• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.706-709
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• 2005

Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed in multi-cavity injection mold. These filling imbalances are results from non-symmetrical shear rate distribution within melt as it flows through the runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during the injection molding processing. This paper presents a solution of these filling imbalances by using runner core pin which creates a symmetrical shear distribution within runner and the effects on filling imbalance when modifying a shape of runner core pin. As a result of using runner core pin, a remarkable improvement in reducing filling imbalance was confirmed. In addition we investigated how filling imbalances were affected by shape of runner core pin.

• Geomechanics and Engineering
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• 제18권4호
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• pp.417-426
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• 2019

Gangue filling in the goaf is an effective measure to control the surface subsidence. However, due to the obvious deformation of gangue compression, the filling effect deserves to be further studied. To this end, the deformation of coal gangue filling in the goaf is analyzed by theoretical analysis, large-scale crushed rock compression test, and field investigation. Through the compression test of crushed rock, the deformation behaviour characteristics and energy dissipation characteristics is obtained and analysed. The influencing factors of gangue filling and predicted amount of main deformation are summarized. Besides, the predicted equation and filling subsidence coefficients of gangue are obtained. The gangue filling effect was monitored by the movement observation of surface rock. Gangue filling can support the roof of the goaf, effectively control the surface subsidence with little influence on the ground villages. The premeter and equations of the main deformation in the gangue filling are verified, and the subsidence coefficient is further reduced by adding cemented material or fine sand. This paper provides a practical and theoretical reference for further development of gangue filling.

• Geomechanics and Engineering
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• 제22권6호
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• pp.541-552
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• 2020

With the increasing tension of current coal resources and the increasing depth of coal mining, the gob-side entry retaining technology has become a preferred coal mining method in underground coal mines. Among them, the technology of the gob-side entry retaining with the high-water filling material can not only improve the recovery rate of coal resources, but also reduce the amount of roadway excavation. In this paper, based on the characteristics of the high-water filling material, the technological process of gob-side entry retaining with the high-water filling material is introduced. The early and late stress states of the filling body formed by the high-water filling materials are analyzed and studied. Taking the 8th floor No.3 working face of Xin'an coal mine as engineering background, the stress and displacement of surrounding rock of roadway with different filling body width are analyzed through the FLAC^3D numerical simulation software. As the filling body width increases, the supporting ability of the filling body increases and the deformation of the surrounding rock decreases. According to the theoretical calculation and numerical simulation of the filling body width, the filling body width is finally determined to be 3.5m. Through the field observation, the deformation of the surrounding rock of the roadway is within the reasonable range. It is concluded that the gob-side entry retaining with the high-water filling material can control the deformation of the surrounding rock, which provides a reference for gob-side entry retaining technology with similar geological conditions.

• 마이크로전자및패키징학회지
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• 제21권4호
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• pp.117-123
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• 2014

써멀비아나 수직 배선으로 사용하기 위한 Cu 관통비아를 열린 비아 hole의 top-down filling 도금공정과 bottom-up filling 도금공정으로 형성 후 미세구조를 관찰하였다. 직류도금전류를 인가하면서 열린 비아 홀 내를 top-down filling 도금하거나 bottom-up filling 도금함으로써 내부기공이 없는 건전한 Cu 관통비아를 형성하는 것이 가능하였다. 열린 비아 홀의 top-down filling 공정에서는 Cu filling 도금 후 시편의 윗면과 밑면에서 과도금된 Cu 층을 제거하기 위한 chemical-mechanical polishing(CMP) 공정이 요구되는데 비해, 열린 비아 홀의 bottom-up filling 공정에서는 과도금된 Cu층을 제거하기 위한 CMP 공정이 시편 윗면에서만 요구되는 장점이 있었다.

• Restorative Dentistry and Endodontics
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• 제13권1호
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• pp.41-52
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• 1988

The purpose of this study was to investigate the pulpal responses to acid etching of dentine. Total 72 class V cavaties' were prepared on the healthy permanent teeth from 6 dogs, and were divided into 4 groups. These were filled with filling materials after acid etching with each etchant for 1 min. Control group ; ZOE filling without acid etching. Group 1: Zinc Oxide-Eugenol cement filling. Group 2: Drying with hot air and Zinc oxide-Eugenol cement filling. Group 3: Scotchbond application and silux filling. Group 4: Silux filling. The dogs were sacrificed after 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks and 6 weeks following operation. The specimens were routinely prepared and stained with Hematoxylin and Eosin. Followings were the results obtained through microscopic examination. 1. There was mostly severe pulpal responses in case of Silux filling after acid etching of dentine. 2. The pulpal responses of Silux filling after acid etching and application of Scotch bond group were more severe compared to Zinc Oxide-Eugenol cement filling group, but less severe compared to Silux filling group after acid etching of dentine. 3. The pulpal responses of Zinc Oxide-Eugenol cement filling group were similar to those of Zinc Oxide-Eugenol cement filling after drying with hot air group. 4. There was slight pulpal responses in early stage in case of Zinc Oxide-Eugenol cement filling group, but recovered to normal state soon after.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.499-512
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• 1994

The purpose of this study was to evaluate the microleakage electrochemically using different retrograde filling materials, different root resection angle, and different cavity preparation instruments. 104 extracted single-rooted teeth were selected for this study. 100 teeth were used as experimental groups and four was used as controls. Anatomical crowns were resected, root canals were prepared, and the apical 2 mm of roots were removed. The experimental roots were randomly divided into five equal groups. Experimental groups : Group 1. no bevel, cavity preparation with ultrasonic instruments, amalgam filling Group 2. no bevel, cavity preparation with ultrasonic instruments, SuperEBA cement filling Group 3. no bevel, cavity preparation with ultrasonic instruments, desiccated ZOE filling Group 4. $45^{\circ}$ bevel, cavity preparation with ultrasonic instruments, amalgam filling Group 5. no bevel, cavity preparation with conventional bur, amalgam filling Microleakage was measured once a day for 30 days using electrochemical method and were analyzed statistically. The results were as follows : 1. The group with Super EBA cement filling showed the least marginal leakage from second to fourth day(p<0.05), there was no significant difference between the group with amalgam filling during eighth to eighteenth day(p>0.05), but after the nineteenth day here was a higher marginal leakage than the group with amalgam filling(p<0.05). 2. The group with desiccated ZOE filling demostrated that the highest marginal leakage, started on the eighth day(p<0.05). 3. The group using ultrasonic instrument showed lower marginal leakage than the group using bur until the nineteenth day(p<0.05), but there was no significant differnce with the group using bur after twentythird day(p>0.05). 4. The group without bevel showed lower marginal leakage than the group with bevel (p<0.05). 5. Whether bevel or nor had much more effect on marginal leakage than with cavity perparation instrument when the cavity was retrogrdefilled with amalgam(stepwise regression).

• Journal of Advanced Marine Engineering and Technology
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• 제28권6호
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• pp.931-937
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• 2004

Simultaneous filling is a goal in plastic injection mold that has multi cavities. The moldings which have not been filled at the same time have undesired faults such as dimension inaccuracy, residual stress, law mechanical strength, etc. The best way to simultaneous fill is to be injected in a geometrically balanced runner system. In a general processing, however, in balanced runner system mold, filling imbalance would be observed in cavities. These phenomena result from molten polymer's characteristics and circumstances in balanced runner. In this study, the degree of filling imbalance (DFI) was defined for showing rate of filling imbalance in geometrically balanced injection mold that has 8 cavities. Before the main experiment, an injection molding simulation was conducted to know a pattern of filling imbalance with Moldflow software. There were somewhat differences between results of experiment and simulation about the filling imbalance. The reason for the difference was that the software have not concerned about a situation in a real flow channel. It was also investigated how the injection speed affected on filling imbalance in the experiment.

• 마이크로전자및패키징학회지
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• 제14권3호
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• pp.65-71
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• 2007

칩 스택 패키지에 적용을 위해 폭 $75{\sim}10\;{\mu}m$, 길이 3mm의 트랜치 비아에 대해 도금전류밀도 및 rotating disc electrode(RDE)의 회전속도에 따른 Cu filling 특성을 분석하였다. RDE 속도가 증가함에 따라 트랜치 비아의 Cu filling 특성이 향상되었다. 트랜치 비아의 반폭 길이, 즉 트랜치 비아 폭의 1/2 길이와 이 트랜치 비아에 대해 95% 이상의 Cu filling 비를 얻기 위한 RDE 최소속도 사이에는 Nernst 관계식이 성립하여, 95%이상의 Cu filling비를 얻을 수 있는 최소 트랜치 비아의 반폭 길이는 RDE 속도의 제곱근의 역수에 직선적으로 비례하였다.

• 마이크로전자및패키징학회지
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• 제14권3호
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• pp.37-42
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• 2007

반도체 소자의 집적도가 높아짐에 따라 3D SiP에 대한 관심이 높아지고 전기도금법을 이용한 구리 via filling이 활발히 연구되어왔다. Via filling시 via 입구와 바닥에 전류밀도 차이로 인해 via 내부에 결함이 발생하기 쉽다. 여러 가지 유기물 첨가제와 전류인가 방식의 변화를 통한 via filling을 하였다. 첨가된 유기물은 PEG, SPS, JGB, PEI를 사용하였다. 유기물이 첨가된 용액을 이용하여 펄스와 역펄스 방법을 이용하여 via filling을 하였다. 유기물의 첨가에 따른 도금된 구리 입자의 크기 및 형상에 관하여 고찰하였으며 도금 후 via 시편의 단면을 FESEM으로 관찰하였다. JGB에 비하여 PEI를 사용한 경우 치밀한 도금층을 얻을 수 있었다. 2 step via filling을 사용한 경우 via filling 시간을 단축시킬 수 있었다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.72-75
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• 2003

Almost all injection molds have multi-cavity runner system for productivity and are designed with geometrically balanced runner system in order to minimize filling imbalance between cavity to cavity during processing. However, filling imbalances have been observed though geometrically balanced runner lay-out are used. Generally, these filling imbalances are due to thermal unbalance, viscosity, characteristic of polymers and so on. These kinds of filling imbalances has already been reported by Beaumont[1] since 1997. In this study, we presented filling imbalaces in balanced runner that has unnary branch type lay-out through experimental tests. As a result of experiments, we could present the processing conditions for the balanced filling in geometrically balanced runner that has unnary branch type lay-out