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Why Choose PCBMay for Copper Coin PCBs?
- Space-saving thermal solution: We embed copper coins directly into PCBs to reduce reliance on bulky external heat sinks. This makes your design more compact while also improving heat dissipation.
- Direct thermal path: With precision copper embedding and lamination processes, we form stable heat conduction paths right under heat-generating components to improve thermal transfer efficiency.
- Localized high-current path: We support copper coin structures in high-current areas to meet the dual requirements of current-carrying capacity and heat dissipation in high-power applications.
- Better cooling performance than via farms: Compared to the via-farm solution, our copper coin process provides a more direct thermal conduction path.
- Direct thermal connection to heat sink: We provide efficient thermal bonding solutions for copper coin, external heat sinks, embedded busbars, and other components, helping improve overall thermal management in your project.
What is Copper Coin PCB?
These PCBs with embed solid copper inserts directly into the substrate. These copper coins sit inside cut-out areas of the PCB and connect to copper planes. You use this structure when standard copper thickness cannot handle heat. It is common in high-power designs where thermal control is critical.
Unlike standard multilayer boards, copper coin designs focus on localized heat transfer. Embedded copper acts as a thermal path. It pulls heat away from hot components and spreads it across the board or into a heatsink. This reduces thermal resistance and keeps sensitive parts stable during operation.
The main benefit is efficient heat removal. You place the copper coin exactly under high-power devices like MOSFETs or LEDs. Heat moves faster through solid copper than through dielectric layers. By utilizing precision CNC routing and specialized bonding processes, PCBMay support your high-power copper coin PCB projects. Just send us your Gerber file today to get your free DFM review and quote.
Copper Coin PCB Types
Copper coin PCBs come in various structural designs with distinct heat conduction performance. They can be classified by copper coin position and installation method. According to structure and assembly, they can be divided into the following types:
This design places the copper coin fully inside the board. It stays flush with the surface, so assembly remains simple. The structure keeps the layout clean while heat moves directly into the copper.
The copper coin sits within the inner layers and does not reach the outer surface. This setup works well when heat builds up inside the stack. The coin spreads that heat across the board without affecting the outer layout.
This type positions the coin partly inside and partly exposed. One side connects to the component, while the other ties into inner layers. It provides a balance between surface cooling and internal heat distribution.
The copper coin runs through the full thickness of the board. It connects the top and bottom layers directly. This structure supports strong heat transfer and improved current flow in a single path.
The copper coin is fixed during lamination and becomes fully integrated into the PCB structure. This creates a stable thermal path and strong mechanical bonding.
The copper coin is inserted into a precisely machined cavity with tight pressure fit. Direct contact with surrounding material enables fast heat transfer from hot components.
PCBMay Service Advantage for Your Copper Coin PCB
PCBMay provides complete support for copper coin PCB projects, from initial DFM review to final validation. Every step is controlled to ensure stable thermal performance, strong copper bonding, and long-term mechanical reliability in high-power designs.
Our engineering team reviews coin size, placement, and stack-up before production to help you reduce fabrication risk and improve manufacturability.
We support stable copper coin PCB production from prototype to volume manufacturing, helping keep thermal performance and quality consistent.
We can manufacture copper coins in different shapes and sizes to match your component layout, thermal needs, and board structure.
Each board goes through AOI, X-ray inspection, and additional checks for internal structure. These steps confirm proper coin placement, layer bonding, and internal alignment.
Copper Coin PCB Applications
Copper coin PCBs are used where heat becomes a real limit. When standard copper layers cannot move heat fast enough, this structure adds a direct thermal path. It keeps components cooler, improves stability, and extends product life.
Used to manage heat from baseband processors and RF modules. The copper coin pulls heat away from hot spots, helping maintain stable signal performance in compact layouts.
Applied in battery management systems, motor drives, and onboard chargers. These systems generate constant heat, and the copper coin helps keep temperatures within safe limits during operation.
Common in converters and inverters that handle high current. The copper coin supports both heat dissipation and current flow, improving efficiency and reducing thermal stress on the board.
Used in high-brightness LED modules where space is tight. The copper coin sits under the LED to draw heat away quickly, helping maintain brightness and extending LED lifespan.
Copper Coin PCB Case Studies
To demonstrate PCBMay’s capabilities in thermal management and high-power PCB fabrication, we have compiled two recent case studies. These examples highlight PCBMay’s precision in embedding copper coin structures to support high-current loads and critical heat dissipation requirements.
PCBMay fabricated a 4-layer PCB designed for Electric Vehicle (EV) energy storage. To address the high thermal load of power conversion, we integrated a 2.0mm thick copper coin directly into the stack-up. The use of Shengyi S1000-2 (High-Tg) provides the necessary thermal stability to prevent delamination during high-temperature operation. This construction ensures a low-resistance thermal path and high-current capacity, meeting the rigorous durability standards of EV power electronics.
Technical Specifications:
- Material: Shengyi S1000-2
- Layer Count: 4 Layers
- Board Thickness: 2.0 mm
- Copper Weight: 1 oz (All layers) + 2.0mm integrated copper coin
- Board Size: 400 × 45 mm
- Surface Finish: Immersion Gold (ENIG) (2 U”)
- Application: EV Energy Storage Systems
- Key Features: High-Tg thermal stability, ultra-high current carrying capacity, and robust copper-to-substrate bonding.
PCBMay manufactured a 6-layer, 3.20 mm thick PCB for new energy power infrastructure. The design required a built-in 12.0mm copper coin to manage extreme thermal dissipation. Utilizing a precise depth control routing process, we embedded the copper coin to ensure flush contact with power components. This multilayer structure supports heavy-current bearing while maintaining mechanical stability, specifically engineered for long-term reliability in high-voltage industrial environments.
Technical Specifications:
- Material: Shengyi S1000-2
- Layer Count: 6 Layers
- Board Thickness: 3.20 mm
- Copper Weight: 1 oz (All layers) + 12.0mm built-in copper coin
- Board Size: 280 × 60 mm
- Surface Finish: Immersion Gold (ENIG) (2 U”)
- Application: High-Power New Energy Infrastructure
- Key Features: Accurate depth control, high thermal resistance, and optimized current density for thick-board power structures.
More About PCBMay
These are our capabilities, watch related videos, and view factory images.
- Multilayer PCB Process Capabilities
- Video
- Gallery
| Process Category | PCBMay Capability Range |
| Layer Count | 1–40 Layers |
| Material Types | FR-4 (High-Tg), Rogers, Arlon, Nelco, Polyimide |
| Copper Weight | Up to 100 oz |
| Copper Coin Types | Embedded, Press-fit, or Bonded Copper Coins |
| Drilling Precision | Minimum Mechanical Drill: 0.15mm (6 mil) Laser Drill (Blind/Buried): 0.1mm (4 mil) |
| Routing Tolerance | CNC Depth Control: ±0.05mm Outline Tolerance: ±0.1mm |
| Surface Finish | Copper Coin PCBs commonly require ENIG. |
| Registration | ±0.075mm (3 mil) |
| Quality Standards | IPC Class 2 and IPC Class 3 |
Testimonials
We used PCBMay’s copper coin boards for a demanding EV control module, and the thermal performance was a significant upgrade over standard designs. The boards remained structurally stable throughout our repeated thermal cycling tests, and the assembly process was very efficient. PCBMay delivered exactly what we needed for high-power automotive reliability.
Elena RodriguezAutomotive Systems DesignerFor our high-power LED modules, PCBMay’s copper coin integration solved our heat dissipation issues. We no longer see thermal hotspots, and our LED brightness remains stable during long-term operation. The precision of their cavity machining and coin fitting is excellent, making PCBMay a reliable partner for our high-power projects.
Mark De CastroPower Electronics Engineer
Related Product
A PCB built with a metal base layer, usually aluminum or copper. It helps move heat away from power components and keeps temperature stable in high-load circuits.
High-performance boards with thickened copper layers designed for superior heat dissipation and maximum current-carrying capacity in demanding power applications.
A PCB used in vehicle electronics. It is built to handle vibration, heat changes, and long operating hours in systems like engine control and safety modules.
A board designed for fast signal transmission. It reduces signal loss and interference, making it suitable for RF, 5G, and communication systems.
What is Copper Coin Technology?
Copper coin technology is applied when heat begins to affect board performance. A solid copper insert is embedded into the PCB, positioned under high-power components. Heat transfers into the copper and spreads quickly. Copper offers high thermal conductivity while maintaining strong electrical performance. This makes it suitable for power electronics, automotive systems, and telecom boards, where stable temperature control is required.
Embedded copper technology creates a direct heat path within the PCB layers. Solid copper is integrated close to critical components, which reduces thermal resistance. Compared to aluminum or ceramic materials, copper transfers both heat and current more efficiently. This results in a cooler and more stable board, especially in applications with strict thermal limits.
When is Copper Coin Best to Use?
Copper coin works best when a few components generate most of the heat. In these cases, heat is not spread out. It is concentrated in small areas. A copper coin targets these hot spots directly. It is press-fit into a cutout under the component. Heat then moves straight through the copper and into a heat sink. This path avoids the PCB base materials, which often slow heat flow. As a result, thermal resistance drops, and cooling improves.
The copper coin can take different forms inside the PCB. Its position depends on layout needs. Routing space, power planes, and distance to the component all matter. A closer position gives better heat transfer, but it may affect routing flexibility. The final setup reflects this balance.
How do Copper Coin PCBs Work?
The concept is simple. A solid copper slug sits under the heat source, such as a power IC, MOSFET, LED, or BGA. It can stay flush with the PCB surface or extend slightly to touch a heat sink or chassis. This direct contact matters. Heat flows from the component pad into the copper with minimal resistance.
Copper then spreads the heat quickly due to its high thermal conductivity. From there, heat moves into the surrounding air or into a connected heat sink. The path stays short and efficient. Thermal resistance drops. Component temperature remains within safe limits. Under higher loads, performance stays stable because heat is removed more effectively.
Structural Features of Copper Coin PCB
The core idea is vertical heat flow. Heat moves from the component, through the copper coin, and down to the heatsink or bottom copper layer. This path avoids dielectric layers, which tend to resist heat flow. This yields better junction-to-case thermal conductivity over standard PCBs. The effect is clear. Heat leaves the source faster and spreads more efficiently.
Structure varies based on how the copper coin bonds to the PCB. Press-fit types rely on mechanical pressure. Embedded designs form a high-strength structural bond via high-temperature lamination. Inlay structures use precise machining to keep the copper flush with the board. Each method changes thermal resistance, stress distribution, and process difficulty. The final choice depends on both thermal needs and manufacturing limits.
Copper Coin-Embedded PCB Fabrication Method
Inner Layer Process
The process begins by preparing the core substrate through cutting and etching to define the initial circuit patterns. A specialized inner groove is then milled into the board to create the precise cavity where the copper coin will reside. After verification via AOI, the board undergoes a brown oxidation treatment and baking to optimize surface adhesion before moving to the lamination stage.
Outer Layer Process
In this phase, the copper coin is pressed into the board, followed by residual resin trimming and precision surface grinding to achieve a fully flush board surface. The board then moves through a rigorous sequence of drilling, plasma cleaning, and multiple stages of copper deposition and electroplating to build out the vertical connections and external circuitry. Using professional vacuum resin filling and advanced planarization processes ensures a void-free interface between the copper coin and the substrate. This maintains exceptional structural integrity and signal consistency.
The fabrication concludes with the application of a protective solder mask and a Ni-Au surface finish for enhanced durability. Before final packaging, each board must pass a battery of high-level inspections—including impedance, electrical, and AOI testing—to ensure it meets strict thermal and performance specifications. Finally, the boards are routed into required outline dimensions and cleared through FQC and FQA protocols.
Performance & Parameter Comparative Analysis
The right thermal management strategy depends on balancing your power density requirements against budget and manufacturing capabilities. Use the comparison table below to identify which structure fits your specific application:
| Structure Type | Thermal Resistance (K/W) | Power Density | Reliability | Manufacturing Complexity |
| Press-Fit | 0.8−1.2 | Low (<50W/cm2) | Good | Simple (Low Cost) |
| Embedded | 0.4−0.7 | Mid (50−100W/cm2) | Excellent | Moderate |
| Buried Copper Coin | 0.2−0.4 | High (>100W/cm2) | Excellent | High (Challenging) |
Reliability and Cost Factors
Reliability depends largely on how well the copper coin bonds to the PCB. Strong bonding improves heat flow and reduces stress over time. Embedded and inlay structures perform better under thermal cycling. They can handle more than 3000 cycles across wide temperature ranges. This makes them suitable for demanding environments.
Press-fit structures rely on mechanical contact, so performance is more limited. They work well in moderate conditions but may need derating in high-stress applications. Cost also varies with structure. Simpler designs cost less but offer lower endurance. More advanced bonding increases cost, yet it provides better long-term stability.
Copper Coin PCB Advantages
Enhanced Thermal Conductivity
Copper coin PCB designs improve thermal conductivity at the source. The copper insert pulls heat away from the component pad with very low resistance. Heat enters the copper quickly and moves through it with ease. This direct path avoids slower PCB materials, so heat transfer becomes more efficient.
Efficient Heat Dissipation
Efficient heat dissipation comes from how the copper coin spreads heat into the board and beyond. Heat does not stay trapped near the component. It moves outward and reaches the surface faster. From there, it can transfer to air or a heat sink. This keeps operating temperature within safe limits.
Improved Thermal Spreading
Thermal spreading improves because copper distributes heat across a wider area. Instead of a single hot spot, heat becomes more even across the PCB. This reduces stress on components. It also prevents local overheating, which can affect performance over time.
High Power Handling
Copper coin PCB structures support higher power loads without overheating. The direct heat path allows components to run at higher currents while staying within thermal limits. This is important for power electronics, RF systems, and other high-load designs where heat builds up quickly.
Compact Design
A copper coin PCB allows a more compact design without sacrificing thermal performance. Heat is managed inside the board, so large external heat sinks may not be needed. This helps reduce size and profile. It fits well in space-limited systems like portable devices or dense assemblies.
Reliability in Harsh Environments
Reliability improves because temperature stays controlled during operation. Copper coin PCB designs resist thermal stress and cycling better than standard boards. This makes them suitable for harsh environments, where temperature changes and continuous load are common. Over time, the board remains stable and consistent.
Copper Coin Design Considerations
Coin Size and Shape
The coin must match the heat source. Diameter, thickness, and overall shape control how fast heat moves away from the component. A thicker coin lowers thermal resistance, but it also makes processing more complex. A thinner design is easier to build, but it may limit heat handling.
Electrical Safety Distance
Clearance between the copper coin and nearby signal traces is important. Without enough spacing, parasitic coupling or electrical breakdown can occur. High-voltage designs usually require wider spacing and stricter control around the coin edges to keep signals stable.
Surface Protection
Copper reacts with air over time, so surface protection is needed. A proper plating layer prevents oxidation and keeps thermal performance stable during long operation. It also improves soldering quality and long-term reliability of the connection.
No Air Gaps
Good thermal transfer depends on full contact. Any trapped air between the coin and surrounding structure reduces heat flow. Tight bonding and proper lamination help maintain direct heat conduction without interruption.
Flat Surface Control
Flatness affects both assembly and performance. If the surface is uneven, solder joints may become weak or inconsistent. It can also reduce contact quality with heat-generating components. Controlled machining helps maintain stable and even surfaces.
Component Fit
Power devices such as MOSFETs, IGBTs, and silicon carbide components generate concentrated heat. These parts benefit from direct copper contact under the package. Strong thermal coupling helps maintain safe junction temperatures during continuous operation.
Design & Production Constraints of Embedded Copper Coin PCBs
Embedded copper coin PCBs offer strong thermal performance, but they also bring design and production limits. The structure is more complex than standard PCBs. That affects layout freedom, fabrication steps, and overall cost. These factors need to be planned early in the design stage.
More Complex to Manufacture
Embedded copper coins require precise alignment during lamination. The copper must sit exactly in position inside the PCB stack. Any small shift can affect thermal contact or board reliability. This makes fabrication more controlled and time-consuming compared to standard PCB builds.
Less Routing Space
The copper coin takes up internal board space. This reduces available area for signal routing and power planes. In dense designs, routing becomes tighter and more constrained. Careful planning is needed to avoid signal conflicts or layout limitations.
Higher Production Cost
More steps are involved in fabrication, which increases cost. Precision machining, extra inspection, and controlled lamination all add to production effort. Yield rates may also be lower at first, especially for complex stack-ups.
With over 20 years of expertise in thermal management solutions, PCBMay is expertly equipped to handle the complexities of copper coin PCB integration. From precision cavity routing and coin press-fitting to advanced lamination and DFM reviews, we ensure your high-power designs achieve maximum heat dissipation and reliability. If you need a trusted partner for your next thermal project, contact us today for sales@pcbmay.com.
Immersion Gold (ENIG) is typically required. It provides a flat, oxidation-resistant surface that ensures reliable thermal and electrical bonding for high-power components.
A copper coin PCB uses a solid copper insert placed inside the board, usually under high-heat components. This insert moves heat away much faster. A standard copper PCB only uses thin copper layers for electrical paths. It does not include a solid copper block, so its heat dissipation is more limited.
Copper coin PCBs usually use high-purity C1100 electrolytic copper. This material has very good thermal and electrical conductivity, so it moves heat efficiently. The copper coin is embedded directly into the PCB. It is often placed under components that generate high heat.
Custom shapes including square, rectangle, circle and irregular profiles to match diverse component footprints
A solid copper coin is 20–50 times more efficient at heat transfer than a standard via array, making it a necessity for high-frequency RF or power electronics.
It is either press-fitted into a routed cavity after lamination or embedded directly into the stack-up during the lamination process for maximum stability.
Copper has a thermal conductivity of about 401 W/m·K, which is much higher than FR4 materials. This allows heat to move away from components much faster. In practice, component operating temperature can be effectively reduced for long-term stable operation. This often reduces or removes the need for large external heat sinks. The result is a smaller design, with lower space use and reduced overall cost.