Shape evolution of electrodeposited bumps with deep cavity

Electrodeposited bumps are the indispensable microconnectors for high-density interconnection in the latest microelectronics applications. The deep cavities are especially important for the solder bumps for ball grid arrays. This investigation discusses the relation between cavity shapes and current distributions of deep cavities. The role of convection and diffusion within the cavities is calculated at diffusion-limited overpotentials with numerical fluid dynamics computations. The current distributions become symmetric and peak profiles become sharper for the deeper cavities of large aspect ratios and of negative photoresist angles, theta. For 30 mu m cathode length, the current at the center is larger than that at the edges for photoresist angles of theta less than or equal to 0. For these deep cavities, the convection outside the cavity is not related to the current distribution and the current distribution is determined by the cavity shape. The mass transport within the deep cavities is controlled mainly by diffusion. This is because the convection outside the cavities is not effectively stirring inside the deep cavities.</p

A Time-Space Analysis of Urban Activities with Focus on the Relationship between ICT and Activity-Travel

Information and communications technology (ICT) has evolved substantially and impacted urban residents’ everyday life quite substantially in the past decade. The rapid spread of mobile telecommunications technologies has produced significant changes in relationships among communications, marketing and distribution, and transportation. As mobile technologies diminish time-space constraints that have governed telecommunication, they are prompting the emergence of new life styles with unprecedented ways in which urban space is consumed. The focus of this study is on how mobile telecommunication technologies have influenced daily activity and travel behaviors of urban residents. Temporal and spatial characteristics of their activity-travel patterns are empirically analyzed using activity diary data sets collected by the authors in the Kofu area of Japan. The survey is designed with the intent of capturing both patterns of movements in the urban area and patterns of activities that induced the movements. Questions regarding telecommunications activities are introduced into the activity-travel diary that had been developed by the authors to facilitate the acquisition of information on the occurrence and contents of telecommunications activities. The analytical framework of this study is formed by integrating urban residents’ time-space paths and virtual links representing telecommunications activities. Time-space paths are formed in a physical urban space while satisfying temporal and spatial constraints imposed by Hägerstrand’s prism. Conventional means of inter-individual communication (meeting, stationary telephones, mailed letters and telegrams) are all subject to certain constraints in the time-space domain. On the other hand, telecommunications activities by mobile technologies are not subjected to many of the constraints and can influence travel decisions more spontaneously than do conventional means of communication. Several hypotheses concerning ICT and activity patterns are postulated and empirically examined with the results of the diary surveys. Examples of the hypotheses are as follows. As the use of mobile telecommunications technologies increases, 1) the activity frequency tends to increase, 2) the spatial distribution of activities tends to spread out, that is, the action space tends to expand spatially, and 3) patterns of trip chaining tend to change themselves, with more stops incorporated into a home-based trip chain (i.e., a sequence of trips starting from and ending at home, through which a set of activity locations are visited). It is also hypothesized that 4) the way mobile technologies influence the individual’s activity-travel patterns varies by his personal characteristics, especially life cycle stage and life style. The Survey of Communication, Activity and Travel, denoted by “SCAT,” was conducted twice to form the database of this study. The first survey involved about 150 university students and data on weekly activity patterns and mobile telecommunication incidents were collected. The second survey addressed about 150 households (322 individuals) and activity diaries on two consecutive days and mobile telecommunication information were obtained. The first SCAT data are used to examine basic properties of ICT–activity-travel relationships of “heavy mobile-informed travelers” because students are certainly standing on the forefront of ICT use. On the other hand, the second SCAT data are used to analyze characteristics of joint activity engagement by household members as a result of ICT use among household members. Then, using both of the SCAT data sets, the hypotheses are examined and statistical evidence is presented. Finally, implications of the findings are summarized and directions are suggested for future research on ICT, activity and travel.

A collimated jet and an infalling-rotating disk in G192.16-3.84 traced by H2O maser emission

We report H2O masers associated with the massive-star forming region G192.16-3.84 observed with the new Japan VLBI network at three epochs spanned for two months, which have revealed the three-dimensional kinematical structure of the whole \h2o maser region in G192.16-3.84, containing two young stellar objects separated by ~1200 AU. The maser spatio-kinematical structure has well persisted since previous observations, in which the masers are expected to be associated with a highly-collimated bipolar jet and an infalling-rotating disk in the northern and southern clusters of H2O maser features, respectively. We estimated a jet expansion speed of ~100 km/s and re-estimated a dynamical age of the whole jet to be 5.6x10^4 yrs. We have investigated the spatial distribution of Doppler velocities during the previous and present observations and relative proper motions of H2O maser features in the southern cluster, and a relative bulk motion between the two maser clusters. They are well explained by a model of an infalling-rotating disk with a radius of ~1000 AU and a central stellar mass of 5-10 M_sun, rather than by a model of a bipolar jet perpendicular to the observed CO outflow. Based on the derived H2O maser spatio-kinematical parameters, we discuss the formation mechanism of the massive young stellar objects and the outflow development in G192.16-3.84.Comment: 30 pages, 3 figures, 3 tables, to be published in the Publication of the Astronomical Society of Japan issued on 2006 October 2

Electrodeposition of Zinc-SiO2 composite

The incorporation mechanism of SiO2 particles into zinc electrodeposit is discussed. The SiO2 particles precipitate in two ways on the (00-1)(eta) of zinc electrodeposit: by lined up particles along the laterally growing macrosteps on the (00.1)(eta) and by randomly dispersed particles on the (00.1)(eta). These particles incorporate into the electrodeposits by following two processes. The sidewalls of particles are incorporated into the macrosteps at the edge of (00.1)(eta). The bottom of randomly dispersed particles are incorporated into the (00.1)(eta) probably by the atomic steps. (C) 2000 The Electrochemical Society.</p

Pharmacokinetics and pharmacodynamics of prasugrel in healthy Japanese subjects

AbstractThis randomized double-blind and placebo-controlled study assessed the pharmacodynamics and pharmacokinetics of prasugrel in healthy adult Japanese male subjects after single (n = 50) and multiple (n = 40) oral administration. With a single administration of prasugrel (2–30 mg), the plasma concentration of the active metabolite increased rapidly, reached a maximum at 30 min after administration, and then decreased rapidly within 4 h. The 5 mg and higher doses prevented ADP-induced platelet aggregation in a dose-dependent manner. Further analyses showed that 30 mg prasugrel exhibited the peak inhibition, and 20 mg prasugrel showed a nearly equivalent effect. With multiple doses (2.5–10 mg), the pharmacokinetic parameters on Day 1 and Day 7 were similar, and no accumulation attributable to multiple dosing was observed. The inhibitory effect on ADP-induced platelet aggregation increased with doses from 2.5 to 7.5 mg, and reached the peak level at 7.5 mg. Regarding safety, all of the drug-related adverse events observed were mild, and there were no clinically significant bleeding-related adverse events. This study indicates that a single oral administration of prasugrel at a dose of up to 30 mg and a maintenance dose of up to 10 mg are tolerated in Japanese healthy subjects

Shape evolution of electrodeposited copper bumps with high peclet numbers

We report the shape evolution of initial copper bumps at Peclet numbers higher than a hundred. The role of vortices and of penetration flow within the cavity was discussed with numerical fluid dynamics computation to obtain a bump with a single hump at the center. The current distributions, or flux profiles, were calculated at the diffusion controlled overpotential and were compared with the electrodeposited bump shapes. For the 100 mu m cavity width, the vortices increase at the upstream corners with Peclet numbers 1410 and 7311. The vortices are the local resistance of mass transfer to the cathode. These vortices cause the hollows in flux profiles at the upstream corner with these Peclet numbers. The penetration flow collides with the photoresist sidewall and the vortices decrease at downstream corners. These decreased vortices cause the increase in flux profile at downstream corners. For a 30 pm cavity width a single large vortex forms for the higher Peclet number 44,500 and a single hump in flux is achieved.</p

An intrathoracic scapular prolapse with hemorrhagic shock after a thoracotomy

We herein present a case in which an emergency operation was performed for an intrathoracic hemorrhage resulting from a scapular prolapse after a thoracotomy, a rare complication of this procedure. A 59-year-old man had undergone a right upper lobectomy with an extended resection of the posterior chest wall including the second to fourth ribs due to a direct invasion by a lung cancer. On postoperative day 80, we performed an emergency operation as the patient had gone into shock due to an intrathoracic hemorrhage with a right scapular prolapse. The scapula protruded through the enlarged fourth intercostal space. The prolapsed scapula was reduced and the defect in the chest wall was covered with Marlex mesh.ArticleINTERACTIVE CARDIOVASCULAR AND THORACIC SURGERY. 12(2):326-327 (2011)journal articl

Current evolution of electrodeposited copper bumps with photoresist angle

We report the current distribution of copper bumps with photoresist sidewall angles. The role of outer diffusion, vortices, and penetration flow within the cavity is discussed, with numerical fluid dynamics computed in order to prevent side bumping. The current distributions were calculated at the diffusion controlled overpotential. The mass transfer-limited current distribution showed that a zero or negative angle reduced diffusion from the outer surroundings and enhanced vortex formation at the cathode corners. Reduction in the diffusion and enhancement in vortices reduced current at the cathode corners and prevented side bumping.</p

Crystal growth of electrolytic cu foil

Electrolytic copper deposited on (100)(Cu) single crystals forms pyramidal crystals that grow parallel to the substrate at low current density without stirring. With stirring and higher current density, slanting platelet crystals with (111)(Cu) orientation are formed. Chloride and gelatin are typical additives for electrolytic copper foils and the electrolytic copper foils are formed on a titanium substrate with a stirring rate and high current density. With gelatin, triangular pyramidal crystals form with (111)(Cu) orientation. The triangle-shaped side planes of the crystals are the (100)(Cu), and platelet crystals exist along the (100)(Cu). With chloride and gelatin, triangular columnar crystals with the (110)(Cu) orientation are formed. The triangle-shaped side planes of the crystals are the (100)(Cu) and the platelet crystals again exist along the (100)(Cu). These platelet crystals are bound by macrosteps, and they are the growth sites. The morphology of electrolytic copper foils on the titanium substrate does not change with higher current densities and stirring rates. It was also found that chloride changes deposit orientations in the concentration range of less than 10 ppm. (C) 2004 The Electrochemical Society. </p