Formation of thermoeletric material film using precision screen-printing technology

[[abstract]]In nowadays, electronic components are tended to have high density and high work-frequency, and property of high temperature appears. Therefore, cooling of components is an important consideration. Micro-thermoelectric cooler is suit to application of industry and has advantages as followed: small volume, no pollution, and exact temperature control etc. At present, thermoelectric cooler are fabricated by complicated traditional technologies such as Bridgman method, hot pressing method, or micro fabrication such as sputter, hot evaporation, or MOCVD (metal-organic chemical vapor deposition). Screen-printing technology can fabricate micro thermoelectric components with simple process, lower cost and less fabrication hours, and can be popularized in industry. This research has three points as followed: (1) Estimation of DPI (dots per inch) and quality of structure formation by screen-printing technology. (2) To fabricate thermoelectric film on silicon substrate by screen-printing technology, and to estimate morphology, composition, and thermoelectric characteristic. (3) To experiment and discuss process of thermoelectric component fabricated by screen-printing technology. In the research, we use UV sensitive ink (GN-52-479) with viscosity of 50 Pa?s to test the best range of width. The results show that the smallest width of pattern is 40 ?m, and pattern with 50-100 ?m width has better screen-printing quality. Besides, we mix 1:4 by weight of binder and thermoelectric powder to be thermoelectric ink and print 18×18 mm2 thermoelectric film. After 4 hours sintering of Bi2Te3 (560 ?C) and Sb2Te3 (585 ?C), Seeback coefficient and resistivity of Bi2Te3 are -57.06 ?V/K and 4.40×10-5 ?m, and values of Sb2Te3 are 64.70 ?V/K and 7.33×10-5 ?m. Using the technology to print thermoelectric structure three times can get thickness more than 20 ?m with widths of 75 ?m and 100 ?m.