Analysis on Temperature Field Simulation for Offset Cutting a Nanochannel at a Fixed Down Force on Single-crystal Silicon Using Three-dimensional Quasi-steady Molecular Statics Nanocutting Model

分子靜力學三維準穩態奈米切削模式模擬固定下壓力偏移加工單晶矽奈米流道凹槽之溫度模擬分析

林榮慶(Zone-Ching Lin) ； 胡育政(Yu-Jheng Hu) ； 趙柏棠(Bo-Tang Zhao)

《中國機械工程學刊》 40卷5期 (2019/10) Pp. 439-448

摘要

The paper develops three-dimensional quasi-steady molecular statics nanocutting model to simulate offset cutting a nanochannel trapezium groove on single-crystal silicon at a fixed down force by a small probe. It is set that after a cutting pass is performed at a fixed down force on each cutting layer, the probe offsets rightwards to perform one more cutting pass, and then offsets leftwards to the middle position between the two passes aforesaid to perform cutting - this process is regarded as an offset cutting. The down force and cutting force of each cutting pass on the first cutting layer obtained from simulation of three-dimensional quasi-steady molecular statics nanocutting model are compared with the down force and cutting force of the cutting pass on the first cutting layer obtained from SDFE theoretical equation. The comparison has proved that it is feasible to use the three-dimensional quasi-steady molecular statics nanocutting model developed by the paper to simulate offset cutting of nanochannel trapezium groove at a fixed down force on single-crystal silicon by a small probe. The paper considers that plastic heat and friction heat would be produced during cutting of every cutting pass. The plastic deformation heat of the paper can be calculated by multiplying the equivalent stress and equivalent strain of the workpiece of single-crystal silicon being cut. Focusing on the production method of friction heat on the surface of cutting tool for nanocutting of single-crystal silicon, the paper finds the calculation method of temperature rise produced from friction heat. After finding the sum of temperature rise produced from two heat sources, the paper achieves the total temperature rise of each atom of the single-crystal silicon workpiece being cut, and then analyzes the temperature field of each cutting pass on the first cutting layer when performing offset cutting at a fixed cutting force.

關鍵字

molecular statics ； offset cutting ； nanochannel ； specific down force energy ； temperature field

並列摘要

本文發展出分子靜力學三維準穩態奈米切削模式，模擬AFM探針切削單晶矽奈米流道梯形凹槽的固定下壓力偏移加工。本文以固定下壓力之偏移循環加工方法，加工單晶矽基板奈米流道梯形凹槽，其為設定每切削層在固定下壓力下切削一道次，然後將探針向右偏移再切削一道次，再將探針向左往回偏移至前述兩道次中間位置切削加工，做為一個偏移加工。本文再用分子靜力學三維準穩態奈米切削模式模擬比下壓能理論採用的切削深度，模擬所得之第一切削層各切削道次之下壓力及切削力和用比下壓能理論之公式所得之第一切削層切削道次之下壓力及切削力相比較，驗證本文發展的分子靜力學三維準穩態奈米切削模式模擬AFM探針切削單晶矽奈米流道梯形凹槽的固定下壓力偏移加工為合理可行。本文考慮各切削道次加工時，會產生塑性熱及摩擦熱。本文塑性變形熱可由被切削工件單晶矽，其等效應力與等效應變之乘積計算出。本文針對奈米切削單晶矽刀面上產生摩擦熱的方法，並計算因摩擦熱源產生的溫度提升之方法。本文再將兩種熱源所產生之溫度提升加總計算後，得到被切削單晶矽工件各原子提升之總溫度，再進行固定下壓力偏移加工的第一切削層各切削道次的溫度場分析。