Research On Preparation And Properties Of Gel Polishing Pad In Sodium Alginate System

In order to obtain super-smooth and perfect surface with high-precision,the ultra-precision polishing technology for semiconductor substrate materials is still dominated by abrasive processing.As a kind of semi-consolidated abrasive polishing technology,gel flexible polishing technology has the advantages of high efficiency and environmental protection in manufacturing.However,there are still breakage and dehydration cracking of gel matrix of sodium alginate during processing and storage.Although the improvement of gel properties and abrasive holding force can be achieved by means of inorganic chemical addition,it is still necessary to further solve the failure problem of the sol-gel polishing tool from the intrinsic properties of the gel matrix.According to the above problems,based on the gel flexible polishing technology,combined with the research on the gel performance enhancement methods in various fields,this paper selects the appropriate system of sodium alginate composite materials and coated substrate,and adjusts the preparation parameters like the size and concentration of abrasive,the thickness of the gel,etc.,to achieve the gel polishing pad preparation in form of single-layer or multi-layer abrasive.The main research contents of the thesis include: the selection of materials for gel polishing pad in sodium alginate system,the influence of different preparation parameters on the abrasive dispersion and adhesion of single-layer abrasive spray gel polishing pad,and the influence of system changes on processing results and wear conditions of gel polishing pad.Through experimental research and analysis,it is found that the binary compounding form of sodium alginate system can exhibit complementary functions and synergistic effects,which can improve the water holding capacity of the gel polishing pad.The coated substrate should be of a mesh or woven structure with a proper amount of fluff on the surface to improve the adhesion with the gel and reduce the breakage of the gel.With a nozzle height of 65 mm,a rotating disk speed of 120 rpm,sliding table speeds after step speed regulation in the range of 12mm/s～60mm/s,a gel coating thickness requirement of less than 0.6mm,1wt.% of W5 diamond abrasive as the main preparation parameters,can obtain a single-layer abrasive spray type gel polishing pad with uniform abrasive dispersion uniformity and good adhesion.Comparing the processing of silicon carbide substrate with different system of gel polishing pad,it is found that the advantage of dry polishing in gel polishing pad of composite system is obvious,and the damage and shedding phenomenon is reduced.In the process of dry and wet polishing,the new tool preparation system of gel polishing pad has better processing strength,which can reduce the failure of the polishing pad.