• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.103-105
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• 2003

COG (Chip on Glass) technology using solder bump reflow has been investigated to attach IC chip directly on glass substrate of LCD panel. As It chip and LCD panel have to be heated to reflow temperature of the so]der bumps for COG bonding, it is necessary to use low-temperature solders to prevent the damage of liquid crystals of LCD panel. In this study, using the Sn-52In solder bumps of $40{\mu}m$ pitch size, solder joints between Si chip and glass substrate were made at temperature below $150^{\circ}C$. The contact resistance of the solder joint was $8.58m\Omega$, which was much lower than that of the joint made using the conventional ACF bonding technique. The Sn-52In solder joints with underfill showed excellent reliability at a hot humid environment.

• 센서학회지
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• 제20권1호
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• pp.58-63
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• 2011

A low loss radio frequency(RF) micro electro mechanical systems(MEMS) switch driven by a low actuation voltage was designed for the development of a new RF MEMS switch. The RF MEMS switch should be encapsulated. The glass cap and fabricated RF MEMS switch were assembled by the Au/Sn eutectic bonding principle for wafer-level packaging. The through-vias on the glass substrate was made by the glass dry etching and Au electroplating process. The packaged RF MEMS switch had an actuation voltage of 12.5 V, an insertion loss below 0.25 dB, a return loss above 16.6 dB, and an isolation value above 41.4 dB at 6 GHz.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.65-69
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• 2002

An Al film deposited on the Kovar alloy substrate was anodically-bonded to the borosilicate glass, and the bond interfaces was closely investigated by transmission electron microscopy. Al oxide was found to form a layer ~l0 nm thick at the bond interface, and fibrous structure of the same oxide was found to grow epitaxially in the glass from the oxide layer. The fibrous structure grew with the bonding time. The mechanism of the formation of this fibrous structure is proposed on the basis of the migration of Al ions under the electric field. Penetration of Al into glass beyond the interfacial Al oxide was not detected. The comparison of the amount of excess oxygen ions generated in the alkali depletion layer with that incorporated in the Al oxide suggests that the growth of the alkali-ion depletion layer is controlled by the consumption of excess oxygen to form the interfacial Al oxide.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.633-640
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• 1994

The tensile bond strength to dentin was measured for three glass-ionomer cement and composite resin combinations: two light-curing glass-ionomer cements(Vitrebond and XR - Ionomer) and one traditional glass - ionomer cement(Ketac - Bond), two adhesive systems(Scotchbond, and XR - Bonding System), and a corresponding composite resin. The bond strength of this "sandwich" was also compared with that of the same cements used in bulk. Vitredbond showed a significantly higher bond strength in bulk than did the other two cements. Of the sandwiches, the XR - Iomomer and XR - Bond combination showed a bond strength significantly higher than that of the Vitrebond and Scotchbond or Ketac- bond and Scotchbond combination. The fracture of the bond was mainly adhesive for Vitrebond, cohesive for XR - Ionomer when used in bulk and adhesive - cohesive when used in a sandwich, and cohesive for Ketac-Bond.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.815-820
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• 1998

Many composite girder bridges have been constructed for about thirty five years. Nowadays they are aged or deteriorated because of th increase in traffic and vehicle loads. In this study, the effect of strengthening with glass fiber sheet is investigated to estimate the possibility for appling for damaged prestressed concrete bridges. One normal and eight cracked specimens which had been preloaded were tested. The cracked specimens were strengthened with either external prestressing or bonding glass fiber sheet, or using both methods. The results showed that the maximum loads are almost same for both methods. So it seems that the strengthening with glass fiber sheet can be used for strengthening damaged prestressed concrete girders. It is important that proper devices should be selected to prevent glass fiber sheet from premature bonding failure below its maximum load, which is similar to end anchorage problem in external prestressing method. It is proved that the devices proposed in this paper have sufficient anchoring capability to increase load carrying capacity.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.423-426
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• 2005

A new chip on glass(COG) technique by making use of a high power diode laser for LCD driver IC packaging of LCD has been developed. A laser joining technology of the connection of IC chip to glass panel has several advantages over conventional method such as hot plate joining: shorter process time, high reliability of joining, and better fur fine pitch joining. The reach time to cure temperature of ACF in laser joining is within 1 second. In this study, results show that the total process time of joining is reduced by halves than that of conventional method. The adhesion strength is mainly 100-250 N/cm. It is confirmed that the COG technology using high power diode laser joining can be applied to advanced LCDs with a fine pitch.

• 센서학회지
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• 제12권6호
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• pp.265-272
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• 2003

본 논문은 파이렉스 #7740 유리 박막을 이용한 MEMS용 MLCA (Multi Layer Ceramic Actuator)와 Si기판의 양극접합 특성에 관한 것이다. 최적의 RF 마그네트론 스피터링 조건 (Ar 100%, input power $1\;W/cm^2$)하에서 MLCA기판위에 파이렉스 #7740 유리의 특성을 갖는 박막을 증착하였다. $450^{\circ}C$에서 1시간 열처리한 다음, -760 mmHg, 600V 그리고 $400^{\circ}C$에서 1시간동안 양극접합했다. 그 다음에 Si 다이어프램을 제조한 후, MLCA/Si 접합계면과 MLCA 구동을 통한 Si 다이어프램 변위특성을 분석 및 평가하였다. 다이어프램 형상에 따라 정밀한 변위 세어가 가능했으며 0.05-0.08 %FS의 우수한 선형성을 나타내었다. 또한, 측정동안 접합계면 균열이나 계면분리가 일어나지 않았다. 따라서, MLCA/Si기판 양각접합기술은 고성능 압전 MEMS 소자 제작공정에 유용하게 사용가능할 것이다.

• 센서학회지
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• 제16권5호
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• pp.325-330
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• 2007

For the application to optic devices, wafer level package including spacer with particular thickness according to optical design could be required. In these cases, the uniformity of spacer thickness is important for bonding strength and optical performance. Packaging process has to be performed at low temperature in order to prevent damage to devices fabricated before packaging. And if photosensitive material is used as spacer layer, size and shape of pattern and thickness of spacer can be easily controlled. This paper presents polymer bonding using thick, uniform and patterned spacing layer of SU-8 2100 photoresist for wafer level package. SU-8, negative photoresist, can be coated uniformly by spin coater and it is cured at $95^{\circ}C$ and bonded well near the temperature. It can be bonded to silicon well, patterned with high aspect ratio and easy to form thick layer due to its high viscosity. It is also mechanically strong, chemically resistive and thermally stable. But adhesion of SU-8 to glass is poor, and in the case of forming thick layer, SU-8 layer leans from the perpendicular due to imbalance to gravity. To solve leaning problem, the wafer rotating system was introduced. Imbalance to gravity of thick layer was cancelled out through rotating wafer during curing time. And depositing additional layer of gold onto glass could improve adhesion strength of SU-8 to glass. Conclusively, we established the coating condition for forming patterned SU-8 layer with $400{\mu}m$ of thickness and 3.25 % of uniformity through single coating. Also we improved tensile strength from hundreds kPa to maximum 9.43 MPa through depositing gold layer onto glass substrate.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.160-163
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• 2003

This paper describes on anodic bonding characteristics of MLCA(Multi Layer Ceramic Actuator) to Si-wafer using evaporated Pyrex #7740 glass thin-films for MEMS applications. Pyrex #7740 glass thin-films with same properties were deposited on MLCA under optimum RF magneto conditions(Ar 100 %, input power $1\;/cm^2$). After annealing in $450^{\circ}C$ for 1 hr, the anodic bonding of MLCA to Si-wafer was successfully performed at 600 V, $400^{\circ}C$ in - 760 mmHg. Then, the MLCA/Si bonded interface and fabricated Si diaphragm deflection characteristics were analyzed through the actuation test. It is possible to control with accurate deflection of Si diaphragm according to its geometries and its maximum non-linearity is 0.05-008 %FS. Moreover, any damages or separation of MICA/Si bonded interfaces do not occur during actuation test. Therefore, it is expected that anodic bonding technology of MICA/Si wafers could be usefully applied for the fabrication process of high-performance piezoelectric MEMS devices.

• 센서학회지
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• 제7권3호
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• pp.211-217
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• 1998

#7740 interlayer를 적용하여 Si 기관과 ITO가 코팅된 #7059 기판을 정전 열 접합하였다. SIMS 분석을 통하여 #7740 interlayer 내에 존재하는 $Na^{+}$ 이온들의 열-전기적 이동이 접합 메카니즘으로 작용함을 확인하였다. 우수한 접합을 얻기 위한 온도 및 전압 범위는 각각 $180{\sim}200^{\circ}C$ and $50{\sim}70V_{dc}$(10분)으로 나타났다. 이러한 저온 Si-ITO 코팅 유리 간의 접합 공정은 전계 방출 표시 소자의 패키징에 유용하게 이용될 수 있을 것으로 기대된다.