Solder Bump Formation by Ni / Au Electroless Plating for Flip Chip Packaging

조민교,오무형,이원해,박종완 대한전자공학회 1996 대한전자공학회 학술대회 Vol.1996 No.1

Flip Chip의 Solder Bump 형성을 위한 Ni/Au 무전해 도금 공정 연구

조민교,오무형,이원해,박종완,Jo, Min-Gyo,O, Mu-Hyeong,Lee, Won-Hae,Park, Jong-Wan 한국재료학회 1996 한국재료학회지 Vol.6 No.7

Flip chip bonding에 무전해도금기술을 적용하여 solder bumper형성의 최적 조건을 규명하였다. 시편은 AI 패턴된 4 inch Si 웨이퍼를 사용하고, 활성화 처리시 zincate 용액을 사용하였으며, 무전해 도금은 Ni-P 도금액고 Au immersion 용액을 사용하였다. 활성화 물질의 AI 침식정도 및 Zn 석출 정도를 알아보기 위하여 EDS측정을 하였고, 각 공전에서의 표면형상을 알아보기 위해 SEM 분석을 하였다. 열처리 후 금도금층의 주 결정성장 방향은 XRD를 이용하여 측정하였다. 산처리에서 질산과 황산 중 질산에 의한 산화막제거 정도가 더 우수하게 나타났다. 활성화 처리시 zincate 용액을 희석시킬수록 입자 크기가 미세해 지고, 활성화 물질은 pH 13-13.5, 상온, 농도 15-25%의조건에서 크기가 작은 Zn 활성화 물질이 균일하게 분포하였다. Ni과 Auan전해도금 속도는 온도와 pH가 증가할수록 증가하였다. Ni 무전해 도금 조건은 pH 4.5, 온도 $90^{\circ}C$, 시간 20분이며, Au 무전해 도금조건은 pH7, 온도 $80^{\circ}C$, 시간 10분이었다. 상온에서 $400^{\circ}C$까지 30분동안 열처리 한 후 금도금막의 결정 방향은 pH 7, 온도 $80^{\circ}C$, 시간 10분이었다. 상온에서 $400^{\circ}C$까지 30분 동안 열처리 한 후 금도금막의 결정 방향은 pH 7에서 (111), pH 9에서는 (200)과 (111)이 주 peak로 나타났으며, 열처리에 의한 결정 방향의 변화는 없었다. 전체 공정에서 최종적인 표면 형상에 영향을 주는 단계는 활성화 처리로서 flip chip의 bonding layer형성에 가장 중요한 요소임을 알 수 있었다.보다 자생지(自生地)에서 높은 함량(含量)을 보였다. 5. 무기성분함양(無機成分含量)의 차이(差異)는 K의 경우(境遇) 자생지(自生地)에서 보다 재배지(栽培地)에서 평균적(平均的)으로 10배이상(倍以上) 정도(程度) 높은 함량(含量)의 차이(差異)를 보였으나 Mn, Zn, Na, Cu 등(等)은 일정(一定)한 경향(傾向)을 보이지 않는 것으로 나타났다. 6. 유리(遊離) 아미노산(酸)의 함량(含量)은 자생지(自生地은)보다 재배지(栽培地)에서 전반적(全般的)으로 높은 함량(含量)을 나타내었고, 특(特)히 Arginine은 다른 성분(成分)들과 비교(比較)해 볼 때 가장 높은 조성(組成)의 차이(差異)를 나타내었다. 7. 야생(野生)더덕과 재배(栽培)더덕의 정유성분수율(精油成分收率)은 자생지재배(自生地栽培)에서는 모두 0.004% 였고 재배지(栽培地)에서는 야생(野生)더덕이 0.005%였다. 8. 더덕의 재배장소(栽培場所)에 따른 향기성분(香氣成分)은 총(總) 21종(種)이었으며 自生地(自生地)에서 야생(野生)더덕은 16종(種), 재배(栽培)더덕은 18종(種)이었고, 재배지(栽培地)에서 야생(野生) 더덕은 14종(種), 재배(栽培)더덕은 20(種)이었다. 9. Trans-2-hexanol은 야생(野生)더덕의 자생지(自生地) 재배(栽培)에서 피이크 면적(面積) 당(當) 50.3%, 재배지(栽培地)에서 피이크 면적(面積) 당(當) 43.3%를 보였으며 amylalcohol, furfuryl acetate, 2-methoxy-4-vinyl phenol(MVP)는 재배(栽培)더덕에서만 확인(確認)되었다.는 KI, BMI와 유의적인 양의 상관관계를 보였고 (p<0.01), HCL-C은 비체중, BMI, LBM, TBM와 유의적인 음의 상관관계를 보였으며, (p<0.01), KI, SBP와도 음의 상관관계를 보였다. (p<0.05), LCL-C는 KI와 유의적이인 양의 Electroless plating technique was utilized to flip chip bonding to improve surface mount characteristics. Each step of plating procedure was studied in terms pf pH, plating temperature and plating time. Al patterned 4 inch Si wafers were used as substrstes and zincate was used as an activation solution. Heat treatment was carried out for all the specimens in the temperature range from room temperature to $400^{\circ}C$ for $30^{\circ}C$ minutes in a vacuum furnace. Homogeneous distribution of Zn particles of size was obtained by the zincate treatment with pH 13 ~ 13.5, solution concentration of 15 ~ 25% at room temperature. The plating rates for both Ni-P and Au electroless plating steps increased with increasing the plating temperature and pH. The main crystallization planes of the plated Au were found to be (111) a pH 7 and (200) and (111) at pH 9 independent of the annealing temperature.

반도체 패키지 기판용 Ni-less 표면처리 기술 개발동향

조민교,조진기,김경민,김성용,한덕곤,성태현 한국마이크로전자및패키징학회 2023 마이크로전자 및 패키징학회지 Vol.30 No.1

Recently, System in Packaging(SIP) technology needs to meet high frequency (5G and more) communication technology and fine pitch surface treatment. The conventional Electroless Ni/Immersion Au plating(ENIG) is not suitable for high frequency range because of magnetic properties are increasing the transmission loss. Without nickel plating layer, the pattern and pad reliability level must be meet the condition. In this review paper, we investigated research trends on Ni-less surface treatment technology for high-frequency communication and frequency characteristics according to materials. 최근 SIP (System in Packaging) 기술은 고주파(5G 이상) 통신 및 미세 피치 회로 특성을 만족해야 한다. 기존ENIG (Electroless Ni/Immersion Au Plating) 표면처리는 전송 손실이 증가하여 고주파에 적합하지 않으므로, 니켈 도금층이 없어도 패턴 및 패드의 신뢰성 수준을 만족시킬 수 있는 표면 처리 기술이 검토되고 있다. 본 논문에서는 고주파 통신 대응을 위한 Ni-less 표면처리기술과 소재에 따른 주파수 특성 등에 대한 연구 동향을 조사하였다.

Dynamic Analyses of Fluctuating Bearing Forces on Worm Gears of Speed Reducers

조민교,김철 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.2

The objective of this work is to develop an efficient multi-body model of a worm gear reducer in order to predict fluctuating reaction forces at supporting bearings. Noise and vibration in a worm gear reducer system takes place primarily due to axis misalignment, unsteady motor power supply and the twist of a shaft. The dynamical interactions among input and output shafts together with equivalent stiffness, contacting worm and worm-gear and supporting bearings were included in this multi-body dynamic model. The fluctuating reactive forces on the supporting bearings of single- and double-axis reducers were computed for four alignment angles of axes by the model. The fluctuation force on supporting bearings due to misalignment of axes is a major factor for the noise and vibration of a worm gear reducer. The results demonstrate convincingly that a double-axis type worn gear set is more vulnerable to axis misalignment compared to a single-axis type. Therefore, a single-axis reducer fits for a powered wheelchair.

전동휠체어 웜기어 감속기의 불안정한 베어링 지지반력의 동역학적 해석

조민교(Minkyo Cho),김준형(Junhyoung Kim),김철(Cheol Kim) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

The objective of this paper is to present the development of an efficient multi-body model to predict fluctuating reaction forces at supporting bearings. Major noise and vibration in a worm gear reducer system takes place due to the axis misalignment and unsteady motor power supply. In addition, noise and vibration are also related to the torsional deformation of a shaft. The dynamic interactions among input/output shafts with an equivalent stiffness, contacting worm and gear, and bearings, were considered in the flexible multi-body model. and the fluctuating reactive forces on bearings were calculated. The fluctuation force on supporting bearings due to misalignment of axes is a major factor for the noise and vibration of a worm gear reducer.

변속기 하우징의 보강 위치선정을 위한 위상최적화

조민교(Minkyo Cho),김철(Cheol Kim),한병기(Byoungkee Han) 한국자동차공학회 2009 한국자동차공학회 부문종합 학술대회 Vol.2009 No.4

The objective of the paper is to present the development and application of an topology optimization method based on the improved density distribution method. With this improved method, the optimum design can be obtained by manipulating sized and frontiers of material territories which are lumps of material with specified properties. The developed method was successfully applied to the topology optimization of a car transmission housing in order to reduce the gear rattling noise. An innovative flexible multi-body dynamic model was newly developed to predict fluctuating contacting loads on surfaces of two meshing gears and their accurate rattling impact forces when unloaded, which fluctuate within a tooth backlash at each gear speed due to the irregular combustion torque of internal combustion engines, and the resulting noise radiated from a manual gearbox due to the gear rattle using MSC/ADAMS and Hyperwork.

래틀링 소음원인 변속기 축 및 치면의 시간 변화력 계산을 위한 축의 등가강성 변환기법

조민교(Minkyo Cho),한병기(Byoungkee Han),김철(Cheol Kim),임채홍(Chaehong Lim),김정준(Jungjun  Kim) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The objective of this paper is to present the development and the application of an efficient flexible multi-body dynamic model to predict fluctuating contacting loads on the surfaces of two meshing gears and their accurate rattling impact forces when unloaded, which fluctuate within tooth backlash at each gear stage due to the irregular combustion torque of internal combustion engines, and resulting noise radiated from manual gearboxes due to the gear rattle using ADAMS. Three types of approaches were performed and compared: modeling the gear and shaft as a full rigid-body: using a flexible shaft based on FEA; the substitution of a shaft to many torsion springs. The method of the torsion springs were shown to be very efficient. The computation time was reduced and the accuracy was almost the same as that of a flexible shaft based on FEA.

수동변속기의 다물체 동역학모델링과 작용력계산에 의한 래틀현상 예측

조민교(Minkyo Cho),한병기(Byoungkee Han),김철(Cheol Kim),임채홍(Chaehong Lim),김정준(Jungjun Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

The objective of this paper is to present the development of an efficient multi-body model to predict the noise radiated from manual gearboxes due to gear rattle using multi-body dynamics. Major noises in a gear driving system are rattle and whine due to transmission error and backlash. These noises are related to the torsional deformation of a transmission shaft. The dynamic interactions among the gearbox components including a flywheel, input/output shafts with an equivalent stiffness, contacting gear-pairs, and bearings, are considered in modeling by flexible multi-body techniques to account for shaft torsion. Fluctuating forces on a gear driving system were calculated by the reactive forces on bearings and were applied to predict more accurate rattle conditions in a frequency domain.

래틀소음을 고려한 수동변속기 하우징의 위상최적설계

조민교(Minkyo Cho),김철(Cheol Kim),한병기(Byoungkee Han),임채홍(Chaehong Lim),김정준(Jungjun Kim) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

PREDICTION OF VIBRATING FORCES ON MESHING GEARS FOR A GEAR RATTLE USING A NEW MULTI-BODY DYNAMIC MODEL

한병기,조민교,임채홍,김정준,김철 한국자동차공학회 2009 International journal of automotive technology Vol.10 No.4

An efficient multibody dynamic model was developed to predict the vibrating transmitted gear forces of loaded and unloaded pairs of helical gears simultaneously at all speeds. The model can also calculate the bearing forces of a manual transmission that, in turn, may be converted to rattling noises. The bending of meshing gear teeth and torsional flexibility of transmission shafts were considered and embodied effectively in the multibody dynamic model by calculating the tooth bending stiffness and adding a torsion spring on a shaft section between two gears, respectively. The reactive forces on teeth and bearings were calculated and compared using three different models that were developed for this study - an equivalent model, a rigid-body model, and a frequency-based model. The equivalent model took only 58% computation time, compared to the frequency-based method, even though the two showed very similar results. An efficient multibody dynamic model was developed to predict the vibrating transmitted gear forces of loaded and unloaded pairs of helical gears simultaneously at all speeds. The model can also calculate the bearing forces of a manual transmission that, in turn, may be converted to rattling noises. The bending of meshing gear teeth and torsional flexibility of transmission shafts were considered and embodied effectively in the multibody dynamic model by calculating the tooth bending stiffness and adding a torsion spring on a shaft section between two gears, respectively. The reactive forces on teeth and bearings were calculated and compared using three different models that were developed for this study - an equivalent model, a rigid-body model, and a frequency-based model. The equivalent model took only 58% computation time, compared to the frequency-based method, even though the two showed very similar results.