太陽能發電雖說是光電轉換的綠色產業,但是在製造過程中其實消耗了許多資源,近年來有相關文獻有提到以線切割放電加工作做矽晶圓的切割,利用放電切割的原理延伸至太陽能電池的晶邊絕緣,相較於目前使用之化學晶邊絕緣,省略了製程上所使用的化學藥液的使用及其廢液的處理,同時也減少了晶片邊緣的裂縫。 本文主要分兩大部分,第一是以純水為加工液,探討太陽能電池在完成磷擴散(P-type矽晶圓鍍上負極)製程後,以線切割放電加工作晶邊絕緣的製程,過程中,以加工電壓、加工速度作探討,並以高解析電子能譜儀檢測加工後的絕緣效果,第二則是觀察加工面的表面粗糙度,傳統的晶圓切片是利用琴綱線作切割,過程中所產生的加工應力會破壞晶片邊緣而產生裂縫,此種現象可利用放電加工改善琴鋼線加工的缺點,進而減少晶片邊緣裂縫。 實驗發現,利用線切割放電加工的負極切割方式,以每分鐘12cc以上的純水滴定量,電壓30V的條件下,可有效移除N層,且表面粗糙度由0.6µm降至0.365µm,即40%的改善效益,以每公升純水放電加工液添加0.6g的碳化矽,表面粗糙度可降至0.304µm,與純水當放電加工液比較有15%的改善效益。 ;Solar energy generation is a green industry, but it consumes a lot of resources in the manufacturing process. The literatures has mentioned to cut silicon wafers by using Wire EDM in recent years. Compared to the chemical insulation of the edge of silicon, the edge of silicon by using Wire cut Electrical Discharge Machining. It reduces chemical liquid of the manufacturing process and the cracks of wafer edge. This paper is divided into two parts . The first section is after the completion of phosphorus diffusion process of Solar cell, the pure water as processing liquid, the implementation of the edge of silicon by using Wire cut Electrical Discharge Machining (Negative plating on P-type silicon wafer).Machining voltage, processing speed as the machining parameters, and the high-resolution electron spectrometer is used to detect the insulating effect after processing. The second is to observe the surface of the machined surface roughness. The traditional wafer dicing using piano wire for cutting. Stress generated during processing of the wafer will destroy the edge of cracks. WEDM can improve the shortcomings of processing, Thereby reducing the edge cracks of wafer Experiments results show that used the negative electrode EDM cutting mode, upper titration of 12cc per minute and machining voltage,30V, the N layer can be removed effectively.
Surface roughness decreased from 0.6μm to 0.365μm. Improve efficiency of 40% achieved. Compared to the pure water, add 0.6g per liter of pure water silicon carbide as a Machining fluid, the surface roughness can be reduced to 0.304μm and 15% improvement efficiency. Keyword:Wire cut Electrical Discharge Machining、Polysilicon、Crystal edge insulation、Silicon carbide