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Wetting Balance Test를 이용한 솔더의 젖음성 분석
정도현,임동욱,백범규,임송희,윤종혁,정재필,Jung, Do-hyun,Lim, Dong-uk,Baek, Bum-gyu,Yim, Song-hee,Yoon, Jong-hyuk,Jung, Jae Pil 한국마이크로전자및패키징학회 2017 마이크로전자 및 패키징학회지 Vol.24 No.2
Recently, there has been a continuous researches on solders having sophisticated and improved performance due to demand for high-density and miniaturization of electronics, and development of solder for automotive electronics which can be used in harsh environment. When developing a new solder alloy, there is a wettability of solder on substrate for things to consider, and the wetting balance test is one of the methods for measuring that one. In this paper, the wetting balance test is introduced, and the calculus of the surface tension of solder and the contact angle between solder and substrate using wetting curve obtained is introduced too. In detail, the principle and test method of the wetting balance test, the introduction of the parameters with important meaning in the wetting curve, the method of calculating the contact angle as well as the surface tension of the solder using the shape of the solder meniscus.
정도현 ( Do Hyun Jung ) 한국산림과학회 1995 한국산림과학회지 Vol.84 No.3
This research was carried out to investigate the influences of forest road characteristics and rainfalls on the amount of erosion on the newly - constructed forest road in the Research Forests of Seoul National University located in Mt. Backwoon-san, Kwangyang. Amount of soil erosion on the newly - constructed forest road was measured for 2 years since the forest road construction. Using the stepwise multiple regression method, amount of soil erosion from cut -slopes. fill slopes, road surfaces, and side - ditches were seperately expressed as a function of statistically significant road design and rainfall factors, and multiple regression models to estimate the amount of soil erosion were significant to explain the variance in erosion by each structures. According to results of this study, amount of erosion from the newly - constructed forest road cwas estimated as much as 668.51m/㎞ for 2 years. Out of total amount of soil erosion, 21.9%(144.27m/㎞) from cut-slopes, 39.8.%(261.89m/㎞) from fill-slopes, 8.1%(53.33m/㎞) from road surfaces, and 30.2%(199.02m/㎞) from side - ditches were occurred.
Sn3.0Ag0.5Cu 솔더 볼의 고속 전단특성에 미치는 전단속도 및 UBM층의 영향
정도현 ( Do Hyun Jung ),이왕구 ( Wang Gu Lee ),정재필 ( Jae Pil Jung ) 대한금속재료학회(구 대한금속학회) 2011 대한금속·재료학회지 Vol.49 No.8
The effect of high shear speed on shear force, shear energy and fracture surface was investigated for the solder joint of a Sn-3.0Ag-0.5Cu ball. For both ENIG and OSP pads, the shear force increased with an increase in shearing speed to 0.3 m/s. However, for an ENEPIG pad, the shear force increased with an increase in shear speed to 0.6 m/s and kept almost constant afterward. The shear energy decreased with an increase in shearing speed for ENIG and OSP pads. For the ENEPIG pad, however, the shear energy almost remained constant in a shearing speed range 0.3-3.0 m/s. The fracture mode analysis revealed that the amount of brittle fracture for the ENIG and the OSP pads increased with shearing speed, and a complete brittle fracture appeared at 1.0 m/s for ENIG and 2.0 m/s for OSP. However, the ENEPIG pad showed only a ductile fracture until 0.25 m/s, and a full brittle fracture didn`t occur up to 3.0 m/s. The fracture mode matched well with the shear energy. The results from the high speed shear test of SAC305 were similar to those of SAC105.
정도현,노명환,이준형,김경흠,정재필,Jung, Do-hyun,Roh, Myung-hwan,Lee, Jun-hyeong,Kim, Kyung-heum,Jung, Jae Pil 한국마이크로전자및패키징학회 2017 마이크로전자 및 패키징학회지 Vol.24 No.1
Recently, research and application for a power module have been actively studied according to the increasing demand for the production of vehicles, smartphones and semiconductor devices. The power modules based on the transient liquid phase (TLP) technology for bonding of power semiconductor devices have been introduced in this paper. The TLP bonding has been widely used in semiconductor packaging industry due to inhibiting conventional Pb-base solder by the regulation of end of life vehicle (ELV) and restriction of hazardous substances (RoHS). In TLP bonding, the melting temperature of a joint layer becomes higher than bonding temperature and it is cost-effective technology than conventional Ag sintering process. In this paper, a variety of TLP bonding technologies and their characteristics for bonding of power module have been described.
미분말 음이온교환수지를 이용한 모르타르의 염소이온 고정 능력에 대한 실험적 연구
정도현 ( Jung Do Hyun ),이윤수 ( Lee Yun Su ),이한승 ( Lee Han Seung ) 한국구조물진단유지관리공학회 2018 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.22 No.2
When the reinforced concrete structure is in a high salinity environment, chlorine ions penetrate from the surroundings, resulting in corrosion of the reinforcing bars, resulting in low durability. Therefore, studies on the immobilization of chlorine ions are underway, and anion exchange resin, one of them, was used in this study. In this study, chloride ion fixing ability was confirmed by replacing OPC, conventional bead anion exchange resin, and powder anion exchange resin with mortar and then using an electron probe X-ray micro-analyzer. The bead anion exchange resin replaced 3% of the fine aggregate volume and the powder anion exchange resin 5% of the cement volume. The fabricated specimens were cured for 28 days, immersed in NaCl solution for 28 days, and confirmed by electron probe X-ray micro-analyzer.
정도현 ( Do Hyun Jung ) 한국공업화학회 2013 공업화학전망 Vol.16 No.1
재제조산업은 환경이 중요하게 대두되고 자원이 고갈되어가는 시점에서 중요한 이슈가 되고 특히 자동차에 대한 재활용 기술은 이미 중요한 몫을 차지하게 되었다. 폐차되거나 정비를 위하여 탈거된 부품들과 사용 후 부품들을 어떻게 효율적으로 재제조하여 다시 사용할 수 있는가는 자동차의 유해물질 사용제한, 재활용 용이성 제고, 재활용 정보제공 등을 주요내용으로 하는 "전기·전자제품 및 자동차의 자원순환에 관한 법률"을 2007년 4월 제정하여 시행하고 있을 만큼 중요한 이슈로 대두된 것이다. 본 연구에서는 앞으로 재제조 대상부품은 확대되고 전자화로 인하여 변화될 것이나 재제조에 대한 이해를 넓히기 위해서 현재 시점에서의 재제조의 대상과 그 효과를 소개하였으며, 재제조품이 소비자로부터 신뢰를 얻을 수 있는 있는 품질 확보방법을 논하였다.