Advantages of the PCB Manufacturer PCBONLINE


PCBONLINE uses high-quality sheet materials for heavy copper PCB production. The sheet brand includes Shengyi, Isola, Ventc, etc.

equipment EQUIPMENT

The heavy-copper PCB manufacturer PCBONLINE utilizes automatic machines for electrostatic spraying solder masks on thick-copper PCB.

team TEAM

The professionals from PCBONLINE provide DFM, DFT, DFA, one-on-one engineering support, and PCB manufacturing from proto to bulk production.


High-precision circuit etching, small tolerances, uniform ink thickness, best protection effect, and bright appearance of heavy-copper PCB.


PCBONLINE manufactures and assembles many types of custom heavy-copper PCBs with a copper thickness range from 3oz to 14oz.

shipping TRANSPORT

PCBONLINE provides various thick-copper PCB shipping methods, including air, sea, and rail shipping by DHL, FedEx, and UPS.

What is Heavy Copper PCB

4oz-copper PCB

A heavy-copper PCB, or thick-copper PCB, is a printed circuit board with a copper thickness of more than 2oz.

Heavy-copper PCBs are used in applications that pass high currents. Aluminum PCBs and OSP PCBs can't be made to be thick-copper PCBs.

Typically, heavy copper PCBs have at most 8 PCB layers, and the circuit is relatively simple.

If a PCB has a large PCB copper thickness, such as 4oz, 8oz, and even 14oz, it can withstand a large electricity current to pass through. But remember that the trace space/width of heavy-copper PCB should be large.

At the heavy-copper PCB manufacturer PCBONLINE, the copper thickness range of heavy-copper PCBs falls from 3oz to 14oz. And the thick-copper PCB can have the substrate materials of FR4, PI, PET, and copper.

Heavy Copper PCB Electrostatic Spray Solder Mask

heavy copper PCB

For heavy-copper PCB manufacturing, PCBONLINE uses the electrostatic spray solder mask process to replace the traditional solder mask printing.

The reason why PCBONLINE does not use traditional solder mask printing on thick copper PCBs is that it causes oil to accumulate in the corners of the circuit traces and holes.

Meanwhile, the ink will be very thin in the non-copper areas, and the overall surface of the board is ununiform. When high-current passes through the PCB, electric breakdown may happen at the thinner solder mask areas.

The electrostatic spray solder mask is used for heavy-copper PCB manufacturing because it directly and evenly sprays on the surface of the PCB. And the uniform ink thickness on the entire heavy-copper PCB achieves the best protection and appearance.

Advantages of Heavy Copper PCBs

thick-copper PCB supplier

Heavy copper PCBs are the first option for large-current systems/devices. Engineers choose heavy copper PCBs for these reasons:

Thicker copper brings a bigger circuit cross-sectional area, so heavy-copper PCBs can bear large currents.Thicker copper has smaller resistance, so thick copper PCBs generate less heat and have smaller thermal stress.Heavy copper PCBs provide great thermal dissipation for devices (thermal conductivity of 401W/mK).Heavy copper PCBs provide robust mechanical strength and support to the system/device.

Heavy Copper PCB Manufacturing Capabilities

PCB and PCBA Certifications

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