{"id":824,"date":"2026-08-21T10:11:20","date_gmt":"2026-08-21T01:11:20","guid":{"rendered":"https:\/\/www.seiken.co.jp\/english\/?post_type=case_study&p=824"},"modified":"2026-08-21T14:40:13","modified_gmt":"2026-08-21T05:40:13","slug":"solution-16","status":"publish","type":"case_study","link":"https:\/\/www.seiken.co.jp\/english\/case_study\/solution-16\/","title":{"rendered":"Copper Coin PCB: Solving Thermal Challenges in High-Power Electronic Designs"},"content":{"rendered":"\n

High Thermal Conductivity PCB Solutions from Prototype to Low-Volume Production<\/strong><\/h4>\n\n\n
\n
\"Copper<\/figure>\n<\/div>\n\n\n

A Copper Coin PCB(also known as a Copper Inlay PCB) is an advanced thermal management solution that efficiently transfers heat away from high-power components through the shortest possible thermal path while maintaining excellent design flexibility.<\/p>\n\n\n\n

As power devices and high-density electronic assemblies continue to generate more heat, effective thermal management has become essential for ensuring product performance, reliability, and long-term durability.<\/p>\n\n\n\n

\n
\n

Customer Challenges \/ Request<\/h2>\n\n\n\n

The customer was experiencing excessive temperature rise on the PCB due to the mounting of high-power components. Their requirements include:<\/p>\n\n\n

\n
\"Copper<\/figure>\n<\/div>\n\n\n
    \n
  • Reduce the temperature rise around heat-generating components. <\/li>\n\n\n\n
  • Improve heat dissipation beyond what could be achieved with thermal vias alone. <\/li>\n\n\n\n
  • Avoid increasing the overall product size by adding heat sinks or other thermal management components. <\/li>\n\n\n\n
  • Support low-volume prototyping, which can be difficult for conventional mass-production PCB manufacturers.<\/li>\n<\/ul>\n\n\n\n

    During the prototyping stage in particular, many PCB manufacturers require dedicated tooling and minimum order quantities because their manufacturing processes are optimized for mass production. As a result, producing a single prototype board or accommodating design changes can be difficult.<\/p>\n<\/div>\n<\/div>\n\n\n\n

    Our Solution<\/h2>\n\n\n\n

    After reviewing the requirements, Seiken proposed the following PCB structure:<\/p>\n\n\n\n

      \n
    • Place a copper inlay directly beneath the heat-generating component<\/strong>.<\/li>\n\n\n\n
    • Add a dedicated thermal dissipation structure while maintaining the existing circuit design.<\/li>\n\n\n\n
    • Maintain the existing multilayer PCB structure<\/strong>.<\/li>\n\n\n\n
    • Optimize the design without sacrificing available component mounting area.<\/li>\n\n\n\n
    • Provide prototype production starting from a single board<\/strong>.<\/li>\n<\/ul>\n\n\n\n

      Results & Benefits<\/h2>\n\n\n\n
        \n
      1. Improved heat dissipation and reduced total cost: <\/strong>By incorporating a copper coin structure into the PCB, the following benefits can be achieved. <\/li>\n\n\n\n
      2. Improved heat dissipation:<\/strong> The copper inlay efficiently transfers heat away from heat-generating components, helping to suppress increases in component temperature. <\/li>\n\n\n\n
      3. Improved reliability:<\/strong> Copper has a lower coefficient of thermal expansion than aluminum. This can reduce stress on solder joints and contribute to improved long-term reliability. <\/li>\n\n\n\n
      4. Reduced assembly work:<\/strong> By integrating the heat dissipation structure into the PCB, separately installed heat dissipation components and mounting screws can potentially be eliminated, reducing assembly time and labor. <\/li>\n\n\n\n
      5. Reduced system cost: <\/strong>Reducing the number of components and assembly processes can help optimize the overall system cost. <\/li>\n\n\n\n
      6. Flexible support for prototypes and small-lot production: <\/strong>Because prototype production is available from a single board, customers can evaluate designs with lower risk during the early stages of development. <\/li>\n<\/ol>\n\n\n\n

        Unlike conventional PCB manufacturers that primarily focus on mass production, Seiken can support small-lot prototypes, including production from just one board<\/strong>. We also provide technical consultation from the design stage. No initial setup fees or tooling costs are required<\/strong>, allowing us to respond flexibly to early-stage evaluations and design or specification changes.<\/p>\n\n\n\n

        Copper Inlay vs. Thermal Via: Performance Comparison<\/h4>\n\n\n\n
        PCB Thickness<\/th>Copper Inlay Diameter<\/th>Thermal Resistance of Copper Inlay<\/th>Thermal Vias Required for Equivalent Performance<\/th>Approx. Minimum Area Required for Via Array<\/th><\/tr>
        1.0 mm (Thin, high-thermal-performance)<\/td>\u03c62.0 mm<\/td>0.82\u00b0C\/W approx.<\/td>145 vias<\/td>4.8 \u00d7 4.8 mm\u00b2\u3000approx.<\/td><\/tr>
        1.0 mm (Thin, high-thermal-performance)<\/td>\u03c63.0 mm<\/td>0.36\u00b0C\/W approx.<\/td>327 vias<\/td>7.2 \u00d7 7.2 mm\u00b2\u3000approx.<\/td><\/tr>
        1.6 mm (Standard rigid PCB)<\/td>\u03c62.0 mm<\/td>1.30\u00b0C\/W approx.<\/td>145 vias<\/td>4.8 \u00d7 4.8 mm\u00b2\u3000approx.<\/td><\/tr>
        1.6 mm (Standard rigid PCB)<\/td>\u03c63.0 mm<\/td>0.58\u00b0C\/W approx.<\/td>327 vias<\/td>2.7 \u00d7 7.2 mm\u00b2\u3000approx.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
        \n
        \n

        Thermal via conditions:<\/strong> Via diameter: \u03c60.3 mm; hole-wall plating thickness: 25 \u03bcm (typical specifications).<\/p>\n\n\n\n

        Note:<\/strong> The thermal resistance values are theoretical values calculated based on the bulk thermal conductivity of pure copper (390 W\/m\u00b7K). Contact thermal resistance is not included.<\/p>\n\n\n

        \n
        \"Copper<\/figure>\n<\/div>\n\n\n

        Application<\/strong><\/h2>\n\n\n\n

        Copper inlay PCBs are particularly suitable for products that generate significant heat or require high reliability, including:<\/p>\n\n\n

        \n
        \"Copper<\/figure>\n<\/div>\n\n\n