高耐蝕塗膜鋁散熱片之塗裝製程及品質影響探討

Effects of Coating Process to the High Corrosion Resistant Precoated Aluminum Film

一般塗膜鋁箔散熱片表面耐蝕性，仍無法滿足高耐蝕鋁散熱片的耐蝕規格需求。因此以特殊的二塗二烤（2C2B）製程，及高耐蝕一塗一烤（1C1B）塗料來提昇塗膜散熱片的耐蝕性，同時兼顧塗膜鋁散熱片的親水等其餘特性。本研究以引進的塗料，配合產製製程條件的設定，開發高耐蝕塗膜鋁散熱片。使產品耐蝕性達到鹽霧試驗750小時，RN值≥9.3；實用親水性接觸角≤50° 等塗膜主要品質標準。研究內容包括：⑴實驗室搭配可能的面漆及底漆，塗製、評估二塗二烤（2C2B）塗膜可行性。⑵篩選一塗一烤（1C1B）塗料，製成合格的一塗一烤（1C1B）塗膜。⑶以實驗計劃法探討：塗料種類、製程條件烘焙溫度範圍、塗膜厚度及前處理藥劑量..等變因，了解這些因素對1C1B塗膜品質的影響。研究結果顯示：2C2B塗膜組合及篩選的1C1B 塗膜，皆可產製高耐蝕塗膜鋁散熱片，750小時鹽霧耐蝕性，RN值≥9.3，實用親水性接觸角≤50°，其餘塗膜品質皆達標準。另，經由直交實驗及S/N比分析顯示，塗膜親水性受塗料種類及膜厚影響較大；耐蝕性則受塗膜厚度及鉻酸處理量影響較明顯。建立產製高耐蝕塗膜鋁散熱片技術，可針對產品需求作塗膜性的調整。

The quality of general pre-coated aluminum fin stock cannot reach the high corrosion resistance (Salt spray 750 hrs). A special manufacturing process 2C2B is applied with coating materials then also the new 1C1B coating materials are evaluated.This study develops the coating process and evaluates the suitable coating materials for the high corrosion resistance product. The quality of coated fin stocks will meet the criterion of 750 hrs salt spray test RN≥9.3 and hydrophilic acceleration test, contact angles≤50 . The approach of experiments included: (1) Lab test for the 2C2B manufacturing process. (2) Lab evaluation for the 1C1B coating materials. (3) Experimental planning methods to investigate the effects of coating materials, chromium pretreatment, baking temperature and film build thickness. The results showed that the selected coating materials could produce the pre-coated fin stocks and reach the characters of fin stock. The results of orthogonal experiment and the analysis of signal-to-noise(S/N) ratio also shows corrosion resistance significantly affected by chromium, film build thickness, and the hydrophilic characters significantly affected by the coating materials. The technology established in this study will be used to manufacture and adjust the character of the precoated fin stock.