With the rapid development of technology, thermal management issues at the bare PCB and assembly levels have become increasingly important. Whether in high-brightness LED applications, high-power transmitters, or high-voltage power supplies, the demands for heat dissipation and thermal conduction are constantly rising.

At the PCB and component levels, the core goal of thermal management is to effectively transfer heat from heat-generating components to external heat sinks for dissipation. More efficient thermal conduction can often extend the Mean Time Between Failures (MTBF) and, in some cases, is even critical for the product to meet design requirements.

Rapid Development of Embedded Copper PCB Technology

Embedded copper PCBs, also known as copper coin PCBs, significantly enhance heat transfer speed when high thermal conductivity materials are used. Copper, with a thermal conductivity as high as 400 W/mK, is comparable to materials like diamond—although diamond’s thermal conductivity can reach five times that of copper, it is obviously impractical for use in PCBs. Thus, copper becomes an ideal choice for managing heat, offering both excellent electrical and thermal conductivity.

Embedded copper PCBs incorporate or place a solid copper piece within the PCB, typically under components requiring heat dissipation. Compared to using a via array, copper coin heat dissipation is approximately twice as effective. Additionally, copper blocks can directly connect the pads of heat-generating components to heat sinks without needing thermal interface materials. Copper’s thermal conductivity generally exceeds that of any conductive dielectric prepreg by 30 to 200 times.

When is it Most Suitable to Use Embedded Copper PCB Technology?

Embedded copper technology is particularly well-suited for PCB designs where a few components generate the majority of the heat. Regardless of the number of layers or materials in the PCB, embedded copper technology can provide an optimal thermal conduction solution in localized areas. The principle involves press-fitting a copper coin into a pre-cut area of the PCB, located directly beneath identified hot spots, allowing heat to be conducted directly through the PCB layers to the heat sink. This approach avoids common thermal bottleneck issues found in traditional PCB materials.

Copper coins can be embedded in the PCB in various forms and configurations. The configuration chosen by designers is typically a compromise among routing, power layer requirements, and the distance between the copper coin and the components needing cooling.

Types of Embedded Copper PCBs

Embedded copper PCBs generally come in two types: buried copper blocks and embedded copper blocks. A buried copper block refers to a copper piece whose thickness is less than the total thickness of the board, with one side flush with the bottom layer and the other side flush with an inner layer, as shown in Figure 1 (Cu Coin half buried). An embedded copper block, on the other hand, has a thickness close to or equal to the total thickness of the board, with the copper block passing through the top layer, as shown in Figure 2 (Cu Coin through).

PCBs with buried or embedded copper blocks feature high thermal conductivity and excellent heat dissipation while saving board space, effectively addressing the heat dissipation issues of high-power electronic components.