• Clean Technology
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• v.14 no.4
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• pp.265-270
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• 2008

In this study, the flow and heat transfer of the aligned pin-fin array of the air cooling module for electronic packaging application were numerically analyzed with various fin shapes. The geometric cross-sectional shapes of pin-fins considered in this study were ellipse, wing and circle. The fins had same cross-sectional area and height, but they had different surface areas. As the results, the surface area, the heat transfer coefficient, and the heat transfer performance of pin-fins greatly depended on their shapes. Of the three types of pin-fins, the wing type pin-fin with suitable shape produced the best heat transfer performance. This result implies that the cooling capacity of the pin-fin cooler can be significantly enhanced only by the change of fin shape without increasing air flow-rate or fin density.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.211-217
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• 1998

Si and ITO-coated #7059 glass wafers were electrostatically bonded by employing #7740 interlayer. It was inferred that the thermionic- electrostatic migration of $Na^{+}$ ions in the #7740 interlayer played an important role in the bonding process through SIMS analysis. The temperature and voltage required for reliable electrostatic bonding were in the range of $180{\sim}200^{\circ}C$ and $50{\sim}70V_{dc}$(10min), respectively. The low temperature Si-ITO coated glass bonding can be effectively applied to the packaging of field emission devices.

• Journal of Fisheries and Marine Sciences Education
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• v.16 no.2
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• pp.210-217
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• 2004

Cooling technology has been a vital prerequisite for the rapid, if not explosive, growth of the electronic equipment industry. This has been especially true during the last 20 years with the advent of intergrated circuit chips and their applications in computers and related electronic products. The purpose of this study is to develop a telecommunication equipment cooling system using a thermoelectric module combined with cooling fan. Thermoelectric module is a device that can perform cooling only by input of electric power. In the present study, the cooling package using the thermoeletric module has been developed to improve the thermal performance. The cooling characteristics of the electronic chip was placed into the subrack and it can be rapidly assembled or disassembled in the equipment rack. As a preliminary experiment, the cooling performances between a conventional way using a cooling fin and a proposed method applying the thermoelectric module was comosed and analyzyed. The cooling performance at a simulated electronic component packaging a thermomodule operated well.

• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.30-34
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• 2009

A Sand blasting technology has been used to address via and trench processing of glass wafer of optic semiconductor packaging. Manufactured sand blast that is controlled by blast nozzle and servomotor so that 8" wafer processing may be available. 10mm sq test device manufactured by Dry Film Resist (DFR) pattern process on 8" glass wafer of $500{\mu}m's$ thickness. Based on particle pressure and the wafer transfer speed, etch rate, mask erosion, and vertical trench slope have been analyzed. Perfect 500 um tooling has been performed at 0.3 MPa pressure and 100 rpm wafer speed. It is particle pressure that influence in processing depth and the transfer speed did not influence.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1499-1505
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• 2003

Rapid development of electronic technology requires small size, high density packaging and high power of electronic devices. So, in this paper, characteristics on oscillating heat pipe according to operating conditions(environment temperature, charging ratio of working fluid, inclination) based on experimental study was investigated. From the experimental results, $25^{\circ}C$environment temperature), R-141b(working fluid)40%(charging ratio) was best performace at others of inclination angle and The top heating mode of OCHP performed 80% efficiency of the bottom heating mode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.442-446
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• 1999

Melting behavior and bridge phenomenon of solder paste, which is essential for surface mount technology in packaging, were investigated. solder paste of Sn-37%Pb was printed on Sn-coated Cu-pattern of PCB, and heated over melting point. Melting behavior of the paste was observed using CCD-camera. In order to modelize the melting and agglomeration phenomena of the paste, two solder balls of 0.76mm diameter were used. As experimental results, the paste start to melt from the margin of the printed shape. The hight of the melted paste decreased from 270 $\mu$m to 200 $\mu$m firstly, and finally recovered to 250 $\mu$m. During the melting procedure, pores were evolved from the molten paste. Bridge Phenomenon of the molten Paste depends upon the pitch of the pattern.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.319-319
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• 2013

Even though the fabrication methods of metal oxide based thin film capacitor have been well established such as RF sputtering, Sol-gel, metal organic chemical vapor deposition (MOCVD), ion beam assisted deposition (IBAD) and pulsed laser deposition (PLD), an applicable capacitor of printed circuit board (PCB) has not realized yet by these methods. Barium Strontium Titanate (BST) and other high-k ceramic oxides are important materials used in integrated passive devices, multi-chip modules (MCM), high-density interconnect, and chip-scale packaging. Thin film multi-layer technology is strongly demanded for having high capacitance (120 nF/$mm^2$). In this study, we suggest novel multi-layer thin film capacitor design and fabrication technology utilized by plasma assisted deposition and photolithography processes. Ba0.6Sr0.4TiO3 (BST) was used for the dielectric material since it has high dielectric constant and low dielectric loss. 5-layered BST and Pt thin films with multi-layer sandwich structures were formed on Pt/Ti/$SiO_2$/Si substrate by RF-magnetron sputtering and DC-sputtering. Pt electrodes and BST layers were patterned to reveal internal electrodes by photolithography. SiO2 passivation layer was deposited by plasma-enhanced chemical vapor deposition (PE-CVD). The passivation layer plays an important role to prevent short connection between the electrodes. It was patterned to create holes for the connection between internal electrodes and external electrodes by reactive-ion etching (RIE). External contact pads were formed by Pt electrodes. The microstructure and dielectric characteristics of the capacitors were investigated by scanning electron microscopy (SEM) and impedance analyzer, respectively. In conclusion, the 0402 sized thin film multi-layer capacitors have been demonstrated, which have capacitance of 10 nF. They are expected to be used for decoupling purpose and have been fabricated with high yield.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.2
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• pp.89-95
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• 2017

Although the global coffee market is growing every year and the demand for coffee wrapping paper is increasing accordingly, research on the effect of PE material and PP material on the coffee aroma used in the sealant layer, which will directly contact the product, is lacking. In this study, we studied the change of aroma patterns and flavor materials by adding coffee to PP and PE pouches. In addition, we observed changes in aroma patterns depending on the temperature and the presence of the deoxidizer. As a result, it was found that the PP type packaging material was slightly better than the PE type packaging material, but the performance was hardly changed by the material. Rather, the change in the aroma pattern due to temperature was dominant rather than the material. It is ideal that refrigerated distribution ($4^{\circ}C$) is the best storage temperature and sales are done within a short period of time. Among the indicators, pyridine was the most suitable material to study and there are many data about pyridine. Therefore, it is expected that the results can be derived by using pyridine.

• Journal of electromagnetic engineering and science
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• v.14 no.3
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• pp.284-292
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• 2014

This paper presents a characteristic evaluation of commercial gallium nitride (GaN) transistors having two different gate-lengths of $0.4-{\mu}m$ and $0.25-{\mu}m$ in the design of a class-S power amplifier (PA). Class-S PA is operated by a random pulse-width input signal from band-pass delta-sigma modulation and has to deal with harmonics that consider quantization noise. Although a transistor having a short gate-length has an advantage of efficient operation at higher frequency for harmonics of the pulse signal, several problems can arise, such as the cost and export license of a $0.25-{\mu}m$ transistor. The possibility of using a $0.4-{\mu}m$ transistor on a class-S PA at 955 MHz is evaluated by comparing the frequency characteristics of GaN transistors having two different gate-lengths and extracting the intrinsic parameters as a shape of the simplified switch-based model. In addition, the effectiveness of the switch model is evaluated by currentmode class-D (CMCD) simulation. Finally, device characteristics are compared in terms of current-mode class-S PA. The analyses of the CMCD PA reveal that although the efficiency of $0.4-{\mu}m$ transistor decreases more as the operating frequency increases from 955 MHz to 3,500 MHz due to the efficiency limitation at the higher frequency region, it shows similar power and efficiency of 41.6 dBm and 49%, respectively, at 955 MHz when compared to the $0.25-{\mu}m$ transistor.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.4 s.37
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• pp.315-321
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• 2005

Chip-on-glass technology to attach IC chip directly on the glass substrate of flat panel display was studied by using induction heating body in AC magnetic field. With applying magnetic field of 230 Oe at 14 kHz, the temperature of an induction heating body made with Cu electrodeposited film of 5 mm${\times}$5 mm size and $600{\mu}m$ thickness reached to $250^{\circ}C$ within 60 seconds. However, the temperature of the glass substrate was maintained below $100^{\circ}C$ at a distance larger than 2 mm from the Cu induction heating body. COG bonding was successfully accomplished with reflow of Sn-3.5Ag solder bumps by applying magnetic field of 230 Oe at 14 kHz for 120 seconds to a Cu induction heating body of 5mm${\times}$5mm size and $600{\mu}m$ thickness.