• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4736-4741
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• 2014

This study examined PCB component cleaning on a PCB component surface, which has defects of precipitation type washing (existing rinse method), sealant and foreign material formed in the adhesive process that could not be removed easily. The spin jig was developed for PCB component cleaning, in which the PCB component settled down, to solve the conventional problem of the removal of foreign material with the centrifugal force by high speed rotation. The results are as follows. With decreasing fraction defect in PCB component washing, the development and substrate damage decreased by more than 80% according to the abstergent in the rotary type using the centrifugal force in the existing precipitation type. When the base plate showed a large difference with the time to include the process after washing the design using the existing method, easy attachment and separation of the PCB component could be possible. The washing time was enhanced 90% compared to the existing time. The reliability of the security and washing collaboration of the design and stability of the cleaning process could be secured so that there was no phenomenon of secession, the PCB component fixed for a cleansing rotation jig could maintain a fixed force by the centrifugal force. The stability and reliability of the washing process and the defective rate could be improved to less than 1%.

• Clean Technology
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• v.18 no.3
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• pp.287-294
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• 2012

In this study, performances of two cleaning methods were analyzed and a cleaning system was designed to develop a cleaning process of electronic components to remanufacture old laser copy machine. First, plasma cleaning as a dry cleaning method was executed to test cleaning ability. In cleaning of printed circuit board (PCB) by plasma, some damages were found near the metal parts, and considering the productivity, this method was not adequate for the cleaning of electronic components. With 4 different cleaning agents, ultrasonic cleaning tests were executed to select an optimal cleaning agent, aqueous agents showed superior cleaning performance compared to semi-aqueous and non-aqueous agents. Cleaning with aqueous cleaning agent A and 28 kHz ultrasonic frequency can be completed in 30 sec to 1 min. Finally, an ultrasonic cleaning system was constructed based on the pre-test results. Optimal cleaning conditions of 40 kHz and $50^{\circ}C$ were found in the field test. The productivity and economic efficiency in remanufacturing of laser copy machine are expected to increase by adapting developed ultrasonic cleaning system.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.688-694
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• 2009

A spray-type cleaning agent in utilizing dust-remover on PCB was chosen to study the cleanliness test and efficiency. In order to choose alternative environmental-friendly cleaning agents, it is important that the systematic selection procedures should be introduced and applied through the evaluation of their cleaning ability, environmental characteristics, and economical factors, and that the objective and effective evaluation methods of cleanliness should be established for the industry. A novel cleaning evaluation method with scanning electron microscopy/energy-dispersive X-ray analysis of surface observation evaluation method and an infra-red thermography camera(THERMOVISION A20 model) was studied in this work. The sound card(CT-2770 model) cut by $2{\times}2cm$ size was used as a part, and before and after the spray cleaning, the cleanliness was observed by the image analyzer of SEM and further the removal efficiency of dust was quantitatively evaluated by the component analysis of EDX. For the parts of P4TE model motherboard and IPC-A-36 PCB plate, before and after the spray cleaning, temperature differences were measured and compared at room temperature and 50 oven temperature by an infra-red thermography camera in the contaminants of dust and iron powder.

• Clean Technology
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• v.17 no.4
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• pp.306-313
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• 2011

Flux or solder is used in soldering process for manufacturing electronic parts such as printed circuit boards (PCB). After soldering process, residual flux and solder paste on the parts should be removed since their residuals could cause performance degradation or failure of parts due to their corrosion and electric leakage. Ozone depletion substances such as 1,1,1- trichloroethane (TCE) and HCFC-141b have widely been using for removal of residual flux and solder paste after soldering process In manufacturing of electronic parts until now. In this study, non-aqueous cleaning agents without flash point were developed and applied to industrial field for replacement of cleaning agents with ozone depletion. In order to develop non-aqueous cleaning agents without ethers, esters, fluoride- type solvents. And their physical properties and cleaning abilities were evaluated, and they were applied to industrial fields for cleaning of flux and solder on the PCB. And vacuum distillation apparatus were operated to determine their operating conditions and recycling yields for recycling of used cleaning agents formulated in this study. As a result of physical properties measurement of our formulated cleaning agents, they were expected to have good wetting and penetrating power since their surface tensions were relatively low as 18.0~20.4 dyne/$cm^2$ and their wetting indices are relatively large. And some cleaning agents holding fluoride-type solvents as their components did not have any flash point and they seemed to be safe in their handling and storage. The cleaning experimental results showed that some cleaning agents were better in their cleaning of flux and solder paste than 1,1,1-TCE and HCFC-141b. And industrial application results of the formulated cleaning agents for cleaning PCB indicated that they can be applicable to industry due to their good cleaning capability in comparison with HCFC-141b. The recycling experiments of the used formulated cleaning agents through a vacuum distillation apparatus also showed that their 91.9~97.5% could be recycled with its proper operating conditions.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.401-404
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• 2010

A spray-type cleaning agent in utilizing dust-remover on PCB was chosen to study. In cleaning of electronic and semiconductor equipment, a substrate(IPC-A-36) was used to test the jet forces of the agent. And according to the jet forces time of the cleaning agent, the corresponding moving distances were compared with the spray times, and for the pollutants of iron powder and dust, the cleaning efficiency was tested with the IPC-A-36 by a weight method. The moving distance increased with the spray cleaning time longer. For a spray cleaning time of 3sec, the cleaning efficiency decreased with the amount of dust and the iron powder. It was also observed that the dust was remarkably removed, compared to the iron powder.

• Analytical Science and Technology
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• v.6 no.1
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• pp.65-75
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• 1993

A number of alternative cleaning solvents to CFC 113 which was identified as a ozone-depleting meterial were collected to measure their experimental physecal properties of density, surface tension, Refractive Index, boiling point, pH, viscosity, flash point, and soltbility. They might be classified as aqueous, simi-aqeous, alcohol ketone, and halogen cleaning solvents. The solubilities of abietic acid, a major component of flux used in PCB (Printed Circuit Board) of the electronic indystry, into the cleaning solvents including CFC 113 were determined for comparison. The assorted cleaning solvents have their own advantages and disadvantages. Therefore a end-user carefully needs to choose the best-fit cleaning solvent after the safety, stability, and economics as well as the effectiveness by physical properties of the alternative cleaning solvents are integratedly considered.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.8-13
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• 2016

The micro drill bit automatic regrinding in-line system is a system that refurbishes drill bits used in a PCB manufacturing process. This system is able to refurbish drill bits with a minimum size of ø0.15-0.075mm that have previously been discarded. Beyond the conventional manual cleaning process using ultrasound, this system adopts a water jet cleaning system, making it capable of cleaning drill bits with a minimum size of ø0.15-0.075mm. This paper analyses various contact pressures applied to the surface of drill bits depending on the shooting pressure of the cleaning device and fluid velocity in order to optimize the nozzle location and to detect structural instability caused by the contact pressures.

• Korean Journal of Computational Design and Engineering
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• v.20 no.3
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• pp.291-297
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• 2015

A water jet cleaning robot system for micro drill bits is to refurbish micro drill bits used for the PCB manufacturing process. It can refurbish drill bits with the minimum diameter of ${\phi}0.15{\sim}0.075mm$ of which the total quantity have been discarded before. Micro drill bits with the minimum diameter of ${\phi}0.075mm$ can be cleaned by applying the water jet cleaning robot system out of the manual ultrasonic cleaning in the past for the cleaning equipment as the initial process in refurbishing. This study analyzed problems, while applying the apparatus mechanism for the workability such as the robot traces of Transfer Robot I and II, drill bit loading and unloading, and cleaning tasks in the water jet cleaning robot system in an effort to carry out simulations. In addition, the cleaning work process was optimized as the work process was verified in advance and the production quantity was analyzed through simulations.

• Analytical Science and Technology
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• v.6 no.5
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• pp.521-530
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• 1993

According to the Montreal Protocol, CFC 113, one of the ozone-depleting substances, will be prohibited to use as a cleaning solvent essentially in the electronic industry. Therefore, the development of the alternative cleaning solvents to CFC 113 is being accelerated. A number of the alternative cleaning solvents are avialable on the market. The alternatives of Axarel 32(DuPont), Cleanthru 750H(KAO Chemical), and EC-Ultra(Petroferm) are chosen for the comparison of cleaning performance with CFC 113. The test methods for measuring the cleaning performance were composed of the measurement of the physical properties, the experiments on the material compatibility with cleaning solvents, the measurement of the evaporation rate, and finally the experiments of the removal efficiency. Normally the basic physical properties of the alternatives had higher boiling points, viscosity and surface tension, which were quite different to those of CFC 113. In terms of solubility of rosin-based flux, the solubilities of abietic acid (nonpolar organic) were similar, but those of the activator (polar organic) in the alternatives were better than CFC 113. The evaporation of the alternatives was very slow, compared to CFC 113, which had much lower boiling point. All the cleaning solvents showed the good material compatibility with FR4 and Cu-coated PCB. The better removal efficiencies of abietic acid were obtained when using the ultrasonic mechanical energy over the dipping method. The experiments also indicated the very slow-eavaporating solvent was not desirable with the dipping cleaning method, and the differences in the removal efficiency of the alternatives with the ultrasonic cleaning method were negligible. Among the alternatives, the overall cleaning performances were obsorved as almost similar. Before selecting the ultimate cleaning solvent, the application of cleaning machine, environmental issues, and economics are simultaneously considered with the cleaning performance.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.3
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• pp.53-59
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• 2009

Low pressure mercury lamp type UV equipments have been widely used for cleaning and modification of PCB surfaces. To enhance the productivity of the process, we newly developed remote DBD type atmospheric pressure plasma equipment. The productivity of both equipments could be compared by measuring surface contact angle for various transferring speed. By the result of the measurement, we could verify that the productivity of the atmospheric pressure plasma be superior to the productivity of the UV equipment. XPS experiments confirmed that the surface effect of the UV and atmospheric pressure plasma processing are similar for each other. Organic contamination level was reduced after the processing and some surface elements were oxidized for both cases. Finally, the atmospheric pressure plasma equipment was adapted to flip chip BGA's flux printing process and it was concluded that the printing uniformity be enhanced by the atmospheric pressure plasma surface treatment.