電鍍鑽石磨棒應用於玻璃基板磨削性能之研究

A Study on Grinding Performance with Elecroplated Diamond Coating Burs for Glass Substrate

紀啓偉(Chi-Wei Ji)

指導教授 ： 林盛勇

國立虎尾科技大學/工程學院/機械與電腦輔助工程系碩士班/碩士(2013年)

摘要

近年來，玻璃基板已逐步成為資訊產品產業發展的重要材料，其需求量不斷增加，對於它各種加工品質的要求也日益嚴苛。目前從事玻璃加工的產業大都以切割及磨削的方式為主，加工製程較為繁雜且成本也較高，所以尋求縮短製程及有效節省成本等方面的突破，乃當前加工技術之重要課題。由於玻璃具有高強度、高硬度及低導熱性等性質，在加工過程中刀具易產生快速磨損，加工表面易產生裂紋及邊緣崩角等缺陷。薄型玻璃夾持也不容易，必須使用真空吸盤以吸附的方式進行夾持。因此本文針對玻璃基板磨削性能與加工品質，結合高轉速、低磨削深度與不同的冷卻潤滑條件來進行一系列之探討。
本研究運用二種冷卻潤滑條件(水溶性切削劑、微量潤滑MQL)與電鑄鑽石磨棒觀察對於玻璃基板磨削性能的影響。於磨削實驗過程中使用真空吸盤以吸附方式夾持薄型玻璃基板，同時，利用動力計與頻譜分析儀監測玻璃基板之磨削力與振動量，再藉由工具顯微鏡觀察在不同磨削參數下的表面品質與邊緣破損，進行實驗結果分析與探討。結果顯示，水溶性切削劑提供磨削加工區的冷卻效果較佳，可有效減少玻璃邊緣破損並改善磨削表面品質，同時藉由沖洗可減少磨屑黏附於鑽石磨棒。微量潤滑提供磨削區域較好的潤滑效果，同時透過高壓空氣減少磨屑黏附的情形。磨削過程中發現有連續性切屑生成，證明玻璃基板磨削加工具有韌脆轉變之現象。綜觀整體磨削性能表現可得知，提高磨削速度與降低磨削深度可有效降低邊緣破損，減少不良率，獲得較佳的加工面品質。微量潤滑在磨削過程中容易產生高溫並形成熔融表面影響品質，此現象對於後續製程具有不良的影響。此兩種冷卻條件下若提高進給率容易使不良率增加，必須適當的調變參數藉以改善。

關鍵字

玻璃基板 ； 磨削 ； 韌脆轉變 ； 微霧潤滑

並列摘要

Glass substrate has gradually become the important material for information appliance industry application in recent years and its demand is increased constantly. Various requests on machining qualities of glass substrate are also more stringent. At present, the main machining ways on glass are almost with cutting and grinding and these machining processes are too complicated and too much wasted. Therefore, seeking a breakthrough for shortening the process and saving the cost effectively is an important issue for the machining workers. Because glass with high strength, high hardness and low thermal conductivity, it causes the cutting-tool wear quickly during the machining process. Also, the crack and edge-indentation are easily generated on the machined surface and outer edge. Furthermore, clamping thin glass substrate on jig platform is always a difficult issue until now. It has to be clamped by using vacuum chuck. Therefore a series of investigation about grinding performance and grinding quality under high grinding speed, low depth of cut and different cooling lubrication conditions is the topic of this study.
By using the electroplated diamond coating burs, the effects of two cooling/lubrication conditions (water-soluble cutting fluid and MQL) on grinding performance were investigated in this study. In the grinding experiment, vacuum chuck was used to absorb the thin glass substrate, dynamometer is used to monitor the variation of milling forces and torque, and accelerometer is used to measure vibration around the grinding zone. And tool wear, edge-indentation, chip morphology and surface morphology of the glass substrate were measured by tool-microscope off-line. The result shows that water-soluble cutting fluid provided better cooling effect at grinding area and it reduced edge crack and improved surface quality. At the same time, adhesion of cutting chips on electroplated diamond grinder was reduced by cutting fluid pouring. MQL lubrication provided relatively better lubrication effect at grinding area and its compressed air may also blow out the chips adhered on the electroplated diamond grinder at the same time. Continuous chips were found during the grinding processes, the phenomenon of ductile-brittle transition in the grinding of glass substrates removal is detected. A conclusion can be made based on the overall results of grinding performance, i.e. increasing grinding speed and reducing grinding depth can effectively reduce edge crack, lower defective rate, and better machined surface quality. Melting surface due to heat generation during the grinding process by using MQL has a bad effect on subsequent processing operation. If feed rate increases under both of the cooling conditions, defective rate increases likely and the other process parameters have to be properly adjusted for improvement of the defective rate.

並列關鍵字

glass substrate ； Grinding ； ductile-brittle transition ； MQL lubrication

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