Yong-Ho Ko

Dr. Yong-Ho Ko

Korea Institute of Industrial Technology(KITECH)
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 June 2018 in Journal of Materials Chemistry C
Verified
Journal Article
Closed access
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MYMing Yang
Ming Yang
SKSang-Woo Kim
Sang-Woo Kim
Shuye ZhangShuye Zhang
Shuye Zhang
DPDae Young Park
Dae Young Park
Changwoo LeeChangwoo Lee
Changwoo Lee
MLMingyu Li
Mingyu Li
3-D mask with a vacuum filtration system allows efficient fabrication of complex Ag nanowire patterns with clear edges.

11 January 2021 in Materials
Verified
Journal Article
Open access
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GJGyuwon Jeong
Gyuwon Jeong
DYDong-Yurl Yu
Dong-Yurl Yu
SBSeongju Baek
Seongju Baek
JBJunghwan Bang
Junghwan Bang
TLTae-Ik Lee
Tae-Ik Lee
YKYong-Ho Ko
Yong-Ho Ko
The effects of Ag nanoparticle (Ag NP) addition on interfacial reaction and mechanical properties of Sn–58Bi solder joints using ultra-fast laser soldering were investigated. Laser-assisted low-temperature bonding was used to solder Sn–58Bi based pastes, with different Ag NP contents, onto organic surface preservative-finished Cu pads of printed circuit boards. The solder joints after laser bonding were examined to determine the effects of Ag NPs on interfacial reactions and intermetallic compounds (IMCs) and high-temperature storage tests performed to investigate its effects on the long-term reliabilities of solder joints. Their mechanical properties were also assessed using shear tests. Although the bonding time of the laser process was shorter than that of a conventional reflow process, Cu–Sn IMCs, such as Cu6Sn5 and Cu3Sn, were well formed at the interface of the solder joint. The addition of Ag NPs also improved the mechanical properties of the solder joints by reducing brittle fracture and suppressing IMC growth. However, excessive addition of Ag NPs degraded the mechanical properties due to coarsened Ag3Sn IMCs. Thus, this research predicts that the laser bonding process can be applied to low-temperature bonding to reduce thermal damage and improve the mechanical properties of Sn–58Bi solders, whose microstructure and related mechanical properties can be improved by adding optimal amounts of Ag NPs.

24 June 2019 in Catalysts
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Journal Article
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KPKyoung Ryeol Park
Kyoung Ryeol Park
JJJae Eun Jeon
Jae Eun Jeon
GAGHULAM ALI
GHULAM ALI
YKYong-Ho Ko
Yong-Ho Ko
JLJaewoong Lee
Jaewoong Lee
SMSungwook Mhin
Sungwook Mhin
High-performance oxygen evolution reaction (OER) electrocatalysts are needed to produce hydrogen for energy generation through a carbon-free route. In this work, the solution combustion synthesis (SCS) method was employed to synthesize mixed phases of Co- and Mn-based oxides, and the relationships between the crystalline structure and the catalytic properties in the mixed phases were established. The mixed phases of Co- and Mn-based oxides shows promising OER properties, such as acceptable overpotential (450 mV for 10 mA∙cm−2) and Tafel slope (35.8 mV∙dec−1), highlighting the use of the mixed phases of Co- and Mn-based oxides as a new efficient catalysts for water splitting. Electronic structure of the mixed phases of Co- and Mn based oxides is studied in detail to give insight for the origin of high catalytic activities. In addition, excellent long-term stability for OER in alkaline media is achieved for the mixed phase of Co- and Mn based oxides.

27 July 2018 in Metals
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Journal Article
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JBJunghwan Bang
Junghwan Bang
DYDong-Yurl Yu
Dong-Yurl Yu
MYMing Yang
Ming Yang
YKYong-Ho Ko
Yong-Ho Ko
JYJeong-Won Yoon
Jeong-Won Yoon
CLChang-Woo Lee
Chang-Woo Lee
The exemption of Pb-bearing automobile electronics in the End of Life Vehicle (ELV) directive has recently expired, bring an urgent need to find Pb-free alloys that can maintain good performance under high-temperature and vibration conditions for automobile application. In this study, a new lead-free solder, Sn-0.7Cu-0.2Cr (wt.%) alloy, was developed. To evaluate the thermomechanical reliability of the new solder alloy in automobile electronics, a thermal shock test was performed. The results show that the presence of Cr in solder inhibits the growth of interfacial Cu3Sn layer and the formation of Kirkendall voids, which effectively improves the joint reliability under intense thermal shock condition compared with the commercial SAC305 and SC07 solders. Specifically, the shear strength of the Sn-0.7Cu-0.2Cr/Cu solder joints was higher by 23% and 44% than that of SAC305 and SC07 solder joints after 2000 cycles of thermal shock at 1 m/s shear speed.

22 October 2021 in Journal of Materials Science: Materials in Electronics
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Journal Article
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DPDae-Young Park
Dae-Young Park
JKJungsoo Kim
Jungsoo Kim
DYDong-Yurl Yu
Dong-Yurl Yu
SYSehoon Yoo
Sehoon Yoo
HPHyun-Soon Park
Hyun-Soon Park
YKYong-Ho Ko
Yong-Ho Ko

10 May 2024 in Journal of Materials Research and Technology
Verified
Journal Article
Open access
SKSeoah Kim
Seoah Kim
YKYehRi Kim
YehRi Kim
EJEunjin Jo
Eunjin Jo
HLHyeon-Sung Lee
Hyeon-Sung Lee
SMSungwook Mhin
Sungwook Mhin
DKDongjin Kim
Dongjin Kim