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Wu F.,Shantou University | Li S.,Shantou Institute for Light Industrial Equipment Research
Advanced Materials Research | Year: 2011

Pseudo solder is one kind of familiar solder joint defect, and it is very difficult to be detected in surface mounted technology. Reduce the pseudo solder is viewed as one of effectively way to keep the quality of solder joints. In this manuscript, the quality of component, solder paste printing process, mounting processing, reflowing process, solder material are analyzed to illustrate the cause of pseudo solder in surface mounted technology. Based on the five factors, a pseudo solder model is built for IC component. In the pseudo solder model, its parameters are used corresponding to the cause of pseudo solder, and their values are used to evaluate the degree of satisfaction based on the SMT technological process. Experiments results show that parameters of the pseudo solder model can illustrate the cause of pseudo solder effectively.

Cai L.G.,Beijing University of Technology | Feng Q.N.,Beijing University of Technology | Cheng Q.,Beijing University of Technology | Gu P.H.,Shantou Institute for Light Industrial Equipment Research | Zhang C.,Beijing University of Technology
Applied Mechanics and Materials | Year: 2013

The precision model of the 5-axis CNC machine tool can be built up based on the theory of kinematics for multi-body system (MBS). And then based on the precision model, the sensitivity analysis established with matrix differential is a method of identifying geometric error parameters for machine tool. And the geometric error factors of major parts that have relatively significant influence on comprehensive spatial error of the machine tool are identified. Finally, important theoretical basis for improving the titanium alloy Five-axis CNC machining center reasonably and for the error compensation can be provided. © (2013) Trans Tech Publications, Switzerland.

Cheng Q.,Beijing University of Technology | Zhang Z.,Beijing University of Technology | Zhang G.,Huazhong University of Science and Technology | Gu P.,Shantou Institute for Light Industrial Equipment Research | Cai L.,Beijing University of Technology
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2015

Machining accuracy of a machine tool is influenced by geometric errors produced by each part and component. Different errors have varying influence on the machining accuracy of a tool. The aim of this study is to optimize errors to get a desired performance for a numerical control machine tool. Applying multi-body system theory, a volumetric error model was constructed to track and compensate effects of errors during operation of the machine, and to relate the functional specifications on volumetric accuracy to the permissible errors on the joints and links of the machine. Error sensitivity analysis was used to identify the influence of different errors (especially the errors which have large influences) on volumetric error. Based on First Order and Second Moment theory, an error allocation approach was developed to optimize allocation of manufacturing and assembly tolerances along with specifying the operating conditions to determine the optimal level of these errors so that the cost of controlling them and the cost of failure to meet the specifications is minimized. The approach developed was implemented in software and an example of the geometric errors budgeting for a five-axis machine was discussed. It is identified that the different optimal standard deviations reflect the cost-weighted influences of the respective parameters in the equations of the functional requirements. This study suggests that it is possible to determine the coupling relationships between these errors and optimize the allowable error budgeting between these sources. © IMechE 2014.

Zhao Y.,Shantou University | Zhao Y.,Shanghai JiaoTong University | Zhao Y.,Shantou Institute for Light Industrial Equipment Research | Gao F.,Shanghai JiaoTong University | And 2 more authors.
Mechanism and Machine Theory | Year: 2010

This paper presents an elastodynamic characteristics comparison of the 8-PSS redundant parallel manipulator and its non-redundant counterpart-the 6-PSS parallel manipulator through simulation. The natural frequency and the displacement response of the moving platform are investigated, respectively. It is shown that the natural frequency of the 8-PSS redundant parallel manipulator is higher than that of the 6-PSS parallel manipulator while its displacement responses of the moving platform are smaller than those of the 6-PSS parallel manipulator. © 2009 Elsevier Ltd. All rights reserved.

Chen S.,Shantou University | Chen S.,Shantou Institute for Light Industrial Equipment Research
Advanced Materials Research | Year: 2011

The paper presents a method of the serial communication codes of the testing interface card by using the serial monitor software and ROBO Pro graphical software, and the research on the movement control system is based on Fischertechnik interface. The system software with Windows style is developed by using the serial communication function of advanced programming language VB6.0. The serial interface program through the MSComm control of VB6.0, and the status of Fischertechink interface could be detected through the received communication codes, sending communication codes to control the movement of mode.

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