Cabot Corporation

About: Cabot Corporation is a company organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Carbon black & Carbon. The organization has 1279 authors who have published 1399 publications receiving 36736 citations.

Analysis of flow between a wafer and pad during CMP processes

Abstract: In this paper, we summarize the development of a numerical model for the chemical mechanical planarization (CMP) process and experimentally investigate the effects of pad conditioning on slurry transport and mixing. A simplified two-dimensional numerical model of slurry flow beneath a stationary wafer was developed to determine the pressure and shear stress beneath a wafer. The initial results indicate that in the hydrodynamic regime a positive upward pressure is exerted on the wafer. We also examined three cases to study pad effects on slurry transport; polishing with an Embossed Politex pad, an unconditioned IC1000 pad, and a conditioned IC1000 pad. Cab-O-Sperse SC1 slurry was used in a 1:1.5 dilution with water. Mixing data show that conditioning has a negligible effect on the rate of slurry entrainment and mixing; however, conditioning has a large effect on the thickness of the slurry layer between the wafer and pad. Conditioning was found to increase the slurry thickness by a factor of two. In addition the gradients in slurry age beneath the wafer were compared among the three cases. The IC1000 pads supported a gradient in the inner third of the wafer only, while the Embossed Politex pad showed a linear gradient across the wafer implying it retains pockets of unmixed slurry in the embossed topography.

Pulmonary alveolar proteinosis and cement dust: a case report.

Abstract: Pulmonary alveolar proteinosis developed in a 29-year-old white man within 2 years of working as a cement truck driver. Pulmonary alveolar proteinosis (PAP), an uncommon respiratory disorder characterized by the accumulation of phospholipid material within the alveoli, has been described in association with exposure to silica, aluminum oxide, and a variety of dusts and fumes. Although a link between exposure to Portland cement and PAP has not been previously noted, this type of cement contains nearly 20% silica. Lung biopsy material, originally used to diagnose PAP, was reviewed under electron dispersive spectroscopy. Analysis indicated the presence of silica particles within the alveolar fluid and macrophages. A number of items support a causal relationship between exposure to cement dust and PAP: (1) the temporal sequence between assuming job duties and the development of the illness, (2) improvement following removal from further exposure, (3) dusty, unprotected working conditions, (4) the presence of silica within the cement, and (5) the alveolar fluid from periodic acid-Schiff-positive lung tissue.

High Surface Area Graphitized Carbon and Processes for Making Same

Abstract: The invention is directed to high surface area graphitized carbon and to processes for making high surface area graphitized carbon. The process includes steps of graphitizing and increasing the surface area of (in either order) a starting carbon material to form high surface area graphitized carbon. The step of increasing the surface area optionally comprises an oxidizing step (e.g., through steam etching) or template removal from composite particles. The invention is also directed to catalyst particles and electrodes employing catalyst particles that are formed from the high surface area graphitized carbon.

Elastomer composite blends and methods - II

Abstract: Elastomer composite blends are produced by novel wet/dry mixing methods and apparatus. In the wet mixing step or stage, fluid streams of particulate filler and elastomer latex are fed to the mixing zone of a coagulum reactor to form a mixture in semi-confined flow continuously from the mixing zone through a coagulum zone to a discharge end of the reactor. The particulate filler fluid is fed under high pressure to the mixing zone, such as to form a jet stream to entrain elastomer latex fluid sufficiently energetically to substantially completely coagulate the elastomer with the particulate filler prior to the discharge end. Highly efficient and effective elastomer coagulation is achieved without the need for a coagulation step involving exposure to acid or salt solution or the like. Novel elastomer composites are produced. Such novel elastomer composites may be cured or uncured, and combine material properties, such as choice of filler, elastomer, level of filler loading, and macro-dispersion, not previously achieved. The coagulum produced by such wet mixing step, with or without intermediate processing steps, is then mixed with additional elastomer in a dry mixing step or stage to form elastomer composite blends. The additional elastomer to the coagulum may be the same as or different from the elastomer(s) used in the wet mixing step.

Materials development for lowering rolling resistance of tires

Abstract: Many countries are implementing regulatory programs to promote the use of transportation technologies that can reduce greenhouse gas emissions and enhance fuel economy of vehicles. These regulatory programs create a need for more durable and fuel-efficient tires. The increased cost of fuel for motor vehicles creates another driving force for improving the fuel economy of vehicles. Commercial vehicle operators recognize that fuel cost is a major driver of the total operating cost; therefore, they increasingly demand tires that are optimized for reducing the fuel cost of a trucking fleet. Rolling resistance of truck tires accounts for about one-third of the power required to move a heavy-duty truck and is the second most important contributor, after engine loss, to the total energy loss of heavy-duty trucks. Other than tire designs, rubber compound hysteresis contributes to the rolling resistance of tires, which affects vehicle fuel economy. There is a significant market demand, due to governmental...