• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.1-6
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• 2016

The Internet of Things (IoT) is a new technology paradigm demanding one packaged system of various semiconductor and MEMS devices. Therefore, the development of electronic packaging technology with very high connectivity is essential for successful IoT applications. This paper discusses both fan-out wafer level packaging (FOWLP) and 3D stacking technologies to achieve the integrattion of heterogeneous devices for IoT. FOWLP has great advantages of high I/O density, high integration, and design flexibility, but ultra-fine pitch redistribution layer (RDL) and molding processes still remain as main challenges to resolve. 3D stacking is an emerging technology solving conventional packaging limits such as size, performance, cost, and scalability. Among various 3D stacking sequences wafer level via after bonding method will provide the highest connectivity with low cost. In addition substrates with ultra-thin thickness, ultra-fine pitch line/space, and low cost are required to improve system performance. The key substrate technologies are embedded trace, passive, and active substrates or ultra-thin coreless substrates.

• Journal of the Semiconductor & Display Technology
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• v.17 no.4
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• pp.42-45
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• 2018

As The semiconductor decrease from 10 nanometer to 7 nanometer, It is suggested that "More than Moore" is needed to follow Moore's Law, which has been a guide for the semiconductor industry. Fan-Out Wafer Level Package(FOWLP) is considered as the key to "More than Moore" to lead the next generation in semiconductors, and the reasons are as follows. the fan-out WLP does not require a substrate, unlike conventional wire bonding and flip-chip bonding packages. As a result, the thickness of the package reduces, and the interconnection becomes shorter. It is easy to increase the number of I / Os and apply it to the multi-layered 3D package. However, FOWLP has many issues that need to be resolved in order for mass production to become feasible. One of the most critical problem is the warpage problem in a process. Due to the nature of the FOWLP structure, the RDL is wired to multiple layers. The warpage problem arises when a new RDL layer is created. It occurs because the solder ball reflow process is exposed to high temperatures for long periods of time, which may cause cracks inside the package. For this reason, we have studied warpage in the FOWLP structure using commercial simulation software through the implementation of the reflow process. Simulation was performed to reproduce the experiment of products of molding compound company. Young's modulus and poisson's ratio were found to be influenced by the order of influence of the factors affecting the distortion. We confirmed that the lower young's modulus and poisson's ratio, the lower warpage.

• Asia-Pacific Journal of Business
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• v.7 no.1
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• pp.1-10
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• 2016

This study attempts to investigate the effects of different types of debts on economic growth in Bangladesh using time series data spanning from 2000 to 2015. In this study, the RDL model has been applied to determine the long run relationship among the selected variables. The result of the ARDL model shows that there exists a long term relationship between economic growth and the debt variables. It was evident from the findings that there exists bidirectional causality between public sector external debt and economic growth. Causality between private external debt and economic growth has been found to be insignificant. However, causality between domestic debt and economic growth showed a unidirectional causality from domestic debt to economic growth and not vice versa. Causality tests suggest that impact of domestic debt on economic growth is more effective compared to external debts.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.526-532
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• 2005

Representation of product data for exchanging and sharing a plant information was established the International Standard by ISO 10303 (STEP) and ISO 15926, but is not used widely in industrial circles by massiveness of standard and complexity of plant itself Specially, they are embodied to STEP data file(ISO 10303 Parts 21), but STEP file is uncomfortable that a person recognizes, and needs specification creation tool. In this paper, we made the integration schema for control valve through related standards, Also, we suggest the practical use framework for electronic commerce to utilize the XML schema that can represents integrate schema of control valve to use XML that is becoming the latest issue.

• Korean Journal of Computational Design and Engineering
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• v.13 no.2
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• pp.98-108
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• 2008

Plant, civil engineering and construction equipment data of overseas construction are obtained and then analyzed, classified and integrated by experts. With those refined data set, we built classification system and defined property information with reference to international standard (ISO 15926, IRDL). If class in ISO 15926 is predefined for equipment of interest, we used the class as is. If not, we created and defined new classes on the basis of ISO 15926 classes. If there is similar class for equipment of interest, extension or inheritance methods were used. As a result, classification system of five levels and 637 classes were built and construction equipment information were expressed in open structure of XML such as tree structure of classification system and detailed information with number equipments for each specific equipment. We also developed the electronic catalog system which is basically equipment information management system providing various product search functions.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.477-480
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• 2007

국제표준규격인 ISO 10303(STEP), ISO 13584(PLIB), ISO 15926을 연구하고 해외건설 플랜트의 기자재 데이터를 입수하여 전문가를 통한 분석, 분류 및 국제표준규격(ISO 15926 RDL) 기반과 비교하여 분류체계 구축 및 속성정보 정의 작업을 수행하였다. 통합 및 분리가 필요한 기자재 클래스에 대해서는 통합, 분리 작업을 수행하였고 적용 가능한 속성정보가 있을 경우는 클래스별로 확장 적용하였다. 이에, 5단계 레벨, 637개의 분류체계가 구성되었고 개방형 구조의 XML으로 플랜트 기자재 정보를 구축하여 계층구조 분류트리 표현 및 해당 기자재의 제품에 대한 상세 정보를 나타내었다. 또한, 제품정보를 통합검색, 카테고리검색, 상세검색, 논리검색 기능으로 검색, 확인할 수 있고 표준 및 제품, 업체, 시스템을 관리하는 기자재 정보 관리 시스템을 구현하였다.

• Archives of Metallurgy and Materials
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• v.66 no.3
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• pp.741-744
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• 2021

Selective deposition was performed on a micrometer trench pattern using a microcontact printing (μCP) process. Alkanethiols required for selective deposition were analyzed according to the carbon chain by linear sweep voltammetry (LSV). According to the LSV analysis, the effect of inhibiting Cu deposition depending on the length of the carbon chain was observed. During the Cu electrodeposition, the trench could be filled without voids by additives (PEG, SPS, JGB) in the plating solution. A μCP process suppressing the deposition of the sample was used for selective Cu electrodeposition. However, there was oxidation and instability of the sample and 1-hexadecanethiol in air. To overcome these problems, the μCP method was performed in a glove box to achieve effective inhibition.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.1
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• pp.37-43
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• 2020

The effects of O₂ plasma pre-treatment and post-annealing conditions on the interfacial adhesion of Ti thin film and WPR dielectric were investigated using 90° peel test for fan-out wafer level packaging (FOWLP) redistribution layer (RDL) applications. Peel strength between Ti film and WPR dielectric decreased from 8.9±1.3 g/mm to 2.7±0.9 g/mm for variation of O₂ plasma pre-treatment time from 30s to 300s, which is closely related to C-O-C or C=O bonds breakage at the WPR dielectric surface due to excessive plasma pre-treatment conditions. During post-annealing at 150℃, the peel strength abruptly decreased from 0 h to 24 h, and then maintained constant until 100 h, which is also mainly due to the damage of WPR dielectric which is weak to high temperature. Therefore, the optimum plasma pre-treatment conditions on the surface of dielectric is essential to interfacial reliability of FOWLP RDL.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.2
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• pp.41-48
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• 2018

The quantitative interfacial adhesion energy measurement method of copper redistribution layer and WPR dielectric interface were investigated using $90^{\circ}$ peel test, 4-point bending test, double cantilever beam (DCB) measurement for FOWLP Applications. Measured interfacial adhesion energy values of all three methods were higher than $5J/m^2$, which is considered as a minimum criterion for reliable Cu/low-k integration with CMP processes without delamination. Measured energy values increase with increasing phase angle, that is, in order of DCB, 4-point bending test, and $90^{\circ}$ peel test due to increasing roughness-related shielding and plastic energy dissipation effects, which match well interfacial fracture mechanics theory. Considering adhesion specimen preparation process, phase angle, measurement accuracy and bonding energy levels, both DCB and 4-point bending test methods are recommended for quantitative adhesion energy measurement of RDL interface depending on the real application situations.

• Journal of Ginseng Research
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• v.12 no.1
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• pp.1-10
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• 1988

Panax ginseng seedlings were grown at various temperature regimes from 15 to $30^{\circ}C$ for 19 days under dark and the linear relationship between various regrowth efficiencies and thermal stress indices, cumulative superoptimum temperatures corrected with factors. Gross growth efficiency(shoot weight l root weight loss) was 37.5 % at the optimum temperature $15^{\circ}C$/$15^{\circ}C$, and 12.3% at the highest temperature, $30^{\circ}C$/$30^{\circ}C$ while net growth efficiency (shoot weight + Sm)l(root loss-Rm), which corrected by maintenance respiration for shoot(Sm) and root(Rm) was 39.6% and 16.7 at optimum and highest temperature respectively. All growth efficiencies showed negative correlations (p = 0.001) with all thermal stress indices and negative(p = 0.001) with shoot growth(St). When growth temperature difference in a day was nil or above $15^{\circ}C$ growth efficiency decreased greatly. Thermal stress indices showed negative correlation with root dry matter loss(RDL) but positive with Rm. St showed positive correlation with RDL. Thermal stress appeared to inhibit substrate supply for shoot growth resulting in the extremely low growth efficiency comparing with other crops that seems to be main rate limiting factor of slow growth, Thus it is necessary that growth efficiency and thermal stress must be elucidated in terms of metabolic pathway.