Whether you are working with power electronics on a PCB board, embedded systems, industrial equipment, or designing a new motherboard, dealing with rising temperatures in your system is essential. Continued high temperature operation can shorten the life of the circuit board and may even cause failure at critical points in the system. Therefore, considering heat dissipation early in the design process can help extend the life of your boards and components.
Thermal design starts with estimating the operating temperature of the board. Before starting a new design, it is important to consider the temperature at which the board will be operating, the environment in which the board will operate, and the power dissipation of the components. These factors all work together to determine the operating temperature of the board and its components. Additionally, this information will be useful when developing custom cooling strategies.
It is important to note that placing the board in an environment with a warmer ambient temperature will cause it to retain more heat, resulting in the board running at a higher temperature. Therefore, it is crucial to take into account all environmental and operational factors when assessing operating temperatures and implementing cooling solutions.
As a PCB expert, I will make the following changes to the article:
1. Components that dissipate more power will require more efficient cooling methods to maintain temperatures at designated levels. Important industry standards may dictate the temperature of components and substrates during operation. Before designing a thermal management strategy, it is important to check the allowable operating temperature of the component in the data sheet and the specified temperature in important industry standards.
2. Active and passive cooling must be combined with proper board layout to prevent damage to the board. It is important for designers to consider whether active or passive cooling is right for their board.
3. Typically, passive cooling works when the ambient temperature is significantly lower than the operating temperature, creating a large thermal gradient between the system and the environment. Active cooling, on the other hand, can provide better cooling even if the ambient temperature is higher.
4. Attempts should be made to reduce passive cooling of active components to levels that allow heat to spread to the ground plane. Many active components include thermal pads on the bottom of the package that allow heat to dissipate through stitched vias to a nearby ground plane.
5. There are some PCB board calculators that can be used to estimate the size of the copper pads needed under the components. If a single pad doesn’t reduce the temperature to the desired level, a heat sink can be added on top of the unit to dissipate more heat. Thermal pads or thermal paste can also be used to increase the heat flux into the heat sink.
6. Evaporative cooling is another option, but it is not suitable for many systems as the components are bulky and can lead to fluid leaks if the system leaks or ruptures.
7. If passive cooling does not solve the problem of reducing the temperature of active components such as FPGAs or CPUs, active cooling with fans may be necessary. The fans don’t run at full speed all the time, and sometimes they might not even turn on. Hotter components and components that generate more heat require fans to run at faster speeds.
8. Active cooling systems such as coolant or refrigerant can also be used to provide substantial cooling, but this is uncommon because it requires a pump or compressor to move the coolant or refrigerant through the system.
9. Using a ground plane under signal traces improves signal integrity and noise rejection, and it also acts as a heat sink. Components with thermal pads can extend stitched vias down to the ground plane to make it easier for the ground plane to dissipate heat from the surface layer.
10. Traces that carry high currents, especially in DC circuits, will need to have more copper weight in order to dissipate the right amount of heat on the board. This may require wider traces than those typically used in high-speed or high-frequency devices.
11. Thermal cycling in circuit boards can cause stress to build up in vias and traces, leading to tube breakage in high aspect ratio vias. Prolonged cycling can also cause trace delamination on the surface layer, which can damage the PCB board.
Thermal design starts with estimating the operating temperature of the board. Before starting a new design, it is important to consider the temperature at which the board will be operating, the environment in which the board will operate, and the power dissipation of the components. These factors all work together to determine the operating temperature of the board and its components. Additionally, this information will be useful when developing custom cooling strategies.
It is important to note that placing the board in an environment with a warmer ambient temperature will cause it to retain more heat, resulting in the board running at a higher temperature. Therefore, it is crucial to take into account all environmental and operational factors when assessing operating temperatures and implementing cooling solutions.
As a PCB expert, I will make the following changes to the article:
1. Components that dissipate more power will require more efficient cooling methods to maintain temperatures at designated levels. Important industry standards may dictate the temperature of components and substrates during operation. Before designing a thermal management strategy, it is important to check the allowable operating temperature of the component in the data sheet and the specified temperature in important industry standards.
2. Active and passive cooling must be combined with proper board layout to prevent damage to the board. It is important for designers to consider whether active or passive cooling is right for their board.
3. Typically, passive cooling works when the ambient temperature is significantly lower than the operating temperature, creating a large thermal gradient between the system and the environment. Active cooling, on the other hand, can provide better cooling even if the ambient temperature is higher.
4. Attempts should be made to reduce passive cooling of active components to levels that allow heat to spread to the ground plane. Many active components include thermal pads on the bottom of the package that allow heat to dissipate through stitched vias to a nearby ground plane.
5. There are some PCB board calculators that can be used to estimate the size of the copper pads needed under the components. If a single pad doesn’t reduce the temperature to the desired level, a heat sink can be added on top of the unit to dissipate more heat. Thermal pads or thermal paste can also be used to increase the heat flux into the heat sink.
6. Evaporative cooling is another option, but it is not suitable for many systems as the components are bulky and can lead to fluid leaks if the system leaks or ruptures.
7. If passive cooling does not solve the problem of reducing the temperature of active components such as FPGAs or CPUs, active cooling with fans may be necessary. The fans don’t run at full speed all the time, and sometimes they might not even turn on. Hotter components and components that generate more heat require fans to run at faster speeds.
8. Active cooling systems such as coolant or refrigerant can also be used to provide substantial cooling, but this is uncommon because it requires a pump or compressor to move the coolant or refrigerant through the system.
9. Using a ground plane under signal traces improves signal integrity and noise rejection, and it also acts as a heat sink. Components with thermal pads can extend stitched vias down to the ground plane to make it easier for the ground plane to dissipate heat from the surface layer.
10. Traces that carry high currents, especially in DC circuits, will need to have more copper weight in order to dissipate the right amount of heat on the board. This may require wider traces than those typically used in high-speed or high-frequency devices.
11. Thermal cycling in circuit boards can cause stress to build up in vias and traces, leading to tube breakage in high aspect ratio vias. Prolonged cycling can also cause trace delamination on the surface layer, which can damage the PCB board.
