• Advances in concrete construction
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• v.14 no.2
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• pp.139-151
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• 2022

Filling materials poured into precast member joint are subjected to restraint stress by the precast member and joint reinforcement. The induced stress will likely cause cracks at early ages and performance degradation of the entire structure. To prevent these issues and design reasonable joints, it is very important to analyze and evaluate the restrained shrinkage cracks of filling materials at various restraint conditions. In this study, a new time zero-that defines the shrinkage development time of a filling material-is proposed to calculate the accurate amount of shrinkage. The tensile stresses and strengths at different ages were compared through the ring test (AASHTO PP34) to evaluate the crack potential of the restrained filling materials at various restraint conditions. The mixture which contained an expansive additive and a shrinkage reducing agent exhibited high resistance to shrinkage cracking owing to the high-drying shrinkage compensation effect. The high-performance, fiber-reinforced cement composite, and ultra-high-performance, fiber-reinforced cement composite yielded very high resistance to shrinkage and cracking owing to the pull-out property of steel fibers. To this end, multiple nonlinear regression analyses were conducted based on the test results. Accordingly, a modified tensile stress equation that considered both the geometric shape of the specimen and the intrinsic properties of the material is proposed.

• Korean Journal of Materials Research
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• v.22 no.7
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• pp.335-341
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• 2012

Recently, the demand for the miniaturization of printed circuit boards has been increasing, as electronic devices have been sharply downsized. Conventional multi-layered PCBs are limited in terms their use with higher packaging densities. Therefore, a build-up process has been adopted as a new multi-layered PCB manufacturing process. In this process, via-holes are used to connect each conductive layer. After the connection of the interlayers created by electro copper plating, the via-holes are filled with a conductive paste. In this study, a desmear treatment, electroless plating and electroplating were carried out to investigate the optimum processing conditions for Cu via filling on a PCB. The desmear treatment involved swelling, etching, reduction, and an acid dip. A seed layer was formed on the via surface by electroless Cu plating. For Cu via filling, the electroplating of Cu from an acid sulfate bath containing typical additives such as PEG(polyethylene glycol), chloride ions, bis-(3-sodiumsulfopropyl disulfide) (SPS), and Janus Green B(JGB) was carried out. The desmear treatment clearly removes laser drilling residue and improves the surface roughness, which is necessary to ensure good adhesion of the Cu. A homogeneous and thick Cu seed layer was deposited on the samples after the desmear treatment. The 2,2'-Dipyridyl additive significantly improves the seed layer quality. SPS, PEG, and JGB additives are necessary to ensure defect-free bottom-up super filling.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.591-594
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• 2003

In the present study, we developed a filling material composed of poly(lactic-co-glycolic) acid (PLGA) microspheres with applications in the treatment of facial wrinkle and urinary incontinence and studied the feasibility of injecting the filling materials in animal models for plastic surgical and urological applications. Former filling materials including Teflon, Silicon, and collagen have shown a few shortcomings such as inflammation reaction, particles migration or volume decrease. We injected PLGA microspheres into the subcutaneous dorsum of mice. Injected volume was constantly maintained after implanting. We hardly found either inflammation reaction or migration. This material overcomes the problems of the current filling materials and could be utilized as a new filling material for plastic surgical and urological applications.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.3
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• pp.37-42
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• 2007

Copper deposition studies have been actively studied since interests on 3D SiP were increased. The defects inside via can be easily formed due to the current density differences on entrance, bottom and wall of via. So far many different additives and current types were discussed and optimized to obtain void-free copper via filling. In this research acid cupric sulfate plating bath containing additives such as PEG, SPS, JGB, PEI and wave current applied electroplating were examined. The size and shape of grain were influenced by the types of organic additives. The cross section of specimen were analyzed by FESEM. When PEI was added, the denser copper deposits were obtained. Electroplaing time was reduced when 2 step via filling was employed.

• Korean Journal of Materials Research
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• v.16 no.9
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• pp.529-532
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• 2006

Sn-filled $Co_8Sb_{24}$ skutterudites were synthesized by the encapsulated induction melting process. Single ${\delta}-phase$ was successfully obtained by subsequent annealing and confirmed by X-ray diffraction analysis. Temperature dependences of Seebeck coefficient, electrical resistivity and thermal conductivity were examined from 300 K to 700 K. The positive Seebeck coefficient confirmed the p-type conductivity of the Sn-filled $Co_8Sb_{24}$. Electrical resistivity increased with increasing temperature, which shows that the Sn-filled $Co_8Sb_{24}$ skutterudite is a highly degenerate semiconductor. Thermal conductivity was reduced by Sn-filling because the filler atoms acted as phonon scattering centers in the skutterudite lattice. Thermoelectric figure of merit was enhanced by Sn filling and its optimum filling content was considered to be $z{\leq}0.5$ in the $Sn_zCo_8Sb_{24}$ system.

• Imaging Science in Dentistry
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• v.47 no.3
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• pp.189-197
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• 2017

Purpose: To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. Materials and Methods: Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. Results: There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos(P>.05). Conclusion: Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.

• Restorative Dentistry and Endodontics
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• v.33 no.2
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• pp.115-124
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• 2008

The purpose of this study was to measure the polymerization shrinkage and hygroscopic expansion of resin-based temporary filling materials and to evaluate microleakage at the interface between the materials and cavity wall. Five resin-based temporary filing materials were investigated: Fermit (Vivadent), Quicks (Dentkist), Provifil (Promedica), Spacer (Vericom), Clip (Voco). Caviton (GC) was also included for comparison. Polymerization shrinkage of five resin-based temporary filling materials was measured using the bonded disc method. For the measurement of hygroscopic expansion, the discs of six cured temporary filling materials were immersed in saline and a LVDT displacement sensor was used to measure the expansion for 7 days. For estimating of microleakage, Class I cavities were prepared on 120 extracted human molars and randomly assigned to 6 groups of 20 each. The cavities in each group were filled with six temporary filling materials. All specimens were submitted to 1000 thermocycles, with temperature varying from $5^{\circ}C/55^{\circ}C$. Microleakage was determined using a dye penetration test. The results were as follows: 1. Fermit had significantly less polymerization shrinkage than the other resin-based temporary fill ing materials. Fermit (0.22%) < Spacer (0.38%) < Quicks (0.64%), Provifil (0.67%), Clip (0.67%) 2. Resin-based temporary filling materials showed 0.43-1.1% expansion in 7 days. 3. Fermit showed the greatest leakage, while Quicks exhibited the least leakage. 4. There are no correlation between polymerization shrinkage or hygroscopic expansion and microleakage of resin-based temporary filling materials.

• Journal of Welding and Joining
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• v.31 no.3
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• pp.11-16
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• 2013

Through-silicon-via (TSV) is a major technology in microelectronics for three dimensional high density packaging. The 3-dimensional TSV technology is applied to CMOS sensors, MEMS, HB-LED modules, stacked memories, power and analog, SIP and so on which can be employed to car electronics. The copper electroplating is widely used in the TSV filling process. In this paper, the various Cu filling methods using the control of the plating process were described in detail including recent studies. Via filling behavior by each method was also introduced.

• Journal of the Korean Geosynthetics Society
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• v.13 no.2
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• pp.21-29
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• 2014

The use of filling material based on cement paste is inefficient at field construction because it needs a lot of the charging mass. In addition, it has environmental problem according to the large amount of cement use because its strength is also larger than criterion. The excavated soil with stabilizer can be used as the filling materials when the bored pile is constructed. Therefore, this paper describes field application of solidified soil for economical efficiency and environment-friendly. The static axial load tests and the load-transfer measurements were performed to examine the axial resistant behavior of the piles. As results, the flowability, segregation and bleeding, and bond strength of filling materials was a good performance than that of the existing cement paste. But the skin friction of pile by PDA was slightly decreased than that of the existing cement paste. However, as pile filling materials, and in terms of economics and environment, the applicability of filling material is considered very effective.

• Korean Journal of Metals and Materials
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• v.48 no.7
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• pp.667-673
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• 2010

Copper filling into TSV (through-silicon-via) and reduction of the filling time for the three dimensional chip stacking were investigated in this study. A Si wafer with straight vias - $30\;{\mu}m$ in diameter and $60\;{\mu}m$ in depth with $200\;{\mu}m$ pitch - where the vias were drilled by DRIE (Deep Reactive Ion Etching) process, was prepared as a substrate. $SiO_2$, Ti and Au layers were coated as functional layers on the via wall. In order to reduce the time required complete the Cu filling into the TSV, the PPR (periodic pulse reverse) wave current was applied to the cathode of a Si chip during electroplating, and the PR (pulse-reverse) wave current was also applied for a comparison. The experimental results showed 100% filling rate into the TSV in one hour was achieved by the PPR electroplating process. At the interface between the Cu filling and Ti/ Au functional layers, no defect, such as a void, was found. Meanwhile, the electroplating by the PR current showed maximum 43% filling ratio into the TSV in an hour. The applied PPR wave form was confirmed to be effective to fill the TSV in a short time.