• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.10
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• pp.779-784
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• 2001

In this work, we studied the characteristics of nitride films for the optimization of PMD(pro-metal dielectric) linear process, which can be applied to the recent semiconductor manufacturing process. We split the deposit condition of nitride films into four parts such as PO(protect overcoat) nitride, baseline, low hydrogen and high stress and low hydrogen, respectively. We tried to find out correlation between BPSG deposition and densification. In order to analyze the changes of Si-H and Si-NH-Si bonding density, we used FTIR area method. We also investigated the crack generation on wafer edge after BPSG densification, and the changes of nitride film stress as a function of RF power variation to judge whether the deposited films.

• Journal of Powder Materials
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• v.14 no.1 s.60
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• pp.44-49
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• 2007

In the fabrication of dye-sensitized solar cells (DSSCs), carbon counter electrode has been tested for replacing the platinum counter electrode which has two drawbacks: limited surface area and high material cost. Poor mechanical stability of carbon layer due to weak bonding strength to electrically conductive TCO (transparent conducting oxide) glass substrate is a crucial barrier for practical application of carbon counter electrode. In the present study a carbon counter electrode with high conversion efficiency, comparable to Pt counter electrode, could be fabricated by adaption of a bonding layer between particulate carbon material and TCO substrate.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.79-85
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• 2003

In this study, the behavior characteristics of specimen strengthened with CFRP plate were analyzed according to the change of temperature. CFRP plate itself has a good resistance at the high temperature, but epoxy used as a adhesive is lost its bonding strength at the relatively low temperature. Therefore, this study carries out experiment on the beams slot-bonded with CFRP plates in order to maintain the successful bonding strength of epoxy at high temperature. It is presented that the range of glass transition temperature is 60-8$0^{\circ}C$ and RC beams slot-bonded with CFRP plate shows more increasing resistance and failure load than that of interface bonded at the high temperature.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.313-320
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• 2000

The purpose of this study was to evaluate on the interfacial morphology between dentin and restorative materials. In this in vitro study, the cavity wall restorated with 3 different kinds of tooth colored restorative materials [resin-modified Glass Ionomer cement (Fuji II LC), composite resin (Z-100), compomer (Dyract)]. The thirty extracted human molar teeth without caries and/or restorations are used. The experimental teeth were randomly divided into three groups of ten teeth each. In each group, Wedge shaped cavities (width: 3mm, length: 2mm, depth: 1.5mm) were prepared at the cementoenamel junction on buccal and lingual surfaces. The adhesive of composite resin were mixed with rhodamine B. Primer of composite resin, Prime & Bond 2.1 of Dyract and liquid of Fuji II LC were mixed with fluorescein. In group 1, the cavity wall was treatment with dentin conditioner, and then restorated with Fuji II LC. In group 2, the cavity wall was treatment with Prime & Bond 2.1 and then restorated with Dyract. In group 3, the cavity wall was etching with 10% maleic acid, applied with primer and bonding agent and then restorated with Z-100. The interface between dentin and restorative materials was observed by fluoresence imaging with a confocal laser scanning microscope. The results were as follows : 1. In Glass ionomer group, adaptation of resin modified Glass-ionomer restoration against cavity wall is tight, but the crack formed inside of restoration were observed. 2. In Dyract group, the penetration of resin tag is shorter and the width of hybrid layer is narrower than composite resin group. 3. In Z-100 group, primer penetrated deeply through dentinal tubule. Also bonding agent was penetrated along the primer, but the penetration length is shorter than primer part, and in 3-D image, the resin tag is conical shape and lateral branch is observed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.1033-1036
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• 2002

Wafer bonding methods such as fusion and anodic bonding suffer from high temperature treatment, long processing time, and possible damage to the micro-scale sensor or actuators. In the localized bonding process, beating was conducted locally while the whole wafer is maintained at a relatively low temperature. But previous research of localized heating has some problems, such as non-uniform soldering due to non-uniform heating and micro crack formation on the glass capsule by thermal stress effect. To address this non-uniformity problem, a new heater configuration is being proposed. By keeping several points on the heater strip at calculated and constant potential, more uniform heating, hence more reliable wafer bonding could be achieved. The proposed scheme has been successfully demonstrated, and the result shows that it will be very useful in hermetic packaging. Less than 0.2 ㎫ contact Pressure were used for bonding with 150 ㎃ current input for 50${\mu}{\textrm}{m}$ width, 2${\mu}{\textrm}{m}$ height and 8mm $\times$ 8mm, 5mm$\times$5mm, 3mm $\times$ 3mm sized phosphorus-doped poly-silicon micro heater. The temperature can be raised at the bonding region to 80$0^{\circ}C$, and it was enough to achieve a strong and reliable bonding in 3minutes. The IR camera test results show improved uniformity in heat distribution compared with conventional micro heaters. For gross leak check, IPA (Isopropanol Alcohol) was used. Since IPA has better wetability than water, it can easily penetrate small openings, and is more suitable for gross leak check. The pass ratio of bonded dies was 70%, for conventional localized heating, and 85% for newly developed FP scheme. The bonding strength was more than 30㎫ for FP scheme packaging, which shows that FP scheme can be a good candidate for micro scale hermetic packaging.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.399-406
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• 2000

The effect of inlay surface treatment on bonding was investigated when resin inlay was bonded to resin-modified glass-ionomer base with resin cement. For the preparation of glass-ionomer base, resin-modified glass-ionomer cement (Fuji II LC, GC Co., Japan) was filled in class I cavities of 7mm in diameter and 2mm in depth made in plastic molds. Eighty eight resin inlay specimens were made with Charisma$^{(R)}$ (Kulzer, Germany) and then randomly assigned to the four different surface treatment conditions: Group I, $50{\mu}m$ aluminium oxide sandblasting and silane treatment ; Group II, silane treatment alone ; Group III, sandblasting alone, and Group IV (control), no surface treatment. After a dentin bonding agent with primer (One-Step$^{TM}$, Bisco Inc., IL., U.S.A.) was applied to bonding surface of resin inlay and base, resin inlay were cemented to glass-ionomer base with a resin cement (Choice$^{TM}$, Bisco Inc., IL., U.S.A.). Shear bond strengths of each specimens were measured using Instron universal testing machine (4202 Instron, lnstron Co., U.S.A.) and fractured surfaces were examined under the stereoscope. Statistical analysis was done with one-way ANOVA and Dunkan's multiple range test. The results were as follows: 1. Sandblasting and silane treatment provided the greatest bond strength(10.56${\pm}$1.95 MPa), and showed a significantly greater bond strength than sandblasting alone or no treatment (p<0.05). 2. Silane treatment provided a significantly greater bond strength(9.77${\pm}$2.04 MPa) than sandblasting alone or no treatment (p<0.05). However, there was no significant difference in bond strength between sandblasting treatment and silane one (p>0.05). 3. Sandblasting alone provided no significant difference in bond strength from no treatment (p>0.05). 4. Stereoscopic examination of fractured surface showed that sandblasting and silane treatment or silane treatment alone had more cohesive failure mode than adhesive failure mode. 5. In relationship between shear bond strength and failure mode, cohesive failure occurred more frequently as bond strength increased.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.57-64
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• 2007

New Chip-on-glass technology to attach an Si chip directly on the glass substrate of LCD panel was studied with local heating method of the Si chip by using thin film heater fabricated on the Si chip. Square-shaped Cu thin film heater with the width of $150\;{\mu}m$, thickness of $0.8\;{\mu}m$, and total length of 12.15 mm was sputter-deposited on the $5\;mm{\times}5\;mm$ Si chip. With applying current of 0.9A for 60 sec to the Cu thin film heater, COG bonding of a Si chip to a glass substrate was successfully accomplished with reflowing the Sn-3.5Ag solder bumps on the Si chip.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.2
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• pp.13-20
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• 2008

This paper describes the methods of spacer-fabrication for wafer-level CIS(CMOS Image Sensor) assembly. We propose three methods using SU-8, PDMS and Si-interposer for the spacer-fabrication. For SU-8 spacer, novel wafer rotating system is developed and for PDMS(poly-dimethyl siloxane) spacer, new fabrication-method is used to bond with alignment of glass/PDMS/glass structure. And for Si-interposer, DFR(Dry Film Resist) is used as adhesive layer. The spacer using Si-interposer has the strongest bonding strength and the strength is 32.3MPa with shear.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1049-1050
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• 2009

• Korean Journal of Metals and Materials
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• v.46 no.9
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• pp.585-592
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• 2008

Flip-chip bonding using Cu-Sn mushroom bumps composed of Cu pillar and Sn cap was accomplished, and the contact resistance and the thermal cycling reliability of the Cu-Sn mushroom bump joints were compared with those of the Sn planar bump joints. With flip-chip process at a same bonding stress, both the Cu-Sn mushroom bump joints and the Sn planar bump joints exhibited an almost identical average contact resistance. With increasing a bonding stress from 32 MPa to 44MPa, the average contact resistances of the Cu-Sn mushroom bump joints and the Sn planar bump joints became reduced from $30m{\Omega}/bump$ to $25m{\Omega}/bump$ due to heavier plastic deformation of the bumps. The Cu-Sn mushroom bump joints exhibited a superior thermal cycling reliability to that of the Sn planar bump joints at a bonding stress of 32 MPa. While the contact resistance characteristics of the Cu-Sn mushroom bump joints were not deteriorated even after 1000 thermal cycles ranging between $-40^{\circ}C$ and $80^{\circ}C$, the contact resistance of the Sn planar bump joints substantially increased with thermal cycling.