• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.273-279
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• 2016

This paper deals with a control system with a concentration sensor for Ni-W alloy plating solutions. The printed circuit board market has increased with the development of the electronics industry. Gold consumption has also increased dramatically. Various studies of composite plating solutions have been conducted because of the expense of gold. In comparison, the development of sensors capable of measuring a composite plating solution in real-time is still insufficient. Furthermore, there are few systems that can measure and control the concentration of the solution precisely. This study developed a sensor and system to control the concentration of composite plating solution accurately. The sensors were developed based on a spectrophotometric method and a feedback control method was applied in this system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.38-38
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• 2008

무선 통신에 사용되는 기판에서 passive device는 대부분 기판 위에 개별적으로 표면 실장 되고 있으며 전체 기판면적에 80% 정도를 차지하고 있다. 따라서 기판의 소형화, 경량화를 위하여 많은 면적을 차지하는 수동소자들을 다층인쇄회로기판(multi-layer circuit board)에 내장하는 내장형 수동소자(embedded passive device) 기술이 연구되고 있다. 본 연구원에서 개발한 복합재료는 무기물 충전제 $SrTiO_3$를 사용하였으며, 열가소성 수지로는 cyclo-olefin-polymer계열의 수지를 바탕으로 제작 하였고, 유전율7~7.5이고 유전손실은 0.0045이다. 또한 $SrTiO_3$/유기물 복합재료는 공정온도가 낮고 경제적인 유기물에 높은 유전상수를 갖는 무기물이 분산되어 있는 형태이며, 우수한 유전 특성, 화학적 안정성, 저온 제조공정, 제조단가의 감소, 패키징 크기의 감소 등의 장점을 갖는다. 개발된 재료를 기반으로 Multi-layer 구조를 이용한 다양한 용량대의 capacitor를 구현 하였으며, spiral inductor 와 내장형 spiral inductor를 구현하여 다양한 용량대의 inductor를 구현 하였다. 그리고 각각의 구조에 따른 inductance와 Q factor를 분석 하였으며, Q factor가 100이상인 high Q inductor도 구현하였다. 이렇게 구현된 내장형 수동소자는 기판의 크기의 감소와 제조 단가의 절감, 최소 크기의 기판을 구현하는데 응용이 가능 할 것으로 예상 된다.

• The Journal of the Korea Contents Association
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• v.6 no.6
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• pp.1-8
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• 2006

This paper presents an intelligent pattern matching method that can be used to acquire the reliable calibration data for automatic PCB pattern inspection. The inaccurate calibration data is often acquired by geometric pattern variations and selecting an inappropriate model manual. It makes low the confidence of inspection and also the inspection processing time has been delayed. In this paper, the geometric features of PCB patterns are utilized to calculate the accurate calibration data. An appropriate model is selected automatically based on the geometric features, and then the calibration data to be invariant to the geometric variations(translation, rotation, scaling) is calculated. The method can save the inspection time unnecessary by eliminating the need for manual model selection. As the result, it makes a fast, accurate and reliable inspection of PCB patterns.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.291-298
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• 2020

The power generation of a PV system changes according to the weather variables, such as solar radiation and temperature. In particular, the output characteristics of photovoltaic systems, which are sensitive to changes in solar radiation, can be produced effectively and reliably in various weather conditions through MPPT (Maximum Power Point Tracking) control. This paper proposes a fuzzy-based MPPT control method to improve the efficiency and stability of the power production from a solar system. To verify the performance of the proposed method, under the same weather environment, the efficiency and stability of the newly proposed fuzzy logic were compared and evaluated empirically with P&O (Perturb and Observe), a representative algorithm of MPPT control. Furthermore, the circuits designed to improve the reliability and reliability of the hardware were manufactured from Printed Circuit Boards (PCB) to conduct experiments. Based on the results of the experiment during a certain period, the fuzzy-based MPPT proposed in this paper improved the efficiency by more than 4.4% compared to the MPPT based on the existing P&O algorithm and decreased the fluctuation width by more than 39.7% at the maximum power point.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.30-30
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• 2018

스마트 도금공장을 구축하기 위해서는 도금액 내부의 화학 물질 농도 변화를 측정할 수 있는 화학 센서 기술이 필수적으로 요구된다. 와트욕은 대표적인 고속 니켈 도금액 중 하나로 기본적으로 황산니켈, 염화니켈, 보릭산의 염과 함께 케리어(type-1 광택제), 광택제(type 2-광택제), 응력 제어제 등의 유기 첨가제로 구성되어 있다. 이러한 유기 첨가제는 전차된 니켈층의 두께 균일도, 조도, 미세 구조, 내부 응력 등 다양한 특성을 제어하며, 정밀한 농도 관리가 필수적으로 요구되나, 분석 기술의 부재로 인하여 지금까지도 대부분의 액관리는 할셀법이나 작업자의 경험에 의존하고 있다. Cyclic voltammetry stripping(CVS) 방법은 전기화학 분석 과정에서 나타나는 첨가제의 가속, 감속 특성 등과 여기에 수반되는 stripping peak의 변화를 이용하여 개별 첨가제의 농도를 측정하는 방법이며, 지금까지 인쇄회로기판의 비아필 공정, 전해 동박 제조, 반도체 배선 등 구리도금 산업 전반에 걸쳐 첨가제 관리에 효과적으로 적용되고 있다. 그러나 수소 발생으로 인한 stripping 효율 문제로 인하여 니켈, 주석, 아연 등 표준 환원 전위가 높은 금속 도금액 내부 첨가제 농도 측정은 아직 어려운 상황이다. 본 연구에서는 이 문제를 극복하기 위해 염소를 과량 첨가한 구리 도금액을 CVS 분석의 base 용액으로 이용하여 니켈 도금액 내부 여러 광택제 (polyetylene glycol(PEG) 계열, thiourea 계열, 2-butyne-1,4-diol 등) 농도를 측정하는 법을 제시하였다. 제시된 방법은 CVS 분석 과정에서 구리-염소 사이의 상호 작용으로 인해 생성되는 3가지 stripping peak의 상대적인 크기 변화가 첨가제 농도에 따라 영향을 받는다는 사실에 기반하였다. 본 연구에서는 여기에 관한 원인에 대해 고찰하였으며, 제시된 방법을 통해 광택제 계열 첨가제 농도 측정을 선택적으로 할 수 있다는 것을 증명하였다.

• Progress in Medical Physics
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• v.26 no.2
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• pp.99-105
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• 2015

The monitor chamber is a real time dosimetry device for the measurement and the control of radiation beam intensity of the linac system. The monitor chamber prototype was developed for monitoring and controlling radiation beam from the linac based radiation generator. The thin flexible printed circuit boards were used for electrodes of the two independent plane-parallel ionization chambers to minimize the attenuation of radiation beam. The dosimetric characteristics, saturation and linearity of the measured charge, were experimentally evaluated with the Co-60 gamma rays. The performance of the developed monitor chamber prototype was in an acceptable range and this study shows the possibility of the further development of the chamber with additional functions.

• Resources Recycling
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• v.30 no.4
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• pp.3-10
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• 2021

The field of recycling for waste electronic components, which is the typical example of an urban mine, requires the development of useful sorting techniques. In this study, a sorter based on image identification by deep learning was developed to select electronic components into four groups. They were recovered from waste printed circuit boards and should be separated to depend on the difference after treatment. The sorter consists of a workstation with GPU, camera, belt conveyor, air compressor. A small piece (less than 3.5 cm) of electronic components on the belt conveyor (belt speed: 6 cm/s) was taken and learned as teaching data. The accuracy of the image identification was 96% as kinds and 99% as groups. The optimum condition of sorting was determined by evaluating accuracies of image identification and recovery rates by blowdown when changing the operating condition such as belt speed and blowdown time of compressed air. Under the optimum condition, the accuracy of image classification in groups was 98.7%. The sorting rate was more than 70%.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.1-12
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• 2023

In the current era of the global mobile smart device revolution, electronic devices are required in all spaces that people interact with. The establishment of the internet of things (IoT) among smart devices has been recognized as a crucial objective to advance towards creating a comfortable and sustainable future society. In-mold electronic (IME) processes have gained significant industrial significance due to their ability to utilize conventional high-volume methods, which involve printing functional inks on 2D substrates, thermoforming them into 3D shapes, and injection-molded, manufacturing low-cost, lightweight, and functional components or devices. In this article, we provide an overview of IME and its latest advances in application. We review biomimetic nanomaterials for constructing self-supporting biosensor electronic materials on the body, energy storage devices, self-powered devices, and bio-monitoring technology from the perspective of in-mold electronic devices. We anticipate that IME device technology will play a critical role in establishing a human-machine interface (HMI) by converging with the rapidly growing flexible printed electronics technology, which is an integral component of the fourth industrial revolution.

• Resources Recycling
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• v.27 no.5
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• pp.14-22
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• 2018

In this study, scarp of PCB containing copper and precious metals was manufactured as an anode, and electrorefining experiments were conducted on change of $H_2SO_4$ concentration and current density. Through electrolytic refining experiments, the concentration of Cu and slime recovered from each electrode was analyzed, element behavior was confirmed, and current efficiency was also calculated. As the $H_2SO_4$ concentration was increased, the current efficiency and the purity of Cu decreased, but the precious metals in the anode slime were maximally concentrated with 2.0 M $H_2SO_4$. In addition, as the current density was increased, the current efficiency decreased and the purity of Cu showed a tendency to increase, and the precious metals in the anode slime were maximally concentrated with $300A/m^2$. As a result of the pilot scale experiments, the Au content was 8,705 mg/kg, the Ag content was 35,092 mg/kg in the anode slime. As compared with the initial content, Au was concentrated 16 times and Ag concentrated 14 times.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.2
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• pp.71-76
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• 2019

Recently, the demand of labels for product management is increasing, as the automation system becomes more common. the development of functional labels which can be used in various environments has been rapidly proceeded. In the case of a printed circuit board, barcode labels with thermal and chemical stability are generally used due to a high temperature process around $300^{\circ}C$ and chemical cleaning in the manufacturing process. However, the yellowing phenomenon of labels that can lower the resolution of printed barcode image still needs to be prevented. In this study, we prepared a composite coating layer using a silica inorganic binder and a titanium dioxide white pigment, and developed a functional labels with thermal and chemical stability. The silica inorganic binder prepared by sol-gel process was confirmed to show excellent adhesion and abrasion resistance with the polyimide film. The white coating layer could be formed on the polyimide film with mixing the silica inorganic binder and titanium dioxide white pigment. The prepared coating layer showed excellent whiteness and glossiness above $400^{\circ}C$. The excellent chemical stability of the coating layer was also confirmed by the chemical treatment with acidic (pH 1.6) and basic (pH 13.6) cleaners.