Using High Speed Camera for Electronic Board Failure Analysis

Modern large frame F, G, & J class gas turbine flow path component design requires the complex integration of multiple design disciplines that traditionally reside with distinct specialists. A traditional design system for an actively cooled gas turbine blade includes aerodynamicists, heat transfer engineers, structural engineers and a failure or lifetime prediction engineers passing information through a manual process with a small number of iterations between the disciplines. Design or manufacturing engineers can also be involved ensuring manufacturability and policing best practices in a predominantly deterministic design system. Over the past few decades robust design or probabilistic design philosophies along with cluster computing advancements have accelerated the release of commercial software that allows for the automation of multiple analytical evaluations at off design points. These software codes allow for process automation of several independent codes executed multiple times at various conditions for automated design of experiment (DOE), and reliability analysis using Monte Carlo or other advanced approximate probabilistic methods across the entire design system. In this paper, the authors are presenting a novel approach of using a commercially available process integration tool to fully integrate a series of other commercially available tools for a root cause failure analysis of a F class turbine blade rather than a new make design. The analysis incorporated a computational fluid dynamics model (CFD) to define inlet temperatures and pressure profiles, a fully conjugate thermal analysis interacting with a finite element (FEA) solver linked to a proprietary creep lifetime prediction model. A DOE was executed to define the meaningful parameters and help rule out potential causes of failure such as loss of coating or compromised cooling system as a contributing factor of the failure which greatly reduced the amount of time and money needed for the investigation. A probabilistic failure analysis was then executed and surrogate models created for quick probabilistic assessment for different operating conditions. This allowed for validation against fleet history to explain the single engine failure not previously observed. Setting up the non-deterministic models initially allowed for rapid redesign in less than 1 month time with confidence that the true root cause was identified and mitigated. It further allowed for feedback and calibrations to the traditional design system methodology.

The paper reports the investigation on the root cause of source-drain leakage in bulk FinFET devices. While the failing device was readily isolated by nanoprobing technique and the electrical analysis pinpointed the potential defect location inside the Fin channel, the identification of physical root cause went through extreme challenges imposed by the tiny-sized device and the unique FinFET 3D architecture. The initial TEM analysis was misled by the projection of a species in the lamella surface and thus could not explain the electrical data. Careful analysis on the device structure was able to identify the origin of the species and led to the discovery of the actual root cause. This paper will provide the analysis details leading to the findings, and highlight the role of electrical understanding in not only providing guidance for physical analysis but also revealing the true root cause of failure in FinFET devices.

Iron sulfide scale is found almost ubiquitously in maturing oilfield produced water handling and injection systems. Keeping injection systems clean of sulfide scale is becoming more of a shared challenge, but there are few examples where true root cause analysis has led to specific laboratory testing and development of bespoke removal and prevention methods. This paper aims to link these aspects by sharing the best practices from around the world with cutting edge techniques and chemistries used to maintain flow assurance and injectivity in produced water handling systems affected by iron sulfide scale. Discussion includes root causes analysis of iron sulfide scale formation and deposition mechanisms focusing on the interplay of pH, along with sources of iron and sulfide. The paper goes onto discuss laboratory and field evaluation of control methods. Finally, the root causes of iron sulfide scale formation and deposition mechanism, including the relative advantages and merits of the different techniques, including: Chelating agents (for iron sequestration) Surfactants (for water wetting) Biocide (to target SRB and biofilm) Corrosion inhibitor (to lower iron in system) Sulfide scale inhibitors (threshold inhibition of scale) Additionally, case histories are used to elaborate the theoretical discussion. The first case history is from an offshore oilfield water injection system, where fouling occurred due to changes in the flow assurance strategy further upstream and capture the lessons learned on the interplay of different production chemicals. The second case history concerns an onshore oilfield with a vast water injection system of over 3,000 wells supporting approximately 5,000 production wells. The paper concludes with a summary of the decades of experience of solving the most challenging sulfide scaling scenarios, as well as cutting-edge research on a new class of polymeric exotic sulfide scale inhibitor dispersant, effective as threshold concentrations against even lead and zinc sulfide.

Aggregated results from twenty years of community-engaged assiduous restoration of severely degraded coastal littoral systems in New Zealand (NZ) reveal numerous fundamental and substantive natural improvements to dune form, function, and storm resilience. This is accomplished by simple, low-cost exclusive utilisation of the variably threatened local indigenous dune plant species. These valuable and innovative enhancements succeed countless decades of cascading consequences from numerous impacts instigated by historic (and frequently continuing) damaging effects on those previously natural coastal dune ecosystems – impacts that subsequently induced problematic littoral retreat – the true root cause of prevailing coastal erosion. The durable reversals were often generated in less than two decades, contemporaneously with adverse storm surge and sea level rise conditions. Research reveals many global dune ecosystems are afflicted with analogous normalised degradation and erosion difficulties, with the earliest active circumvention recorded in sixteenth century Denmark (McKelvey 1999). Historic plus current pressures such as coastal settlement impacts and continuing agricultural use of dunelands similarly threaten numerous global littoral margins, alongside recent concerns regarding the compounding effects of climate change. Successful, affordable, diligent dune restoration work pioneered in NZ has extensive benefits for other nations experiencing similarly challenging attrition on degraded coastal zones. Persuasive data is presented to validate the numerous persistently accrued benefits of this cost-effective and enduring coastal adaptation response.

Chapter 15 - Failure-Mode Analysis

This paper describes a new LIT technique named External trigger Synchronous LIT (ESLIT). LIT is widely used in device analysis from initial investigation to fault isolation. This technique uses a “lock-in function” to reduce thermal spreading from the heat source. Conventional LIT analysis is usually performed under limited set-up conditions with some probes without ATE. However, in the case of ESLIT, ATE can be used to reproduce the failure state of the DUT during the LIT analysis. And the “lock-in function” is used to identify specific hotspots that correspond to IDDQ failure states. In our experiment, the results of ESLIT perfectly agreed with IDDQ fault diagnosis candidates. On the other hand, PEM and OBIRCH detected not only logic-related points, but also non-logic-related points that did not match the fault diagnostic results. We also confirmed that ESLIT is available nondestructively. We think that ESLIT is a useful technique for IDDQ failure analysis since it can identify the true root cause even in the case of multiple failure.

28 - Inverters

A new evolution in graph modeling for conflict resolution (GMCR), a robust methodology for conflict resolution, is presented in this research to incorporate the systems thinking concept into the conventional paradigm of GMCR so that the dynamic nature of water–environmental conflicts can be modeled, and better outcomes obtained. To achieve this objective, a methodology is developed in three phases: static, dynamic, and outcome-based analyses. To develop the methodology, the Tigris–Euphrates basin conflict in the Middle East over the past 30 years, as a real-life case study, is used to show the robustness and capabilities of the proposed approach. Finally, a sustainable resolution to the current conflict is proposed, and the results are discussed. The proposed methodology benefits from improving the existing and often static-based conflict resolution developments by considering the dynamic nature so that the true root causes of complex conflicts are addressed, better strategic insights achieved, and comprehensive resolution provided.

Failure analysis plays an important role in yield improvement during semiconductor process development and device manufacturing. It includes two main steps. The first step is to find the defect and the second step is to identify the root cause. In the past, failure analysis mainly focused on the first step, namely how to find the defect for a failure; because in the previous generations of technology, once the defect was found, its root cause was relatively easy to be understood. As the current advanced semiconductor technology has become tremendously complicated, especially 3D devices, like FinFET, a defect found by failure analysis can be substantially transformed from its original defect by subsequent processes and can be totally different from its origin in size and shape. Thus, sometimes, the second step, identifying the root cause for a defect becomes more challenging and takes more time than the first step. With combination of failure analysis and inline inspection, it enables us to establish the relationship between the failure analysis defect and an in-line defect. This can link the defect for a device functional failure to its source layer and process step more quickly, leading to fast root cause identification. In this paper, the methodology was validated by fast identification of the root causes for three case studies in the latest FinFET technology.

This paper discusses the performance analysis effort being carried out in the NASA Deep Space Network. The activity involves root cause analysis of failures and assessment of key performance metrics. The root cause analysis helps pinpoint the true cause of observed problems so that proper correction can be effected. The assessment currently focuses on three aspects: (1) data delivery metrics such as Quantity, Quality, Continuity, and Latency; (2) link-performance metrics such as antenna pointing, system noise temperature, Doppler noise, frequency and time synchronization, wide-area-network loading, link-configuration setup time; and (3) reliability, maintainability, availability metrics. The analysis establishes whether the current system is meeting its specifications and if so, how much margin is available. The findings help identify the weak points in the system and direct attention of programmatic investment for performance improvement.

Defect isolation and failure analysis is a key factor that drive development and manufacturing yield improvements in semiconductor packaging industry. From a manufacturing point of view, ensuring adequate package reliability is becoming more challenging due to increasing packaging complexity and a more pronounced impact from material physical property mismatch among packaging materials and components. The task of isolating defects and finding root cause is further complicated by ever shrinking feature sizes within the device and/or package, already approaching the nanometer range in contemporary semiconductor packages. Conventional failure analysis techniques such as physical cross sectioning or micro-cutting using focused ion beams(FIB) are sometimes no longer sufficient to find these defects. Both physical cross section and FIB are only capable of exposing the defect in two dimensions (x and y directions), which makes pinpointing the defect in depth, i.e., the z direction, extremely difficult when dealing defects with micron and submicron size. Additional complications are many times introduced during conventional sample preparation, which can introduce undesirable artifacts associated with the module and/or device depackaging. These artifacts may mask the true defects, or lead to misinterpretation of the true cause of failure. In this work, it has been determined that a three-dimensional failure analysis method is critical for finding some defects in silicon packages. For example, xenon difluoride (XeF2) has excellent selectivity to silicon and provides efficient material removal by chemical reaction, generating gaseous by-products that can be readily exhausted [1]. Furthermore, XeF2 has very little reaction with non-silicon materials, such as SiO2, and the metals and polymers commonly used in semiconductor devices and packages. This paper reports the application of XeF2 as an effective failure analysis technique to reveal defects in silicon packages. The mechanism of selective reaction between XeF2 and Si is discussed and key design features of the failure analysis tool are presented. The paper also highlights a few case studies which advantageously utilize XeF2 etching to expose defects. XeF2 was especially effective in detecting the source of electrical leakage in 3D packages having Through Silicon Via (TSV) structures. Due to its high etching selectivity to silicon, the leakage area in electrically failing samples was found to be due to damage of the TSV liner (passivation layer material) and further analysis reveals a three dimensional view of the TSV defect. With the addition of XeF2 etching, further characterization of defects by traditional methods such as FIB micro cutting also becomes more practical. The work suggests that a wider application of Si removal via XeF2 can be achieved by combining mechanical milling of bulk silicon followed by a final, low stress, silicon removal by XeF2 etching.

A high volume, high speed manufacturer experienced component defects at a rate of 1 in every 30 boards. Failure signature was CDM–like. Root cause evaluation was undertaken to find the culprit/s and implement corrective actions. Details of the problem, investigation and corrective action are discussed in this paper.

The focused ion beam system has been widely used as a critical failure analysis tool as microprocessor technology advances at a ramping speed. It has become an essential step in failure analysis to reveal physical defects after electrical fault isolation. In the highly competitive and challenging environment prevalent at present, failure analysis throughput time is of utmost important. Therefore, a quick, efficient and reliable physical failure analysis technique is needed. This paper discusses the applications of FIB as a defect localization and root cause determination tool through the passive charge contrast technique and pattern FIB analysis.

The electronic components are the core of all electronic products, the reliability and maintainability directly affect manufacture products quality. And as products become more complex and more demanding. We need more reliable components. In order to solve this problem, we need to analysis how and why those components failed. Failure analysis cases are important data for analysis, data mining and improving reliability. China Electronic Product Reliability and Environment Testing Research Institute (CEPREI) is the earliest research organization engaged in reliability research and failure analysis in China, and has accumulated rich failure case data. By combining data mining methods such as Bayesian network, correlation analysis, we can perform statistical analysis and root cause analysis to assist failure analysis and improve product reliability. This paper will apply the failure analysis case of the electromagnetic relay, and explores and analyses related regular pattern.

Fractography of Metals and Plastics