• 마이크로전자및패키징학회지
• /
• 제27권1호
• /
• pp.1-7
• /
• 2020

The backside metallization process is typically used to attach a chip to a lead frame for semiconductor packaging because it has excellent bond-line and good electrical and thermal conduction. In particular, the backside metal with the Ag/Sn/Ag sandwich structure has a low-temperature bonding process and high remelting temperature because the interfacial structure composed of intermetallic compounds with higher melting temperatures than pure metal layers after die attach process. Here, we introduce a die attach process with the Ag/Sn/Ag sandwich structure to apply commercial semiconductor packages. After the die attachment, we investigated the evolution of the interfacial structures and evaluated the shear strength of the Ag/Sn/Ag sandwich structure and compared to those of a commercial backside metal (Au-12Ge).

• 소성∙가공
• /
• 제19권1호
• /
• pp.32-37
• /
• 2010

Hydroforming has attracted a great deal of attention in the manufacturing industries for vehicles and transportation systems. Hydroforming technology contributes to weight reduction, increased strength, improved quality and reduced tooling cost. Hydroformed automotive parts used as structure components in vehichle body frame often have to be structurally joined at some point. Therefore it is useful if the hydroformed automotive parts can be given a localized attachment flange. For a given flange shape, a parting plane for the dies is established relative to which the various surfaces of the flange shape, in cross section, have no significant reverse curvature. In this study, hydroforming process for flange forming was proposed. FE analysis to form flanged circular shape and flanged rectangular shape was preformed with Dynaform 5.5. To accomplish successful hydroforming process design, thorough investigation on proper combination of process parameters such as tool geometry and hydraulic pressure has been performed and optimized. The results show that flanged automotive parts can be successfully produced with tube hydroforming.

• 한국안전학회지
• /
• 제6권4호
• /
• pp.53-57
• /
• 1991

Engineers of building construction have made efforts to produce more convinient building of good quality through the development of technology and raw materials nowadaye. This study is conducted to recognize problems of exterior tiles through experiments on quality of tiles according to sizes, and to find out and Iecommend most suitaff sizes of tiles. The sizes which are used widely in Construction field are selected as,45$\times$45mm, 57$\times$87mm, 60$\times$108mm, 60$\times$187mm, 96$\times$200mm. Ready mixed compound are used as mortar and Compressed attachment method are used.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
• /
• pp.613-616
• /
• 2001

This SF6 gas is widely used in industrial of insulation field. In this paper, N2 is mixed to improve pure SF6 gas characteristics. Electron transport coefficients in SF6-N2 mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results of this method, which are like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient, and critical EIN, can be important data to present characteristic of gas for insulation. Specially critical E/N is a data to evaluate insulation strength of a gas and is presented in this paper for various mixture ratios of SF6-N2 mixture gases.?⨀␍?܀㘱〮㜳㬓M敤楣楮攠慮搠桥污瑨

• 대한정형도수물리치료학회지
• /
• 제7권2호
• /
• pp.57-64
• /
• 2001

Plantar fasciitis is a common pathological condition of the foot and often be a challenge for clinicans to successfully treat. The purpose of this article is to present and discuss selected literature on the function and anatomy, causes, symptoms and clinical treating methods of plantar fasciitis. A majority of patients with plantar fasciitis present with either a pronated or a cave foot. Pain is usually localized to the plantar medial heel at the attachment of the plantar fascia to the calcaneus. Surgical and nonsurgical techniques have been used in the treatment of plantar fasciitis. Nonsurgical management for the treatment of the symptoms and discomfort associated with plantar fasciitis can be classified into brod categories: reducing pain and inflammation. reducing tissue stress to a tolerable level, and restoring muscle strength and flexibility of involved tissue.

• 한국영어학회지:영어학
• /
• 제3권4호
• /
• pp.547-570
• /
• 2003

There are a fair number of suffixes in English whose conditions on attachment refer to stress and/or segmental information contained within the words they attach to (see Siegel 1974, Jespersen 1942 and Marchand 1969). Through a wide study of relevant data, we will delve deeply into such phonological restrictions on the bases, which may as well be divided into four distinct types: haplological constraints; segmental constraints; prosodic constraints; and mixed types. We will further assume here that the category/ subcategorization requirements of affixes are subject to the Projection Principle (PP) as conceived in Kiparsky (1983). It will be shown how this PP interacts with phonological constraints placed upon the affix in question, especially in the treatment of-ful (inventful/mournful) or -en (longen/lengthen). Our account of problematic affixations in English is based on a number of violable constraints in OT.

• Bulletin of the Korean Chemical Society
• /
• 제33권1호
• /
• pp.248-254
• /
• 2012

During the monolayer assembly of zeolite microcrystals using sonication with stacking (SS) method, the factors that govern the degree of close packing (DCP) between the microcrystals, the rate of attachment (rA) of microcrystals onto the substrate, the degree of coverage (DOC), and the binding strength (BS) between each crystal and the substrate were investigated for each mode of binding linkage (MBL). The tested MBLs were covalent linkage (CL), ionic linkage (IL), and polyelectrolyte-mediated ionic linkage (p-IL). Unlike the monolayers of zeolite crystals assembled on glass with a covalent linkage, the strong BS, very high DOC, and very high DCP do not decrease during monolayer assembly on glass through ionic linkages. This results indicate that the surface migration of crystals undergo linkage-nondestructively when crystals were attached to the substrates through ionic linkages.

• 한국해양공학회지
• /
• 제22권3호
• /
• pp.103-108
• /
• 2008

Topics discussed in this paper are engineering design of artificial reefs, design considerations of compressive strength and pH, materials of silica fume concrete and volcanic stones for reef construction, and field monitoring of artificial reefs. Six artificial reefs were deployed offshore at Biyangdo in July 2006, and succession patterns on the reefs were investigated bimonthly from July 2006 to October 2007. The spore-bag method, which has been widely used in Korea for the attachment of seaweed on artificial reefs, was applied to the developed reefs using the kelp Ecklonia cava, which is the dominant species in Jeju, and recruitment and growth patterns were observed.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 추계 학술논문 발표대회
• /
• pp.163-164
• /
• 2018

In this study, the adhesion performance of the adhesive between the concrete base and the fiber panel was verified through experiments. Attachment to all three types by applying adhesive to panel and attaching to CRC board surface, method of applying adhesive to CRC board surface by panel, method of applying adhesive on panel and CRC board surface respectively, As a result of the performance test, the adhesive strength of the panel attached to the panel on the CRC board after the application of the adhesive was highest on both the back surface of the panel and the surface of the CRC board.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
• /
• pp.65-68
• /
• 2004

In the seismical capacity evaluation for RC structure wall-slab joint is very important factor. Because lateral load is resistance element and gravity load resistance element are acted mutually in the wall-slab joint. In this paper, to improve the seismic capacity of the wall-slab joint in the existing wall type apartments experiment which improve and retrofit a seismic capacity by unequal angle bracing and carbon sheet attachment are carried out. These methods are also economic and simple in mitigating seismic hazard, improve earthquake-resistance performance, and reduce risk level of building occupants. From the experimental results, the change of strength, degration of stiffness, and energy dissipation are evaluated. It can be concluded that these methods are effective in improving the seismic performance.