• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.120-128
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• 2004

The impulse between launch vehicle and atmosphere can generate a lot of noise and vibration during the process of launching a satellite. Structurally, the electronic equipment of a satellite consists of an aluminum case containing PCB. Each PCB has resistors and IC. Noise and vibration of the wide frequency band are transferred to the inside of fairing, subsequently creating vibration of the electronic equipment of the satellite. In this situation, random vibration can cause malfunctioning of the electronic equipment of the device. Furthermore, when the frequency of random vibration meets with natural frequency of PCB, fatigue fracture may occur in the part of solder joint. The launching environment, thus, needs to be carefully considered when designing the electronic equipment of a satellite. In general, the safety of the electronic equipment is supposed to be related to the natural frequency, shapes of mode and dynamic deflection of PCB in the electronic equipment. Structural vibration analysis of PCB and its electronic components can be performed using either FEM or vibration test. In this study, the natural frequency and dynamic deflection of PCB are measured by FEM, and the safety of the electronic components of PCB is evaluated according to the results. This study presents a unique method for finite element modeling and analysis of PCB and its electronic components. The results of FEA are verified by vibration test. The method proposed herein may be applicable to various designs ranging from the electronic equipments of a satellite to home electronics.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.5-11
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• 2003

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.64-69
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• 2018

Automatic test equipment for field maintenance of aircraft mounted equipment is effective for integrated design when operating a small number of aircraft for special purposes. The integrated automatic test equipment identifies commonly used interfaces and is used for branching or generating routes for each unit under test specific inspection. High-precision signals such as RTD, TC, and analog voltage can cause measurement errors due to conduction resistance during signal branching and connection when generating branches and paths. The measurement error caused by the resistance of the wire leads to a lot of restrictions in designing the equipment to be inspected. In this paper, we propose a method of calibrating highly accurate signals of an integrated automatic inspection equipment that minimizes measurement errors of analog voltage and high - precision signals.

• Journal of KSNVE
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• v.6 no.3
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• pp.363-373
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• 1996

In the case of a precision equipment, it requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga class semiconductor wafers. This high technology equipments require very strict environmental vibration standard in promotion to the accuracy of the manufacturing, inspecting devices. The vibration criteria are usually obtained either by the real vibration exciting test on the equipment or by the analytical calculation. The former is accurate but requires a great deal of time and efforts while the latter lacks reliability. This paper proposes a new method to solve this problem at a time. The permissible vibration level to a precision equipment can be easily obtained by analyzing the process of Frequency Response Function(FRF). This paper also demonstrates its effectiveness by applying the proposed method to finding the permissible vibration criteria of a Computer Hard Disk Drive.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.5
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• pp.486-492
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• 2013

Energy cost has been increasing rapidly to comply with environmental regulations worldwide and the manufacturing industry who consumes more than half of the total energy needs to improve their cost competitiveness considering environmental costs. Machine tools are essential elements in manufacturing industry and efforts have been made recently to increase their energy efficiency mainly by German and Japanese machine tool builders. In this paper, trends in energy saving technology are described on the hardware and software sides of peripheral equipment of machine tools. In addition, the power consumption of a machining center is measured and analyzed to develop a software-based standby strategy for energy saving with peripheral equipment of machine tools.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.4
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• pp.15-21
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• 1997

Pneumatics is widly used in the industrial implementation, in the operation of air-powered actuators and the control devices needed in their operation. However, there are many empirical factors in pneumatics design, it might cause excessive design of pneumatic components. For that reason, we developed VDES(Vacuum Design Expert System) for the economic design of pneumatic vacuum equipment. VDES is achieved with CLIPS(C Language Integrated Production System) and knowledge base that contains a number of facts and rules for pneumatic vacuum design. Forward chaining and depth first search technique are used in this system. Appling VDES to the actual field, this system is verified to be a good efficiency and could be applied to the field of pneumatic vacuum equipment design.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.39-39
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• 2003

As the design rules in semiconductor manufacturing process become more and more stringent, the higher degree of planarization of device surface is required for a following lithography process. Also, it is great challenge for chemical mechanical polishing to achieve global planarization of 12” wafer or beyond. To meet such requirements, it is essential to understand the CMP equipment and process itself. In this paper, authors suggest the velocity distribution on the wafer, direction of friction force and the uniformity of velocity distribution of conventional rotary CMP equipment in an analytical method for an intuitive understanding of variation of kinematic variables. To this end, a novel dimensionless variable defined as “kinematic number” is derived. Also, it is shown that the kinematic number could consistently express the velocity distribution and other kinematic characteristics of rotary CMP equipment.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.29-38
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• 2003

As the design rules in semiconductor manufacturing process become more and more stringent, the higher degree of planarization of device surface is required for a following lithography process. Also, it is great challenge for chemical mechanical polishing to achieve global planarization of 12” wafer or beyond. To meet such requirements, it is essential to understand the CMP equipment and process itself. In this paper, authors suggest the velocity distribution on the wafer, direction of friction force and the uniformity of velocity distribution of conventional rotary CMP equipment in an analytical method for an intuitive understanding of variation of kinematic variables. To this end, a novel dimensionless variable defined as “kinematic number” is derived. Also, it is shown that the kinematic number could consistently express the velocity distribution and other kinematic characteristics of rotary CMP equipment.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.12 s.189
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• pp.64-71
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• 2006

In this study, to design aluminum scrap recycling equipment, fluid flow and thermal analysis considering electromagnetic phenomenon were carried out by using ANSYS program. The magnetic flux generated by electromagnetic pump has influence on fluid velocity of Al liquid metal with molten metal motion and thermal generation. To investigate the effect of the number of phase on fluid flow and thermal generation, electromagnetic force and magnetic flux were obtained by computer simulation. In addition, the results obtained by fluid flow and thermal analysis, recycling equipment of aluminum scrap with the cooling technology of electromagnetic coil, the most suitable phase and current were proposed.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.2
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• pp.56-59
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• 2006

A vibrational model of powder transfer equipment based on the lumped parameter method was developed, in which the operating motion consists of surging, bouncing, and pitching. After decoupling the equation of motion, the vibrational excitation source of the pitching motion was removed. So the designers are able to plan the optimum design to adjust the motion trajectory of the powder transfer equipment. That is, a procedure to adjust the motion trajectory of powder transfer equipment by changing design specifications such as the installation position, the direction of the motor, the driving speed, the mass unbalance, the stiffness coefficient, and the installation position of the support spring, is presented in this paper. The powder transfer equipment manufactured according to the results of this study did not suffer fatigue destruction, since the maximum stress on the basket structure was sufficiently small.