| 摘要: | 本研究開發新的量測技術以決定蒸汽腔體均溫板之熱擴散係數，此係數代表材料在非穩態熱傳導時特有的性質，该值描述了材料在温度變化下熱反應的快慢。本實驗架構了一套具熱成像系統之量測平台，此平台之準確性先以暫態平面熱源法確認，再以Angstrom’s Method量測純銅以及人造石墨片之熱擴散係數，並且以相同之量測參數對蒸氣腔體均溫板進行實驗。
先以30秒、40秒、50秒、60秒不同週期與0至6公分之量測距離對30 mm×150 mm×3 mm純銅片與30 mm×150 mm×25 μm之人造石墨片進行實驗，實驗結果顯示當週期為40秒，距離為5公分時所測得之熱擴散係數與標準值比較最為準確與穩定。
最後以實驗週期40秒以及0至6公分量測距離對蒸氣腔體均溫板進行實驗。結果顯示量測距離為5公分處所得之熱擴散係數為12.168 cm2/s，相較於其它量測數據皆較為穩定；實驗中發現當量測距離與熱源點越接近時，波峰時間差也越不穩定，直接造成實驗數據的誤差。
This study develops a new measurement technique that determines the thermal diffusivity of vapor chamber heat spreader (VCHS). Thermal diffusivity is a material specific property for characterizing unsteady heat conduction. This value describes how quickly a material reacts to a change in temperature. To measure thermal diffusivity, this study developed an apparatus composed of thermal imaging system. After using Transient Plane Source Method to confirm the accuracy of this platform, technique based on Angstrom’s Method was set up to measure the thermal diffusivity of copper and graphite sheet, then use the same experimental parameters to test the VCHS.
Firstly, this method was tested for samples of copper (30 mm × 150 mm × 3 mm) and graphite (30 mm × 150 mm ×25 μm) at various sine wave cycle heat input (30 sec., 40 sec., 50 sec., 60 sec.) and different measurement distance (0 cm, 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm) respectively. Comparing with the standard value, the results showed the optimal measurement cycle and distance were 40 sec, and 5 cm.
Finally, measurement of VCHS was conducted at period of 40 sec. and different measurement distance 0-6 cm, respectively. According to the experimental results at 5 cm of the measurement distance shows more stable results, the thermal diffusivity obtained was 12.168 cm2 / s. It was also found that the closer to the heating source, the bigger of the error can get. |
