• Transactions on Electrical and Electronic Materials
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• v.2 no.3
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• pp.28-32
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• 2001

It was studied in the present work how the thermal cycling performance of LOC (lead on chip) packages depends on the package construct or leadframe materials. First, package body thickness and Au wire diameter were manipulated for the selection of proper package design. Secondly, two different types of leadframe materials (i.e. copper and 52%Fe-48%Ni alloy) were tested to determine the better material for improved reliability margin of plastically encapsulated microelectronic packages. This work shows that manipulating package body thickness was more effective than an increase of Au wire from 23$\mu\textrm{m}$ to 33$\mu\textrm{m}$ for the prevention of wire debonding failure. Further, this work indicates that the LOC packages including the copper leadframes can be more susceptible to thermal cycling reliability degradation due to chip cracking than those including the alloy leadframes.

• The monthly packaging world
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• s.139
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• pp.76-80
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• 2004

• Electronics and Telecommunications Trends
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• v.4 no.4
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• pp.17-33
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• 1989

Hermetic 패키지는 재질 특성상 Plastic 패키지보다 환경내구성이 우수하고 수명이 긴 장점이 있으나, 가격이 높고 사용자의 주문에 의한 수작업으로 수급이 어려운 단점이 있다. 한편 Plastic 패키지는 가격이 낮고 수급이 용이한 반면 환경 특히 습기로 인한 고장으로 Hermetic 패키지보다 신뢰도가 낮아서 고신뢰도를 요구하는 군사용 및 산업용기기에서의 사용은 기피되어 왔다. 그러나 최근 Plastic 패키지의 단점을 개선하려는 노력으로 반도체칩의 수율 향상과 더불어 습기에 강한 재료가 개발되고 웨이퍼 제조기술이 발전됨에 따라 Plastic 패키지의 신뢰도가 향상되어 통신기기등 산업용 기기에까지 사용영역을 확대해 가고 있다. 또한 국내의 통신시장 개방에 따라 통신시스팀의 성능개선 및 신뢰성 제고를 통한 대외 경쟁력이 요구되어 통신시스팀에 Plastic 패키지 사용에 대한 인식이 증대하는 추세이다. 본고에서는 IC 패키지(Hermetic, Plastic)의 특성 및 성능을 비교 분석하고 이와 병행하여 Plastic 패키지의 최근 기술동향을 파악함으로써 통신시스팀에 사용하는 IC 패키지에 대한 고려사항을 제시하였다.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.2
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• pp.11-19
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• 2009

Thermo-mechanical behaviors of wire-bond plastic ball grid array (WB-PBGA) package assemblies are characterized by high-sensitivity moire interferometry. Using the real-time moire setup, fringe patterns are recorded and analyzed for several temperatures. Experiments are conducted for three types of WB-PBGA package that have full grid pattern and perimeter pattern with/without central connections. Bending deformations of the assemblies and average strains of the solder balls are investigated, with an emphasis on the effect of solder interconnection grid patterns, Thermal strain distributions and the location of the critical solder ball in package assemblies are quite different with the form of solder ball grid pattern. For the WB-PBGA-PC, The largest of effective strain occurred in the inner solder ball of perimeter closest to the chip solder balls. The critical solder ball is located at the edge of the chip for the WB-PBGA-FG, at the most outer solder ball of central connections for the WB-PBGA-P/C, and at the inner solder ball closest to the chip for the WB-PBGA-P.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.6
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• pp.951-960
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• 1997

Package crack caused by the soldering process in the surface mounting plastic package is evaluated by applying the maximum energy release rate criterion. It could be shown that the crack propagation from the lower edge of the ie pad is easily occurred at the maximum temperature during the soldering process, where the pressure acting on the crack surface is assumed by the saturated vapor pressure at maximum temperature. The package crack formation depends on various parameters such as chip size, relative thickness, material properties, the moisture content and soldering temperature etc. The quantitative measure of the effects of the parameters could be easily obtained by using the taguchi's method which requires only a few kinds of combinations with such parameters. From the results, it could be obtained that the more significant parameters to effect the package reliability are the orders of Young's modulus, die pad size, down set, chip thickness and maximum soldering temperature.

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

• Journal of the Korean institute of surface engineering
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• v.49 no.5
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• pp.439-446
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• 2016

In 2015, a fin tube (Cu-Ni 70/30 alloy) of package type heat exchanger for navy vessel was perforated through the wall which led to refrigerant leakage. This failure occurred after only one year since its installation. In this study, cause of the failure was determined based on available documents, metallographic studies and computational fluid dynamics simulation conducted on this fin tube. The results showed that dimensional gap between inserted plastic tube and inside wall of fin tube is the cause of the swirling turbulent stream of sea water. As a result of combination of swirling turbulence and continuing collision of hard solid particles in sea water, erosion corrosion has begun at the end of inserted plastic tube area. Crevice corrosion followed later in the crevice between the outer wall of plastic tube and inner wall of fin tube. It was found that other remaining tubes also showed the same corrosion phenomena. Thorough inspection and prompt replacement will have to be accomplished for the fin tubes of the same model heat exchanger.

• Proceedings of the Materials Research Society of Korea Conference
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• 1995.11a
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• pp.3-3
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• 1995

Plastic IC encapsulation utilizing lead on chip(LOC) die attach technique allows higher device density per unit package area, and faster current speed and easter leadframe design. Nevertheless, since the top surface of the chip is directly attached to the area of the leadframe with a double-sided adhesive tape in the LOC package, it tends to be easily damaged by the leadframe, leading to limitation in its utilization. In this work, it is detailed how the damage of the chip surface occurs, and it is influenced and improved by the LOC construct.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.467-470
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• 2005

There are about 10 motors for tile actuator of the automation system in an auto-mobile recently. The performance of the motor-case is much related to the noise and the vibration of an auto-mobile Multi-Forming process is so much the better than existing deep-drawing or Multi-step forming by press by less cost, installation and staff. But there isn't the specific and general process design, so we aren't good at competition. So in the first step, I want to study about the core design for the multi-forming process. We can access by the elasto-plastic theory and the finite element method, and we use a commercial package of the Deform-2D and, Deform-3D which is based on three-dimensional elasto-plastic finite element, evaluated propriety oi the package. The evaluation of the package propriety was simulated by simple bending example. It was found the elasto-plastic theory was mostly in agreement with the simulation. We proposed that three type of section for the core and analyzed by finite element method (Deform-2D). We can get the best result with the ellipse type core. Then we apply the result of the preceding analysis to the finite element method (Deform-3D). In 3D-finite element analysis, we can get the result of 8/100mm-roundness. This result can help the improvement of the multi-forming process.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.1
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• pp.65-69
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• 2008

This work shows that the grinding-induced scratches formed on the back surface of silicon chips can highly influence the flexural strength of the chips. Meanwhile, in a case that excellent adhesion between the back surface and the plastic package body maintains, the flexural strength of plastic-encapsulated packages is not so sensitive to the geometry of the scratch marks. This article explains why such different flexural fracture behavior between bare chips and plastic-encapsulated chips appears.