Stitch Bond Process of Pd-Coated Cu Wire: Experimental and Numerical Studies of Process Parameters and Materials

Cost reduction is the main driver in the recent transition to Cu wire bonding from predominate Au wire bonding. Other cost reduction in packaging comes from new developments in substrates and lead frames, for example, Pre-Plated Frames (PPF) and uPPF for QFP and QFN reduce the plating and material cost. However, 2nd bonds (stitch bonds) can be more challenging on some of the new leadframe types due to the rough surface finish and thin plating thickness. Pd-coated Cu (PCC) wire has been recently introduced to improve the wire bonding process with bare CU wire, mainly to improve reliability and enhance the stitch bond process. More fundamental studies are required to understand the influences of bonding parameters and bonding tools to improve stitch bondability. The stitch bond process of 0.7 mil diameter PCC wire on Au/Ni/Pd-plated quad flat-no lead (QFN) PPF substrate is investigated in this study. Two capillaries with the same geometry but different surface finishes are used to investigate the effect of capillary surface finish on the stitch bond process. The two capillary types are a polished finish type which is commonly used for Au wire bonding, and a granular finish capillary that has a much rougher surface finish. Process window between no stick on lead (NSOL) and short tail is compared. The effect of process parameters including bond force and table scrub amplitude is studied. The process window test results revealed that the granular capillary has larger process window and a lower chance of short tail occurrence. It has been shown that a higher scrub amplitude increases the chance of successful stitch bond formation. To further compare the capillary surface finishes, 3 sets of parameter settings with different bond force and scrub amplitude are tested. For all three parameter sets tested, the granular capillary showed better quality in bond strength. The granular capillary resulted in higher stitch pull strength compared to the polished type. A finite element model (FEM) of the process was developed to better understand the experimental observations. The amount of surface expansion (plastic deformation) of the wire at the wire and substrate interface was extracted from the model and attributed to the degree of adhesion (bonding). The model was used to confirm the experimental observation of adhesion (bonding) with different surface finish

Prospectus, September 22, 1982

STUDENT VOTE SHOULD BE EXERCISED; News Digest; Election candidates present platforms; Children\u27s theater group performs new play; College remark causes reaction; Annex gets approval; C-U Happenings…; Club designed for business students; Bike is victim of \u27dastardly deed\u27; Microprecision department one of few in U.S.; Hough now teaches class; Community Calendar; Classified; Problem lyrics can\u27t overshadow great music; Hot Country Singles; TV season may bring surprises; TH\u27s delight CU at AH; Abbey\u27s job has variety; White leads for Parkland; ISU transfer looks like an asset; Fast Freddy Contesthttps://spark.parkland.edu/prospectus_1982/1010/thumbnail.jp

Prospectus, October 20, 1982

JUDGES FOR CONTEST NAMED; News Digest; StuGo plans trip to Purdue; PCF president speaks out on letters; \u27Draft registration is law,\u27 says student; Lack of control to blame; We asked Parkland students what their TV viewing habits were and whether school or jobs made a difference in what they watched.; Soaps watched in groups; C-U Happenings...; TV lab instructor named; 74 bands to gather in CU; Gadgetry comes into the home via TV; Brat fest set; TV Find; Midterm grades out soon; The Prospectus...at work; SNL writer responsible for TV teens; Classified; Too much Rush, too little Rory; Old favorites may face serious challenges: The race is on for number one network spot; News In Music; Fact, fantasy, fun scheduled for fall; NCAA faces court battle in TV contract suit; Fast Freddy Contest; Fast Freddy\u27s picks; Sports Shortshttps://spark.parkland.edu/prospectus_1982/1007/thumbnail.jp

BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis

Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

Mapping of cortico-thalamic circuits at high spatiotemporal resolution during a spreading depolarization with functional ultrasound imaging and flexible electrode array in rats

status: publishe

Prospectus, September 15, 1982

PROSPECTUS FOCUS: MONTICELLO; News Digest; Parkland graduate editor of Monticello weekly: Paper serves community; Bell calls for change; Change called for; Parkland deserves your loyalty too; Community Calendar; Sadorus photos in gallery display; C-U Happenings...; Classified; Places and Faces in Monticello...; Record Reviews: The kids are still alright, Solo album brings old sound back: Zeppelin revived; Zapp tops soul list; Garp according to Williams good blend of joy, sorrow; Python lovers get best film to date; Freddy returns to match wits with fans; Cobras hit links, season openshttps://spark.parkland.edu/prospectus_1982/1011/thumbnail.jp

Association of Ultraviolet Radiation Exposure with Dermatomyositis in a National Myositis Patient Registry.

OBJECTIVE: Dermatomyositis (DM) has been associated with geospatial differences in ultraviolet (UV) radiation, but the role of individual determinants of UV exposure prior to diagnosis is unknown. METHODS: We analyzed questionnaire data from 1350 adults in a U.S. national myositis registry (638 with DM, 422 polymyositis [PM], and 290 inclusion body myositis [IBM] diagnosed at ages 18-65 years), examining the likelihood of DM compared with PM and IBM diagnosis, in relation to self-reported sunburn history and job- and hobby-related sun exposures in the year prior to diagnosis. We estimated odds ratios (OR) and 95% confidence intervals (CI) using logistic regression adjusted for age, skin tone, and sex, to determine the association of individual UV exposures with DM diagnosis. We also evaluated the proportion of DM by maximum daily ambient UV exposure, based on UV-B erythemal irradiances for participant residence the year prior to diagnosis. RESULTS: DM was associated with sunburn in the year before diagnosis (two or more sunburns, OR=1.77; 95%CI 1.28, 2.43 vs. PM/IBM; one sunburn OR=1.44; 95%CI 1.06, 1.95) and with having elevated job- or hobby-related sun exposure (high OR=1.64; 95%CI 1.08, 2.49 or moderate exposure OR=1.35; 95%CI 1.02, 1.78 vs. low or no exposure). Ambient UV intensity was associated with DM in females (beta=3.97, P=0.046), but not overall. CONCLUSION: Our findings suggest that high or moderate personal exposure to intense sunlight is associated with developing DM compared with other types of myositis. Prospective research on UV exposure as a modifiable risk factor for DM is warranted. This article is protected by copyright. All rights reserved