Enter your Outer Pad Diameter, Inner Diameter, Spoke Width, Number of Spokes, Copper Weight, Plane Area, Max Current, and Ambient Temperature to calculate your pad's Thermal Resistance, Current Capacity, Solderability Rating, and Max Temperature.
Thermal Resistance
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Current Capacity
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Solderability Rating
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Maximum Temperature
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Not necessarily. High-current connections may need direct plane connection for maximum current carrying capacity, while signal pins typically benefit from thermal relief for better solderability.
Thermal reliefs slightly increase resistance and inductance compared to direct connections, but the impact is minimal for most applications. The improved solderability usually outweighs these small electrical compromises.
Wave soldering typically requires more aggressive thermal relief (fewer or narrower spokes) due to longer heat exposure times. Reflow soldering can often use less aggressive relief patterns.
Yes, you can optimize spoke widths per layer based on current requirements and thermal management needs. Inner layers often need wider spokes due to reduced heat dissipation.
Four spokes provide the best balance for most applications. Two spokes offer maximum thermal isolation but reduced mechanical strength, while six or eight spokes provide better current capacity but reduced thermal benefit.
Heavier copper (2oz+) conducts heat more effectively, requiring more aggressive thermal relief patterns. Lighter copper (0.5oz) may need less aggressive relief but has lower current carrying capacity.
Direct ground plane connections act as massive heat sinks, making it difficult to reach solder melting temperatures during assembly. This often results in cold solder joints and manufacturing defects.