Study On Preparation Of Superfine Diamond Superfinish Abrasive Tool

The rapid development of the integrated circuit(IC)industry requires that ultra-precision abrasive tools grind silicon wafers to achieve nano-level surface roughness.The preparation of super-precision grinding tools is a prerequisite for grinding silicon wafers.The current domestic diamond super-precision grinding tools have poor organizational structure and low porosity,which leads to problems such as excessive surface roughness of silicon wafers after grinding.In this paper,different diamond super-precision abrasive tools were prepared by temperature-controlled foaming method and gel injection molding combined with foaming method.Through the adjustment of the ceramic bond formulation,the temperature controlled foaming method was used to prepare a diamond superfine grinding tool with a porosity greater than 78%,a closed porosity accounting for about 90% of the porosity,and a good pore structure.Through optimization of process parameters,a diamond superfine grinding tool with apparent porosity of about 70% and complete pore structure is prepared by gel injection molding combined with foaming.In the preparation of diamond ultra-fine grinding tools by temperature-controlled foaming,the thermal stability of diamond was first examined from the aspect of particle size;then the low-temperature binder formula with excellent comprehensive performance was selected;and then the particle size,concentration and sintering system of diamond were studied.The effect of pore tissue structure was analyzed by scanning electron microscope and other instruments.Then the abrasive samples were characterized and analyzed by flexural strength and porosity.The experimental results show that the LR5 binder has the lowest sintering temperature,the sintering temperature range is 520 ±10 ?,and the flexural strength is 47.6 ~ 69.7 MPa in the sintering temperature range.When the temperature-controlled foaming sintering,the porosity of the LR5 binder sample The highest was 81.7%,and the pore structure of the binder sample performed best.At the same sintering temperature of 600 ?,the porosity of the diamond abrasive sample decreases as the diamond concentration and grain size increase.The porosity ranges from 67.8% to 78.9%.The flexural strength is 12.3 ~ 14.6 MPa.And the diamond superfine grinding tool has good pore distribution and microstructure.In the preparation of diamond ultra-fine grinding tools by gel injection molding and foaming method,the dispersibility of surface-treated and non-surface-treated diamonds in the gel was first investigated;optimizing the control parameters of high-quality slurry and gelation of abrasive tool samples;The effects of ceramic binder particles and monomer initiators on the porosity structure of the abrasive tool were studied;a suitable abrasive sample drying system was selected;and the determination of gel injection molding combined with foam diamond ultra-precision abrasive tools was determined sintering temperature,holding time and heating rate.The experimental results show that when the slurry temperature is around 25 ?,the ceramic binder particles are V200,and the monomer initiator concentration is 2.25 wt.%,The diamond superfine grinding tool has the highest porosity and good structure.In the abrasive sintering system,the sintering temperature is about 560 ?,the holding time is 1.5h,and the heating rate is 1 ? / min,the flexural strength of the abrasive sample is 20.4 ~ 24.6 MPa,and the porosity is 65.8% ~ 73.4%.