• 전기전자학회논문지
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• 제22권3호
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• pp.874-877
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• 2018

인쇄 회로 기판(PCB: printed circuit board)에는 다수의 표면 실장 부품(SMD: surface mount device)이 장착되어 상호 연결되며, 이들을 연결하는 배선의 전송 특성이 나빠지면 시스템의 성능이 감소하게 된다. PCB와 SMD를 연결하는 패드는 PCB 전송 특성에 큰 영향을 미치기 때문에 패드의 위치도 최적화되어야 한다. 본 논문에서는 패드 정렬이 PCB 전송 특성에 미치는 영향을 시뮬레이션 하였다. 주파수가 비교적 낮은 경우에는 패드 정렬이 PCB 전송 특성에 큰 영향을 미치지 않지만 주파수가 높아지거나 패드 크기가 커질수록 패드 정렬에 따른 영향이 커진다. 따라서 목표 주파수와 패드 크기에 따라 세심하게 패드 정렬을 선택할 필요가 있다. 특히 12~18 GHz의 Ku-밴드 주파수 대역에서는 기존의 중앙 정렬 패드보다 제안하는 측면 정렬 패드가 전체적으로 유리하다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.171-175
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• 2001

Chemical mechanical polishing(CMP) process has been widely used to planarize dielectrics and metal, which can apply to employed in integrated circuits for sub-micron technology. Despite the increased use of CMP process, it is difficult to accomplish the global planarization of free-defects in inter level dielectrics and metal. Especially, defects like (micro-scratch) lead to severe circuit failure, and affects yield. Current conditioning method - bladder type, orbital pad motion- usually provides unsuitable pad profile during ex-situ conditioning near the end of pad life. Since much of the pad wear occurs by the mechanism of bladder type conditioning and its orbital motion without rotation, we need to implement new ex-situ conditioner which can prevent abnormal regional force on pad caused by bladder-type and also need to rotate the pad during conditioning. Another important study of ADPC is related to the orbital scratch of which source is assumed as diamond grit dropped from the strip during ex-situ conditioning. Scratch from diamond grit damaged wafer severely so usually scraped. Figure 1 shows the typical shape of scratch damaged from diamond. e suspected that intensive forces to the edge area of bladder type stripper accelerated the drop of Diamond grit during conditioning. so new designed Flat stripper was introduced.

• 대한기계학회논문집A
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• 제22권1호
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• pp.111-120
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• 1998

This paper is the first one of two-parted research efforts focusing on the modeling of rubber pad forming process. The rubber pad, driven by the pressurized fluid during the forming process, pushes the sheet metal to solid tool half and forms a part to final shape. In this part of the paper, a numerical procedure for the FE analysis of the rubber pad deformation is presented. The developed three-dimensional FE model is based on the total Lagrangian description of rubber maerial characterized by nearly incompressible hyper-elastic behavior under a large deformation assumption. Validity of the model as well as effects of different algorithms corresponding to incompresibility constraints and time integration methods on numerical solution responses are also demonstrated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.55-56
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• 2006

This research was carried out to observe the structure and characteristics of SUBA pad for silicon wafer polishing. As the diamond size is smaller and shape is rounder, the pad cut rate becomes smaller. From the experimental results, we suggests that the diamond grade should be over 680 when the diamond mesh is between #100 and #170 for SUBA pad.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1995년도 특별강연 및 추계학술발표 개요집
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• pp.145-148
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• 1995

To provide better understanding of a solder joint design criteria, mathematical models have been developed to calculate the shape of the solder fillets formed between the pad and lead. The effects of parameters such as solder volume and pad dimensions are described with this model. In this study, a systematic way to determine the design criteria of the SMT from the predicted 3D solder joint profile is proposed. The solder joint profile is calculated using the available 3D FEM code which minimizes the system energy due to the surface tension and gravity. The solder joint profiles of gullwing-type lead such as QFP and SOP are calculated for design parameters, and acceptable ranges are obtained. The result shows that the pad length is the most significant factor compared with the pad width and pad area.

• 한국의류학회지
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• 제41권5호
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• pp.939-949
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• 2017

This study uses 3D printing technology to design and fabricate a fall impact protection pad with a spacer fabric structure. The design of the pads consists of hexagonal three-dimensional units connected in a honey-comb shape; in addition, the unit consists of a surface layer and a spacer layer. Protect pads were designed as either a hexagonal type or diamond type according to the surface layer structure; subsequently, a spacer filament was also designed as the most basic I-shape type. Designed pads were printed using four types of flexible filaments to select suitable material for a fall impact protection pad. Impact protection performance and bending stiffness were evaluated for the eight type of pad outputs. As a result of the impact protection performance evaluation, when the force of 6,500N was applied, the force passed through the pad was in the range of 1,370-2,132N. FlexSolid$^{(R)}$ and Skinflex$^{TM}$ showed good protection performance and cubicon flexible filament showed the lowest protection. NinjaFlex$^{(R)}$ was found to be the most flexible in the bending stiffness evaluation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.569-570
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• 2006

The conditioning process is very important process for the CMP (Chemical Mechaning Polishing). This process regenerates the roughness of the polishing pad during the CMP process, increases the MRR (Material Removal Rate) and gives us longer pad life so conditioning process is essential for the CMP, and conditioning process influences the polishing pad shape gradually. Conditining process is related to the Non-Uniformity. In This paper, Kinematic of the conditioning process and mathematic modeling of the pad wear is studied and result shows how the various parameters influence the pad shape and WIWNU[1]. Consequently through these parameter, optimal design of the conditioning process equipment is predicted.

• 한국화재소방학회논문지
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• 제24권4호
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• pp.104-108
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• 2010

본 논문은 카본열선을 사용하는 전기장판에서 발생한 전기화재에 관하여 기술하였다. 카본열선을 사용하는 전기장판은 카본 재질의 특성상 전기용접이나 납땜 등의 방법으로 접속이 불가능하며, 열선 끝단을 카본 재질의 연결부를 만들어 접속해야 한다. 이러한 과정에서 열선 사이의 불완전 접속이 발생되며, 불완전 접속부에는 접촉저항의 증가로 국부적인 발열이 발생되고, 최종적으로 화재사고로 진전된다. 본 논문에서는 카본 열선 접속부에서 불완전 접속이 형성되는 경우, 접속부에서 전기적 발열에 의해 발생되는 열선의 손상 형태를 분석하여 화재원인을 규명하였다. 이러한 분석 결과는 카본 열선을 사용하는 전기장판의 화재원인 조사의 기초 자료로 활용 가능할 것으로 기대한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.563-564
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• 2006

Recently, CMP (Chemical Mechanical Polishing) is one of very important processing in semiconductor technology because of large integration and application of design role. CMP is a planarization process of wafer surface using the chemical and mechanical reactions. One of the most important components of the CMP system is the polishing pad. During the CMP process, the pad itself becomes smoother and glazing. Therefore it is necessary to have a pad conditioning process to refresh the pad surface, to remove slurry debris and to supply the fresh slurry on the surface. A diamond disk use during the pad conditioning. There are diamonds on the surface of diamond disk to remove slurry debris and to polish pad surface slightly, so density, shape and size of diamond are very important factors. In. this study, we characterized diamond disk with 9 kinds of sample.

• 마이크로전자및패키징학회지
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• 제22권3호
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• pp.51-56
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• 2015

솔더 조인트의 신뢰성 강화를 위해서 다양한 pad finish material이 사용되고 있으며, 최근에는 Electroless Ni Electroless Pd Immersion Gold (이하 ENEPIG) pad가 많이 사용되고 있다. 따라서, 본 연구는 상용화 되어 사용중인 Electrolytic Ni (soft Ni) pad와 최근 이슈가 되고 있는 ENEPIG pad에 대한 신뢰성 평가에 관한 것으로, 다양한 Cu 함량에 따른 거동을 관찰 하였다. Reflow 후 솔더와 pad간의 접합층은 $Cu_6Sn_5$에 Ni이 치환된 형태의 금속간 화합물로 구성되어 있었으며, ENEPIG pad의 경우, 접합층과 Ni layer 사이에 $Ni_3P$ (dark layer) layer가 관찰 되었다. 또한, Cu 함량에 따라 Dark layer의 두께를 제어할 수 있었다. 충격 낙하 시험 후, 파괴모드를 관찰한 결과 soft Ni pad와 ENEPIG pad에서 서로 다른 파괴모드가 관찰 되었으며, soft Ni의 경우, 1차 IMC와 2차 IMC 경계에서 파괴가 관찰 되었고, ENEPIG pad의 경우, dark layer에서 파괴가 관찰 되었다. IMC와 pad material, bulk 솔더와의 lattice mismatch에 의해 불안정한 계면이 존재하며, 이는 연속적인 외부 충격에 의해 가해진 열적, 물리적 스트레스를 IMC 계면으로 전송하기 때문에, 솔더의 신뢰성 향상을 위해서는 솔더 벌크의 제어와 IMC의 두께 및 형상의 제어는 필요하다.