• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.322-328
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• 2012

This paper deals with a digital Desoldering system for removing lead-free solder. We proposed a Desoldering system that is to cope with the changed work environment of the solder materials changing from lead solder to lead-free solder, we can be quickly stable to the set temperature, and continuous operation is possible. Proposed system consists of a Desoldering station and a Desoldering gun. For the PID temperature control, we designed the 8bit MCU peripheral circuit. We had a few experiments to confirm the performance of the proposed system, and compared with the specification of same kind of imports. As a result, proposed system than the imported products showed good performance as follows: the time to reach operating temperature is 11 seconds faster, ripple temperature variation is $1.5^{\circ}C$ lower, temperature recovery rate is about $0.14^{\circ}C$/sec faster.

• Clean Technology
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• v.12 no.4
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• pp.250-258
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• 2006

CFC compounds such as CFC-113 and 1,1,1-TCE, etc. have been used in various industries due to their excellent chemical stability, thermodynamic characteristics, non-inflammability and anti-corrosiveness. However, in oder to protect the earth environment, "the Montreal Protocol on substances that deplete the ozone layer" was adopted in 1989 for prevention of production and utilization of these CFC compounds and alternative cleaning agent have been required in the industry. The objective of this study is to develop non-aqueous cleaning agents that do not require major change of cleaning system, have excellent cleaning efficiency, are favorable to the environment, are harmless to the human body, and are not generated corrosive materials. In this work, non-aqueous cleaning agents have been formulated with glycol ether series and paraffinic hydrocarbon series with siloxane, and their physical properties and cleaning efficiencies were analyzed and compared with those of regulated materials. As a result of physical properties measurement of the formulated cleaning agents, it is expected that they may have good penetration ability into contaminated materials due to their properties with low density and low surface tension. Measurement of flash point and vapor pressure of the cleaning agents will be helpful for evaluation of their safety and working environment. The experimental results of cleaning flux, solder and grease by the formulated cleaning agents show that their cleaning abilities of soils were good and that there were no residues on the substance after cleaning. Therefore, alternative cleaning agents which have equivalent cleaning ability to regulating materials, good penetration ability and low hazard to human body, have been developed in this work.