• Korean Journal of Materials Research
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• v.14 no.6
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• pp.443-450
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• 2004

Parylene polymer thin film shows excellent homogeneous coverage chracteristics when it was deposited onto very complex three dimensional solid matters, such as deep hole and micro crack. The parylene deposition process can be conducted at room temperature although most of chemical vapor deposition processes request relatively high processing temperature. Therefore, the parylene coating process does not induce any thermal problems. Parylene thin film is transparent and has extremly high chemical stability. For example, it shows high chemical stability with high reactive chemical solutions such as strong acid, strong alkali and acetone. The bio-stability of this material gives good chances to use for a packaging of biomedical devices and electronic devices such as display. In this review article, principle of deposition process, properties and application fields of parylene polymer thin film are introduced.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.3
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• pp.21-30
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• 2018

Driven by the recent energy saving trend, conventional silicon based power conversion modules are being replaced by modules using silicon carbide. Previous papers have focused mainly on the electrical advantages of silicon carbide semiconductors that can be used to design switching devices with much lower losses than conventional silicon based devices. However, no systematic study of their thermomechanical reliability in power conversion modules using finite element method (FEM) simulation has been presented. In this paper, silicon and silicon carbide based power devices with three-phase switching were designed and compared from the viewpoint of thermomechanical reliability. The switching loss of power conversion module was measured by the switching loss evaluation system and measured switching loss data was used for the thermal FEM simulation. Temperature and stress/strain distributions were analyzed. Finally, a thermal fatigue simulation was conducted to analyze the creep phenomenon of the joining materials. It was shown that at the working frequency of 20 kHz, the maximum temperature and stress of the power conversion module with SiC chips were reduced by 56% and 47%, respectively, compared with Si chips. In addition, the creep equivalent strain of joining material in SiC chip was reduced by 53% after thermal cycle, compared with the joining material in Si chip.

• Journal of the Korean institute of surface engineering
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• v.36 no.1
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• pp.74-78
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• 2003

The corrosion failure of electronic devices has been a major reliability concern lately. This failure is an ongoing concern because of miniaturization of integrated circuits (IC) and the increased use of polymers in electronic packaging. Recently, plasma-polymerized cyclohexane films were considered as a possible candidate for a interlayer dielectric for multilever metallization of ultra large scale integrated (ULSI) semiconductor devices. In this paper the protective ability of above films as a function of deposition temperature and RF power in an 3.5 wt.% NaCl solution were examined by polarization measurement. The film was characterized by FTIR spectroscopy and contact angle measurement. The protective efficiency of the film increased with increasing deposition temperature and RF power, which induced the higher degree of cross-linking and hydrophobicity of the films.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.11-18
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• 2022

Recently, as flexible electronic device-related technologies have received worldwide attention, the development of wiring and bonding technologies using liquid metals is required in order to improve problems such as formability in the manufacturing process of flexible devices and performance and durability in the bending state. In response to these needs, various studies are being conducted to use gallium and gallium-based alloys (eutectic Ga-In and eutectic Ga-In-Sn, etc.) liquid metals, with low viscosity and excellent electrical conductivity without toxicity, as low-temperature bonding materials. In this paper, the latest research trends of low-temperature bonding technology using gallium and gallium-based alloys are summarized and introduced. These technologies are expected to become important base technologies for practical use in the fields of manufacturing flexible electronic devices and low-temperature bonding in microelectronic packages in the future.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.4
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• pp.1-9
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• 2011

Understanding the void characterization in the solder joints has become more important because of the application of lead free solder materials and its reliability in electronic packaging technology. According to the JEDEC 217 standard, it describes void types formed in the solder joints, and divides into some categories depending on the void position and formation cause. Based on the previous papers and the standards related to the void, reliability of the BGA solder joints is determined by the size of void, as well as the location of void inside the BGA solder ball. Prior to reflow soldering process, OSP(organic surface preservative) finished Cu electrode was exposed under $85^{\circ}C$/60%RH(relative humidity) for 168 h. Voids induced by the exposure of $85^{\circ}C$/60%RH became larger and bigger with increasing aging times. The void position has more influence on mechanical strength property than the amount of void growth does.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.39-47
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• 2002

Heat is always the root of stress acting upon the electronic package, regardless of the heat due to the device itself during operation or working under the adverse environment. Due to the significant mismatch in coefficient of thermal expansion (CTE) and the thermal conductivity (K) of the packaging components, on one hand intensive research has been conducted in order to enhance the device reliability by minimizing the mechanical stressing and deformation within the package. On the other hand the effectiveness of different thermal enhancements are pursued to dissipate the heat to avoid the overheating of the device. However, the interactions between the thermal-mechanical loading has not yet been address fully. in articular when the temperature gradient is considered within the package. To address the interactions between the thermal loading upon the mechanical stressing condition. coupled-field analysis is performed to account the interaction between the thermal and mechanical stress distribution. Furthermore, process induced defects are also incorporated into the analysis to determine the effects on thermal conducting path as well as the mechanical stress distribution. It is concluded that it feasible to consider the thermal gradient within the package accompanied with the mechanical analysis, and the subsequent effects of the inherent defects on the overall structural integrity of the package are discussed.

• Journal of the Microelectronics and Packaging Society
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• v.9 no.4
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• pp.61-68
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• 2002

Thermal shock testing was used to evaluate reliability that appeared in the solder joints of electronic devices when they were subjected to thermal cycling. Recently, mobile devices have come smaller and multi-functional, with the increasing need for high-density packaging, BGA or CSP has become the main trend for surface mounting technology, and therefore mechanical stress life for solder joints in BGA/CSP type packages has required. Reliability of BGA/CSP solder joints was evaluated with electric resistivity change of daisy chain pattern and stress-strain curve measured using strain gage attached on the surface of PCB under mechanical impact loading. In this report, applications of PCB Universal Testing Machine we have developed and experimental datum of SONY estimating dynamic behavior of mechanical stress in BGA/CSP solder joints are introduced.

• Journal of Welding and Joining
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• v.25 no.2
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• pp.6-15
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• 2007

• The Optical Journal
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• s.136
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• pp.53-55
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• 2011

국내 최대 규모의 전자제조장비 종합 전시회 (Electronics Manufacturing Korea)가 2012년 4월 11일부터 13일까지 코엑스 전시장에서 개최된다. 이 전시회는 국내 주요 전자산업 핵심 분야별 비즈니스 활성화를 위해 광전자 전시회인 'Photonics Seoul'과 함께 'SMT/PCB & NEPCON KOREA', 'Printed Electronic & Electronics Materials Show', 'LED Packaging EXPO', 'Film Technology Show' 등 5개 전시회가 동시 개최되어 전시기간 동안 한자리에서 국내 최대 전자제조 장비의 최신 기술 및 제품 동향은 물론， 다양한 국내외 바이어를 만날 수 있는 기회가 될 것으로 기대된다.

• Transactions of Materials Processing
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• v.11 no.7
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• pp.614-619
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• 2002

For an accurate measurement of the material behavior of small structures, a new optical experimental technique is proposed to measure the deformation. The test method uses the dual microscope that can measure the relative deformation of two adjacent regions. The magnified view is captured by CCD cameras and the relative deformation can be measured by the pattern matching and tracing method. Using this experimental technique, the deformation of solder joints in electronic packaging and the strain of the nickel thin film are measured.