抗靜電點火晶片之設計與研製

Abstract

微型點火晶片是一種具發火能量低、啟爆時間短且可靠度高的引燃器，如今已被廣泛應用於汽車、航空及國防工業。本文改良點火晶片的結構設計，除了讓點火晶片仍然可以低能快速發火外，同時讓它具有抗靜電的效果，使得點火晶片在使用上更加安全無虞。 本文的研製成品主要是利用微機電製程製作。研製的過程是在矽晶圓上製作出金屬薄膜電橋，再利用半導體技術在金電橋下製作出與電橋並聯的兩對向二極體。當晶片接觸到高壓靜電時，靜電荷可以藉由二極體的崩潰將電流傳至電橋下方的二極體迴路，以防電橋通過過量的電流而發熱誤燃。在做實驗的同時，本文也利用電子電路模擬軟體Pspice，驗證本點火晶片的結構設計是否可以在25kV的靜電放電模式下具有抗靜電的效果。模擬結果顯示改良過的晶片確實可以成功降低靜電在電橋產生的焦耳熱。 製成電橋晶片後，本文利用以高壓電容組成的擬靜電放電電路對晶片放電，測詴其是否可以承受高壓靜電且不發火。另外，在電橋的發火時間量測上，本文利用高敏感度的光二極體來接收發火訊號，藉由光二極的電壓變化判讀本晶片在低壓點火下的發火時間。 實驗結果顯示，本文所設計的晶片均能通過擬靜電放電的測詴，可以承受高壓放電而不發火，且晶片連續經過20次靜電放電亦不點燃，電橋電阻也只有些微的上升。此外，本晶片的發火非常快速，在35V、33μF的電容放電下，帄均只需要約1.5μs即可以發火。總合以上所有結果，本文所設計的微型點火晶片在量測上確實可以同時達到抗靜電及低能快速發火。

MEMS igniting chip is an outstanding electro-actuating device with low initiating energy, great igniting power, and high stability. Nowadays, MEMS igniting chip has been widely applied to various fields, such as automobile, aeronautics, and defense industries. In this thesis, the modified igniting chips which could both sustain electro-static discharges and satisfy the demand of low-energy ignition are investigated. The anti-static-charge ignition chips were fabricated via MEMS technologies. On a silicon wafer, the metal bridge was overlaid on the two opposite-direction diodes to form the integrated chip. By doing so, when electro-static charges apply to the chip, the static charge current could flow through diodes instead of the metal bridge, consequently preventing the unexpected igniting. Besides, in order to test whether the ignition chip possesses the anti-static-charge capability or not, the simulation software Pspice for electronic circuits was used to verify its performance: The results evidence that anti-static-charge ignition chip could successfully reduce the heat generated on the metal bridge. In experiments, a discharging circuit with a high-voltage was constructed carry out the measurement of static charge discharging. Moreover, by using a sensitive photodiode to detect the ignition sparkling, the signal of photodiode evidence the ignition time of the anti-static-charge ignition chip when excited by a low voltage of 35 V charged in a 33μF capacitor. In summary, the result indicated that the anti-static-charge ignition chip could release static-electro discharges, without being ignited by static electricity. Meanwhile, it could be ignited with low energy in a short time, and the activating time is 1.5μs on average.