Clean room environment

All substrate preparations prior to the deposition of the organic materials are carried out in a clean room environment to minimize particulates on the anode surface. OLEDs are typically... 

Sample preparation is rather involved. A sample of urine or fecal matter is obtained and treated with calcium phosphate to precipitate the plutonium from solution. This mixture is then centrifuged, and the solids that separate are dissolved in 8 M nitric acid and heated to convert the plutonium to the +4 oxidation state. This nitric acid solution is passed through an anion exchange column, and the plutonium is eluted from the column with a hydrochloric-hydroiodic acid solution. The solution is evaporated to dryness, and the sample is redissolved in a sodium sulfate solution and electroplated onto a stainless steel planchette. The alpha particles emitted from this electroplated material are measured by the alpha spectroscopy system, and the quantity of radioactive plutonium ingested is calculated. Approximately 2000 samples per year are prepared for alpha spectroscopy analysis. The work is performed in a clean room environment like that described in Workplace Scene 1.2. 

Stephanie Boone, a technician at Los Alamos National Laboratory, Chemistry Division Bioassay Program, prepares samples to be electroplated for alpha spectroscopy analysis. The hair net and special lab coat are required for a clean room environment. 

SACHEM Inc., located in Cleburne, Texas, is a producer of high-purity bulk chemicals for companies that have high-purity requirements in their chemical processing. As stated in Workplace Scene 1.2, one of their products is tetramethylammonium hydroxide (TMAH), which is sold to semiconductor industries. The analysis of TMAH for trace anions such as chloride, nitrate, nitrite, and carbonate is critical for SACHEM s quality control laboratory. If these ions are present on the integrated circuit boards manufactured by one of their semiconductor customers, they may cause corrosion severe enough to affect the functionality and performance of the electronic devices in which the circuit boards are used. In SACHEM s quality control laboratory, ion chromatography procedures have been developed to measure the anion concentrations in TMAH. Because the concentration levels are trace levels, a clean room environment, like that described in Workplace Scene 1.2, is used. A special procedure for carbonate analysis is required so that the absorption of carbon dioxide from the atmosphere can be minimized. 

As already stated, for aseptic BFS, the container is filled in a localized air shower provided with sterile filtered air. However, there is a short period of time between container formation and filling, when the open container is transferred from the par-ison formation position to the filling position and exposed to the clean room environment. During this shuttling period, there is a possibility for contaminants from the room environment to enter the container. The air used to form the parison (parison support air) is typically sterile filtered air. If this is not the case, it is also possible for nonsterile air to enter the parison during parison formation. 

Baseline Process. DuPont PI2545, PI2555 and Hitachi PIQ as received from the manufacturer, were spun in a class 100 clean room environment at appropriate spin speeds to achieve 0.5 - 6 y film thickness. The silicon wafer substrates were pre-spun (5K rpm, 30") with 0.05% DuPont VM651 (y-amino propyltriethoxy silane) adhesion promoter in 95/5 (v/v) methanol/HzO. The polyimide film cast on the silane-coated silicon wafer was pre-baked... 

All finished products are tested for sterility in a controlled-access clean room environment in a laminar flow hood, which provides no greater level of a microbial challenge than that encountered in the fill environment. The testing environment consists of a gowning room and sterility test suite that meets the same air quality standards as the hlling suite. 

Beside the identification of single bacterial cell or spores by means of Raman spectroscopy, the localization of these cells inside partly complex matrices has to be performed. One approach is the combination of Raman spectroscopy, fluorescence spectroscopy and digital imaging techniques. This method was applied to detect traces of endospores and other biothreat organisms even in the presence of complex environmental matrices like bioaeroso-lic background, nasal mucin [67], or tap water [68], Another fully automated device was built to analyze bioaerosols in clean room environments, where prior to the Raman identification method a particle preselection took place [69]. 

Since most chromatographic stages are found toward the end of the production process, and because very few matrices are suitable for steam sterilization, product protection must be ensured by locating the equipment within a clean room environment. Often, the temperature of the process must be controlled, typically at 4°C, and so the entire clean room may be cooled to avoid the need for local process cooling. 

A. A major concern when working in a clean room is the generation of particles of the size that cannot be seen and spreading these particles throughout the clean room. Every possible precaution must be taken to contain these contaminants and protect the clean-room environment. Everything that is done as a standard operation must be analyzed to determine if it will adversely affect the cleanroom. If you have any concerns, ask the clean-room monitor before you damage the environment and incur unnecessary clean-up cost. 

The semiconductor industry has become the largest user of automated vision systems. A silicon wafer that will become hundreds of microchips starts as a finely machined disc about 7.9 in (200 mm) in diameter. Before the disc is split into individual chips, the wafer undergoes dozens of steps—some of which are indiscernible by the human eye. To ensure the wafer maintains that sequence, sorting systems using optical character recognition (OCR) identify each wafer, sort it in a clean room environment and report the results to a central network. 

The well-established photon correlation spectroscopy (PCS) uses highly diluted suspensions to avoid multiple scattering. The low concentration of particles makes this method sensitive to impurities in the liquid. So usually very pure liquids and a clean-room environment have to be used for the preparation and operation (ISO 13321 1996, Particle Size Analysis—Photon Correlation Spectroscopy). 

Health issues arise, especially with respect to longterm exposure to low levels of these chemicals. The need for employees to work in a clean-room environment while wearing unwieldy bunny suits to reduce particulate contamination and protect against chemical exposure can also present problems with physical and mental stress, especially given the intense time pressures associated with fabs that run around the clock. 

Most medical plastics must be kept scrupulously clean and are handled only in a clean room environment. Static charge built up on these parts will attract contaminants therefore it is critical that static charges be dissipated. Fillers perform this function because fillers, unlike organic antistatics, have no tendency to migrate and contaminate the surroundings. 

Assembly lines (e.g., medical sector, where products are manufactured in a clean-room environment, assembled, inspected, sorted, and packaged in the same manufacturing cell to avoid any contamination and to guarantee 100 % defect-free production)... 

Plant personnel reacted quickly and extinguished the fire within 10 minutes. However, smoke and water had contaminated the clean room environment where millions of chips were stored for shipment. Some 4,000 miles away, at a Nokia plant outside Helsinki, a production planner who was following a well-defined process for inbound materials failed to get a routine signal from Philips. He contacted the top component purchasing manager. 

Like compression molding facilities, a medical grade extruder is typically maintained in a clean room environment to reduce tiie introduction of extraneous matter into the UHMWPE. The generic schematic of a ram extruder is illustrated in Figure 2.8 (the clean room is not shown). 

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