Prognostic Health Monitoring of Damage Progression in Leadfree Electronics Under Sequential Exposure to Thermal Aging and Thermal Cycling

2010 ◽  
Author(s):  
Pradeep Lall ◽  
Rahul Vaidya ◽  
Vikrant More ◽  
Kai Goebel
Keyword(s):  
Thermal Cycling ◽  
Thermal Aging ◽  
Residual Life ◽  
High Reliability ◽  
Structural Evolution ◽  
Relative Accuracy ◽  
Percentage Error ◽  
Electronic Systems ◽  
Sample Standard Deviation ◽  
Reliability Systems

Deployed electronic systems may be subjected to cyclic thermo-mechanical loads during storage and subsequent to deployment. Aging has been previously shown to affect the reliability and constitutive behavior of second-level leadfree interconnects. Prognostication of accrued damage and assessment of residual life is extremely critical for ultra-high reliability systems in which the cost of failure is too high. The presented methodology uses leading indicators of failure based on micro-structural evolution of damage to identify impending failure in electronic systems subjected to sequential stresses of thermal aging and thermal cycling. The methodology has been demonstrated on area-array ball-grid array test assemblies with Sn3Ag0.5Cu interconnects subjected to thermal aging at 125°C and thermal cycling from −55 to 125°C for various lengths of time and cycles. Damage equivalency methodologies have been developed to map damage accrued in thermal aging to the reduction in thermo-mechanical cyclic life based on damage proxies. Prognostic metrics including α-λ metric, sample standard deviation, mean square error, mean absolute percentage error, average bias, relative accuracy, and cumulative relative accuracy have been used to compare the performance of the damage proxies.

Damage Pre-Cursors Based Prognostication of Accrued Damage and Assessment of Operational Readiness of Leadfree Electronics

2013 ◽  
Author(s):  
Pradeep Lall ◽  
Mahendra Harsha ◽  
Jeff Suhling ◽  
Kai Goebel
Keyword(s):  
Thermal Cycling ◽  
Microstructural Evolution ◽  
Thermal Aging ◽  
Prolonged Exposure ◽  
Residual Life ◽  
High Reliability ◽  
Electronic Systems ◽  
Damage Initiation ◽  
Aging Conditions ◽  
Insight Into

Electronics in high reliability applications may be stored for extended periods of time prior to deployment. Prior studies have shown the elastic modulus and ultimate tensile strength of the SAC leadfree alloys reduces under prolonged exposure to high temperatures [Zhang 2009]. The thermal cycle magnitudes may vary over the lifetime of the product. Long-life systems may be re-deployed several times over the use life of the product. Previously, the authors have identified damage pre-cursors for correlation of the damage progression with the microstructural evolution of damage in second level interconnects [Lall 2004a-d, 2005a-b, 2006a-f, 2007a-e, 2008a-f, 2009a-d, 2010a-j]. Leadfree assemblies with Sn3Ag0.5Cu solder have been subjected to variety of thermal aging conditions including 60°C, 85°C and 125°C for periods of time between 1-week and 2-months, thermal cycling from −55°C to 125°C, −40°C to 95°C and 3°C to 100°C. The presented methodology uses leading indicators of failure based on microstructural evolution of damage to identify accrued damage in electronic systems subjected to sequential stresses of thermal aging and thermal cycling. Damage equivalency relationships have been developed to map damage accrued in thermal aging to the reduction in thermo-mechanical cyclic life based on damage proxies. Accrued damage between different thermal cyclic magnitudes has also been mapped for from −55°C to 125°C, −40°C to 95°C and 3°C to 100°C thermal cycles. The presented method for interrogation of the accrued damage for the field deployed electronics, significantly prior to failure, may allow insight into the damage initiation and progression of the deployed system. The expected error with interrogation of system state and assessment of residual life has been quantified.

Accrued Damage and Remaining Life in Field Extracted Assemblies Under Sequential Thermo-Mechanical Loads

2011 ◽  
Author(s):  
Pradeep Lall ◽  
Mahendra Harsha ◽  
Jeff Suhling ◽  
Kai Goebel ◽  
Jim Jones
Keyword(s):  
Thermal Aging ◽  
Residual Life ◽  
Remaining Useful Life ◽  
Relative Accuracy ◽  
Percentage Error ◽  
Valuable Insight ◽  
Sample Standard Deviation ◽  
Damage Initiation ◽  
Useful Life ◽  
Insight Into

Field deployed electronics may accrue damage due to environmental exposure and usage after finite period of service but may not often have any macro-indicators of failure such as cracks or delamination. A method to interrogate the damage state of field deployed electronics in the pre-failure space may allow insight into the damage initiation, progression, and remaining useful life of the deployed system. Aging has been previously shown to effect the reliability and constitutive behavior of second-level leadfree interconnects. Prognostication of accrued damage and assessment of residual life can provide valuable insight into impending failure. In this paper, field deployed parts have been extracted and prognosticated for accrued damage and remaining useful life in an anticipated future deployment environment. A subset of the field deployed parts have been tested to failure in the anticipated field deployed environment to validate the assessment of remaining useful life. In addition, some parts have been subjected to additional know thermo-mechanical stresses and the incremental damage accrued validated with respect to the amount of additional damage imposed on the assemblies. The presented methodology uses leading indicators of failure based on micro-structural evolution of damage to identify accrued damage in electronic systems subjected to sequential stresses of thermal aging and thermal cycling. Damage equivalency methodologies have been developed to map damage accrued in thermal aging to the reduction in thermo-mechanical cyclic life based on damage proxies. The expected error with interrogation of system state and assessment of residual life has been quantified. Prognostic metrics including α-λ metric, sample standard deviation, mean square error, mean absolute percentage error, average bias, relative accuracy, and cumulative relative accuracy have been used to compare the performance of the damage proxies.

Physics of Failure Based Virtual Testing of Communications Hardware

2009 ◽  
Author(s):  
Elviz George ◽  
Diganta Das ◽  
Michael Osterman ◽  
Michael Pecht ◽  
Christopher Otte
Keyword(s):  
Thermal Cycling ◽  
High Reliability ◽  
Simulation Software ◽  
Circuit Board ◽  
Thermal Dissipation ◽  
Physics Of Failure ◽  
Printed Circuit ◽  
Operational Test ◽  
Reliability Systems ◽  
Cycles To Failure

Communications hardware for high reliability systems are starting to include modern low profile parts such as Quad Flat Pack No-lead (QFN) and Land Grid Array (LGA) packages to take advantage of their size and weight. In these parts, heat sinks often provide a conductive thermal dissipation path. Printed circuit assemblies with these parts will still need to meet the industry specific qualification requirements for thermal and vibration testing. It is beneficial to identify if the equipment will be able to meet the qualification test requirements during the design phase particularly when new technology insertions are being made. In this design, various surface mount packages like LGAs, QFNs and so on were used in a printed circuit board which included two stiffening layers with non-standard laminates. calcePWA is a simulation software which estimates the cycles to failure of components under various loading conditions using Physics of Failure (PoF). The cycles to failure simulation of this design using calcePWA software identified the critical interconnects that are at risk for failure under non-operational test conditions. The design was also evaluated under a long haul aircraft profile, with the assembly in operational state. In operational state simulation, the effectiveness of thermal shunts in reducing board to component thermal differentials was evaluated. Effects of degradations of the thermal shunts with time were used in the evaluation. Results showed that the vibration and shock reliability were less of a concern than thermal cycling for this board layout. Risk mitigation methods for thermal cycling durability were identified and recommended to be used in the system redesign.

HIGH RELIABILITY HIGH MELTING LEAD-FREE MIXED BIAGX SOLDER PASTE SYSTEM

2012 ◽  
Vol 2012 (1) ◽  
pp. 000119-000126 ◽  
Author(s):  
HongWen Zhang ◽  
Ning-Cheng Lee
Keyword(s):  
Thermal Cycling ◽  
Thermal Aging ◽  
High Reliability ◽  
Solder Paste ◽  
High Melting ◽  
Mixed Powder ◽  
Alloy Solder ◽  
Dislocation Movement ◽  
Melting Lead ◽  
High Lead

In the current work, a mixed solder powder BiAgX solder paste system with the melting temperature above 260°C and the comparable or even better reliability to the high lead solders has been studied. The mixed solder powder paste system is composed of a high melting first alloy solder powder as majority and the additive solder powder as minority. The additive solder is designed to react aggressively with various surface finish materials before or together with the melting of the majority solder to form a controllable IMC layer. The IMC layer of the mixed powder system is controllable by the species and the quantity of the additive solder and it is observed to be insensitive to thermal aging and thermal cycling in current tests while the high lead ones do show a considerable increase in IMC layer thickness. Microstructure investigation shows the fishbone shape IMC layer interlocks the bonding interface between solder and components. Both micron-sized and nano-sized Ag-rich precipitations in the joints have been observed to be well distributed in the joint. The exposed Ag-rich particles and the surrounding stepwise pattern in Bi matrix on the fracture surface indicate that these Ag-rich particles constrain the dislocation movement in Bi matrix thus enhance the strength and the ductility of the joint. Under thermal aging and thermal cycling, both the micron-sized and nano-sized Ag-rich precipitations exhibit only discernible and localized coarsening. The stable interfacial IMC together with the existence of the well dispersed Ag-rich particles are attributed to the promising reliability in BiAgX solder paste system.

scholarly journals Microstructure and shear properties of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal cycling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianguo Cui ◽  
Keke Zhang ◽  
Di Zhao ◽  
Yibo Pan
Keyword(s):  
Shear Strength ◽  
Thermal Cycling ◽  
Solder Joints ◽  
High Reliability ◽  
Sharp Decrease ◽  
Thermal Shock Test ◽  
Shear Properties ◽  
Equivalent Time ◽  
Ultrasonic Assisted ◽  
Reliability Of Solder Joints

AbstractThrough ultrasonic wave assisted Sn2.5Ag0.7Cu0.1RExNi/Cu (x = 0, 0.05, 0.1) soldering test and − 40 to 125 °C thermal shock test, the microstructure and shear properties of Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints under thermal cycling were studied by the SEM, EDS and XRD. The results show that the Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints with high quality and high reliability can be obtained by ultrasonic assistance. When the ultrasonic vibration power is 88 W, the ultrasonic-assisted Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu solder joints exhibits the optimized performance. During the thermal cycling process, the shear strength of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints had a linear relationship with the thickness of interfacial intermetallic compound (IMC). Under the thermal cycling, the interfacial IMC layer of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints consisted of (Cu,Ni)6Sn5 and Cu3Sn. The thickness of interfacial IMC of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints was linearly related to the square root of equivalent time. The growth of interfacial IMC of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints had an incubation period, and the growth of IMC was slow within 300 cycles. And after 300 cycles, the IMC grew rapidly, the granular IMC began to merge, and the thickness and roughness of IMC increased obviously, which led to a sharp decrease in the shear strength of the solder joints. The 0.05 wt% Ni could inhibit the excessive growth of IMC, improve the shear strength of solder joints and improve the reliability of solder joints. The fracture mechanism of ultrasonic-assisted Sn2.5Ag0.7Cu0.1RExNi/Cu solder joints changed from the ductile–brittle mixed fracture in the solder/IMC transition zone to the brittle fracture in the interfacial IMC.

Evolution of Fault Self-Repairing Circuit with High Reliability

2013 ◽  
Vol 462-463 ◽  
pp. 654-657
Author(s):  
Jian An Lou ◽  
Yang Li ◽  
Jian Hua Yu
Keyword(s):  
Evolutionary Algorithm ◽  
System Design ◽  
Continuous Improvement ◽  
High Reliability ◽  
Structure And Function ◽  
Digital System ◽  
Electronic Systems ◽  
Electromagnetic Environment ◽  
Digital System Design ◽  
And Function

With the continuous improvement of the complexity of the microelectronic system, its reliability risk is becoming more and more obvious. In order to improve the reliability of electronic systems in complex electromagnetic environment, this paper proposes a new fault self-repairing method; the idea is to realize controllable silicon evolution on the FPGA. A MicroBlaze CPU and VRC array are designed, and the CPU runs the evolutionary algorithm to configure the VRC array, dynamically changing the structure and function of the circuit, so as to obtain high reliability of the digital fault self-repairing circuit. Evolving fault self-repairing technology provides a new way for the high reliability of the digital system design.

scholarly journals Detectability of Delamination in Concrete Structure Using Active Infrared Thermography in Terms of Signal-to-Noise Ratio

2018 ◽  
Vol 8 (10) ◽  
pp. 1986 ◽  
Author(s):  
Jungwon Huh ◽  
Van Mac ◽  
Quang Tran ◽  
Ki-Yeol Lee ◽  
Jong-In Lee ◽  
...  
Keyword(s):  
Concrete Structure ◽  
Signal To Noise Ratio ◽  
High Reliability ◽  
Heating Time ◽  
Observation Time ◽  
Percentage Error ◽  
Heating Regime ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Whole Life Cycle

Detecting subsurface delamination is a difficult and vital task to maintain the durability and serviceability of concrete structure for its whole life cycle. The aim of this work was to obtain better knowledge of the effect of depth, heating time, and rebar on the detectability capacity of delamination. Experimental tests were carried out on a concrete specimen in the laboratory using Long Pulsed Thermography (LPT). Six halogen lamps and a long wavelength infrared camera with a focal plane array of 640 × 480 pixels were used as the heat source and infrared detector, respectively. The study focused on the embedded imitation delaminations with the size of 10 cm × 10 cm × 1 cm, located at depths varying from 1 to 8 cm. The signal-to-noise ratio (SNR) was applied as a criterion to assess the detectability of delamination. The results of this study indicate that as the provided heating time climbed, the SNR increased, and the defect could be identified more clearly. On the other hand, when using the same heating regime, a shallow delamination displayed a higher SNR than a deeper one. The moderate fall of the SNR in the case of imitating defect located below reinforced steel was also observed. The absolute contrast was monitored to determine the observation time, and the nondimensional prefactor k was empirically proposed to predict the depth of delamination. The mean absolute percentage error (MAPE) was used to quantitatively evaluate the difference between forecasted and real depth, which evaluation confirmed the high reliability of the estimated value of the prefactor k.

A Study of Delamination Mechanism of Thermal Barrier Coating under Thermal Cycling and Aging Condition by Residual Stress History

2009 ◽  
Vol 417-418 ◽  
pp. 173-176
Author(s):  
Hiroyuki Waki ◽  
Akira Kobayashi
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Thermal Cycling ◽  
Thermal Aging ◽  
Ceramic Coating ◽  
Plane Surface ◽  
Diffraction Method ◽  
Thermal Barrier ◽  
Stress History ◽  
Bond Coating

Thermal barrier coatings (TBCs) have been employed for the insulation of substrates from high temperature in gas turbine plants. The TBC system consists of ceramic top coating, metallic bond coating and substrate. Delamination of the ceramic coating is important problem in TBC systems. In this paper, the delamination mechanism was studied by residual stress history under thermal aging and thermal cycle conditions. In-plane residual stress histories of ceramic coating and bond coating after thermal aging and cycling were measured by X-ray diffraction method. The residual stress under thermal cycling was also calculated by FEM analysis. The results obtained were as follows: (1) in-plane surface residual stresses of the coatings scarcely changed regardless of the increase of thermally grown oxidation (TGO). (2) high compressive thermal stress, residual stress at room temperature, in ceramic coating induced by thermal stress did not occur. It was found that stress of ceramic top coating was relaxed by micro cracks and driving stress of delamination was in-plane high compressive stress.

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