蒸汽腔體均溫板（VCHS）為二相變化傳熱之平板式熱管，具有高熱通量與將溫度分佈至平面之能力，且已被大量使用於CPU、伺服器與高功率LED之散熱。 本文以非對稱性加熱與冷卻，針對銅質均溫板與蒸汽腔體均溫板進行均溫性、升溫速率與熱擴散係數等熱性能研究。致冷晶片(TEC)以電功率60W於均溫板左下角落進行加熱，由室溫加熱至95oC時切換為冷卻模式，配合強制對流降溫至15oC，分別使用七條熱電偶與紅外線熱影像儀進行均溫性與升溫速率量測。另以Angstrom’s Method計算銅質均溫板及蒸汽腔體均溫板熱擴散係數。 均溫板之均溫性以非對稱性加熱之平均溫度與溫差曲線進行詳細的比較。其結果顯示銅質均溫板及蒸汽腔體均溫板之熱擴散係數分別為1.17cm2/s及3.675cm2/s，且蒸汽腔體均溫板具有高均溫性是利用二相流進行熱傳導，故升降溫速率與均溫性皆優於銅質均溫板。二相流方式傳熱使蒸汽腔體均溫板具有良好的均溫性，配合快速升降溫之特性將具有更多應用，如聚合酶鏈反應（PCR）。 The vapor chamber heat spreader (VCHS) is a capillary driven planar heat pipe design with a small aspect ratio, can sustain high heat flux and even the temperature distribution on a flat plate surface. Experimental investigations are performed on copper and vapor chamber heat spreaders to study their temperature uniformity, heating rate and thermal diffusivity based on a transient asymmetric heating and cooling test (TAHCT). A thermoelectric cooler (TEC) is applied to left corner of the spreaders. Spreader transient temperatures are measured by seven thermocouples and an IR-camera respectively when TEC is heating from 25oC with a power of 60W, switching to cooling mode at 95oC, and turning off at 15oC under forced convection. The Angstrom’s Method is used to measure the thermal diffusivity of heat spreaders in this study. Temperature uniformity is evaluated by average temperature and temperature difference during heating and cooling periods. A detail description in temperature uniformity is obtained. Vapor chamber heat spreader has the better temperature uniformity and heating rate. The utilization of the two-phase fluid phenomena to spread the heat is a key factor of good temperature uniformity. The thermal diffusivity of copper heat spreader and VCHS are 1.17cm2/s and 3.67cm2/s respectively. Another potential applications for the VCHS are seen in areas where good temperature uniformity are required with high heating rate such as Real-time Polymerase Chain Reaction (PCR).