Strength Properties of a LTCC Substrate Material with an Anorthite Glass Composition

신효순,박지훈,여동훈,김종희,Sahn Nahm,구신일 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

High strength in LTCC material for module fabrication is increasingly required with trends of multi-functionality and miniaturization of electronic devices for mobile communications. The anorhtite glass system is known a recrystallized glass with high strength and additives such as Zn and B are thought to affect the strength, as well as main components of Ca, Si and Al. In this study, therefore, the sintered density, the 3-point bending strength, the dielectric properties and the microstructure of a sintered body were investigated for various amounts of Zn and B. As the boron amount was increased, the glass transition temperature (Tg) of the glass and the sintered density decreased due to the increased porosity accompanying a low strength and a low quality factor. With variation of zinc amount, there were no remarkable changes in Tg or the microstructure. The highest strength of 358 MPa was obtained with 4 % Zn and 18 % B. The dielectric constant and the quality factor at that condition were 7.17 and 640, respectively.

버전스용이와 융합버전스의 관계

신효순 한국안광학회 2009 한국안광학회지 Vol.14 No.3

목적: 버전스용이가 융합버전스에 대해 임상적으로 의미 있는 추가정보를 제공하는지에 대해 명확하지 않다. 이 연구에서는 눈증상이 있는 집단을 대상으로 버전스용이와 융합버전스의 관계를 확인해보고자 한다. 방법: 선별검사 를 실시하여 선정된 눈증상이 있는 9세에서 13세 사이의 남여 114명을 대상으로 하였다. 버전스용이 검사는 8D BI/ 8D BO 플리퍼 렌즈와 단안 억제방지를 위해 Vectogram 9(Bernell, USA)의 20/30 시표를 사용하여 측정하였다. 근 거리의 융합버전스는 20/30 수직단일시표를 사용하여 Von Graefe 기법을 이용하였고, 과다한 눈모임자극을 방지하 기 위하여 음성 융합버전스 범위(흐린점, 분리점, 회복점)를 측정한 후 양성 융합버전스 범위(흐린점, 분리점, 회복 점)를 측정 하였다. 결과: 버전스용이와 융합버전스의 다양한 측정값에 대해 실시한 Pearson 상관성 분석에서 버전 스용이와 융합버전스의 어느 값과도 관련성이 없는 것으로 나타났다(p>0.05). 그리고 편안한 양안시를 위해 Sheard 와 Morgan의 융합력 평가기준을 만족하는 경우와 만족하지 못하는 경우에 대한 버전스용이를 비교한 결과에서도 유의한 차이를 보이지 않았다(p>0.05). 결론: 증상이 있는 집단을 대상으로 한 버전스용이와 융합버전스는 관련성이 없음을 확인하였다. 따라서 양안시이상을 정확하게 진단하고 효율적인 관리계획을 수립하는데 도움을 주기위하여 버전스용이와 융합버전스를 모두 측정해야 할 것이다. Purpose: There is uncertainty if the vergence facility would provide clinically significant supplementary information to the fusional vergence measurements. The purpose of this study was to determine the relationship between vergence facility and fusional vergence in a group of symptomatic subjects. Methods: A total of 114 symptomatic subjects aged 9 to 13 years, who passed the vision screening test, participated in this study. Vergence facility was measured with 8D BI/8D BO flipper lenses and a suppression control target, the 20/30 letter line on Vectogram 9 (Bernell, USA). Near fusional vergence was measured with a single 20/30 vertical line target by Von Graefe technique. In order to avoid excessive convergence stimulation, negative fusional vergence (NFV) range (blur, break and recovery) was measured followed by positive fusional vergence (PFV) ranges (blur, break and recovery). Results: Pearson correlations were calculated and showed no correlations between vergence facility and any of fusional vergence measurements (p>0.05). Also, there were no significant differences of vergence facility measurements on the compensating vergence that passed or failed Sheard and Morgan's criterion for comfortable vision (p>0.05). Conclusions: There was no correlation between vergence facility and fusional vergence among symptomatic subjects. Hence, both vergence facility and fusional vergence should be assessed for those with binocular dysfunction in order to make an accurate diagnosis and management plan.

소결온도와 B2O3 첨가량에 따른 Mn 첨가 PMN-PZT의 유전 및 압전특성의 변화

신효순 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.9

The additive of low temperature sintering in Mn-doped PMN-PZT known as high piezoelectric materials was studied in this experiment. B2O3 was used for the additive of low temperature sintering. The effects of sintering temperature in dielectric, and piezoelectric properties were investigated with the amounts of B2O3. Sintered density was increased in comparison with no addition and under 2wt% B2O3 and lower sintering temperature than 1000℃. Therefore, in the low sintering temperature, the densification was improved by the addition of the B2O3. However, the sintering density was lower than that of the main composition in the case of the sintered at over 1050℃. Dielectric constant with the addition of B2O3 was evaluated. The dielectric constant was 1000 2wt% of B2O3 and sintered at 1000℃. Under 2wt% of B2O3, the electromechanical coupling factor and the piezoelectric constant were not so much decreased. The electromechanical coupling factor and the piezoelectric constant were 50% and 300(×10-12C/N), respectively. The mechanical quality factor was increased with B2O3. The mechanical quality factor was 1700 at 0.5wt% B2O3 and sintered at 1100℃. Dielectric loss was less than 0.5% regardless of the amount of B2O3. 우수한 압전 특성을 나타내는 것으로 알려진 Mn 첨가 PMN-PZT의 저온소결 첨가제가 실험되었다. 저온소결 첨가제로는 B2O3 가 사용되었고 소결온도와 B2O3 첨가량의 변화가 소결성과 유전 및 압전특성의 변화에 미치는 영향을 조사하였다. B2O3 첨가량과 소결온도를 변화시킨 결과 B2O3 첨가량 2wt%이하 1000℃이하 조건에서 소결밀도가 증가하여 B2O3가 저온소결재로 작용하였다. 그러나 1050℃ 이상에서는 주조성인 PMN-PZT 보다 낮은 소결밀도를 나타내었다. B2O3 첨가에 따른 유전상수(ε33T)의 변화를 확인할 결과 B2O3 2wt% 1000℃ 조건에서 1000의 유전율을 나타내었다. B2O3 첨가량이 전기-기계 결합계수(kp)와 압전상수(d33)에 큰 저하를 가져오지 않는 B2O3 첨가 한계는 2wt% 이하로 나타났다. 이때, kp는 약 50%, d33는 약 300(X10-12C/N) 정도의 값을 얻을 수 있었다. B2O3 첨가는 기계적 품질계수(Qm)의 증가를 가져왔으며 0.5wt% B2O3 첨가 1100℃ 소결 조건에서 1700의 품질계수를 나타내었다. 유전손실은 B2O3 첨가에 따라 큰 변화 없이 0.5% 이하의 값으로 나타났다.

무선충전 기술현황 및 전망

신효순 한국조명·전기설비학회 2014 조명.전기설비 Vol.28 No.3

Sol-Gel Process를 利用한 Y-SrTiO_3 微分體 合成

申孝順,이병교 경북대학교 산업기술연구소 1992 産業技術硏究誌 Vol.20 No.-

Y-SrTiO_3 powders are synthesized by pechini process as a kind of sol-gel process and compared with powders by solid state reaction with respect to powder properties. As a result, calcination temperature is lowered about at 500℃. Furthermore, obtained powders are fine and homogeneous. And these powders are agglomerated and the size of primary particles is about 30㎚.

졸 코팅 법을 이용한 BaTiO₃ 분체의 첨가제 코팅 I - BaTiO₃ 졸 코팅 공정 연구

신효순 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.9

BaTiO$_3$ powder has been applied in so much electronic ceramics. Therefore, as recent, the method to add or coat additive will be needed BaTiO$_3$ powder. As a kind of the method, the coating of BaTiO$_3$ powder was considered. In this study, during BaTiO$_3$ powder was coated by BaTiO$_3$ sol, gelation path was experimented. Standard coating condition was set for homogeneous coating. The phase of the gel was deferent by gelation path. It was confirmed the amorphous gel was made in BaTiO$_3$ phase easily at low temperature. In the amorphous gel, particle growth was shown at 900$^{\circ}C$, because crystallization temperature was low. The optimal ratio of sol and powder was at 10 vol% for the homogeneous coating.

외사위의 정도와 입체시의 관계

신효순,윤미옥,김미연,배홍섭,박상철,이선행 한국안광학회 2009 한국안광학회지 Vol.14 No.2

urpose: Stereopsis is one of primary characteristics for assessment of binocular function. The purpose of this study was to determine the possible relationship between the degree of exophoria and stereoacuity at near. Methods: 110 exophores (male n=71, female n=39, mean ageSD=11.301.47 years) without amblyopia, strabismus, and ocular and systemic pathology were studied. Subjects were also excluded if they had visual acuity poorer than 0.8 in either eye or vertical phoria greater than 1 prism diopter. Clinical tests were performed for near phorias by von Graefe technique using a Digital Refractor (CDR-3100, Huvitz, Korea) with chart (Predio CDC-4000, Huvitz, Korea), and for stereoacuity using the Titmus fly. Results: A one-way analysis of variance revealed that mean values of the stereoacuity classified according to the degrees of the exophoria were not significantly different (p>0.05). Conclusions: Based on the result of this study, it was found that there was no relationship between the degree of exophoria and stereoacuity. 목적: 입체시는 양안시 기능을 평가하는 중요한 기준의 하나이다. 이 연구에서는 근거리에서 외사위의 정도와 입 체시의 관계를 확인해 보고자 한다. 방법: 사시나 약시 및 안질환이나 전신질환이 없고 근거리 단안 시력이 모두 0.8 이상이면서 수직사위가 1 프리즘 디옵터 미만인 110명(남자 71명, 여자 39명, 평균 나이 11.301.47세)의 외사 위안을 대상으로 하였다. 근거리의 사위는 디지털 검안기(CDR-3100, Huvitz, Korea)와 디지털 챠트(Predio CDC-4000, Huvitz, Korea)를 사용하여 Von Graefe 기법으로 측정하였고, 근거리의 입체시는 Titmus fly를 사용하여 측정 하였다. 결과: 외사위의 정도에 따라 분류한 입체시의 평균에 대해 일원배치분산분석을 실시한 결과 유의한 차이가 없는 것으로 나타났다(p>0.05). 결론: 이 연구의 결과를 통해 외사위의 정도와 입체시는 관련성이 없음을 확인하였다.

LCTT에서 세라믹스 후막 공정 기술 동향

신효순,Sin, Hyo-Sun 한국전기전자재료학회 2010 전기전자재료 Vol.23 No.12

MLCC의 현황과 전망

신효순,김종희 한국세라믹학회 2001 세라미스트 Vol.4 No.4

조절이상이 성공적으로 치료된 어린이에 대한 1년 후의 추적검사

신효순,육도진,성덕용,박상철,이선행 한국안광학회 2010 한국안광학회지 Vol.15 No.2

Purpose: The purpose of this study is to evaluate the long-term stability of the improved symptoms and accommodative functions after completion of accommodative therapy. Methods: Seven children (mean age±SD: 12±1.41 years) who were successfully treated with a vision therapy program for either accommodative insufficiency or infacility were followed for 1 year. The visual symptoms of the subjects were measured by the College of Optometrists in Vision Development Quality of Life (COVD-QOL) checklist, and this was followed by measurement of the monocular and binocular accommodative facility with ±2.00 D flipper lens. Results: The mean visual symptoms at the 1 year follow-up examination (15.14±8.59) showed a small increase, but there was no significant difference (p=0.446) from post-therapy (11.86±7.22). There was small regression in the monocular (left eye, 13.86±3.93 cpm) and binocular (11.14±3.13 cpm) accommodative facility at the 1 year follow-up examination, but there were no significant different from the monocular (15.86±4.14 cpm, p=0.147) and binocular (13.21±3.76 cpm, p=0.066) accommodative facility measurements at post-therapy. Also, every subject met the normative values of 7 cpm for monocular accommodative facility and 5 cpm for binocular accommodative facility in the long-term. Conclusions: There was long-term maintenance of the improved visual symptoms and accommodative functions, and so it is clear that the positive therapeutic effects persist with accommodative therapy. 목적: 조절이상에 대한 치료가 완료된 어린이에 대해 장기간의 추적 관찰을 함으로써 치료직후에 향상된 눈증상 과 조절기능이 지속되는지의 여부를 확인하고자 하였다. 방법: 조절부족이나 조절난이가 있는 조절이상자에 대해 12 주 동안 비전세라피 프로그램을 실시한 결과 치료가 성공적으로 이루어진 남여 7명(평균 나이±SD, 12±1.41세)을 대상으로 1년이 경과한 후에 설문지를 사용하여 눈증상을 평가한 후 ±2.00 D 플리퍼 렌즈로 단안 및 양안의 조절 용이를 측정하였다. 결과: 치료 프로그램이 완료되고 1년이 경과한 다음 College of Optometrists in Vision Development Quality of Life(COVD-QOL)로 평가한 평균 눈증상은 15.14±8.53점으로 치료 직후의 11.86±7.60점 보다 작은 증가를 보였으나 유의하지 않았다(p=0.176). 그리고 단안(왼쪽 눈) 및 양안의 평균 조절용이 측정값도 각 각 13.86±3.93 cpm과 11.14±3.13 cpm으로 치료 직후의 15.86±4.14 cpm(p=0.147)과 13.21±3.76 cpm(p=0.066)보 다 작게 감소하였으나 유의하지는 않았으며, 대상자 모두에서 단안 및 양안 조절용이의 정상값인 7 cpm 이상과 5 cpm 이상을 각각 만족하였다. 결론: 장기간의 추적검사를 통해 치료 프로그램 직후에 향상된 눈증상과 조절기능이 여전히 지속되는 것을 볼 수 있었고, 따라서 조절이상에 대한 비전세라피의 치료효과가 장기적임을 확인하였다.