Sn-3.0 Ag-0.5 Cu/OSP 무연솔더 접합계면의 접합강도 변화에 따른 전자부품 열충격 싸이클 최적화

홍원식,김휘성,송병석,김광배,Hong, Won-Sik,Kim, Whee-Sung,Song, Byeong-Suk,Kim, Kwang-Bae 한국재료학회 2007 한국재료학회지 Vol.17 No.3

When the electronics are tested with thermal shock for Pb-free solder joint reliability, there are temperature conditions with use environment but number of cycles for test don't clearly exist. To obtain the long term reliability data, electronic companies have spent the cost and times. Therefore this studies show the test method and number of thermal shock cycles for evaluating the solder joint reliability of electronic components and also research bonding strength variation with formation and growth of intermetallic compounds (IMC). SMD (surface mount device) 3216 chip resistor and 44 pin QFP (quad flat package) was utilized for experiments and each components were soldered with Sn-40Pb and Sn-3.0 Ag-0.5 Cu solder on the FR-4 PCB(printed circuit board) using by reflow soldering process. To reliability evaluation, thermal shock test was conducted between $-40^{\circ}C\;and\;+125^{\circ}C$ for 2,000 cycles, 10 minute dwell time, respectively. Also we analyzed the IMCs of solder joint using by SEM and EDX. To compare with bonding strength, resistor and QFP were tested shear strength and $45^{\circ}$ lead pull strength, respectively. From these results, optimized number of cycles was proposed with variation of bonding strength under thermal shock.

여말 영남지역 포은학파와 경재 홍로

홍원식(Hong Won-Sik) 동아인문학회 2014 동아인문학 Vol.27 No.-

포은 정몽주가 우리나라의 도학과 리학을 열었으며, 그것은 야은길재를 거쳐 한훤당 김굉필로 이어졌다는 것이 조선시대에는 정설처럼 받아들여졌다. 그런데 포은과 야은간의 학맥 전승 관계를 뒷받침해 줄 자료가 뚜렷이 없어서 늘 논란의 대상이 되기도 하였다. 그런데 새롭게 발굴된 <백원첩>을 통해 포은과 야은 두 사람간의 학맥 관계를 확인할 수 있음과 더불어 당시 포은의 동향인 영남 북부 일대에 그의 절의정신을 이은 학맥과 학파가 존재했음도 확인할 수 있었다. 그리고 그 가운데 한 대표적인 인물이 경재 홍로이다. 그는 포은의 문하에서 공부한 뒤 고려 멸망을 맞아 자진순절함으로써 정치적 운명을 같이하였으며, 몇몇 남은 시문 등을 통해 성리학에 대한 조예와 정통 주자학의 입장에 서 있었음을 밝혔다. It is allowed like orthodoxy in the Joseon dynasty that Poeun Jeong Mong-Ju had opened Dohak and Lihak of our country, and it had led to Handhweondang Kim Going-Pil through Yaeun Gil-Jae. By the way, for the reason there are not data which supports the transmission of academic genealogy between Poeun and Yaeun, the orthodoxy is a controversial matter. Through Baekwoncheop whcih is newly excavated, I can identify academic genealogy between Poeun and Yaeun, and can do academic genealogy and school which is descended from poeun’s spirit of loyalty in northern Yeongnam region. The representative man is Gyeongjae Hong-Ro. After he studies under Poeun, he shares political fate with poeun through dying for himself. And he showed orthodox position of Zhuzixue through remaining poetry.

국방 전자장비의 무연솔더 접합 신뢰성 검증기준 개발 가이드라인

홍원식,구기영,황운희,Hong, Won-Sik,Goo, Gi-Young,Hwang, Un-Hee 대한용접접합학회 2012 대한용접·접합학회지 Vol.30 No.3

자동차 전장제품의 무연솔더 적용기술 및 솔더 접합부 열화거동

홍원식,오철민,Hong, Won Sik,Oh, Chul Min 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.3

Due to ELV banning, automotive electronics cannot use four kinds of heavy metal element (Pb, Hg, Cd, $Cr^{6+}$) from 2016. Therefore, this study was focused on degradation characteristics of Sn-3.0Ag-0.5Cu Lead-free solder joint with OSP and ENIG finsh under various reliability assessment method, as like to thermal shock test and high temeprature/high humidity test with test duration for cabin electronics. Also, we compared bonding strength degradation to other advanced research results of electronic control unit for engine room because of difference service temperature with mount location in automotive. Whisker growth phenomenon and mitigation method which were essentially consideration items for Pb-free car electronics were examined. Conformal coating is a strong candidate for mitigating whisker growth in automotive electronics. Necessary condition to adapt Pb-free in car electronics was shown.

전기적 및 전기화학적 특성 측정을 이용한 전자제품 신뢰성평가

홍원식,오철민,박노창,송병석,정승부,Hong, Won-Sik,Oh, Chul-Min,Park, Noh-Chang,Song, Byung-Suk,Jung, Seung-Boo 대한용접접합학회 2007 대한용접·접합학회지 Vol.25 No.2

OSP 표면처리의 열적 열화에 따른 Cu/SnAgCu 접합부의 접합강도

홍원식,정재성,오철민,Hong, Won-Sik,Jung, Jae-Seong,Oh, Chul-Min 한국마이크로전자및패키징학회 2012 마이크로전자 및 패키징학회지 Vol.19 No.1

무연 리플로우 공정 횟수에 따른 organic solderability preservative(OSP) 표면처리 두께변화 및 열화현상을 분석하였다. 무연솔더 접합부의 접합강도에 미치는 OSP 표면처리의 열화특성을 SnPb 표면처리 경우와 비교하여 조사하였다. 또한 리플로우 pass에 따른 무연솔더 접합강도 열화분석을 위해 OSP 및 SnPb 표면처리된 FR-4 재질 PCB를 각각 1-6회 리플로우 처리하였다. 이후 각 리플로우를 거친 PCB 위에 2012 칩 저항기를 실장한 후 접합강도 변화를 측정하였다. 그 결과, 리플로우 공정 중 열 노출에 의해 OSP 코팅두께가 감소되는 것이 관찰되었고, 코팅두께의 변화 및 OSP 코팅 층의 산화를 유발함으로써, 솔더의 젖음성이 감소될 수 있음을 확인할 수 있었다. OSP 열화에 따른 솔더 접합강도는 SnPb 표리처리시 평균 62.2 N 이였으며, OSP의 경우는 약 58.1 N 이였다. 리플로우 공정 노출에 따라 OSP 코팅 층은 열분해 되지만, 솔더 접합부의 접합강도 측면에서는 산업적으로 적용 가능성을 확인할 수 있었다. Bonding strength of Sn-3.0Ag-0.5Cu solder joint due to degradation characteristic of OSP surface finish was investigated, compared with SnPb finish. The thickness variation and degradation mechanism of organic solderability preservative(OSP) coating were also analyzed with the number of reflow process. To analyze the degradation degree of solder joint strength, FR-4 PCB coated with OSP and SnPb were experienced preheat treatment as a function of reflow number from 1st to 6th pass, respectively. After 2012 chip resistors were soldered with Sn-3.0Ag-0.5Cu on the pre-heated PCB, the shear strength of solder joints was measured. The thickness of OSP increased with increase of the number of reflow pass by thermal degradation during the reflow process. It was also observed that the preservation effect of OSP decreased due to OSP degradation which led Cu pad oxidation. The mean shear strength of solder joints formed on the Cu pads finished with OSP and SnPb were 58.1 N and 62.2 N, respectively, through the pre-heating of 6 times. Although OSP was degraded with reflow process, the feasibility of its application was proven.

금속 이온 마이그레이션의 해석적 방법

홍원식,정승부,김광배,Hong Won-Sik,Jung Seung-Boo,Kim Kwang-Bae 대한용접접합학회 2005 대한용접·접합학회지 Vol.23 No.2

SnAgCu계 무연솔더의 전기화학적 반응에 따른 타펠 특성

홍원식,김광배,Hong Won Sik,Kim Kwang-Bae 한국재료학회 2005 한국재료학회지 Vol.15 No.8

Recently European Council(EU) published the RoHS(restriction of the use of certain hazardous substances in electrical and electronic equipment) which is prohibit the use of Pb, Hg, Cd, $Cr^{+6}$, PBB or PBDE in the electrical and electronic equipments. So EU member States shall ensure that, from 1 July 2006, new electrical and electronic equipment put on the market does not contain 6 hazardous substances. The one of the most important in electronics manufacturing process is soldering. Soldering process use the chemical substances which are applied in fluxing and cleaning processes and it can generate the malfunction of electronics caused by corrosion in the fields conditions. Therefore this study researched on the polarization and Tafel properties of Sn40Pb and Sn3.0Ag0.5Cu(SAC) solder based on the electrochemical theory. We prepared SnPb specimens which was aged in $150^{\circ}C,\;180^{\circ}C$ for 15 minutes ana Sn3.0Ag0.5Cu specimens that was aged in $180^{\circ}C,\;220^{\circ}C$ for 10 minutes. Experimental polarization curves were measured in distilled ionized water and $3.5 wt\%$, 1 mole NaCl electrolyte of $40^{\circ}C$, pH 7.5. Ag/AgCl and graphite were utilized by reference and counter electrode, respectively. To observe the electrochemical reaction, polarization test was conducted from -250 mV to +250 mV. From the polarization curves that were composed of anodic and cathodic curves, we obtained Tafel slop, reversible electrode potential(Ecorr) and exchange current density(Icorr). In these results, corrosion rate for two specimen were compared Sn3.0Ag0.5Cu with SnPb solders

한의사가 읽어 본 "소설 동의보감"의 문제

홍원식,Hong, Won-Sik 대한출판문화협회 1991 출판저널 Vol.89 No.-

허준이 한의학사상 주목할 만한 해부학자는 아니다. 그런데 이 소설은, 도처에서 극적 묘사를 통해 해부학적 지식이야말로 한의학이 지향해야 할 방향이고 당위이며, 그전의 해부학이 허준의 시기에 이르러 크게 발전했다는 식의 인식을 독자들에게 심어주고 있다.

PCB의 금속 이온 마이그레이션 현상에 관한 연구

홍원식,강보철,송병석,김광배,Hong Won Sik,Kang Bo-Chul,Song Byeong Suk,Kim Kwang-Bae 한국재료학회 2005 한국재료학회지 Vol.15 No.1

Recently a lots of problems have observed in high densified and high integrated electronic components. One of them is ion migration phenomena, which induce the electrical short of electrical circuit. ion migration phenomena has been observed in the field of exposing the specific environment and using for a long tin e. This study was evaluated the generation time of ion migration and was investigated properly test method through water drop test and high temperature high humidity test. Also we observed direct causes and confirmed generation mechanism of dendritic growth as we reproduced the ion migration phenomena. We utilized PCB(printed circuit board) having a comb pattern as follows 0.5, 1.0, 2.0 mm pattern distance. Cu, SnPb and Au were electroplated on the comb pattern. 6.5 V and 15 V were applied in the comb pattern and then we measured the electrical short time causing by ion migration. In these results, we examined a difference of ion migration time depending on pattern materials, applied voltage and pattern spacing of PCB conductor.