|Abstract: ||(110)矽質微型熱交換器的問世,為近十年來興起的微機電技術,再度開創了一個全新的領域。新型微型熱交換器的加工法突破過去以金屬材質切削成形的傳統,而是以精密新穎且成熟的半導體製程之光蝕刻技術蝕刻加工矽晶圓,並配合金屬中間層擴散接合法,將數十片具有大量微細通道的矽質基板,疊合而成一交流型板式熱交換器。 (110)矽質微型熱交換器之核心熱交換區域大小約為0.918cm/sup 3/,其熱傳面積密度可達15,294m/sup 2//m/sup 3/;測試時是以去離子水為工作流體,測得其流場均為層流,雷諾係數均保持在820以下;當壓力落差達2.47bar時,流量可達4.5l/min以上,且進出口的對數平均溫差可達30K以上;微型熱交換器的熱傳量可達5kW,使其整體熱傳係數為24.7kW/m/sup 2/-K,體積熱傳係數188.5MW/m/sup 3/-K。 由於矽本身除了會被少數化學藥品侵蝕外,不論在強度上、熱傳上、或抗腐蝕方面均有優良的性質,使其適合應用在高溫或具腐蝕性的流體中,對電子元件的散熱、核能發電、航太與熱機零件的熱交換、甚至在生化醫學方面都具有前瞻性的效益。|
The micro cross flow heat exchanger made of (110)- orientated silicon is fabricated by bulk micromachining that is compatible with semiconductor producing processes, and wafers with hundreds of high aspect ratio channels are bonded together by diffusion bonding with aluminum as medium layers. The core of the micro heat exchanger is about 0.918cm/sup 3/, and the density of the heat transfer area is 15,294m/sup 2//m/sup 3/. Using pure water as the working fluid, the Reynolds Numbers show that the fluid field is always laminar flow, and as the maximum pressure drop reaches 2.47 bar, the flow rate is greater than 4.5l/min. The heat transfer measured between hot and cold fluid is 5 kW; the log mean temperature is greater than 30K, and that makes the overall heat transfer coefficient up to 24.7kW/m/sup 2/-K, corresponds to a volumetric heat transfer coefficient of 188.5MW/m/sup 3 /-K. Except reacted on a few special chemicals, silicon has excellent properties in mechanics, heat transfer, and anticorrosion, so the (110) silicon based micro heat exchanger suits for the operations at high temperature or in corrosive fluids. The extremely small heat sink appears to have a variety of current and potential applications in areas such as micro-electronic cooling and biomedical processes where high heat transfer power are required with little weight and small volume.