Study On Aluminum Nitride Hydrated Processed By SG Polishing Film

Aluminum nitride has some excellent properties,such as high heat conductivity,nontoxic and high temperature resistance,thermal expansion coefficient close to silicon,therefore,these advantages make aluminum nitride an ideal structural packaging material for electronic industry,but the ultra-smooth machining of the aluminum nitride surface is of great difficulty.Fixed abrasive machining causes great damage on the surface,the abrasive tool wear is severe during processing,and the ultra-fine abrasive dispersion is not uniform.Free abrasive is wasted seriously in the process,the ultra-fine abrasive is inclined to reunite,resulting in low efficiency,and meanwhile,the polishing solution will lead to environment pollution.Based on the characteristic of aluminum nitride hydrolysis reaction,a kind of semi-consolidation polishing tool sol-gel(SG)polishing film is applied to process aluminum nitride.In this paper,an automatic rotating scraping device is designed to prepare SG polishing film.The aluminum nitride substrate was processed by SG polishing film in dry polishing and wet polishing,the effect of SG polishing film on aluminum nitride was studied in aspect of surface quality change and material removal rate.The machining effect of SG polishing film on poly-crystalline and mono-crystalline aluminum nitride was studied,the influencing factors of aluminum nitride hydration reaction was discussed and the kinetic friction coefficient between the SG polishing film and aluminum nitride was measured,the debris of aluminum nitride in the process is collected and detected.The morphology change of SG polishing film after dry polishing and wet polishing was observed.The automatic rotating scraping device designed in this paper can accurately control the thickness of SG polishing film and improve the film formation efficiency.From the change of surface quality of aluminum nitride by SG polishing film in dry polishing and wet polishing,a semi-solid abrasive polishing tool is feasible to process aluminum nitride.The high material removal rate is pursued in aluminum nitride substrate coarse polishing stage with rapid realization of aluminum nitride substrate surface planarization,SG polishing film dry polishing processing is applied to process the aluminum nitride substrate in coarse polishing stage,because material removal rate is as high as 14.456 um/h;High surface quality of aluminum nitride substrate is pursued in the fine polishing stage,SG polishing film wet polishing is suitable for fine polishing of aluminum nitride.Comprehensive analysis of the friction coefficient between SG polishing film and aluminum nitride and the scale of debris in the process,mechanical force play a leading role in the coarse polishing stage,hydration effect play a leading role in fine polishing stage.In the dry polishing process of SG polishing film,the film will crack,which will affect the sustainable processing performance of the film,while the wet polishing process of SG polishing film will not crack.Aluminum nitride will also hydrate with the deionized water in SG polishing film to form amorphous alumina compounds in the absence of additional deionized water.It is shown that the hydration water of the aluminum nitride substrate can be either from the binding water in SG polishing film or from the deionized water provided by the outside world.