The copper weight of a PCB refers to the thickness of the copper foil laminated onto the substrate. It is usually expressed in ounces per square foot (oz/ft²) — representing the weight of copper distributed over one square foot of area.
Common copper weights include:
• 1 oz/ft² (≈ 35 μm / 300 g/m²)
• 2 oz/ft² (≈ 70 μm / 600 g/m²)
• 3 oz/ft² (≈ 105 μm / 900 g/m²)
At PCBasic, we provide a wide range of copper thickness options to meet diverse design requirements.
• Outer layer copper thickness: from 1 oz up to 13 oz
• Inner layer default copper thickness: 1 oz
Using heavier copper enhances the current-carrying capacity and thermal performance of the PCB, making it suitable for power electronics, automotive, and industrial control applications. However, it also increases the etching difficulty and production cost, so for most standard electronic circuits, 1 oz copper is typically sufficient.
When preparing for mass production, please make sure that your PCB design’s minimum trace width and spacing comply with PCBasic’s manufacturing specifications to ensure high yield and precision during fabrication.
The Min Track/Spacing for Outer Layer (Before Compensation)
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Copper Weight
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Normal Process
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Medium Difficulty
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High Difficulty
|
|
1 oz
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≥ 5/6 mil
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≥ 5/5 mil
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< 4/4 mil
|
|
2 oz
|
≥ 7/8 mil
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≥ 6/7 mil
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< 5/6 mil
|
|
3 oz
|
≥ 10/12 mil
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≥ 8/10 mil
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< 6/9 mil
|
The Min Track/Spacing for Inner Layer (Before Compensation)
|
Copper Weight
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Normal Process
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Medium Difficulty
|
High Difficulty
|
|
1 oz
|
≥ 4/5 mil
|
≥ 4/4 mil
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< 3.5/4 mil
|
|
2 oz
|
≥ 6/8 mil
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≥ 6/7 mil
|
< 5/6 mil
|
|
3 oz
|
≥ 8/11 mil
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≥ 8/10 mil
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< 6/9 mil
|
