• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2004년도 ISMP Pb-free solders and the PCB technologies related to Pb-free solders
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• pp.1-26
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• 2004

The implementation of Pb-free solder technology is making good progress in electronic industry. Further understanding on fundamental issues on Pb-free solders/processes is required to reduce reliability risk factors of Pb-free solder joints. Several reliability issues including thermal fatigue, impact reliability, IMC growth, spalling, void formation are reviewed for Pb-free solder joints. Several applications of Pb-free technology are discussed, such as Pb-free, CBGA, CuCGA, flip chips, and wafer bumping by IMS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.577-579
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• 2004

Digital hearing aids enclose $6{\sim}8$ tiny components. Those electromechanical components are individually wired by soldering which is a manual labor and sometimes causes components' damage by heating. This paper suggests a PCB design for overcome these problems. Several PCBs are designed and manufactured and circuited to produce ITE(In The Ear) type hearing aids which are inserted in the ear canal. The most optimal size of the PCB design for the ITE hearing aid is presented in this paper.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1012-1015
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• 2004

Digital hearing aids enclose $6{\sim}8$ tiny components. Those electromechanical components are individually wired by soldering which is a manual labor and sometimes causes components' damage by heating. This paper suggests a PCB design for overcome these problems. Several PCBs are designed and manufactured and circuited to produce ITE(In-the-Ear) type hearing aids which are inserted in the ear canal. The most optimal size of the PCB design for the ITE hearing aid is presented in this paper.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2006년도 춘계학술발표회 초록집
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• pp.78-78
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• 2006

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.81-83
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• 2004

최근 대두되고 있는 환경오염문제로 인해 전자산업에서는 전 세계적으로 Pb 솔더에 관한 규제가 진행중에 있다. 이에 Pb free 솔더에 관한 연구가 활발히 진행 중에 있으며 그 중 Sn-Ag계 solder는 유력한 대체 solder로 대두되고 있다. (중략)

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.78-80
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• 2004

현재 전자 부품 실장에 사용되는 솔더 합금들 중에서 Sn-Pb계 솔더는 취급이 용이하고 낮은 가격 및 솔더재로서의 우수한 특성(기계적 및 전기적 특성, 접합성 등) 때문에 산업계에서 가장 널리 사용되고 있다. (중략)

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.464-466
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• 2009

This study tried to examine the suitability of strip casting process such as PFC (Planar Flow Casting) method for soldering Au-Sn strip. The effect of heat treatment on the tensile behavior and mechanical properties of an Au-Sn strip was investigated through tensile test, micro hardness test, X-ray diffraction (XRD), SEM, and TEM observations. It was apparent that 20-mm width Au-Sn strip could be well produced by using planar flow casting process. Tensile results showed that tensile strength increased from 338.3MPa to 310MPa and plastic strain improved from 0% to 1.5% with heat treatment ($170^{\circ}C$/70 hrs.). The microstructure of Au-Sn strip mainly consisted of two phases; $Au_5Sn(\zeta)$ and AuSn($\sigma$). It was also found that inhomogeneous amorphous local structure continuously changed to the homogeneous two phases microstructure with heat treatment. The fractographical observation after tensile test indicated the cleavage fracture mode of as-casted Au-Sn strip. On the other hand, the heat treated Au-Sn strip showed that fracture propagated along interface between brittle AuSn and ductile $Au_5Sn$ phases. The deformation behavior of strip casted Au-Sn alloy with microstructural evolution and the improve method for ductility of this alloy was also suggested.

• 한국화재소방학회논문지
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• 제14권2호
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• pp.33-38
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• 2000

전자산업의 공정에서 PCB기판납땜은 괼수적이며 이에 사용하는 Flux내 용제인 IPA(Iso--propyl alcohol)와 메탄올은 인화성과 폭발성이 강한 물질로 화재위험성이 대단히 높다. 또한 메탄올은 유독성물질로 지정되어 있으며, 환경법상 VOC(Volatile Organic Compound : 휘발성유기화합물)규제물질로 지정되어 있어 대체물질 개발이 절실히 요구된다. 이에 기존 Flux특성을 가지고 있으면서 화재위험성은 없고, 휘발성유기화합물 규제물질에는 해당되지 않는 디클로로프로판(Dichloropropane, DCP)를 주성분으로 하여 Flux 특성에 맞는 안정제 및 첨가제를 적정 조성비로 조합하여 용제를 개발하였다. 그 결과 200ppm의 작업환경허용농도를 470 ppm으로 완화시킬 수 있었으며 납땜불량율은 0.083%에서 0%로, 퍼짐성은 85%에서 87%로, 전연저항은 1.0$\times$$10^{12}$$\Omega$에서 6.9$\times$$10^{12}$/$\Omega$으로 기존 Flux보다 우수하였다. 그러므로 Flux의 안정성은 물론 환경안전측면과 품질, 생산성도 향상이 가능함을 확인하였고, 품질 특성시험 및 제품 신뢰성 시험 결과 만족할 만한 곁과를 얻었다.

• 한국재료학회지
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• 제13권1호
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• pp.18-23
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• 2003

Properties of Ag thick films fabricated by using low temperature curable silver pastes were investigated. Ag pastes were consisted of polymer resins and silver powders. Ag pastes were used for conductive or fixing materials between board and various electrical and electronic devices. Low temperature curable Ag pastes have some advantages over high temperature curable types. In cases of chip mounting, soldering properties were required for screen printed Ag thick films. In this study, four types of Ag pastes were fabricated with different compositions. Screen printed Ag thick films on alumina substrates were fabricated at various curing temperatures and times. Thickness, resistivity, adhesive strength and solderability of fabricated Ag thick films were characterized. Finally, Ag thick films produced using Ag pastes, sample A and B, cured at $150^{\circ}C$ for longer than 6 h and $180^{\circ}C$ for longer than 2 h, and $150^{\circ}C$ for longer than 1 h and $180^{\circ}C$ for 1 h, respectively, showed low resistivities of $10^{-4}$ $∼10^{-5}$ Ωcm and good adhesive strength of 1∼5 Mpa. Soldering properties of those Ag thick films with curing temperatures at solder of 62Sn/36Pb/3Ag were also investigated.

• 마이크로전자및패키징학회지
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• 제27권3호
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• pp.35-39
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• 2020

Nonwet (Head in Pillow) 불량은 SMT(surface mount technology) 공정 불량 유형 중 하나로 이 불량은 solder paste misalign, reflow 조건, package warpage, package ball size 등과 같은 인자에 따라 불량이 발생을 한다. 이에 본 논문은 Nonwet 발생 인자 중 ① reflow 조건 ② package ball & solder paste misalign ③ package ball 크기 type에 대한 인자를 선정하여 nonwet 실험을 진행하였다. 먼저 reflow 조건의 경우 soldering 시간이 길 경우 nonwet risk가 증가를 하나, reflow 공정에 N₂를 적용할 시 solder ball 산화 억제에 따른 nonwet 개선을 확인 할 수 있었다. 또한 package ball과 solder paste misalign 발생 시 ball과 paste의 접촉 깊이가 20 ㎛ 이하의 경우 nonwet에 취약 했으며, package ball 체면적이 작을수록 nonwet 관점 개선됨을 확인 할 수 있었다.