.

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