聚萘二甲酸乙二醇酯 (PEN)可做為有機發光二極體(Organic Light-Emitting Diode, OLED)封裝元件阻障膜(Barrier Film)之基板材料，而阻障膜可提供阻隔水氣及氧氣之功能，進而提昇OLED之可靠度及使用壽命，然而過大之薄膜應力將導致阻障膜產生不可預期之缺陷，故若能預先量測阻障膜之應力即可確保OLED之品質，而光彈法(Photoelasticity)可對PEN基板進行非破壞性之全場應力量測，但首要之務必須量測PEN基板之應力光學係數(Stress-optic Coefficient, SOC)，才能進行。本研究透過三維光彈法(Three Dimensional Photoelasticity)理論搭配相位移法對PEN之SOC值進行量測，並分析SOC值之非等向性，首度建立出PEN材料之SOC值與特徵角加特徵旋轉角間之系統關係，在建立此關係後，再透過力平衡方程式計算全場之阻障膜應力分佈狀態。為確認以光彈法量測薄膜應力之正確，本研究使用相干梯度感測(Coherent Gradient Sensing, CGS)技術量測PEN基板鍍膜後之薄膜曲率，並對使用CGS技術量測薄膜曲率進行初步探討，預計未來將曲率量測結果代入Stoney方程式中計算薄膜應力。

Polyethylene naphthalate (PEN) has been used as the substrate material of barrier films which are one of encapsulation components of organic light-emitting diode (OLED). The barrier film is used for blocking water vapor and oxygen in OLED. Therefore, the reliability and service life of OLED can be improved by the barrier film. However, unpredictable damages and defects may be caused by the large film stress in the barrier film. If the stress measurement of the barrier film can be appropriately performed in advance, the quality of the OLED can be ensured. Photoelasticity can be used to non-destructively measure the full-field stress distribution of the PEN substrate. However, the stress-optic coefficient (SOC) of the PEN substrate must be obtained beforehand. In this thesis, the theory of three dimensional (3D) photoelasticity and phase-shifting technique were utilized to determine the SOC of the PEN substrate. Furthermore, the anisotropic property of the SOC of the PEN substrate was analyzed. Most importantly, for the first time, the systematic relationship between SOC and the value of characteristic angle as well as characteristic rotation angle of the PEN was constructed. By using this systematic relationship, the full-field stress of the PEN substrate can be obtained. Thus, according to the static equilibrium relationship between the film stress and the substrate stress, the full-field stress of the barrier film can be calculated from the stress of the PEN substrate. In order to ensure the stress measurement results by photoelasticity is correct, the coherent gradient sensing (CGS) technique was used to measure the curvature of the PEN substrate. Initial measurement results of the film curvature by CGS technique was performed. It is expected that the stress of the barrier film can be calculated by substituting the curvature into the Stoney’s equation.

一、 簡介 1
二、 文獻回顧 4
三、 實驗原理 7
3.1 光彈法 7
3.1.1 穿透式光彈法 7
3.1.2 三維光彈法 9
3.2 相位移光彈法 10
四、 實驗試片與架設 15
4.1 實驗試片 15
4.1.1 量測SOC值之拉伸試片 15
4.1.2 薄膜應力量測之試片 16
4.2 實驗架設 17
4.2.1 量測SOC值之架設 17
4.2.2 薄膜應力量測之架設 18
4.3 實驗裝置 18
五、 實驗和分析程序 21
5.1 SOC值量測 21
5.1.1 SOC值量測程序 21
5.1.2 SOC值分析程序 22
5.1.3 β角驗證程序 22
5.2 薄膜應力量測與分析程序 23
六、 結果與討論 26
6.1 PEN基板特徵參數和SOC值之量測 26
6.1.1 第一類拉伸試片特徵參數和SOC值之量測 26
6.1.2 第二類拉伸試片特徵參數和SOC值之量測 29
6.1.3 第三類拉伸試片特徵參數和SOC值之量測 30
6.1.4 三種類別拉伸試片特徵參數量測比較 31
6.1.5 β角驗證結果 31
6.1.6 PEN基板SOC值之驗證 33
6.2 薄膜應力量測 35
七、 結論與未來展望 38
7.1 結論 38
7.2 未來展望 40
八、 參考文獻 42
附錄A: 相干梯度感測之薄膜曲率量測 111
附錄B: 符號表 117

[1] 陳光榮，“軟性OLED阻水氧層技術”， 工業技術研究院顯示中心，材料世界網，2010。
[2] 周宗毅，楊智仁，劉沛瀅，呂奇明，“OLED照明用軟性基板技術”， 工業技術研究院材化所，材料世界網，2011。
[3] 阻障膜缺陷與應力非破壞性檢測之可行性研究，工業技術研究院科技專案學研合作計畫，工業技術研究院電子與光電系統研究所，計畫主持人：王偉中，計畫編號：107A0113JI，執行期限：2017/04/01~2017/11/30
[4] T. Inoue, S. Kuwada, and D. S. Ryu, “Effect of Wavelength on Strain-Induced Birefringence of Polymers,” Polymer Journal, Vol. 30, No. 11, pp. 929-934, 1998.
[5] Y. C. Lee, T. S. Liu, C. I. Wu, and W. Y. Lin, “Investigation on Residual Stress and Stress-Optical Coefficient for Flexible Electronics by Photoelasticity,” Measurement, Vol. 45, pp. 311-316, 2012.
[6] K. Ramesh, “Digital Photoelasticity: Advanced Techniques and Applications,” Springer-Verlag, Berlin, Germany, 2000.
[7] R. D. Mindlin, “A Review of the Photoelastic Method of Stress Analysis I,” Journal of Applied Physics, Vol. 10, pp. 222-241, 1939.
[8] J. C. Maxwell, “On the Equilibrium of Elastic Solids,” Transactions of the Royal Society of Edinburgh, Vol. 20, pp. 87-120, 1853.
[9] E. G. Coker and L. N. G. Filon, “A Treatise on Photoelasticity,” Cambridge University Press, Cambridge, U. K., 1931.
[10] J. W. Dally and W. F. Riley, “Experimental Stress Analysis,” 3rd ed., McGraw-Hill, New York, U. S. A., 1991.
[11] H. Aben, “Integrated Photoelasticity,” Springer, Berlin, Heidelberg, 1993.
[12] F. W. Hecker and B. Morche, “Computer-Aided Measurement of Relative Retardations in Plane Photoelasticity,” Proceedings of the VIIIth International Conference on Experimental Stress Analysis, Amsterdam, The Netherlands, pp. 535-542, 1986.
[13] G. M. Brown and J. L. Sullivan, “The Computer-Aided Holophotoelastic Method,” Experimental Mechanics, Vol. 30, pp. 135-144, 1990.
[14] S. K. Mangal and K. Ramesh, “Determination of Characteristic Parameters in Integrated Photoelasticity by Phase-Shifting Technique,” Optics and Lasers in Engineering, Vol. 31, pp. 263-278, 1999.
[15] R. A. Tomlinson and E .A. Patterson, “The Use of Phase-Stepping for the Measurement of Characteristic Parameters in Integrated Photoelasticity,” Experimental Mechanics, Vol. 42, 2002.
[16] F. W. Hecker, “On Phase-Shifting Integrated Photoelasticity,” Strain, Vol. 43, pp. 219-228, 2007.
[17] H. Shafiee and S. Beppu, “Mechanisms of Orientational and Photoelastic Birefringence Generation of Methacrylates for the Design of Zero-Zero-Birefringence Polymers,” Polymer Engineering and Science, Vol. 55, pp. 1330-1338, 2015.
[18] G. G. Stoney, “The Tension of Metallic Films Deposited by Electrolysis,” Proceedings of the Royal Society of London, vol. 82, pp. 172-175, 1909.
[19] G. C. A. M. Janssen, M. M. Abdalla, F. V. Keulen, B. R. Pujada, and B. V. Venrooy, “Celebrating the 100th Anniversary of the Stoney Equation for Film Stress: Developments from Polycrystalline Steel Strips to Single Crystal Silicon Wafers,” Thin Solid Films, vol. 517, pp. 1858-1867, 2009.
[20] P. Y. Chen, W. C. Wang, and Y. T. Wu, “Experimental Investigation of Thin Film Stress by Stoney’s Formula,” Measurement, Vol. 143, pp. 39-50, 2019.
[21] Website : http://compass.astm.org/Standards/HISTORICAL/D882-09.htm
[22] Website : http://www.sharplesstress.com/
[23] Website : http://www.optimax.com.tw/polarizer/chinese/index.html
[24] Website : http://diffractionlimited.com/
[25] Website : http://www.hungta.com/tw/about.html
[26] MATLAB Help Handbook, The Matheorks, Inc
[27] Website : http:// http://www.futek.com/index.aspx
[28] Website : https://www.aone.com.tw/KAPTON_Tape_c.htm