• Journal of Mechanical Science and Technology
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• 제19권3호
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• pp.820-825
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• 2005

This paper proposes non-destructive ESPI technique to evaluate inside defects of semiconductor package quantitatively. Inspection system consists of ESPI system, thermal loading system and adiabatic chamber. The technique has high feasibility in non-destructive testing of semiconductor and gives solutions to the drawbacks in previous technique, time-consuming and the difficulty of quantitative evaluation. In result, most of defects are classified in delamination, from which it is inferred to the insufficiency of adhesive strength between layers and nonhomogeneous heat spread. The $90\%$ of tested samples have a delamination defect started at the around of the chip which may be related to heat spread design.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.450-452
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• 2001

In this paper, we proposed the automatic postal drop-off system based on the microprocessor board or PC. The weight of the small postal package is transmitted from the electronic scale and user-entered addresses and delivery rate are processed by the controller to calculate the fee. For 24 hour out-door operation and maintenance, non-cash payment methods such as credit card payment is used. The post stamp and receipt are printed by the thermal printer. For the electronic processing of the parcel, serial code is also printed on the stamp and receipts in bar code format. The parcel information obtained by the automatic postal drop-off system is transferred to remote central system by dial-up modem shared by the on site office. The proposed system and its control software are built for prototype model operation and the result met the design requirements. For real time processing, data reception through three serial ports is handled by interrupt routine. The proposed system is expected to be applied for commercial logistics system and pc automation system.

• 대한기계학회논문집A
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• 제33권4호
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• pp.380-387
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• 2009

The reliability concerns of solder interconnections in flip chip PBGA packages are produced mainly by the mismatch of coefficient of thermal expansion(CTE) between the module and PCB. Finite element analysis has been employed extensively to simulate thermal loading for solder joint reliability and deformation of packages in electronic packages. The objective of this paper is to study the thermo-mechanical behavior of FC-PBGA package assemblies subjected to temperature change, with an emphasis on the effect of the finite element model, material models and temperature conditions. Numerical results are compared with the experimental results by using $moir{\acute{e}}$ interferometry. Result shows that the bending displacements of the chip calculated by the finite element analysis with viscoplastic material model is in good agreement with those by $moir{\acute{e}}$ inteferometry.

• 한국전기전자재료학회논문지
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• 제13권10호
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• pp.805-811
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• 2000

Reliability of PBGA(plastic ball grid array) package is weak compared with normal plastic packages. The low reliability is caused by low resistance to the popcorn cracking, which is generated by moisture absorption in PCB(prited circuit board). In this paper, plasma treatment process was used and we analyzed its effects to interface adhesion. The contents of C and Cl decrease after plasma treatment but those of O, Ca, N relatively increase. The plasma treatment improves the adhesion between EMC(epoxy molding compound) and PCB(solder mask). The grade of improvement was over 100% Max, which depends on the properties of EMC. The RMS(root mean square) roughness value of the solder mask surface increases to plasma treatment. There is little difference of adhesion in RF power and treatment time.

• 대한기계학회논문집A
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• 제31권6호
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• pp.659-664
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• 2007

$Moire\'{e}$ interferometry is a useful technique to assess the reliability of electronic package because $Moire\'{e}$ interferometry can measure the whole-field and real-time deformations. The shear strain of a small crack site is important to the reliability assessment of electronic package. The optical limitation of $Moire\'{e}$ interferometry makes ambiguous the shear strain of a small area. An atomic force microscope (AFM) is used to measure the profile of a micro site. High resolution of AFM can apply to the $Moire\'{e}$ technique. AFM $Moire\'{e}$ technique is useful to measure the shear strain of a small area. In this research, the method to accurately measure the deformation of a small area by using AFM $Moire\'{e}$ is proposed. A phase-shifting method is applied to improve the resolution of AFM $Moire\'{e}$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1504-1505
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• 2007

In this paper, fully embedded high Dk BTO MIM capacitors have been developed into a multi-layered organic package substrate for low cost RF SOP (System on Package) applications. These embedded MIM capacitors were designed and simulated by using CST 3D EM simulators for finding out optimal geometries and verifying their applicability. The embedded MIM capacitor with a size of $550\;{\times}\;550\;um^2$ has a capacitance of 5.3pF and quality factor of 43 at 1.5 GHz, respectively. The measured performance characteristics were well matched with 3D EM simulated ones. Equivalent circuit parameters of the embedded capacitors were extracted for making a design library.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.262-263
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• 2007

In this paper, fully embedded and miniaturized diplexer has been designed, fabricated, and characterized for dual-band/mode CDMA handset applications. The size of the embedded diplexer is significantly reduced by embedding high Q circular spiral inductors and high DK MIM capacitors into low cost organic package substrate. The fabricated diplexer has insertion losses and isolations of -0.5 and -23dB at 824-894MHz and -0.7 and -22dB at 1850-1990MHz, respectively. Its size is 3.9mm$\times$3.9mm$\times$ 0.77mm (height). The fabricated diplexer is the smallest one which is fully embedded into low cost organic package substrate.

• 기록학연구
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• 제78호
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• pp.79-151
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• 2023

이 연구는 대한민국의 전자기록 장기보존정책의 현황을 분석하고 향후과제를 제시하는데 목적이 있다. 현재 전자기록 장기보존정책은 명확하게 성문화되어 있지는 않지만, 전자서명, 해시, 보존포맷과 장기보존패키지라는 기술요소로 구성된다고 할 수 있다. 각 기술요소를 순서대로 고찰해보고, 변화하는 디지털환경에서 현 정책과 기술의 한계를 분석하고 대안을 제시하였다.

• Journal of Welding and Joining
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• 제27권3호
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• pp.17-22
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• 2009

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2001년도 추계학술발표대회 개요집
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• pp.162-164
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• 2001