• Journal of the Semiconductor & Display Technology
• /
• v.14 no.3
• /
• pp.57-60
• /
• 2015

Electric power in large devices is controlled by digital circuits, such as switching mode power supply. This kind of power circuits require accurate current sensor for power distribution. We studied characteristics of shunt resistor, which has many advantages for commercial application compared to Hall-effect current sensor. We applied ceramic package to the shunt resistor. Ceramic package has good thermal conductivity compared to plastic package, and this point is important for space requirement in Printed Circuit Board (PCB). Another advantage of the ceramic package is that surface mount technology (SMT) can be used for production. Our experimental results showed that the ceramic packaged resistor showed about 50% lower temperature than the plastic packaged one. Burning point and frequency characteristics are also discussed.

• Journal of electromagnetic engineering and science
• /
• v.6 no.1
• /
• pp.62-70
• /
• 2006

This paper presents a new power plane design method incorporating a single geometry derived from a unit cell of photonic bandgap(PBG) structure. This method yields constantly wide suppression of parallel plate resonances from 0.9 GHz to 4.2 GHz and is very efficient to eliminate PCB resonances in a specified frequency region to provide effective suppression of simultaneous switching noise(SSN). It is shown that with only two cells the propagation of unwanted high frequency signals is effectively suppressed, while it could provide continuous return signal path. The measured results agree very well with theoretically predicted ones, and confirm that proposed method is effective for reducing EMI, with measured near-field distribution. The proposed topology is suitable for design of high speed digital system.

• Journal of Applied Reliability
• /
• v.5 no.2
• /
• pp.261-272
• /
• 2005

In evaluation of electronic reliability on the PCB(Printed Circuit Board), electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs In the environment of the high humidity and the high temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water droll acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity of electrochemical migration depended on the temperature of water and the electrolyte quantity which included in the various waters.

• Proceedings of the Korean Reliability Society Conference
• /
• 2005.06a
• /
• pp.339-348
• /
• 2005

In evaluation of electronic reliability on the PCB(Printed Circuit Board),electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs In the environment of the high humidity and the high temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water drop acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity o of electrochemical migration depended on the temperature of water and the electrolyte quantity which included in the various waters.

• Journal of the Semiconductor & Display Technology
• /
• v.20 no.2
• /
• pp.126-130
• /
• 2021

The ball grid array is one of the packaging methods that used in high density printed circuit board. Solder void defects caused by voids in the solder ball during the BGA process do not directly affect the reliability of the product, but it may accelerate the aging of the device on the PCB layer or interface surface depending on its size or location. Void inspection is important because it is related in yields with products. The most important process in the optical inspection of solder void is the segmentation process of solder and void. However, there are several segmentation algorithms for the vision inspection, it is impossible to inspect all of images ideally. When X-Ray images with poor contrast and high level of noise become difficult to perform image processing for vision inspection in terms of software programming. This paper suggests the solution to deal with the suggested problem by means of using Mask R-CNN instead of digital image processing algorithm. Mask R-CNN model can be trained with images pre-processed to increase contrast or alleviate noises. With this process, it provides more efficient system about complex object segmentation than conventional system.

• Journal of Digital Convergence
• /
• v.18 no.11
• /
• pp.241-246
• /
• 2020

In this paper, we propose a neural network model to converge the marine electric propulsion system and deep learning algorithm to predict the DC/DC converter output current in the electric propulsion regeneration system and to predict the battery charge during regeneration. In order to experiment with the proposed neural network, the input voltage and current of the PCM were measured and the data set was secured on the prototype PCM board. In addition, in order to improve the learning results in the insufficient data set, the scale of the data set was increased through data fitting and its learning was executed further. After learning, the difference between the data prediction result of the neural network model and the actual measurement data was compared. The proposed neural network model effectively showed the prediction of battery charge according to changes in input voltage and current. In addition, by predicting the characteristic change of the analog circuit constituting the DC/DC converter through a neural network, it is determined that the characteristics of the analog circuit should be considered when designing the regeneration system.

• Journal of Internet Computing and Services
• /
• v.16 no.4
• /
• pp.61-70
• /
• 2015

This paper presents a web-based Java applet for understanding the concepts in digital logic circuits and student satisfaction survey was carried out in order to show its educational validity. Through our educational Java applet, the learners will be capable of learning the concepts and principles related to digital logic circuit experiments and how to operate virtual experimental equipments and virtual bread board. The proposed educational Java applet is composed of five important components: Principle Classroom to explain the concepts and principles for digital logic circuit operations, Simulation Classroom to provide a web-based simulator to the learners, Virtual Experiment Classroom to provide interactive Java applet about the syllabus of off-line laboratory class, Assessment Classroom, and Management System. With the aid of the Management System every classroom is organically tied together collaborating to achieve maximum learning efficiency. Finally, we have obtained several affirmative effects such as high learning standard, reducing the total experimental hours and the damage rate for experimental equipments.

• Journal of IKEEE
• /
• v.25 no.3
• /
• pp.485-492
• /
• 2021

In this paper, we propose the development of a defect inspection system for polygonal containers. Embedded board consists of main part, communication part, input/output part, etc. The main unit is a main arithmetic unit, and the operating system that drives the embedded board is ported to control input/output for external communication, sensors and control. The input/output unit converts the electrical signals of the sensors installed in the field into digital and transmits them to the main module and plays the role of controlling the external stepper motor. The communication unit performs a role of setting an image capturing camera trigger and driving setting of the control device. The input/output unit converts the electrical signals of the control switches and sensors into digital and transmits them to the main module. In the input circuit for receiving the pulse input related to the operation mode, etc., a photocoupler is designed for each input port in order to minimize the interference of external noise. In order to objectively evaluate the accuracy of the development of the proposed polygonal container defect inspection system, comparison with other machine vision inspection systems is required, but it is impossible because there is currently no machine vision inspection system for polygonal containers. Therefore, by measuring the operation timing with an oscilloscope, it was confirmed that waveforms such as Test Time, One Angle Pulse Value, One Pulse Time, Camera Trigger Pulse, and BLU brightness control were accurately output.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.279-282
• /
• 2002

In this paper, we present a new method for monitoring of ECU's self diagnostic signals of vehicle without wire. In order to measure the ECU's self diagnostic signals, the interfaced circuit is designed to communicate ECU and a designed display terminal according to the ISO, SAE regulation of communication protocol standard. A 80C196KC processor is used for communicating ECU's self diagnostic signals and the results are sent to PDA monitoring system. Software on PDA is developed to monitor the ECU's self diagnostic signals using the Embedded Visual C++ compiler in which RS232 port is programmed by half duplex method. The algorithms for measuring the ECU's self diagnostic signals are verified to monitor ECU's state. At the same time, the information to fix the vehicle's problem can be shown on the developed PDA software. The possibility for remote measurement of ECU self diagnostic signal using PDA is also verified through the developed systems and algorithms.

• Proceedings of the KIEE Conference
• /
• 2001.11c
• /
• pp.284-287
• /
• 2001

In this paper, we designed and implemented a precise pulse motor control chip that generates the parabolic speed pattern. This chip can control step motor[1], DC servo[2] and AC servo motors at high speed and precisely. It can reduce the mechanical vibration to the minimum at the change point of a degree of acceleration. Because the parabolic speed pattern has the continuous acceleration change. In this paper, we present the pulse generation algorithm and the parabolic pattern speed generation. We verify these algorithm using visual C++. We designed this chip with VHDL(Very High Speed Integrated Circuit Hardware Description Language) and executed a logic simulation and synthesis using Synopsys synthesis tool. We executed the pre-layout simulation and post-layout simulation with Verilog-XL simulation tool. This chip was produced with 100 pins, PQFP package by 0.35 um CMOS process and implemented by completely digital logic. We developed the hardware test board and test program using visual C++. We verify the performance of this chip by driving the servo motor and the function by GUI(Graphic User Interface) environment.