Intricacies in the Failure Analysis of Integrated CapacitorsMahinay, Christopher S.; Reyes, Christian; Calanog, Ricardo; Mendaros, Raymond
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02039-w
Integrated capacitors such as in metal–insulator–metal and metal–oxide-metal capacitors use metal as top and bottom plates while the metal–oxide–semiconductor capacitors utilize polysilicon layer as top plate and silicon substrate as bottom plate (Utmel Electronics, 2021, What is the Difference between MOM, MIM and MOS Capacitors?. https://www.utmel.com/blog/categories/capacitors/). There are three (3) major challenges and solutions were discussed in this technical paper. First is the failure site localization of a subtle defect in the capacitor plates. To determine the specific location of the defect site, electron beam-induced current (EBIC) analysis was performed while the part was biased using a nanoprobe setup under scanning electron microscopy (SEM) environment. Second is the failure mechanism that resulted to contentions between an electrically induced physical damage (EIPD) or a fabrication process defects, particularly for damage sites that are not at the edge of the capacitor and without obvious manifestations of fabrication process anomalies such as bulging, voids, unetched material or shifts in the planarity of the die layers. To further understand the defect site, scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy were utilized to obtain high magnification imaging and elemental area mapping. Third is the misled conclusion to be an EIPD site manifested by burnt and reflowed metallization. The EIPD site was only a secondary effect of a capacitor dielectric breakdown. This refers to the root cause (capacitor dielectric breakdown) that was successfully uncovered after the thorough review on the die circuit schematic, inspection of the capacitors connected to the EIPD sites, review of the fault isolation results and pursuing the further physical failure analysis. As a result of the failure analysis, customer and Analog Devices Incorporated manufacturing hold lots were accurately dispositioned and related corrective actions were precisely identified and implemented.
A Comprehensive Failure Analysis Approach Utilizing High-Resolution Targeted Patterns (HRTP) for ATPG Diagnosis Resolution Improvement, Test Coverage Resolution, and Further Fault LocalizationEstores, R.; Barbian, E.; Boukhanfra, L.; Villareal, K.; Sabate, A.
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02018-1
This paper discusses a comprehensive failure analysis approach to digital failures. High-resolution targeted patterns (HRTP) are highlighted along with their advantages in failure analysis by aiding in automated test pattern generation (ATPG) diagnoses resolution improvement, increasing the chance of detecting fault not detected by patterns implemented on automated test equipment (ATE), determine a potential test screen, provide stimulus for further fault localization, and increase the analysis success rate. This comprehensive approach and the use of HRTP have proven very helpful in the analysis of internal requests and customer returns. Three cases will be discussed in this paper to highlight these advantages.
Failure Analysis of 35NCD16 Steel M12x1.25 Nut in Aerospace Component Structural Qualification Testing: A Metallurgical PerspectiveJalaja, K.; Manwatkar, Sushant K.; Gupta, Rohit Kumar
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02035-0
During the structural qualification testing of propellant tanks of a liquid engine, one M12 nut made of 35NCD16 steel used for the testing was found broken. Structural qualification testing was conducted to verify the design adequacy of tanks in human-rated missions. A detailed metallurgical investigation was conducted on the failed nut, bolt, and washers to determine the underlying cause of fracture. This investigation included detailed visual inspections, hardness testing, as well as microstructural characterization using tools such as the optical and scanning electron microscopy. In a comparative study, the nuts adjacent to and diametrically opposite from the failed assembly were examined along with exemplar nuts. Fractographic analysis revealed dimpled rupture characteristics with substantial inclusions in the longitudinal direction of the nut. A detailed investigation of the failed nut revealed long, aligned non-metallic inclusions, primarily mixed oxides of Mn, Si, and Cr. These inclusions were found to be the underlying cause of nut fracture below maximum tensile stresses.
Detection and Localization of Undesired Quasi-Static Transitions in a Scan Flip-FlopMerassi, Angelo Antonio
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02029-y
Quasi-static transition failures in the main logic of modern semiconductors devices are very challenging to be detected in a standard test production environment, because they need a lot of test time to be activated, and usually this is not compatible with a reasonable test time. Many semiconductor manufacturers usually agree not to test these process marginalities to avoid increasing the total cost of the device so much, but accept a few ppm of returns from the customer. In general we are talking about a few decimals of ppm. The typical cases that we can encounter are retention failures in flip-flops, unexpected set, or reset happening after tens of milliseconds. The aim of this work is to discuss the technique/method to deal with quasi-static transition failures. The paper also proposes one possible strategy to detect and locate them in a failure analysis test environment making a benchmark between the most appropriate fault localization technique.
Unraveling the Strength Secrets: How Polypropylene Fiber-Reinforced Asphalt Mixtures Defy FractureAkram, Hesham; Hozayen, Hozayen A.; Abdellah, Mohammed Y.; Khodary, Farag
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02020-7
The semi-circular bending (SCB) and Indirect Tensile Asphalt Cracking Test (IDEAL-CT) are considered primary techniques recommended for assessing the fracture characteristics of asphalt mixtures under intermediate temperature conditions. The way specimens are prepared represents a fundamental distinction between the two testing techniques. SCB test is somewhat intricate and significantly limited by the specimen preparation steps, which include cutting and notching; the evolved IDEAL-CT test, in contrast, does not necessitate elaborate cutting and notching procedures. In this paper, the correlation between various fracture parameters measured from SCB and IDEAL-CT tests for asphalt mixtures reinforced with different dosages of polypropylene fibers was evaluated. The study included a comparison of the parameters of crack resistance and stiffness indexes based on specimen preparation, variability, and the effect of polypropylene fiber doses. The flexibility index and cracking resistance index showed a high linear correlation (R2 = 0.86) and (R2 = 0.84), respectively. The results of notched specimens in the SCB test exhibited greater variability in all fracture parameters results compared to the results of the IDEAL-CT test. The simplicity of preparing specimens primarily supports the IDEAL-CT test as a laboratory method for assessing the fracture characteristics of asphalt mixtures. The inclusion of varying amounts of polypropylene fibers has proven to significantly influence the values of fracture parameters in the asphalt mixture.
Towards the Automation of Non-destructive Fault Recognition: Enhancement of Robustness and Accuracy Through AI Powered Acoustic and Thermal Signal Analysis in Time, Frequency- and Time-Frequency DomainsBrand, Sebastian; Altmann, Frank; Grosse, Christian; Kögel, Michael; Hollerith, Christian; Gounet, Pascal
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02030-5
Non-destructive inspection and analysis techniques are crucial for quality assessment and defect analysis in various industries. They enable for screening and monitoring of parts and products without alteration or impact, facilitating the exploration of material interactions and defect formation. With increasing complexity in microelectronic technologies, high reliability, robustness and thus, successful failure analysis is essential. Machine learning (ML) approaches have been developed and evaluated for the analysis of acoustic echo signals and time-resolved thermal responses for assessing their ability for defect detection. In the present paper different ML architectures were evaluated, including 1D and 2D convolutional neural networks (CNNs) after transforming time domain data into the spectral- and wavelet domains. Results showed that 2D CNNs processing data in wavelet domain representation performed best, however at the expense of additional computational effort. Furthermore, ML-based analysis was explored for lock-in thermography to detect and locate defects in the axial dimension based on thermal emissions. While promising, further research is needed to fully realize its potential.
Folding Failure and Improvement of Sun Shield of Toxic Goods Wagon Based on Simulation and TestHe, Maosheng; Li, Zhigang; Zhou, Xiaokun; Fu, Tingting; Hou, Yu
2024 Journal of Failure Analysis and Prevention
doi: 10.1007/s11668-024-02013-6
The paper describes the structure and failure of toxic goods wagon. Furthermore, the connection and corrosion of the wagon sun shield were investigated on site. According to the field analysis, the aerodynamic model of a group of five vehicles was established, and the stress of the sun shield under the aerodynamic load was analyzed. The finite element model was built and the static simulation analysis of four kinds of working cases was carried out. Two kinds of sun shield specimens with different thickness were manufactured, and the wagon was tested under the normal bolt condition and missed bolts condition. Based on the above research, the paper proposes the optimized scheme. Finally, the connection scheme of the sun shield is modified. The modified sun shield works well in service.