• The monthly packaging world
• /
• s.205
• /
• pp.76-80
• /
• 2010

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1673-1678
• /
• 2007

The use of flip-chip type electronic package offers numerous advantages such as reduced thickness, improved environmental compatibility, and downed cost. Despite numerous benefits, flip-chip type packages bare several reliability problems. The most critical issue among them is their electrical performance deterioration upon consecutive thermal cycles attributed to gradual delamination growth through chip and adhesive film interface induced by CTE mismatch driven shear and peel stresses. The electronic package in use is heated continuously by itself. When the crack at a weak site of the electronic package occurs, thermal deformationon the chip side is changed. Therefore, we can measure these micro deformations by using Moire interferometry and find out the crack length.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.26 no.2
• /
• pp.71-76
• /
• 2020

CO₂ concentration in kimchi package has emerged recently as a potential index of product ripening to be monitored or sensed in intelligent packaging. Considering that addition of CO₂ absorber into the flexible kimchi package changes behavior of its CO₂ concentration, ripening of kimchi in total acidity, package CO₂ concentration in partial pressure (P_CO2) and package volume at 10℃ were estimated by mathematical model for two size packages included with different CO₂ absorbers. In small size package containing 0.5 kg of kimchi, relatively less gas permeable low density polyethylene (LDPE) sachet of the absorber was found to give rise of P_CO2 linearly correlated with acidity at acceptable conditions of absorber amount and size. The levels of P_CO2 at optimum ripening were different with absorber amount. However, highly gas permeable microporous spunbonded film (Tyvek) sachet did not show the linear relationship except a condition of 1.5 g of CO₂ absorbent. In large size package containing 2.0 kg, absorber sachets of LDPE and Tyvek could give the linear relationship between product acidity and package P_CO2 but at different levels (P_CO2 of package with LDPE sachet: 0.46~0.79 bar, P_CO2 of package with Tyvek sachet: 0.00~0.75 bar). The P_CO2 at optimal ripening was found to be less variable with LDPE sachets than with Tyvek ones. Use of package CO₂ concentration as an indicator of kimchi ripening was shown to be possible on the limited conditions where the linear relationship between them is established or confirmed.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.28 no.1
• /
• pp.9-14
• /
• 2022

Packages of different atmospheres (air (control), 100% CO₂, vacuum, and vacuum + O₂ absorber) were prepared for 0.4 kg rice cake (ddukgukdduk) using gas-barrier plastic film and stored at 10℃ for 11 days. The stored products were evaluated in their packages atmosphere, total aerobic bacteria, yeast and molds, texture and sensory quality during storage period. In the air package, the O₂ concentration decreased from initial 21% to 16% on storage 4 days and the CO₂ concentration increased to 23% on storage of 11 days, which resulted from the growth of microorganisms. CO₂ concentration decreased from initial 98% to 36% on storage 11 days in the 100% CO₂ package. It is reasoned that CO₂ was dissolved into the product reducing the volume of the package. Vacuum and vacuum +O₂ absorber package maintained shrunk vacuum condition until 11 days of storage. Total aerobic bacteria count increased significantly in the control package (6.41 log (cfu/g) after 11 days) compared to the 100% CO₂ package (4.96 log (cfu/g) after 11 days). Yeast and molds were 6.66 in control package, 3.43 in 100% CO₂ package, 4.66 in vacuum package, and 3.78 in vacuum + O₂ absorber package after 11 days. There was no significant difference between control and the other treatments for the texture of the stored products. Sensory quality was the worst in control package on the storage of 8 days. All treatment groups except control improved the quality preservation, but vacuum and vacuum + O₂ absorber packages suffered from cracking of the product. Thus 100% CO₂ flushing is suggested as a desired packaging condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07a
• /
• pp.32-35
• /
• 2002

The work focuses on the development of a Cu lead-frame with a single-sided adhesive tape for cost reduction and reliability improvement of LOC (lead on chip) package products, which are widely used for the plastic-encapsulation of memory chips. Most of memory chips are assembled by the LOC packaging process where the top surface of the chip is directly attached to the area of the lead-frame with a double-sided adhesive tape. However, since the lower adhesive layer of the double-sided adhesive tape reveals the disparity in the coefficient of thermal expansion from the silicon chip by more than 20 times, it often causes thermal displacement-induced damage of the IC pattern on the active chip surface during the reliability test. So, in order to solve these problems, in the resent work, the double-sided adhesive tape is replaced by a single-sided adhesive tape. The single-sided adhesive tape does net include the lower adhesive layer but instead, uses adhesive materials, which are filled in clear holes of the base film, just for the attachment of the lead-frame to the top surface of the memory chip. Since thermal expansion of the adhesive materials can be accommodated by the base film, memory product packaged using the lead-flame with the single-sided adhesive tape is shown to have much improved reliability. Author allied this invention to the Korea Patent Office for a patent (4-2000-00097-9).

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.12
• /
• pp.2217-2220
• /
• 2007

In this paper, we propose a new wafer level package (WLP) for the RF MEMS applications. The Film Bulk Acoustic Resonator (FBAR) are fabricated and hermetically packaged in a new wafer level packaging process. With the use of Au-Sn eutectic bonding method, we bonded glass cap and FBAR device wafer which has groove-shaped via formed in the backside. The device wafer includes a electrical bonding pad and groove-shaped via for connecting to the external bonding pad on the device wafer backside and a peripheral pad placed around the perimeter of the device for bonding the glass wafer and device wafer. The glass cap prevents the device from being exposed and ensures excellent mechanical and environmental protection. The frequency characteristics show that the change of bandwidth and frequency shift before and after bonding is less than 0.5 MHz. Two packaged devices, Tx and Rx filters, are attached to a printed circuit board, wire bonded, and encapsulated in plastic to form the duplexer. We have designed and built a low-cost, high performance, duplexer based on the FBARs and presented the results of performance and reliability test.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.12
• /
• pp.149-158
• /
• 1995

This paper describes the development of a software tool LCD FRAME that may guide the analyzing process for the electrical characteristics and the design procedure for constructing the thin film transistor liquid crystal display(TFT/LCD) packages. LCD FRAME can analyze its electrical characteristics from the TFT/LCD system package configuration, and provide the design variables to meet the user's requirements. These analysis and design procedure can be done in real time according to the model at simplified package level of TFT/LCD. LCD_FRAME is an object-oriented expert system which considers package elements as objects. With this LCD_FRAME software tool, we analyzed the I-V characteristics of a-Si TFT and its signal distortion which has maximum 1.58 $\mu$s delay along the panel scan line of the package containing 480 ${\times}$ 240 pixels. We designed the package structure of maximum 6.35 $\mu$s signal delays and 3360 ${\times}$ 780 pixels, and as a result we showed that the proper structure of 20 $\mu$m scan line width, 60$\mu$m panel TFT gate width and 8 $\mu$m gate length. This LCD_FRAME software tool provides results of the analysis and the design in the form of input files of the SPICE program, text data files, and graphic charts.

• Proceedings of the International Microelectronics And Packaging Society Conference
• /
• 2003.09a
• /
• pp.93-100
• /
• 2003

The continuing scaling trend in microelectronic circuit technology has a significant impact on the different IC interconnection and packaging technologies. These latter technologies have not kept pace with the IC scaling trends, resulting in a so-called“interconnect technology gap”. Multilayer thin film technology is proposed as a“bridge”- technology between the very high density IC technology and the coarse standard PCB technology. It is also a key enabling technology for the realisation of true“System-in-a-Package”(SIP) solutions, combining multiple“System-on-a-Chip”(SOC) IC's with other components and also integrating passive components in its layers. A further step is to use this technology to realise new functionalities on top of active wafers. These additional“above-IC”processed layers may e.g. be used for low loss, high speed on chip interconnects, clock distribution circuits, efficient power/ground distribution and to realize high Q inductors on chip.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.1097-1098
• /
• 2013

• Journal of Mushroom
• /
• v.11 no.4
• /
• pp.292-296
• /
• 2013

Recently, Pleurotus eryngii, King oyster mushroom is the main export item in South Korea mushroom industry. For appropriate transportation to Europe and USA markets, it is necessary to elucidate suitable conditions of storage and treatment of post-harvest during long time shipping. Whole mushrooms were packed with polypropylene anti-fog film (30 um) without trimming. The range of package weight and oxygen permeability of film were 200 g~400 g and 2000~5000 $cc/m^2$, 24 h,atm, respectively. The weight loss ratio was increased with increasing storage time. There were no big differences in weight loss ratio according to package weight and oxygen permeability of film at low temperature storage($4^{\circ}C$). In case of package weight is 400 g and oxygen permeability of film is 3000 $cc/m^2$, 24 h, atm. As a results of freshness, the optimum packing weight and oxygen permeability of film of P. eryngii were 400 g and below 2,000 $cc/m^2$, 24 h, atm, respectively.