Research On Water-based Cutting Fluid For Crystalline Silicon Multi-wire Saw

Silicon wafer is the most important and basic raw material for the semiconductor and photovoltaic industries.In recent years,with the semiconductor and photovoltaic industry's rapid development,the quality of silicon processing are also getting higher and higher.Among the many steps in the silicon wafer processing,silicon slicing is the most influential quality of silicon wafer and the highest cost of the process.At present,the mainstream method of slicing silicon is multi-wire slurry saw(MWSS),and compared with the traditional method of inner dimeter(ID)sawing,it has the advantages of higher efficiency,lower slit loss,shallower surface damage,better surface quality,and the better ability to process large-size wafers.Diamond wire saw(DWS)is a new generation of wafer cutting methods developed on the basis of the free abrasive wire saw cutting method,and this process is further enhanced processing efficiency,reduce production costs,reduce environmental pollution,improve the surface quality of the wafer.The diamond abrasive is fixed to the steel wire in DWS,therefore,water-based cutting fluid is essential auxiliary material in the processing.At this stage,domestic enterprises which processing silicon wafer use diamond wire saw water-based cutting fluid are mostly imported products from abroad.The purpose of this paper is to develop a water-based cutting fluid for DWS.Firstly,the components of commercially available diamond wire saw water-based cutting fluid were analyzed.Identify the type of surfactant by using the color change,precipitation,extraction of the dye.Using the method of distillation to separate the solution of cutting fluid,and And analyze it.Separating the cutting fluid sample by using thin-layer chromatography and silica gel column chromatography simultaneously.The pure components were separated and traced by organic wavepot analysis,and determine the molecular structure of each component in the cutting fluid sample.In reference to the DWS water-based cutting fluid analysis results and the characteristics of cutting fluid in sawing process:dispersion,cooling,cleaning,defoaming,wetting,anti-corrosion etc,the formulation of diamond wire saw water-based cutting fluid was studied.The main components of the cutting fluid include dispersants,defoamers,surfactants,corrosion inhibitors,wetting agents,chelating agents,beside water.The performance of the water-based cutting fluid was tested in factory,The test results show that compared with imported cutting fluid self-made cutting fluid does not produce significant bubbles in the sawing process,and it pairs of silicon powder dispersed suspending ability and imports cutting fluid is almost the same.First pass rate of silicon sawing was 93.97%,1.63%higher than the imported cutting fluid did,and the TTV(total thickness deviation),WARP and TV(center thickness deviation)of the silicon wafer those made with self-made cutting fluid are better than those obtained by imported cutting fluid.