• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.28-35
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• 2010

In the display industry, COG bonding method is being applied to production of LCD panels that are used for mobile phones and monitors, and is one of the mounting methods optimized to compete with the trend of ultra small, ultra thin and low cost of display. In COG bonding process, electrical characteristics such as contact resistance, insulation property, etc and mechanical characteristics such as bonding strength, etc depend on properties of conductive particles and epoxy resin along with ACF materials used for COG by manufacturers. As the properties of such materials have close relation to optimization of bonding conditions such as temperature, pressure, time, etc in COG bonding process, it is requested to carry out an in-depth study on characteristics of COG bonding, based on which development of bonding process equipment shall be processed. In this study were analyzed the characteristics of COG bonding process, performed the analysis and reliability evaluation on electrical and mechanical characteristics of COG bonding using ACF to find optimum bonding conditions for ACF, and performed the experiment on bonding characteristics regarding fine pitch to understand the affection on finer pitch in COG bonding. It was found that it is difficult to find optimum conditions because it is more difficult to perform alignment as the pitch becomes finer, but only if alignment has been made, it becomes similar to optimum conditions in general COG bonding regardless of pitch intervals.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1053-1054
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• 2009

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.21-27
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• 2010

The effect of COG bonding parameters, especially the bonding temperature, on the bonding quality and reliability was investigated in this paper. We measured the bubble area formed in the ACF resin during the bonding process and tried to investigate the relationship between bubble area and bonding peel strength. 85/85 test which exposes a sample to a 85% humidity and $85^{\circ}C$ temperature condition was also carried out. The bubble area was dramatically increased under ~$10^{\circ}C$ lower than recommended bonding temperature. The bubble area formed at the edge of IC chip was larger than the other parts of IC chip. But the peel strength was not associated with the bubble area. High temperature and humid condition made the bubble area larger, but we could not find clear trend of change in the peel strength.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.7-12
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• 2010

In this paper, chip-on-glass(COG) interconnection with anisotropic conductive film(ACF) using lateral thermosonic bonding technology is considered. In general, thermo-compression bonding which is used in practice for flip-chip bonding suffers from the low productivity due to the long bonding time. It will be shown that the bonding time can be improved by using lateral thermosonic bonding in which lateral ultrasonic vibration together with thermo-compression is utilized. By measuring the internal temperature of ACF, the fast curing of ACF thanks to lateral ultrasonic vibration will be verified. Moreover, to prove the reliability of the lateral thermosonic bonding, observation of pressured mark by conductive particles, shear test, and water absorption test will be conducted.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.11a
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• pp.53-81
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• 2006

A COG(Chip on Glass) bonding process that is one of display packaging technology and bonds between driver IC chip and a glass panel using ACF(Anisotropic Conductive Film)has been investigated by using diode laser. This method is possible to raise cure temperature of ACF within one second and can reduce the total process time for COG bonding by a conventional method such as a hot plate. Also we can get good pressure mark on the surface of electrodes and higher bonding strength than that by convention method. Results show that laser COG bonding can give low pressure bonding and decrease a warpage of panel. We believe that it can be applied to fine pitch module.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.613-614
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.615-616
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• 2010

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.11a
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• pp.66-66
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• 2004

• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.11a
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• pp.85-89
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.923-924
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• 2009