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Understanding Coin Insertion in PCBs: Design, Materials, and Benefits

embbed copper coin-feature

As power electronics continue to evolve toward higher current density, compact layouts, and improved thermal performance, traditional PCB heat dissipation techniques sometimes reach their limits. Engineers designing power converters, automotive electronics, and high-current control systems often face the challenge of removing heat efficiently from critical components such as MOSFETs, IGBTs, and power ICs.

One advanced thermal solution that has gained popularity in recent years is coin insertion technology in printed circuit boards (PCBs). By embedding solid copper “coins” directly into the PCB structure, designers can create localized heat-spreading and high-current conduction paths that significantly improve system reliability.

This article explains coin insertion PCB technology, including its design principles, materials, manufacturing process, benefits, applications, and cost considerations in 2026. It also provides practical insights for engineers selecting a coin insertion PCB manufacturer for high-power electronic applications.

1. What Is Coin Insertion in a PCB?

Coin insertion PCB technology refers to a manufacturing technique where solid copper coins (thick copper inserts) are embedded into a printed circuit board during fabrication.

These copper coins act as thermal and electrical conductors, transferring heat away from power components and distributing current more efficiently.

Basic Structure of a Coin Inserted PCB

A typical coin insertion PCB consists of:

  • Standard PCB substrate (FR-4 or high-TG laminate)
  • Precisely machined copper coins
  • Routed cavities in the PCB
  • Laminated layers surrounding the coin
  • Copper plating to integrate electrical connections

The inserted copper coin often sits directly beneath high-power semiconductor packages, creating a low thermal resistance path to heatsinks or chassis structures.

2. How Coin Insertion Technology Works

Coin insertion technology works by reducing thermal resistance and improving current flow within high-power circuit regions.

Thermal Conduction Principle

Copper has a thermal conductivity of approximately:

~400 W/m·K

Compared to FR-4 material:

~0.3–0.4 W/m·K

By inserting a copper coin under a heat source, heat can move quickly through the copper and dissipate into surrounding copper planes or external heatsinks.

Electrical Performance Improvement

Copper coins also help with:

  • High current distribution
  • Reduced copper trace resistance
  • Improved power module reliability

This makes coin insertion particularly suitable for power supply PCBs and high-current industrial electronics.

3. Materials Used in Coin Insertion PCBs

The choice of materials significantly affects thermal performance, manufacturability, and cost.

Copper Coins

Most commonly used materials include:

  • Pure copper (C1100 or equivalent)
  • High conductivity copper alloys

Typical coin thickness ranges from: 1 mm to 6 mm

depending on thermal requirements.

PCB Substrate Materials

Common PCB laminates include:

  • FR-4 high-TG materials
  • High reliability laminates for automotive electronics
  • Low-loss materials for high-frequency power circuits

Surface Finishes

Typical surface finishes used in coin insertion PCBs include:

  • ENIG (Electroless Nickel Immersion Gold)
  • Immersion tin
  • OSP (Organic Solderability Preservative)

4. Coin Insertion PCB Manufacturing Process

The coin insertion PCB fabrication process requires precise mechanical and lamination techniques.

Step 1: Coin Machining

Copper coins are:

  • CNC machined
  • Ground to exact thickness
  • Cleaned for bonding

Step 2: PCB Cavity Routing

The PCB core or multilayer stack is precision routed to create cavities where the coin will be inserted.

Step 3: Coin Placement

The copper coin is placed into the cavity with tight mechanical tolerances.

Step 4: Lamination

PCB layers are laminated together under high pressure and temperature, integrating the coin into the board structure.

Step 5: Plating and Finishing

Finally:

  • Copper plating connects the coin to circuit layers
  • Surface finishes are applied
  • Electrical testing ensures reliability

This process requires advanced PCB fabrication expertise and tight dimensional control.

5. Design Guidelines for Coin Insertion PCBs

Designing a reliable coin insertion PCB for high-power electronics requires careful planning.

Placement Strategy

Coins should be placed:

  • Directly beneath heat-generating components
  • Near MOSFETs, IGBTs, or power regulators
  • Under large thermal pads

Coin Thickness

Typical thickness options:

Power Level Coin Thickness
Medium Power 1–2 mm
High Power 3–4 mm
Extreme Power 5–6 mm

Thermal Simulation

Before manufacturing, engineers should run:

  • Thermal simulations
  • Current density analysis
  • Mechanical stress testing

This ensures the coin insertion design will perform as expected.

6. Thermal and Electrical Benefits of Coin Insertion Technology

Coin insertion technology provides several advantages compared with conventional PCB thermal solutions.

Improved Heat Dissipation

Copper coins create a direct heat transfer path, reducing hotspot temperatures significantly.

Higher Current Carrying Capacity

Thick copper inserts support large current flows without overheating.

Reduced Thermal Resistance

Thermal resistance can be reduced by 30–70% compared to standard PCB structures.

Increased System Reliability

Better thermal management leads to:

  • Longer component lifespan
  • Reduced failure rates
  • Improved system stability

7. Applications of Coin Insertion PCBs

Coin insertion PCBs are widely used in high-power electronic systems.

Power Electronics

Examples include:

  • DC-DC converters
  • Power supply modules
  • Voltage regulators

Automotive Electronics

Electric vehicles and advanced automotive electronics often require efficient thermal solutions.

Applications include:

  • Motor controllers
  • Battery management systems
  • Inverters

Industrial Equipment

Industrial electronics frequently rely on coin insertion PCBs for:

  • Motor drivers
  • Power control units
  • Industrial automation equipment

LED Power Systems

High-power LED drivers also benefit from improved heat dissipation.

8. Coin Insertion PCB vs Other Thermal Solutions

Understanding alternatives helps engineers choose the best solution.

Coin Insertion vs Heavy Copper PCB

Heavy copper boards increase copper thickness across the entire PCB, while coin insertion provides localized heat dissipation.

Coin Insertion vs Metal Core PCB

Metal core PCBs provide overall heat spreading, but coin insertion targets specific hotspots.

Coin Insertion vs Thermal Vias

Thermal vias transfer heat through the board but have higher thermal resistance compared with solid copper coins.

For extreme power density designs, coin insertion is often the most efficient solution.

9. Design Challenges and Limitations

Despite its advantages, coin insertion PCB technology also presents challenges.

Manufacturing Complexity

Precise machining and lamination processes increase fabrication difficulty.

Mechanical Stress

Differences in material expansion between copper and laminate can create stress during thermal cycling.

Cost Considerations

Coin insertion boards are typically more expensive than standard PCBs.

However, the improved reliability often justifies the additional cost in high-power systems.

10. Coin Insertion PCB Cost Factors in 2026

The cost of manufacturing a coin insertion PCB depends on several factors.

Key Pricing Factors

  • Copper coin size and thickness
  • PCB layer count
  • Board size
  • Thermal design complexity
  • Production volume

Typical Coin Insertion PCB Prices in 2026

Approximate market prices:

PCB Type Estimated Price (USD)
Prototype Coin Insertion PCB $120 – $450 per board
Small Batch Production $35 – $120 per board
Mass Production $8 – $40 per board

Large-scale orders significantly reduce per-unit costs.

11. Choosing the Right Coin Insertion PCB Manufacturer

Not every PCB supplier can produce reliable coin insertion PCBs for high-power electronics.

Key capabilities to evaluate include:

  • Precision CNC coin machining
  • Advanced multilayer lamination technology
  • Thermal design support
  • High-current PCB manufacturing experience

Manufacturers such as KingsunPCB specialize in advanced PCB fabrication technologies, including coin insertion PCBs, heavy copper boards, high-current designs, and high-reliability multilayer PCBs.

With extensive experience in power electronics, automotive systems, and industrial applications, KingsunPCB provides engineering support from prototype development to mass production, helping customers optimize thermal performance and manufacturing efficiency.

12. Future Trends in Coin Insertion PCB Technology

As electronics continue to evolve, coin insertion technology will play a larger role in thermal management.

Emerging Trends

  • Higher power density electronics
  • Electric vehicle power modules
  • Advanced semiconductor packaging
  • Integrated thermal management PCB designs

Future designs may also combine coin insertion with heavy copper layers and advanced cooling technologies.

13. Frequently Asked Questions (FAQ)

Q1: What is the purpose of coin insertion in PCB design?

Coin insertion improves thermal performance and current handling by embedding solid copper into the PCB structure.

Q2: When should engineers use coin insertion PCBs?

Coin insertion PCBs are ideal for:

  • High-power electronics
  • Power modules
  • Automotive power control systems
  • High-current industrial circuits

Q3: How thick are copper coins in PCBs?

Typical thickness ranges from 1 mm to 6 mm, depending on the power requirements.

Q4: Are coin insertion PCBs expensive?

They are more expensive than standard PCBs, but their thermal performance and reliability advantages often outweigh the cost.

14. Conclusion

As modern electronics continue to demand higher power density and improved thermal management, coin insertion PCB technology has become an important solution for engineers designing high-current and high-power systems.

By embedding copper coins directly into the PCB structure, designers can achieve excellent heat dissipation, reduced thermal resistance, and improved electrical performance. These benefits make coin insertion PCBs widely used in power electronics, automotive systems, industrial equipment, and LED drivers.

With proper design guidelines, careful material selection, and collaboration with experienced manufacturers such as KingsunPCB, engineers can successfully implement coin insertion PCB solutions that deliver both performance and long-term reliability.

As thermal challenges continue to grow in advanced electronics, coin insertion technology will remain a key innovation in next-generation PCB manufacturing.