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Buy Heavy Copper PCB Manufacturer in China - Reliable Suppliers for Power Converters with Superior Heat Dissipation Manufacturers, Supplier
Product Description
▶ The core is used in high-current and high-power scenarios (such as power supplies, new energy, industrial control, etc.). The key points of its design, manufacturing and application are as follows:
⚡ Core Features & Application Scenarios
🔋 Core Advantages
- Strong current-carrying capacity: The current-carrying capacity of 70μm copper foil (2 oz) is approximately twice that of 35μm copper foil (1 oz) under the same line width.
- Good heat dissipation: The thick copper layer can quickly conduct heat, reducing the risk of overheating of the device.
- High mechanical strength: Thick copper enhances the PCB's resistance to bending and impact.
🏭 Typical Applications
- Power converters (AC-DC / DC-DC)
- BMS for new energy vehicles
- Industrial frequency converters
- Control boards for welding machines
📐 Key Design Points
1
Selection of Copper Foil Thickness
- Common specs: 70μm (2 oz), 105μm (3 oz), 140μm (4 oz), up to 420μm (12 oz)
- For large current (≥5A): prefer 2–4 oz copper
- For ultra-power (≥20A): select 6–12 oz copper
2
Trace & Current-Carrying Capacity Design
- Formula reference: I = K × W × T0.83
- Example: 2 oz copper (70μm), wire width 5mm → ~15A (ΔT 10℃)
- Keep high-current traces short and wide; avoid narrow necks
- Multi-layer boards: parallel copper layers (e.g., 2×2 oz = 4 oz equivalent)
3
Via & Pad Design
- High-current vias: hole diameter ≥0.5mm, increase via count (~1A per hole)
- Hole wall copper plating ≥20μm (vs. 8–12μm for standard PCBs)
- Thick copper pads: enlarge by 0.2–0.5mm to prevent false soldering
4
Heat Dissipation & Insulation Design
- Design thick copper area as a "copper sheet heat sink"
- Add metallized via array (spacing ≤1mm) to connect heat dissipation layer
- For 70μm copper: wire spacing ≥0.2mm to prevent creepage breakdown under high voltage
🏗️ Manufacturing Process Difficulties & Control
Step 1 Copper Foil Lamination & Etching
Thick copper lamination requires high-temperature and high-pressure lamination (180℃ / 4MPa) to ensure peel strength between copper foil and substrate (≥1.2N/mm).
Thick copper etching: Etching rate is slow (~1μm/min). Etching time must be controlled to avoid side etching (side etching ≤0.05mm). A stepwise etching process should be adopted to reduce line width deviation.
Step 2 Lamination & Warpage Control
The CTE of thick copper layers differs significantly from that of the substrate. A "symmetrical structure" (consistent copper thickness between upper and lower layers) should be adopted during lamination, and a rigid support layer should be added to prevent PCB warping (warping degree ≤0.5%).
Step 3 Surface Treatment
Thick copper surfaces are prone to oxidation. Tin plating (high-temperature tin layer) or nickel-gold plating is preferred over OSP (which may result in incomplete organic film coverage).
The pad area needs an enlarged "solder mask opening window" to ensure proper bonding force between solder and thick copper.
📋 Core Summary
The core of heavy copper PCBs is "high current-carrying capacity + heat dissipation". In terms of design, it is necessary to match the copper thickness and current-carrying capacity requirements. In manufacturing, challenges such as thick copper etching and lamination warping need to be resolved. Heavy copper PCBs are best suited for high-power and high-current industrial and energy scenarios.
📩 Send Inquiry
❓ Frequently Asked Questions (FAQ)
Q What is considered a "heavy copper" PCB and how does it differ from a standard PCB?
A heavy copper PCB uses copper foil with a thickness of 70μm (2 oz) or more, compared to the standard 35μm (1 oz) used in regular PCBs. This increased thickness provides significantly higher current-carrying capacity, better heat dissipation, and improved mechanical strength, making it ideal for high-power applications.
Q What copper thickness should I choose for my high-current application?
For circuits with currents of 5A or above, 2–4 oz copper (70–140μm) is recommended. For ultra-high-power applications requiring 20A or more, 6–12 oz copper (210–420μm) should be selected. The exact choice depends on trace width, allowable temperature rise, and board layout constraints.
Q How do I calculate the current-carrying capacity of a heavy copper trace?
The commonly referenced formula is: I = K × W × T0.83, where I is the current, K is a coefficient based on allowable temperature rise, W is the trace width, and T is the copper thickness. For example, a 2 oz (70μm) copper trace with a 5mm width can carry approximately 15A at a 10℃ temperature rise.
Q What are the main manufacturing challenges of heavy copper PCBs?
The primary challenges include: controlling side etching during the etching process (target ≤0.05mm), managing warpage caused by the CTE mismatch between thick copper and the substrate, and ensuring proper surface treatment. Stepwise etching, symmetrical copper layer structures, and nickel-gold or tin plating are commonly used solutions.
Q Why is via design especially important in heavy copper PCBs?
In heavy copper PCBs, vias carry significantly higher currents than in standard boards. To handle this, via hole diameters should be ≥0.5mm, multiple vias should be used (approximately 1A per via), and the copper plating thickness on hole walls should be ≥20μm. Proper via design prevents overheating and ensures reliable electrical connections between layers.
Q What industries and products commonly use heavy copper PCBs?
Heavy copper PCBs are widely used in industries that require high power and high current handling. Typical applications include AC-DC and DC-DC power converters, battery management systems (BMS) for electric vehicles, industrial frequency inverters, welding machine control boards, solar energy systems, and military or aerospace power electronics.
