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.

Advanced Thermal Interface Materials

2006 ◽  
Vol 968 ◽  
Author(s):  
Yimin Zhang ◽  
Allison Xiao ◽  
Jeff McVey
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Energy ◽  
Heat Sink ◽  
Electronic Device ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Current State ◽  
Interface Materials ◽  
State Of Art

ABSTRACTThermal interface materials (TIMs) are used to dissipate thermal energy from a heat-generating device to a heat sink via conduction. The growing power density of the electronic device demands next-generation high thermal conductivity and/or low thermal resistance TIMs. This paper discusses the current state-of-art TIM solutions, particularly fusible particles for improved thermal conductivity. The paper will address the benefits and limitations of this approach, and describe a system with unique filler morphology. Thermal resistance and diffusivity/conductivity characterization techniques are also discussed.

Topological Design Optimization of Nested Channels for Squeeze Flow of Thermal Interface Materials

2010 ◽  
Author(s):  
Nikhil Bajaj ◽  
Ganesh Subbarayan ◽  
Suresh V. Garimella
Keyword(s):  
Sensitivity Analysis ◽  
Design Sensitivity ◽  
Topological Optimization ◽  
Surface Topology ◽  
Squeeze Flow ◽  
Thermal Interface Materials ◽  
Efficient Design ◽  
Thermal Interface ◽  
Resistance Network ◽  
Interface Materials

Thermal interface resistance remains a bottleneck for thermal transport in electronic systems, comprising a significant portion of overall system thermal resistance. Performance of thermal interface materials (TIMs) is largely dependent on the bulk thermal conductivity of the TIM but also on the bond-line thickness (BLT) of the applied material as well as interfacial contact resistances. Recently, Hierarchically Nested Channels (HNCs), created by modifying the surface topology with hierarchical arrangements of microchannels in order to improve flow, were proposed to reduce both required squeezing force and final BLTs in interfaces. In this paper, a topological optimization framework that enables the design of channel arrangements is developed. The framework is based on a resistance network approximation to Newtonian squeeze flow. The approximation, validated against finite element method (FEM)-based solutions, allows efficient, design-oriented solutions for squeeze flow in complex geometries. A comprehensive design sensitivity analysis exploiting the resistance network approximation is also developed and implemented. The resistance approximation and the sensitivity analysis is used to build an automated optimal channel design framework. A Pareto optimal problem formulation for the design of channels is posed and the optimal solution is demonstrated using the framework.

Thermal Performance Measurements of Thermal Interface Materials Using the Laser Flash Method

2007 ◽  
Author(s):  
Vinh Khuu ◽  
Michael Osterman ◽  
Avram Bar-Cohen ◽  
Michael Pecht
Keyword(s):  
Thermal Resistance ◽  
Thermal Performance ◽  
Heat Sink ◽  
Composite Structures ◽  
Laser Flash ◽  
Flash Method ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Layer Composite ◽  
Interface Materials

Thermal interface materials are used to reduce the interfacial thermal resistance between contacting surfaces inside electronic packages, such as at the die-heat sink or heat spreader-heat sink interfaces. In this study, the change in thermal performance was measured for elastomeric gap pads, gap fillers, and an adhesive throughout reliability tests. Three-layer composite structures were used to simulate loading conditions encountered by thermal interface materials in actual applications. The thermal resistance of the thermal interface material, including contact and bulk resistance, was calculated using the Lee algorithm, an iterative method that uses properties of the single layers and the 3-layer composite structures, measured using the laser flash method. Test samples were subjected to thermal cycling tests, which induced thermomechanical stresses due to the mismatch in the coefficients of thermal expansion of the dissimilar coupon materials. The thermal resistance measurements from the laser flash showed little change or slight improvement in the thermal performance over the course of temperature cycling. Scanning acoustic microscope images revealed delamination in one group of gap pad samples and cracking in the putty samples.

Bond Line Thickness of Thermal Interface Materials With Carbon Nanotubes

2005 ◽  
Author(s):  
Senthil A. G. Singaravelu ◽  
Xuejiao Hu ◽  
Kenneth E. Goodson
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Bond Line ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Line Thickness ◽  
Bond Line Thickness ◽  
The Impact ◽  
Interface Materials

Increasing power dissipation in today’s microprocessors demands thermal interface materials (TIMs) with lower thermal resistances. The TIM thermal resistance depends on the TIM thermal conductivity and the bond line thickness (BLT). Carbon Nanotubes (CNTs) have been proposed to improve the TIM thermal conductivity. However, the rheological properties of TIMs with CNT inclusions are not well understood. In this paper, the transient behavior of the BLT of the TIMs with CNT inclusions has been measured under controlled attachment pressures. The experimental results show that the impact of CNT inclusions on the BLT at low volume fractions (up to 2 vol%) is small; however, higher volume fraction of CNT inclusions (5 vol%) can cause huge increase in TIM thickness. Although thermal conductivities are higher for higher CNT fractions, a minimum TIM resistance exists at some optimum CNT fraction for a given attachment pressure.

Thermoelectric Heat Recovery From a Tankless Water Heating System

2008 ◽  
Author(s):  
S. A. LeBlanc ◽  
Y. Gao ◽  
K. E. Goodson
Keyword(s):  
Thermoelectric Material ◽  
System Integration ◽  
Waste Heat ◽  
Thermal Interface Materials ◽  
Water Heater ◽  
Thermal Interface ◽  
System Parameters ◽  
Material Parameters ◽  
The Impact ◽  
Interface Materials

Thermoelectric cogeneration promises to recover waste heat energy from a variety of combustion systems. There is a need for computationally efficient simulations of practical systems that allow optimization and illustrate the impact of key material and system parameters. Previous research investigated thermoelectric material enhancement and thermoelectric system integration separately. This work connects material parameters and system integration. We develop a thermal simulation for a 15kW tankless, methane-fueled water heater with thermoelectric modules embedded within a cross-flow heat exchanger. The simulation employs a finite volume method for the two fluids. It links external convection with a surface efficiency of 85%, internal convection for laminar flow, and conduction through the system in order to determine power generation within the thermoelectric. For a single pipe in the water heater system, 126 W of electrical power can be generated, and a typical system could yield 370 W. Realization of effective cogeneration systems hinges on investigating the impact of thermoelectric material parameters coupled with system parameters, so the impact of varying flow rate, convection coefficient, TEM thermal conductivity, Seebeck coefficient, and thermal interface materials are investigated. While varying parameters can improve thermoelectric output by over 50%, thermal interface materials can severely limit cogeneration system power output.

Review of Thermal Packaging Technologies for Automotive Power Electronics for Traction Purposes

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Justin Broughton ◽  
Vanessa Smet ◽  
Rao R. Tummala ◽  
Yogendra K. Joshi
Keyword(s):  
Silicon Carbide ◽  
Hybrid Electric Vehicles ◽  
Thermal Characteristics ◽  
Thermal Interface Materials ◽  
Liquid Cooling ◽  
Area Of Interest ◽  
Die Attach ◽  
Power Modules ◽  
Silicon Device ◽  
Interface Materials

Due to its superior electrical and thermal characteristics, silicon carbide power modules will soon replace silicon modules to be mass-produced and implemented in all-electric and hybrid-electric vehicles (HEVs). Redesign of the power modules will be required to take full advantage of these newer devices. A particular area of interest is high-temperature power modules, as under-hood temperatures often exceed maximum silicon device temperatures. This review will examine thermal packaging options for standard Si power modules and various power modules in recent all-electric and HEVs. Then, thermal packaging options for die-attach, thermal interface materials (TIM), and liquid cooling are discussed for their feasibility in next-generation silicon carbide (SiC) power modules.

Two-Medium Model for the Bond Line Thickness of Particle Filled Thermal Interface Materials

2004 ◽  
Author(s):  
Xuejiao Hu ◽  
Senthil Govindasamy ◽  
Kenneth E. Goodson
Keyword(s):  
Filler Particle ◽  
Bond Line ◽  
Thermal Interface Materials ◽  
Heterogeneous Structure ◽  
Thermal Interface ◽  
Line Thickness ◽  
Medium Model ◽  
Bond Line Thickness ◽  
The Impact ◽  
Interface Materials

Thermal interface materials (TIMs) are widely used in electronics packaging. Increasing heat generation rates require lower values of the TIM thermal resistance, which depends on the material thermal conductivity and the TIM thickness, or the bond line thickness (BLT). The variation of the TIM thickness is not well understood. The major difficulty comes from the complexity of TIMs as condensed particle systems, especially when the TIM thickness is squeezed to several multiples of the filler particle diameter. This confined heterogeneous structure makes the behavior of TIMs different from that of homogeneous fluids. In this study, we propose a two-medium model for the BLT. The variation of BLT with attachment pressure is modeled using two parameters: the viscidity of the fluids and the interactions of particles. The predictions are compared with the measurements for TIMs made of aluminum oxide particles (sizes: 0.6–6 microns, volume fractions: 30%–50%) and silicon oil (kinematic viscosity: 100 cst and 1000 cst). Reasonable agreement is obtained for different applied pressures. Results indicate that the impact of the particle interactions is an important factor governing the variation of the TIM BLT, especially when the BLT is small.

Reliability analysis of SnAgCu lead-free solder thermal interface materials in microelectronics

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mathias Ekpu
Keyword(s):  
Fatigue Life ◽  
Heat Sink ◽  
Flip Chip ◽  
Lead Free ◽  
Thermal Interface Materials ◽  
Lead Free Solder ◽  
Thermal Interface ◽  
Content Type ◽  
Free Solder ◽  
Interface Materials

Purpose In microelectronics industry, the reliability of its components is a major area of concern for engineers. Therefore, it is imperative that such concerns are addressed by using the most reliable materials available. Thermal interface materials (TIMs) are used in electronic devices to bridge the topologies that exists between a heat sink and the flip chip assembly. Therefore, this study aims to investigate the reliability of SAC405 and SAC396 in a microelectronics assembly. Design/methodology/approach In this paper, SnAgCu solder alloys (SAC405 and SAC396) were used as the TIMs. The model, which comprises the chip, TIM and heat sink base, was developed with ANSYS finite element analysis software and simulated under a thermal cycling load of between −40°C and 85°C. Findings The results obtained from this paper were based on the total deformation, stress, strain and fatigue life of the lead-free solder materials. The analyses of the results showed that SAC405 is more reliable than SAC396. This was evident in the fatigue life analysis where it was predicted that it took about 85 days for SAC405 to fail, whereas it took about 13 days for SAC396 to fail. Therefore, SAC405 is recommended as the TIM of choice compared to SAC396 based upon the findings of this investigation. Originality/value This paper is centred on SnAgCu solders used as TIMs. This paper demonstrated that SAC405 is a reliable solder TIM. This can guide manufacturers of electronic products in deciding which SAC solder to apply as TIM during the assembly process.

Effect of Temperature Cycling and High Temperature Aging on the Elastic Properties and Failure Modes of Thermal Interface Materials

2015 ◽  
Author(s):  
Taryn J. Davis ◽  
Tuhin Sinha ◽  
Ken Marston ◽  
Sushumna Iruvanti
Keyword(s):  
Thermal Performance ◽  
Failure Modes ◽  
Coefficient Of Thermal Expansion ◽  
Temperature Cycling ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Main Challenge ◽  
Cte Mismatch ◽  
The Impact ◽  
Interface Materials

Highly filled thermally conductive silicone gels are routinely used as first level thermal interface materials (TIMs) between the die and lid, in flip-chip organic packages. The main challenge for these TIMs is overcoming the Coefficient of Thermal Expansion (CTE) mismatch between the die and lid materials. The TIMs must maintain excellent adhesion to both the die and lid surfaces in order to achieve and maintain optimal thermal performance. The CTE mismatch leads to increased mechanical stress and degradation of the TIM, which in turn degrades the thermal performance. In this work, the effective modulus of several TIMs was calculated by finite element modeling (FEM) in concert with mechanical testing of thin bond-line aluminum-TIM sandwiches subjected to varied stress conditions. These results are correlated to the corresponding stress die shear testing and the impact on package performance is analyzed.

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