What is Thermal Management- Passive and Active Thermal Management

What is thermal management as it applies to electronic devices? All electronic systems emit thermal energy, which is unsuitable for optimal performance. 

Therefore, manufacturers go to great lengths by creating effective heat exchange systems that keep the device parts cool during operation. 

But is this justified, or rather what harm can excess heat cause to the functionality of the electronic systems?

Every innovation in electrical engineering is a result of extensive studies. So what is the science behind thermal management technologies? Read on to find out. 

What is Thermal Management?

It is the application of strategies that maintain the thermal levels of any system within its recommended operating range. 

The specific role of thermal management in electronic systems is ensuring the devices can emit the excess heat generated internally that could harm performance. 

The theme of thermal management is widespread with various applications in different fields like the aerospace industry, battery thermal management systems, and data centers.

Hence, the nature of thermal control systems ranges from simple to sophisticated.

How does Thermal Management Work?

Thermal monitoring concept. 

Thermal monitoring concept. 

Thermal management is a simple principle that operates under the three principles of heat energy transfer. Here’s an exclusive illustration of how each of them works. 


Applying a heat-conducting paste to the heat distributor. 

Applying a heat-conducting paste to the heat distributor. 

The heat dissipation method relies on contact between two heat conductors. It depends on a heat energy gradient whereby the excess energy flows from the object with the higher temperature to the lower one. 

One of the primary condition upsides is that it occurs with flat surfaces that lack a large surface area. A small section is enough to allow heat transfer. The leading examples of conductive materials operating under conduction include the following: 

  • Heat spreaders
  • Heat sinks


An oven applies the conventional heat transfer mode. 

An oven applies the conventional heat transfer mode. 

The technique relies on the varying flow of air properties to move heat from one medium to another. 

In air systems (liquid cooling) relying on convention, cold air passes through a hot media causing it to heat up. It will lead the hot air to rise as another stream of cold air passes through the media leading to an overall cooling effect. 

While air cooling is not as excellent as other transfer modes, such as conduction, it still helps to expel a significant amount of heat. The most common convention transfer components you’ve probably interacted with include blowers and fans. 


Illustrating radiation in therapy treatments. 

Illustrating radiation in therapy treatments. 

Heat doesn’t necessarily require passing through a physical medium. This is the case with radiation, whereby heat energy travels via electromagnetic waves resulting from the excitation of hot air particles. 

Hot particles have a kinetic energy that compels them to travel from their source to the point of low concentration. 

What is the Difference between Active and Passive Thermal Management?

Heatsink Thermoelectric Cooling Cooler Peltier Plate. 

Heatsink Thermoelectric Cooling Cooler Peltier Plate. 

We have two encapsulating modes of thermal management: 

  • Active Systems
  • Passive Systems

Active Systems

Active solutions use energy sources such as electricity or battery power to function. Their examples include the following: 

Forced convection

A typical forced convention device is a fan blowing cold air onto a heat-generating component in electronic systems or general cooling applications. 

The fundamental role of such a blower is to improve the cooling rate by delivering a rapid flow of cool air which hinders heat accumulation. 

Thermoelectric coolers

Heat dissipation in circuit boards with sensitive components such as semiconductors depends on these solid-state heat pumps. Their role is to optimize the effectiveness of heat sinks in drawing heat off the source. 

Therefore, they sit between these two parts and create a temperature gradient that prompts heat flow. 

Passive Systems

A heat sink on the motherboard. 

A heat sink on the motherboard. 

Unlike active systems, passive technologies don’t require a connection to a power source. It is because they primarily function via the three modes of heat transfer we discussed earlier. 

Examples of passive cooling systems include the following: 

Heat Spreaders

As per their name, they are metal plates that distribute heat over an extensive area. It enhances heat loss and prevents its concentration on delicate parts of electrical components. 

Heat Sinks

Most complex 3-D circuits feature heat sinks as the primary heat transfer medium. Like heat spreaders, they are highly conductive metal materials that act as a medium between the heat source and the conventional transfer system. 

They will conduct the heat from the interior of an electronic device and direct it to a conventional system that transfers it outside with blowers or fans. 

Applications for Advanced Thermal Management

Illustrating PCB thermal management concept. 

Illustrating PCB thermal management concept. 

How does thermal management impact components’ performance, reliability, and durability across various fields that apply them? Let us lay down some of the top areas where thermal efficiency matters. 

Medical Equipment

Modern medical electronic equipment. 

Modern medical electronic equipment. 

The health sector is one of the primary dependents of electronic systems in almost all areas, from disease diagnosis to treatment solutions.

Hence, the efficiency of these components is imperative, especially given their delicate applications in life-and-death scenarios. 

Thermal management products find great use in this sector as there could be high equipment breakdown rates in their absence, which puts patients’ lives at risk.

Moreover, medical equipment must be highly responsive to generate the right results. 

Hence, they must have the ideal thermal conditions of operation, which explains the considerable investment of manufacturers in enhancing heat dissipation in medical components. 

Embedded Computing Applications

Embedded computer boards. 

Embedded computer boards. 

The health of embedded systems is critical to the overall efficiency of the main device operation. However, this is only possible if it has a working thermal management system to facilitate its running. 

Engineers with embedded systems employ critical thermal interface materials to deal with the heat issue, which, if ignored, can become a significant issue. 

Industrial Applications

Industries require top-performing equipment for high throughput rates and production efficiency. 

Therefore, they must create efficient thermal management practices to boost the performance of electronic parts.

The components that require close heat management controls include diodes, thyristors, and motor drives in their electronic equipment. 

Transportation Applications

Charging an EV car. 

Charging an EV car. 

All transport media feature electronic parts whose performances can improve with efficient heat management. For instance, one of the latest innovations in the transport field is electric vehicles that run on batteries. 

Battery life significantly dips if it operates under extreme heat conditions, and since overheating is inevitable, the power battery requires a dissipation system. 

Other parts in the transport field that also need thermal management attention include MOSFETs, suspension cooling systems, and power electronics. 

Defense and Aerospace Applications

The conventional temperature control measures may not work for military and aerospace equipment as they are highly sophisticated and specialized. 

Their performance must be top-notch; otherwise, they will compromise the safety of the personnel in the respective fields. 

Hence, the solution is to create highly innovative, foolproof temperature control mechanisms even under extreme conditions. 

Top Thermal Management Challenges

Heat Spreading

It is a major challenge with high-heat flux devices whereby the erected materials cannot distribute the heat from the source to the heat loss media. 

To solve it, Electronic equipment manufacturers need to use highly conductive materials that are lightweight such as vapor chambers. 

Convention Limitation

Most heat emission modes in electronic components primarily rely on the convention as the primary transfer method of removing the heat from the electrical device. 

Nonetheless, as mentioned earlier, the technique is less effective than conduction.

It can also actually fail if there’s excessive heat dissipation demand. The solution to the challenge is ensuring the heat sink is large enough to increase the surface area for heat loss. 

Also, improving airflow into the system can enhance the rate of heat motion from the device. The other measure includes using a fin of thicker width. 

High Ambient Temperatures

Passive heat transfer modes depend on low ambient temperatures to expel heat from systems. 

Hence, when the ambient temperatures are high, delta T (Temperature Gradient) is so low that heat loss is significantly curtailed. 

The solution to this challenge is to use either of the following: 

  • Vapor Compression
  • Peltier Modules. 


Heat in electronics may seem harmless, but it poses a significant challenge to the performance of electronic components. 

It is the basis of thermal management; when effectively conducted, there are numerous benefits in device performance. 

Complex systems may require more than one heat management mode, but a heat loss mode as a fan will do the job in simple devices such as consumer electronics. 

Thank you for reading to the end, and take heed of what we have covered in this article regarding managing device temperatures.