On-line quality monitoring and lifetime prediction of thick Al wire bonds using signals obtained from ultrasonic generator

Abstract The reliable performance of power electronic modules has been a concern for many years due to their increased use in applications which demand high availability and longer lifetimes. Thick Al wire bonding is a key technique for providing interconnections in power electronic modules. Today, wire bond lift-off and heel cracking are often considered the most lifetime limiting factors of power electronic modules as a result of cyclic thermomechanical stresses. Therefore, it is important for power electronic packaging manufacturers to address this issue at the design stage and on the manufacturing line. Techniques for the non-destructive, real-time evaluation and control of wire bond quality have been proposed to detect defects in manufacture and predict reliability prior to in-service exposure. This approach has the potential to improve the accuracy of lifetime prediction for the manufactured product. In this thesis, a non-destructive technique for detecting bond quality by the application of a semi-supervised classification algorithm to process signals obtained from an ultrasonic generator is presented. Experimental tests verified that the classification method is capable of accurately predicting bond quality, indicated by bonded area as measured by X-ray tomography. Samples classified during bonding were subjected to both passive and active cycling and the distribution of bond life amongst the different classes analysed. It is demonstrated that the as-bonded quality classification is closely correlated with cycling life and can therefore be used as a non-destructive tool for monitoring bond quality and predicting useful service life

On-line quality monitoring and lifetime prediction of thick Al wire bonds using signals obtained from ultrasonic generator

Abstract The reliable performance of power electronic modules has been a concern for many years due to their increased use in applications which demand high availability and longer lifetimes. Thick Al wire bonding is a key technique for providing interconnections in power electronic modules. Today, wire bond lift-off and heel cracking are often considered the most lifetime limiting factors of power electronic modules as a result of cyclic thermomechanical stresses. Therefore, it is important for power electronic packaging manufacturers to address this issue at the design stage and on the manufacturing line. Techniques for the non-destructive, real-time evaluation and control of wire bond quality have been proposed to detect defects in manufacture and predict reliability prior to in-service exposure. This approach has the potential to improve the accuracy of lifetime prediction for the manufactured product. In this thesis, a non-destructive technique for detecting bond quality by the application of a semi-supervised classification algorithm to process signals obtained from an ultrasonic generator is presented. Experimental tests verified that the classification method is capable of accurately predicting bond quality, indicated by bonded area as measured by X-ray tomography. Samples classified during bonding were subjected to both passive and active cycling and the distribution of bond life amongst the different classes analysed. It is demonstrated that the as-bonded quality classification is closely correlated with cycling life and can therefore be used as a non-destructive tool for monitoring bond quality and predicting useful service life

Mitochondrial Transplantation Attenuates Toxicity in Human Lymphocytes Caused by Clozapine and Risperidone

Background: Clozapine (CLZ) and risperidone (RIS) are drugs that have the ability to disrupt mitochondrial function. Also, these drugs increase the level of free radicals. Mitochondrial dysfunction plays a role in the etiology of various diseases. Replacement and treatment of defective mitochondria with healthy mitochondria have been considered. Mitochondrial therapy (mitotherapy) or exogenous mitochondria transplantation is a method that can be used to replace dysfunctional mitochondria with healthy mitochondria. This method can help in the treatment of diseases related to mitochondria. Methods: In this study, we investigated the transplantation effect of isolated lymphocyte mitochondria on the toxicity induced by CLZ and RIS on human blood lymphocytes. Lymphocytes were isolated using the Ficoll standard method. Mitochondria of human lymphocytes were used for mitotherapy. This study was conducted in 6 groups. After treatment, the level of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), reduced glutathione (GSH) content, oxidized glutathione (GSSG) content, and adenosine triphosphate (ATP) content were evaluated. Results: Our data showed that CLZ (70 µm) and RIS (24 nM) caused cytotoxicity on human blood lymphocytes which are associated with ROS generation, collapse in MMP, decrease in GSH content, increase in GSSG content and change in ATP content. Mitochondria transplantation results showed that adding mitochondria of lymphocytes could protect the lymphocytes against the toxicity effects caused by CLZ and RIS. Furthermore, the results showed that pre-incubation with cytochalasin D considerably reserved the protective effects of mitotherapy in the human lymphocytes. Conclusion: We proposed that mitochondria transplantation or mitotherapy-affected blood lymphocytes with exogenous mitochondria could be used to treat CLZ and RIS-induced toxicity

Emotional Eating and Changes in High-Sugar Food and Drink Consumption Linked to Psychological Distress and Worries: A Cohort Study from Norway

Psychological distress is linked to unhealthy eating behaviors such as emotional eating and consumption of high-sugar food and drinks. Cross-sectional studies from early in the COVID-19 pandemic showed a high occurrence of worries and psychological distress, and this was associated with emotional eating. Few larger studies have examined how this coping pattern develops over time. This cohort study with 24,968 participants assessed changes over time in emotional eating, consumption of sugary foods as an example of unhealthy food choices, and consumption of fruits and vegetables as an example of healthy food choices. Further, associations between these and psychological distress, worries, and socio-demographic factors were assessed. Data were collected at three time points (April 2020, initially in the COVID-19 pandemic, then one and two years later). Emotional eating and intake of sugary foods and drinks were high at the start of the pandemic, followed by a reduction over time. High psychological distress was strongly associated with higher levels of emotional eating and high-sugar food intake, and lower levels of healthy eating habits. The strength of this association reduced over time. Our findings indicate the high frequency in unhealthy food choices seen early in the COVID-19 pandemic improved over time.publishedVersio

A thermal cycling reliability study of ultrasonically bonded copper wires

In this work we report on a reliability investigation regarding heavy copper wires ultrasonically bonded onto active braze copper substrates. The results obtained from both a non-destructive approach using 3D X-ray tomography and shear tests showed no discernible degradation or wear out from initial conditions to 2900 passive thermal cycles from − 55 to 125 °C. Instead, an apparent increase in shear strength is observed as the number of thermal cycles increases. Nanoindentation hardness investigations suggest the occurrence of cyclic hardening. Microstructural investigations of the interfacial morphologies before and after cycling and after shear testing are also presented and discussed

Patient safety improvement with the patient engagement in Iran: A best practice implementation project.

BackgroundPatient engagement in patient safety is aimed at increasing the awareness and participation of patients in error-prevention strategies. The aim of this project was to improve the patient safety with the patient engagement within the local context of a maternity hospital by implementing best practice.MethodsA clinical audit was conducted using the JBI Practical Application of Clinical Evidence System tool. The current project was conducted in surgical ward of Shahid-Beheshti maternity hospital, Iran. The sample size was 46 patients and 46 healthcare practitioners for both the baseline and follow-up. In phase 1, four audit criteria were used and a baseline audit was conducted for this project. In phase 2, barriers to compliance were identified, and strategies were adopted to promote best practice. In phase 3, a follow-up audit was conducted.ResultsThe results showed varying levels of compliance with the four criteria used in this project. The criterion 1, which was related to training of healthcare practitioners on how they can support patients, has the highest compliance at 87% in baseline and follow up data collection. Furthermore, compared with the baseline data (criterion 2 = 52%; criterion 3 = 37%; criterion 4 = 61%), compliance with criteria 2, 3, and 4 notably improved at 85, 76, and 92%, respectively.ConclusionsThe present project successfully implements patient engagement in Iran and reveals varying results on compliance and the increasing knowledge of healthcare practitioners and patients on evidence-based patient engagement in order to improve the patient safety. The used strategies can facilitate implementation of evidence based procedures in clinical practice

A comprehensive review on various aspects of SARS-CoV-2 (COVID-19) vaccines

This is a comprehensive review based on the published papers in the field of COVID-19 vaccines and vaccination. Many efforts have been made to develop vaccines to combat this pandemic. Since December 2020, more than 200 vaccines have been tested in various research stages and in clinical trials on humans, of which eight vaccines reached phase four clinical trials in humans and approved by FDA and EUA. After the Pfizer-BioNTech vaccine that had the highest efficacy (95), the efficacy of the other vaccines are as follows: Moderna 94.5, Sputnik V 91, Novavax 89.7, Sinopharm 79.3, Oxford/AstraZenaca 70.4, Johnson and Johnson 66.9, and Sinovac 50.7. At present, protein-based vaccines, with 35 of all available COVID-19 vaccines, are the most common technique in the vaccine production, and then there are vaccines of non-replicating viral vector (13.3), mRNA1 (12.1), DNA (10.2), replicating viral vector (9.8), and inactivated vaccines (8.2). The most frequently recognized adverse effects within 7 days of each vaccine dose involved fever, fatigue, headache, chill, and myalgia. The mRNA-based vaccines were associated with a higher occurrence of local side effects (78.3 vs. 70.4; Sig. = 0.064), whereas the viral vector-based vaccine was associated with a higher prevalence of systemic side effects (87.2 vs. 61; Sig. < 0.001). Based on the evidence and articles in the field of vaccination, AstraZeneca-Oxford and Sinopharm vaccines reported the highest and lowest side effects, respectively. Because of being emerging, pathogenicity, and high infectivity of COVID-19, vaccination against the disease to prevent its incident rate and decrease the prevalence rate is recommended immediately. Being informed of various aspects of the existing vaccines such as efficacy, effectiveness, safety, etc.can accelerate to make effective and useful choices and consequently have a vaccinated community against the epidemic