납착 방법이 치과용 금속의 성상에 미치는 영향에 관한 연구

김철형,송영균,이종혁 대한치과보철학회 2012 대한치과보철학회지 Vol.50 No.1

연구 목적: 본 연구는 치과영역에서 많이 사용되는 비귀금속 합금인 니켈-크롬 합금을 산소-아세틸렌 불꽃 납착법과 적외선 용접법을 이용해 용접하고 용접부 및 그 주변을 광학 현미경과 EPMA (Electron Probe Micro Analyzer, 전자미세현미분석기)를 통해 관찰하여 용접방법이 금속의 성상(性狀)에 미치는 영향을 조사하였다. 연구 재료 및 방법:니켈-크롬 합금을 이용하여 3.0 mm 직경, 30 mm 길이의 시편을 제작하였다. 시편은 산소-아세틸렌 불꽃 납착법, 적외선 용접법의 두 개의 그룹으로 분류하였다(n = 4). 시편을 low-speed disc로 자른 후 각각을 산소-아세틸렌 토치와 적외선 용접기를 이용해 용접하였다. 용접과 마무리 후에 시편을 광학현미경으로 용접부, 5 mm 떨어진 지점, 10 mm 떨어진 지점의 3개 부위에서 관찰하고EPMA를 이용하여 분석하였다. 결과: 광학 현미경 관찰 결과 용접부에서는 두 방법 모두 다수의 파절선이 관찰되었고, 10.0 mm 떨어진 거리에서는 두 방법 모두 시편의 표면에서 파절선이 발견되지 않았으나 5.0 mm 떨어진 거리에서는 적외선 용접법에서는 시편의 표면이 다소 거칠기는 했으나 파절선은 발견되지 않았고 산소-아세틸렌 불꽃 납착 표면에서는 다수의 파절선이 관찰되었다. EPMA분석에서 적외선 용접법에 의한 방법에서는 용접부위, 5.0 mm 떨어진 부위, 10.0 mm 떨어진 부위 모두에서 시편 금속의 구성성분 비율이 제조사의 구성성분 비율과 10.0%이내의 오차를 나타내었고, 산소-아세틸렌 불꽃 납착법에서는 5.0, 10.0 mm에서는 시편금속의 구성성분이 10.0%이내의 오차를 나타내었으나, 납착 부위에서는 Ni만이 검출되어 적외선 용접법과는 차이를 나타내었다. 이와 같은 분석결과를 살펴 볼 때 적외선 용접을 시행한 시편의 구성 성분이 모금속의 성분과 유사한 것을 알 수 있었다. 결론: 이상의 결과로 산소-아세틸렌 불꽃 납착법보다 적외선 용접법을 이용할 때, 금속의 결함 및 성분의 변화가 적어서 좀 더 우수한 금속 보철물의 제작이 가능할 것으로 사료된다. PURPOSE. The purpose of this study was to compare Ni-Cr alloy property of gas-oxygen torch soldering and infrared welding using optical microscope and Electron Probe Micro Analyzer (EPMA). MATERIALS AND METHODS. Ni-Cr alloys were casted for specimens. Specimens had 3.0 mm diameter, 30.0 mm length and were divided into two groups. Each group had 4 specimens. One group was for gas-oxygen torch soldering and the other was infrared welding. Specimens were cut with low-speed disc and soldered each other with gas-oxygen torch and infrared machine. After soldering and polishing, specimens were observed at 3 points (soldering point, 5 mm distance point, 10 mm distance point) with optical microscope and analyzed 3 points (soldering point, 5 mm distance point, 10 mm distance point with EPMA. RESULTS. The results of this study were as follows: 1. The observation of gas-oxygen torch soldering at 10 mm distance point under the optical microscope was not founded any specific surface properties, but some crack lines were observed at 5 mm distance and soldering point. 2. There were no crack lines were founded at the observation of infrared welding at 10 mm distance and 5 mm distance points under the optical microscope. However, at the 5 mm distance, the surface was not smooth enough compared with at 10 mm distance point. Some crack lines were observed at the welding point as well. 3. In the EPMA analysis of the gas-oxygen torch soldering, the component of Ni was increased by 4.5%, Cr was increased by 7.5% than that of the Ni-Cr alloy at the 10.0 mm distance. At the 5 mm distance, the component of Ni was decreased by 6.1%, Mo was increased by 9.0% than that of the Ni-Cr alloy but Cr was equally shown at the 5.0 mm distance. Only Ni was shown at the soldering point. 4. In the EPMA analysis of the infrared welding, the component of Ni was increased by 9.1%, Cr was increased by 0.4% than that of the Ni-Cr alloy but Al was equal at the 10.0 mm distance. At the 5 mm distance, the component of Ni was increased by 4.7%, Cr was increased by 4.7% and Al was increased by 0.1% than that of the Ni-Cr alloy. At the welding point, the component of Ni was increased by 8.8%, Cr was increased by 8.2% than that of the Ni-Cr alloy. CONCLUSION.From these results, at the 5 mm distance from the soldering point, the surface of the infrared welding was more smoother than that of the gas-oxygen torch soldering. On the EPMA analysis, the component of the specimens with infrared welding was more similar than that of the gas-oxygen torch soldering compared with the component of the Ni-Cr alloy.

Challenges in Minimizing Copper Dissolution for Lead Free Wave Soldering in Surface Mount Technology Going Towards Green Manufacturing

Mageswaran Arunasalam,Zulkifl le B. Leman,B. T. Hang Tuah B. Baharudin,Shamsuddin B. Sulaiman,Charles Santhakumar Anthony Das 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.2

In surface mount technology, development toward green manufacturing by converting all leaded soldering processes to lead free soldering process has created a lot of challenges mainly in wave soldering process which led to copper dissolution to assemble board causing it to be scrapped if not contained. The paper aims to propose a workable and practical solution to reduce extensive copper dissolution in assemble board and expand the cycle of allowable rework in assemble board. The work was carried out using Six Sigma methodology with defining the problem and research goals, measure the details in various aspects of current process, analyse data to identify potential root cause in a process, improve the process and control the process through experimental approaches. Main factors contributing to copper dissolution were identified and analysed. Total of five factors were identified namely the printed circuit board (PCB) finishing and copper layer construction in PCB, component terminal and led finishing, soldering flux usage and solder alloy composition, environment control with the use of Nitrogen tunnelling and the last factor was on the process itself which was from the in-contact process with molten turbulence soldering or non-contact process with intrusive soldering. Combined controlled factors contributing to minimization of copper dissolution by reducing the direct contact time to molten solder with optimize solder alloy composition and process control was formulated. An increase of sixty percentage of boards with lower copper dissolution going through the lead free wave soldering and rework soldering were obtained, another forty percent reduction of board being scrapped were also obtained with boards going through the molten solder up to triple times.

연결방법에 따른 주조체 변위에 관한 3차원적 비교연구

임장섭,전영찬,정창모,Lim, Jang-Seop,Jeon, Young-Chan,Jeong, Chang-Mo 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.3

This study measured the relative displacements of the five-unit fixed partial dentures as cast with the same fixed partial dentures sectioned and assembled by investment-soldering, solder-ing stand-soldering, and cast-joining techniques A total of fifteen specimens using a type IV gold alloy were one-piece cast as control and then sectioned and assembled five test specimens for each method were prepared. A computerized three dimensional coordinate measuring machine and specially designed cylinder for this study were used. Displacement was defined by six displacement variables for the each of cylinders incorporated in each casting: three component displacements(${\Delta}Lx,\;{\Delta}Ly,\;and\;{\Delta}Lz$) and rotational displacements(${\Delta}{\theta}x,\;{\Delta}{\theta}y,\;{\Delta}{\theta}z$). The global displacement was computed using the mathematical formula ${\Delta}R$ = Global displacement =$\sqrt{{(x'-x)}^2+{(y'-y)}^2+{(z'-z)}^2}$ Under the conditions of this study, the following conclusions were drawn: 1. The investment-soldering group showed the largest mean value of final global displacements, followed by stand-soldering group, cast-joining group and one-piece cast group. However, between the mean values of final global displacement for the cast-joining group and one-piece cast group, there was no significant difference. 2. For investment-soldering and stand-soldering groups, the greater global displacements were recorded in soldering phase than in indexing or investing phase. 3. For one-piece cast group, the displacements occured mostly in the casting phase. And for cast-joining group, there was no significant difference in global displacements among the fabricating procedures. 4. Intercentroidal distance decreased in framework-patterning, solder-indexing, solder-standing, and soldering phases, but increased in investment block-investing and casting phases. 5 Specially designed cylinder for touch-trigger type coordinate measuring machine was validated.

MLCC Solder Joint Property with Vacuum and Hot Air Reflow Soldering Processes

홍원식,김미송,김명인 대한용접접합학회 2021 대한용접·접합학회지 Vol.39 No.4

After the joining of small 1005 and 0603 multilayer ceramic capacitor (MLCC) components for a semiconductor package using Type 4 (T4) and Type 7 (T7) Sn-3.0Ag-0.5Cu (SAC305), T4 Sn-1.0Ag-0.5Cu (SAC105), and T4 Sn-0.3Ag-0.7Cu (SAC0307) solder pastes, the differences between hot air reflow and vacuum soldering processes were compared in terms of void content, shear strength, and microstructure. Results showed that the hot air reflow soldering process exhibited a stable joint with a void content of 5% or less, and the vacuum soldering condition sig- nificantly reduced the void content of the solder joint as the soldering proceeded in a vacuum state. The shear strength of the SAC305 solder joint with the same powder particle size was measured to be greater for the shear strength of the vacuum soldered joint as compared to the reflow process. The vacuum soldering process was effec- tive in removing voids during the void joining process and contributed to an improved joint strength of the solder joint by reducing the void content. When the same soldering process was applied using the 1005 MLCC chip com- ponent, the bonding strength of the T4 SAC305 solder was slightly higher than those of the SAC105 and SAC0307 solders. However, the overall initial bonding strengths were similar. The e ffects of Ag content within 0.3-3.0 wt% on the initial bonding strengths of the solders were judged to be the same. Diverse Cu6Sn5, Ag3Sn, (Ni,Cu,Pd)3Sn4, (Cu,Ni)6Sn5, NiP, and Ni3P intermetalli ccompounds (IMCs) were formed at the interfaces between the electroless nickel/electroless palladium/immersion gold finish substrate and SAC solder joint. The IMC types were constant re- gardless of Ag content and solder type, and the IMCs contributed to the initial solder joint strength.

Effect of soldering techniques and gapdistance on tensile strength of soldered Ni-Cr alloy joint

Lee, Sang-Yeob,Lee, Jong-Hyuk The Korean Academy of Prosthodonitics 2010 The Journal of Advanced Prosthodontics Vol.2 No.4

PURPOSE. The present study was intended to evaluate the effect of soldering techniques with infrared ray and gas torch under different gap distances (0.3 mm and 0.5 mm) on the tensile strength and surface porosity formation in Ni-Cr base metal alloy. MATERIALS AND METHODS. Thirty five dumbbell shaped Ni-Cr alloy specimens were prepared and assigned to 5 groups according to the soldering method and the gap distance. For the soldering methods, gas torch (G group) and infrared ray (IR group) were compared and each group was subdivided by corresponding gap distance (0.3 mm: G3 and IR3, 0.5 mm: G5, IR5). Specimens of the experimental groups were sectioned in the middle with a diamond disk and embedded in solder blocks according to the predetermined distance. As a control group, 7 specimens were prepared without sectioning or soldering. After the soldering procedure, a tensile strength test was performed using universal testing machine at a crosshead speed 1 mm/min. The proportions of porosity on the fractured surface were calculated on the images acquired through the scanning electronic microscope. RESULTS. Every specimen of G3, G5, IR3 and IR5 was fractured on the solder joint area. However, there was no significant difference between the test groups (P > .05). There was a negative correlation between porosity formation and tensile strength in all the specimens in the test groups (P < .05). CONCLUSION. There was no significant difference in ultimate tensile strength of joints and porosity formations between the gas-oxygen torch soldering and infrared ray soldering technique or between the gap distance of 0.3 mm and 0.5 mm.

Sn-3.5Ag-0.7Cu Micro-BCA의 Soldering성 연구

신규식,김문일,정재필,신영의,Kozo Jujimoto 한국마이크로전자및패키징학회 2000 마이크로전자 및 패키징학회지 Vol.7 No.3

직경 0.3 mm의 Sn-37Pb 및 Sn-3.5Ag-0.7Cu 솔더볼을 솔더링 온도와 기판의 이송속도 (conveyer speed)를 변화시켜 가며 리플로 솔더링 하였다. 리플로 솔더링 온도범위는 Sn-37Pb의 경우 220~$240^{\circ}C$, Sn-3.5Ag-0.7Cu의 경우는 230~ $260^{\circ}C$로 하였다. 실험결과, 전단강도 측면에서 최적 솔더링 조건을 Sn-37Pb의 경우 솔더링 온도 및 컨베이어 속도가 각각 $230^{\circ}C$, 0.7~0.8 m/min이고, Sn-3.5Ag-0.7Cu의 경우 각각 $250^{\circ}C$, 0.6 m/min으로 나타났다. 또한 최고 전단강도 값은 Sn-37Pb의 경우는 555 gf 이고 Sn-3.5Ag-0.7Cu의 경우는 617gf이다. 접합계면의 분석결과 Cu6Sn5층의 두께는 Sn-37Pb의 경우는 1.13~1.45 $\mu\textrm{m}$이고 Sn-3.5Ag-0.7Cu의 경우는 2.5~4.3 $\mu\textrm{m}$이다. Sn-37Pb and Sn-3.5Ag-0.7Cu solder balls of 0.3 mm diameter were reflow soldered with the variation of soldering peak temperature and conveyer speed of reflow machine. The peak temperatures far soldering were changed in the range of 220~$240^{\circ}C$ for Sn-37Pb and 230~$260^{\circ}C$ for Sn-3.5Ag-0.7Cu. As the results of experiments, optimum soldering condition for Sn-37Pb was $230^{\circ}C$ of soldering temp., 0.7~0.8 m/min of conveyer speed. The optimum condition for the Sn-3.5Ag-0.7Cu was $250^{\circ}C$ and 0.6 m/min. The maximum shear strength for the soldered joints of Sn-37Pb was 555 gf and of Sn-3.5Ag-0.7Cu was 617 gf. Thickness of the intermetallic compound Cu6Sn5 on the soldered interface was 1.13~1.45 $\mu\textrm{m}$ for Sn-37Pb and 2.5~4.3 $\mu\textrm{m}$ for Sn-3.5Ag-0.7Cu.

Sn-Bi도금 $Sn-3.5\%Ag$ 솔더를 이용한 Capacitor의 저온 솔더링

김미진,조선연,김숙환,정재필,Kim Mi-Jin,Cho Sun-Yun,Kim Sook-Hwan,Jung Jae-Pil 대한용접접합학회 2005 대한용접·접합학회지 Vol.23 No.3

Since lead (Pb)-free solders for electronics have higher melting points than that of eutectic Sn-Pb solder, they need higher soldering temperatures. In order to decrease the soldering temperature we tried to coat Sn-Bi layer on $Sn-3.5\%Ag$ solder by electroplating, which applies the mechanism of transient liquid phase bonding to soldering. During heating Bi will diffuse into the $Sn-3.5\%Ag$ solder and this results in decreasing soldering temperature. As bonding samples, the 1608 capacitor electroplated with Sn, and PCB, its surface was finished with electroless-plated Ni/Au, were selected. The $Sn-95.7\%Bi$ coated Sn-3.5Ag was supplied as a solder between the capacitor and PCB land. The samples were reflowed at $220^{\circ}C$, which was lower than that of normal reflow temperature, $240\~250^{\circ}C$, for the Pb-free. As experimental result, the joint of $Sn-95.7\%Bi$ coated Sn-3.5Ag showed high shear strength. In the as-reflowed state, the shear strength of the coated solder showed 58.8N, whereas those of commercial ones were 37.2N (Sn-37Pb), 31.4N (Sn-3Ag-0.5Cu), and 40.2N (Sn-8Zn-3Bi). After thermal shock of 1000 cycles between $-40^{\circ}C$ and $+125^{\circ}C$, shear strength of the coated solder showed 56.8N, whereas the previous commercial solders were in the range of 32.3N and 45.1N. As the microstructures, in the solder $Ag_3Sn$ intermetallic compound (IMC), and along the bonded interface $Ni_3Sn_4$ IMC were observed.

레이저 마이크로 솔더링과 솔더링 인자

황승준,황성빈,정재필,Hwang, Seung Jun,Hwang, Sung Vin,Jung, Jae Pil 한국마이크로전자및패키징학회 2020 마이크로전자 및 패키징학회지 Vol.27 No.3

In this paper, the principles, characteristics and recent studies of the laser micro soldering are reviewed. The factors which influence laser micro welding and soldering are also included. Laser soldering is a non-contact process that transfers energy to solder joint by a precisely controlled laser beam. In recent electronics industry, the demands for laser soldering are increasing due to bonding for complex circuits and local heating in micro-joint. In laser soldering, there are several important factors like laser absorption, laser power, laser scanning speed, and etc, which affect laser solderability. The laser absorption ratio depends on materials, and each material has different absorption or reflectivity for the laser beam, which requires fine adjustment of the laser beam. Laser types and operating conditions are also important factors for laser soldering performance, and these are also reviewed.

일부 인쇄회로기판 납땜근로자들의 눈, 호흡기, 피부의 증상에 대한 조사연구

유재영,우극현,김진석,함정오,최태성,하봉구,정상재,박신구,김일룡 大韓産業醫學會 2001 대한직업환경의학회지 Vol.13 No.4

목적 : 이 연구는 납점작업자를 대상으로 납점작업으로 유발될 가능성이 높은 눈, 호흡기, 피부 등의 증상호소율 및 노출강도에 따른 관련성을 파악하기위해 수행되었다. 방법 : 연구참가자 146명중 연구목적에 적합한 20명을 제외한 126명을 대상으로 '눈이 가렵고 충혈됨', '코가 가렵거나 파가움', '재채기', '콧물'. '코막힘' , '목이 따끔거림' , '목에 무언가가 걸려있는것 같음' , '갑자기 연속적인 기침을 함' , '운동 시에 다른 사람에 비해 숨이 가쁨', '숨을 쉴 때 쌕쌕하는 소리가 남', '가래가 끓음', '손이나 안면에 가려움을 느낌' , '안면에 여드름이 날' '손이나 안면에 붉은 반점이 남' 등 14가지 증상에 대한 경험유무와 혈중연농도, 납점작업의 건강위험요인에 대한 지식상태 등을 조사하였다. 결과 : 조사된 14가지의 증상 중, '갑자기 연속적인 기침을 함'이 하루 납점시간 4시간 이상인 군아서 4시간 미만인 군보다 유의하게 증상호소율이 높았으며, 다른 증상의 경우 하루 납땜시간에 따라 유의한 결과를 보이지 않았다. 납땜작업의 건강위험요인에 대한 질문에 12.8 %가 플럭스에 의한 건강위험을 지적하였다. 전체 대상자의 평균 혈중연농도는6.05 rg/dL였으며, 히고치는 15.50 rg/dL이었다.결론 : 납땜작업자에게 호흡기 증상의 위험이 높을 가능성이 있으며, 납땜작업의 건강위험에 대한추가적인 연구와 납점작업자들을 대상으로 납점작업에 의해 유발될 수 있는 건강장해에 대한 적극적인교육 및 홍보활동을 필요로 한다. Objectives : This study was conducted to evaluate the prevalence of ocular, respiratory and skin symptoms among solderers and to investigate the relationship between symptom prevalence and exposure intensity. Methods : We analyzed 126 eligible participants out of a population of 146 male solder-ers who completed the symptom questionnaires. Fourteen symptoms including 'itchy and red eyes', 'itchy or prickly nose', 'sneezing', 'rhinorrhea', 'blocked nose', 'prickly throat', 'foreign body sensation in throat', 'sudden bouts of coughing', 'exertional breathlessness', 'wheezing', 'sputum production', 'itchy face or hands', 'acneiform erup-tions on the face' and 'red spots on the face or hands' were contained. Blood lead levels of all the 126 participants were tested and the participants' own assessments of the health risk of soldering were collected. Results : Of the 14 investigated symptoms, 'sudden bouts of coughing' was significantly more prevalent in solderers who worked 4 hours or more a day than those who worked less than 4 hours a day, as for the other symptoms, there were no significant differences in the prevalences related to daily soldering hours. 2.8% of the solderers considered the risk of flux exposure to be serious. The mean blood lead bevel was 6.05 μg/dL (maximum 15.50 μg/dL). Conclusions : Soldering may increase the risk of respiratory symptoms. Further invert tigations on the hazards of soldering processes are warranted and solderers should be educarted on these hazards.

태양전지 모듈의 솔더링 공정에 대한 신뢰성

김성진(S-J Kim),최준영(J-Y Choi),공지현(J-H Kong),문종혁(J-H Moon),이세훈(S-H Lee),심원현(W-H Shim),이은혜(E-H Lee),이은주(E-J Lee),이해석(H-S Lee) 한국태양에너지학회 2011 한국태양에너지학회 학술대회논문집 Vol.2011 No.11

Although PV module manufacturing and its structure are simple,the semi-permanent products can be used out doors for more than twenty years.Therefore it is need to choose proper materials and optimize manufacturing process. This paper suggest that factors of degradation need to be studied to achieve a more understanding of PV module Degradation rates and materia lfailure. Nowadays durability of the PV Module is very important to sustain output safety for obtaining reliability. This paper is about the experiment that soldering uniformity of soldering process and to make least void from soldering process. From This study soldering flux residue and soldering method is main factor to form void blocked soldering uniformity and by using this.