Thick copper printed circuit boards

Thick copper PCBs, manufactured using pure etching technology, are the first choice for high currents
and are characterized by structures with copper thicknesses from 105 to 400 µm.

Thick copper printed circuit boards Layer structure Cross-section

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We are happy to support you in every phase of the realization of your thick copper PCBs.
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Thick copper printed circuit boards

This classic PCB is your first choice when high currents are unavoidable: the thick copper PCB, manufactured using pure etching technology.

Thick copper PCBs are characterized by structures with copper thicknesses of 105 to 400 µm. These PCBs are used for high currents and to optimize thermal management. The thick copper enables large conductor cross-sections for high current loads and favors heat spreading.

The design is usually a multilayer design or a double-sided PCB. With this PCB technology, it is also possible to combine fine layout structures on the outer layers and thick copper layers in the inner layers.

Technology comparison table for high-current HSMtec® printed circuit boards
MaterialsFR4 (thermostable)
Number of layers2-8
PCB thickness0.5 mm - 3.2 mm
End copper outer layers50, 70, 105, 175, 210 µm
End copper inner layers70, 105, 210, 400 µm
Ladder structuresDepending on the final copper according to the design compass
Smallest drill diametermin. ⅔ of the total copper thickness
Aspect Ratio≤ 1:6
SurfacesSee general technical specifications, no HAL

The specified values represent the maximum power spectrum and may be limited in certain combinations.

  • Electroless nickel/gold
  • Immersion tin
  • Electroplated nickel/gold
  • OSP
  • More on request

Solder resist masks

  • Photosensitive coating systems, thermal final curing
  • Colors: green, red, blue, black glossy, black matt, white, yellow
  • Non-photosensitive coating systems, purely thermal curing: white, black


Additional prints 

  • Labeling/equipment
  • Hole filler/through-hole filler
  • Peelable lacquer
  • Heatsink
  • Carbon


Edge metallization 

In order to improve the EMC protection of a circuit board, to create an electrical contact to the housing of the assembly or to meet increased cleanliness requirements, the front sides of the circuit board contour can be metallized.

Milled vias 

It is possible to produce application-specific components with so-called milled through-holes. The resulting circuit boards can be soldered onto another circuit board as components (interposer) due to their front-side contacting option.

HDI printed circuit board with milled through-hole plating

Contour processing

Contour production: milling and scoring

  • Use filled thermostable base materials with low Z-axis expansion 
  • Calculate resin filling level (material-dependent pre-calculation using the layer build-up program at KSG) 
  • Use sufficiently resin-rich prepregs 
  • Avoid "stacked" copper surfaces and copper-free areas across all layers of the layer structure 
  • Evenly distribute copper surfaces and copper-free areas 
  • Fill large copper-free areas with copper
  • Create sufficiently large residual rings
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Your thick copper PCBs - smarter together.

Take advantage of the direct line to the experienced PCB experts in our technical support team. We are happy to support you in every phase of your project.

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Talk to us in the early development phases of your project and contact our team of experts. Together we will find the solution that will make your product even better.

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Workshop & online consultation

With a workshop at our premises or at your site, we give you the opportunity to discuss the key technical aspects and features of your project in detail.

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Co-Engineering & Support

From design and layout checks to various calculations and thermal analyses - the experienced, competent Technical Support team will be happy to help you.

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