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Sn-Ag-Cu-In-(Mn, Pd) 무연솔더의 솔더링성과 BGA 접합부 신뢰성
장재원,유아미,이종현,이창우,김준기,Jang, Jae-Won,Yu, A-Mi,Lee, Jong-Hyun,Lee, Chang-Woo,Kim, Jun-Ki 한국마이크로전자및패키징학회 2013 마이크로전자 및 패키징학회지 Vol.20 No.3
Sn-3.0Ag-0.5Cu 무연솔더에서 Ag 함량의 감소는 기계적 충격 신뢰성 향상에 도움이 되는 반면 솔더링성을 저하시키는 것으로 알려져 있다. 본 연구에서는 저 Ag함유 무연솔더의 솔더링성 향상을 위해 In을 첨가한 Sn-1.2Ag-0.7Cu-0.4In 4원계 조성과 여기에 미량의 Mn 및 Pd을 첨가한 무연솔더 조성에 대하여 솔더 젖음성을 평가하고, 보드 레벨 BGA 패키지의 열싸이클링 및 기계적 충격 신뢰성을 평가하였다. Sn-1.2Ag-0.7Cu 조성에 0.4 wt% In을 첨가한 합금의 젖음성은 Sn-3.0Ag-0.5Cu에 근접한 수준으로 향상되었으나, 패키지의 열싸이클링 신뢰성은 Sn-3.0Ag-0.5Cu에 미치지 못하는 것으로 나타났다. Sn-1.2Ag-0.7Cu-0.4In 조성에 0.03 wt% Pd의 첨가는 솔더 젖음성 및 패키지 신뢰성을 저하시킨 반면에 0.1 wt% Mn을 첨가한 합금은 특히 기계적 충격 신뢰성이 Sn-3.0Ag-0.5Cu는 물론 Sn-1.0Ag-0.5Cu보다도 우수한 수준으로 향상되었는데, 이는 Mn 첨가가 합금의 모듈러스를 감소시킨 데에 기인하는 것으로 생각된다. Although the lowering of Ag content in Sn-3.0Ag-0.5Cu is known to improve the mechanical shock reliability of the solder joint, it is also known to be detrimental to the solderbility. In this study, the quaternary alloying effect of In and the minor alloying effects of Mn and Pd on the solderability, thermal cycling and mechanical shock reliabilities of the low Ag content Sn-1.2Ag-0.7Cu solder were investigated using board-level BGA packages. The solderability of Sn-1.2Ag-0.7Cu-0.4In was proved to be comparable to that of Sn-3.0Ag-0.5Cu but its thermal cycling reliability was inferior to that of Sn-3.0Ag-0.5Cu. While the 0.03 wt% Pd addition to the Sn-1.2Ag-0.7Cu-0.4In decreased the solderability and reliabilities of solder joint, the 0.1 wt% Mn addition was proved to be beneficial especially for the mechanical shock reliability compared to those of Sn-3.0Ag-0.5Cu and Sn-1.0Ag-0.5Cu compositions. It was considered to be due that the Mn addition decreased the Young's modulus of low Ag content Pb-free solders.
Ball Grid Array 보드 어셈블리의 동적굽힘 신뢰성에 미치는 언더필의 영향
장재원,방정환,유세훈,김목순,김준기,Jang, Jae-Won,Bang, Jung-Hwan,Yoo, Se-Hoon,Kim, Mok-Soon,Kim, Jun-Ki 한국재료학회 2011 한국재료학회지 Vol.21 No.12
In this paper, the effects of conventional and newly developed elastomer modified underfill materials on the mechanical shock reliability of BGA board assembly were studied for application in mobile electronics. The mechanical shock reliability was evaluated through a three point dynamic bending test proposed by Motorola. The thermal properties of the underfills were measured by a DSC machine. Through the DSC results, the curing condition of the underfills was selected. Two types of underfills showed similar curing behavior. During the dynamic bending reliability test, the strain of the PCB was step increased from 0.2% to 1.5% until the failure circuit was detected at a 50 kHz sampling rate. The dynamic bending reliability of BGA board assembly using elastomer modified underfill was found to be superior to that of conventional underfill. From mechanical and microstructure analyses, the disturbance of crack propagation by the presence of submicron elastomer particles was considered to be mainly responsible for that result rather than the shear strength or elastic modulus of underfill joint.
장재원,노지애,김현중,홍정수,배영춘,김동진,Jang, Jae-won,Roh, Ji-ae,Kim, Hyun-joong,Hong, Jung-soo,Bae, Young-chun,Kim, Dong-jin 대한한방내과학회 2017 大韓韓方內科學會誌 Vol.38 No.2
Objectives: The purpose of this clinical case report is to describe the efficacy of Korean medicine in the treatment of vasovagal syncope. Methods: The patient was treated with acupuncture, pharmacopuncture, and herbal medicine. The symptoms (headache, palpitation, sweating, flushing, weakness, coldness) of the patient were observed. Results: After the treatment, the patient's symptoms improved, but more treatments were required. Conclusion: This study can add to understanding of the effect of Korean medicine on vasovagal syncope.
장재원(Jae-Won Jang),김형규(Hyung-Kyu Kim),이순복(Soon-Bok Lee) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11
A complete contact problem in bonded condition is analyzed using a combined experimental-numerical approach. Al and Cu alloys are considered for material combination of the punch and substrate. As for the punch angle, 120 and 135 degrees are used. The finite element (FE) models are validated by comparison of displacement distributions obtained by FE analysis and moire experiment. Generalized stress intensity factors are evaluated using the validated FE models. Stress components around the sharp edges calculated using the FE models are compared with those obtained from an asymptotic analysis.
장재원(Jae-Won Jang),김형규(Hyung-Kyu Kim),이순복(Soon-Bok Lee) 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12
In Part II, finite element analysis (FEA) of a complete contact problem is done following the theoretical analysis of Part I. Al and Cu alloys are considered for material combination of the punch and substrate. As for the punch angle, 90°, 120°, 135° and 150° are used. Generalized stress intensity factors (GSIF) are evaluated with using the mode decoupling angles developed in Part I. The GSIFs are also used to obtain the normalization parameters of the distance and applied load. This paper is end up with the comparison of the FEA and theoretical results of the stress field in the vicinity of the contact corner.