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Research paper : Development of laser-assisted inkjet printing technology (A. Endo et al.)−18−Synthesiology - English edition Vol.4 No.1 (2011) Discussions with Reviewers1 Overall commentComment (Yasuo Hasegawa, Energy Technology Research Institute, AIST)I think the developed technology is excellent, but to make this paper suitable for Synthesiology, please revise the following two points.2 Clear statement of the technological issuesComment (Yasuo Hasegawa)For the titles of the subchapters, please revise them so the technological issues to be overcome can be readily seen.Answer (Akito Endo)In response to your comment, I revised the text so that the summary of the subchapters became the titles of the subchapters.3 Solution to the ejecting frequencyComment (Yasuo Hasegawa)You indicate the issue of ejecting frequency, but can you describe how, after all, the authors solved the issue?Answer (Akito Endo)Until now, to reduce the width and the resistance of the formed wire, we reduced the size of the discharged droplet and reduced the ink supply per unit length, or in other words, we tried to increase the ejecting frequency of the inkjet. However, since we could increase the ink supply per unit length by forming the wire with small width using large droplets, we were able to solve the problem without greatly increasing the ejecting frequency.4 Comparison with the conventional approachesComment (Yasuo Hasegawa)For the conventional approaches compared with this research, please explain logically why those approaches were not appropriate, what kind of breakthroughs were necessary, and how you solved the problems. I think it will be easier to understand if you itemize the problems of high viscosity ink.Answer (Akito Endo)The following four methods are efforts to even out the wiring pattern and to reduce the wire resistance:(1) Decrease resistivity of ink limit of low resistivity(2) Discharge high viscosity ink and reduce size of droplet nozzle clogging and limit of ejecting frequency(3) Formation of even pattern through surface treatment reduced throughput by making the process complicated(4) Increase drying speed by heating breaks in wire due to bumping caused by rapid drying1 and 2 greatly affect the narrowing of the wire width, and 3 and 4 the formation of even patterns. There were issues that were difficult to solve in using the inkjet as a practical process technology.These four methods were not ways to deal with the essential issues of drying droplets in the process where the droplet discharged by the inkjet wet-spread at the moment it landed and dried. From the viewpoint of improving throughput, we set our topic as the control of wet-spreading of the droplet. As a result, we used the idea of locally applying the heat energy necessary for drying to the ink droplet by laser irradiation. This enabled the formation of wire with high aspect ratio with width smaller than the droplet diameter, without greatly increasing the ejecting frequency and with large droplet diameter, by optimizing the drying speed.5 Size of droplet and value of the wire widthComment (Yasuo Hasegawa)Please indicate what were the droplet size and wire width in the conventional inkjet method. Since this is related to the development goal set in this research, please state them clearly.Answer (Akito Endo)The droplet size used in the conventional industrial inkjet method was about 15 m (1.8 pl) ~ 40 m (33.5 pl) in diameter. Therefore, the wire width was about 30 m ~ 50 m since it became larger than the droplet size, and the thickness was thought to be limited to several tens nm to several hundreds nm. When recoating was done several times to thicken the wire to about several m, bulges occurred and formation of even wires was difficult.6 Reason for setting the droplet sizeComment (Yasuo Hasegawa)Please state clearly the logic of setting the droplet size. Did you decide on the droplet size after setting the target thickness from the target wire width and the target resistivity when it was formed?Answer (Akito Endo)In the conventional inkjet technology, the discharge of droplets of 10 m or less was difficult. Therefore, the target values we set were wire width 10 m or less and forming speed of several mm/sec to several tens mm/sec per nozzle. As technological issue needed to achieve the goal, it was necessary to form the wire width smaller than the droplet diameter. Therefore, we set the droplet diameter at 10 m or more.microfabrication, and fiber optic measurement. Currently studying the ceramics integration technology by aerosol deposition method and MEMS device. Project leader of NEDO Nano Level Electronic Ceramics Material Low Temperature Formation and Integration Technology for 5 years since 2002. Works on NEDO “Development of High-Integration Complex MEMS Manufacturing Technology” from 2007. Devised the laser-assisted inkjet technology in the “MEMS-Semiconductor Lateral Wiring Technology” and was in charge of the integration of the theme.

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