• Journal of the Microelectronics and Packaging Society
• /
• v.10 no.2
• /
• pp.33-37
• /
• 2003

The new textured surface epitaxial base(TSEB) cell as a high efficiency Si solar cell was fabricated and its eletro-optical characteristics were investigated. The fabricated device showed the open circuit voltage of 0.62 V, the short circuit current of 40 mA, the fill factor of 0.7, and the efficiency of 16% under the incident light of AM-1 100 mW/$cm^2$. The TSEB cell proposed in this paper has the structural superiority in the fabrication of high efficiency solar cell due to the carrier drift transport in the optical absorption region and the formation of back surface field by $P^-/P^+$ epitaxial base, and the low emitter series resistance by insertion of $n^+$ buried contact.

• Journal of Sensor Science and Technology
• /
• v.13 no.6
• /
• pp.430-435
• /
• 2004

The resolution of the accelerometer, fabricated with MEMS technology is mainly affected by mechanical and electrical noise. To reduce mechanical noise, we have to increase mass of the structure part and quality factor related with the degree of vacuum packaging. On the other hand, to increase mass of the structure part, the thickness of the structure must be increased and ICP-RIE is used to fabricate the high aspect ratio structure. At this time, footing effect make the sensitivity of the accelerometer decreasing. This paper presents a hybrid SOG(Silicon On Glass) Process to fabricate a lateral silicon accelerometer with differential capacitance sensing scheme which has been designed and simulated. Using hybrid SOG Process, we could make it a real to increase the structural thickness and to prevent the footing effect by deposition of metal layer at the bottom of the structure. Moreover, we bonded glass wafer to structure wafer anodically, so we could realize the vacuum packaging at wafer level. Through this way, we could have an idea of controlling of quality factor.

• Journal of the Microelectronics and Packaging Society
• /
• v.29 no.2
• /
• pp.53-58
• /
• 2022

One of the most promising emerging technologies for the next generation of nonvolatile memory devices based on resistive switching (RS) is the resistive random-access memory mechanism. To date, RS effects have been found in many transition metal oxides. However, no clear evidence has been reported that ZnO-based resistive transition mechanisms could be associated with strong correlation effects. Here, we investigated N, F-co-doped ZnO (NFZO), which shows bipolar RS. Conducting micro spectroscopic studies on exposed surfaces helps tracking the behavioral change in systematic electronic structural changes during low and high resistance condition of the material. The significant difference in electronic conductivity was observed to attribute to the field-induced oxygen vacancy that causes the metal-insulator Mott transition on the surface. In this study, we showed the strong correlation effects that can be explored and incorporated in the field of multifunctional oxide electrons devices.

• Composites Research
• /
• v.13 no.6
• /
• pp.23-29
• /
• 2000

The internal residual stresses within the multilayered structure with sharp interface induced by the difference in thermal expansion coefficient between the materials of adjacent layers often provide the source of failure such as delamination of interfaces etc. Recent development of the multilayered structure with functionally graded interface would be the solution to prevent this kind of failure. However a systematic thermo-mechanical analysis is needed for the customized structural design of multilayered structure. In this study, theoretical model for the thermo-mechanical analysis is developed for multilayered structures of the $Al-SiC_p$ functionally graded composite for electronic packaging. The evolution of curvature and internal stresses in response to temperature variations is presented for the different combinations of geometry. The resultant analytical solutions are used for the optimal design of the multilayered structures with functionally graded interface as well as with sharp interface.

• Electronics and Telecommunications Trends
• /
• v.38 no.6
• /
• pp.41-51
• /
• 2023

Heat dissipation technology for semiconductors and electronic packaging has a substantial impact on performance and lifespan, but efficient heat dissipation is currently facing limited improvement. Owing to the high integration density in electronic packaging, heat dissipation components must become thinner and increase their performance. Therefore, heat dissipation materials are being devised considering conductive heat transfer, carbon-based directional thermal conductivity improvements, functional heat dissipation composite materials with added fillers, and liquid-metal thermal interface materials. Additionally, in heat dissipation structure design, 3D printing-based complex heat dissipation fins, packages that expand the heat dissipation area, chip embedded structures that minimize contact thermal resistance, differential scanning calorimetry structures, and through-silicon-via technologies and their replacement technologies are being actively developed. Regarding dry cooling using single-phase and phase-change heat transfer, technologies for improving the vapor chamber performance and structural diversification are being investigated along with the miniaturization of heat pipes and high-performance capillary wicks. Meanwhile, in wet cooling with high heat flux, technologies for designing and manufacturing miniaturized flow paths, heat dissipating materials within flow paths, increasing heat dissipation area, and reducing pressure drops are being developed. We also analyze the development of direct cooling and immersion cooling technologies, which are gradually expanding to achieve near-junction cooling.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.4
• /
• pp.281-287
• /
• 2016

Fiber Bragg grating (FBG) sensors are applied in structural health monitoring (SHM) in various application fields because of their ease of multiplexing and capability of performing absolute measurements. Moreover, the packaging methods of FBG sensors accelerate their commercialization rapidly. However, long-term SHM exposes the FBG sensors to cyclic thermal loads, and a investigation is required because it finally leads to the signal instability of the FBG sensors. In this study, the effects of sensor packaging methods two methods are generally used for the FBGs: (bonding both sides of the FBG or bonding the FBG directly on signal stability of FBG sensors are investigated. Tests are conducted on specimens in a thermal chamber, over a temperature range from $-20^{\circ}C$ to $60^{\circ}C$ for 300 cycles. Signal characteristics such as Bragg wavelength, light intensity and full width at half maximum are examined and are compared with those of the FBG sensors, obtained in a previous study under direct bonding conditions. From the comparison, it is observed that the FBG sensors with bonding on both sides of the FBG demonstrate higher signal stabilities when exposed to cyclic thermal loads during long-term SHM. Consequently, it guarantees more effectiveness when packaging the FBG sensors.

• Journal of the Microelectronics and Packaging Society
• /
• v.29 no.3
• /
• pp.25-29
• /
• 2022

Recently, the importance of electronic packaging technology has been attracting attention, and heterogeneous integration technology in which chips are stacked out-of-plane direction is being applied to the electronic packaging field. The 2.5D integration circuit is a technology for stacking chips using an interposer including TSV, and is widely used already. Therefore, it is necessary to make the interposer mechanically reliable in the packaging process that undergoes various thermal processes and mechanical loadings. Considering the structural characteristics of the interposer on which several thin films are deposited, thermal stress due to the difference in thermal expansion coefficients of materials can have a great effect on reliability. In this study, the mechanical reliability of the metal pad for wire bonding on the silicon interposer against thermal stress was evaluated. After heating the interposer to the solder reflow temperature, the delamination of the metal pad that occurred during cooling was observed and the mechanism was investigated. In addition, it was confirmed that the high cooling rate and the defect caused by handling promote delamination of the metal pads.

• Journal of the Microelectronics and Packaging Society
• /
• v.24 no.3
• /
• pp.13-18
• /
• 2017

Water glass is much cheaper than silicon alkoxide, so it has advantage for commercialization. A condensation by acid catalyst makes considerable effect about the properties of water glass based silica aerogel among many factors in silica aerogel process. The pore structural properties of water glass based silica aerogel such as specific surface area and pore size distribution have been investigated through the changes in the amount and the kinds of acid catalyst. It has been confirmed that water glass based silica aerogel is affected by various conditions of catalyst in the condensation reaction such as the kind, concentration, and the amount of mole of acid catalyst on the properties of final products. Especially, it is checked that the effect of mole of acid is more prominent than that of concentration. In the case for conventional method with introducing 4M HCl in condensation step, the silica aerogel could be synthesized which has $394m^2/g$ of specific surface area, 2.20 cc/g of pore volume, 22.3 nm of average pore size, and 92.53% of porosity. On the other hand, when 4M sulfuric acid was used with 73 mmol at the condensation step of water glass based silica aerogel, the pore structural characteristics of water based silica aerogel showed better properties than the case of using HCl, for example, specific surface area was measured as $516m^2/g$, and pore volume, average pore diameter, and porosity were obtained as 3.10 cc/g, 24.1 nm, and 96.1%, respectively.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.6
• /
• pp.1685-1692
• /
• 2015

This study examines the mackerel distribution systems in Norway which has a leading mackerel industry, and has the purpose of analyzing the effects of structural improvements for the development of Korea's mackerel industry. The landing and distribution status of Korea and Norway's mackerel industry was compared, and the effects of structural improvements was analyzed under the assumption that a number of factors would be improved after an analysis of competitiveness. Special features of the landing and distribution systems of mackerel in Norway are Reduction of transportation costs and transportation time through E-auctions, fish Pumps, freshness management using state-of-the-art equipment and technology such as sea water cooling systems, direct landing at processing factories and Automation through fully automated sorting & packaging systems. The distribution competitiveness of Korea and Norway's mackerel industry was compared through the qualitative review of landing time and the length of distribution channel, distribution costs due to differences in trading method, quality and hygiene management and merchandising. For Korea's mackerel industry to have international competitiveness, they must have efficiency throughout the phases of landing, processing and distribution systems as observed in case of Norway.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.1055-1062
• /
• 2021

This study aims to determine the effect of consumer preferences and awareness on interest in organic vegetables. Factors observed in this study were information, consumer preferences, consumer awareness, and consumer buying interest toward organic vegetables. This research uses descriptive quantitative method. The data sampling technique uses accidental sampling method. The data was collected from respondents consisted of 100 consumers of five major retailers in the city of Bogor in Indonesia. The respondents consist of 80 female (80%), and 57 respondents are 25-34 years old (57%). In terms of education, type of job and monthly income of respondent, the sample can be categorized as middle-class segment. The data obtained were analyzed using Structural Equation Modeling with Partial Least Square (SEM-PLS). The results of this study indicate that the information obtained by consumers significantly and positively affects consumer preferences and consumer awareness of organic vegetables. Then, consumer preferences and consumer awareness significantly and positively affect the interest of consumers to buy organic vegetables. Consumer preference for organic vegetables is still considered quite low. The factors that influence the low consumer preference are the price of organic vegetables, which is more expensive than non-organic vegetables and the unattractive packaging of organic vegetables.