M. Pecht - Academia.edu (original) (raw)
Conference Papers - 2007 by M. Pecht
— This paper presents an enhanced prognostic model to predict remaining useful life. The model ut... more — This paper presents an enhanced prognostic model to predict remaining useful life. The model utilizes environmental loads and in-situ performance measurements in conjunction with two baseline prediction algorithms: life consumption monitoring (LCM) and uncertainty adjusted prognostics (UAP). Fusion techniques are then utilized to integrate the two prognostic algorithms. A key and unique value of this combined prognostic model is its ability to assess intermittent as well as " hard " failures. In the paper we show how it has been validated for intermittent and " hard " solder joint interconnect failures under temperature cycling loads. 1
Papers by M. Pecht
2012 13th International Conference on Electronic Packaging Technology & High Density Packaging, 2012
ABSTRACT This paper presents an investigation into the reliability and physical degradation mecha... more ABSTRACT This paper presents an investigation into the reliability and physical degradation mechanisms associated with the loss of battery performance. Cells from two different manufactures underwent cycle life testing until failure (defined as a 20% decrease in nominal capacity). Designated samples from each battery type were subjected to one of two different discharge methods, one at a constant discharge rate of 1C and the other at a constant discharge rate of 0.5C. A third group of batteries were collected and examined after undergoing catastrophic failure in field applications. The tape pull test (to test adhesion/cohesion of electrode material to current collectors) is introduced for the first time in battery literature. Other analysis techniques such as x-ray imaging and environmental scanning electron microscopy were used to investigate the structural and chemical degradation of all the samples. Statistical analysis was performed on the cycle life data to evaluate battery reliability.
2005 7th Electronic Packaging Technology Conference
Tin whiskering is a concern with high tin finishes on electronic part terminations. Solder-dippin... more Tin whiskering is a concern with high tin finishes on electronic part terminations. Solder-dipping is being used as a method for replacing the original finish with eutectic tin-lead solder, as a tin whisker risk mitigation method. The solder-dipping process however, may expose the electronic parts to additional risks due to the the finish quality and thermal shock produced by the
2007 8th International Conference on Electronic Packaging Technology, 2007
Reliability is the ability of a product or system to perform as intended (i.e., without failure a... more Reliability is the ability of a product or system to perform as intended (i.e., without failure and within specified performance limits) for a specified time, in its life-cycle environment. Commonly-used electronics reliability prediction methods (e.g. Mil-HDBK-217, 217-PLUS, PRISM, Telcordia, FIDES) based on handbook methods have been shown to be misleading and provide erroneous life predictions, a fact that led the U. S. military to abandon their electronics reliability prediction methods. The use of stress and damage models permits a far superior accounting of the reliability and the physics-of-failure, however sufficient knowledge of the actual operating and environmental application conditions of the product are still required. This paper presents a physics-of-failure based prognostics and health management approach for effective reliability prediction. The procedure includes failure modes, mechanisms, and effects analysis, data reduction and feature extraction from the life cycle loads, damage accumulation, and assessment of uncertainty.
2008 International Conference on Electronic Packaging Technology & High Density Packaging, 2008
Handbook of Performability Engineering
IEEE Transactions on Device and Materials Reliability, 2012
IEEE Transactions on Components and Packaging Technologies, 2009
Measurements based on DC resistance have traditionally been used to monitor the reliability of el... more Measurements based on DC resistance have traditionally been used to monitor the reliability of electronic products. Unfortunately, DC resistance is not useful for detecting intermediate stages between a short and an open, such as a partially degraded interconnect. Under cyclic loading conditions, interconnect degradation is caused by fatigue cracking, which often initiates at the surface where the strain range is maximized. At high operating frequencies, signal propagation is concentrated at the circumferential region of an interconnect due to the skin effect. Therefore, RF impedance analysis offers a more sensitive means of detecting interconnect degradation than DC resistance. The skin effect also has implications for the reliability of electronics used in applications such as radar and telecommunications. The use of higher frequencies will make these circuits increasingly susceptible to performance degradation as a result of small cracks or deformation that would go unnoticed in ...
Journal of Intelligent Material Systems and Structures, 2011
This paper presents the application of model-based and data-driven approaches for prognostics of ... more This paper presents the application of model-based and data-driven approaches for prognostics of failures in embedded planar capacitors. An embedded planar capacitor is a thin laminate that serves both as a power/ground plane and as a parallel plate capacitor in a multilayered printed wiring board. These capacitors have gained importance with an increase in the operating frequency and a decrease in the supply voltage in electronic circuits since they can enable miniaturization of electronic circuits as well as improved electrical performance. In next generation electronic circuits, embedded planar capacitors will be crucial in communication, automotive, military, medical, and space applications. The capacitor laminate used in this study consisted of an epoxy-barium titanate nanocomposite dielectric sandwiched between Cu layers. Three electrical parameters, capacitance, dissipation factor, and insulation resistance, were monitored in situ during testing under elevated temperature and...
Microelectronics International, 1997
Plastic ball grid arrays (PBGAs) have been gaining increasing industry acceptance as potentially ... more Plastic ball grid arrays (PBGAs) have been gaining increasing industry acceptance as potentially the lowest cost packages for high pin count applications. The main factors for their success include the inherent low cost of plastic packages, the high yields achievable with existing assembly equipment, the density advantages of an area array and, in many cases, superior electrical performance. The reliability of these packages with respect to solder joint fatigue has been extensively studied; however, little has been published on their reliability with respect to moisture‐related failure mechanisms during assembly, such as popcorning. In this study, two types of plastic ball grid array packages, a 225‐lead full matrix array and a 256‐lead perimeter array, which were preconditioned by baking at 125°C for 24 hours followed by exposure to 85°C and 30% relative humidity for 168 hours, were then subjected to three passes of simulated infra‐red reflow at 1°C/s and 0.67°C/s. Subsequent exami...
To investigate the long term reliability of plastic ball grid array (PBGA) packages in aerospace ... more To investigate the long term reliability of plastic ball grid array (PBGA) packages in aerospace applications, accelerated tests were conducted to non-underfilled and underfilled packages under multiple environmental loadings at board level. This paper discusses the test results and the underfill effect on solder joint reliability. Failure modes and sites were identified through failure analysis on test samples. To better understand the thermomechanical behavior of PBGAs under cyclic thermal loading environments, three dimensional FEA models for non-underfilled and underfilled packages were also developed and used to predict the time to failure.
2008 2nd Electronics Systemintegration Technology Conference, 2008
ABSTRACT According to the European Directive 2002/95/EC RoHS solders that contain lead have to be... more ABSTRACT According to the European Directive 2002/95/EC RoHS solders that contain lead have to be replaced with lead-free equivalents. Replacing well-known materials with new materials not only force technological adaptations but also force necessity of reliability investigations, especially new failure modes. In case of lead-free solders, the main problem is reduction of solder joint strength. Lower strength of lead- free solder joint in comparison with SnPb is the result of defects that occur in the joint structure. Because of local defects, the joints are much more sensitive for stresses, Stress inducted within the area of solder joint can lead to joint fractures. Despite the crack occurrence, the solder joint can still conduct electrically. Nevertheless cracked joint should be treated as failed because it does not fulfill its constructional function. Such failures can be difficult to detect in static conditions, but can be easy detected, when the tested joint is subjected to vibrations. During vibrations short opens of the joint can occur. Additional high temperature or temperature cycles loadings can make detection easier by acceleration of crack occurrence. To detect short opens of solder joints subjected to vibrations, continuous fast measurements of resistance changes during the test are required. Within the article, the essence of fast multi-channel measurements and the construction of dedicated data storage system will be described. As a summary expected results of measurements will be shortly presented.
2011 Prognostics and System Health Managment Confernece, 2011
Abstract Rolling element bearing vibration signal is a modulated signal, and the existence of mod... more Abstract Rolling element bearing vibration signal is a modulated signal, and the existence of modulation increases the difficulty in bearing fault detection. Hilbert transform has been widely used in signal demodulation. However, the endpoint effect often makes the result unsatisfactory. Further, bearing vibration signals are usually polluted by various noises at low frequency, and the analysis of high frequency can be more effective for bearing fault feature extraction. This paper proposes an improved method that combines the energy ...
2011 Prognostics and System Health Managment Confernece, 2011
Soldering & Surface Mount Technology, 1996
Two types of Plastic ball Grid array packages, a 225‐lead full matrix array and a 256‐lead perime... more Two types of Plastic ball Grid array packages, a 225‐lead full matrix array and a 256‐lead perimeter array, were subjected to 168 hours of moisture preconditioning at 85°C and 30% relative humidity followed by simulated infra‐red reflow at temperature ramp rates of 1°C/s and 0.67°C/s. The packages were subsequently examined for delamination and cracking using scanning acoustic microscopy and environmental scanning electron microscopy. At the higher ramp rate, delamination and cracking were observed in both package types, originating in the die attach and propagating along the weakest interfaces. At the lower ramp rate, a small amount of delamination was observed. This suggests that there is a critical ramp rate below which popcorn cracking does not occur.
Journal of Electronic Packaging, 1990
The combined effects of elastic and inelastic strains on solder joint reliability are investigate... more The combined effects of elastic and inelastic strains on solder joint reliability are investigated. Experimental data from high-cycle fatigue tests of solder are combined with data from low-cycle fatigue tests to obtain a plot of total strain amplitude against cycles to failure. The generalized Coffin-Manson fatigue equation is used to describe this relationship. The transition fatigue life of approximately 7000 cycles indicates that elastic strains play a significant role in the fatigue damage of solders at a life of 103 cycles or higher. The results suggest that the commonly adopted approach of relating only inelastic strain, or the total strain, to fatigue life with a single power law relationship may be inadequate when predicting solder joint reliability. Instead, both elastic strains and plastic strains should be considered, especially when the electronic assembly is subjected to a combination of large amplitude thermal loads and relatively lower amplitude vibrational loads. A ...
Journal of Electronic Packaging, 1992
This study explores the possibility of using a unified theory of creep-fatigue, similar to the Ha... more This study explores the possibility of using a unified theory of creep-fatigue, similar to the Halford-Manson strain-range partitioning method, for examining the effect of cyclic temperature range on fatigue life, over a wide range of temperatures. Other investigators have attempted similar techniques before for solder fatigue analysis. The present study is different since it proposes an energy-partitioning technique rather than strain-partitioning to examine the dependence of solder fatigue behavior on temperature dependent changes in the relative amounts of plastic and creep strains. The solder microstructure also dictates creep behavior but is assumed to be a given invariant parameter in this study. In other words, this study is targeted at as-cast microstructures and does not address post-recrystallization behavior. A sample solder joint of axisymmetric configuration, commonly found in leaded through-hole mounting technology, is analyzed with the help of nonlinear finite element...
This paper presents our recent study on the mechanical behavior of conductive elastomer buttons u... more This paper presents our recent study on the mechanical behavior of conductive elastomer buttons used as interconnects for LGA/BGA (Land Grid Array/Ball Grid Array) package assemblies. Stiffness measurements and contact force relaxation measurements were performed In consideration of the actual operating conditions of the sockets, the effects of both environmental temperature and initial contact force on the contact force relaxation behaviors of the conductive elastomer buttons were investigated. The results show that temperature, rather than initial contact force, plays a dominant role in determining the long-term relaxation behavior of conductive elastomer buttons.
IEEE Transactions on Reliability, 1991
— This paper presents an enhanced prognostic model to predict remaining useful life. The model ut... more — This paper presents an enhanced prognostic model to predict remaining useful life. The model utilizes environmental loads and in-situ performance measurements in conjunction with two baseline prediction algorithms: life consumption monitoring (LCM) and uncertainty adjusted prognostics (UAP). Fusion techniques are then utilized to integrate the two prognostic algorithms. A key and unique value of this combined prognostic model is its ability to assess intermittent as well as " hard " failures. In the paper we show how it has been validated for intermittent and " hard " solder joint interconnect failures under temperature cycling loads. 1
2012 13th International Conference on Electronic Packaging Technology & High Density Packaging, 2012
ABSTRACT This paper presents an investigation into the reliability and physical degradation mecha... more ABSTRACT This paper presents an investigation into the reliability and physical degradation mechanisms associated with the loss of battery performance. Cells from two different manufactures underwent cycle life testing until failure (defined as a 20% decrease in nominal capacity). Designated samples from each battery type were subjected to one of two different discharge methods, one at a constant discharge rate of 1C and the other at a constant discharge rate of 0.5C. A third group of batteries were collected and examined after undergoing catastrophic failure in field applications. The tape pull test (to test adhesion/cohesion of electrode material to current collectors) is introduced for the first time in battery literature. Other analysis techniques such as x-ray imaging and environmental scanning electron microscopy were used to investigate the structural and chemical degradation of all the samples. Statistical analysis was performed on the cycle life data to evaluate battery reliability.
2005 7th Electronic Packaging Technology Conference
Tin whiskering is a concern with high tin finishes on electronic part terminations. Solder-dippin... more Tin whiskering is a concern with high tin finishes on electronic part terminations. Solder-dipping is being used as a method for replacing the original finish with eutectic tin-lead solder, as a tin whisker risk mitigation method. The solder-dipping process however, may expose the electronic parts to additional risks due to the the finish quality and thermal shock produced by the
2007 8th International Conference on Electronic Packaging Technology, 2007
Reliability is the ability of a product or system to perform as intended (i.e., without failure a... more Reliability is the ability of a product or system to perform as intended (i.e., without failure and within specified performance limits) for a specified time, in its life-cycle environment. Commonly-used electronics reliability prediction methods (e.g. Mil-HDBK-217, 217-PLUS, PRISM, Telcordia, FIDES) based on handbook methods have been shown to be misleading and provide erroneous life predictions, a fact that led the U. S. military to abandon their electronics reliability prediction methods. The use of stress and damage models permits a far superior accounting of the reliability and the physics-of-failure, however sufficient knowledge of the actual operating and environmental application conditions of the product are still required. This paper presents a physics-of-failure based prognostics and health management approach for effective reliability prediction. The procedure includes failure modes, mechanisms, and effects analysis, data reduction and feature extraction from the life cycle loads, damage accumulation, and assessment of uncertainty.
2008 International Conference on Electronic Packaging Technology & High Density Packaging, 2008
Handbook of Performability Engineering
IEEE Transactions on Device and Materials Reliability, 2012
IEEE Transactions on Components and Packaging Technologies, 2009
Measurements based on DC resistance have traditionally been used to monitor the reliability of el... more Measurements based on DC resistance have traditionally been used to monitor the reliability of electronic products. Unfortunately, DC resistance is not useful for detecting intermediate stages between a short and an open, such as a partially degraded interconnect. Under cyclic loading conditions, interconnect degradation is caused by fatigue cracking, which often initiates at the surface where the strain range is maximized. At high operating frequencies, signal propagation is concentrated at the circumferential region of an interconnect due to the skin effect. Therefore, RF impedance analysis offers a more sensitive means of detecting interconnect degradation than DC resistance. The skin effect also has implications for the reliability of electronics used in applications such as radar and telecommunications. The use of higher frequencies will make these circuits increasingly susceptible to performance degradation as a result of small cracks or deformation that would go unnoticed in ...
Journal of Intelligent Material Systems and Structures, 2011
This paper presents the application of model-based and data-driven approaches for prognostics of ... more This paper presents the application of model-based and data-driven approaches for prognostics of failures in embedded planar capacitors. An embedded planar capacitor is a thin laminate that serves both as a power/ground plane and as a parallel plate capacitor in a multilayered printed wiring board. These capacitors have gained importance with an increase in the operating frequency and a decrease in the supply voltage in electronic circuits since they can enable miniaturization of electronic circuits as well as improved electrical performance. In next generation electronic circuits, embedded planar capacitors will be crucial in communication, automotive, military, medical, and space applications. The capacitor laminate used in this study consisted of an epoxy-barium titanate nanocomposite dielectric sandwiched between Cu layers. Three electrical parameters, capacitance, dissipation factor, and insulation resistance, were monitored in situ during testing under elevated temperature and...
Microelectronics International, 1997
Plastic ball grid arrays (PBGAs) have been gaining increasing industry acceptance as potentially ... more Plastic ball grid arrays (PBGAs) have been gaining increasing industry acceptance as potentially the lowest cost packages for high pin count applications. The main factors for their success include the inherent low cost of plastic packages, the high yields achievable with existing assembly equipment, the density advantages of an area array and, in many cases, superior electrical performance. The reliability of these packages with respect to solder joint fatigue has been extensively studied; however, little has been published on their reliability with respect to moisture‐related failure mechanisms during assembly, such as popcorning. In this study, two types of plastic ball grid array packages, a 225‐lead full matrix array and a 256‐lead perimeter array, which were preconditioned by baking at 125°C for 24 hours followed by exposure to 85°C and 30% relative humidity for 168 hours, were then subjected to three passes of simulated infra‐red reflow at 1°C/s and 0.67°C/s. Subsequent exami...
To investigate the long term reliability of plastic ball grid array (PBGA) packages in aerospace ... more To investigate the long term reliability of plastic ball grid array (PBGA) packages in aerospace applications, accelerated tests were conducted to non-underfilled and underfilled packages under multiple environmental loadings at board level. This paper discusses the test results and the underfill effect on solder joint reliability. Failure modes and sites were identified through failure analysis on test samples. To better understand the thermomechanical behavior of PBGAs under cyclic thermal loading environments, three dimensional FEA models for non-underfilled and underfilled packages were also developed and used to predict the time to failure.
2008 2nd Electronics Systemintegration Technology Conference, 2008
ABSTRACT According to the European Directive 2002/95/EC RoHS solders that contain lead have to be... more ABSTRACT According to the European Directive 2002/95/EC RoHS solders that contain lead have to be replaced with lead-free equivalents. Replacing well-known materials with new materials not only force technological adaptations but also force necessity of reliability investigations, especially new failure modes. In case of lead-free solders, the main problem is reduction of solder joint strength. Lower strength of lead- free solder joint in comparison with SnPb is the result of defects that occur in the joint structure. Because of local defects, the joints are much more sensitive for stresses, Stress inducted within the area of solder joint can lead to joint fractures. Despite the crack occurrence, the solder joint can still conduct electrically. Nevertheless cracked joint should be treated as failed because it does not fulfill its constructional function. Such failures can be difficult to detect in static conditions, but can be easy detected, when the tested joint is subjected to vibrations. During vibrations short opens of the joint can occur. Additional high temperature or temperature cycles loadings can make detection easier by acceleration of crack occurrence. To detect short opens of solder joints subjected to vibrations, continuous fast measurements of resistance changes during the test are required. Within the article, the essence of fast multi-channel measurements and the construction of dedicated data storage system will be described. As a summary expected results of measurements will be shortly presented.
2011 Prognostics and System Health Managment Confernece, 2011
Abstract Rolling element bearing vibration signal is a modulated signal, and the existence of mod... more Abstract Rolling element bearing vibration signal is a modulated signal, and the existence of modulation increases the difficulty in bearing fault detection. Hilbert transform has been widely used in signal demodulation. However, the endpoint effect often makes the result unsatisfactory. Further, bearing vibration signals are usually polluted by various noises at low frequency, and the analysis of high frequency can be more effective for bearing fault feature extraction. This paper proposes an improved method that combines the energy ...
2011 Prognostics and System Health Managment Confernece, 2011
Soldering & Surface Mount Technology, 1996
Two types of Plastic ball Grid array packages, a 225‐lead full matrix array and a 256‐lead perime... more Two types of Plastic ball Grid array packages, a 225‐lead full matrix array and a 256‐lead perimeter array, were subjected to 168 hours of moisture preconditioning at 85°C and 30% relative humidity followed by simulated infra‐red reflow at temperature ramp rates of 1°C/s and 0.67°C/s. The packages were subsequently examined for delamination and cracking using scanning acoustic microscopy and environmental scanning electron microscopy. At the higher ramp rate, delamination and cracking were observed in both package types, originating in the die attach and propagating along the weakest interfaces. At the lower ramp rate, a small amount of delamination was observed. This suggests that there is a critical ramp rate below which popcorn cracking does not occur.
Journal of Electronic Packaging, 1990
The combined effects of elastic and inelastic strains on solder joint reliability are investigate... more The combined effects of elastic and inelastic strains on solder joint reliability are investigated. Experimental data from high-cycle fatigue tests of solder are combined with data from low-cycle fatigue tests to obtain a plot of total strain amplitude against cycles to failure. The generalized Coffin-Manson fatigue equation is used to describe this relationship. The transition fatigue life of approximately 7000 cycles indicates that elastic strains play a significant role in the fatigue damage of solders at a life of 103 cycles or higher. The results suggest that the commonly adopted approach of relating only inelastic strain, or the total strain, to fatigue life with a single power law relationship may be inadequate when predicting solder joint reliability. Instead, both elastic strains and plastic strains should be considered, especially when the electronic assembly is subjected to a combination of large amplitude thermal loads and relatively lower amplitude vibrational loads. A ...
Journal of Electronic Packaging, 1992
This study explores the possibility of using a unified theory of creep-fatigue, similar to the Ha... more This study explores the possibility of using a unified theory of creep-fatigue, similar to the Halford-Manson strain-range partitioning method, for examining the effect of cyclic temperature range on fatigue life, over a wide range of temperatures. Other investigators have attempted similar techniques before for solder fatigue analysis. The present study is different since it proposes an energy-partitioning technique rather than strain-partitioning to examine the dependence of solder fatigue behavior on temperature dependent changes in the relative amounts of plastic and creep strains. The solder microstructure also dictates creep behavior but is assumed to be a given invariant parameter in this study. In other words, this study is targeted at as-cast microstructures and does not address post-recrystallization behavior. A sample solder joint of axisymmetric configuration, commonly found in leaded through-hole mounting technology, is analyzed with the help of nonlinear finite element...
This paper presents our recent study on the mechanical behavior of conductive elastomer buttons u... more This paper presents our recent study on the mechanical behavior of conductive elastomer buttons used as interconnects for LGA/BGA (Land Grid Array/Ball Grid Array) package assemblies. Stiffness measurements and contact force relaxation measurements were performed In consideration of the actual operating conditions of the sockets, the effects of both environmental temperature and initial contact force on the contact force relaxation behaviors of the conductive elastomer buttons were investigated. The results show that temperature, rather than initial contact force, plays a dominant role in determining the long-term relaxation behavior of conductive elastomer buttons.
IEEE Transactions on Reliability, 1991
IEEE Transactions on Device and Materials Reliability, 2010
Stress relaxation in stamped metal LGA sockets can result in a loss of normal force and an increa... more Stress relaxation in stamped metal LGA sockets can result in a loss of normal force and an increase in contact resistance, potentially leading to a failure. This paper describes an approach for determining the risks from stress relaxation in stamped metal LGA sockets by taking into account the effect of Joule heating of the socket contacts. Stress relaxation data were