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What is the Role of Thermal Vias in PCB Assembly?

Role of Thermal Vias in PCB Assembly

The main role of thermal vias in pcba is to allow heat from components to be transferred more easily from the PCB surface layers to its inner plane layers. They are plated through-holes (PTH) in the PCB that, when filled with thermal epoxies or solder, create solid metal poles spanning the layers of the board. Proper use of thermal vias is a critical PCB thermal management solution, especially for high power and tightly packed assemblies.

As a rule of thumb, via plating thickness should be between 20 and 30 microns for best performance. Thicker plating increases resistance, and the added cost does not offer a significant advantage. However, a lower plating thickness may result in a lower thermal resistance value, but this is usually not a problem for most applications.

A thermal via’s effectiveness in cooling depends primarily on its position in the layer stack and the substrate material. Copper, with its high thermal conductivity, is ideal for transporting heat between vias and the inner layer of your board’s stackup. This helps mitigate temperature rise and eliminates hot spots around the pads of your active components.

Thermal vias also reduce thermal gradient, which makes it easier for your circuit board to cool itself. When placed close to power ICs and processors, thermal vias reduce the distance over which heat is transported from those components to the rest of the board, thus decreasing the total amount of energy required.

What is the Role of Thermal Vias in PCB Assembly?

In addition to reducing the need for other cooling methods, thermal vias can also improve your PCB’s reliability by improving its durability under operating conditions. This is because the lower thermal gradient can help your component stay below its operating temperature for longer, and it will not reach a higher temperature as quickly.

Another benefit of using thermal vias is that they can help with EMI reduction by allowing your short power traces to connect to the internal ground plane. This will decrease the chance of electrical shorting, which can cause failures and other problems. To prevent this, it is a good idea to place small keepouts around the sensitive areas of your board.

To get the most benefit from thermal vias, your design software should include features to assist with their placement and arrangement. These tools will define standard geometry for your thermal vias and their span throughout your layer stack, enabling you to implement a comprehensive thermal management strategy in your board design. The best tool will also provide a range of other routing and layout features, giving you a complete suite of circuit board design tools in one platform.

Sierra Circuits’ engineers and technicians have the experience to bring your electronic designs to life, so contact us today to discuss your project! We are committed to providing fast and flexible service, and we can accommodate any assembly requirements that you might have. In addition, we can offer you DFMA recommendations to ensure that your PCB design is in line with manufacturing guidelines and will be ready for mass production.


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