Experimental Research On Sapphire Wafer Quality And Cutting Force In Multi-wire Swing Reciprocating Wire Saw Cutting

With the development of the LED lighting industry,the processing efficiency and processing requirements for sapphire substrates are also increasing.Cutting is the first process in the production of sapphire,and the processing quality of the substrate has an important influence on a series of processing techniques such as subsequent grinding and polishing.Multi-line swing reciprocating cutting equipment is currently the most widely used processing equipment for cutting and processing sapphire,but the current research on the processing quality and sawing force in the sawing process is still insufficient.This paper focuses on the research on the sawing force during the cutting process of sapphire by the multi-line swing reciprocating wire saw and the surface quality of the substrate after processing.Through the ingeniously designed segmented force measurement method,the change law of sawing force at different positions of the wire web was tracked and detected;the influence law of the processing parameters on the sawing force was studied;a new method of wire-cut wafer surface quality was proposed.Evaluation index: minimum machining allowance(MMA)of wire slicing;comparative study of the influence of processing parameters on wire saw slicing quality;analysis of the relationship between sawing force and wafer processing quality at different positions of the wire web.The main research results of the thesis are as follows:1.Propose a new evaluation method for the processing quality of wire slicing: the minimum machining allowance MMA;the related program for calculating MMA is developed on the platform of the laser thickness gauge to realize the evaluation of the processing quality of the wire slicing.2.In the sapphire crystal bar wire saw processing,the sawing force Fz brought by the swing motion during the processing is the largest in the middle of the online network,while the supply end and take-up end of the online network are smaller;due to the reciprocation of the wire saw The sawing force Fy is the smallest in the middle of the online network,while the online supply end and the online take-up end are larger.The swing angle has the greatest impact on the sawing force Fz,and the total wire consumption and changes in the swing angle have a greater impact on the sawing force Fy.3.From the wire network supply end to the take-up end,the thickness of the chip gradually increases and then tends to stabilize at the take-up end;the total thickness deviation of the chip is larger at the take-up end of the TTV online network,while the middle position of the online network and the supply end are Small;the warp of the wafer decreases first and then increases from the wire supply end to the take-up end;the warp of the wafer gradually decreases from the wire network supply end to the takeup end,and the wafer warp MA gradually increases from the supply end to the take-up end,and the increase trend is greater at the supply end,and slowly increases at the intermediate position and the take-up end.The MMA of the chip decreases first and then increases from the wire network supply end to the wire network take-up end.4.In the cutting process,using a larger total wire consumption,total cutting time,swing angle and tension force can obtain a better total wafer thickness deviation TTV.Using larger total wire consumption,swing angle and smaller total cutting time and tension force can obtain better wafer bow.The total wire consumption,total cutting time,line speed and tension have little effect on the warp of the wafer;however,the greater the swing angle,the smaller the warp of the wafer.The MA of the wafer changes greatly with the change of the process parameters.The MMA of the wafer varies little with the change of process parameters,but the swing angle has the greatest impact on the MMA of the wafer.5.The change of the sawing force has a good corresponding relationship with the change of the surface quality of the wafer after the cutting process.