自調式刮刀塗佈機之設備改良解決大面積軟性高分子發光二極體照明之製程問題

Self-adjusting blade coating facility improvements to solve large-area flexible polymer light-emitting diode lighting of process issues

吳宥翰(YOU-HAN WU)

指導教授 ： 鄭榮偉

國立中正大學/工學院/機械工程學系/碩士(2016年)

摘要

本文致力於大面積軟性電子塗佈製程之研發。將現有自調式刮刀塗佈設備應用於大面積軟性高分子發光二極體照明元件的製程中。論文中特別針對塗佈製程中所觀察到的薄膜暗紋、溶液回流以及濕膜揮發不均等問題進行探討且提出有效的製程與設備改良方法。
濕膜揮發不均乃是因咖啡圈現象導致溶液內部產生毛細流，此毛細流夾帶著溶質往濕膜邊緣積累，導致濕膜完全揮發後之薄膜厚度非常不均勻，為此我們使用紅外線燈管對濕膜進行加熱加速其揮發速度，有效的抑制咖啡圈現象對膜後均勻度的影響。
在薄膜暗紋的部分，其成因係因為當刮刀表面不平整時，所塗佈之濕膜的膜厚將不同，在紅外線燈管加熱快速烘乾下，在運動方向呈現條紋狀的暗紋；為此我們將刮刀更換為刀鋒平整的光學玻璃刮刀，解決了此暗紋問題，並且單層塗佈導電高分子poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)在40  225 mm範圍內，達到平均膜厚為27.7 nm，標準差僅1.63 nm，膜厚變異百分比5.9%的高品質薄膜。
溶液回流乃是因液體在觸碰到刮刀遭毛細力拉至刮刀兩側時，因表面張力限制而無法流出刮刀兩側，並同時受到後繼而來的液體推擠，導致液體往刮刀另一側回流。而在塗佈PEDOT:PSS因其黏滯係數約為40 cP，溶液流動力較低回流現象較不明顯，而塗佈半導體高分子poly(3-hexylthiophene-2,5-diyl) (P3HT)時因其黏滯係數約為1 cP，溶液流動力高，回流現象非常嚴重。為此我們設計一導流系統將流至刮刀兩側之液體引流至刮刀兩側以外以解決此回流現象，也在刮刀上加裝導流系統單層塗佈P3HT在50  250 mm範圍內，達到平均膜厚為18.1 nm，標準差僅0.97 nm，膜厚變異百分比5.35%的高品質薄膜。
最後使用此經改良之設備雙層塗佈電洞傳輸層(PEDOT:PSS)以及發光層(Poly[9,9-dioctylfluorenyl-2,7-diyl]-End capped with N,N-Bis(4-methylphenyl)-aniline)，成功製作面積為 60  250 mm的軟性高分子發光二極體照明元件。

關鍵字

溶液回流 ； 濕膜揮發不均 ； 薄膜暗紋 ； 溶液印刷製程問題 ； 自調式刮刀塗佈

並列摘要

This paper is devoted to development of process of large-area flexible electronics. Use the equipment of self-adjusting blade coater on the process of large-area flexible polymer light-emitting diode lighting device. Proposed the solutions of problem of solution coating process like film dark line、solution refluxed and the not uniform’s volatile of wet film.
The cause of the not uniform’s volatile of wet film is coffee ring effect, for this we accelerate the evaporation rate of wet film with install an infrared ray lamp, it effectively inhibits the effect of coffee ring and solved the problem of uneven volatile of wet film.
The cause of the dark line of wet film is not smooth of blade surface, the wet film surface was not smooth when it through under the blade, and the IR lamp was accelerated the evaporation rate of wet film, lead the not smooth wet film doesn’t have enough time to flatten by surface tension, the wet film was presented on the PLED device by dark line when solvent was completely volatilized, for this we selected the smooth’s material and change blade from metal cylinder to optical glass to solved the problem of film dark line, and we got the film thickness was 27.7  1.63 nm and variance was 5.9 % at 40  225 mm by coated HTL Solar.
About the solution refluxed we designed a direct fluid system with blade and substrate, used this direct fluid system we got the excellent coated performance by coated P3HT, the film thickness was 18.1  097 nm and variance was 5.35 % at 50  250 mm.
Used the improved self-adjusting blade equipment manufacture the large-area flexible PLED lighting device by coated hole transform layer (PEDOT:PSS) and emitting layer (PFO) its area was 60  250 mm.

並列關鍵字

uneven volatile of wet film ； solution refluxed ； the problem of solution coated process ； self-adjusting blade coater ； dark line of wet film

參考文獻

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