Ultra Precision Grinding of Wafer Scale

2012 ◽  
Vol 516 ◽  
pp. 257-262
Author(s):  
Martin Hünten ◽  
Fritz Klocke ◽  
Olaf Dambon ◽  
Benjamin Bulla

Manufacturing moulds for the wafer-scale replication of precision glass optics sets new demands in terms of grinding tool lifetime and the processes to be applied. This paper will present different approaches to grinding processes and kinematics to machine wafer-scale tungsten carbide moulds with diameters of up to 100 mm and more than 100 single aspheric cavities, each featuring form accuracies in the micron range. The development of these processes will be described and advantages and disadvantages of the approaches derived from practical tests performed on an ultra precision grinding machine (Moore Nanotech 350FG) will be discussed. Finally, a comparison between the developed processes is made where achieved form accuracies and surface topography are analyzed.

2020 ◽  
Vol 10 (6) ◽  
pp. 2030
Author(s):  
Lai Hu ◽  
Yipeng Li ◽  
Jun Zha ◽  
Yaolong Chen

In the global machining industry, ultra-precision/ultra-high-speed machining has become a challenge, and its requirements are getting higher and higher. The challenge of precision grinding lies in the difficulty in ensuring the various dimensions and geometric accuracy of the final machined parts. This paper mainly uses the theory of a multi-body system to propose a “double accuracy” theory of manufacturing and measurement. Firstly, the grinding theory with an accuracy of 0.1 μm and the precision three-coordinate measuring machine theory with an accuracy of 0.3 μm are deduced. Secondly, the two theories are analyzed. Aiming to better explain the practicability of the “double accuracy” theory, a batch of motorized spindle parts is processed by a grinding machine. Then the precision three-coordinate measuring machine is used to measure the shape and position tolerances such as the roundness, the squareness, the flatness, and the coaxiality. The results show that the reached roundness of part A and B is 5 μm and 0.5 μm, the squareness is 3 μm and 4.5 μm, and the coaxiality tolerance is 1.2 μm, respectively.


2013 ◽  
Vol 336-338 ◽  
pp. 1014-1019
Author(s):  
Seon Yeol Oh ◽  
Han Seok Bang ◽  
B. Y. Choi ◽  
Woo Chun Choi ◽  
S. J. Cho

A finite element model of an ultra-precision grinding machine that can have high precision and high stiffness is constructed and structural analysis is done with equivalent stiffnesses of linear motion guides by after structural design and the deformation of the grinding machine is obtained. In order to reduce the deformation of the grinding machine that causes bad influence, structural complement is conducted by adding ribs at the lower part of the column. Also, the straightness of the grinding machine is improved by lifting that the base side of the column.


Author(s):  
Xun Chen ◽  
Michael N. Morgan

This paper reviews grinding research led by Professor W Brian Rowe at Liverpool John Moores University and at other establishments previously. Research reviewed extends over fundamentals of grinding processes and machine performance carried out over fifty-five years. Topics range from accuracy in centreless grinding and other grinding processes to grinding machine behaviour and high precision grinding machine design including bearing technology. Research also ranges to high-removal rate grinding processes, surface integrity and intelligent process control. This review highlights progress in selected areas and demonstrates that improving product quality allows improved manufacturing productivity.


2012 ◽  
Vol 566 ◽  
pp. 530-533
Author(s):  
Zhi Hua Sha ◽  
Shao Xing Zhang ◽  
Yi Wang ◽  
Sheng Fang Zhang

Mono-crystalline silicon is the typical substrate material in integrated circuits manufacturing, and machining precision and surface quality of the silicon wafer impacts on the quality and performance of the electronic products directly. Silicon grinding technology has high accuracy, low cost and can obtained high surface quality, which has become the mainstream of silicon ultra-precision machining. Stick-slip of feeding system in silicon ultra-precision grinding machine is an important factor which influencing the machining precision of the silicon wafer. In this paper, based on the structure analysis of feeding system in a certain type of silicon ultra-precision grinding machine, the rigid body coupling virtual prototype model of the feeding system is established using ADAMS, the factors which influencing the stick-slip is analyzed deeply via the dynamic simulation of the virtual prototype.


2007 ◽  
Vol 359-360 ◽  
pp. 523-527 ◽  
Author(s):  
Ming Jun Chen ◽  
Qi Long Pang ◽  
Jing He Wang ◽  
Kai Cheng

3Dfractal dimension and 2D profile fractal dimension distribution of the surfaces made by brittle or ductile grinding are calculated. From the calculated results of 3D fractal dimension, it can be found that the microtopograhpy of ductile ground surface is more exquisite than brittle ground surface and 3D fractal dimension Ds has inverse relation with the roughness parameter Rq. Through the analysis of 2D profile fractal dimension distribution in different ground surfaces, it is revealed that the topography of ground surface is changed with grinding parameters such as ground surfaces may have weakly or strongly anisotropic even isotropic features when different grinding parameters are adopted. Using fractal method to analyze the topography of ground surface is helpful to understand the generating mechanism of surface topography.


2014 ◽  
Vol 625 ◽  
pp. 587-592 ◽  
Author(s):  
Benjamin Bulla ◽  
Fritz Klocke ◽  
Olaf Dambon

For the production of mould inserts for precision glass moulding, the ultra precision grinding technique with a subsequent manual polishing operation is typically applied. These processes are time consuming and have a relatively low reproducibility. An alternative manufacturing technology, with a high predictability and efficiency, which additionally allows a higher geometrical flexibility, is the diamond turning technique. In addition the ultrasonic assisted ultra precision cutting process has already proven its potential for machining difficult-to-cut materials, such as steel and glass. By applying the ultrasonic assistance, the classic constraints of the process can be widened significantly. In this publication the process is applied on binderless, nanocrystalline tungsten carbide.


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