Thermal effects in packaging high power light emitting diode arrays

Review of applications and developments of ultra-thin micro heat pipes for electronic cooling

As an increasing attention towards sustainable development of energy and environment, the power electronics (PEs) are gaining more and more attraction on various energy systems. The insulated gate bipolar transistor (IGBT), as one of the PEs with numerous advantages and potentials for development of higher voltage and current ratings, has been used in a board range of applications. However, the continuing miniaturization and rapid increasing power ratings of IGBTs have remarkable high heat flux, which requires complex thermal management. In this paper, studies of the thermal management on IGBTs are generally reviewed including analyzing, comparing, and classifying the results originating from these researches. The thermal models to accurately calculate the dynamic heat dissipation are divided into analytical models, numerical models, and thermal network models, respectively. The thermal resistances of current IGBT modules are also studied. According to the current products on a number of IGBTs, we observe that the junction-to-case thermal resistance generally decreases inversely in terms of the total thermal power. In addition, the cooling solutions of IGBTs are reviewed and the performance of the various solutions are studied and compared. At last, we have proposed a quick and efficient evaluation judgment for the thermal management of the IGBTs depended on the requirements on the junction-to-case thermal resistance and equivalent heat transfer coefficient of the test samples.

Thermal Management on IGBT Power Electronic Devices and Modules

Heat transfer—A review of 2005 literature

Heat transfer performance of screen mesh wick heat pipes using silver–water nanofluid

Thermal dissipation in power electronics systems is becoming an extremely important issue with the continuous growth of power density in their components. The primary cause of failure in this equipment is excessive temperatures in the critical components, such as semiconductors and transformers. This problem is particularly important in power electronic systems for space applications. These systems are usually housed in completely sealed enclosures for safety reasons. The effective management of heat removal from a sealed enclosure poses a major thermal-design challenge since the cooling of these systems primarily rely on natural convection. In this context, the presented paper treats the heat pipes as effective heat transfer devices that can be used to raise the thermal conductive path in order to spread a concentrated heat source over a larger surface area. As a result, the high heat flux at the heat source can be reduced to a smaller and manageable level that can be dissipated through conventional cooling methods. The objective of our work is to describe the feasibility of a cooling system with miniature heat pipes embedded in a direct bonded copper (DBC) structure. The advantage of this type of heat pipe is the possibility for implementation of the component layout on the heat pipe itself, which eliminates the existence of a thermal interface between the device and the cooling system

Heat Pipe Integrated in Direct Bonded Copper (DBC) Technology for Cooling of Power Electronics Packaging

As the power densities of power components continue to grow, thermal issues are becoming extremely important and vital for the product quality. The primary causes of failures in electronic equipment are the excessive temperatures of the critical components, such as semiconductors and transformers. Power systems for space application are usually housed in completely sealed enclosures due to safety reasons. Since the cooling of these systems primarily relies on natural convection, the effective management of the heat removal from a sealed enclosure poses a major thermal-design challenge. In this context heat pipes are very effective heat transfer devices and can be used to raise the thermal conductive path in order to spread a concentrated heat source over a much larger surface area. As a result, the high heat flux at the heat source can be reduced to a much smaller and manageable level that can be dissipated through conventional cooling methods. The objective of this work, presented in this paper is to describe the feasibility of a cooling system with miniature heat pipes embedded in a direct bonded copper structure (DBC). The advantage of this kind of heat pipe is the integration of the electronic component layout directly on the heat pipe itself, which eliminates the existence of a thermal interface between the device and the cooling system

Heat Pipe Integrated in Direct Bonded Copper (DBC) Technology for the Cooling of Power Electronics Packaging

A novel heat pipe design was developed consisting or a ceramic substrate sandwich with integrated flat heat pipe. On both sides of the heat pipe active electronic components, such as IGBT's or MOSFET's, can be mounted on an etched copper circuit. Heat densities over 80 W/cm2 can be dissipated easily. The functionality is independent of the working position either horizontal or vertical. The heat pipe can be used to an internal pressure over 7 bars without cracking the ceramic substrate. All requirements for space applications could be fulfilled. First application is foreseen for cooling DC-DC converters in satellites

Dbc (direct bond copper) substrate with integrated flat heat pipe

This paper presents the conception and the experimental procedures of flat copper heat pipe embedded in extremely thin 3D packaging substrates. Since conventional machining for this application is very complicated and expensive, the DBC (Directed Bonded Copper) technology proved to be more interesting for mass production. The experimental results demonstrated that the DBC heat pipe is an excellent solution to enhance the heat transfer within the 3D packaging.

J. Schulz-Harder

Papers

Heat Pipe Integrated in Direct Bonded Copper (DBC) Technology for Cooling of Power Electronics Packaging

Heat Pipe Integrated in Direct Bonded Copper (DBC) Technology for the Cooling of Power Electronics Packaging

Dbc (direct bond copper) substrate with integrated flat heat pipe

DBC Technology for Extremely Thin Flat Heat Pipes

DBC Technology for Extremely Flat Heat Pipe