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A microelectromechanical systems (MEMS) actuator was selected to study the effects of packaging induced stress on device reliability. In this work, MEMS devices were obtained and packaged using cyanate ester, 96.5/3.5 Sn/Ag, and 92.5/5/2.5 Pb/Sn/Ag die attachment materials. The die attachment materials were then cured or reflowed appropriately and cooled to room temperature which induced stress through the coefficient of thermal expansion mismatches between the silicon die and alumina package. In this work, a MEMS microengine developed at Sandia National Laboratories, which is a device that has been well studied, was selected as a test vehicle to understand the effects of various die attachment solders and related processes parameters on the ultimate functionality of the packaged MEMS microengine. Particularly, the operational lifetime of these devices was measured by testing these devices to failure. These lifetimes were then compared with baseline values to determine the effect of stress on these devices. The maximum stress values observed in these studies ranged from 11–23 MPa based on the die attachment material used for cyanate ester to Pb/Sn/Ag solder, respectively. About 50% of the total population tested failed between 105 and 106 cycles, while 25% failed above 106 cycles and the remaining 25% failed below 105 cycles. The reliability results agreed well with previous results. The effect of stress did not seem to adversely affect the device lifetimes for this class of MEMS device, suggesting that these ranges of solders can be safely used to package MEMS devices.

Nanomechanical silicon cantilever beam test structures were fabricated from silicon-on-insulator wafers using electron beam lithography. A scanning probe system in the form of an atomic force microscope was used to measure their mechanical properties in a non-destructive evaluation approach. It is important to note that, despite the nanometer size of the silicon cantilever beams in the [100] direction, Young's modulus remained unchanged from the bulk value: 179 GPa. We believe that the fabrication processes did not induce any major structural modifications to the basic building blocks of silicon. Hence the Young's modulus was measured to be the same as that of the bulk silicon, which is important for designing predictable structures at nanometer scale.

As applications continue to demand increasingly higher optical output power and longer lifetime, thermo-mechanical stresses on dissimilar materials interfaced for packaging pose an ever-growing challenge for the realization of a durable system. Particularly important for an epitaxy-down configuration is the die-attachment interface, which is desired to be defect free and stress managed for reliable optical alignment. A knowledge of the changes in the physical defect density and magnitude of the thermo-mechanical stress present in the active region as a function of the fabrication process and aging is crucial to an understanding of the influence of the process parameters and operating conditions on device performance and reliability. In this study, we investigated high power laser diode array packages aged under various conditions. Microscopic defect analyses of the die attachment interface and device stress were carried out using primarily metallography, scanning electron microscopy, scanning acoustic microscopy, microhardness, and micro-Raman spectroscopy. It was noted that the intermetallic compounds and microscopic physical defects at the die attach interface are detrimental to transient heat transfer, and thus, overall package reliability. Using micro-Raman spectroscopy, we found that tensile stress near the bar-package interface increases with aging for the first few hundred hours and then decreases with further aging.

A hairline crack was introduced in a 27.9 cm long by 7.62 cm wide by 1.3 cm thick (11 by 3 by 0.5 in.) 6061-4 aluminum specimen by repeated bending. The size of the crack was limited by stopping the bending at the initial stage of crack formation. Measurements were then made using an AC magnetic bridge which detected the presence of the crack and enabled characterization of its form. The extent, the orientation, and the depth from the surface along the crack length were obtained from the measurement. This paper outlines the principle of the bridge operation and details related to interpreting the output from the bridge as the bridge is moved over the surface of the aluminum specimen. Verification of the bridge measurements was made by destructive evaluation of the specimen using a scanning electron microscopic examination.

A general, integral expression is developed which relates measurements of the variations of the imaginary component of complex‐ reluctance with frequency to stress profiles near the surfaces of metals. The technique should yield either applied or residual stress profiles produced, for example, by heat‐treating, metal‐working, fatigue, or peening. It may even be applicable to carburizing. The technique of measurement cancels out the effects of any pre‐treatment residual‐stress profile (subject to the assumption of superposition). The general, integral expression is induced from the results of measurements on a steel bar which is subjected to both tensile tests and bending tests.

Knowledge of the mechanical behavior of strategically important materials such as silicon at nano scale is the key for building next generation devices. In this paper, we investigate the Young’s Modulus of nanomechanical beams [1-8 mm long, 200-400 nm wide, and 193 & 255 nm in thickness] fabricated from silicon-on-insulator (SOI) wafers. The beams of different dimensions were defined in PMMA resist using e-beam lithography. A layer of chrome deposited using lift-off technique, acted as an etch-mask for silicon to fabricate the beams by using RIE. The samples were dipped in BOE (Buffered Oxide Etch) to etch the oxide underneath and the beams were released using critical point drying. Using a Scanning Probe System, nanomechanical beams were bent using AFM silicon tapping mode probes. A controlled amount of force was applied by varying the voltage applied to the Z-axis piezoactuator. The values of beam deflection and the net force applied enabled us to plot the Load vs. Displacement graph for the bending of the nanomechanical beams. Using Euler - Bernoulli beam bending equations, the Young’s Modulus of the Silicon beams was measured to be 174 GPa. This value agrees within 5% of the known value of bulk silicon Young’s modulus of 169GPa. Thus we conclude that the value of Young’s modulus of Si beams does not change when the size is reduced to nanometer regime.

In this paper the authors describe the design considerations including force and tolerance analysis and mechanism and tip design, for a novel, dynamic scanning probe microscopy tip directly insertable into today’s existing atomic force microscopy tools. This tool is the first of its kind and is a major step in the field of nanomanufacturing enabling the use of nanomechanical machining operations for nanostructure top-down manufacturing. The application of this device is the nanomechanical drilling and milling of III-V semiconductor substrates for various applications such as nanovias for electrical interconnection of next generation electronic and photonic applications, as well as reservoirs and capillaries for nano-fluidics. Results to date indicate that device performance parameters allow a normal drilling force of 25 μN, tangential drilling force of 35 μN, maximum rotational speed of 100,000 rpm, and minimum machined feature size of less than 200 nm. This device is currently being fabricated at Sandia National Laboratories, SUMMIT MEMS foundry and being packaged at the University of Arkansas, Fayetteville High Density Electronics Center (HiDEC).Copyright © 2002 by ASME

High power semiconductor laser diodes are finding increasing applications in diverse areas such as the biomedical field, materials processing, cosmetics, etc. Dissimilar materials integration and thermal management are some of the primary challenges in the fabrication and packaging of reliable laser diode systems. For example, in a specific case, a high power diode must be mounted with its epitaxy-side down, so as to achieve efficient heat transfer. The device and package junction, particularly the die attach interface, is desired to be void-free (i.e., micro-defect free), stress-managed, and contamination-free for uniform optical delivery and reliable optical alignment. Soft solders used in optoelectronic applications are typically subjected to extreme service conditions that may exceed two-thirds of the melting point. As a result, it is expected that the solder microstructure will be metastable and subjected to nearly constant modification during processing and device operation. In this study, we investigated high power laser diode packages aged under various conditions. Die attach interface, device stress, and microscopic defect analyses were carried out using primarily metallography, scanning electron microscopy (SEM), scanning acoustic microscopy, and micro-Raman spectroscopy. It was observed that the intermetallic compounds and microscopic physical defects at the die attach interface are detrimental to transient heat transfer, and thus, overall package reliability. Further, accurate device modeling can be used to assist in the overall understanding of the effect of packaging-induced stress on the performance and reliability of semiconductor lasers. The purpose of this modeling work was to better understand the interplay between electrical, optical, mechanical, and thermal effects in the operation of laser diodes. Micro-Raman spectroscopy was employed to explore the degradation of high power lasers due to mechanical stresses that appear in an active region of the diode during its growth, packaging, and operation. Using micro-Raman spectroscopy, we found that, although stress increases with aging, the shape of the stress profile and the strength changes randomly from one active region of the diode to another.

In an effort to better understand and thereby utilize laser processing, an existing code describing laser-metal (aluminum) interaction is modified to describe laser-ceramic (diamond) interaction. Comparisons between our modified code (diamond target) and the original code (aluminum target) highlight similarities and differences between laser-ceramic and laser-metal processing. Gas breakdown effects, which are expected for the simulated short (time duration), high energy laser pulses, are observed in both codes. Due to the lower sublimation heat of aluminum (1.1×104J/g) compared to diamond (5.3×104J/g), aluminum vaporizes more quickly and exhibits a faster expansion speed (1.4×107 cm/sec compared to 8×106 cm/sec for diamond) in the early stage of the laser pulse. Because aluminum requires significantly more energy to fully ionize than does carbon, our simulations show that the diamond plasma is fully ionized (6 of 6 electrons per atom) and the aluminum plasma is partially ionized (11 of 13 electrons per atom).

Alloy 600 tubing is in widespread use in steam generations of nuclear power plants, due to its good high temperature corrosion resistance. It is, however, susceptible to a variety of corrosion damage mechanisms. One of these is tress corrosion cracking (SCC).

Nuclear reactor pressure vessels are clad with a layer of stainless steel approximately 6 millimeters thick. The characteristics of the steel of the pressure vessels are known to change with cumulative radiation exposure from the operating reactor. In situ nondestructive determination of the extent of the changes of the steel characteristics must be made through the stainless-steel cladding. Preliminary tests described here indicate that AC magnetic bridges can differentiate among steels of differing characteristics through stainless cladding.

Coil eddy-current (CEC) technology generates real and complex reactances of the search coil. These reactances are frequently plotted in a complex-impedance (C-I) plane with inductive reactance as the ordinate and resistance as the abscissa. This plane is a useful tool in nondestructive evaluation (NDE), and it is known to virtually all NDE technicians using electromagnetic fields. The complex-impedance plane is generally used to establish the operating conditions for particular eddy-current coils and for particular NDE problems. It can also be used to establish the effect of lift off and to identify flaws.

Hidden corrosion in the seams or below the skin of an aluminum aircraft results in the loss of material and therefore affects the net conductance as measured at the seam or skin surface. This loss of conductance has been detected through the use of electromagnetic techniques, for example, eddy-current techniques [1].

To optimize the sensitivity and minimize lift-off effects of electromagnetic NDE devices requires an understanding of the source and distribution of electromagnetic fields. This understanding is particularly difficult when conductive devices other than the sample are in the vicinity of the field. Such is the case with the modified AC magnetic bridge [1] which has a conducting insert in the vicinity of the gap in proximity to the sample.

A 6-year retrospective investigation elicited patient response to wearing Molloplast-B-lined dentures with the following results: 1. For nearly all the patients wearing a Molloplast-B-lined denture, their ability to wear it comfortably outweighs its disadvantages. 2. Nearly all the patients (95.4%) would elect to have a new soft-lined denture should their present one need replacement. 3. Nearly all the patients (93%) thought that their soft-lined dentures were more comfortable than their previous conventional acrylic resin ones. 4. Molloplast-B-lined dentures offered comfort to a significant number of patients in this study who had had a history of chronic discomfort with the wearing of conventional acrylic resin dentures. 5. The presence of a retracted tongue habit is likely to decrease the patient's satisfaction with the dentures.

An investigation of the behavior of metals during asixymmetric extrusion using the finite element method is presented. Flow characteristics as functions of die shape. die-workpiece interface fricti...

The finite deflection analysis of flexible bars subjected to vertical loads as well as the prediction of the buckling load and post-buckling response in the case of horizontal loading has attract the attention of numerous researchers. Publications related to large deflections of slender beams are referenced in and the monograph contains several applications as well as additional references to previous work. In the present note an efficient finite element procedure is developed for the problem of the elastica including variable loading and foundation stiffness. The effectiveness of the procedure is demonstrated by considering a number of example problems. Because of the generality of the finite element method extensions to more general problems than those presented here can easily be accomplished.

A detailed description of the laboratory processing procedures for Molloplast-B-lined dentures that varies from those offered by the manufacturer has proved to be effective. 1 The processing technique for MolloplastB-lined dentures is very sensitive, consequently, no steps should be omitted. Because these procedures are time-consuming, the minimal time required is 3 full working days in the laboratory.

Chronic granulomatous disease (CGD) is usually a sex-linked recessive disorder characterized by recurrent purulent infections of the skin and lymph nodes. Affected granulocytes form diminished quantities of superoxide 1 and can ingest but not kill catalase-positive bacteria. 2 Granulocytes from patients with CGD fail to reduce nitroblue tetrazolium (NBT) to blue formazin, 3 a defect that forms the basis of tests to identify affected patients and carriers. We describe two children with CGD who had unusual symptoms in order to emphasize the variability of initial signs associated with the disease. Earlier diagnosis coupled with aggressive therapy may improve the outcome in such cases. Report of Cases .—Case1.—An 8-month-old boy was hospitalized in 1974 for evaluation of fever of one month's duration. The child was well until 6.5 months of age when right lower—lobe pneumonia developed. He was referred to The Children's Hospital of Philadelphia because of continued high

A 6-year retrospective investigation was conducted into the serviceability of Molloplast-B-lined dentures with the following results: The Molloplast-B-lined denture is not a temporary expedient but can remain serviceable for a time competitive with that of conventional acrylic resin dentures. All the soft liners were still serviceable after 4 years and 83% after 6 years. The longevity of the soft liner is dependent on correct processing procedures and proper home care. The three liners judged as unserviceable exhibited excessive wrinkling, and all had been soaked in a bleach-type cleanser. The resilience of the liner is dependent on its thickness. The optimum thickness is approximately 3 mm. The resilience of the liner did not decrease with time. No noticeable wear of the soft liner was observed. Staining was present in about half the soft liners. Smoking was commonly associated with staining and odor of the soft liner.

The report was written to provide a sample problem to be used to guide the user of the water droplet impingement prediction computer program. The report is intended to illustrate the preparation of input data and the interpretation of results.

Background: Magrolimab is a humanized monoclonal antibody that blocks the immune checkpoint CD47, a "do not eat me" signal, overexpressed on tumor cells. The binding of magrolimab to CD47 leads to phagocytosis of cancer cells from human solid tumors and hematologic malignancies. The overexpression of CD47 contributes to the pathogenesis of multiple myeloma (MM) and blocking CD47 induces immediate activation of macrophages and elimination of myeloma cells (Sun et al). Hence, a blockade of CD47 with magrolimab may have therapeutic benefit in patients with MM. Combination therapies are more effective than single-agent therapy for both newly diagnosed and relapsed/refractory MM (RRMM). In vitro studies show synergy between magrolimab and daratumumab on MM cell line phagocytosis, and complimentary mechanisms suggest potential enhanced efficacy in other combinations. The current study (NCT04892446) is investigating the efficacy of magrolimab in combination with commonly used myeloma therapies in patients with RRMM. Design and Methods: This phase 2, multi-arm study includes patients aged ≥18 years currently requiring treatment for RRMM; all participants must have received at least 3 previous lines of therapy for MM, including an immunomodulatory drug and a proteasome inhibitor. This study includes 2 phases: a safety run-in cohort and a dose-expansion cohort (Figure 1). The primary objectives of the safety run-in cohort are to evaluate the safety and tolerability of magrolimab in combination with other anticancer therapies using the occurrence of dose-limiting toxicities (DLTs) as the primary endpoint, and to determine the recommended phase 2 dose (RP2D) of magrolimab in the following combinations: magrolimab+daratumumab; magrolimab+pomalidomide+dexamethasone; and magrolimab+bortezomib (maximum of 8 prior cycles in those who previously received bortezomib)+dexamethasone. Dose expansion cohorts will evaluate the efficacy of magrolimab combinations with objective response rate (ORR) as the primary endpoint. Secondary endpoints include duration of response, progression-free survival, and overall survival. Minimal residual disease negativity, biomarker changes from baseline, immune cell signaling alterations, and the mutational profile of plasma cell clones will also be explored. Magrolimab is administered intravenously (IV) with an initial priming dose, followed by a maintenance dose on days 8, 15, 22, and 29 during cycle 1 (35 days) and days 1, 8, 15, and 22 from cycle 2 (28 days) onwards. Daratumumab, pomalidomide, dexamethasone, and bortezomib will be administered according to manufacturer's prescribing information. Dose de-escalation may occur based on DLTs per protocol. Patients will continue treatment until unacceptable toxicity, progressive disease, or patient/investigator choice to discontinue. Planned enrollment is approximately 153 patients. Status: Recruitment is ongoing. Reference: Sun J, Muz B, Alhallak K, Markovic M, Gurley S, Wang Z, Guenthner N, Wasden K, Fiala M, King J, Kohnen D, Salama NN, Vij R, Azab AK. Targeting CD47 as a novel immunotherapy for multiple myeloma. Cancers (Basel). 2020;12(2):305. Figure 1 Figure 1. Disclosures Paul: Amgen Inc.: Speakers Bureau; Bristol Myers Squibb: Divested equity in a private or publicly-traded company in the past 24 months; Genentech: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals Inc: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Regeneron: Membership on an entity's Board of Directors or advisory committees. Liedtke: Celgene: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees, Other: Clinical Trial Funding; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Alnylam: Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria; Takeda: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Kite: Membership on an entity's Board of Directors or advisory committees; Kura Oncology: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees. Monge: Karyopharm Therapeutics: Research Funding; Bristol Myers Squibb: Consultancy. Rifkin: Takeda: Membership on an entity's Board of Directors or advisory committees; Fresenius-Kabi: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; McKesson: Current Employment, Current equity holder in publicly-traded company; Coherus: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb (Celgene): Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Gandhi: Karyopharm Therapeutics: Honoraria; TG Therapeutics: Honoraria; GlaxoSmithKline: Honoraria. Kovacsovics: Janssen Pharmaceuticals: Research Funding; Amgen Inc.: Research Funding; Stemline: Honoraria; Jazz Pharmaceutials: Honoraria; Novartis: Research Funding; AbbVie: Research Funding. Levy: Bristol Myers Squibb: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; GSK: Consultancy, Other: Promotional speaker; Novartis: Consultancy, Other: Promotional speaker; Amgen Inc.: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Honoraria, Speakers Bureau; Gilead Sciences, Inc.: Consultancy, Honoraria, Speakers Bureau; Epizyme: Consultancy, Other: Promotional speaker; Morphosys: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Janssen Pharmaceuticals: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Beigene: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; Takeda: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: Promotional speaker, Speakers Bureau; TG Therapeutics: Consultancy, Honoraria, Speakers Bureau; Dova: Consultancy, Other: Promotional speaker. Siegel: Karyopharm: Honoraria; Celularity: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Speakers Bureau; Takeda: Honoraria; Bristol Myers Squibb: Honoraria, Speakers Bureau; Amgen Inc.: Honoraria; Janssen: Honoraria, Speakers Bureau. Silbermann: Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Sanofi Genzyme: Membership on an entity's Board of Directors or advisory committees, Research Funding. Byrne: Gilead Sciences, Inc.: Current Employment, Current equity holder in publicly-traded company. Ncube: Gilead Sciences, Inc.: Current Employment, Current equity holder in publicly-traded company. Murphy: Gilead Sciences, Inc.: Current Employment, Current holder of stock options in a privately-held company. Gu: Gilead Sciences, Inc.: Current Employment, Current equity holder in publicly-traded company. Rajakumaraswamy: Gilead Sciences, Inc.: Current Employment, Current equity holder in publicly-traded company. Chao: Gilead Sciences, Inc.: Current Employment; TigaTx: Membership on an entity's Board of Directors or advisory committees; Stanford University: Patents & Royalties; Hepatx Inc: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Iconovir Bio: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Leukemia and Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; Stanford University Medical School: Membership on an entity's Board of Directors or advisory committees; Foresite capital: Consultancy; Bioverge: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Chimera Bioengineering: Current equity holder in publicly-traded company. Usmani: Sanofi: Consultancy, Research Funding, Speakers Bureau; Janssen: Consultancy, Research Funding, Speakers Bureau; EdoPharma: Consultancy; GSK: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding, Speakers Bureau; Array BioPharma: Consultancy, Research Funding; SkylineDX: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Takeda: Consultancy, Research Funding, Speakers Bureau; Janssen Oncology: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding; Amgen: Consultancy, Research Funding, Speakers Bureau; Abbvie: Consultancy. OffLabel Disclosure: Magrolimab is an investigational therapy

Two infants who received whole blood filtered through commercially available woven stainless steel micropore filters experienced a sudden onset of hemoglobinuria. The plasma hemoglobin level in one child was 200 mg/dL. To investigate whether filters might lead to RBC destruction, we experimentally quantitated filter-induced hemolysis using standard conditions. Our studies in vitro show that hemolysis decreases with increased speed of transfusion. Hemolysis is particularly extensive with blood stored more than 14 days, but measurable hemolysis occurs with blood stored for as little as one day. (JAMA1982;248:1629-1632)

At the present time the maximum breathing capacity test provides the most significant correlation between symptoms and history of ability to work without pulmonary symptoms, as compared with the vital capacity or three-second timed vital capacity tests. As a study that can be readily performed in the general hospital or physician's office, it offers the most practicable objective guide to evaluation of dyspnea in relation to hard manual labor in coal mining. This conclusion is based on studies carried out in 482 persons, most of whom were soft-coal miners, divided into seven groups by varying degrees of breathlessness in association with physical activity. Similar studies should be done to serve as disability guides for other groups of workers.