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Yamagata University New Technology Presentation Meeting (November 30th)


Yamagata University New Technology Presentation Meeting
Functional materials are selectively deposited on the electrode by laser coating method in liquid

November 30th, Yamagata University New Technology Presentation Meetings was held by online method. In this here, oral presentation of Akihiro Nishiyama associate professor about laser micro coating technology is picked up.

The research group developed a new laser coating process in liquid, which is a direct patterning process selectively using laser. Concretely, a functional colloid grain is dispersed into general liquid, such as water, ethanol, and so on. The next, laser beam is irradiated with electrode of the substrate in this dilute liquid. As a result, air bubble occurs on the electrode, and then, colloid grain is selectively sucked into the electrode and becomes solidified adhesively.


Pic.1 SEM image of electrode
In short, it's not thermal reaction process, but light reaction process by laser beam. For this reason, its mechanism is different from that of the conventional thermal laser process. Therefore, it's thermal damage-free. After process, colloid grain becomes solidified on the electrode at solid state. In short, it's not melted. After process, initial property of colloid grain keeps.

As lecture title, alternative of material is wide. Concretely, SiO2, TiO2, ZnO, ITO, PZT, Li series, and ZnO+Au, in short, insulation material, semiconductor material, and emitting material can be used in this process inclusive of inorganic and organic materials. Of course, it's vacuum-free. And also, it's possible to correspond to curved plane and flexible substrate.


Fig.1 Relationship of line width and laser power
Picture 1 shows SEM image of Ag electrode with deposited SiO2 by this process. After process, line width changed from 2.5 μm to 5 μm. Grain diameter and thickness of SiO2 were 20 nm and 1.1 μm respectively.

Figure 1 shows relationship of line width and laser power. It's possible to control line width by laser power. By the way, practice throughput same as 1 m/sec will be obtained by divaricating of laser beam and parallel treatment.

As regards product, stand-alone system and added value unit can be released, too. In the latter, if this unit is built in the ink jet (IJ) printing system, functional films can be deposited on IJ printed ink film selectively.

REMARK
STELLA NEWS SITE is a free news site of FPD and PCB by Stella Corporation Inc.(This company does not release these FPD and PCB related products.)

Stella's repair system“Repair Vision” is suitable for repair use of electrode and so on. Also, it's possible to directly pattern ITO, metal, CNT (Carbon Nano Tube) films by use of this system, too.