智能化對稱高速雙主軸研磨機開發與LED碳化鎢探針快速研削研究

Abstract

本研究旨在對LED電路偵測之碳化鎢探針的快速研磨成型，開發一部「智能化對稱高速雙主軸研磨機」。研究之初，先行開發「智能化對稱高速雙主軸研磨機」，並於系統上建構對稱高速雙主軸研削機構、線上線式放電削銳系統、線上研削力偵測與回饋系統、線上研削顫振偵測系統與線上次像素影像量測系統。對稱高速雙主軸搭載含硼聚晶鑽石磨輪，以啄式進給法(Peck feeding)，對LED碳化鎢探針進行徑向快速研削成型。為獲致高效率研削，本研究提出三項「智能化」研削策略，一為「線上研削力判斷回饋」，藉由三軸位移平台電流感知研削力大小，即時調整研削進給率；二為「研削系統振動偵測回饋」，利用位移平台的位置誤差偵測，將意外因素造成的系統振動，予以抑制，以維持穩定研削；三為「線上次像素影像量測」，透過線上CCD擷取成型探針的影像，以進行探針輪廓量測及可能的補償再加工，故探針無須拆卸，可提高研磨精度，並省卻繁複校正時間。鑽石磨輪採「多重電阻電容放電迴路」之「線上線式放電削銳」法進行削銳，多重電阻電容放電迴路能提供高尖峰值與窄脈衝寬度的高頻放電電流，故可降低鑽石磨輪的石墨化及鈷熔出。實驗證實，磨輪轉數30,000 rpm，並啟動智能化線上研削力判斷回饋機制時，研削效率能提升32%，探針完成時間約1.9分鐘，和人工研磨相比，可提高15倍以上的工作效率，探針表面粗糙度可達Ra 0.296µm；而含硼聚晶鑽石磨輪組之可磨探針數(平均壽命)為46支。本研究深具商業化價值。This study presents the development of an intellectualized symmetric high-speed dual-spindle grinding machine for LED probe made of tungsten carbide speedy grinding. First of all, an intellectualized symmetric high-speed dual-spindle grinding machine is designed. A set of symmetric high-speed dual-spindle, an in-situ Wire Electrical Discharge Dressing (WEDD) system, an in-situ Grinding Force Detection Feedback (GFDF) system, an in-situ Grinding Chattering Detection (GCD) system, and an in-situ Sub-Pixel Image Acquisition (SPIA) system are constructed on the grinding machine to achieve the intellectualization machining. The symmetric high-speed dual-spindle equips with a grinding wheel made of Boron-doped Polycrystalline Composite Diamond (BD-PCD) to speedy shaping the LED probe by symmetrically radial peck feeding grinding. Three strategies for intellectualization grinding are proposed in the study. The GFDF system, by which a grinding force is constantly detected from the stage current, gives real-time feedback to regulate the grinding feed-rate. By applying the in-situ GCD system, the position errors of stage is detected and suppressed to steady the grinding. The SPIA system provides for measuring the profile of LED probe on-machine, which achieves a high-precision on-line compensation and re-machining. The micro probe thus need not be unloaded and repositioned until all the planned tasks are completed, decrease tedious, time-consuming readjustment. Combining the in-situ WEDD system with the designed plural resistance-capacitances (pRC) relaxation circuit that can generate a current of high-frequency and high-peak with a short pulse train, the BD-PCD grinding wheels are precisely dressed on-machine, which reduces the amounts of cobalt precipitation and graphitizing of diamond. Experimental results demonstrate that the grinding performance can increase up to 32% when enabling the GFDF function under the grinding wheel’s rotation speed of 30,000 rpm. Comparing with manually made, the machining performance that the grinding time is about 1.9 minutes with a surface roughness of Ra 0.296μm for each probe can be enhanced up to 15 times when using the developed grinding machine tool. As a result, the tool life of the BD-PCD grinding wheel can be estimated at up to finish 46 pieces of LED probe. The developed technique provides a highly effective alternative for grinding hard-brittle, particularly LED probe made of tungsten carbide.