Thick copper PCBs

Overview of thick copper technology

This PCB classic is the first choice when high currents are unavoidable: the thick copper PCB, manufactured in genuine etching technology. Thick copper PCBs are characterised by structures with copper thicknesses from 105 to 400 µm. These PCBs are used for large (high) current outputs and for optimisation of the thermal management. The thick copper allows large PCB-cross-sections for high current loads and encourages heat dissipation. The most common designs are multilayer or double-sided. 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.

Your advantages

  • High currents and heat dissipation in the circuit board
  • Targeted partial increase in cross-section for high-current paths
  • Reduction of space requirements for high-current conductor systems
  • From sample to series production from a single source
  • Power and control electronics on a single board
  • PCB production and processing with standard materials and series processes
  • Cost optimisation of the final product

When extremely high currents are required

Power and control electronics on a single board

Targeted partial increase in cross-section for high-current paths

Close-up of a thick copper PCB

Materials FR4 (thermostable)
Number of layers 2-8
PCB thickness 0.5 mm - 3.2 mm
Final copper outer layers 50, 70, 105, 175, 210 µm
Final copper inner layers 70, 105, 210, 400 µm
Conductor structures Depending on final copper according to design compass
Minimum drilling diameter min. ⅔ of the total copper thickness
Aspect ratio ≤ 1:6
Surfaces See general technical specifications, No HAL

The values specified represent the maximum range of services and may be restricted in certain combinations.

Solder resist masks 

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

Surfaces 

  • Chemical nickel/gold
  • Chemical tin
  • Electroplated nickel/gold
  • HAL or HAL lead-free
  • OSP
  • others on request

Additional printing 

  • Identification/assembly
  • Hole filler/through hole filler
  • Peelable solder mask 
  • Heatsink
  • Carbon

Edge plating 

The end faces of the PCB contour can be plated in order to improve the EMC protection of a PCB, make electrical contact with the housing of the module or meet increased cleanliness requirements. 

Edge plating

Milled plated through holes 

It is possible to produce application-specific components with so-called milled plated through holes. Due to the possibility of contact on the front side, the resulting PCBs can be soldered as components to another board (interposer).

Milled plated through holes.

Contour machining

Contour production: milling and scoring

  • Use filled thermostable base materials with low Z-axis expansion 
  • Calculate resin filling level (material-dependent pre-calculation using layer stack-up at KSG)
  • Use sufficient resin-rich prepregs
  • Avoid "stacked" copper surfaces and copper-free areas across all layers of the layer stack up
  • Evenly distribute copper surfaces and copper-free areas 
  • Fill large copper-free areas with copper
  • Generate sufficiently large residual rings

Contact partner

Picture Georgi Georgiev

Georgi Georgiev
Project Engineer | KSG GmbH
Phone+49 3721 266-204
geogi.georgiev@ksg-pcb.com

Portrait of Johann Hackl

Johann Hackl
Product Manager
Phone+43 2985 2141-601
johann.hackl@ksg-pcb.com