Laser fracture milling and cutting techniques for thick ceramic substrate

• Main Authors: Chen,Hong-Wen, 陳鴻文
• Other Authors: Chwan-Huei Tsai
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/03165303817848860415

碩士 === 華梵大學 === 機電工程研究所 === 89 === A new laser machining technique for ceramic material based on the concept of fracture machining is proposed in this paper. The material removal is due to the crack propagation and the linkage of defects. The original concept of fracture machining comes from the laser cutting technique with controlled fracture for the brittle thin plate. The conventional laser machining requires high laser power and will result in many cracks during the grooving process. But the required laser power of the required laser power of the present method is much smaller than the traditional method. The finite element software ANSYS is used to analyze the temperature and stress distribution during the laser machining process. The experimental specimens are Al2O3 ceramic, and the laser sources are CO2 laser and Nd：YAG laser. The technique of edge machining for ceramic thick plate is investigated. The relationships of process parameters such as material removal rate, surface roughness, laser scanned speed, laser power, and feed speed of laser is also discussed. The fundamental models of material removal of strip material and fracture machining element are proposed. They can be applied on the edge milling and center blind-cavity milling for arbitrary shape. Finally, the two penetrated cutting methods for thick ceramic substrate are discussed. One is applying the CW focused Nd-YAG laser and the defocused CO2 laser at the same time to separate the ceramic substrate, in which the cutting depth can reach 10mm. The other is using Nd-YAG laser to scribe a groove-crack on a substrate, then applying the defocused CO2 laser at the back-side of the substrate to separate the material. Using this way to proceed more complicated curve cutting, the result of ceramic substrates are better than traditional method, not only on the rough status, but the crack faults, and so on, furthermore it decreases substantially the demands of laser power.