Six Sigma in Semiconductor: Continuous Improvement in Production Floor Area

This study addresses the improvement of first pass yield on the production floor of ABC Semiconductor. ABC is a company running a multiple volume complex product in aligning with memory business in the operation. First pass yield refers to the proportion of fully built product that pass testing without the need for additional rework. The first pass yield (FPY) project showed steady progression for its first five years. But over the following one year, the primary yield metric which is first pass yield has stayed stagnant. The goal of the paper presented here is to analyze the reasons for the current performance and propose novel ways of improving the metric again using quality management tools. The most common is using 7QC tools method by categorizing failure pareto that will lead to targeted corrective action to reduce the recurrence of pre-identified failure modes. A DMAIC methodology is establish on how to define an efficient corrective action, along with a top three major defect on data acquired from ABC organization. From the exercise, the yield loss was able to be reduced from 17.4% to 3.52%.

Minimum Settings Calibration Method for Low-Cost Tri-Axial IMU and Magnetometer

This manuscript presents a minimum settings calibration method for low-cost tri-axial inertial measurement units (IMU) and magnetometers. At first, we analyze the major defect of the traditional calibration methods for tri-axial accelerometers and magnetometers. To fix that problem, we just utilize the ellipsoid model to calibrate the tri-axial accelerometer and magnetometer preliminarily, then complete the calibration work with at least two reference angular positions, and prove that two reference angular positions are minimum requirements in the calibration progress. Next, the tri-axial gyroscope is calibrated based on the nonlinear cost function with the aid of the pre-calibrated accelerometer. The simulation and real-world experiment results show that the proposed method is practical and effective, suggesting that this technique is a viable candidate for the IMU and magnetometer applications.

Fractographic Analysis of GTAW Robotic Welded Joints Fractured under Stress in Experimental HSLA Cr-Ni Steel

The welding current (A), arc voltage (V) preheating (°C), travel speed (mm·min-1) and net heat input (Qnet) were evaluated, on the strength and morphology of the fracture in experimental HSLA Cr-Ni steel welded joints, with commercial (ERS70S-6) filler metal and robotic GTAW technique. The samples were characterized by uniaxial stress tests, stereoscopy and Digital Image Processing (DIP). The results showed that the resistance to fracture of the experimental steel was exceeded by 18.39% by applying Qnet 0.520 (kJ·mm-1) and the combination of: 200 A, 12.7 V, 25 °C and 180 mm min-1, which influenced the ductile fracture morphology and topology. While the low Qnet (0.200-0.208 kJ·mm-1) favors instantaneous deformation of the welded joints with fracture in the weld bead as the major defect.

Prof. M. S. Malinovsky and Prof. M. G. Kushnir. Manual on operative obstetrics. Gosmedizdat. 1931, p. 480, c. 5 p.

After the publication of the last edition of "Operational obstetrics" prof. Many years have passed by Fenomenov, and thus a major defect has arisen in the supply of a practicing obstetrician with a guide to operative obstetrics, which would more or less satisfy the needs of obstetric medical practice. This defect is now becoming even more noticeable for two reasons: 1) the almost complete absence of solid manuals on obstetrics in general, which, for example, should be fully considered "Obstetrics" by prof. V.S.Gruzdev and 2) a significant progressive increase in the number of doctors who have to pay great or exclusive attention to this type of medical care (doctors of special obstetric departments, consultations, medical specialists in large hospitals in factories, factories, state farms, collective farms, district doctors). The lack of manuals and textbooks on obstetrics is especially acute in medical universities, where the mastery of the discipline by students often occurs only "from the words" of the teacher and where, therefore, the activation of teaching methods is reduced to replacing lectures with group tutoring conversations. This is why the release of the peer-reviewed Guideline. However, we think that the work that has appeared should be welcomed also because in itself it is of great value and not only for the student, - the future district doctor, as the authors thought when compiling the Guide, but also for a practical doctor. in his day-to-day obstetric work, and for the postgraduate obstetrician at the Postgraduate Postgraduate Institutes, and for the teacher.

Dopant activation process in Mg-implanted GaN studied by monoenergetic positron beam

A process for activating Mg and its relationship with vacancy-type defects in Mg-implanted GaN were studied by positron annihilation spectroscopy. Mg+ ions were implanted with an energy of 10 keV, and the Mg concentration in the subsurface region (≤ 50 nm) was on the order of 1019 cm−3. After the Mg-implantation, N+ ions were implanted to provide a 300-nm-deep box profile with a N concentration of 6 × 1018 cm−3. From capacitance–voltage measurements, the sequential implantation of N was found to enhance the activation of Mg. For N-implanted GaN before annealing, the major defect species were determined to Ga-vacancy related defects such as divacancy. After annealing below 1000 °C, the clustering of vacancies was observed. Above 1200 °C annealing, however, the size of the vacancies started to decrease, which was due to recombinations of vacancy clusters and excess N atoms in the damaged region. The suppression of vacancy clustering by sequential N-implantation in Mg-implanted GaN was attributed to the origin of the enhancement of the Mg activation.

Identification of the Root Causes for Blowhole Defect in Castings Using Quantitative Risk Ishikawa Diagrams

The primary objective of this work is to reduce blowhole defect occurring in a cast iron transfer box. The transfer box moulds were produced using green sand moulding process, and cores were made using CO2 process. It was found that the transfer box had a rejection rate as high as 60%, and it was mainly due to a blowhole on the top surface of the casting. The Ishikawa and risk Ishikawa diagrams were used to analyze this major defect. The risk Ishikawa diagram was constructed by assigning weights to the major and sub-causes due to which the defect occurs. Further, the probability of risk and its impact values were employed to compute risk scores for the main causes and also global risk. From the work carried out, it was found that that the moulds and the sands along with melting and pouring parameters were the major causes for this defect while damp chill, pouring delays and high moisture content in sand were identified as the root causes for the blowhole defect. The main root cause for the blowhole defect was pouring delay that eventually causes dampness in the chill pieces kept inside the moulds. The remedial measures of keeping the moisture content of the sand within 3.5% and pouring the moulds in the shift II within half an hour after closing them were implemented to eliminate it.

Shewanella oneidensis arcA Mutation Impairs Aerobic Growth Mainly by Compromising Translation

Arc (anoxic redox control), one of the most intensely investigated two-component regulatory systems in γ-proteobacteria, plays a major role in mediating the metabolic transition from aerobiosis to anaerobiosis. In Shewanella oneidensis, a research model for respiratory versatility, Arc is crucial for aerobic growth. However, how this occurs remains largely unknown. In this study, we demonstrated that the loss of the response regulator ArcA distorts the correlation between transcription and translation by inhibiting the ribosome biosynthesis. This effect largely underlies the growth defect because it concurs with the effect of chloramphenicol, which impairs translation. Reduced transcription of ArcA-dependent ribosomal protein S1 appears to have a significant impact on ribosome assembly. We further show that the lowered translation efficiency is not accountable for the envelope defect, another major defect resulting from the ArcA loss. Overall, our results suggest that although the arcA mutation impairs growth through multi-fold complex impacts in physiology, the reduced translation efficacy appears to be a major cause for the phenotype, demonstrating that Arc is a primary system that coordinates proteomic resources with metabolism in S. oneidensis.

Regulation of CHK1 inhibitor resistance by a c-Rel and USP1 dependent pathway

We previously discovered that deletion of c-Rel in the Eμ-Myc mouse model of lymphoma results in earlier onset of disease, a finding that contrasted with the expected function of this NF-κB subunit in B-cell malignancies. Here we report that c-rel -/- Eμ-Myc cells have an unexpected and major defect in the CHK1 pathway, with almost undetectable levels of CHK1 and CLSPN protein leading to therapeutic resistance to the highly specific CHK1 inhibitor (CHK1i) CCT244747. Similar downregulation of CHK1 levels was also seen in CCT244747 resistant U2OS osteosarcoma cells. Further investigation revealed that downregulation of the deubiquitinase USP1 is responsible, at least in part, for these effects. Importantly, we demonstrate that c-rel -/- Eμ-Myc lymphoma cells survive though upregulation of compensatory PI3K/AKT pathway activity. Moreover, targeting this pathway with Pictilisib (GDC-0941) effectively killed c-rel -/- Eμ-Myc in vivo, while having no effect on wild type Eμ-Myc cells. This data reveals an NF-κB regulated pathway controlling CHK1 activity in cancer cells and identifies a potential mechanism for both acquiring and overcoming CHK1i resistance in cancer patients.

Defective membrane repair machinery impairs survival of invasive cancer cells

Cancer cells are able to reach distant tissues by migration and invasion processes. Enhanced ability to cope with physical stresses leading to cell membrane damages may offer to cancer cells high survival rate during metastasis. Consequently, down-regulation of the membrane repair machinery may lead to metastasis inhibition. We show that migration of MDA-MB-231 cells on collagen I fibrils induces disruptions of plasma membrane and pullout of membrane fragments in the wake of cells. These cells are able to reseal membrane damages thanks to annexins (Anx) that are highly expressed in invasive cancer cells. In vitro membrane repair assays reveal that MDA-MB-231 cells respond heterogeneously to membrane injury and some of them possess a very efficient repair machinery. Finally, we show that silencing of AnxA5 and AnxA6 leads to the death of migrating MDA-MB-231 cells due to major defect of the membrane repair machinery. Disturbance of the membrane repair process may therefore provide a new avenue for inhibiting cancer metastasis.

Effects of ultra-high-pressure annealing on characteristics of vacancies in Mg-implanted GaN studied using a monoenergetic positron beam

Vacancy-type defects in Mg-implanted GaN were probed by using a monoenergetic positron beam. Mg ions were implanted into GaN to obtain 0.3-μm-deep box profiles with Mg concentrations of 1 × 1019 cm−3. The major defect species in an as-implanted sample was determined to be Ga-vacancy related defects such as a complex between Ga and N vacancies. The sample was annealed under a nitrogen pressure of 1 GPa in a temperature range of 1000–1480 °C without a protective capping layer. Compared with the results for Mg-implanted GaN annealed with an AlN capping layer, the defect concentration was decreased by the cap-less annealing, suggesting that the surface of the sample was an effective sink for vacancies migrating toward the surface. Depth distributions of Mg after annealing above 1300 °C were influenced by the presence of residual vacancies at this temperature. Hydrogen atoms were unintentionally incorporated into the sample during annealing, and their diffusion properties were also affected by both vacancies and Mg.