微型晶片級Pirani真空計之設計與實現

Design and Implementation of Miniaturized Chip Level Pirani Vacuum Gauge

孫翊強(Yi-Chiang Sun)

指導教授 ： 方維倫

國立清華大學/工學院/動力機械工程學系/碩士(2014年)

摘要

本研究以TSMC 0.18um 1P6M CMOS標準製程來設計並實現Pirani真空計。一般而言，Pirani真空計由發熱源與散熱片所組成，利用空氣熱傳導係數隨壓力而變的特性，發熱源所產生的熱透過空氣傳遞至散熱片的熱量將會不同，因此可利用此特性來量測壓力變化。本研究提出新型態的結構設計，使元件的熱阻(Thermal resistance)可以上升，透過熱阻的上升使元件在相同功率下可以有較高的升溫，因而增加熱源與散熱片間的熱傳效率，以提升元件的性能。本研究共提出兩種新型結構設計，以達到在相同面積大小的情況下增加元件使用性能的目標。第一種結構設計為互補式內置散熱片結構設計，此設計具有以下特點：(1)熱源上挖洞的設計可以增加元件的熱阻。(2)內置散熱片結構設計彌補因挖洞而損失的有效面積。(3)以金屬作為加熱源使感測材料與散熱源間沒有太多二氧化矽阻隔，大幅提升元件靈敏度。(4)可輕易與其他CMOS-MEMS元件作封裝整合，以檢測封裝內部真空度。第二種結構設計為互補式凸型散熱片與凹槽熱源結構設計，此設計具有以下特點：(1)凸型散熱片垂直整合於凹槽熱源中可增加有效散熱面積。(2)凹槽熱源設計可以增加元件的熱阻。(3)可輕易與其他CMOS-MEMS元件作封裝整合，以檢測封裝內部真空度。

關鍵字

CMOS-MEMS ； Pirani ； 真空計 ； 熱阻 ； 封裝

並列摘要

This study employs standard TSMC 0.18um 1P6M CMOS process to design and implement Pirani vacuum gauge. Generally, Pirani vacuum gauge consists of heater and heat sink units. The heat generated by heater is transferred to the heat sink through gas molecules whose thermal conductivity depends on their pressure. This study proposes a novel structure design to improve the performance of Pirani vacuum gauge which is increasing the thermal resistance of heater. By increasing thermal resistance, the heater can obtain higher temperature comparing to typical one under the same power heating. Therefore, the efficiency of heat transfer can be increased and further improve the performance of the gauge. This study presents two different structures to achieve the goal of improving the device performance without changing device footprint size. Firstly, this study presents a complementary inbuilt heat sink design. This design has the following advantages: (1) The hole in heater can increase thermal resistance of heater, (2) The inbuilt heat sinks compensate the lost active area, (3) The heating and sensing material is composed of metal, so there are no much SiO2 to influence the heat transfer, and (4) Easy integration with packaged CMOS-MEMS devices for pressure monitoring. Then, this study presents another complementary bump heat sink and cavity heater design. This design has the following advantages: (1) The bump heat sink vertical integrates with cavity heater increases the active area, (2) The cavity in heater increases thermal resistance of heater, and (3) Easy integration with packaged CMOS-MEMS devices for pressure monitoring.

並列關鍵字

HASH(0xd47c2d0) ； Pirani ； Vacuum gauge ； Thermal resistance ； Package

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