• Journal of the Microelectronics and Packaging Society
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• v.26 no.3
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• pp.81-88
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• 2019

In this study, the effects of graphene oxide (GO) addition on electromigration (EM) lifetime of Sn-3.0Ag-0.5Cu Pb-free solder joint between a ball grid array (BGA) package and printed circuit board (PCB) were investigated. After as-bonded, $(Cu,Ni)_6Sn_5$ intermetallic compound (IMC) was formed at the interface of package side finished with electroplated Ni/Au, while $Cu_6Sn_5$ IMC was formed at the interface of OSP-treated PCB side. Mean time to failure of solder joint without GO solder joint under $130^{\circ}C$ with a current density of $1.0{\times}10^3A/cm^2$ was 189.9 hrs and that with GO was 367.1 hrs. EM open failure was occurred at the interface of PCB side with smaller pad diameter than that of package side due to Cu consumption by electrons flow. Meanwhile, we observed that the added GO was distributed at the interface between $Cu_6Sn_5$ IMC and solder. Therefore, we assumed that EM reliability of solder joint with GO was superior to that of without GO by suppressing the Cu diffusion at current crowding regions.

• Advances in nano research
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• v.2 no.3
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• pp.157-172
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• 2014

The three-dimensional Nano-Electronic Modeling toolkit (NEMO 3-D) is an open source software package that allows the atomistic calculation of single-particle electronic states and optical response of various semiconductor structures including bulk materials, quantum dots, impurities, quantum wires, quantum wells and nanocrystals containing millions of atoms. This paper, first, describes a software module introduced in the NEMO 3-D toolkit for the calculation of electronic bandstructure and interband optical transitions in nanowires having wurtzite crystal symmetry. The energetics (Hamiltonian) of the quantum system under study is described via the tight-binding (TB) formalism (including $sp^3$, $sp^3s^*$ and $sp^3d^5s^*$ models as appropriate). Emphasis has been given in the treatment of surface atoms that, if left unpassivated, can lead to the creation of energy states within the bandgap of the sample. Furthermore, the developed software has been validated via the calculation of: a) modulation of the energy bandgap and the effective masses in [0001] oriented wurtzite nanowires as compared to the experimentally reported values in bulk structures, and b) the localization of wavefunctions and the optical anisotropy in GaN/AlN disk-in-wire nanowires.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.150-157
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• 2010

We proposed a $4{\times}8$ array antenna with aperture-coupled patch antenna elements. The antenna was designed for 60 GHz operation and fabrication on the low-temperature cofired ceramic(LTCC) substrate($\varepsilon_r$=5.8). The feedline with the stub was designed to enhance the radiating element bandwidth and the transition characteristics between the waveguide (WG) and microstrip line(MSL). Through the optimization of the antenna and feedline geometry, the antenna gain and the performance of the 10 dB bandwidth were 20.2 dBi and 13 % up, respectively. The measured results agreed with the simulated ones.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.53-58
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• 2003

The Wafer Level Packaging is one of the most important technologies in the semiconductor industry today. Its primary advantages are its small form factor and low cost potential for manufacturing including test procedure. The CASIO's WLP samples, application example and the structure are shown in Fig.1, 2&3. There are dielectric layer , under bump metal, re-distribution layer, copper post , encapsulation material and terminal solder .The key technologies are 'Electroplating thick copper process' and 'Unique wafer encapsulation process'. These are very effective in getting electrical and mechanical advantages of package. (Fig. 4). CASIO and CMK are developing a new System Packaging technology called the Embedded Wafer Level Package (EWLP) together. The active components (semiconductor chip) in the WLP structure are embedded into the Printed Wiring Board during their manufacturing process. This new technical approach has many advantages that can respond to requirements for future mobile products. The unique feature of this EWLP technology is that it doesn't contain any solder interconnection inside. In addition to improved electrical performance, EWLP can enable the improvement of module reliability. (Fig.5) The CASIO's WLP Technology will become the effective solution of 'KGD problem in System Packaging'. (Fig. 6) The EWLP sample shown in Fig.7 including three chips in the WLP form has almost same structure wi_th SoC's. Also, this module technology are suitable for RF and Analog system applications. (Fig. 8)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1098-1106
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• 2007

This paper presents active antenna diplexers implemented into an ultra-wideband CPW(Coplanar Waveguide) fed monopole antennas. The proposed active antenna diplexer is designed to direct interconnect the output port of a wideband antenna to the input port of two active(HEMT) devices, where the impedance matching conditions of the proposed active integrated antenna are optimized by adjusting CPW(Coplanar Waveguide) feed line to be the length of 1/20 $\lambda_0$(@5.8 GHz) in planar type wideband antenna. The measured bandwidth of the active integrated antenna shows the range from 2.0 GHz to 3.1 GHz and from 5.25 GHz to 5.9 GHz. The measured peak gains are 17.0 dB at 2.4 GHz and 15.0 dB at 5.5 GHz.

• ETRI Journal
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• v.26 no.6
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• pp.589-596
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• 2004

Packaging technologies for a broadband and narrowband modulator with a traveling wave electro-absorption modulator (TWEAM) device were developed. In developing a broadband modulator, the effects of the device and packaging designs on the broadband performance were investigated. The optimized designs were obtained through a simulation with the result that we developed a broadband modulator with a 3 dB bandwidth of 38 GHz in the electrical-to-optical (E/O) response, an electrical return loss of less than -10 dB at up to 26 GHz, an rms jitter of 1.832 ps, and an extinction ratio of 5.38 dB in a 40 Gbps non-return to zero (NRZ) eye diagram. For analog application, the effect of the RF termination scheme on the fractional bandwidth was studied. The microstrip line with a double stub as a matching circuit and a laser trimming process were used to obtain an $S_{11}$ of -34.58 dB at 40 GHz and 2.9 GHz bandwidth of less than -15 dB.

• Journal of the Microelectronics and Packaging Society
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• v.5 no.2
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• pp.21-26
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• 1998

대용량, 고속데이터 처리가 요구되는 System 개발은 이들의 복잡하고 고기능의 회 로 구현이 가능하냐에 달려 있고 또한 이들고기능 요구를 가장 잘 만족할수 있는 패키지는 MCM 이라 할 수있다. 시스템의 고속화, 소형화는 회로의 복잡성을 요구하는 있는 이를 패 키지로 구현하는 MCM은 시험성 확보에 심각한 문제점으로 나타나고 있다. 본 논문에서는 고밀도 구조의 MCM 기판에 대한 Interconnetion Line 시험검증을 위한 Flying Prober의 적 용 및 모듈 패키징 공정에 대한 조립성 검증을 위한 BST에 대해 설명한다. 연구에 사용된 MCM 모듈은 MCM-D 공정으로 제작되었으며 31um 신호선폭, 50um Via Hole Dia. 5신호 선층 5절연층 및 455 Net의 기판으로절연층은 Dow chemical의 BCB-4024/4026을 적용하였 다. 조립은 3 ASIC, 24소자 실장 및 2000 Wire Bonding으로 이루어지며 패키지는 방열특성 을 고려한 BGA(491 I /O,50mil pitch)를 개발하여 사용하였다. MCM 기판의미세패턴으로 구성된 Interconnection Line에 대해 Fine Ptich Probing이 가능한 Flying Prober를 사용하 여 평가하였으며 BST를 이용하여 실장소자의 KGD평가 및 능동, 수동소자가 실장된 MCM Package의 조립시험성을 확보할수 있었다.

• Food Science and Preservation
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• v.11 no.2
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• pp.195-200
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• 2004

Microbial lethal value and nutrient retention of sous vide processed spinach were evaluated with mathematical model prediction and experimental trial for different package sizes and pasteurization temperatures. The package size covers 500 g, 1 kg and 2 kg, while the pasteurization temperature includes 80, 90 and 97$^{\circ}C$. The basic process scheme consists of filling blanched spinach into barrier plastic film pouch, sealing under vacuum, pasteurization in hot water with over pressure and final cooling to 3$^{\circ}C$. Pasteurization condition was designed based on attainment of 6 decimal inactivation of Listeria monocytogenes at geometric center of the pouch package by heating cycle, which was determined by general method. Heat penetration property of the package and thermal destruction kinetics were combined to estimate the retention of ascorbic acid and chlorophyll. Smaller packages with shorter pasteurization time gave better nutrient retention, physical and chemical qualities. Larger package size was estimated and confirmed experimentally to give higher pasteurization value at center, lower ascorbic acid and chlorophyll contents caused by longer heat process time. Lower pasteurization temperature with longer process time was predicted to give lower pasteurization value at center and lower ascorbic acid, while chlorophyll content was affected little by the temperature. Experimental trial showed better retention of ascorbic acid and chlorophyll for smaller package and higher pasteurization temperature with shorter heating time. The beneficial effect of smaller package and higher pasteurization temperature was also observed in texture, color retention and drip production.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.07a
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• pp.127-133
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• 2001

Package reliability test was conducted to investigate the effect of solder composition on ball fatigue strength. The specimens are first assembled using eutectic Composition S $n_{62}$P $b_{36}$A $g_2$, S $n_{63}$P $b_{34.5}$A $g_2$S $b_{0.5}$ solder and Pre-conditioned at MRT Lv 2a and then conducted under Temperature Cycle test(TC). For each case, the ball shear strength is obtained and micro structure photos are taken. SEM and EDX are used to analyze failure mechanism. The degradation of shear strength of solder balls after reliability test is discussed.d.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.3
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• pp.117-123
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• 2018

Continued R&D investment by the government and corporate support played a major role as the background of the rapid growth of the Republic of Korea. In 2017 of the Republic of Korea, the R&D support size of the government accounted for 19.7 trillion won, accounting for 4.7% of the government budget. Government R&D budgets are increasing by 2.5% each year. In this paper, we analyzed the outcomes of the Busan regional company support project conducted in the 2 years. For the time series analysis, we gathered company support amount by year, sales after company support, employment. We used IBM SPSS(Statistical Package for the Social Sciences) statistics 18 for correlation analysis.