Study On The Mechanism Of Cemented Carbide Chemical Mechanical Polishing Considering Workpiece-Abrasive-Pad Contact State

Chemical mechanical polishing?CMP?,as one of the main technical means for global flattening of processing surfaces at the present stage,this technology is initially mainly applied to the surface processing of integrated circuit interconnect chips.Due to the excellent performance of the surface after CMP processing,this technology is also increasingly used in the processing of brittle and hard metal surfaces.Different workpieces have different material properties and their processing mechanisms are also different.Many scholars have studied the CMP mechanism from all sides,but at this stage,the understanding of the CMP mechanism of cemented carbide materials is still in its infancy.This article takes YG8 cemented carbide insert as the research object,considers the contact state between workpiece-abrasive-polishing pad from the micro level,and studies the material removal mechanism of cemented carbide CMP.main tasks as follows:?1?Experimentally studied the effects of chemical action,mechanical action,and chemical mechanical synergy on the material removal rate and surface quality of YG8cemented carbide insert in the CMP processing system.The experimental results show that the removal rate of materials produced by simple chemical and mechanical actions is small,and most of the materials are removed by the synergistic effect of chemical and mechanical actions.The main form of material removal on the blade surface is abrasive friction and wear.When the mechanical wear strength is too large or the chemical corrosion effect is too strong,the surface damage of the blade after polishing is more serious;when the mechanical wear strength of the abrasive and the polishing pad is balanced with the chemical corrosion strength of the chemical agent,the polishing effect is best.?2?Considering the different contact states of workpiece-abrasive-polishing pad,the material removal rate model of cemented carbide CMP is established.For the three different contact states of non-contact,partial contact and complete contact between workpiece-abrasive-polishing pad,based on the elastoplastic contact mechanics and mathematical statistical theory,the depth of single abrasive embedded in the surface of the workpiece and the effective abrasive involved in processing is studied.The material removal rate model of cemented carbide CMP is established.The stress conditions of single abrasive in the critical state of non-contact and partial contact,partial contact and full contact are analyzed,and the critical conditions of non-contact and partial contact,partial contact and full contact are obtained.?3?It reveals the influence of abrasive particle size D,polishing load F,abrasive concentration C and polishing speed V on the CMP processing effect and contact state of YG8 cemented carbide.The research results show that:under the three contact states,the polishing speed V is proportional to the material removal rate R,and the abrasive particle size D has little effect on the material removal rate R.In the non-contact and full contact state,the material removal rate R is proportional to polishing load F^7/6;in the partial contact state,the material removal rate R is proportional to polishing load F^3/2.In the non-contact state,the material removal rate R is proportional to abrasive concentration C^1/2;in the partial contact and full contact state,the material removal rate R is proportional to abrasive concentration C.