• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.2
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• pp.1-12
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• 2012

In this experiment, we have manufactured thermal-curable silver pastes for direct printing. And to enhance conductivity, printability, adhesion and hardness during polymer direct-gravure prints, we have manufactured Ag pastes by adding variety of filter contents. Then we have investigated characteristics of rheology in paste according to the gravure printability and the properties of printed conductive patterns. Depending on a variety of Ag powder, there was a big difference in sharpness of printed pattern. And also by the use of carbon, there was a big difference in amount of solvent used, conductivity and in hardness. We could improve doctoring and the sharpness of a pattern by adding Ag paste in carbon particle, but as we have used nano-sized particle, there was an increase in the amount of solvent used and also we have found out that it gives a bad effect as adhesive and hardness becomes weaker. Even though Ag particle has the same spherical shape, the surface treatments could differ from one another. And by the appropriate choice and with the suitable combination of Ag powder, excellent printability and conductivity could be obtained.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.169-172
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• 2002

Silver pastes for inner conductor in the Low Temperature Co-fired Ceramics (LTCC) are composed of silver powder, binder, solvent and additives. The composition of the chemicals have influence on rheology, printability, shrinkage rate, etc. In this study, commercial Ag pastes and Ag pastes made in KETI were investigated to find the relationship between characteristics of Ag paste and solid contents. Ag pastes with 68~90 wt% Solid Contents were tested. Substrate/paste matching property and conductivity of the conductor lines showed large dependence on solid contents of Ag paste.

• Journal of the Korean Graphic Arts Communication Society
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• v.28 no.1
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• pp.15-24
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• 2010

Photovoltaic solar cells are all in the incident because they are not converted into electrical energy, high-efficiency solar cells in order to reduce the loss of elements must be. Significant factor in the loss of solar cells, optical loss and electrical loss can be divided into. Optical losses occur when the sun will be joined on the surface of the reflection, the shadow loss due to electrodes, and the losses are in the solar wavelengths. Commercialization is currently the most common solar cells on the front of the light incident on the electrode is formed. Therefore, the shadow caused by the electrode to cover the dead area of the sun, due to factors that hinder the absorption of sunlight which is shadowing them and conversion efficiency of solar cells is the inhibition factor. These barriers to eliminate the electrode linewidth reduces the shadowing to reduce, but simply of the electrode line width is reduced electrode area by reducing the series resistance elevates this because to improve the electrode Aspect ratio(height/width) to increase Ag development of paste is required. In this study, aspect ratio of screen-printing method to increase the electrode Ag paste composition of the binder for the characterization of rheology in the shadow of the electrode by reducing the optical loss of the photoelectric conversion efficiency of solar cells to boost the performance measures was. Properties and printability of the paste, the binder resin sintered characteristics that affect the thermal properties are excellent with a good screen printability acrylic resin, ethyl cellulose, using a resin were evaluated. Prepared paste rheology properties, was formed to evaluate the electrode conductivity and aspect ratio.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.957-958
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.721-722
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• 2008

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.111-111
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• 2000

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.2
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• pp.59-68
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• 2012

As one of the eletronic device industries has been developed by using a recent printing method, the consumption of Ag paste has been on the rise as well. The printing method has simple processes in comparison with other methods. Also it enables to be large-scaled and to lower price ranges. If UV curing system would be applied to the printing method, energy consumption and dangerousness from curing system can be minimized in a short period of time so that its method can be more eco-friendly. This study conducted an experiment in order to make UV curing Ag paste which is feasible to implement micro patterns with different dispersing agents. The purpose of the study is to analysis the suitable printability for micro pattern and to test dispersibility, hardening properties, conductivity and adhesive stength by measuring viscosity, TI(thixotropy index), G', G", $tan{\delta}$(G"/G') after making paste. We have experimented with four dispersing agents. After We did an analysis of characteristic of rheology, conductivity and adhesive stength, etc, We confirmed that the paste added FP 3060 has excellent dispersibility, conductivity and adhesive stength. If the paste has excellent dispersibility, we will expect that micro pattern is made by that.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.546-546
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• 2012

Traditional screen printing is still a dominant method to print electrodes on c-Si solar cells. In order to achieve higher efficiency for c-Si solar cells, improvement of the electrode material is one of the key approaches. Shadowing loss can be reduced by using high aspect ratio finger electrode with width of finger electrode less than 80um. The rheological properties of Ag paste for applying c-Si solar cells are improved by using Ag nanowires. The printing properties including the aspect ratio of printed electrode can be improved with higher Thixotropic index (T.I.) values.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.2
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• pp.85-90
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• 2014

Ag paste has been used in the front electrode of the Si-solar cell. It is composed by Ag powder, glass frit, binder, solvent and dispersant. The role of the binder and the solvent is to make a flow and a printing property. However, it was not enough to report the printing properties with the variation of binder in the controled viscosity. In this study, we selected 3 kinds of typical binder which were used as binder for the paste in the industry, such as Ethyl cellulose, Hydroxypropyl cellulose and Acrylic. Ag pastes using these were prepared, controled viscosity and printed on the SiNx coated Si wafer. In the 'A paste' used Acrylic binder, printed hight was highest and 'H paste' used Hydroxypropyl cellulose binder was lowest. Because 'H paste' was high viscosity due to the molecular weight, the solvent was added in the paste to control the viscosity. Therefore, the content of solid was lower in 'H paste'. The relative pattern width which is related to the spreading of paste was the best in the case of 'H paste' and 'EH paste' at $30^{\circ}C$. It is thought that the optimization of the relative pattern width is possible for a paste by the controling shear thinning phenomenon. In the case of 'A paste', though printing hight was best, the pattern width was dependant on the temperature.

• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.1
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• pp.39-50
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• 2008

We have manufactured Ag pastes for gravure printing by adding different solvent contents. Then the gravure printability and properties of conductive patterns gravure-printed by the different rheology characteristics of pastes were investigated. The dispersity of pastes was increased and the viscosity and shear rate dependence of viscosity for pastes were decreased by increasing the solvent content. Also storage modulus G', loss modulus G" and angular frequency value when G" starts to be bigger than G' of pastes were increased by decreasing the solvent content. These mean a flow drop of paste. As a result of gravure printing using two plates which have different line counts(175line and 350line), conductive patterns printed using 175line were spreaded more but Ag packing, thickness and conductivity of the conductive patterns were better than those printed using 350line. And the spread values of conductive patterns were increased with solvent contents but the best properties for Ag packing, surface roughness and conductivity of the conductive pattern were obtained by paste (3) which has 550cps of viscosity at $100s^{-1}$ and tan ${\delta}$ > 1 at 10rad/s. As a result of gravure printing using 350 line plate and paste (3), the conductive pattern has $1.2{\mu}m$ of film thickness and $1.9{\times}10^{-5}{\Omega}{\cdot}cm$ of conductivity.