scholarly journals Review of Methodologies for Structural Integrity Evaluation of Power Modules

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Noriyuki Miyazaki ◽  
Nobuyuki Shishido ◽  
Yutaka Hayama
Keyword(s):  
Thermal Fatigue ◽  
Structural Integrity ◽  
Strain Range ◽  
Inelastic Strain ◽  
Test Methods ◽  
Power Module ◽  
Cycling Test ◽  
Die Attach ◽  
Power Modules ◽  
Failure Models

Abstract This paper reviews the previous research on the methodologies for evaluating structural integrity of wire bonds and die-attachments in power modules. Under power module operation, these parts are subjected to repeated temperature variations which induce repeated thermal stress due to the mismatch in coefficients of thermal expansion (CTE) of the constituent materials. Thus, thermal fatigue phenomena are critical issues for the structural integrity of power modules. In the present paper, we also deal with the evaluation methodologies for thermal fatigue in the temperatures over 200 °C, which are expected operational temperatures for wide bandgap semiconductor power modules. The failure models based on the temperature range ΔT widely used in the power electronics community are critically reviewed from a mechanical engineering viewpoint. Detailed discussion is given concerning the superiority of failure models based on the physical quantities such as the inelastic strain range Δεin, the inelastic strain energy density range ΔWin, and the nonlinear fracture mechanics parameter range ΔT* over the conventional ΔT-based failure models. It is also pointed out that the distributed state concept (DSC) approaches based on the unified constitutive modeling and the unified mechanics theory are promising for evaluating the structural integrity of power modules. Two kinds of test methods, a power cycling test (PCT) and a thermal cycling test (TCT), are discussed in the relation to evaluating the lifetimes of wire-liftoff and die attach cracking.

Precision Evaluation for Thermal Fatigue Life of Power Module Using Coupled Electrical-Thermal-Structural Analysis

2011 ◽  
Author(s):  
Tomohiro Takahashi ◽  
Qiang Yu ◽  
Masahiro Kobayashi
Keyword(s):  
Fatigue Life ◽  
Temperature Distribution ◽  
Solder Joint ◽  
Thermal Fatigue ◽  
Thermal Structure ◽  
Inelastic Strain ◽  
Power Module ◽  
Thermal Fatigue Life ◽  
Power Cycling ◽  
Precision Evaluation

For power module, the reliability evaluation of thermal fatigue life by power cycling has been prioritized as an important concern. Since in power cycling produces there exists non-uniform temperature distribution in the power module, coupled thermal-structure analysis is required to evaluate thermal fatigue mechanism. The thermal expansion difference between a Si chip and a substrate causes thermal fatigue. In this study, thermal fatigue life of solder joints on power module was evaluated. The finite element method (FEM) was used to evaluate temperature distribution induced by joule heating. Higher temperature appears below the Al wire because the electric current flows through the bonding Al wire. Coupled thermal-structure analysis is also required to evaluate the inelastic strain distribution. The damage of each part of solder joint can be calculated from equivalent inelastic strain range and crack propagation was simulated by deleting damaged elements step by step. The initial cracks were caused below the bonding Al wire and propagated concentrically under power cycling. There is the difference from environmental thermal cycling where the crack initiated at the edge of solder layer. In addition, in order to accurately evaluate the thermal fatigue life, the factors affecting the thermal fatigue life of solder joint where verified using coupled electrical-thermal-structural analysis. Then, the relation between the thermal fatigue life of solder joint and each factor is clarified. The precision evaluation for the thermal fatigue life of power module is improved.

scholarly journals Thermal Assessment and In-Situ Monitoring of Insulated Gate Bipolar Transistors in Power Electronic Modules

2019 ◽  
Author(s):  
Erick Gutierrez ◽  
Kevin Lin ◽  
Douglas DeVoto ◽  
Patrick McCluskey
Keyword(s):  
Thermal Cycling ◽  
Failure Modes ◽  
Rapid Determination ◽  
Degradation Process ◽  
In Situ Monitoring ◽  
Power Module ◽  
Insulated Gate Bipolar Transistor ◽  
Die Attach ◽  
Power Modules

Abstract Insulated gate bipolar transistor (IGBT) power modules are devices commonly used for high-power applications. Operation and environmental stresses can cause these power modules to progressively degrade over time, potentially leading to catastrophic failure of the device. This degradation process may cause some early performance symptoms related to the state of health of the power module, making it possible to detect reliability degradation of the IGBT module. Testing can be used to accelerate this process, permitting a rapid determination of whether specific declines in device reliability can be characterized. In this study, thermal cycling was conducted on multiple power modules simultaneously in order to assess the effect of thermal cycling on the degradation of the power module. In-situ monitoring of temperature was performed from inside each power module using high temperature thermocouples. Device imaging and characterization were performed along with temperature data analysis, to assess failure modes and mechanisms within the power modules. While the experiment aimed to assess the potential damage effects of thermal cycling on the die attach, results indicated that wire bond degradation was the life-limiting failure mechanism.

Electromigration Analysis of Solder Joints for Power Modules Using an Electrical-Thermal-Stress Coupled Model

2021 ◽  
Author(s):  
Mitsuaki Kato ◽  
Takahiro Omori ◽  
Akihiro Goryu ◽  
Tomoya Fumikura ◽  
Kenji Hirohata
Keyword(s):  
Thermal Stress ◽  
Solder Joint ◽  
Power Output ◽  
Solder Joints ◽  
Vacancy Concentration ◽  
Inelastic Strain ◽  
Power Device ◽  
Power Module ◽  
Power Modules ◽  
Rate Of Increase

Abstract Power modules are being developed to increase power output. The larger current densities accompanying increased power output are expected to degrade solder joints in power modules by electromigration. In previous research, numerical analysis of solder for electromigration has mainly examined ball grid arrays in flip-chip packages in which many solder balls are bonded under the semiconductor device. However, in a power module, a single solder joint is uniformly bonded under the power device. Because of this difference in geometric shape, the effect of electromigration in the solder of power modules may be significantly different from that in the solder of flip chips packages. This report describes an electromigration analysis of solder joints for power modules using an electrical-thermal-stress coupled analysis. First, we validate our numerical implementation and show that it can reproduce the vacancy concentrations and hydrostatic stress almost the same as the analytical solutions. We then simulate a single solder joint to evaluate electromigration in a solder joint in a power module. Once inelastic strain appears, the rate of increase in vacancy concentration slows, while the inelastic strain continuously increases. This phenomenon demonstrates that elastic-plastic-creep analysis is crucial for electromigration analysis of solder joints in power modules. Next, the solder joint with a power device and a substrate as used in power modules was simulated. Plasticity-creep and longitudinal gradient generated by current crowding have a strong effect on significantly reducing the vacancy concentration at the anode edge over a long period of time.

Parametric and Sensitivity Analysis of Power Module Design

2019 ◽  
Author(s):  
L. M. Boteler ◽  
M. C. Fish ◽  
M. S. Berman
Keyword(s):  
Sensitivity Analysis ◽  
Heat Sink ◽  
Thermal Interface Materials ◽  
Power Module ◽  
Thermal Interface ◽  
Module Design ◽  
Die Attach ◽  
Power Modules ◽  
The Impact ◽  
Interface Materials

Abstract As technology becomes more electrified, thermal and power engineers need to know how to improve power modules to realize their full potential. Current power module technology involves planar ceramic-based substrates with wirebond interconnects and a detached heat sink. There are a number of well-known challenges with the current configuration including heat removal, reliability due to coefficient of thermal expansion (CTE) mismatch, and parasitic inductance. Various solutions have been proposed in literature to help solve many of these issues: alternate substrates, advanced thermal interface materials, compliant die attach, thermal ground planes, high performing heat sinks, superconducting copper, wirebondless configurations, etc. While each of these technologies have their merits, this paper will perform a holistic analysis on a power module and identify the impact of improving various technologies on the device temperature. Parametric simulations were performed to assess the impact of many aspects of power module design including material selection, device layout, and heat sink choice. Materials that have been investigated include die attach, substrate, heat spreader, and thermal interface materials. In all cases, the industry standard was compared to the state of the art to quantify the advantages and/or disadvantages of adopting the new technologies. A sensitivity analysis is also performed which shows how and where the biggest benefits could be realized when redesigning power modules and determining whether to integrate novel technologies.

The Development of High Thermal Conductivity SiC Power Modules through the Implementation of Advanced Cooling Techniques Coupled with High Heat Transfer Materials

2018 ◽  
Vol 924 ◽  
pp. 866-870
Author(s):  
Brandon Passmore ◽  
Brice McPherson ◽  
David Simco ◽  
Alex Lostetter
Keyword(s):  
Heat Transfer ◽  
High Heat ◽  
Power Module ◽  
Heat Spreader ◽  
Die Attach ◽  
High Heat Transfer ◽  
Power Modules ◽  
Recent Developments ◽  
Transfer Properties ◽  
Cooling Methods

This paper discusses Wolfspeed’s advances in silicon carbide (SiC) power module packaging, focusing on recent developments in advanced power module heat transfer techniques, the integration of pinfin mechanical structures, and the implementation of advanced die attach materials. Heat spreader materials and novel cooling methods suitable for SiC power modules are presented, focusing on the thermal heat transfer properties and a discussion of the design and prototype experimental impacts.

Analysis of Stress-Strain Hysteresis Loop and Prediction of Thermal Fatigue Life for Chip Size Package Solder Joints

2011 ◽  
Vol 462-463 ◽  
pp. 76-81
Author(s):  
Ikuo Shohji ◽  
Tatsuya Kobayashi ◽  
Tomotake Tohei
Keyword(s):  
Solder Joint ◽  
Thermal Fatigue ◽  
Solder Joints ◽  
Strain Range ◽  
Inelastic Strain ◽  
Hysteresis Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
Temperature Range ◽  
Chip Size

The aim of this study is to investigate the relationship between the inelastic strain range and the thermal fatigue lives of chip size package solder joints with Sn-Pb and Sn-Ag-Cu solder balls. The inelastic strain range was examined by finite element analysis. In both solder joints, the exponential terms in the inelastic strain range term in the Coffin-Manson equation were evaluated as 1.8 - 2.3. These values are very close to the conventional one used in Sn-Pb and the Pb containing solders. The inelastic strain range is almost proportional to the temperature range in the Sn-Pb solder joint. On the contrary, the inelastic strain range is proportional to approximately the square root of the temperature range in the Sn-Ag-Cu solder joint. The deference depends on the change of the stress-strain hysteresis curve in the thermal cycle.

Strengthening of DBA substrate with Ni/Ti/Ag metallization for thermal fatigue-resistant Ag sinter joining in GaN power modules

2020 ◽  
Vol 31 (4) ◽  
pp. 3715-3726 ◽  
Author(s):  
Dongjin Kim ◽  
Chuantong Chen ◽  
Seung-Joon Lee ◽  
Shijo Nagao ◽  
Katsuaki Suganuma
Keyword(s):  
Thermal Fatigue ◽  
Power Modules ◽  
Sinter Joining

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
Keyword(s):  
Liquid Nitrogen ◽  
Electrical Current ◽  
Oxide Semiconductor ◽  
Junction Temperature ◽  
Electronic Systems ◽  
Power Module ◽  
Power Modules ◽  
Allowable Range ◽  
Liquid Nitrogen Cooling ◽  
Thermal Simulations

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.

Thermal and Electrical Co-Optimization of a Multi-Chip Double-Sided Cooled GaN Module

2021 ◽  
Author(s):  
Hayden Carlton ◽  
John Harris ◽  
Alexis Krone ◽  
David Huitink ◽  
Md Maksudul Hossain ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Heat Removal ◽  
Electrical Characterization ◽  
Thermal Characterization ◽  
Design Strategies ◽  
Power Module ◽  
Parasitic Inductance ◽  
Switching Performance ◽  
Power Modules ◽  
Primary Means

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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