Every device has a minimum and maximum operating temperature, which can impact performance, safety, longevity and cost. Thermal management solutions help to prevent overheating by dissipating excess heat. Thermal management materials perform multiple functions within components, including cooling, protecting against thermal cycling and filling gaps.
Conduction
With electrification trends driving more powerful and compact electrical devices, manufacturers face new thermal challenges to maintain optimal temperatures. Without effective thermal management, these devices can overheat, resulting in diminished performance and shortened lifespan.
Effective thermal solutions, like cooling systems and heat sinks, mitigate this excess heat to prevent overheating and ensure electronic devices remain operational longer. Conduction is a form of energy transfer that occurs when atoms within materials interact to generate heat.
This heat is transferred when fast or vigorously moving particles bump into less energetic particles, causing them to move faster or vibrate more vigorously. This interaction, or vibration, produces additional heat that is then dissipated by the slower particles.
To transfer heat effectively, a material must have high thermal conductivity. Copper has relatively high conductivity but comes with a weight penalty that may be undesirable for many applications. Other metals, like silver and pyrolytic graphite, have even higher conductivities but are often too expensive for industrial applications.
A new solution to these challenges is emerging from nanotechnology, a field that makes various advanced thermal management products possible. These products can reduce device and component costs while meeting thermal management requirements across multiple industries.
In addition to delivering lower product costs, these solutions offer benefits such as stress relief, electromagnetic shielding, chemical resistance and electrical insulation.
Radiation
The increasing miniaturization of electronic devices such as smartphones and tablets drives the need for thermal management solutions. These solutions are required to maintain optimized temperatures in these products and prevent the system from overheating, which may damage or disrupt the operation.
As these products become more sophisticated, they generate more heat from increased power requirements, operating speeds and confined spaces. This increased heat generation and operating temperature thresholds may exceed the capabilities of current thermal solutions.
Innovative solutions are needed to manage the excess heat that can cause these systems to overheat and deteriorate. All circuits and devices generate some extra warmth, requiring a cooling mechanism to reduce the temperature to an acceptable level for normal operations.
These technologies include conduction, convection (natural and forced), and radiation. Conductive materials like copper are commonly used to spread heat across the surface of a device, but these materials have a limited ability to carry thermal energy over long distances.
A thermal management solution with a high-heat transfer coefficient may be required for more complex designs and higher operating temperature applications. Silver, diamond and pyrolytic graphite have a high-heat transfer coefficient, but they come with a weight penalty and are often expensive for most commercial products.
Other thermal management materials such as kapton, dispensable phase change and grease provide various temperature regulation options for electronic devices. These multifunctional materials can offer stress relief from thermal cycling, provide electrical insulation, fill gaps and submit long-term stability in various environments and applications.
Convection
As circuits and devices become more complex and deliver higher power levels, thermal management becomes necessary. Without it, heat can cause devices to overheat, negatively affecting their performance and lifespan.
High temperatures threaten the integrity of components, especially in areas with restrictions on heat spreading and convection limitations. These challenges require innovative solutions that allow increased speeds and power requirements to be met within temperature limits.
Cooling technologies like heat sinks, Peltier modules and fans allow energy transfer into a lower-energy state to prevent overheating. They can also dissipate excess heat to ensure a device’s highest possible performance and longevity.
As a key component of any cooling system, the TIMs used are designed to enhance the effectiveness of this transfer process. They are formulated to reduce the amount of surface area required by the device for the heat to dissipate, which decreases the overall temperature of the device.
TIMs are also used in applications like LED lights, electric motors and solar panels to improve the efficiency and lifespan of these devices by increasing their ability to dissipate excess heat. Other industries that utilize these technologies include medical and aerospace, where the machines must be safe to touch for human use and operate in harsh environments.
Liquid Cooling
Cooling is an essential aspect of the design process for electronic devices, particularly those with high levels of heat-emitting transistors. High temperatures can cause short-circuiting, which damages various components inside a machine and reduces its useful lifetime. Cooling helps prevent this by ensuring that the device’s temperature stays below the threshold where it will begin to fail due to thermal stress.
Liquid cooling is a method of cooling that uses liquids to absorb and transport heat from the device. It is a powerful and effective technology that can dissipate heat faster than air or conduction. It explains that liquid cooling systems typically consist of a cold plate, a pump, and a heat exchanger. The cold plate interfaces with the heat source; the pump transfers the cooling fluid, and the heat exchanger rejects the excess heat.
The type of cooling system used will depend on the intended use for a given product. For example, a continuous glucose monitoring patch worn on a patient might not need to withstand the heat of an industrial processor.
