Ａｄｖｉｓｅｒ : Ｄａｖｉｄ. Ｔ.W. Ｌｉｎ Reporter : Chi-Hung Tsai 1 Date : 2014/07/01

2 Outline 1. Introduction 2. Motivation and Purpose 3. Experiment 4. Results and Discussions 5. Conclusions

3 Introduction SAW filters Video Communication Touch panel SAW sensors

4 Flexible substrate AdvantageDisadvantage 1. Applies to non-planar occasions. 2. Lightweight and Thin 1. Difficult to manufacture. Rigid substrate AdvantageDisadvantage 1. Wave propagation is stable. 2. Manufacturing process can be done under high temperature. 1. The limitation of usage.

5 Motivation and Purpose 1.To improve the efficiency of wave propagation of the SAW device. 2.To find a robust process for fabricating the flexible SAW devices by spin coating technology and inkjet technology.

6 Bulk acoustic waveSurface acoustic wave Mechanical vibration Piezoelectric effect Mechanical vibration Bulk acoustic wave is vibration of medium internal center into distant by amplitude of the wave. Surface acoustic wave is amplitude of the wave along the surface of the object to propagat.

7 The base structure of SAW device

8 Hexagonal wurtzite structure. N-type semiconductor material. Piezoelectric property on (002) direction. High resistance and high transmittance. Easy dopant to improve the film properties. The Properties of ZnO material

9 PI substrate SubstratePI Length1.5cm Width1.5cm Height0.02mm ZnO film

10 1. Sloution deployment 2. Film deposition 3. Bake 4. Thermal annealing

11 Experiment (3D Print Inkjet)

12 Results and Discussion The parameters of thickness Intensity of (002) direction (a.u.) XRD pattern

13 Results and Discussion

14 Results and Discussion

15 Experiment (Spin Coating) Experiment design Zinc acetate ： Stabilizer 1 ： ： ： ： ： ： ： ： ： ： ： ： 1.5 XRD Taguchi method

11 Orthogonal Arrays L 9 (3 4 )S/N (Signal-to-Noise Ratio) Taguchi Method Exp We used three-level, four control factors and nine orthogonal array experiments. When the ideal value of quality characteristics is based on the film piezoelectric signal, then the signal is getting higher and better. The S / N ratio of Taguchi method is the degree of impact of error on process. Therefore, as a basis for measuring the quality of the experiment. So we used larger-the-Better on the study, S / N ratio is getting higher and better.

FactorsDescriptionLevel 1Level 2Level 3 ASpin coating(RPM)400 RPM800 RPM1600 RPM BHot plate10 minutes20 minutes30 minutes CRatio of Stabilizer DSpin coating(Seconds)10s15s20s

15 Experimental data Results and Discussion Exp.1234T1T2T3T4means/n we used combination of orthogonal arrays to established experimental model. From the experiments combinations, we can get the average and S / N ratio in each group.

16 Response table for S/N Results and Discussion ABCD Level Level Level E E Range Rank1342 Significant?Yesno yes We can not only know the S / N ratio on each control factor levels, but also understand conversion efficiency of S / N ratio on each levels.

17 Response graph for S/N Results and Discussion The figure shows control factors impact S / N ratio of the process, and it can observe the best combination is “A1B2C2D3”.

18 Response table for quality characteristics ABCD Level Level Level E E Range Rank1243 Significant?yes no Results and Discussion We can not only know quality characteristics on each control factor levels, but also understand conversion efficiency of quality characteristics on each levels.

19 Response graph for quality characteristics Results and Discussion The figure shows the results of the best combination is the same as Response graph for S / N is “A1B2C2D3”.

20 CategoryS/N Affected? Quality Characteristics Affected? FactorNote 1yesyes/noA,DReduce variations 2noyesBAdjust y to target. According to the S / N figure and quality characteristics figure. From the table, we can reduce the experimental variability and yield improved by A and D. And then we adjust B to achieve the ideal value on quality characteristics. Results and Discussion

21 Improvement T1T2T3T4Ave. Experime ntal S/N Predicted S/N Original Optimal Results and Discussion Original combination ： 800RPM 、 30min 、 1:1.5 、 15s Optimal combination ： 400RPM 、 20min 、 1:2.0 、 20s Experiments to improve the amount of 1.65 is better than predicted improvement in the amount of 1.44, And the combination is fairly proximity. From the foregoing our orthogonal array of S / N ratio, we can obtain an optimal combination of experimental parameters.

25 1.The crystalline property of ZnO film becomes better as the thickness increases. These results exhibit the obvious intensity at Experiments to improve the amount of 1.65 is better than predicted improvement in the amount of 1.44, And the combination is fairly proximity. Conclusions

26 Thank you for your attention