本文將介紹一應用於壓阻式壓力感測器之新型晶片等級封裝方式（wafer level package, WLP），主要是利用高分子矽膠材料聚二甲基矽氧烷（polydimethylsiloxane, PDMS），取代傳統的Pyrex #7740玻璃作為壓力感測器中，壓力薄膜下方空腔結構（pressure cavity）的密封材。使用聚二甲基矽氧烷作為封裝材料有許多優點，第一，聚二甲基矽氧烷表面經過氧氣電漿處理後，其親水性的表面與許多微機電製程材料，如矽、氧化矽、氮化矽等都有非常良好的鍵合效果，且其封裝過程皆為室溫製程。第二，其本身成本比其它矽質材料便宜許多。第三，其封裝製程時間僅需半小時，比起其它傳統封裝製程要來的快速。本文利用此新封裝材料與製程，製作PDMS新型封裝之壓阻式微型壓力感測器，300psi下之壓力測試結果初步驗證了輸出靈敏度與氣密性之要求。

This paper describes a novel wafer-level packaging method at room temperature for piezoresistive pressure sensors. We use polydimethylsiloxane (PDMS) to seal the wafer backside with V-grooves for pressure sensors. PDMS has several advantages in packaging herein. First, it can be bonded with many kinds of the materials (e.g., single-crystal silicon, silicon dioxide, silicon nitride, glass and another PDMS) after the hydrophilic surface treatment at room temperature. Second, it is much cheaper compared to other silicon-based materials (e.g., PDMS costs only US$100 per 1 kg for 50 times of usage on a 4 inch wafers at least). Third, the processing time is only half of hour and much shorter than other bonding processes. Based on the benefits mentioned above, we use PDMS to package the pressure cavities of the silicon pressure sensors.
The newly developed pressure sensors by this new method have been tested subject to different pressure conditions.(The maximum pressure for testing is 300 psi.) The output signals of the new sensors with PDMS packaging meets the performance requirement of good sensitivity and hermetic sealing.

目錄
中文摘要………………………………………………Ⅰ
英文摘要………………………………………………Ⅱ
目錄…………………………………………………....Ⅳ
圖目錄…………………………………………………Ⅵ
表目錄…………………………………………………Ⅸ

第一章	緒論…………………………………………..1
1-1	研究動機…………………………………………..…1
1-2	研究目的…………………………………………..…2
1-3	文獻回顧…………………………………………..…3
1-4	研究架構…………………………………………..…5
第二章	壓阻式壓力感測器與PDMS介紹………….7
2-1  壓阻式壓力感測器……………………...…………..7
2-2  PDMS基本特性及介紹……………………………..8
2-2-1 PDMS的材料特性……..……………………..8
	 2-2-2 PDMS之優勢…………………………...……..10
第三章	製程…………………………………………16
3-1	矽質感測薄膜晶片製程……………………………16
3-1-1 製程介紹……………………………………….16
3-1-2 背面蝕刻………………………………...…….18
	3-2  PDMS基底製程…………………………...……….20
	3-3  封裝…………………………………………………23
第四章	實驗設備與測試……………………………25
4-1	實驗設備……………………………………………25
4-2	測試…………………………………………………27
第五章	結果與討論…………………………………28
第六章	結論…………………………………………33
6-1	總結……………………………………………….33
6-2	未來改進建議…………………………....……….35
參考文獻………………………………………………37
附錄A	硼離子掺雜…………………...……….……40
附錄B	PDMS與矽晶片鍵合強度測試…………….42





圖目錄

圖 1-1 研究架構示意圖………………………………………6
圖 2-1 壓力薄膜構型剖面示意圖..…………………….…….7
圖 2-2 PDMS材料化學鍵結結構….....……………………9
圖 2-3 以毛細管在PDMS上製作對外孔洞…………..……13
圖 2-4 利用玻璃毛細管在PDMS上
製作之圓形流道........…..………………………...14
圖 2-5 利用五層PDMS堆疊之三維微流道………………..15
圖 3-1 壓力感測器製造流程………………………………..17
圖 3-2 晶片背面蝕刻流程圖………………………………..19
圖 3-3 保護治具………………...…………………………...19
圖 3-4 薄膜下方空腔結構.………………………..………...20
圖 3-5 PDMS與矽晶片母模……..…………………………21
圖 3-6 PDMS與鐵氟龍圓盤…...…………………………...21
圖 3-7 脫膜後之500μm厚PDMS薄膜……………………22
圖 3-8 脫膜後之45μm厚PDMS薄膜...…..……………….22
圖 3-9 壓力感測器晶片與PDMS封裝接合………………..24
圖 3-10 以500μm厚PDMS薄膜封裝之壓力感測器…..…24
圖 3-11 以45μm厚PDMS薄膜封裝之壓力感測器………24
圖 4-1 壓力測試機台...…...…………………………………26
圖 4-2 數據擷取機……...…...………………………………26
圖 4-3 設備連接示意圖…......………………………………26
圖 4-4 壓力感測器插入插卡式連接器…...…...……………27
圖 5-1 #4號壓力感測器以Pyrex #7740
玻璃封裝之輸出電壓………………………………...29
圖 5-2 #4號壓力感測器以500μm厚PDMS
封裝之輸出電壓…………………………………...…30
圖 5-3 #4號壓力感測器以45μm厚PDMS
封裝之輸出電壓………………………………………30
圖 5-4 #5號壓力感測器以Pyrex #7740
玻璃封裝之輸出電壓…….………………...………...31
圖 5-5 #5號壓力感測器以500μm厚PDMS
封裝之輸出電壓……………………………...………31
圖 5-6 #5號壓力感測器以45μm厚PDMS
封裝之輸出電壓…..……………………………….…32
圖 B-1 鋼製框架…………………………………………….43
圖 B-2 鋁製掛具…………………………………………….43
圖 B-3靜力量測示意圖……………………………………..43
圖 B-4 PDMS本體破裂狀況………………………………..44

















表目錄

表 2-1 壓力薄膜幾何參數……………………………………8
表 3-1 PDMS薄膜製程參數…………………………………22
表 5-1 三種不同封裝材之#4號壓力感測器性能比較…….30
表 5-2 三種不同封裝材之#5號壓力感測器性能比較…….32

參考文獻

1.	D. Tandeske, Pressure sensors selection and application, Marcel dekker, pp. 51-54.(1991)
2.	J. B. Nysaether, A. Larsen, B. Liverod and P. Ohlchers, “Measurement of packagine-induced stress and thermal zero shift in transfer molded silicon piezoresistive pressure sensors,” J. of Micromechanics and  Microengineering, Vol. 8, No. 2, pp. 168-171(1998).
3.	K. Schjolberg- henriksen, G. U. Jensen, et al, “Sodium contamination in integrated MEMS packaged by anodic bonding,” IEEE Proc. MEMS’03, pp. 626-629(2003).
4.	D. Armani, C. Liu and N. Aluru, “Re-configurable fluid circuits by PDMS elastomer micromachining,” IEEE Proc. MEMS’99, pp. 222-227(1999).
5.	G. Wallis and D. I. Pomerantz, “Field assisted glass-metal sealing,” J. Appl. Phys., Vol. 40, pp. 3946-3949(1969).
6.	W. H. Ko, J. T. Suminto and G. J. Yeh, Bonding techniques for microsensor, micromachining and micropackaging of transducers, Elsevier Science Publishing, pp. 41-61(1985).
7.	P. Krause, M. Sporys, et al, “Silicon to silicon anodic bonding using evaporated glass,” TRANSDUCERS '91, pp. 978-981(1991).
8.	J. H. Quenzer and W.	Benecke, “Low-temperature silicon wafer bonding,” Sensors and Actuators, A32, pp. 340-344(1992).
9.	W. P. Eaton, S. H. Risbud and R. L. Smith, “Silicon wafer-to-wafer   bonding at T< 200 degree C with polymethylmethacrylate,” Appl. Phys. Lett., Vol. 65, pp. 439-441(1994).
10.	Q. Y. Tong and U. Gasele, “A model of low temperature wafer bonding and its applications,” J. Electrochem Soc., Vol. 146, No. 5, pp. 1773-1779(1996).
11.	A. Berthold, L. Nicola, et al, “Glass-to-glass anodic bonding with standard IC technology thin films as intermediate layers,” Sensors and Actuators, A82, pp. 224-228(2000).
12.	S. Chen, M. Chen, et al, “Research on wafer scale bonding method based on gold-tin eutectic solders[MEMS packaging],” Proc. Electronic Packaging Technology, pp. 187-189(2003).
13.	王信雄， 「新型高壓力負載微型壓力計之設計製造」，碩士論文，淡江大學機械與機電工程學系，92年七月。
14.	C. S. Smith, “Piezoresistance effect in germanium and silicon,” Physical Review, Vol. 94, No. 1, pp42-49(1954).
15.	K. Yamada, M. Nishihara and S. Shimada, “Nonlinearity of the piezoresistance effect of p-type silcon diffused layers,” IEEE Transactions on Electron Devices, Vol. 29, No. 1, pp71-77(1982).
16.	李俊賢， 「可攜式無閥壓電微幫浦之設計製作與應用」，碩士論文，國立台灣大學應用力學研究所，89年七月。

17.	M. A. Unger, H. P. Chou, et al., “Monolithic microfabricated valves and pumps by multilayer soft lithography,” Science, Vol. 288, pp. 113-116(2000).
18.	J. S. Go and S. Shoji, “A disposable, dead volume-free and leak-free in-plane PDMS microvalve,” Sensors and Actuators, A114, pp. 438-444(2004).
19.	J. H. Kim, C. J. Kang and Y. S. Kim, “A disposable polydimethylsiloxane-based diffuser micropump actuated by piezoelectric-disc,” Microelectronic Engineering, Vol. 71, No. 2, pp. 119-124(2004).
20.	B. Samel, J. Melin, P. Griss and G. Stemme, “Single-use microfluidic pumps and valves based on a thermally responsive PDMS composite,” IEEE Proc. MEMS’05, pp. 690-693(2005).
21.	M. Agarwall, R. A. Gunasekaran, P. Coane, et al., “Polymer-based variable focal length microlens system,” J. of Micromechanics and Microengineering, Vol. 14, No. 12, pp. 1665-1673(2004).
22.	S. Camou, H. Fujita and T. Fujii, “PDMS 2D optical lens integrated with microfluidic channels: principle and characterization,” Lab on a Chip, Vol. 3, Issue 1, pp. 40-45(2003).
23.	K. Hoshino and I. Shimoyama, “An elastic thin-film microlens array with a pneumatic actuator,” IEEE Proc. MEMS’01, pp.321-324(2001).
24.	H. Saito, K. Hoshino, et al., “Compound eye shaped flexible organic image sensor with a tunable visual field,” IEEE Proc. MEMS’05, pp. 96-99(2005).
25.	K. Hosokawa, K. Hanada and R. Maeda, “A polydimethylsiloxane(PDMS) deformable diffraction grating for monitoring of local pressure in microfluidic devices,” J. of Micromechanics and Microengineering, Vol. 12, No. 1, pp. 1-6(2002).
26.	Y. Tung and K. Kurabayashi, “A nanoimprinted strain-induced reconfigurable polymer micro-optical grating,” IEEE Proc. MEMS’05, pp. 243-246(2005).
27.	S. Li and S. Chen, “Polydimethylsioxane fluidic interconnects for Microfluidic Systems,” IEEE Transaction on Advanced Packaging, Vol. 26, Issue 3, pp. 242-247(2003).
28.	B. H. Jo, M. Linda, V. Lerberghe, et al., “Three-dimensional micro-channel fabrication in polydimethylsiloxane(PDMS) elastomer,” J. Microelectromechanical Systems, Vol. 9, No. 1, pp. 76-81(2000).
29.	R. Pantoja, J. M. Nagarah, D. M. Starace, et al., “Silicon chip-based patch-clamp electrodes integrated with PDMS microfluidics,” Biosensors and Bioelectronics, Vol. 20, Issue 3, pp. 509-517(2004).
30.	C. H. Hsu, C. C. Chen and A. Folch, “ “Microcanals” for micropipette access to single cells in microfludic environments,” Lab on a Chip, Vol. 4, Issue 5, pp. 420-424(2004).
31.	J. Narasimhan and I. Papautsky, “Polymer embossing tools for rapid prototyping of plastic microfluidic devices,” J. of Micromechanics and Microengineering, Vol. 14, No. 1, pp. 96-103(2004).


32.	C. W. Li, C. N. Cheung, J. Yang, et al., “PDMS-based microfluidic device with multi-height structures fabricated by single-step photolithography using printed circuit board as masters,” Analyst, Vol. 128, Issue 9, pp. 1137-1142(2003).
33.	H. K. Wu, T. W. Odom, D. T. Chiu, et al., “Fabrication of complex three-dimensional microchannel systems in PDMS,” J. of American Chemical Society, Vol. 125, Issue 2, pp. 554-559(2003).
34.	C. P. Steinert, N. Schmitt, E. Deier, et al., “A novel fabrication method for hybrid, microfluidic devices,” IEEE Proc. MEMS’05, pp. 552-555(2005).
35.	P. Krulevitch, W. Bennett, J. Hamilton, et al., “Polymer-based packaging platform for hybrid microfluidic systems,” Biomedical Microdevices, Vol. 4, No. 4, pp. 301-308(2002).
36.	S. Rimdusit and H. Ishida, “Gelation study of high processability and high reliability ternary systems based on benzoxazine, epoxy, and phenolic resins for an application as electronic packaging materials,” Rheologica Acta, Vol. 41, No. 1-2, pp. 1-9(2002).
37.	H. Krassow, F. Campabadal and E. Lora-Tamayo, “Wafer level packaging of silicon pressure sensors,” Sensors and Actuators, A82, pp. 229-233(2000).
38.	Z. Chu, “Flexible package for a tactile sensor array,” Proc. National Sensor Conf., pp. 121-124(1996).
39.	J. C. L&ouml;tters, W. Olthuis, P. H. Veltink and P. Bergveld, “The mechanical properties of the rubber elastic polymer polydimethylsiloxane for sensor applications,” J. of Micromechanics and Microengineering, Vol. 7, No. 3, pp. 145-147(1997).
40.	P. Z. Chang and L. J. Yang, “A method using V-grooves to monitor the thickness of silicon membrane with μm resolution,” J. of Micromechanics and Microengineering, Vol. 8, No. 3, pp.182-187(1998).
41.	張志成， 「微機電感測元件之可調壓調溫測試系統研製」，碩士論文，淡江大學機械與機電工程學系，93年六月。
42.	J. C. Lotters, W. Olthuis, P. H. Veltink and P. Bergveld, “Polydimethylsiloxane as an elastic material applied in a capacitive accelerometer,” J. of Micromechanics and Microengineering, Vol. 6, No. 1, pp. 52-54(1996).