The application of flip chip technology has been growing with the trend of miniaturization of electronic packages, especially in mobile electronics. Currently, several types of adhesive are used for flip chip bonding and these adhesives require some special properties; they must be solvent-free and fast curing and must ensure joint reliability against thermal fatigue and humidity. In this study, imidazole and its derivatives were added as curing catalysts to epoxy resin and their effects on the adhesive properties were investigated. Non-isothermal DSC analyses showed that the curing temperatures and the heat of reaction were dependent primarily on the type of catalyst. Isothermal dielectric analyses showed that the curing time was dependent on the amount of catalysts added as well as their type. The die shear strength increased with the increase of catalyst content while the Tg decreased. From this study, imidazole catalysts with low molecular weight are expected to be beneficial for snap curing and high adhesion strength for flip chip bonding applications.

The Realization of Ubiquitous is achieved by magic mirror and it is required more concrete study to realize it's functionality. Especially its function of professional fashion co-ordinator for managing the appearance could be of further use. The Objective of this Study is to establish RFID chip data base to put into a computer for making use of the functionality of the magic mirror aiming at suggesting the available information on the total fashion co-ordination. I sought firstly the code with binary system determining the criteria of accessories to be input in a RFID chip. Secondly, as the image with cloth is an important element for the total fashion co-ordination, desired co-ordination among the emphasis, harmony, character, season and accent can be made selectable classifying into a limit element and a common element to extract the codes. Thirdly, necessary conditions were given to the generated codes using Visual C++ program of Microsoft and the extracted codes as per groups were compared and analyzed.

The design of a memory control chip is described which is intended for embedded operation in VLSI Chip for 3D image application. It consists of two SRAMs and memory controller. The two memories section and their address counters are being swapped from the storage to the call clock. The systems offers improved accuracy, repeatability, portability, and flexibility not available in current commercial systems. To reduced a chip, 4T(4 transistors) SRAM cells are used instead of the standard SRAM cells 6T (6 transistors) by which the leakage current is drastically reduced and low power is achieved. The layout of the memory chip is realized using Electric layout editor, the DRC and LVS is verified using Electric and post layout simulated with LT SPICE tool of computer.

본 논문은 골재부착력(aggregate retention) 평가를 통해서 칩실(chip seal)에서 사용되는 롤러 종류의 기초적인 연구 결과를 설명하고 있다. 입도 78M의 화강암 골재와 CRS-2 이멀젼(emulsion)을 사용하여 single layer 칩실 테스트 구간을 시공하였으며, 3개의 다른 롤러 종류를 사용하였다. 사용된 롤러 종류는 pneumatic tire roller, steel wheel roller, and combination roller를 사용하였다. 세 종류의 롤러의 성능을 효과적으로 연구하기 위해서는 시공현장으로부터 직접 테스트용 시편을 얻는 것이 매우 중요하기 때문에, 노스캐롤라이나 주, Bailey에 있는 New Sandy Hill Church Road에서 테스트 구간 설정하고 일반적인 노스캐롤라이나 주의 칩실시공 절차에 준하여 시공을 실시하였다. 테스트 구간에서 제작된 시편들을 실험실로 옮겨서 골재부착력(aggregate retention) 성능평가를 실시하였다. 골재의 부착력을 평가하기 위해서 flip-over test(FOT), Vialit test, and the third-scale Model Mobile Loading Simulator (MMLS3) 시험방법들을 채택하였다. 세 가지의 시험결과들과 시험시공 현장에서 관측된 육안조사를 통해서 다음과 같은 롤러 종류와 순서를 추천하게 되었다. pneumatic tire roller 와 combination roller를 함께 사용하며 처음에 pneumatic tire roller가 다짐을 한 뒤에 그 뒤를 combination roller가 다짐하는 순서로 다짐작업을 함으로써 칩실의 성능이 향상 되리라 사료된다.

본 연구는 회수 가능한 플라스틱 다단상자에 물류분야에서 주로 이용되는 UHF대역(900MHz)의 RFID 기술을 응용하기위해 플라스틱 다단상자에 금속 등의 내용물에 따라 인식률에 미치는 영향에 대해 논의 하고 RFID 칩의 삽입위치를 제안한다. 현재 수출용 물류에 사용되는 박스는 일회용 목재 팔레트를 이용 해 수출을 한 뒤 폐기하고 있는 실정이다. 일회용 목재 팔레트를 이용하는 수출업체는 폐기비용 발생으 로 인해 물류비가 증가하며 이는 가격경쟁력 면에서 뒤처지는 문제점뿐만 아니라 목재라는 특성상 수출 시 방역 및 위생문제에 노출, 외부 충격으로 인한 상자 및 상품의 파손위험 등의 단점이 있다. 많은 기업들이 신제품개발, 품질개선, 원가절감 등에 힘쓰고 있지만, 이들 중 대부분의 기업은 물류비용에 대한 인식이 결여되어있다. 따라서 본 연구에서 회수 가능한 플라스틱 다단상자에 RFID 기술을 응용해 기존의 나무상자의 단점을 해소하고 대체할 수 있는 방안을 제시하기 위해 실험을 통해 RFID 칩의 부착위 치를 실증적으로 연구하였다.

표면 플라즈몬 공명을 이용한 센서는 굴절계 기기의 일종으로서 높은 감도를 가질 뿐만 아니라 비표지 방식이라는 장점을 가지고 있다. 본 연구에서는 재래식 SPR 칩을 이용하여 시판 술 4종의 알코올 함량을 측정하였다. 또한, 재래식 SPR 칩의 감도를 개선하기 위하여 금 박막 위에 금으로 나노형상을 구축하여 나노형상 SPR 칩을 제조하여 모형 술에 대한 감도 개선 효과를 분석하였다. 재래식 SPR 칩을 이용하여 시판 술의 알코올 함량을 측정하기 위한 검량선을 개발하였을 때 시료를 전처리 하지 않고 그대로 측정하였을 때 가장 좋은 검량선을 얻을 수 있었다. 소주, 청주, 이과두주, 탁주 등 시판 술 4종에 대한 1차 회귀식의 검량식에서 결정계수는 각각 0.992, 0.933, 0.918, 그리고 0.984로 나타났다. 한편, 재래식 SPR 칩의 감도를 개선하기 위해 나노형상 SPR 칩을 제조하기 위하여 Langmuir-Blodgett(LB) 방법을 활용하였다. 본 연구에서는 수십 nm 두께의 금 박막을 바닥층으로 하여 그 위에 나노 크기의 실리카 입자를 단분자 층으로 덮어 형틀을 제조하고 다시 그 위에 금을 증착한 후 실리카 입자를 제거하는 방법으로 나노형상을 갖는 SPR 칩을 제조하였다. 나노형상 SPR 칩의 성능을 평가하였을 때 20% 알코올 함량을 가지는 모형 술에 대해서 바닥층의 두께가 50 nm, 나노형상에서 골의 깊이가 20 nm, 나노형상의 배열주기가 300 nm일 때 SPR의 감도가 가장 좋아서 95%의 감도 향상을 얻을 수 있었다. SPR의 감도는 칩과 관련된 인자, 시료의 종류 및 상태에 따라 다르게 나타날 수 있으므로 측정 목적에 알맞은 칩의 설계와 선택이 요구된다.

This article shows various factors that influence the thermal-cycling reliability of semiconductor devices utilizing the lead-on-chip (LOC) die attach technique. This work details how the modification of LOC package design as well as the back-grinding and dicing process of semiconductor wafers affect passivation reliability. This work shows that the design of an adhesion tape rather than a plastic package body can play a more important role in determining the passivation reliability. This is due to the fact that the thermal-expansion coefficient of the tape is larger than that of the plastic package body. Present tests also indicate that the ceramic fillers embedded in the plastic package body for mechanical strengthening are not helpful for the improvement of the passivation reliability. Even though the fillers can reduce the thermal-expansion of the plastic package body, microscopic examinations show that they can cause direct damage to the passivation layer. Furthermore, experimental results also illustrate that sawing-induced chipping resulting from the separation of a semiconductor wafer into individual devices might develop into passivation cracks during thermal-cycling. Thus, the proper design of the adhesion tape and the prevention of the sawing-induced chipping should be considered to enhance the passivation reliability in the semiconductor devices using the LOC die attach technique.

In present work, manufacturing technologies of titanium hydride powder were studied for recycling of titanium tuning chip and for this, attrition ball milling was carried out under H2 pressure of 0.5 MPa. Ti chips were completely transformed into TiH2 within several hundred seconds. Dehydrogenation process TiH2 powders is consist of two reactions: one is reaction of TiH2 to TiHx and the other decomposition of TiHx to Ti and H2. The former reaction shows relatively low activation energy and it is suggested that the reaction is caused by introduction of defects due to milling.

Calcium concentration in the bone resorption lacunae is high and is in the mM concentration range. Both osteoblast and osteoclast have calcium sensing receptor in the cell surface, suggesting the regulatory role of high extracellular calcium in bone metabolism. In vitro, high extracellular calcium stimulated osteoclastogenesis in coculture of mouse osteoblasts and bone marrow cells. Therefore we examined the genes that were commonly regulated by both high extracellular calcium and 1.25(OH)₂vitaminD₃(VD3) by using mouse oligo 11 K gene chip. In the presence of 10 mM [Ca²+]e or 10 nM VD3, mouse calvarial osteoblasts and bone marrow cells were co-cultured for 4 days when tartrate resistant acid phosphatase-positive multinucleated cells start to appear. Of 11,000 genes examined, the genes commonly regulated both by high extracellular calcium and by VD3 were as follows; 1) the expression of genes which were osteoclast differentiation markers or were associated with osteoclastogenesis were up-regulated both by high extracellular calcium and by VD3; trap, mmp9, car2, ctsk, ckb, atp6b2, tm7sf4, rab7, 2) several chemokine and chemokine receptor genes such as sdf1, scya2, scyb5, scya6, scya8, scya9, and ccr1 were up-regulated both by high extracellular calcium and by VD3, 3) the genes such as mmp1b, mmp3 and c3 which possibly stimulate bone resorption by osteoclast, were commonly up-regulated, 4) the gene such as c1q and msr2 which were related with macrophage function, were commonly down-regulated, 5) the genes which possibly stimulate osteoblast differentiation and/or mineralization of extracellular matrix, were commonly down-regulated; slc8a1, admr, plod2, lox, fosb, 6) the genes which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were commonly up-regulated; s100a4, npr3, mme, 7) the genes such as calponin 1 and tgfbi which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were up-regulated by high extracellular calcium but were down-regulated by VD3. These results suggest that in coculture condition, both high extracellular calcium and VD3 commonly induce osteoclastogenesis but suppress osteoblast differentiation/mineralization by regulating the expression of related genes.

Machinability improvement by the use of liquid nitrogen in cryogenic machining has been reported in various studies. This has been mostly attributed to the cooling effect of liquid nitrogen. However, No study has been found in discussion on whether liquid nitrogen possesses lubrication effect in cryogenic cutting. This paper presents lubrication mechanism related to chip microstructure. The friction reduction was further reflected In larger shear angle and less secondary deformation in the chip microstructures.

탄성 반도체 칩과 점탄성 접착제층의 계면에 존재하는 모서리 균열에 대한 응력확대계수를 조사하였다. 이러한 균열들은 자유 경계면 부근에 존재하는 응력 특이성으로 인해 발생할 수 있다. 계면 응력상태를 해석하기 위해서 시간 영역 경계요소법이 사용되었다. 작은 크기의 모서리 균열에 대한 응력확대계수가 계산되었다. 점탄성 이완으로 인해 응력확대계수의 크기는 시간이 경과함에 따라 작아진다.