• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4757-4761
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• 2012

LED chip on board(COB) package has been fabricated using aluminum substrate and aluminum anodization process. An alumina layer, used as a dielectric in COB substrate, is produced on aluminum substrate by selective anodization process. Also, selective anodization process makes it possible to construct a thermal via with a fully-filled via hole. Two types of the COB package are fabricated in order to analyze the effects of their substrate types on thermal resistivity and luminous efficiency. The aluminum substrate with the thermal via shows more improved measurement results compared with the alumina substrate. These results demonstrate that selective anodization process and thermal via can increase heat dissipation of COB package in this work. In addition, it is proved experimentally that these parameters also can be enhanced using efficient layout of multiple chip in the COB package.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5117-5122
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• 2011

In this paper, thermal analysis simulation program by taking advantage of COMSOL Multiphysics, LED Module for the production of the most preferred package type, omitting the COH Type COB Type and board simulation of the thermal analysis is in progress. LED Module that passes through the Heat-sink of the simulation results, depending on the location of the COB Type Max. Approximately $78^{\circ}C$ ~ Min. Approximately $62^{\circ}C$, COH Type the Max. Approximately $88^{\circ}C$ ~ Min. Approximately $67^{\circ}C$ has been confirmed that the temperature stability. Compared with COB Type Max. AIthough temperature difference is about $10^{\circ}C$, Min. At a temperature of about $5^{\circ}C$ confirmed to be enough to reduce the gap, LED Point confirming the results of the temperature curves for COB Type Max. Approximately $100^{\circ}C$ ~ Min. Approximately $77^{\circ}C$, COH Type the Max. Approximately $100^{\circ}C$ ~ Min. Approximately $86^{\circ}C$ temperature stability was confirmed that, COB Type COH Type, compared to approximately $10^{\circ}C$ temperature was higher.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.158-163
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• 2013

In this paper, thermal analysis of heatsink for 30 W class Chip-on-Board (COB) LED light source is performed by using SolidWorks Flow Simulation package. In order to increase the convection heat transfer, number of fin and shape of the heatsink is optimized. Furthermore, a copper spread is applied between the COB LED light source and the heatsink to mitigate the heat concentration on the heatsink. With the copper spread, the junction temperature between the COB LED light source and the heatsink is $50.9^{\circ}C$, which is $5.4^{\circ}C$ lower than the heatsink without the copper spread. Due to the improvement of the junction temperature, the light output is improved by 5.8% when the LED light source is stabilized. The temperature difference between the simulation and measured result of the heatsink with the copper spread is within $2^{\circ}C$, which verifies the validity of the thermal design method using a simulation package.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.1-10
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• 2015

The light emitting diodes(LED) package of new structure is proposed to promote the reliability and lifespan by maximize heat dissipation occurred on the chip. We designed and fabricated the LED packages mixing the advantages of chip on board(COB) based on conventional metal printed circuit board(PCB) and the merits of Si sub-mount using base as a substrate. The proposed LED package samples were selected for the superior efficiency of the material through the sealant properties, chip characteristics, and phosphor properties evaluations. Reliability test was conducted the thermal shock test and flux rate according to the usage time at room temperature, high-temperature operation, high-temperature operation, high-temperature storage, low-temperature storage, high-temperature and high-humidity storage. Reliability test result, the average flux rate was maintained at 97.04% for each items. Thus, the Si sub-mount based LED package is expected to be applicable to high power down-light type LED light sources.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.799-800
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• 2012

• Journal of the Microelectronics and Packaging Society
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• v.16 no.3
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• pp.25-29
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• 2009

High temperature high humidity and thermal shock reliability tests were performed for the board level COB(chip-on-board) flip chip packages using self-formulated and commercial NCPs(non-conductive pastes) to ensure the performance of NCP flip chip packages. It was considered that the more smaller fused silica filler in prototype NCPs is more favorable for high temperature high humidity reliability. The failure of NCP interconnection was affected by the expansion of epoxy due to moisture absorption rather than the fatigue due to thermal stress. It was considered that the NCP having more higher adhesive strength seems to be more favorable to increase the thermal shock reliability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.158-158
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• 2008

모바일 정보통신기기를 중심으로 실장모듈의 초소형화, 고집적화로 인해 접속단자의 피치가 점점 미세화 됨에 따라 플립칩 본딩용 접착제에 함유되는 무기충전제인 실리카 필러의 크기도 미세화되고 있다. 본 연구에서는 NCP (non-conductive paste)의 실리카 필러의 크기가 COB(chip-on-board) 플립칩 패키지의 신뢰성에 미치는 영향을 조사하였다. 실험에 사용된 실리카 필러는 Fused silica 3 종과 Fumed silica 3종이며 response surface 실험계획법에 따라 혼합하여 최적의 혼합비를 정하였다. 테스트베드로 사용된 실리콘 다이는 투께 $700{\mu}m$, 면적 5.2$\times$7.2mm로 $50\times50{\mu}m$ 크기의 Au 도금범프를 $100{\mu}m$ 피치, peripheral 방식으로 형성시켰으며, 기판은 패드를 Sn으로 finish 하였다. 기판을 플라즈마 전처리 후 Panasonic FCB-3 플립칩 본더를 이용하여 플립칩 본딩을 수행하였다. 패키지의 신뢰성 평가를 위해 $-40^{\circ}C{\sim}80^{\circ}C$의 열충격시험과 $85^{\circ}C$/85%R.H.의 고온고습시험을 수행하였으며 Die shear를 통한 접합 강도와 4-point probe를 통한 접속저항을 측정하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.448-454
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• 2015

In this paper, the band structural design that is typically in a line was arranged in a ring shape, so as to configure the high power LED lighting in such a way as to form a concentrated light distribution angle of less than 15 degrees. The parabolic aluminized reflector PAR38 that facilitates design using area and the area of the optical system to the same extent, applied a multiple light-source condenser lens optical system for the control of integration. The LED used here implemented a single linear light source using ans LED module with ans LED, flip-chip chip-scale package. The optical system was designed based on the energy star standard.

• Journal of Sensor Science and Technology
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• v.27 no.1
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• pp.40-46
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• 2018

In this paper, we focus on optimization of a boron ($^{11}B$)-implanted n type Si epi substrate for obtaining near-zero temperature coefficient of resistance (TCR) at temperature range from 25 to $125^{\circ}C$. The $^{11}B$-implantation on the N type-Si epi substrate formed isolation from the rest of the N-type Si by the depletion region of a PN junction. The TCR increased as the temperature of rapid thermal anneal (RTA) was increased at the temperature range from $900^{\circ}C$ to $1000^{\circ}C$ for the $p^+$ contact with implantation at dose of $1E16/cm^2$, but sheet resistance of this film was decreased. After the optimization of anneal process condition, the TCR of $1126.7{\pm}30.3$ (ppm/K) was obtained for the $p^-$ resistor-COB package chips contained $p^+$ contact with the implantation of $5E14/cm^2$. This shows the potential of the $^{11}B$-implanted n type Si epi substrate as a resistor for pressure sensor in thermal stable environment applications..

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1609_1610
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• 2009

LED는 광학특성을 유지하기 위해서 최적의 방열설계가 요구된다. 이 논문에서는 입력FR-4의 Top Layer의 면적을 506.25[$mm^2$]이상으로 확대함으로써, 인가 전력 0.5W 조건하에서 FR-4 PCB로 MCPCB와 유사한 방열 특성을 발휘할 수 있음을 열화상카메라를 통한 측정 및 전산모사를 이용하여 확인하였다.