Introduction to Thermal Resistance of Modern Electronic Products

As devices become more powerful and compact in size, engineers from different industries have been working tirelessly on thermal management of electronic products. Although there are many innovative solutions that can take away thermal energy through high-temperature heat conducting devices such as fans, liquid coolers, and heat conducting tubes, there have been many advances in the device itself to fundamentally optimize thermal performance. To help you better understand how to optimize your device and thermal management system, this article outlines the main components of thermal performance in electronic products, and points out some key parameters that allow you to operate on the device to optimize the flexibility and performance of the cooling system.https://store.stoneitech.com/
Operating ambient temperature
When designing final products such as IoT devices, medical tools, or industrial sensor devices, almost every device takes the maximum ambient operating temperature as a parameter. The maximum ambient temperature is set by the manufacturer of the device to ensure that the performance of the device meets acceptable standards and that physical properties are not compromised. For example, some switching transistors can withstand very high power loads, but if exposed to excessive ambient temperatures, their internal semiconductor junctions can melt. In addition, temperature directly affects the electrical conductivity of the material, and exceeding the maximum operating temperature may change the performance of the device.
Remove heat from source
Devices with fixed internal power consumption and ambient temperature thresholds, like most power conversion devices and ICs, the surface temperature of the enclosure depends on the internal thermal resistance and efficiency of heat transfer. Internal thermal resistance describes the efficiency of heat transfer from a heat source to a device surface. However, when most people think of thermal management, they think of the efficiency of heat transfer from devices to the environment, which is known as convective, conductive, or radiant heat transfer. These methods are typically passive heat exchangers, fans, liquid cooling systems, heat pipes, and radiators.
The best way to maintain a good housing temperature is to directly change the internal thermal resistance of the device and the efficiency of radiating heat to the surrounding environment. A perfectly thermally managed device has zero thermal resistance and infinite heat dissipation. However, since devices are made of real-world materials, each material has its own unique thermal resistance characteristics, and no system can perfectly transfer heat, system designers must seek to optimize the thermal performance of each key device from the early stages of design.
Fixed variable
As many designers know, the various parameters of an application are usually fixed, so it is necessary to develop a design to meet these requirements. In some cases, the efficiency of the device, the ambient temperature, and the heat transfer mechanism of the system depend on the final application. In many cases, the only way for devices to achieve acceptable operating conditions and low enclosure temperatures is to choose to improve their internal thermal design and select devices with low internal thermal resistance.
Optimized internal thermal resistance
There are two key parameters to check, one is the overall thermal resistance of the device and the other is the thermal resistance between junction temperature and ambient temperature Ψ Jt and θ ja。 Ψ Jt and θ Ja is a unique thermal resistance parameter for each device, and varies depending on the packaging. Ψ Jt is a thermal characteristic parameter used to measure multiple heat flow paths between the heat source and the packaging surface θ Ja represents the linear thermal resistance between the heat source and ambient temperature. Ψ Jt is power dependent, at higher power consumption and enclosure temperature Ψ The increase of jt will ultimately reduce the performance of the device. Even if optimized Ψ Jt, high θ The resistance value of ja can also cause excessive housing temperature and limited ambient operating temperature.
There are many ways to improve that can reduce Ψ Jt and θ Ja, such as material optimization, manufacturing techniques, and different methods of heat transfer to the environment. One of the latest advances in reducing thermal resistance is 3D Power Packaging ®。 Using 3D Power Packaging ® (3DPP) technology, such as FCOL, embedded IC, heat sink, etc., has successfully significantly improved RECOM Ψ Jt and θ Ja value. By reducing these values for 3DPP products, higher power performance can be achieved without limiting the ambient temperature of the device. High power density solutions such as products such as 3DPP are designed for high-performance and efficient equipment without the need for active cooling or large passive heat sinks.
For more information on the importance of RECOM’s cutting-edge 3DPP technology and low thermal resistance in efficient power supply design, please visit our 3DPP application page or contact us to order a RECOM 3DPP evaluation board.