• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.15-16
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• 2008

In case manufacturing COF, through hole should be made to be used for a pathway connecting the conductive layers of its both faces. In case Cu-plating inside of through hole with electroless plating way, contact between Cu and PI film gets bad to be fell apart from PI by the impact of applying to the electric devices. Therefore, after sputtering is applying on inner through hole, then a method to perform electroplating process. In this study, after changing sputtering condition to manufacture FCCL, we looked the changeability of the upper PI and inner hole Cu layers. Making use of RF Magnetron sputtering equipment, we coated Cu thin film and Cu-plated on it through electroplating. After cold-mounting the completed FCCL, we examined hole section through an optical microscope. From the result of test, with parameters deposition pressure and deposition time, both the thickness of the hole plated layer and PI plated upper layer increased at regular rate, increasing the thickness of Cu sputter layer. However, from the result of test in increasing RF-power, we could know the increment rate of hole plated layer is considerably greater than that of PI plated upper layer. Therefore, we finally acquired good result; if you want only to increase the plated layer of inner hole, it's much better to increase RF-power.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.7
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• pp.63-71
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• 1998

Generally, electronic packaging designer uses HSPICE SOFTWARE TOOL to validate electric characteristics of traces layout before layout traces in PCB in hundreds Mb/s high speed digital circuits. We are in need of a plated through hole (PTH) model and a connector model to use HSPICE SOFTWARE TOOL. Those models have not been perfectly defined for HSPICE simulation. In this paper, we define a PTH model and a connector model for HSPICE simulation and discuss application range for these models. Th emodels are analytic models very applicable for HSPICE simulation and are used to analyze electric characteristic of the PTH and the connector in thetraces layout in high speed digital circuit.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.55-67
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• 2010

The electrical properties of a back drilled via-hole (BDH) without the open-stub and the plated through via-hole (PTH) with the open-stub, which is called the conventional structure, in a high-count multi~layered (HCML) printed circuit board (PCB) were investigated for a high-speed digital system, and a selected inner layer to transmit a high-speed signal was farthest away from the side to mount the component. Within 10 GHz of the broadband frequency, a design of experiment (DOE) methodology was carried out with three cause factors of each via-hole structure, which were the distance between the via-holes, the dimensions of drilling pad and the anti-pad in the ground plane, and then the relation between cause and result factors which were the maximum return loss, the half-power frequency, and the minimum insertion loss was analyzed. Subsequently, the empirical formulae resulting in a macro model were extracted and compared with the experiment results. Even, out of the cause range, the calculated results obtained from the macro model can be also matched with the measured results within 5 % of the error.

• Corrosion Science and Technology
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• v.8 no.4
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• pp.148-152
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• 2009

The failure of a Zn-plated carbon steel pipe that served as a fire sprinkler was investigated in terms of the pipe's corrosion products. The pipes leaked through holes formed beneath the tubercles. The formation of oxygen concentration cell involves colonization of metal surface by aerobic bacteria or other slime formers, and anodic reaction beneath tubercle is accelerated by the presence of SRB, leading to the formation of hole beneath tubercle.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.481-485
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• 2000

A new type of compliant press-fit pin has been developed and evaluated for use packaging of electronic telecommunications equipments. Main requirements for design are defined the upper limit of pin insertion force and the lower limit of pin retention force. Upper limit of pin insertion force is set to protect the copper plate of the inner PTH wall. Lower limit of pin retention force is set to satisfy a wire-wrapping specification. Results are represented by insertion force and retention force variations according to the front angle, rear angle and material, etc.

• Journal of Applied Reliability
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• v.17 no.4
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• pp.280-288
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• 2017

Purpose: PBA buried in underwater requires high reliability because of its mission critical characteristic and harsh operational environment during its life cycle. Therefore, various reliability improvement activities are necessary. The defect on PBA manufacturing process have been studied, as a result, many activities and standards have been presented. However, there are less studies regarding failure pattern on physical features based on design. In this paper, we studied a possible failure patten based on physical features that is related with manufacturing process of PBA. And reliability improvement design based on PoF (Physical of Failure) were intruduced in this paper. Methods: A reliability prediction simulation were performed on the components A and B of the H system using Sherlock Software which is a PoF commercial tool from DFR solution. Solder fatigue and PTH fatigue analysis based on thermal cycling profiles and random vibration was analyzed on three earthquake response spectrum. Result: It was validated that life time and reliability improvement design through solder fatigue and PTH fatigue analysis in case of component. For compoenet B, random vibration fatigue was additionally analyzed and validated reliability for earthquakes profile. Conclusion: In design stage prior to manufacturing, PoF can be analyzed, and it is possible to make a reliability improvement/validated design using design data. This study can be applied in every design step and contribute to make more stable development product.

• Conservation Science in Museum
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• v.21
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• pp.53-66
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• 2019

This study describes the processes undertaken for the conservation treatment of metal artifacts excavated in Hasong-ri, Yeongwol, Gangwon-do and the results of the related surface composition analysis. X-ray fluorescence analysis (XRF) was applied to analyze the surface composition of a small gilt-bronze wind chime, two clappers, and a small gourd-shaped bronze bottle. The gourd-shaped bronze bottle was investigated using radiography to examine its internal structure. The wind chime and clappers were excavated from the same location. A gilt layer was identified on the wind chime, but surface corrosion made it difficult to identify any such layers on the clappers. The element analysis revealed that the wind chime was made of bronze in a Cu-Sn-Pb ternary system and was gilt-plated using mercury amalgam. The clappers were made from copper with a small amount of gold detected, but did not show any evidence of mercury. Since a thick corrosion layer was affixed to the surface of each clapper, it was impossible to identify the surface composition and determine if the clappers had been gilded. It is possible that the gold detected from the clappers was a foreign substance or had detached from the giltbronze wind chime buried alongside them. The small gourd-shaped bronze bottle was investigated through surface element analysis and radiography to verify if it was a type of silver bottle used as currency during the Goryeo dynasty. The radiography photography identified that a small hole in the middle of the base had been stopped up. The general surface analysis did not detect silver, which suggests that the bottle was made of bronze instead and was not one of the silver bottles used as a means of currency.