Ask Me Anything about High-Current PCBs

Join our next Ask Me Anything about high-current PCBs where you can ask us questions on:

• Trace design
• Thermal management
• Copper weight
• And much more!

commentcloud.png Post your questions below before September 25th!

Are there specific materials or dielectrics recommended for high-current PCBs?

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What are your considerations for multilayer stackups in high current boards for safe current distribution?

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What are the best practices for calculating the trace width for high-current applications? Do you have any tools?

For example, consider a PCB designed for a power amplifier circuit drawing 10A of current. The board uses copper with a thickness of 1 oz/ft² (35 micrometers). How can you ensure the traces can handle this high current without excessive heat generation or voltage drop?

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Hello

We have this calculator which can help you identify the trace width requirement for the you specification, its easy to use. kindly check

https://www.protoexpress.com/tools/trace-width-and-current-capacity-calculator/

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Hello Isha,

For high-current applications, knowing current carrying capacity of the traces and the Vias on the path of the High current is important and designing them as per the current and temperature requirements is necessary. Using heavy copper layers is also recommended.

High Temp FR4, Teflon (PTFE), Polyimide have good thermal and electrical properties making them good for high current applications.
some of the material properties that you should look for High Thermal conductivity, good Dielectric Electrical Strength, CAF Resistance.

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Hello Thorme,

When designing multilayer PCBs for high-current applications, it’s crucial to optimize the stackup to ensure safe and efficient current distribution. Here are some key considerations:

Dedicated Ground and power plane, Having multiple ground planes to have an easy return path.

Use thicker Copper Layers to reduce resistance and improve current carrying capacity of the traces.

Choose Material with good thermal and electrical properties for better thermal management.

Any guidelines for high current trace and copper layer ounces (approximate numbers or range)?

What are the ultimate materials (price no consideration) for the robust, long lasting, radiation hard resistant for PCB material selection?
Is materials same or different for High current power boards and Processor controller/communication board?

The general guidelines are covered here Trace Width, Current Capacity and Temperature Rise Calculator

Beyond that it becomes very difficult to say since there are so many unique designs. But, you have to start somewhere. Until you get to the point the board is too stiff, too heavy, or too thick, more copper is better copper. One thing many people seem to forget about is the old-school answer, Buss Bars. PCB mounted buss bars can fulfill many applications, are low in cost and can deliver some pretty impressive performance.

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Standards that space-grade PCBs must meet include IPC-A-610E Class 3, which requires high-performance electronic devices to operate continuously in critical conditions.

You wouldn’t necessarily use the same materials in a PCB bound for space as you would in one for use in the home, manufacturing or transportation. They have to withstand extreme polarizing temperatures, immense pressure and vacuums, zero gravity, vibrations, impacts and more.

  • High-performance substrates are frequently used such as ceramic or polyimide, which can withstand extremely harsh conditions. Alumina is the most common.
  • Copper is just as useful in space as it is on Earth thanks to its light weight and high conductivity.
  • Fiberglass-reinforced epoxy is commonly used due to its durability and weight. For a long time single-sided boards were used for reliability.
  • The solder mask must have high thermal stability so it can endure hot and cold temperatures and not risk short circuits.
  • Gold is often used on satellite PCBs as a durable surface finish due to it being corrosion-resistant and having great conductivity.
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Rogers materials are Robust and are specifically designed to work at microwave and RF spectrum in Space environments with high radiation and vacuum.

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