• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.135-142
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• 2006

The package loading process of tile lumbering industry is an operation that after a pair of workers binds three or six lumber into a unit and cut the both ends of the lumber, carry and pack and load the weight cargo of 30-50kg. The package loading process causes lots of noise and wood dust when the lumber are cut and brings about the main cause of the musculoskeletal disorder when workers carry the heavy goods. Therefore, we developed the monolithic package loading equipment cutting both ends that is enable to improve the working method and environments of the existing package loading process. The noise and wood dust were reduced by developing the device and the main cause of shirking duties on working place was solved by preventing the musculoskeletal disorder and improving the working environments as excluding the work of carrying heavy goods.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.95-103
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• 2008

The package loading process of the lumbering industry is an operation that after a pair of workers bind three or six lumbers into one unit and cut both ends of the lumbers, transports the weight cargo of 30-50kg by one meter, pack and load at a height of 1.2 meters. This package loading process causes lots of noise and wood dust when workers carry out the heavy work as the above. Therefore we developed the monolithic both ends cutting package loading equipment in order to prevent from getting musculoskeletal disease. An loading bar working system of this equipment is improved from pneumatic pressure system to oil pressure system, furnished the newly designed flow dividers, and developed the new system that a both end array is loaded identically. Also we developed the safety equipment of loading bar in order to prevent workers mistake and overload from malfunction during the package loading process. The main cause of job evasion on working place could be solved by preventing the musculoskeletal disease and improving the working environments.

• Proceedings of the Safety Management and Science Conference
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• 2008.04a
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• pp.135-147
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• 2008

The package loading process of the lumbering industry is an operation that after a pair of workers bind three or six lumbers into one unit and cut both ends of the lumbers, transports the weight cargo of 30-50kg by one meter, pack and load at a height of 1.2 meters. This package loading process causes lots of noise and wood dust when workers carry out the heavy work as the above. Therefore we developed the monolithic both ends cutting package loading equipment in order to prevent from getting musculoskeletal disease. An loading bar working system of this equipment is improved from pneumatic pressure system to oil pressure system, furnished the newly designed flow dividers, and developed the new system that a both end array is loaded identically. Also we developed the safety equipment of loading bar in order to prevent workers mistake and overload from malfunction during the package loading process. The main cause of job evasion on working place could be solved by preventing the musculoskeletal disease and improving the working environments.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.43-50
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• 1998

The purpose of the paper is to protect the damage of plastic IC package with searching the cause of the fracture due to the delamination and crack when the encapsulant of plastic IC package is on viscoelastic behavior with the effect of creep on high temperature, The model for analysis is the plastic SOJ package with dimpled diepad in the IR soldering process of surface mounting technology. The risk of delamination with calculating the distribution of viscoelastic thermal stress in the package without the crack in the surface mounting process is checked. The package model with the perfect delamination between chip and diepad is chosen to estimate the resistance against fracture in thermal loading with calculating C (t)-integrals according to the change of the design. The optimum design to depress the delamination and crack is presented.

• Journal of Mechanical Science and Technology
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• v.18 no.3
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• pp.357-369
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• 2004

The purposes of the paper are to analyze the fracture phenomenon by delamination and cracking when the encapsulant of plastic IC package with polyimide coating shows viscoelastic behavior under hygrothermal loading in the IR soldering process and to suggest more reliable design conditions by the approaches of stress analysis and fracture mechanics. The model is the plastic SOJ package with the polyimide coating surrounding chip and dimpled diepad. On the package without cracks, the optimum position and thickness of polyimide coating to decrease the maximum differences of strains at the bonding surfaces of parts of the package are studied. For the model delaminated fully between the chip and the dimpled diepad, C(t)-integral values are calculated for the various design variables. Finally, the optimal values of design variables to depress the delamination and crack growth in the plastic IC package are obtained.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.51-59
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• 1998

The purposes of the paper are to consider the failure phenomenon based on delamination and crack when the encapsulant of plastic IC package under hygrothermal loading in the IR soldering process is on elastic and viscoelastic behavior due to the temperature and to show the optimum design using fracture mechanics. The model for analysis is the plastic SOJ package with a dimpled diepad. The package model with the perfect delamination between chip and diepad is chosen to estimate the resistance to fracture by calculating J-integrals in low temperature and C(t)-integrals in high temperature with the change of the design under hygrothermal loading. The optimum design to depress the delamination and crack in the plastic IC package is presented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.4
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• pp.1347-1355
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• 1996

The purpose of this paper is to evaluate the delamination and fracture integrity of the IC plastic package under hygrothermal loading by stress analysis and fracture mechanics approaches. The plastic SOJ package with a dimpled diepad under the reflow slodering process of IR heating type is considered. On the package without a crack, the stress variation according to the change of the design variables such as the material and shape of the package is calculated and the possibility of delamination is considered. For the model fully delaminated between the chip and diepad, J-integrals are calculated for the various design variables and the fracture integrity is discussed. From the results, optimal design values of variables to prevent the delamination and fracture of IC package are obtained. In this study, FDM program to obtain the vapor pressure from the content of moisture absorbed into the package is developed.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.608-612
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• 2007

FOTA는 무선기능이 장착된 Mobile Device에 새로운 Software에 대한 알림기능이 도착하면, Software가 탐재된 서버에 접속하여 Software를 Download 받고, 그 Download한 Software를 Upgrade 하는 기능을 말한다. FOTA 기능을 장착하기 위해서 Mobile Device는 Delta Package의 사이즈를 최소화하기 위한 특별한 Binary 구조를 가지는데 두 Binary의 차이를 압축한 것을 Delta Package라고 부르며, Binary 사이에 Upgrade를 위한 여분의 Gap을 두어, 향후 수정된 내용이 있을 때, 수정사항을 공간 내에 포함할 수 있도록 한다. 바이너리를 구성하는 Object들이 Image내에 어떤 위치에 포함될 것인지를 결정하는 Scatter Loader에 따라, Binary의 구조 및 확장성, Delta의 크기를 결정하게 되는데, 이것은 Object의 Type이나 Scatter Loading File내에서 명시한 순서와는 관계가 없고, Execution Region의 분할 개수를 늘릴수록, 각 Object의 Dependency 별로 묶을수록 Delta Size가 작아지는 것을 알게 되었다. 이 논문에서는 위에서 제시한 조건이 Delta Size에 미치는 원인에 대해 분석하고, Scatter Loading File을 최적화시킬 수 있는 방안에 대해서 연구한다.

• Tribology and Lubricants
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• v.21 no.2
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• pp.71-76
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• 2005

This paper compares of mechanical tensile properties of 6 kinds of copper foil. The beam lead made with copper foil. Different from other package type such as plastic package, Chip Size Package has a reliability problem in beam lead rather than solder joint in board level. A new tensile loading system was developed using voice-coil actuator. The new tensile loading system has a load cell with maximum capacity of 20 N and a non-contact position measuring system based on the principle of capacitance micrometry with 0.1nm resolution for displacement measurement. Strain was calculated from the measured displacement using FE analysis. The comparison of mechanical properties helps designer of package to choose copper for ensuring reliability of beam lead in early stage of semiconductor development.