Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"lead solder"”.
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Evaluation of Zinc Orthophosphate to Control Lead Solder Corrosion in Waters With High Chloride to Sulfate Mass Ratio
… mass ratio (CSMR) and trigger serious water lead contamination from galvanic lead solder: copper pipe corrosion. Previous attempts to control this problem through simple water chemistry modifications were unsuccessful, but in this work a combination of zinc orthophosphate and moderate …
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Flex Cracking and Temperature-Humidity-Bias Effects on Reliability of Multilayer Ceramic Capacitors
… causes stresses to be transmitted through the solder fillets to the surface mount capacitors. These stresses are the highest at the bottom of the capacitor, where the termination bands end. In order to reduce the amount of stress that is transmitted to the brittle ceramic body of MLCCs through …
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Novel Insights into Lead Corrosion Control: Safely Changing Source Waters, Effective Use of Zinc Phosphate Inhibitors, Electrochemical Reversal of Solder, and Significance of Lead-Polyphosphate Complexation
Recent high profile lead contamination events arising from lead solder corrosion have drawn attention to our alarmingly inadequate understanding of corrosion control chemistry. This dissertation provides novel contributions to an improved understanding of lead corrosion control in four sequential …
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Chloride Sulfate Mass Ratio (CSMR) and Nitrate Acceleration of Galvanic Lead- Bearing Solder Corrosion
Lead corrosion in premise plumbing systems from materials, such as lead pipes, soldered joints, and brass, can cause elevated lead in drinking water. This work examined mechanisms by which galvanic corrosion of lead solder:copper joints is accelerated by high chloride, low sulfate, and high nitrate …
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Novel conductive adhesives for electronic packaging applications: a way towards economical, highly conductive, low temperature and flexible interconnects
… conductive adhesives (ICAs) are promising as a lead-free interconnect material; However, ICAs have a higher resistivity compared to tin/lead solder. The higher resistivity of ICAs results from the large contact resistance between conductive fillers. Several novel approaches to engineer the …
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Reliability evaluation of stacked die BGA assemblies under mechanical bending loads
… printed circuit boards (PCBs) with eutectic tin-lead solder and gold over nickel finishes, both as-reflowed and after aging. The failure envelopes of both types of specimen were quantified in terms of PCB flexural strain and strain rate. The experimental data from cyclic bending tests at three …
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Role of Water Chemistry in Lead Release during Drinking Water Supply and Augmentation
<p>Lead is a toxic heavy metal and legacy contaminant in drinking water that can be released from lead service lines and lead-containing premise plumbing. Lead concentrations in water are sensitive to changes in water chemistry. The extent of lead release is often driven by the solubility of the …
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Understanding Mechanisms of Water Lead Contamination by Nitrate Spallation Corrosion and Lead Removal by Point-of-Use (POU) Filters
Lead enters drinking water by a process of corrosion, dissolution or particle detachment from lead bearing plumbing materials. Preventing contamination of water from lead-tin solder corrosion and achieving effective removal of particulate lead by point-of-use (POU) filters are important public …
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Planar Packaging and Electrical Characterization of High Temperature SiC Power Electronic Devices
… materials, including nano-silver paste, high-lead solder ball and paste, adhesive epoxy, and encapsulant, were introduced and evaluated. The processes such as stencil printing, low-temperature sintering, solder reflowing, epoxy curing, sputtering deposition, electroplating, and patterning of …
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Sources of arsenic and lead in drinking water of Eastport, Perry, and Pleasant Point, Maine
Lead and arsenic in drinking water are a health risk to communities throughout the world; lead can be a problem in houses with old piping systems with either lead piping or 50/50 lead solder, and groundwater in Maine contains high arsenic concentrations. This study sought to determine the …
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Galvanic Lead Corrosion in Potable Water: Mechanisms, Water Quality Impacts, and Practical Implications
As stagnant water contacts copper pipe and lead solder (simulated soldered joints), a corrosion cell is formed between the metals in solder (Pb, Sn) and copper. If the resulting galvanic current exceeds about 2 µA/cm², a highly corrosive microenvironment can form at the solder surface, with pH <2.5 …
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Advancing Fundamental Understanding of Lead-Tin Solder Corrosion in Drinking Water: Nitrate Spallation Mechanism, Inhibition by Zinc Orthophosphate and Free Chlorine, and Implications for Canned Foods
Given rising concern over elevated lead in drinking water in the aftermath of the Flint Water Crisis, forthcoming revisions to the U.S. EPA Lead and Copper Rule (LCR), and federal funding designated for replacing lead service lines, lead-tin solder corrosion control will become increasingly …
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Addressing and Assessing Lead Threats in Drinking Water: Non-Leaded Brass, Product Testing, Particulate Lead Occurrence and Effects of the Chloride to Sulfate Mass Ratio on Corrosion
… over adverse health effects from low level lead exposure motivated reassessment of lead occurrence in drinking water, from the perspective of 1) possibly eliminating lead from new brass materials, and 2) performance testing of existing products. During the course of this thesis work, it was …