Thermal Management in Electronics

Key Takeaways

• How heat is generated in electronic circuits.

• The types of thermal management.

• Thermal management in consumer electronics.

Poor heat dissipation in electronic circuits can cause fires

Have you ever felt your laptop overheat? This happens when the heat generated in the internal electronics circuits is conducted to the outer casing, causing it to heat up. Unfortunately, higher temperatures challenge the performance and reliability of electronic systems. That is why it is crucial to limit the rise in temperature in electronic circuits through proper cooling techniques. The thermal management of electronic circuits plays a significant role in reducing the operating temperature to an allowable value. 

Heat Generation in Electronics Circuits

Electronic circuits are composed of components such as resistors, capacitors, inductors, transformers, semiconductors, integrated circuits (ICs), etc. All these components are responsible for the production of heat in electronic circuits.

Electrical resistance is the basis for heat generation in electronic circuit components. In any material, the electrical resistance opposes the movement of electrons during current flow. It forms friction between the moving electrons and the crystalline structure of the material. In the case of conductors used for making wires, cables, or traces, the electrical resistance is less, but, depending on the current flowing through it, is still capable of generating heat.

In electronic circuits, there is a proliferation of semiconductor materials in the form of power electronic components and power ICs. The electrical resistance of semiconductors is greater than conductors. The semiconductor components produce heat as they operate, which challenges the reliability, performance, and safety of the circuit by increasing junction temperature.

Extreme temperatures can cause thermal runaway or burn off the components, which results in permanent damage to the circuit. Poor heat dissipation in electronic circuits can cause smoke or fire accidents as well. It is important to limit the temperature using proper thermal management techniques. 

Thermal Management in Electronics

In electronics, thermal management methods utilize the principles of thermodynamics and heat transfer to control the temperature and noise in a circuit. Thermal management takes into account the materials (such as coolants or thermal interface materials), tools (such as heat sinks), and technologies (such as finite element analysis or computational fluid dynamics) to remove excess heat from the components to the surroundings. Thermal management focuses on how to efficiently remove heat by means of conduction, convection, or radiation from the electronic component without interrupting the system’s performance. 

Thermal Management Classifications

Thermal management solutions are designed according to the thermal requirements of the electronic circuit. The thermal management in electronic circuits can be categorized into two types:

1. Product-level - This level consists of two sub-classifications: printed wire board-level, which includes the chips, processors, components, etc., and the system-level, which mainly focuses on single and multiple rack-based systems such as servers or data centers.

2. Industry-level - This level addresses the electronic systems used in medical, automotive, defense, aerospace, and consumer electronic systems. The thermal management in each industry places importance on board-level, system-level, and component-level thermal management. However, the importance given to each level differs in different industries. For example, medical electronics gives more priority to system-level thermal management, whereas consumer electronics focus on component-level thermal management. 

Thermal Management in Consumer Electronics

Miniaturization in consumer electronics, such as smartphones, smartwatches, tablets, computers, home appliances, etc., aggravates thermal losses, and these gadgets require careful thermal management.

Materials with high thermal conductivity properties are employed in consumer electronics so that the heat produced is transferred to the cooling systems attached to the circuit. Cooling systems are typically heat sinks, heat spreaders, or heat pipes.

Apart from conventional cooling systems, advanced hybrid systems such as cryogenics cooling, microchannel cooling, refrigerant cooling, thermal vapor chambers, microwetting, cold plates, and phase change materials can be used in consumer electronic systems to increase the heat dissipation rate. A new class of coolants called nanofluids and ionanofluids are revolutionizing the thermal management of consumer electronic systems. Innovative technologies such as computational fluid dynamics (CFD) and finite element analysis (FEA) are widely in use for predicting hotspots and the distribution of air and temperature in the body of consumer electronic systems.

Cadence software can help you design thermal management solutions for your electronic circuits.  Subscribe to our newsletter for the latest updates. If you’re looking to learn more about how Cadence has the solution for you, talk to our team of experts.