Development of a Non-Invasive On-Chip Interconnect Health Sensing Method Based on Bit Error Rates

Electronic products and systems are widely used in industrial network systems, control devices, and data acquisition devices across many industry sectors. Failures of such electronic systems might lead to unexpected downtime, loss of productivity, additional work for repairs, and delay in product and service development. Thus, developing an appropriate sensing technique is necessary, because it is the first step in system fault diagnosis and prognosis. Many sensing techniques often require external and additional sensing devices, which might disturb system operation and consequently increase operating costs. In this study, we present an on-chip health sensing method for non-destructive and non-invasive interconnect degradation detection. Bit error rate (BER), which represents data integrity during digital signal transmission, was selected to sense interconnect health without connecting external sensing devices. To verify the health sensing performance, corrosion tests were conducted with in situ monitoring of the BER and direct current (DC) resistance. The eye size, extracted from the BER measurement, showed the highest separation between the intact and failed interconnect, as well as a gradual transition, compared with abrupt changes in the DC resistance, during interconnect degradation. These experimental results demonstrate the potential of the proposed sensing method for on-chip interconnect health monitoring applications without disturbing system operation

??????????????? ????????? ????????? ?????? ?????? ?????????????????? ?????? ??????

Qualification includes all activities to demonstrate that a product meets and exceeds the reliability goals. Manufacturers need to spend time and resources for the qualification processes under the pressure of reducing time to market, as well as offering a competitive price. Failure to qualify a product could result in economic loss such as warranty and recall claims and the manufacturer could lose the reputation in the market. In order to provide valid and reliable qualification results, manufacturers are required to make extra effort based on the operational and environmental characteristics of the product. This paper discusses optimal interval censoring design for reliability prediction of electronic packages under limited time and resources. This design should provide more accurate assessment of package capability and thus deliver better reliability prediction.close

Reliability Assessment of Low-Power Processors in Supercomputing Systems

Low-power processors have emerged as an alternative for supercomputers and cloud computers to reduce their energy consumption. Many low-power processors are designed and used for mobile devices, such as phones, tablets, and laptops, and their reliability is commonly evaluated based on mobile use conditions. Supercomputers are, on the other hand, often used for high-performance computing, including complex calculations, graphics processing, and large-scale modeling and simulations, which generates heavy workload and stress conditions. Therefore, the reliability of low-power processors in supercomputing systems can be of concern. This paper assessed the lifetime of low-power processors used in high-performance computing environments. Failure modes, mechanisms, and effects analysis identified thermo-mechanical fatigue at board level solder joints as a critical failure mechanism of low-power processors. An HPC use condition was estimated based on the supercomputer use statistics collected from a supercomputing center. Experimental studies were conducted to correlate the use conditions with changes in the package temperature. A physics-of-failure-based reliability model was used to estimate the lifetime of low-power processors under multiple load ratios with or without active cooling. Recommendations for reliable operation of low-power processor-based supercomputers were presented

Lifetime Prediction of Optocouplers in Digital Input and Output Modules based on Bayesian Tracking Approaches

Digital input and output modules are widely used to connect digital sensors and actuators to automation systems. Digital I/O modules provide flexible connectivity extension to numerous sensors and actuators and protect systems from high voltages and currents by isolation. Components in digital I/O modules are inevitably affected by operating and environmental conditions, such as high voltage, high current, high temperature, and temperature cycling. Because digital I/O modules transfer signals or isolate the systems from unexpected voltage and current transients, their failures may result in signal transmission failures and damages to sensitive circuitry leading to system malfunction and system shutdown. In this study, the lifetime of optocouplers, one of the critical components in digital I/O modules, was predicted using Bayesian tracking approaches. Accelerated degradation tests were conducted for collecting the critical performance parameter of optocouplers, current transfer ratio (CTR), during their lifetime. Bayesian tracking approaches, including extended Kalman filter and particle filter, were applied to predict the failure. The performance of each prognostic algorithm was then compared using accuracy and robustness-based performance metrics

A Prognostic Method of Assessing Solder Joint Reliability Based on Digital Signal Characterization

Electronics are subjected to thermal, mechanical or chemical stress conditions during their operations. These stress conditions accumulate damages to the electronic system, adversely affecting its components and interconnects including solder joints. Solder joint degradation can cause system malfunctioning, which eventually results in catastrophic failures. In order to prevent system failures, it is required to manage the system health continuously by monitoring damages such as solder joint degradation. Regardless of stress conditions, solder joints often start to degrade from their surface where high speed signals in an electric circuit are concentrated due to the phenomenon referred to as the skin effect. Thus, high speed signals such as digital signals can serve as a sensitive means of detecting solder joint degradation at early stages. This paper presents a diagnosing method of assessing solder joint reliability based on digital signal characterization. Accelerated life tests are conducted to generate solder joint failure. The test setup consists of a circuit board with solder joints, a digital signal transceiver, an environmental test chamber and a stress application fixture. Constant mechanical shear stress is applied to the solder joints of a circuit board at an elevated temperature. A digital signal transceiver generates high speed signals travelling through the solder joints, and continuously monitors the signal characteristics which indicate signal integrity. The test results confirm that the signal characteristics show statistically significant variations between intact and cracked state of the solder joint, and the parameter variations indicate the deterioration of the signal integrity. These results suggest that digital communication signals can be used as a non-destructive diagnostic tool of physical degradation. It can be improved as a tool which provides early warning of impending system failures without installing additional fault sensing instrumen- s. This diagnostic approach may serve as a proactive prognostic module that allows for real-time health management of electronic products and systems

Ni-stabilizing additives for completion of Ni-rich layered cathode systems in lithium-ion batteries: An Ab initio study

We propose the development of Ni-stabilizing electrolyte additives to fundamentally prevent the degradation of Ni-rich layered cathode systems in lithium-ion batteries because unstable surface Ni and the dissolved Ni2+ are the major problems of those systems. The Ni2+-affinity is investigated as a key factor of the Ni-stabilizing additives. However, when providing a noble function to the electrolyte additive, the redox stability of the additives should be also understood. Thus, in addition to the intrinsic oxidation energy, the protonation and dehydrogenation energies of the additive molecules are calculated to determine the H-transfer-driven electrolyte oxidation. The Li+-complexation is considered to model the electrolyte reduction. We investigate the molecular-leveled computed factors of electrolyte materials using fully automated high-throughput ab initio calculations. Those computed factors for representative molecules based on CO3, SO4, SO3, SO2, PC3, PO3, and OPO3, which are of great interest as major parts of electrolyte materials, are discussed to guide the additive development. In particular, SO2 and OPO3 molecules, which can strongly stabilize Ni2+ in a structurally stable form, have great advantages as Ni-stabilizing electrolyte additives for completion of Ni-rich layered cathode systems