Optimization of TSV Leakage in Via-Middle TSV Process for Wafer-Level Packaging

Through silicon via (TSV) offers a promising solution for the vertical connection of chip I/O, which enables smaller and thinner package sizes and cost-effective products by using wafer-level packaging instead of a chip-level process. However, TSV leakage has become a critical concern in the BEOL process. In this paper, a Cu-fulfilled via-middle TSV with 100 µm depth embedded in 0.18 µm CMOS process for sensor application is presented, focusing on the analysis and optimization of TSV leakage. By using etch process, substrate defect, and thermal processing co-optimization, TSV leakage failure can be successfully avoided, which can be very instructive for the improvement in TSV wafer-level package yield as well as device performance in advanced semiconductor technology.

A METHOD TO REDUCE THE NUMBER OF ASSEMBLY TIGHTENING PASSES IN BOLTED FLANGE JOINTS

Bolted flange joints are extensively used in the pressure vessels and piping equipment and rotating machinery. Achieving a uniform bolt preload during the assembly process is particularly important to satisfy in bolted flange connection of oil and gas and fossil and nuclear applications. However, it is a very difficult task when tightening all bolts one by one due to elastic interaction. The risk of leakage failure under service loading is consequently increased because of the scatter of the bolt preload. This paper takes the advantage of a developed analytical model based on the theory of circular beams on linear elastic foundation that simulate the elastic interaction of bolted flange joints to reduce the number of passes while achieving bolt load uniformity. As such, a novel methodology for the optimization of the tightening sequence strategies is suggested to obtain uniform bolt tension while avoiding yield under minimum tightening passes. In this regards, based on the target preload, the load applied to each bolt in each pass is suggested. The developed approach is validated both numerically using FEM (finite element method) and experimentally on a NPS 4 class 900 welding neck flange joint using the criss-cross tightening and sequential patterns.

Water Network-Failure Data Assessment

The water-supply system is one of the basic and most important critical infrastructures. Water supply service disruption (water quality or quantity) may have serious consequences in modern societies. Water supply service is subject to various failure modes. Failure modes are specified by their degradation mechanisms, criticality, occurrence frequency and intensity. These failure modes have a random nature that impacts on the network disruption indicators, such as disruption frequency, network downtime, network repair time and network back-to-service time, i.e., the network resilience. This paper focuses on the water leakage failure mode. The water leakage failure mode assessment considers the unavoidable annual real water losses and the infrastructure leakage index recommended by the International Water Association’s Water Loss Task Force specialist group. Probabilistic statistical modelling was implemented to assess the seasonal index, the failure rates and the expectation value of the “mean time between failures.” The assessment is based on real operational data of the network. Specific attention is paid to the sensitivity of failures to seasonal variations. The presented methodology of the analysis of the water leakage failure mode is extendable to other failure modes and can help in developing new strategies in the management of the water-supply system in normal operation and crisis situations.

Application of Variable Distance Photoelectric Sensor in Precision Automatic Sowing and Fertilization

In order to realize the real-time monitoring of precision automatic seeding and fertilization, a monitoring system of precision automatic seeding and fertilization integrated machine based on variable distance photoelectric sensor is designed. In this system, STM32F103R8T6 single chip microcomputer hardware system is used as the lower computer to judge the running state of the machine. Through Modbus protocol, the received information is transmitted to the upper computer interface of MCGSTPC touch screen for real-time display. In the laboratory test, the designed seed metering device and fertilizer applicator can meet the requirements of wide precision sowing and wide uniform fertilization. All indicators can meet the requirements. In the field experiment, the phenomenon of seed leakage (fertilizer leakage) failure and response delay will occasionally appear. Moreover, the alarm accuracy of the monitoring system is more than 95%, and the response time of fertilizer missing, blocking and leakage is short. Therefore, the system designed in this study can realize the real-time and high-precision monitoring of precision automatic seeder, which is helpful to improve the quality of precision seeder.

Leakage Failure Analysis of the ERW Steel Pipeline

This paper provides a thorough investigation on the leakage reason of the ERW steel pipeline in an oil field. Through appearance inspection, physicochemical inspection, metallographic inspection and scanning electron microscope (SEM), it was found that the main reason of corrosions was caused by residual liquid at the bottom of the pipeline and O2 and CO2 in the air pressure test. The corrosion medium was large volume of O2 and CO2 forming continuously saturated corrosive aqueous solution in small volume of residual liquid, and the corrosion type was the under-deposit corrosion. It is recommended to conduct hot air purging on the pipelined before pressure test for building pipelines in the future, and if the pipeline is not put into use in time, it is recommended to use nitrogen to maintain pressure.

Leakage Failure Analysis of 80SS Tubing in Gas Field

During acidizing process in a gas field, leakage of 80SS anti-sulfur tubing occurred.The main reasons for failure of the tubing have been investigated based on analysis techniques of chemical composition analysis,Optical Microscopy (OM), Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) , X-ray Diffraction (XRD) and mechanical test. The results show that composition and mechanical properties of the tubing were all in accordance with the corresponding requirements of API Spec 5CT standards. Furthermore,leakage of tubing from inner wall was caused by combined impacts of acid corrosion, H2S corrosion, low PH value, high temperature and a certain pressure. Meanwhile, Low concentration of corrosion inhibitor was also one of the factors of corrosion perforation.