42 Result(s)
within
English
Materials Science
Characterization and Evaluation of Materials
Young-Ho Kim
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Article
Precipitation hardening and recrystallization in Cu-4% to 7% Ni-3% Al alloys
The effects of microstructure on mechanical properties in three cold-worked Cu-4% to 7% Ni-3% Al alloys have been investigated by changing ageing time at 500 °C. Hardness and strength in the Cu-7% Ni-3% Al and...
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Article
Influence of Cu Deposition Conditions on the Microstructure and Adhesion of Cu/Cr Thin Film to Polyimide Film
The microstructure of Cu thin films in various deposition conditions and the influence of their microstructure on the adhesion strength between Cu/Cr films and polyimides were studied. Cr films (50 nm thick) a...
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Article
A study on the development of engineering plastic piston used in the shock absorber
A piston is an important component of the shock absorber which determines comfortable riding and handling. Conventional piston is made of metal powder that is pressed in a mold, and then sintered at high tempe...
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Article
Microstructural change and interfacial reactions of Pt/Ti thin films on SiNx/Si during annealing in various ambients
The microstructural changes and interfacial reactions of Pt/Ti/SiNx/Si during annealing were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Auger electron spectroscopy (AE...
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Article
Analysis of 1/f noise in LWIR HgCdTe photodiodes
We study the 1/f noise currents and dark currents in LWIR HgCdTe photodiodes. The measured dark currents of the diodes processed by post implantation annealing with different annealing times are analyzed using...
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Article
Surface leakage current analysis of ion implanted ZnS-passivated n-on-p HgCdTe diodes in weak inversion
Effects of fixed charge on R0A value of ZnS-passivated x=0.3 HgCdTe n-on-p diode are explained as a shunt resistance that affects current-voltage (I-V) and dynamic resistance-voltage (Rd-V) characteristics. The f...
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Article
Characteristics of gradually doped LWIR diodes by hydrogenation
The hydrogenation effects on HgCdTe diode performance are presented and the mechanism of hydrogenation is revealed. By the hydrogenation, R0A is increased by 30 times and photo-response is also improved. It is su...
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Article
Texture enhancement of Al films on Ti underlayers by radio-frequency bias sputtering
The influence of sputtering pressure and radio-frequency (RF) bias power on the texture of Al/Ti thin films has been investigated. The Al/Ti thin films were deposited sequentially onto thermally oxidized Si wa...
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Article
Interfacial microstructure and intermetallics developed in the interface between in solders and Au/Ni/Ti thin films during reflow process
Intermetallic phases and microstructures formed between In solder and Au/Ni/Ti thin films during reflow were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission el...
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Article
Microstructure characterization of Sn-Ag solder joints between stud bumps and metal pads
The microstructure of the flip-chip solder joints fabricated using stud bumps and Pb-free solder was characterized. The Au or Cu stud bumps formed on Al pads on Si die were aligned to corresponding metal pads ...
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Article
The microstructure characterization of ultrasmall eutectic Bi-Sn solder bumps on Au/Cu/Ti and Au/Ni/Ti under-bump metallization
The microstructure of the ultrasmall eutectic Bi-Sn solder bumps on Au/Cu/Ti and Au/Ni/Ti under-bump metallizations (UBMs) was investigated as a function of cooling rate. The ultrasmall eutectic Bi-Sn solder b...
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Article
Contact resistance and shear strength of the solder joints formed using Cu bumps capped with Sn or Ag/Sn layer
Solder joints were successfully bonded by joining Ag/Sn/Cu bumps and Ag/Sn/Cu layers at 200°C for 30 sec under 20 MPa, 40 MPa, and 80 MPa using thermo-compression bonder. The solder joints were aged at 150°C u...
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Article
A comparison of gamma radiation effects on bromine- and hydrazine-treated HgCdTe photodiodes
In this study, we investigated the effects of gamma radiation on ZnS/CdTe-passivated HgCdTe photodiodes that were fabricated with one of two different surface treatments using bromine, Br2, or hydrazine, N2H4. Un...
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Article
Bottom electrode etching effect on the electrical properties of lead strontium titanate thin film
(Pb0.4Sr0.6)TiO3 thin films were prepared by a modified sol-gel method on Pt/Ti/SiO2/Si substrates, where lower figure of merit of about 16% was observed in spite of higher tunability above 58%. The electrode sur...
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Article
Characteristics of the Interfacial Microstructure of Chip-on-Plastic Joints under Thermal Cycling and Aging Treatment
This study presents the change of contact resistance and microstructure evolution of chip-on-plastic (COP) joints during the thermal cycling (T/C) test and aging treatment. Results showed that the average cont...
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Article
Nucleation and Growth of Zinc Particles on an Aluminum Substrate in a Zincate Process
The nucleation and growth of zinc particles during a conventional zincate process were investigated. Zinc particles preferentially nucleated on the peak or edge of an aluminum surface and preferentially grew w...
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Article
Improvement of LDI BUMP Strip** Process by Development of Room Temperature PR Stripper
Bump process using gold bump led to many cleaning problems like polymer residues, metal and polyimide consumption after strip** process. First of all, strip** process of bump photoresist is one of the diff...
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Article
Dielectric properties of zinc titanate thin films prepared by Rf magnetron sputtering
Zinc titanate thin films of ~500 nm in thickness were synthesized by an RF magnetron sputtering using a sintered ceramic target. After annealing in temperature ranges of 300–800 °C, their phase transition and ...
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Article
Mechanism of the Delayed Growth of Intermetallic Compound at the Interface between Sn−4.0Ag−0.5Cu and Cu−Zn Substrate
A Cu−Zn wetting layer was very effective to depress the excessive growth of intermetallic compound (IMC). The effect of Zn addition to the Cu layer on the IMC growth and microvoid formation in the solder inter...
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Article
Kinetics of Intermetallic Compound Formation at the Interface Between Sn-3.0Ag-0.5Cu Solder and Cu-Zn Alloy Substrates
The growth kinetics of an intermetallic compound (IMC) layer formed between Sn-3.5Ag-0.5Cu (SAC) solders and Cu-Zn alloy substrates was investigated for samples aged at different temperatures. Scallop-shaped Cu6S...
