• Electrical & Electronic Materials
• /
• v.10 no.6
• /
• pp.533-540
• /
• 1997

The microwave dielectric properties of ((P $b_{1-x}$ C $a_{x}$)Zr $O_3$ and (P $b_{0.63}$,C $a_{0.37-x}$ $M_{x}$)Zr $O_3$(M=Mg,Sr) ceramics were investigated. In (P $b_{1-x}$ C $a_{x}$)Zr $O_3$ (X=0.33~0.40) ceramics, high quality factor and small temperature coefficient of resonant frequency were obtain in (P $b_{0.63}$C $a_{0.37}$)Zr $O_3$with perovskite structure. In the case of (P $b_{0.63}$C $a_{0.37-x}$M $g_{x}$)Zr $O_3$ dielectric constant temperature coefficient of resonant frequency increased and quality factor decreased due to increase of polarization of A-O bonding. When replacing Ca ion with Sr ion with large ion radius, polarization decreased with increased of bonding length and thus dielectric constant and temperature coefficient of resonant frequency decreased.decreased.creased.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.23 no.4
• /
• pp.867-886
• /
• 1996

The purpose of this study was to evaluate the shearbond strength and resin-dentin interface of three different dentinal bonding systems in primary and permanent teeth. Thirty extracted human primary molars and premolars, which were non-carious and free of obvious defect, were selected for this study. All specimens were divided into six groups with two groups allocated for each of the three dentinal bonding system(All-bond 2, Scotchbond Multi-Purpose, Gluma bonding system). After completion of bonding composite to dentin using each tested dentin bonding system, bond strength measurement and histological observation were performed. The results are as follows: 1. All-bond 2 and Scotchbond Multi-Purpose, A good quality hybrid layer was identified, the morphology of which could be equated with the zone of H-E and Brown-Brenn staining. In Gluma bonding system, hybrid layer was very thin, and separated from the solid polymer. 2. All-bond 2 had the highest mean shearbond strength, followed by Scotchbond Multi-Purpose and Gluma bonding system in both primary and permanent teeth. There was no statistically significant difference between All-bond 2 and Scotchbond Multi-Purpose. Statistically significant difference could be found between Gluma bonding system and the other two groups(p<0.05). 3. The fracture patterns observed were mainly the mixture of adhesive failure and dentin dettachment pattern in All-bond 2 and Scotchbond Multi-Purpose while adhesive failure prevailed in Gluma bonding system.

• Journal of KSNVE
• /
• v.8 no.6
• /
• pp.1093-1102
• /
• 1998

The success of controllability of smart structures depends on the quality of the bonding along the interface between the main structure and the attached sensing and acuating elements. Generally, the analysis procedures neglect the effect of the interfacial bond layer or assume that this bond layer behaves like viscoelastic material. Three different bond layers. two modified epoxy adhesives, and one isocyanate adhesive were prepared for their toughness and moduli. Bond layer of the chosen adhesive provides an almost perfect bonding condition between the composite structure and the PZT while bended significantly like arrow-shape. The perfect bonding condition is tested by considering various material properties of the bond layers. and based on this perfect bonding condition, the effects of the interfacial bond layer on the dynamic behavior and controllability of the test structure is experimentally studied. Once the perfect bonding condition is achieved. dynamic effects of the bond layer itself on the dynamic characteristics of the main structure is negligible. but the contribution of the attached PZT elements on the stiffness of the multi-layered structure becomes significant when the thickness of the bond layer increased.

• Smart Structures and Systems
• /
• v.1 no.1
• /
• pp.47-61
• /
• 2005

A ring-shaped lead zirconate titanate (PZT) piezoceramic sensor has been integrated with the Langevin-type piezoceramic driver of an ultrasonic wire-bonding transducer to form a smart transducer for in-situ measurement of three essential bonding parameters: namely, impact force, ultrasonic amplitude and bond time. This sensor has an inner diameter, an outer diameter and a thickness of 12.7 mm, 5.1 mm and 0.6 mm, respectively. It has a specifically designed electrode pattern on the two major surfaces perpendicular to its thickness along which polarization is induced. The process-test results have indicated that the sensor not only is sensitive to excessive impact forces exerted on the devices to be bonded but also can track changes in the ultrasonic amplitude proficiently during bonding. Good correlation between the sensor outputs and the bond quality has been established. This smart transducer has good potential to be used in automatic process-control systems for ultrasonic wire bonding.

• Child Health Nursing Research
• /
• v.16 no.3
• /
• pp.220-229
• /
• 2010

Purpose: The purpose of this study was to describe quality of life in school age children and the relationship between quality of life and parenting attitude as perceived by children and parent-child communication pattern. Methods: Data were collected between May 26 and June 3, 2009 using self-report questionnaires from 148 pairs of children and their parents. The children were enrolled in 4th to 6th grades. The questionnaires included the Parental Bonding Instrument (PBI), Parent-Child Communication (PCC) Scale, and Pediatric Quality of Life Inventory (PedsQL). The data were analyzed using the SPSS WIN 17.0 program. Results: The Quality of Life (QOL) score for the children was significantly higher among children reporting higher parental bonding attitude (mother r=.38, father r=.34) and parent-child communication (mother r=.43, father r=.36). Results of multiple regression showed that factors significantly associated with QOL were academic achievement, caregiver available after school, parent-child communication, school satisfaction, relationship with peers, and birth order among siblings. Conclusion: Positive relationships and good communication with parents and satisfaction with school life were important factors associated with quality of life in school age children.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1994.11a
• /
• pp.206-209
• /
• 1994

This paper has been researched bondability of electronic devices, such as lead frame and thick film of Ag/Pd on an alumina substrate by different heat sources. To obtain the bonds with high quality, it is very important to control both the thermal distribution of the bonds and it stability, because electronics components is consist of different materials. Therefore, this paper clarifies not only heat mechanism of micro parallel gap resistance bonding method and pulse heat tip bonding method but also investigates selection of heat sources with micro-electronic materials for bonding. Finally, it is realzed fluxless bonding process with filler metal such as plating layers.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.733-736
• /
• 2007

We have proposed novel bonding technique of substrates for developing the flexible LCD with high quality. The gel type mixture of agarose and UV curable epoxy developed to obtain tight bonding ability and enhanced electro-optical characteristic simultaneously. This technique can be used to roll-to-roll process for fabricating the flexible LCDs.

• Journal of Sensor Science and Technology
• /
• v.29 no.5
• /
• pp.354-359
• /
• 2020

The high vacuum hermetic sealing technique ensures excellent performance of MEMS resonators. For the high vacuum hermetic sealing, the customization of anodic bonding equipment was conducted for the glass/Si/glass triple-stack anodic bonding process. Figure 1 presents the schematic of the MEMS resonator with triple-stack high-vacuum anodic bonding. The anodic bonding process for vacuum sealing was performed with the chamber pressure lower than 5 × 10^-6 mbar, the piston pressure of 5 kN, and the applied voltage was 1 kV. The process temperature during anodic bonding was 400 ℃. To maintain the vacuum condition of the glass cavity, a getter material, such as a titanium thin film, was deposited. The getter materials was active at the 400 ℃ during the anodic bonding process. To read out the electrical signals from the Si resonator, a vertical feed-through was applied by using through glass via (TGV) which is formed by sandblasting technique of cap glass wafer. The aluminum electrodes was conformally deposited on the via-hole structure of cap glass. The TGV process provides reliable electrical interconnection between Si resonator and aluminum electrodes on the cap glass without leakage or electrical disconnection through the TGV. The fabricated MEMS resonator with proposed vacuum packaging using three-layer anodic bonding process has resonance frequency and quality factor of about 16 kHz and more than 40,000, respectively.

• Journal of the Microelectronics and Packaging Society
• /
• v.21 no.2
• /
• pp.37-41
• /
• 2014

One of the important developments in next generation electronic devices is the technology for power delivery and heat dissipation. In this study, the Cu-to-Cu flip chip bonding process was evaluated using the square ABL power bumps and circular I/O bumps. The difference in bump height after Cu electroplating followed by CMP process was about $0.3{\sim}0.5{\mu}m$ and the bump height after Cu electroplating only was about $1.1{\sim}1.4{\mu}m$. Also, the height of ABL bumps was higher than I/O bumps. The degree of Cu bump planarization and Cu bump height uniformity within a die affected significantly on the misalignment and bonding quality of Cu-to-Cu flip chip bonding process. To utilize Cu-to-Cu flip chip bonding with ABL bumps, both bump planarization and within-die bump height control are required.

• Proceedings of the KWS Conference
• /
• 2000.04a
• /
• pp.283-286
• /
• 2000