ODM Heavy Copper PCB from China Suppliers - High Current Carrying Capacity & Excellent Heat Dissipation Factory Solutions Suppliers, Pricelist
Product Description
What is Heavy Copper PCB?
Core Features and Application Scenarios
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 quickly conducts heat, reducing the risk of overheating of the device.
High Mechanical Strength
Thick copper enhances the PCB's resistance to bending and impact.
Power converters (AC-DC/DC-DC), BMS for new energy vehicles, industrial frequency converters, control boards for welding machines, etc.
Key Design Points
- Common specifications: 70μm (2 oz), 105μm (3 oz), 140μm (4 oz), and up to 420μm (12 oz) in extreme scenarios.
- Matching scenarios: For large current (≥5A) circuits, 2–4 oz copper is preferred. For ultra-power scenarios (≥20A), 6–12 oz copper should be selected.
- Must combine copper thickness, line width, and temperature rise requirements (usually designed based on a temperature rise of 10℃).
- Formula reference: I = K × W × T0.83 (I = current, K = coefficient, W = line width, T = copper thickness).
- Example: 2 oz copper (70μm), wire width 5mm → current carrying capacity ≈ 15A (temperature rise 10℃).
- Keep high-current traces as short and wide as possible; avoid narrow necks (sudden changes in line width can cause local overheating).
- Multi-layer boards can use "parallel connection of multiple copper layers" (e.g., 2 layers of 2 oz = 4 oz equivalent) to enhance current-carrying capacity.
- For high-current vias, increase hole diameter (≥0.5mm), increase number of vias (estimated at 1A per hole), and ensure copper plating thickness on hole wall ≥20μm (vs. 8–12μm for ordinary PCBs).
- Thick copper pads should be enlarged by 0.2–0.5mm compared to ordinary pads to prevent the copper layer from dissipating heat too quickly during welding, which may cause false soldering.
- The thick copper area can be designed as a "copper sheet heat sink", or a metallized via array (via spacing ≤1mm) can be added to connect to the heat dissipation layer.
- Wire spacing for thick copper layers should be widened (for 70μm copper, spacing ≥0.2mm) to prevent creepage breakdown under high voltage.
Manufacturing Process Difficulties and Control
▶ 1. Copper Foil Lamination and Etching
Thick copper lamination: High-temperature and high-pressure lamination (180℃ / 4MPa) is required to ensure the peel strength between the copper foil and the substrate (≥1.2N/mm).
Thick copper etching: The etching rate is slow (approx. 1μm/min), and etching time must be controlled to avoid side etching (side etching amount ≤0.05mm). A stepwise etching process should be adopted to reduce line width deviation.
▶ 2. Lamination and Warpage Control
The coefficient of thermal expansion (CTE) of thick copper layers differs significantly from that of the substrate. When laminating, a "symmetrical structure" (consistent copper thickness between upper and lower layers) should be adopted, and a rigid support layer should be added to prevent PCB warping (warping degree ≤0.5%).
▶ 3. Surface Treatment
The surface of thick copper is prone to oxidation. It is preferred to choose tin plating (high-temperature tin layer) or nickel-gold plating to avoid OSP (incomplete organic film coverage).
The pad area needs to be enlarged with a "solder mask opening window" to ensure the bonding force between the 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, problems such as thick copper etching and lamination warping need to be solved. They are suitable for high-power and high-current industrial and energy scenarios.
