Warpage Evaluation of High-Temperature Sandwich-Structured Power Module for SiC Power Semiconductor Devices

2015 ◽  
Vol 12 (3) ◽  
pp. 153-160 ◽  
Author(s):  
Takeshi Anzai ◽  
Yoshinori Murakami ◽  
Shinji Sato ◽  
Hidekazu Tanisawa ◽  
Kohei Hiyama ◽  
...  

This article presents a sandwich-structured SiC power module that can be operated at 225°C. The proposed power module has two ceramic substrates that are made of different materials (Si3N4 and Al2O3). The SiC devices are sandwiched between these ceramic substrates. The module also has a baseplate soldered onto the ceramic substrate. Conventional power modules use baseplate materials with a large coefficient of thermal expansion (CTE), for example, Cu (17–18 ppm/°C and Al (23–24 ppm/°C). In the fabrication process, the soldering temperature reaches 450°C because Au-Ge eutectic solder is used. A problem was found in the fabrication process of the module because of the high soldering temperature and CTE mismatches of the components. Furthermore, for high-temperature operation, a thermal cycle of −40°C to 250°C will be needed to ensure reliability and it is important to decrease the warpage of the module during the thermal cycle. By using stainless steel (CTE: 10 ppm/°C) for the baseplate, the warp-age measured at room temperature was reduced to one-third that of a module using a Cu baseplate. Further, the warpage displacement from 50°C to 250°C was also reduced.

2014 ◽  
Vol 2014 (1) ◽  
pp. 000757-000762 ◽  
Author(s):  
Takeshi ANZAI ◽  
Yoshinori MURAKAMI ◽  
Shinji SATO ◽  
Hidekazu TANISAWA ◽  
Kohei HIYAMA ◽  
...  

A high temperature sandwich structured power module for high temperature SiC power semiconductor devices has been accomplished. Problems were found in the high temperature building-up process of the module caused by excess warpage of the ceramic substrate. Also the high temperature operation of the power module brings an excess warpage of the structure caused by parts having different coefficients of thermal expansion (CTEs) from each other. In this paper, some countermeasures to overcome the problems are demonstrated.


Author(s):  
Fumiki Kato ◽  
Hiroki Takahashi ◽  
Hidekazu Tanisawa ◽  
Kenichi Koui ◽  
Shinji Sato ◽  
...  

Abstract In this paper, we demonstrate that thermal degradation of silicon carbide (SiC) power modules corresponding to thermal cycles can be detected and tracked non-destructively by transient thermal analysis. The purpose of this evaluation is to analyze the distribution of the thermal resistance in the power module and to identify the structure deterioration part. As a target for evaluation power modules using a SiC-MOSFET for high-temperature operation were assembled with Zn-5Al eutectic solder. The junction to case thermal resistance was successfully evaluated as 0.85 K/W by using transient thermal analysis, and the thermal resistance of the Zn-5Al die-attachment was also evaluated as 0.13 K/W. A series of thermal cycle test between −40 and 250°C was conducted, and the power modules were evaluated their thermal resistance taken out from thermal cycle test machine at 100, 200, 500 and 1000 cycles. We identified the increase of thermal resistance each thermal cycle in specific modules. It was successfully shown that thermal resistance deterioration of SiC power module corresponding to thermal cycles can be traced non-destructively by this transient thermal analysis method.


2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000172-000179
Author(s):  
Michael J. Palmer ◽  
R. Wayne Johnson ◽  
Mohammad Motalab ◽  
Jeffrey Suhling ◽  
James D. Scofield

Silicon nitride (Si3N4) offer potential advantages as a substrate for high temperature power packaging. Si3N4 has higher fracture strength than alumina and aluminum nitride. The coefficient of thermal expansion (CTE) of Si3N4 is ~3 ppm/°C and the thermal conductivity ranges from 30–50W/m-K. Active metal brazed Cu-Si3N4 substrates are commercially available for power modules. However, the large mismatch in CTE between Si3N4 and Cu results in ceramic fracture and delamination with the wide temperature thermal cycling ranges encountered in high temperature applications. In this work Cu-Carbon and Cu-Mo metal matrix composites have been investigated to reduce the CTE mismatch. The process details are presented along with finite element modeling of the proposed structure. Ultimately, the proposed structure was unsuccessful.


2018 ◽  
Vol 86 (12) ◽  
pp. 107-112
Author(s):  
Fumiki Kato ◽  
Shinji Sato ◽  
Hidekazu Tanisawa ◽  
Kenichi Koui ◽  
Kinuyo Watanabe ◽  
...  

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000402-000406
Author(s):  
B. Passmore ◽  
J. Hornberger ◽  
B. McPherson ◽  
J. Bourne ◽  
R. Shaw ◽  
...  

A high temperature, high performance power module was developed for extreme environment systems and applications to exploit the advantages of wide bandgap semiconductors. These power modules are rated > 1200V, > 100A, > 250 °C, and are designed to house any SiC or GaN device. Characterization data of this power module housing trench MOSFETs is presented which demonstrates an on-state current of 1500 A for a full-bridge switch position. In addition, switching waveforms are presented that exhibit fast transition times.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000359-000364 ◽  
Author(s):  
Adam Morgan ◽  
Ankan De ◽  
Haotao Ke ◽  
Xin Zhao ◽  
Kasunaidu Vechalapu ◽  
...  

The main motivation of this work is to design, fabricate, test, and compare an alternative, robust packaging approach for a power semiconductor current switch. Packaging a high voltage power semiconductor current switch into a single power module, compared to using separate power modules, offers cost, performance, and reliability advantages. With the advent of Wide-Bandgap (WBG) semiconductors, such as Silicon-Carbide, singular power electronic devices, where a device is denoted as a single transistor or rectifier unit on a chip, can now operate beyond 10kV–15kV levels and switch at frequencies within the kHz range. The improved voltage blocking capability reduces the number of series connected devices within the circuit, but challenges power module designers to create packages capable of managing the electrical, mechanical, and thermal stresses produced during operation. The non-sinusoidal nature of this stress punctuated with extremely fast changes in voltage and current, with respect to time, leads to non-ideal electrical and thermal performance. An optimized power semiconductor series current switch is fabricated using an IGBT (6500V/25A die) and SiC JBS Diode (6000V/10A), packaged into a 3D printed housing, to create a composite series current switch package (CSCSP). The final chosen device configuration was simulated and verified in an ANSYS software package. Also, the thermal behavior of such a composite package was simulated and verified using COMSOL. The simulated results were then compared with empirically obtained data, in order to ensure that the thermal ratings of the power devices were not exceeded; directly affecting the maximum attainable frequency of operation for the CSCSP. Both power semiconductor series current switch designs are tested and characterized under hard switching conditions. Special attention is given to ensure the voltage stress across the devices is significantly reduced.


2017 ◽  
Vol 2017 (1) ◽  
pp. 000312-000317
Author(s):  
Adam Morgan ◽  
Xin Zhao ◽  
Jason Rouse ◽  
Douglas Hopkins

Abstract One of the most important advantages of wide-bandgap (WBG) devices is high operating temperature (>200°C). Power modules have been recognized as an enabling technology for many industries, such as automotive, deep-well drilling, and on-engine aircraft controls. These applications are all required to operate under some form of extreme environmental conditions. Silicone gels are the most popular solution for the encapsulation of power modules due to mechanical stress relief enabled by a low Young's modulus, electrical isolation achieved due to high dielectric strength, and a dense material structure that protects encapsulated devices against moisture, chemicals, contaminants, etc. Currently, investigations are focused on development of silicone gels with long-term high-temperature operational capability. The target is to elevate the temperature beyond 200°C to bolster adoption of power modules in the aforementioned applications. WACKER has developed silicone gels with ultra-high purity levels of < 2ppm of total residual ions combined with > 200°C thermal stability. In this work, leakage currents through a group of WACKER Chemie encapsulant silicone gels (A, B, C) are measured and compared for an array of test modules after exposure to a 12kV voltage sweep at room temperature up to 275°C, and thermal aging at 150°C for up to more than 700 hours. High temperature encapsulants capable of producing leakage currents less than 1μA, are deemed acceptable at the given applied blocking voltage and thermal aging soak temperature. To fully characterize the high temperature encapsulants, silicone gel A, B, and C, an entire high temperature module is used as a common test vehicle. The power module test vehicle includes: 12mil/40mil/12mil Direct Bonded Copper (DBC) substrates, gel under test (GUT), power and Kelvin connected measurement terminals, thermistor thermal sensor to sense real-time temperature, and 12mil Al bonding wires to manage localized high E-Fields around wires. It was ultimately observed that silicone gels B and C were capable of maintaining low leakage current capabilities under 12kV and 275°C conditions, and thus present themselves as strong candidates for high-temperature WBG device power modules and packaging.


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