Essential Tips for Designing Heavy Copper PCBs for High Current

Heavy copper PCBs are important for high-power systems. They manage strong electrical currents and resist heat and damage. Many industries use them for key tasks like power supplies and electric cars. Good designs lower the chance of problems and handle heat well. This makes them dependable in tough conditions.

Key Takeaways

• Heavy copper PCBs are important for high-power devices. They carry big currents and handle heat well, making them strong in hard conditions.
• Picking the right copper thickness is very important. Thicker copper carries more current, handles heat better, and is stronger.
• Using thermal vias and heat sinks helps control heat in heavy copper PCBs. Placing parts in the right spots stops them from overheating.

Understanding Heavy Copper PCBs

What Defines a Heavy Copper PCB

Heavy copper PCBs are special because they handle high current and heat. They have copper layers that are 3oz thick or more. This makes them great for tough jobs. Thicker copper helps carry more current and spread heat better. This ensures they work well in high-power systems.

Criteria	Description
Copper Thickness	Heavy copper PCBs have copper layers 3oz thick or more.
Current Carrying Capacity	They carry large currents, reducing heat and stress.
Thermal Conductivity	Copper spreads heat well (401W/mK), keeping systems cool.
Application Suitability	Used in defense, aerospace, and power systems for high-current needs.

Key Advantages of Heavy Copper PCBs

Heavy copper PCBs have many benefits for high-current systems. They carry large electrical loads without overheating. Thicker copper spreads heat better, making them reliable and safe. These PCBs are also strong, so they last in tough conditions.

Advantage	Description
Increased Current Carrying Capacity	Thicker copper layers help carry more current for high-power tasks.
Improved Thermal Management	Thicker copper spreads heat, preventing overheating and damage.
Enhanced Mechanical Strength	Extra copper makes them strong and able to handle stress.
Extended Lifespan	These features make them last longer and need less fixing.

Applications in High-Power Electronics

Heavy copper PCBs are used in many high-power devices. For example, motor control systems use them to handle heavy electrical loads. Flexible PCBs with thick copper are great for power electronics, military tools, and electric cars. They are also key in medical devices and automation systems where reliability is critical.

• Comparison: 1 oz vs. 2 oz Copper Thickness
• 1 oz.: Works for small to medium power needs.
• 2 oz.: Handles heat and heavy loads better.
• Application: Motor Control Systems
• 1 oz. Copper Thickness: Good for small power but struggles with big loads.
• 2 oz. Copper Thickness: Manages heat and works well for heavy power needs.
• Application: Flexible Printed Circuit Boards
• Properties: Carries more current and spreads heat well.
• Use Cases: Perfect for power electronics, military tools, medical devices, automation, and electric cars.

Essential Design Considerations for Heavy Copper PCBs

Choosing the Right Copper Thickness

Picking the right copper thickness is very important. Thicker copper improves how much current the PCB can handle. It also helps with heat control and makes the PCB stronger. Thicker copper lowers resistance, which is great for high-frequency uses.

Here are key points to think about when choosing copper thickness:

• High Current Handling: Thick copper carries more current without overheating.
• Improved Thermal Management: More copper spreads heat better, keeping parts cool.
• Enhanced Mechanical Strength: Thick copper makes the PCB tougher and more durable.
• Reduced Impedance: Extra copper lowers resistance, helping in high-current designs.
• Increased Reliability: Thicker copper lasts longer and works better over time.
• Design Flexibility: It allows complex layouts and supports higher currents.

Engineers use tools like ANSYS and SolidWorks PCB to plan copper thickness. The IPC-2152 standard also helps decide trace size based on current and heat rise.

Tip: Balance copper thickness with how easy it is to make the PCB.

Calculating Trace Widths for High Current

Trace width is important for handling high current safely. The IPC-2221 standard gives a formula to calculate trace width based on current and heat rise:

I = k × (ΔT^0.44) × W^1.0 × t^0.725

Where:

• I: Current in Amps
• ΔT: Allowed temperature rise in °C
• W: Trace width in mils
• t: Copper thickness in oz/ft²
• k: A constant based on copper thickness

This formula helps figure out the right trace width for high current. Online tools make it easier by letting you enter current, heat rise, and copper thickness.

Note: Outer traces need less width than inner ones because they cool faster. Always check IPC standards for exact rules.

Handling Thermal Expansion and Stress

Heat expansion can weaken heavy copper PCBs in high-power systems. Matching copper and material expansion rates reduces stress from heat changes.

Evidence Description	Key Points
CTE Matching Importance	Matching copper and material expansion rates lowers stress.
High Aspect Ratio Vias	Thick plating helps reduce stress in tall vias.
Glass Transition Temperature	Materials expand more above their Tg, causing extra stress.
Stability of CTE	Stable expansion rates close to copper’s are best for heat cycles.

To handle heat stress well:

• Pick materials with steady expansion rates.
• Avoid tall vias unless reinforced with thick plating.
• Use materials with a Tg that fits your needs.

Tip: Add thermal vias and heat sinks to spread heat and lower stress.

Ensuring Manufacturability with LTPCBA‘s Help

Working with LTPCBA ensures your PCB designs are easy to make and high quality. They offer full services and quick feedback to improve the design process.

Advantage	Description
Timely Updates	Fast feedback on your PCB design progress.
Comprehensive In-House Services	Full PCB assembly services for better results.
High-Quality Standards	Reliable quality in prototypes and production.
Quick Project Turnaround Times	Projects finished fast, saving time and money.

With LTPCBA, you get advanced tools to meet industry needs. Their focus on quality and innovation makes them a great choice for heavy copper PCBs.

Callout: Visit LTPCBA‘s website to learn more about their services.

Best Practices for Thermal Management in Heavy Copper PCBs

Using Thermal Vias for Heat Dissipation

Thermal vias help remove heat in heavy copper PCBs. They let heat move easily from the top layer to the bottom. This keeps parts cool and prevents overheating. Place thermal vias under hot components for better cooling. Adding more vias improves heat removal but needs careful planning for space.

Factor	Description
Thermal Via Sizes	Vias should be 0.2mm to 0.4mm wide for good heat flow.
Placement	Put vias under hot parts to transfer heat well.
Number of Vias	More vias help cooling but need space in the layout.

• Thermal vias give heat a quick way to escape.
• They work best when placed under hot components.

Tip: Combine thermal vias with other cooling methods for better results.

Choosing High Thermal Conductivity Materials

Using materials that spread heat well is very important. These materials keep the PCB cool and safe. Copper layers in heavy copper PCBs act like heat sinks. They quickly move heat away from hot spots, protecting parts from damage.

Metal Core PCBs (MCPCBs) are great for high-heat uses. They have a metal core, like aluminum or copper, which spreads heat better than regular FR4. Copper-based MCPCBs are even better than aluminum ones for heavy current tasks.

Note: High thermal conductivity materials make PCBs last longer by stopping overheating.

Strategic Placement of High-Power Components

Where you place high-power parts affects cooling. Keep these parts away from sensitive areas to avoid heat problems. Don’t group hot parts together, as this creates heat spots.

Spread out high-power parts like processors and FPGAs. This helps heat spread evenly and avoids buildup. Align these parts with thermal vias or metal bases for better cooling. Good placement keeps your PCB cool and working well.

Tip: Plan where to put parts early to avoid heat issues later.

Incorporating Heat Sinks and Thermal Pads

Heat sinks and thermal pads are key for cooling heavy copper PCBs. Heat sinks move heat from the PCB to the air. Their design and material affect how well they work. Thermal pads improve the connection between parts and heat sinks for better heat transfer.

You can measure heat sink performance with this formula:

Tj = Ta + (Rja × Power dissipated)

Where:

• Tj: Highest temperature of the part
• Ta: Air temperature around the PCB
• Rja: Resistance to heat flow from part to air

This formula helps check if your PCB stays cool enough. Use heat sinks and pads to keep your PCB running well and lasting longer.

Callout: Pick heat sinks and pads that fit your PCB’s cooling needs for the best results.

Advanced Techniques for High-Current Applications

Using Copper Busbars for Better Current Flow

Copper busbars help move high current efficiently in PCBs. They are strong and handle electrical loads well. Their design lowers inductance, cutting voltage spikes and noise. This keeps systems stable in high-power setups. Copper busbars carry large currents because of their size and quality materials. They also spread heat well, keeping parts cool and reducing the need for extra cooling. Their strength makes them last longer and resist damage from vibration.

Advantage	Description
Lower Inductance	Reduces voltage spikes and noise by improving current flow.
High Current Capacity	Handles large currents due to its size and material quality.
Better Heat Management	Spreads heat well, keeping parts cool and lowering cooling needs.
Strong and Durable	Resists wear and vibration, making it reliable for tough tasks.

Tip: Add copper busbars to your PCB for better current flow and cooling.

Adding Terminal Blocks for Strong Connections

Terminal blocks make high-power connections easier in PCBs. They provide a safe way to connect wires and parts. To use them well:

1. Install them properly for better performance in high-current tasks.
2. Pick terminal blocks that fit your project’s needs.
3. Use tools and examples to design and install them correctly.

Terminal blocks are great for projects needing strong and reliable connections. They work well in many high-current applications.

Callout: Pick the right terminal blocks to improve your PCB’s reliability.

Multi-Layer Heavy Copper PCBs for More Power

Multi-layer heavy copper PCBs are great for handling high current. They stack copper layers to improve current flow and heat control. Each layer helps spread current evenly and keeps parts cool. These designs also allow for more complex layouts, so you can add powerful parts without losing performance. Multi-layer PCBs are strong and reliable, making them perfect for tough jobs like electric cars and factory machines.

Note: Multi-layer designs give you more options for high-current systems.

Why Choose LTPCBA for Heavy Copper PCB Solutions

Expertise in High-Quality PCB Manufacturing

LTPCBA has over 15 years of PCB experience. Since 2008, they’ve earned a strong reputation for quality. They serve customers worldwide, including the USA, Canada, Germany, and France. Their certifications meet IPC 610 Class 2 and Class 3 standards, proving their commitment to excellence.

Evidence Type	Details
Established Year	Started in 2008
Industry Experience	Over 15 years making PCBs
Global Reach	Trusted by customers in the USA, Canada, Germany, and France.
Quality Control Certifications	Certified to meet strict IPC 610 Class 2 and Class 3 standards.
Service Offerings	Full service from design to assembly.
Customer Orientation	Focused on helping customers and ensuring satisfaction.
Investment in Quality	Invests in top equipment and skilled workers for quality.
Compliance Standards	Meets high industry standards for reliable production.

Their expertise ensures your heavy copper PCBs are reliable and high-performing.

Customization Options for High-Current Applications

LTPCBA knows every project is different. They let you customize heavy copper PCBs for your needs. Options include copper thickness, solder mask colors, and finishes like ENIG or HASL. These choices help create PCBs that work perfectly for your project.

Tip: Share your project details with LTPCBA to find the best customization options.

Commitment to Innovation and Reliability

LTPCBA focuses on innovation and reliability. They use advanced tools and skilled workers to stay ahead. This ensures you get modern solutions for high-current needs. Their PCBs are dependable, even in tough conditions.

Choosing LTPCBA means partnering with experts who support your high-power projects.

Making heavy copper PCBs needs focus on copper thickness, trace size, and heat control. These factors must be optimized for strong and lasting performance.

Design Advice	Explanation
Trace size for current flow	Use the rule: 500 circular mils per amp. For 5A, a 2oz copper trace should be 20 mils wide.
Handling heat expansion	Control heat effects to avoid pad damage, board splitting, or bending.

Balancing these with easy manufacturing leads to sturdy designs. Work with LTPCBA for expert help with high-power projects.

FAQ

What is the thickest copper used in heavy copper PCBs?

Heavy copper PCBs can have copper layers as thick as 20 oz/ft². The exact thickness depends on your design needs and what your PCB maker can handle.

How can you find the right trace width for high current?

You can use the IPC-2221 formula or online tools. Enter the current, copper thickness, and temperature rise to get the correct trace width for your design.

Why pick LTPCBA for heavy copper PCBs?

LTPCBA provides top-quality manufacturing, custom options, and expert help. Their advanced tools create reliable solutions for high-power and high-current projects.

Tip: Reach out to LTPCBA for advice on your heavy copper PCB design.