• 한국정밀공학회지
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• 제10권1호
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• pp.147-152
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• 1993

The lapping characteristics of single crystal diamond are studied by considering the crystallographic anisotropy. It is introduced for lapping method to identify crystallographic orientantion by the X-ray diffraction and to measure lapping force ratio, lapping temperature and lapping wear. Diamound bonded wheels are used for lapping under dry condition. On the lapping {110} and {100} planes, it shows remarkable crystallographic anistropy. The lapping force ratio, temperature and wear become gerater with sliding direction along the <100> than along <110>. The results also show that the wear of diamond is influenced by mechanical work(tangential lapping force * lapping distance) as well by lapping speed.

• 대한기계학회논문집A
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• 제29권4호
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• pp.632-638
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• 2005

The surface lapping process on sapphire wafer was carried out for the epitaxial process of thin film growth of GaN semiconducting material. The planarization of the wafers was investigated by the introduction of the dummy wafers. The diamond lapping process causes the surface deformation of dislocation and micro-cracks. The material deformation due to the mechanical stress was analyzed by the X-ray diffraction and the Vickers indentation. The fracture toughness was increased with the increased annealing temperature indicating the recrystallization at the surface of the sapphire wafer The sudden increase at the temperature of $1200^{\circ}C$ was correlated with the surface phase transition of sapphire from a $-A1_{2}O_{3}\;to\;{\beta}-A1_{2}O_{3}$.

• 열처리공학회지
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• 제2권2호
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• pp.33-37
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• 1989

In order to improve hardness uniformity of standard-hardness blocks. experimental procedure was designed using Taguchi Method. For this purpose the following factors were studied: austenitizing temperature, tempering condition, grinding condition, subzero treatment, lapping time, $15{\mu}m$ polishing time, final polishing time. These factors were processed and then ten hardness values were measured on each specimen. SN (signal to noise) ratio for each condition was calculated with standard variations of these values. Finally, from the calculated value of ANOVA on SN ratios, the lapping time was found to be the main factor Better uniformity with longer lapping time implies that residual stress that was formed after quenching is a dominent parameter that affects on the uniformity of hardness. Therefore, step-quenching method was adapted to minimize the residual stress. By this modification of quenching procedure, the hardness uniformity was improved remarkably and the yield ratio was increased from 55% to 88%.

• 한국정밀공학회지
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• 제25권7호
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• pp.47-54
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• 2008

Recently, application of ceramics has increased gradually due to excellent mechanical properties. Si3n4-BN ceramic which is one of ceramics is very hard and has superior resistance against volatile temperature and wear. However, extremely high hardness of the $Si_3N_4-BN$ ceramic makes conventional machining very difficult. Therefore, the use of machinable ceramic has been in a poor because of difficult industrial processes in spite of many advantages. And so new technology being called IED(In-process electrolytic dressing) was introduced to solve this problem. The aim of this study is to determine the machining characteristics in terms of pressurized weight to the workpiece and the influence with h-BN content using IED lapping system. Also, Acoustic Emission (AE) is used for the monitoring of surface characteristics.

• 한국결정성장학회지
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• 제11권5호
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• pp.218-223
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• 2001

수평 Bridgman 방법으로 성장한 사파이어 인고트를 절단 연마한 후, 사파이어 결정기판의 표면을 우레탄 천 위에서 실리카 졸을 사용하여 폴리싱하였다. 표면의 결정성을 X-선 회절을 통하여 조사하였으며, 2중 결정회절에 의한 반치폭은 200~400 arcsec을 가지며, 결정 인고트의 절편화 또는 양면 연삭 연마에 따른 잔류응력에 의한 표면에서의 기계적인 스트레스에 의해 결정성이 손상되어진다. 화학-기계적인 폴리싱공정을 수행한 수에 표면처리로 $1,200^{\circ}C$로 4시간 열처리 및 산처리를 연속적으로 수행할 경우 결정성이 반치폭 8.3 arcsec까지 줄어들어 향상됨을 확인하였다.

• 한국통신학회논문지
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• 제7권2호
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• pp.59-65
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• 1982

本實驗에 파이퍼-폴리시(piper-polish)法으로 만든 單結晶에 Sb와 In을 이온衝激시킨 스포트에 대하여 熱剌激電流를 測定하였다. Sb와 In을 각각 衝激시켜 熱剌激電流를 測定한 결과 중첩된 피이크가 觀察되었는데 이를 서멀 클리닝(thermal cleaning)法으로 分離하여 147K에서 0.25eV와 0.31eV의 活性에너지를 얻었다. 스포트를 冷却시키면서 光勵起시키면 0.25eV의 트랩(trap)이 사라지고 0.85eV의 트랩이 새로 나타났다. 光電導가 양호한 結晶에서 T.S.C.가 잘 測定되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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• pp.68-71
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• 2000

In this paper, we have measured the oxygen contents by FTIR in silicon wafer various process technology(slicing, lapping, polishing). The measured data are also compared with the data of etching process(KOH, Bright etching). Also we have measured the surface morpology in backside silicon wafer after etching treatment and etch pit density due to OISF after 4 step high temperature annealing process with optical microscope.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.21-25
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• 2008

In this paper, the temperature history and the strength development of concrete corresponded to various bubble sheets layer and curing temperature. Based on the results, In case of the test temperature of -5℃, concrete subject in the exposure condition, result in a frost damage at initial stage by a fall of below zero temperature. In case of the combination of PE film and non woven fabric was after 36 hour, and combination of bubble sheet over double, a tremendous insulating effect of bubble sheet over double is confirmed due to the temperature of concrete fall of below zero temperature after 60 hours. Meanwhile, regarding the -15℃ of temperature, special measure for insulation curing is necessary to secure stability against early frost damage because frost damage was not affected by the lapping thickness of bubble sheet subjected to severe cold weather condition.

• 한국표면공학회지
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• 제33권2호
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• pp.101-106
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• 2000

SOI (Silicon-On-Insulator) substrates were fabricated with varying annealing temperature of $25-660^{\circ}C$ by a linear annealing method, which was modified RTA process using a linear shape heat source. The annealing method was applied to Si ∥ $SiO_2$/Si pair pre-contacted at room temperature after wet cleaning process. The bonding strength of SOI substrates was measured by two methods of Razor-blade crack opening and direct tensile test. The fractured surfaces after direct tensile test were also investigated by the optical microscope as well as $\alpha$-STEP gauge. The interface bonding energy was 1140mJ/m$^2$ at the annealing temperature of $430^{\circ}C$. The fracture strength was about 21MPa at the temperature of $430^{\circ}C$. These mechanical properties were not reported with the conventional furnace annealing or rapid thermal annealing method at the temperature below $500^{\circ}C$. Our results imply that the bonded wafer pair could endure CMP (Chemo-Mechanical Polishing) or Lapping process without debonding, fracture or dopant redistribution.

• 수산해양기술연구
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• 제47권3호
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• pp.267-272
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• 2011

The behavior of abrasive wear on counterpart roughness of glass fiber reinforcement polyurethane resin (GF/PUR) composites were investigated at ambient temperature by pin-on-disc friction test. The friction coefficient, cumulative wear volume and surface roughness of these materials against SiC abrasive paper were determined experimentally. The major failure mechanisms were lapping layers, ploughing, delamination, deformation of resin and cracking by scanning electric microscopy (SEM) photograph of the tested surface. As increasing the counterpart roughness the GF/PUR composites indicated higher friction coefficient. The surface roughness of the GF/PUR composites was increased as the sliding velocity was higher and the counterpart roughness was rougher in wear test.