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Heavy Copper PCB
What Is a Heavy Copper PCB?
Heavy Copper PCB, also known as Thick Copper PCB, is a printed circuit board manufactured with significantly thicker copper than a standard PCB. Copper weights of 3 oz (105 μm) or more are commonly classified as heavy copper.
The thicker copper increases the current-carrying capacity of PCB traces and planes while reducing electrical resistance and improving heat dissipation. Heavy Copper PCBs are widely used for high-current and high-power applications where standard 1 oz or 2 oz copper cannot meet the required electrical, thermal, or mechanical performance.
Heavy copper can be manufactured on the outer layers, inner layers, or selected layers of a multilayer PCB. Different copper weights can also be combined within the same board to accommodate both high-current power paths and high-density signal routing.
Why Heavy Copper PCBs Are Used?
Heavy Copper PCBs are designed for applications that require high current capacity, efficient heat transfer, and reliable operation under demanding electrical and thermal conditions.
Compared with standard copper thicknesses, heavier copper provides a larger conductive cross-section for current flow and helps reduce resistance and power loss. The additional copper mass also provides better heat spreading and increased mechanical strength.
Heavy copper is particularly suitable for power supplies, power converters, automotive electronics, battery systems, industrial equipment, renewable energy systems, and other high-power applications.
Advantages of Heavy Copper PCB
Higher Current-Carrying Capacity
Thicker copper allows PCB traces and copper planes to carry higher currents without requiring excessively wide conductors. Current capacity depends on copper thickness, trace width, allowable temperature rise, layer position, and cooling conditions.
Better Heat Dissipation
The increased copper thickness provides an efficient thermal path for conducting and spreading heat generated by high-power components and current-carrying traces.
Lower Electrical Resistance
Heavy copper reduces the resistance of conductive paths, helping minimize I²R losses and improve the efficiency of high-current circuits.
Higher Mechanical Strength
The additional copper provides increased mechanical strength around plated holes, terminals, connectors, and high-current interconnections.
Improved Reliability
Heavy copper construction can provide greater stability under high electrical loads and demanding thermal conditions, making it suitable for power-intensive and industrial applications.
Heavy Copper PCB Manufacturing Capabilities
SLLPCB provides high-precision Heavy Copper PCB manufacturing from prototype to mass production. Our capabilities cover high copper weights, thick boards, high layer counts, HDI structures, mixed copper weights, and complex multilayer constructions.
| Parameter | SLLPCB Capability |
|---|---|
| Copper Weight | 3 oz to 12 oz |
| Approximate copper thickness | 105–420 µm (3–12 oz) |
| Inner Layer Copper | Up to 12 oz |
| Outer Layer Copper | Up to 12 oz |
| Layer Count | Up to 68 layers |
| Board Thickness | Up to 14 mm |
| Minimum Trace Width | Down to 50 µm |
| Minimum Trace Spacing | Down to 50 µm |
| Minimum mechanical hole | 0.15 mm |
| Via Technology | Through-hole, blind vias, buried vias & microvias |
| Aspect Ratio | Up to 18:1 |
| PCB Type | Single-sided, double-sided & multilayer |
| Copper Structure | Uniform and mixed copper weights |
| Materials | FR-4, High-Tg, low-loss, metal-backed & specialty materials |
| Surface Finishes | ENIG, HASL, OSP, Immersion Silver, Immersion Tin & more |
| Solder Mask | Green, black, blue, red, white & other options |
| Silkscreen | White, black & customized options |
| Board Size | Maximum processing width: 900 mm; maximum length: 2100 mm |
| Production | Prototype, small batch & mass production |
| Engineering | DFM review, stackup design & manufacturing consultation |
SLLPCB can also combine heavy copper with HDI PCB, fine-pitch routing, controlled impedance, back drilling, buried vias, microvias, and other advanced PCB technologies.
For demanding multilayer designs, copper thickness can be customized layer by layer according to current requirements, thermal requirements, routing density, and stackup constraints.
Heavy Copper PCB Manufacturing
Heavy copper manufacturing requires precise control of copper etching, plating, drilling, lamination, registration, and copper distribution.
SLLPCB uses specialized manufacturing processes for thick copper structures to maintain the required trace geometry and finished copper thickness. Engineering review is performed before production to evaluate trace width and spacing, copper distribution, via structures, board thickness, and lamination requirements.
Heavy copper can also be integrated with high-Tg and specialty materials for applications exposed to high temperatures, high power density, or demanding operating environments.
Our engineering team can review your Gerber files and manufacturing specifications to determine the appropriate copper weight, stackup, trace geometry, and manufacturing process.
Heavy Copper PCB Applications
| Application | Heavy Copper PCB Requirement |
|---|---|
| EV & Automotive | High-current power distribution, motor control and thermal management |
| Battery Systems | High-current paths and low-resistance power connections |
| Power Supplies & Converters | High-current switching and power conversion |
| Motor Drives & Inverters | High-current switching and thermal performance |
| Solar & Renewable Energy | Power conversion and energy distribution |
| UPS & Power Distribution | High-current power paths and reliability |
| Industrial Power Electronics | High current, thermal cycling and mechanical durability |
| Data Center Power Systems | High-current power delivery and thermal management |
Heavy Copper PCB Manufacturing at SLLPCB
SLLPCB combines PCB manufacturing with advanced PCB technologies to support complex high-current designs.
Our manufacturing capabilities include copper weights up to 12 oz, high layer-count multilayer PCBs, HDI structures, controlled impedance, mixed copper weights, specialty materials, and customized board constructions.
Heavy Copper PCBs can be manufactured with different copper weights across individual layers, allowing power layers to use heavy copper while signal layers maintain thinner copper for higher routing density.
For applications requiring both high current and high-density routing, SLLPCB can integrate heavy copper with blind vias, buried vias, microvias, back drilling, and advanced multilayer stackups.
From prototype and engineering samples to volume production, we provide manufacturing support based on your electrical, thermal, mechanical, and application requirements.
Send your Gerber files, drawings, or PCB specifications to our engineering team for a DFM review and quotation.
Heavy Copper PCB FAQ
What copper weight is considered heavy copper?
3 oz (105 μm) or more finished copper is commonly considered Heavy Copper PCB. Copper weights can be increased according to the current, thermal, and mechanical requirements of the application.
How thick can Heavy Copper PCB be?
SLLPCB supports copper weights from 3 oz to 12 oz and finished copper thicknesses up to 420 μm depending on the board construction and manufacturing requirements.
Can heavy copper be used on inner layers?
Yes. Heavy copper can be manufactured on inner layers as well as outer layers. Different copper weights can also be combined within the same multilayer PCB.
Can Heavy Copper PCB use HDI technology?
Yes. Heavy copper can be combined with blind vias, buried vias, microvias, back drilling, and other HDI technologies for designs requiring both high-current power paths and high-density routing.
What industries use Heavy Copper PCBs?
Heavy Copper PCBs are commonly used in power electronics, automotive and EV systems, battery management, renewable energy, industrial equipment, power distribution, aerospace, data centers, and high-performance computing.
