• JSTS:Journal of Semiconductor Technology and Science
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• v.6 no.3
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• pp.136-145
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• 2006

Two major processing technologies of GaAs HBT and pHEMT have been released in production at Win Semiconductors corp. to address the strong demands of power amplifiers and switches for both handset and WLAN communications markets. Excellent performance with low processing cost and die shrinkage features is reported from the manufactured MMICs. With the stringent tighter manufacturing quality control WIN has successfully become one of the major pure open foundry house to serve the communication industries. The advancing of both technologies to include E/D-pHEMTs and BiHEMTs likes for multifunctional integration of PA, LNA, switch and logics is also highlighted.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.159-162
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• 2004

The processing of phenolic composite reinforced with hybrid of PAN based/Rayon based carbon fabrics using FBG sensor and thermocouple was studied. Once the composite is cured, the reflection spectrum from the FBG sensor shifted the center wavelength with an increase in the temperature. Also, the change in the form of the reflection spectrum obtained during the cooling process of the cure cycle was caused by the thermal shrinkage. During the curing process, uniform distribution of the temperature profile was observed throughout the sample.

• Journal of the Korean Home Economics Association
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• v.42 no.8
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• pp.113-121
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• 2004

This study used cupric sulfate as a bum-out agent. The concentration of cupric sulfate, temperature and time were varied with glycerin included or excluded on the properties of polyester ground fabrics. The results are as follows. The effect of carbonization with glycerin included was decreased, but removal of carbide with glycerin included was easier than that with glycerin excluded. The white index and tensile strength of polyester ground fabrics were decreased as the processing concentration, temperature and time increased. The shrinkage was increased as the processing concentration, temperature and time increased. The optimum conditions with cupric sulfate as the bum-out agent was 5％ concentration, 140$^{\circ}C$, 3min., and 3kgf/cm$^2$ and with cupric sulfate added to glycerin was 5％ concentration, 150$^{\circ}C$, 5min., and 3kgf/cm$^2$.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.48-53
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• 2004

Injection molded plastic parts have many surface defcts: Warpage, wedline, flowmark, zetting, scratching, shading and so on. In the desktop mnitor's case, Weld line have been one of the main surface defects. Nowadays in the pursuit of light weight of parts, one of the big problems of LCD Monitor thinks Warpage and surface shrinkage. In this paper, we introduce some instances for prevevting these defestcs in the side of mould drawing, parts drawing and processing condition. Based on these, we tried to find out the optimum processing conditions through repeatedly tried injection moulding after reflecting these instances.

• Design & Manufacturing
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• v.2 no.2
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• pp.33-37
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• 2008

This paper describes the optimization of injection molding conditions to minimize sink marks. Sink marks, which refer to a small depression on the surface opposite a thick wall thickness, are often encounted in injection molded plastic parts. Part geometry, material properties and processing conditions during injection molding can affect the sink mark depth. We designed the runner system which is possible balanced filling to cavities using CAE program and then obtained optimal processing conditions by Taguchi's Robust Design technique. By actual injection molding using optimized mold and molding conditions, it confirmed that sink mark depth decreased zero compared to 1mm level in the conventional mold and process.

• Laser Solutions
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• v.3 no.3
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• pp.21-29
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• 2000

For the direct metal shape processing the powder feed device which is different from the widely used in rapid prototyping. is developed, The three dimensional object is shaped with the melting metal powder. The developed research has applied to rapid prototyping in ultraprecision for MEMS and medical science fields required of rapid manufacture of complex shape. The goal of this study make 3D model which has precision accuracy. Powder spreading apparatus has been more improved because that the control of powder spread is very important in layer manufacturing. It consists of the vibration motor, nozzle and tube which supplies various metal powder. This apparatus could control the spreading velocity that could control powder spreading thickness. Laser on/off switch was adapted because laser scanning velocity must be preserved constantly to prevent heat transformation of laser overheating. The error between sintered thickness md experimental one occurred by shrinkage in sintering melting process. The problem of heat transformation was solved by On/Off switching system.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.7
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• pp.111-115
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• 2008

This paper describes the optimization of injection molding conditions to minimize sink marks. Sink marks, which refer to a small depression on the surface opposite a thick wall thickness, are often encounted in injection molded plastic parts. Part geometry, material properties and processing conditions during injection molding can affect the sink mark depth. We designed the runner system which is possible balanced filling to cavities using CAE program $Moldflow^{TM}$ and then obtained optimal processing conditions by Taguchi's Robust Design technique. By actual injection molding using optimized mold and molding conditions, it confirmed that sink mark depth decreased zero compared to 1mm level in the conventional mold and process.

• Textile Coloration and Finishing
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• v.16 no.5
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• pp.54-61
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• 2004

This research surveys the differences of fabric mechanical properties with the different looms and the fabric positions according to the warp and weft yarn tensions on the Vamatex and Omega-Panter looms respectively. For this purpose, the grey fabrics woven by PET filament using two test looms are dyed and finished. The processing shrinkages are measured on each processes such as dryer, scouring, pre-set, dyeing and final-set using the fabric density and width. The mechanical properties of the finished fabrics are measured and discussed with relation to the warp and weft yarn tensions of the two looms and the fabric positions. In addition, the fabric thickness according to the fabric positions such as right, left selvedges and center of the fabrics is also measured and discussed with the characteristics of the Vamatex and Omega-Panter looms.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.1
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• pp.33-40
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• 1997

The microbial growth of fresh, vacuum packaged, cook-in-bag uncured beef patties was determined in two film structures, a commercial (PE/EVOH), and super barrier ($SiO_2$ coated polyester) material. Packaged samples were cooked to internal temperature of 71 and $82^{\circ}C$ for 30 minutes, and stored in temperature abused ($23{\pm}2^{\circ}C$) and refrigerated storage ($4-6^{\circ}C$). Barrier properties had a significant effect (p<0.001) on aerobic and mesophilic growth in the abused condition. Cooking temperatures had a statistically significant effect (p<0.05) on aerobic growth in the refrigerated condition. The growth of anaerobes and psychrophiles were not significantly effected by either variables. Storage times had the most significant effect (p<0.001) for all groups of microorganisms. The physical properties of the commercial film (strength, thickness, and shrinkage) were changed after exposure to thermal treatment, while the super barrier package had actually no change.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.282-285
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• 2012

Lead-free (Bi0.5Na0.41K0.09)TiO3 (BNKT) multilayer ceramic actuators were prepared using tape-casting and screen-printing techniques. Co-firing behavior of BNKT/AgPd laminates was examined as a function of sintering temperature. It was found that co-firing induced bending and electrical properties were very sensitive to sintering condition. By optimizing sintering conditions, lead-free electrostrictive multilayer actuators with normalized strain Smax/Emax of 266 pm/V have been successfully fabricated, which is promising for lead-free actuator applications.