Browsing by Author "Chin, JH"

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A comparative study on the roles of velocity in the material removal rate during chemical mechanical polishing
(1999-05-01)
Tseng, WT
;
Chin, JH
;
Kang, LC
;
機械工程學系
;
Department of Mechanical Engineering
Relative velocities between the flowing slurry and selected points on a 150 mm wafer and nonuniformity of velocity are calculated given the known carrier speed, platen speed, and pad-to-wafer distance. Based on simulation results, the combination of a high pad rpm, a medium wafer rpm, and a large pad-to-wafer distance should give rise to a minimum nonuniformity of velocity. Chemical mechanical polish (CMP) removal rates data are fitted to the original Preston equation, Tseng's model,(1) and a modified Preston equation which incorporates the deterioration characteristics of abrasives into the removal rate model. Theoretical removal rate data predicted by Tseng's model and the modified Preston equation exhibit much better agreement with experimental removal rates than those by the original Preston equation. The nonlinear dependence of removal rate on velocity can be explained by the deterioration in slurry abrasion capability. (C) 1999 The Electrochemical Society. S0013-4651(97)11-028-X. All rights reserved.
Cross-coupled precompensation method for the contouring accuracy of computer numerically controlled machine tools
(1997-07-01)
Chin, JH
;
Lin, TC
;
機械工程學系
;
Department of Mechanical Engineering
A cross-coupled precompensation method (CCPM) for precise trajectories of machine tools is proposed in this study. Compared with the conventional cross-coupled system and uncoupled system by computer simulation and experiment, the pure precompensation method is better in dealing with the circular trajectory and the elimination of the steady-state errors, while the CCPM can achieve the most precise tracking for both linear and circular trajectory at any feedrate. The advantages of CCPM will be enhanced at higher feedrates. At a feedrate of 200 mm/sec the CCPM stands out significantly. (C) 1997 Elsevier Science Ltd.
Cross-coupled precompensation method for the contouring accuracy of computer numerically controlled machine tools
(1997-07-01)
Chin, JH
;
Lin, TC
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
A cross-coupled precompensation method (CCPM) for precise trajectories of machine tools is proposed in this study. Compared with the conventional cross-coupled system and uncoupled system by computer simulation and experiment, the pure precompensation method is better in dealing with the circular trajectory and the elimination of the steady-state errors, while the CCPM can achieve the most precise tracking for both linear and circular trajectory at any feedrate. The advantages of CCPM will be enhanced at higher feedrates. At a feedrate of 200 mm/sec the CCPM stands out significantly. (C) 1997 Elsevier Science Ltd.
Effects of film stress on the chemical mechanical polishing process
(1999-11-01)
Tseng, WT
;
Wang, YH
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
A theoretical model is constructed to simulate the pressure distribution arising from wafer curvature (film stress) during chemical mechanical polishing (CMP), based on theories of elastic contact stress. Results from oxide CMP experiments suggest that the wafer curvature results in a nonuniform polish rate distribution across the wafer, in agreement with the simulation based on the model. This stress-dependent polish nonuniformity is attributed to the nonuniform pressure distribution across the wafer, induced by the wafer radius of curvature (film stress). Also, it was found that the magnitude of bride film stress itself has little effect on removal rate. Oxides with tensile stress tend to have a weakened bond structure and enhanced chemical reactivity, both of which result in slightly higher removal rates. The reverse is true for oxides with compressive stress. Deviations from the model prediction mag. result from the stress induced by slurry flow, local variations in wafer shape and form, and pad surface properties. (C) 1999 The Electrochemical Society. S0013-4651(99)03-063-3. All rights reserved.
Effects of support misalignments in deep-hole drill shafts on hole straightness
(2001-06-01)
Deng, CS
;
Huang, JC
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
This work investigates the effect of drill shaft support misalignment on hole straightness in relation to the various control factors. Misalignments occur in machine spindles, intermediate supports and pilot bushings. Equations for axial hole straightness deviation are derived herein using the Euler column theory, and experiments are performed using Gundrill and BTA deep-hole drilling systems. Simulation results, Sakuma's method and experimental examinations are also presented. Taguchi methods and statistical techniques are used to formulate the experimental layout, analyze the effect of each control factor on the results, and optimize the setting for each control factor. Further experiments then verify these estimates. Six control factors were used in a modified L8 orthogonal array design. The confirmatory experiments revealed an average straightness deviation within the 95% confidence interval. (C) 2001 Published by Elsevier Science Ltd.
Hole roundness in deep-hole drilling as analysed by Taguchi methods
(2005)
Deng, CS
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
This work investigates the roundness of holes by application of Taguchi methods to BTA deep-hole drilling with reference to process factors. Taguchi methods and statistical techniques are used in experimental layout, in the analysis of each control factor, and in prediction of the optimum setting for control factors. A set of confirmatory tests is then conducted to verify the estimated response. Influences of the control factors are discussed, and the levels of factors that produce holes of desired roundness with sufficient robustness are presented.
Improving contour accuracy by fuzzy-logic enhanced cross-coupled precompensation method
(2004-02-01)
Chin, JH
;
Cheng, YM
;
Lin, JH
;
機械工程學系
;
Department of Mechanical Engineering
Contour accuracy is obtained by efforts in algorithms. Most motion control algorithms reduce either position error or contour error to gain accuracy. In this paper, we investigate the idea of constructing a Fuzzy-logic controller to a proven algorithm, the cross-coupled precompensation method (CCPM), and using both position and contour error to generate compensation term. Simulation comparison with known methods and experimental comparisons among the uncoupled system, the cross-coupled system, the original CCPM and the proposed method were given. It was shown that the performance of the original CCPM was further enhanced. The proposed method also showed a better performance when subjected to external load. (C) 2003 Elsevier Ltd. All rights reserved.
Machining contour errors as ensembles of cutting, feeding and machine structure effects
(2003-08-01)
Cheng, YM
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
CNC machining has been studied from the perspective of either cutting or feeding. However, machining quality is the outcome of both of these processes. This work investigates the contour errors of a complete CNC machine system. A system model is developed to cover all groups of functions, including trajectory planning, trajectory tracking, cutting process and machine structure. Analysis results reveal the limitations of traditional studies. The dependence of contour errors on trajectory curvature, feed-rate, cutting depth and tracking control is investigated as well. A new model of CNC machining is developed. (C) 2003 Elsevier Science Ltd. All rights reserved.
Roundness, errors in BTA drilling and a model of waviness and lobing caused by resonant forced vibrations of its long drill shaft
(2004-08-01)
Deng, CS
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
The original purpose of this work was to propose an equation system to describe the kind of drilling in which the tools are with pronounced shaft length. The equation system turned out to disclose the low frequency mechanism of hole lobes. The proposed system is composed of Euler-Bernoulli beam equation representing tool shaft, and an excitation force in form of Fourier series. An empirical cutting force was established and related cutting force components were calculated. And the accumulated contribution of modes and harmonics was evaluated. The solution for the proposed equation system allowed a prediction of hole roundness which was consistent with experimental results for different conditions. The solution also allowed an investigation into the waviness and lobes. The results suggested that the bizarre phenomenon of lobes on hole is in reality waviness described by Tlusty for milling. The rigorous mathematical nature of the proposed equation built solid foundation for former empirical observation of waviness and lobes on workpieces.
System structure and contour tracking for a hybrid motion platform
(2005-11-01)
Lue, CW
;
Cheng, YM
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
This work investigates the spatial contour tracking on a new kind of motion platform that is constructed by extending the parallel platform with a proven planar motion table. Multi-axis cross-coupled tracking control schemes were developed on the basis of this hybrid structured Stewart platform, which formed a 5-axis working machine. A framework for the functions of this system was established. Roadmap for further development that leads to a highly versatile and efficient precision motion platform was made.
The algorithms of the cross-coupled precompensation method for generating the involute-type scrolls
(1999-03-01)
Chin, JH
;
Lin, HW
;
機械工程學系
;
Department of Mechanical Engineering
Cross-coupled precompensation method (CCPM) has been proven efficient in tracking nonlinear spatial curves. Ir requires a path generating algorithm derived from the mathematical equation of the target curve. This paper discussed the time base transform of target curve from a parametric form. The time based path generating algorithm for the extended involute scroll was then proposed. A comparison among three kinds of tool path generating algorithms were performed. The proposed path algorithms, along with other two algorithms, were implemented and tracked by Sour different control schemes. US (uncoupled-unprecompensated system), CCS (cross-coupled system), PPM (path precompensation method), and cross-coupled precompensation method (CCPM). The proposed path algorithm for extended involute scroll provided the best accuracy. The proposed algorithm tracked by CCPM achieved the most precise profile especially at high feedrates.
The path precompensation method for flexible arm robot
(1997-09-01)
Chin, JH
;
Lin, ST
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
This paper constructed a closed loop path precompensation method for a flexible arm robot. A torque computation method taking care of the elastic arm deformation was first proposed and discussed. A concept of partial deformation compensation was subsequently proposed to improve the torque profiles and the trajectory fidelity. The advantage of this concept was first shown by examples of planar trajectory. After the construction of the closed-loop path precompensation method for a flexible arm; the torque method and partial deformation compensation were incorporated to track the spatial trajectory. Numerical simulations were given to show the usefulness of the proposed concept and method. (C) 1997 Elsevier Science Ltd.
The path precompensation method for flexible arm robot
(1997-09-01)
Chin, JH
;
Lin, ST
;
機械工程學系
;
Department of Mechanical Engineering
This paper constructed a closed loop path precompensation method for a flexible arm robot. A torque computation method taking care of the elastic arm deformation was first proposed and discussed. A concept of partial deformation compensation was subsequently proposed to improve the torque profiles and the trajectory fidelity. The advantage of this concept was first shown by examples of planar trajectory. After the construction of the closed-loop path precompensation method for a flexible arm; the torque method and partial deformation compensation were incorporated to track the spatial trajectory. Numerical simulations were given to show the usefulness of the proposed concept and method. (C) 1997 Elsevier Science Ltd.
The shaft behavior of BTA deep hole drilling tool
(1996-05-01)
Chin, JH
;
Hsieh, CT
;
Lee, LW
;
交大名義發表
;
機械工程學系
This paper is a study on the shaft behavior of BTA deep hole drilling tool. The dynamics of tool shaft are often taken to be that of a second order lumped mass system for other cutting processes. This simplification does not apply for deep hole drilling because of its shaft length and the fact of fluid coupling. This paper constructed the general equations of motion for the pipe-like fluid conveying tool shaft of deep hole drill. The proposed general equations can be reduced to different specific forms of former works. Solutions for lateral and longitudinal motions were given. Series of experiments were designed and performed. Comparisons between theoretical and experimental results confirmed the validity of the constructed equations. The studies disclosed build the knowledge about the tool shaft and pave the way for future research concerning the correlation between the tool shaft and cutting process taking place on the cutting head.
The shaft behavior of BTA deep hole drilling tool
(1996-05-01)
Chin, JH
;
Hsieh, CT
;
Lee, LW
;
機械工程學系
;
Department of Mechanical Engineering
This paper is a study on the shaft behavior of BTA deep hole drilling tool. The dynamics of tool shaft are often taken to be that of a second order lumped mass system for other cutting processes. This simplification does not apply for deep hole drilling because of its shaft length and the fact of fluid coupling. This paper constructed the general equations of motion for the pipe-like fluid conveying tool shaft of deep hole drill. The proposed general equations can be reduced to different specific forms of former works. Solutions for lateral and longitudinal motions were given. Series of experiments were designed and performed. Comparisons between theoretical and experimental results confirmed the validity of the constructed equations. The studies disclosed build the knowledge about the tool shaft and pave the way for future research concerning the correlation between the tool shaft and cutting process taking place on the cutting head.
Theoretical and experimental investigations on the spinning BTA deep-hole drill shafts containing fluids and subject to axial forces
(1999-11-01)
Perng, YL
;
Chin, JH
;
機械工程學系
;
Department of Mechanical Engineering
The object of this investigation is to develop equations of motion and analyze the eigenproperties of spinning boring trepanning association (BTA) deep-hole drill shafts containing flowing fluid and subject to compressive axial force. The energy formulations are based on a coordinate system attached to the spinning shaft (floating coordinate system), and the equations of motion were derived using Hamilton's principle. This problem was studied for two different models: a Timoshenko beam model (which includes shear deformation, rotatory inertia moment, and gyroscopic moment effects) and a Euler-Bernoulli beam model. Galerkin's method was used to obtain solutions of the dynamic system. And two kinds of experimental test were performed to investigate the eigenproperties of spinning BTA deep-hole drill shafts: impulsive testing for non-spinning tool shafts, and random-input excitation testing for spinning tool shafts. Experimental results are also compared with simulation results. (C) 1999 Elsevier Science Ltd. All rights reserved.