Heavy Copper Printed Circuit Boards Manufacturer

High-quality, quick-turn heavy copper PCB fabrication services.

Heavy copper PCBs are printed circuit boards with copper weight ranging from 4 oz/ft to 10 oz/ft on either its internal or external layer that qualifies as a heavy copper printed circuit board. You can also call a heavy copper PCB a thick copper PCB. Heavy copper PCBs are different from the extreme copper PCBs as the latter has copper within the range of 20 oz to 200 oz per sq. ft.

Heavy copper PCBs have a very dense yet simple board design. These PCBs are subject to special plating and etching techniques like step plating or differential etching. There is no need to create high current or high voltage circuits on separate boards with this thick copper board. However, heavy copper conductors can affect the thickness of the PCB. Thus, you should always consider the copper thickness while designing the circuit. Further, the thickness of the rich copper also decides the current carrying capacity of the PCB.


Our Capabilities

PadPCB is a specialist in heavy copper PCB fabrication. We design and manufacture high-quality thick copper PCBs at competitive market prices. We utilize copper weights of up to 15oz (525μm). Check our capabilities in the following table:

Base MaterialFR/4 all TGs, Aluminum, Ceramic, Teflon, Polyamide, Copper
Quality GradeStandard IPC 2
Copper Thickness4 Oz – 10 Oz
Extreme Heavy Copper20 Oz – 200 Oz
SoldermaskRed Oil/Green/Blue/Black/White
Surface FinishingImmersion Gold, OSP, and HASL
OutlinePunching, Routing, V-Cut
Maximum Panel Size22.8 ʺ *18.9ʺ
Maximum Number of Layers16
Finished Thickness0.020 ʺ – .275 ʺ
Minimum Soldermask Clearance6 MIL
Minimum Solder Dam Width5.5 MIL
ViasBlind and Buried Vias
HolesMinimum Drill Bit Hole Size: .012ʺ
Minimum Holes Size: .008″ +.005″/-.008″
Maximum Hole Aspect Ratio = 10:1
Controlled Impedance+/- 10%
Minimum Silkscreen Line Width8 MIL

Benefits of Heavy Copper PCB

The heavy copper PCBs are a reliable wiring platform. Industries are increasing the use of these thick PCBs. Here are a few benefits that these PCBs offer:

  • Multiple uses: The weight of heavy copper PCB affects the board quality and performance. So, not all boards can endure these PCBs. Heavy copper PCB boards are mainly used across devices where power and signal levels vary.
  • Compact size: A heavy copper board can withstand high current, high temperature, frequency, and recurring thermal cycles. This sustainability is the result of many layers stacked upon a single layer. This multiple stacking decreases the total size and weight of the board, thus creating tiny but high-performing circuits.
  • Thermal resistance: Regular PCB boards’ fan cooling system cannot disperse the high heat generated by them. As a result, this heat degrades the PCB quality by affecting soldered joints and destroying them. However, heavy copper PCBs have a high conducting capacity.; thus, they create less heat which is dispersed easily.
  • Better load sharing: There is no need to create multiple duplicates and parallel layers in heavy copper PCBs. The numerous parallel layers create load-sharing issues. However, in heavy copper PCBs, you can combine the copper with copper vias, thus avoiding forming multiple layers.
  • Board with high mechanical strength: As in heavy copper PCB, multiple layers and plated-through holes increase its overall strength.

Application of heavy copper PCB:

You can use Heavy copper Printed circuit boards for different purposes, such as heat dissipation, power converters, high power distribution, and planar transformers. Several industries require heavy copper clad boards for their electronic controls. Electronic devices and power supply systems also use heavy copper PCBs extensively.

Several industries that use heavy copper PCB boards are:

  • Automotive industry
  • Power supplies and power converters
  • Welding equipment
  • Torque controls
  • Overload relays
  • Power line monitors
  • Power distribution
  • Solar panel manufacturing
  • Protection relays

How is Heavy Copper PCB Fabricated?

The fabrication of heavy copper PCB requires etching and plating. With these techniques, PCB manufacturers increase copper thickness in sidewalls and plated holes. However, you cannot opt for a normal etching process as it results in uneven etched margins. Here, you need a unique etching and plating process to add that extra thickness of copper, and these processes result in straight and even margins.

During the fabrication process, heavy copper PCBs are electroplated. This process increases the thickness of the PTH barriers. This technique also results in shrinkage of layer count and reduction of impedance reduction. However, if PCBs undergo multiple cycles, the plated holes may become weak. 

There are mainly two methods of fabricating heavy copper PCBs:

Embedded copper method:

PCB fabrication takes place using a flat surface. In this, manufacturers insert prepreg resin along with copper, and the thickness of copper depends on the thickness of resin.

Blue bar method:

In this process, manufacturers insert thick copper bars into PCBs to add thickness and transmit additional current. As only a few lines of copper can carry significant current in high power circuits, it helps reduce the extra weight of PCB. However, it is essential to consider the level of copper fill between inner layers to prevent extra delamination in multilayer boards.

Difference between a Standard PCB and Thick Copper PCB?

  • The main difference between a standard PCB and a thick copper PCB is the thickness of the copper plating on the circuit boards. On a standard PCB, the copper layer weighs one ounce to 35 micrometres, while on a heavy copper PCB, it weighs around 4 oz to 140 micrometers.
  • Standard PCBs cannot conduct high current values, while a heavy copper PCB can transmit significantly high current levels.
  • Heavy copper PCBs have higher mechanical strength than standard PCBs. A thick copper PCB can enhance heat conductivity while handling mechanical stress. 
  • Standard PCBs use copper etching and plating techniques in fabrication, while a heavy copper PCB uses step plating and differential plating. 
  • Heavy copper PCBs are capable of efficient thermal distribution, they are suitable for high-end applications where standard PCBs do not work.