自矽泥廢料中回收切割液之研究

Recovery of Glycol Solution from Silicon Slurry Waste

施郁霈(Yu-Pei Shih)

指導教授 ： 蔡子萱

國立臺北科技大學/工程學院/資源工程研究所/碩士(2011年)

摘要

於矽晶圓製造過程中，切割步驟造成了大量的廢棄物產生以及原料的浪費，龐大的矽泥廢料衍生出環境汙染問題，其中切割液即為最大宗的消耗品之一。隨著切割液價格日漸攀升，回收矽泥廢料中的切割液變得越來越重要。本研究以自矽泥廢料中回收切割液為目標，並考量回收技術的產業化需求，期能使回收的切割液重新用於矽晶棒的切割製程中。研究使用離心、沉降等方法進行矽泥廢料的固液分離處理，實驗發現升高溫度或提高廢料含無機溶劑（A）的量有助於沉降，並可回收獲得澄清液體，整體回收率為61%：但是若添加其他溶劑，儘管濃度相當，仍無法回收獲得澄清液體。以離心法進行固液分離時，相關的離心參數經由分析可知，5500 rpm轉速下，離心8hr或每次1 hr離心3次有較佳的離心分離效能；此外，利用離心前的震盪處理、加熱離心或降低進料黏度，均有助於離心法回收切割液。以離心法獲得透明澄清液體的回收率高達97%，時間較沉降法大幅縮短。
經固液分離後所回收獲得的液體需進一步純化才可重新用於切割製程中，本研究利用升高溫度改變切割液與溶劑A之間的作用，進而使溶解度發生變化來提純切割液，此方法不需使用減壓或汽化裝置，即可達到純化效果。最後，本論文針對回收提純後的切割液進行檢測，並與原始切割液比較，實驗結果顯示兩者間無論在基本物理性質、光譜、層析譜、質譜，以及對研磨砥粒的分散性能力上均相同，顯示利用本研究回收方法所獲得的切割液，無論就純度與品質來評估，均能使其重新用於矽晶棒的切割製程中。

關鍵字

矽泥廢料 ； 切割液 ； 回收 ； 分離 ； 純化

並列摘要

In silicon wafer manufacturing, a large amount of slurry waste is produced and feedstock is wasted during cutting process, resulting in environmental pollution and high cost. Recycling glycol solution is regarded as an important method to reduce the waste and cost. This study recovered glycol solution from the silicon slurry waste according to feasible industrial recycling technologies. The recovered glycol could be reuse in cutting process. We used gravity settling or centrifugation to separate liquid from the waste. The experimental results show that increasing temperature or A-solvent content of the waste can accelerate the separation by settling or centrifugation and produce a clear liquid layer. Its recovery yield reached 61% by gravity settling and 97% by centrifugation. However, adding other solvents could not produce clear glycol solution. The parameters of centrifugation were also studied, and it was found 5500 rpm for 8 hr-centrifugation or 3 times 1 hr-centrifugation resulted in good separation performance.
The collected liquid after settling or centrifugation should be purified to reuse in cutting process. This study reports the solubility of our glycol in the solvent A would decrease by increasing temperature. Therefore, heating the glycol-A solution would purify the glycol without the equipments for vacuum or the formation of vapor. Finally, the recovered glycol solution was examined and compared with the original one. The examination results show our recovered glycol solution are the same as the original one, and may be reuse to silicon cutting process.

並列關鍵字

Silicon Slurry Waste ； Glycol Solution ； Recovery ； Separation ； Purification

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