• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권1호
• /
• pp.47-52
• /
• 2004

3D microstructures with different side-wall angles and different scales are fabricated by both methods of inclined exposure and rear-side exposure at each of selected areas on a same substrate. Conventional methods of inclined exposure are used to make side-walls with a same inclined angle on one substrate and to get a scale error due to front-side exposure through thick photoresist layer, But, by using the proposed method, we are able to fabricate 3D microstructures on a same substrate with various side-wall angles and accurate dimensions as the original design. In the rear-side exposure, UV exposure light reflects from the chromium mask pattern after passing through the thick photoresist layer, resulting in fabrication of well-defined, inclined 3D structures inside the thick photoresist layer.

• Journal of Advanced Marine Engineering and Technology
• /
• 제37권5호
• /
• pp.461-466
• /
• 2013

본 논문은 조선해양 구조물 주판의 맞대기용접 수축에 대한 특성을 연구하였다. 주판의 맞대기 용접은 입 열과 냉각과정에서 수축 변형이 일어나 최종 완성된 모재의 치수와 설계 치수가 다르게 된다. 이는 선박의 블록 생산 품질 불량으로서 교정 작업이 필요하며 생산성 향상의 저해요인이다. 이에 대형 구조물 주판의 맞대기용접 수축 변형에 관한 실험을 통하여 I, Y, V 형상의 용접잔류응력 수축 변형 데이터를 확보하고 두께 11 t ~ 21.5 t 범위에서는 1 ~ 2 mm의 한정된 범위의 수축 량이 균일하게 나타나는 특징과 용접부의 열전달 영향이 Seam Line 한쪽을 기준으로 최대 약 1000 mm 이내에 국한되어 모재의 자중이 수축 량에 미치는 영향은 크지 않았고 또한 수축 변형을 최소화하기 위해 설계단계에서 Groove 형상에 따라 수축마진을 다르게 적용해야 함을 알 수 있었다.

• 드라이브 ㆍ 컨트롤
• /
• 제16권4호
• /
• pp.87-92
• /
• 2019

Rotary dampers are damping devices which provide high resistance to shaft rotation. Rotary dampers are being used in various areas to enable the gentle opening and closing of the rotation motion relative to home furniture, industry machinery and automotive parts. Rotary dampers can be installed directly at the rotating point of a various part and can achieve uniform, gentle movement which increases quality and value of products. And generally, the silicone fluid is used as the damping medium because of its stable viscous properties. The movement of these little decelerators can be achieved with a high viscosity of working fluid and throttles installed in the body of the rotary damper. The damping force can be achieved clockwise, anti-clockwise or in both directions according to the structure of the orifices or throttles. In this paper, the torque performances of the rotary damper containing air in the working fluid were studied. For this purpose, the torque characteristic of the rotary damper according to the variation of various operating conditions such as clearance of leakage, dimensions of groove orifice, content ratio of air, etc., were simulated with AMEsim software.

• 소성∙가공
• /
• 제23권4호
• /
• pp.221-230
• /
• 2014

This study deals with a series of experimental investigations on multi-stage cold forging of an outer race used for a constant velocity (CV) joint with six inner ball grooves. The multi-stage cold forging, which consists of forward extrusion, upsetting, backward extrusion, and combined sizing-necking including ironing, was used to produce a prototype of the outer race. The cold forging tools such as forging punches and dies required in this multi-stage cold forging were also designed and fabricated. For the combined sizing-necking, especially, the longitudinally six-segmentallized punches were developed to easily eject from the necked inner groove of the outer race with consideration of the operating mechanism. Spheroidized SCr420H billet was used in the experimental study. To verify the suitability of the proposed process, the obtained parts were obtained from each forging operation, and the geometries were compared with the target dimensions. It was confirmed that the outer race with six inner ball grooves was well forged by adopting the proposed multi-stage cold forging, and the dimensional accuracy of the forged outer race matched well with the requirements.

• 한국태양에너지학회 논문집
• /
• 제36권3호
• /
• pp.25-31
• /
• 2016

Gaskets are usually used for the sealing of flange joints. The joint is usually composed of two flanges, a ring gasket and clamping bolts. The metal ring gasket is suitable for pipe flanges, pumps and valve joints in high temperature and high pressure environments. A very high surface stress is developed between a ring type joint gasket and the flange groove when the ring type joint is bolted up in a flange. The dimensions of flanges and ring joint gaskets for the pipe sizes that are in common use are specified in the ANSI codes. However, sometimes it is necessary to make a new design for the flange joint which is not specified in the codes, as the equipment is getting larger and larger in size. This paper presents the contact behavior of Class 600 ring joint gaskets with oval and octagonal cross sections. Five different sizes of gaskets are employed in the analysis, and one of them is newly designed on the basis of analysis results obtained from existing models. Three load steps are used to find the stress, stain and contact pressure etc., and to compare the contact characteristics among the models due to the bolt clamping force and the working surface pressure. ANSYS Workbench version15 is used to conduct the finite element analysis.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
• /
• pp.136-139
• /
• 2004

The requirement of planarity, such as with-in-wafer nonuniformity, post thickness range, have become increasingly stringent as critical dimensions of devices are decreased and a better control of a planarity become important. The key factors influencing the planarity capability of the CMP process have been well understood through numerous related experiments. These usually include parameters such as process pressures, relative velocities, slurry temperature, polishing pad materials and polishing head structure. Many study have been done about polishing pad and its groove structure because it's considered as one of the key factors which can decide wafer uniformity directly. But, not many study have been done about polisher head structure, especially about polisher head plate design. The purpose of this paper is to know how the plate structure can affect wafer uniformity and how to deteriorate wafer yield. Furthermore, we studied several new designed plate to improve wafer uniformity and also improve wafer yield.