Numerical Thermal Simulation of Cryogenic Power Modules Under Liquid Nitrogen Cooling

2005 ◽  
Vol 128 (3) ◽  
pp. 267-272 ◽  
Author(s):  
Hua Ye ◽  
Harry Efstathiadis ◽  
Pradeep Haldar

Understanding the thermal performance of power modules under liquid nitrogen cooling is important for the design of cryogenic power electronic systems. When the power device is conducting electrical current, heat is generated due to Joule heating. The heat needs to be efficiently dissipated to the ambient in order to keep the temperature of the device within the allowable range; on the other hand, it would be advantageous to boost the current levels in the power devices to the highest possible level. Projecting the junction temperature of the power module during cryogenic operation is a crucial step in designing the system. In this paper, we present the thermal simulations of two different types of power metal-oxide semiconductor field effect transistor modules used to build a cryogenic inverter under liquid nitrogen pool cooling and discussed their implications on the design of the system.

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000289-000296 ◽  
Author(s):  
James D. Scofield ◽  
J. Neil Merrett ◽  
James Richmond ◽  
Anant Agarwal ◽  
Scott Leslie

A custom multi-chip power module packaging was designed to exploit the electrical and thermal performance potential of silicon carbide MOSFETs and JBS diodes. The dual thermo-mechanical package design was based on an aggressive 200°C ambient environmental requirement and 1200 V blocking and 100 A conduction ratings. A novel baseplate-free module design minimizes thermal impedance and the associated device junction temperature rise. In addition, the design incorporates a free-floating substrate configuration to minimize thermal expansion coefficient induced stresses between the substrate and case. Details of the module design and materials selection process will be discussed in addition to highlighting deficiencies in current packaging materials technologies when attempting to achieve high thermal cycle life reliability over an extended temperature range.


2012 ◽  
Vol 717-720 ◽  
pp. 1233-1236 ◽  
Author(s):  
Kohei Matsui ◽  
Yusuke Zushi ◽  
Yoshinori Murakami ◽  
Satoshi Tanimoto ◽  
Shinji Sato

We have developed a small-volume, high-power-output inverter with a high output power density using SiC power devices. To fully utilize the advantages of SiC power devices, it is necessary to reduce the inductance of the power module. This is done by using a double-layer ceramic substrate, attaining a low inductance of 5 nH. A double pulse test was carried out up to 60 A under a DC voltage of 600 V. The low inductance greatly reduced the surge voltage and the oscillation at the switching transient. The SiC inverter with a volume of 250 cc was assembled using three of the power modules. The cooling performance of the inverter was evaluated at a loss equivalent to an output power of 10 kW, and it was found that the inverter can output 10 kW at a junction temperature (Tj) of about 200°C.


Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1060
Author(s):  
Min-Ki Kim ◽  
Sang Won Yoon

In this paper, an approach to determine the thermal impedance of a multi-chip silicon carbide (SiC) power module is proposed, by fusing optical measurement and multi-physics simulations. The tested power module consists of four parallel SiC metal-oxide semiconductor field-effect transistors (MOSFETs) and four parallel SiC Schottky barrier diodes. This study mainly relies on junction temperature measurements performed using fiber optic temperature sensors instead of temperature-sensitive electrical parameters (TESPs). However, the fiber optics provide a relatively slow response compared to other available TSEP measurement methods and cannot detect fast responses. Therefore, the region corresponding to undetected signals is estimated via multi-physics simulations of the power module. This method provides a compensated cooling curve. We analyze the thermal resistance using network identification by deconvolution (NID). The estimated thermal resistance is compared to that obtained via a conventional method, and the difference is 3.8%. The proposed fusion method is accurate and reliable and does not require additional circuits or calibrations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zoubir Khatir ◽  
Son-Ha Tran ◽  
Ali Ibrahim ◽  
Richard Lallemand ◽  
Nicolas Degrenne

AbstractExperimental investigations on the effects of load sequence on degradations of bond-wire contacts of Insulated Gate Bipolar Transistors power modules are reported in this paper. Both the junction temperature swing ($$\Delta T_{j}$$ Δ T j ) and the heating duration ($$t_{ON}$$ t ON ) are investigated. First, power cycling tests with single conditions (in $$\Delta T_{j}$$ Δ T j and $$t_{ON}$$ t ON ), are performed in order to serve as test references. Then, combined power cycling tests with two-level stress conditions have been done sequentially. These tests are carried-out in the two sequences: low stress/high stress (LH) and high stress/low stress (HL) for both $$\Delta T_{j}$$ Δ T j and $$t_{ON}$$ t ON . The tests conducted show that a sequencing in $$\Delta T_{j}$$ Δ T j regardless of the direction “high-low” or “low–high” leads to an acceleration of degradations and so, to shorter lifetimes. This is more pronounced when the difference between the stress levels is large. With regard to the heating duration ($$t_{ON}$$ t ON ), the effect seems insignificant. However, it is necessary to confirm the effect of this last parameter by additional tests.


2018 ◽  
Vol 36 (6) ◽  
pp. 1609-1628 ◽  
Author(s):  
Chengzheng Cai ◽  
Feng Gao ◽  
Yugui Yang

Liquid nitrogen is a type of super-cryogenic fluid, which can cause the reservoir temperature to decrease significantly and thereby induce formation rock damage and cracking when it is injected into the wellbore as fracturing fluid. An experimental set-up was designed to monitor the acoustic emission signals of coal during its contact with cryogenic liquid nitrogen. Ultrasonic and tensile strength tests were then performed to investigate the effect of liquid nitrogen cooling on coal cracking and the changes in mechanical properties thereof. The results showed that acoustic emission phenomena occurred immediately as the coal sample came into contact with liquid nitrogen. This indicated that evident damage and cracking were induced by liquid nitrogen cooling. During liquid nitrogen injection, the ring-down count rate was high, and the cumulative ring-down counts also increased rapidly. Both the ring-down count rate and the cumulative ring-down counts during liquid nitrogen injection were much greater than those in the post-injection period. Liquid nitrogen cooling caused the micro-fissures inside the coal to expand, leading to a decrease in wave velocity and the deterioration in mechanical strength. The wave velocity, which was measured as soon as the sample was removed from the liquid nitrogen (i.e. the wave velocity was recorded in the cooling state), decreased by 14.46% on average. As the cryogenic samples recovered to room temperature, this value increased to 18.69%. In tensile strength tests, the tensile strengths of samples in cooling and cool-treated states were (on average) 17.39 and 31.43% less than those in initial state. These indicated that both during the cooling and heating processes, damage and cracking were generated within these coal samples, resulting in the acoustic emission phenomenon as well as the decrease in wave velocity and tensile strength.


2011 ◽  
Vol 324 ◽  
pp. 437-440
Author(s):  
Raed Amro

There is a demand for higher junction temperatures in power devices, but the existing packaging technology is limiting the power cycling capability if the junction temperature is increased. Limiting factors are solder interconnections and bond wires. With Replacing the chip-substrate soldering by low temperature joining technique, the power cycling capability of power modules can be increased widely. Replacing also the bond wires and using a double-sided low temperature joining technique, a further significant increase in the life-time of power devices is achieved.


2021 ◽  
Author(s):  
Hayden Carlton ◽  
John Harris ◽  
Alexis Krone ◽  
David Huitink ◽  
Md Maksudul Hossain ◽  
...  

Abstract The need for high power density electrical converters/inverters dominates the power electronics realm, and wide bandgap semiconducting materials, such as gallium nitride (GaN), provide the enhanced material properties necessary to drive at higher switching speeds than traditional silicon. However, lateral GaN devices introduce packaging difficulties, especially when attempting a double-sided cooled solution. Herein, we describe optimization efforts for a 650V/30A, GaN half-bridge power module with an integrated gate driver and double-sided cooling capability. Two direct bonded copper (DBC) substrates provided the primary means of heat removal from the module. In addition to the novel topology, the team performed electrical/thermal co-design to increase the multi-functionality of module. Since a central PCB comprised the main power loop, the size and geometry of the vias and copper traces was analyzed to determine optimal functionality in terms of parasitic inductance and thermal spreading. Thermally, thicker copper layers and additional vias introduced into the PCB also helped reduce hot spots within the module. Upon fabrication of the module, it underwent electrical characterization to determine switching performance, as well as thermal characterization to experimentally measure the total module’s thermal resistance. The team successfully operated the module at 400 V, 30 A with a power loop parasitic inductance of 0.89 nH; experimental thermal measurements also indicated the module thermal resistance to be 0.43 C/W. The overall utility of the design improved commensurately by introducing simple, yet effective electrical/thermal co-design strategies, which can be applied to future power modules.


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