According to the research from FM Global (Factory Mutual Insurance Company), most of the incidents that have occurred in semiconductor plants in the past two decades were reported as “Fire Cases”. They claim that the fires in wet chemical cleaning processes were mainly caused by heater failure. However, depending on the process conditions, electrical heaters are designed to turn off automatically when the temperature reaches a set point. Therefore, a thorough study of the situations related to possible fires in wet chemical cleaning processes is necessary.
This study focused on the incompatible behaviors of cleaning materials used in the wet bench stage. These results can be applied to determine the causes of fires in the wet bench stage from using reactive chemicals for cleaning purposes.
Another purpose of this study was to investigate the potential hazards of widely used chemicals (hydrogen peroxide, concentrated sulfuric acid, hydrochloric acid and isopropyl alcohol) within similar processes in semiconductor plants. Experimental data were also verified in order to establish a concentration triangular diagram, which could be used to identify a combustion, deflagration or even detonation zone. Finally, this study can provide basic design data for an inherently safer process to avoid potential hazards caused by dangerous mixtures, which may result in large property loss in semiconductor plants. 相似文献
Fluoride and arsenic are major anionic elements of concern in drinking water treatment. The effects of contact time, pH, surface
loading and ionic strength on adsorption of fluoride and As(V) were investigated using batch methods. Adsorption of fluoride and
As(V) onto goethite obeyed a pseudo second-order rate law. Through experimental data and adsorption kinetic analysis, the affinity of
As(V) onto goethite was stronger than fluoride. Fluoride and As(V) uptake by goethite all decreased with pH increasing at the same
surface loading; however, ionic strength had slight influence on their adsorption. A surface sites-species model was used to quantify
the adsorption of fluoride and As(V) onto goethite as function of pH and surface loading. This model can satisfactorily predict their
adsorption characteristics with several adsorption constants. 相似文献
The variations of sulfate formation and optical coefficients during SO2 heterogeneous reactions on hematite surface under different SO2 concentrations were examined using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatograph (IC). Laboratory experiments revealed that within ambient SO2 of 0.51–18.6 ppmv, sulfate product, producing velocity, absorption and backward scattering coefficients showed an increasing trend with SO2 concentration. Under given SO2 concentra... 相似文献