Famous Heavy Copper PCB from China Suppliers - Durable, High-Performance Components for Power Converters and Vehicles Supplier, Companies
Product Description
What is Heavy Copper PCB?
Core Features and Application Scenarios
Key Design Points
Selection of Copper Foil Thickness
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 to 4 oz of copper should be preferred. For ultra-power scenarios (≥20A), 6 to 12 oz of copper should be selected.
Trace and Current-Carrying Capacity Design
Current-carrying capacity calculation: Thick copper trace needs to be combined with 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℃).
Trace optimization: For high-current traces, keep them as short and wide as possible to avoid narrow necks. Multi-layer boards can adopt "parallel connection of multiple copper layers" (e.g., 2 layers of 2 oz copper ≡ 4 oz) to enhance current-carrying capacity.
Via and Pad Design
Vias: For high-current vias, increase hole diameter (≥0.5mm), increase number of vias (estimated at 1A per hole), and copper plating thickness on hole wall should be ≥20μm (vs. 8–12μm for ordinary PCBs).
Pads: Thick copper pads need to be enlarged in size (0.2–0.5mm larger than ordinary pads) to prevent the copper layer from dissipating heat too quickly during welding, which may lead to false soldering.
Heat Dissipation and Insulation Design
Heat dissipation: 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.
Insulation: Wire spacing for thick copper layers should be widened (for 70μm copper, spacing should be ≥0.2mm) to prevent creepage breakdown under high voltage.
Manufacturing Process Difficulties and Control
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 (~1μm/min). 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.
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.
