• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.551-552
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• 2008

This paper presets a results of frequency response in variation of wire bonding length. A gold ball bonding is used as a wire bonding process, and a DPDT(double pole double thru) switch is adapted as a device for test. Wire length is ranged from 442um to 833um and a measured frequency range is from 1 GHz to 6 GHz. Little difference are measured in insertion loss and return loss depending on wire length. Measured S21 and S11 are -0.58 dB and -17.7 dB, respectively. S21 insertion loss is rising up and S11 insertion loss is falling down as the frequency is increased.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.34-36
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• 2005

Copper wire bonding is an alternative interconnection technology that serves as a viable and cost saving alternative to gold wire bonding. In this paper, ultrasonic wedge bonding with $25{\mu}m$ copper wire on Au/Ni/Cu metallization of a PCB substrate was performed at ambient temperature. The central composite design of experiment (DOE) approach was applied to optimize the copper wire wedge bonding process parameters. After that, pull test of the wedge bond was performed to study the bond strength and to find the optimum bonding parameters. SEM was used to observe the cross section of the wedge bond. The pull test results show good performance of the wedge bond. Additionally, DOE results gave the optimized parameter for both the first bond and the second bond. Cross section analysis shows a continuous interconnection between the copper wire and Au/Ni/Cu metallization. The diffusion of Cu into the Au layer was also observed.

• Journal of Acupuncture Research
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• v.33 no.1
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• pp.79-93
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• 2016

Objectives : The purpose of this study is to explore research trends in gold implantation therapy performed on the animal and human body, through a review of clinical studies focused on gold thread, gold needle and gold bead. Methods : Medical databases, including Pubmed, CENTRAL, MEDLINE, EMBASE, RISS4u, KISTI, OASIS and KTKP, were searched for relevant articles published from their launch to December 31, 2015 using the key word 'gold' with '$thread^*$', '$needle^*$', '$acupuncture^*$', '$wire^*$', '$bead^*$', '$embed^*$', '$implant^*$', or '$insert^*$'. The results were classified into in vivo studies, clinical trials and clinical reports. Analysis of the results was conducted in several research areas, from the identity of studies such as nationality and published year, to the gold preparations-features and implanted locations and to the outcomes that reflect the clinically favorable or adverse effect of gold implantation therapy. Results : A total of 30 studies including 11 in vivo studies, 4 clinical trials and 15 case reports, were found in the search. We observed certain research trends according to the research time, nationality and target indication of the studies. The studies primarily revealed a chronic local inflammatory response which could be a useful mechanism for pain-relief in musculoskeletal diseases and facial rejuvenation. Researches concerning long-term reactions or adverse effects were rare. Conclusion : The results show that the efforts to discover the level of clinical efficacy of gold implantation therapy were steady and worldwide. However, further researches on the longterm effect, and more importantly, the safety of gold implantation therapy are required.

• Imaging Science in Dentistry
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• v.44 no.1
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• pp.81-84
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• 2014

This report described a case in which diagnostic radiographs showed irregular dense radiopaque strings and curved lines in the head and neck area. These artifacts could lead to misinterpretation since they may obscure anatomical structures and/or mask critical structures/pathologies. A more detailed history of the patient indicated that these strings originated from a facelift procedure in which a gold-wire technique was used. Considering that such intervention may cause a radiodiagnostic burden, it should be included in the anamnesis prior to radiography.

• Conservation Science in Museum
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• v.17
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• pp.1-16
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• 2016

The gold buckle excavated from Seogam-ri Tomb No. 9(National Treasure No. 189), one of the oldest gold artifacts discovered within the Korean Peninsula, was created using granulation techniques. The buckle is made with 22.8K gold sheets and features a decorative design with seven dragons in repousse metalwork. The outlines of the dragons and the edge of the buckle are finished with 23.8K gold wires and granules. Some curved sections of the buckle are also covered with an extra sheet of 23.8K gold, possibly added to repair defects discovered during production or thereafter. Gold wire used to render the dragon's nostrils is slightly lower in purity(23.3K) and was probably preferred in this case due to its increased hardness. As a result, the metal is better able to retain the complex shape of the dragons' nostrils, created by rolling gold wire into spirals. The buckle's gold granules are found in small, medium and large sizes and are presumed to have been bonded using copper. The foreheads and the bodies of the seven dragons are inset with turquoise and the eyes are decorated with red cinnabar/vermillion(HgS).

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.1
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• pp.52-58
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• 2007

We propose a new contact detection algorithm for fine pitch wire bonding. Fast and stable contact detection of the z-axis in wire bonding is extremely important to maintain the quality of fine pitch gold wire bonding processes, which use a small pad less than $70{\mu}m$ in diameter. A small perturbation in the contact detection time causes a large difference in the size of the formed squashed ball. The new detection method is based on a statistical approach and designed for a discrete Kalman filter. It is faster and has smaller detection time variations than conventional detection methods. Experimental results are presented to demonstrate the advantages of the proposed algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.137-145
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• 2005

A new design of contact detection algorithm is proposed for the z-axis of a wire bonder that interconnects between pads and leads in semiconductor manufacturing processes. Fast and stable contact detection of the z-axis is extremely important fer maintaining proper quality in the fine pitch gold wire bonding process, which has a small pad size of below 70um. The new method is based on a statistical approach and designed for the discrete Kalman filter. Real wire bonding experimental results are presented to demonstrate the advantages of the proposed algorithm.

• Restorative Dentistry and Endodontics
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• v.42 no.4
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• pp.301-308
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• 2017

Objectives: It was aimed to compare the cyclic fatigue resistances of ProTaper Universal (PTU), ProTaper Next (PTN), and ProTaper Gold (PTG) and the effects of sterilization by autoclave on the cyclic fatigue life of nickel-titanium (NiTi) instruments. Materials and Methods: Eighty PTU, 80 PTN, and 80 PTG were included to the present study. Files were tested in a simulated canal. Each brand of the NiTi files were divided into 4 subgroups: group 1, as received condition; group 2, pre-sterilized instruments exposed to 10 times sterilization by autoclave; group 3, instruments tested were sterilized after being exposed to 25%, 50%, and 75% of the mean cycles to failure, then cycled fatigue test was performed; group 4, instruments exposed to the same experiment with group 3 without sterilization. The number of cycles to failure (NCF) was calculated. The data was statistically analyzed by using one-way analysis of variance and post hoc Tukey tests. Results: PTG showed significantly higher NCF than PTU and PTN in group 1 (p < 0.05). Sterilization significantly increased the NCF of PTN and PTG (p < 0.05) in group 2. PTN in group 3 had significantly higher cyclic fatigue resistance than PTN group 4 (p < 0.05). Also, significantly higher NCF was observed for PTG in group 2 than in groups 3 and 4 (p < 0.05). Conclusions: PTG instrument made of new gold alloy was more resistant to fatigue failure than PTN and PTU. Autoclaving increased the cyclic fatigue resistances of PTN and PTG.

• Corrosion Science and Technology
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• v.20 no.5
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• pp.289-294
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• 2021

In this study, after measuring polarization characteristics of 97.3 wt% Ag, Au-Coated 97.3 wt% Ag (ACA) and 100 wt% Au wires in 1 wt% H₂SO₄ and 1 wt% HCl electrolytes at 25 ℃, corrosion rate and corrosion characteristics were comparatively analyzed. Comparing corrosion potential (E_CORR) values in sulfuric acid solution, ACA wire had more than six times higher E_CORR value than Au wire. Thus, it seems possible to use a broad applied voltage range of bonding wire for semiconductor packaging which ACA wire could be substituted for the Au wire. However, since the E_CORR value of ACA wire was three times lower than that of the Au wire in a hydrochloric acid solution, it was judged that the use range of the applied voltage and current of the bonding wire should be considered. In hydrochloric acid solution, 97.3 wt% Ag wire showed the highest corrosion rate, while ACA and Au showed similar corrosion rates. Additionally, in the case of sulfuric acid solution, all three types showed lower corrosion rates than those under the hydrochloric acid solution environment. The corrosion rate was higher in the order of 97.3 wt% Ag > ACA > 100 wt% Au wires.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.201-218
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• 1989

The purpose of this study was to evaluate the influence of attachment technique on mechanical properties and microstructures of wrought wires. The wires tested in this study were precious metal wires: PGP (Platinum-Gold -Palladium), Elastic #12, Denture Clasp, Standard, Jelenko No. 2, Degulor-Klammerdraht, DM (Dong Myung) and base metal wire : Ticonium. Each wire was divided into three groups, and each group was heat treated as embedding, cast to, and soldering state. Heat treated sample was evaluated by tensile test, bending test, microhardness test, element analysis and microstructure test. The obtained results were as follows: 1. In tensile test, cast to and soldering procedures have an effect on wrought wire clasp as hardening heat treatment. 2. Maximum bending strength was significantly increased in Elastic #12, Denture Clasp, Standard, and DM in cast to procedure. 3. Ticonium showed the highest Victors hardness number, followed by PGP, and there was no significant difference in other wrought wires. In cast to and soldering procedure, Victors hardness number was significantly increased in precious wrought wires. 4. The precious wrought wire showed typical fibrous structure and this was disappeared in cast to and soldering procedure. But physical properties were not influenced by this phenomenon.