- 學位論文
塗裝單壁奈米碳管鰭片熱電致冷晶片散熱效率與熱變形之研究
Investigation of Heat-Dissipation Efficiency and Thermal Deformation of TECs with SWCNT Coated Heat Sink
摘要
熱電致冷器(Thermoelectric Cooler, TEC)是一種將電能轉換為熱能的裝置，操作過程中存在溫度梯度形成冷面與熱面，因結構內各材料熱膨脹係數不匹配造成電子元件間互相牽制，經長時間反覆使用後，內部會產生熱應力與熱變形，易導致元件損壞。 本研究利用兩套三維數位影像相關(Three Dimensional Digital Image Correlation, 3D-DIC )應變量測系統，分別量測無加裝鰭片與有加裝鰭片之127對品牌A與品牌B之TEC試片表面與側面P型和N型半導體之變形。探討在不同電流下TEC的應變資訊，並利用應變資訊與溫度分布來探討TEC的品質。結果顯示所有TEC表面與側面之變形量，均隨著電流越大，應變越大。從應變量測系統中也可得到TEC試片應變分布狀況，並利用多組試片實驗，驗證了品牌B之TEC品質較佳。 為增加散熱率，使用單壁奈米碳管(Single-Walled Carbon Nanotube, SWCNT)均勻塗佈於鋁擠型散熱鰭片表面，成功提升鰭片散熱效果；提高TEC於加裝鋁擠型散熱鰭片使用時，所能負荷之最大電流。由變形方面得到加裝奈米碳管散熱鰭片之TEC整體應變量趨勢比加裝鋁擠型散熱鰭片小。由溫度方面也得知加裝奈米碳管散熱鰭片之TEC整體溫度趨勢下降。未來有可能利用奈米碳管散熱鰭片以取代散熱風扇用於中小電流TEC之使用，除了增加TEC的使用壽命，也可降低成本與減少電子元件受風扇振動之影響。
並列摘要
Thermoelectric cooler (TEC) is a device which converts electrical energy into heat energy. The primary principle of the TEC is the Peltier effect. Thermoelectric cooler is a sandwich structure consisting of many different materials. When a direct current is applied, thermal stress and thermal deformation are unavoidably produced in the TEC due to the temperature gradient. Moreover, due to the mismatch of thermal expansion coefficient between component materials of the TEC, the TEC may be out of work after an extended period of practice. In this thesis, two sets of three dimensional digital image correlation (3D-DIC) systems were adopted to measure the deformation of two different TECs, i.e. TEC_A and TEC_B, of 127 pairs of p-type and n-type semiconductors with and without the heat sink, respectively. Strains of the TEC under different currents were measured, and the quality of the TEC was investigated by the strain and temperature distributions. Results showed that the strain becomes higher as the current increased. The quality of TEC_B was also found better based on results of the strain distribution. To enhance the cooling effect, single-walled carbon nanotube (SWCNT) was used to coat on the surface of the heat sink, and the cooling effect of the heat sink was found successfully improved. The strain of the TEC is smaller when the SWCNT heat sink was added, and the overall temperature distribution was also decreased. In the future, it is possible to use the SWCNT heat sink to replace the cooling fan for TECs under low and medium current. In addition to increase the service life of TECs, cost and the vibration produced from the cooling fan can also be reduced.