http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김도연,김형재,이상직,정해도 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.2 No.2
Sapphire wafers are widely used as substrates for fabricating gallium nitride light-emitting diodes. The quality of light-emitting diodes depends on the total thickness variation and BOW of the wafers. The multi-wire saw process is critical in determining post-processing times for steps such as diamond mechanical polishing and chemical mechanical polishing. In particular, thickness variation is affected by wear of diamond wires, which in turn is controlled by cutting conditions including wire speed, feed rate, initial contact condition between ingot and wire, and new wire consumption. Thickness variation shows a marked change from the initial to final feeding location during the multi-wire sawing process. A wire is not worn when it is initially contacted by an ingot. Hence, the initial kerf loss is greater than the kerf loss at the final feeding location. This study focused on minimizing the thickness variation between the initial and final contact points of the wafer. Experiments were conducted with different initial wire deflection conditions. The experimental results showed that increasing the wire deflection increased the cutting load, which in turn caused severe wear of the wire. Consequently, the thickness variation of the wafer in the multi-wire sawing process was controlled by adjusting the wire deflection.
태양전지용 실리콘 웨이퍼의 멀티 와이어 쏘잉 시 절삭저항력에 관한 연구
황인환(In-Hwan Hwang),박상현(Sang-Hyun Park),안국진(Kuk-Jin An),권대근(Geon-Dae Kwun),이종찬(Chan-Jong Lee) 한국기계가공학회 2016 한국기계가공학회지 Vol.15 No.3
Reducing the wafer breakage rate and sawing thinner wafers will decrease the cost of solar cells. This study was carried out in order to identify ways to achieve this goal. In this study, the cutting force characteristics using an ingot tilting-type diamond multi wire-sawing machine were analyzed. The cutting force was analyzed while varying the tilting angles and wire speed. The obtained data were analyzed by classifying the tangential cutting force and the normal cutting force. In this cutting force experiment, the difference between the forces was confirmed; it was found that it rises with increasing the tilting angles and decreases when the wire speed elevates. The resulting value can be utilized as basic data for the determination of an ideal cutting recipe.
멀티 와이어 쏘 메인 롤러의 길이, 직경 및 두께 변화에 따른 변형 해석
김정현(Junghyun Kim),안지호(Ji Ho Ahn),이교우(Gyo Woo Lee) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
In this study, the deformation of a guide roller of the multi-wire saw was analyzes with the variation of the design parameters like length, diameter and thickness of the roller. The roller could be deformed by tensioned saw wires during cutting. We attempted to suggest a range of design variables that would satisfy the desirable wafer thickness variation. The analysis conditions were verified by comparing the experimental result with that of simulation, and the deformation of the modeled rollers was analyzed with several parameters. CATIA V5R21, a co㎜ercial drawing program, was used to model rollers similar to those of the actual multi-wire saw in various lengths, diameters and thicknesses, and were analyzed by ANSYS 17, a co㎜ercial analysis program. As a result of analysis, the larger the diameter, the shorter the length, and the thicker the thickness, the smaller the deformation of the roller. In addition, when the length-to-diameter ratio and the thickness-to-length ratio were the same, the shorter the length, the smaller the deformation. Based on the results, under the given conditions, when the length-to-diameter ratio was 1.5 or less and the thickness-to-length ratio was 0.17 or more, the deformation of the roller could be predicted within 5 ㎛, which was the design criterion in this study.
김도연,김형재,이상직,이태경,정해도 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.2
Diamond abrasive-coated wire is a tool for the precise multi-wire sawing of mono-crystal ingots to manufacture substrates. This tool is used to cut hard materials such as silicon carbide, gallium nitride, sapphire and silicon. The cutting performance of diamond wires strongly influences the accuracy of substrates in terms of roughness, total thickness variation and BOW. Nonetheless, changes in cutting performance as a result of gradual wear through repeated contact complicate the optimization of diamond wire use. A characterization method is proposed for the cutting performance and lifetime of a diamond wire based on mathematical modeling and experimental results. The theoretical model predicts that cutting accelerates with the application of a strong feed force and small abrasives due to an increase in indentation depth for each abrasive. Experimental results showed that a wire with a low concentration exhibited an increased material removal rate. However, the lifetime of the wire displayed an opposite trend; that of a diamond wire can be classified into two regimes. The first one is an increased loss of abrasives as a result of rapid wear attributed to a low concentration; the second regime is caused by a drop in actual contact pressure due to the enlarged contact area between the workpiece and the bonding material enveloping the abrasives.
스프링 요소를 이용한 멀티와이어쏘 장비의 베어링 배치 설계에 관한 연구
박혜량(Hye Ryang Park),이준영(Jun Young Lee),임홍재(Hong Jae Yim),정재일(Jay Il Jeong) 한국소음진동공학회 2019 한국소음진동공학회 논문집 Vol.29 No.4
In this paper, bearing arrangements for multi-wire saw were studied with the aim of reducing time and material loss in the after-treatment process. Due to the displacement of the spindle during the cutting process, the workpieces are curved. To improve the stiffness of the spindle, a bearing arrangement was performed. Because the mass of the spindle assembly is maintained in a bearing arrangement, the stiffness increases if the natural frequency increases. The bearing used in this study are angular contact ball bearings, which support both radial and axial loads. Angular contact ball bearings are modeled as a spring element that can take into account the contact angle between the spindle and the bearing. After the bearing arrangement, the natural frequency increased by 8.8 % in the first bending mode and by 9.9 % in the second bending mode, compared with the base model.