以奈米金懸浮液製備導電薄膜之研究

有鑑於奈米金屬粒子具較塊材低之熔點，如製備為懸浮液以drop on demand噴墨技術，將可於較低的製程溫度獲得所需圖案之導電點/線，無須使用微影製程。本研究製備奈米金懸浮液，探討基板與熱處理參數對塗佈之金薄膜連續性與其與基材之接合情形之影響。實驗結果顯示，在銅基板上之薄膜擁有最佳之連續性與緻密度，鎳基板之結果則優於鋁。在高於奈米金熔點溫度條件下進行熱處理可以得到連續性佳、且與基板接合強度理想之金膜。值得注意的是在經適當後續製程，以本法製備之金膜接合強度優於以濺鍍法製備者。

It is well known that nano-sized metals exhibit a considerably lower melting point compared to bulk materials. By using a proper deposition technique, e.g., drop-on-demand ink jet printing, suspensions containing nanoparticles could be applied to the manufacturing of desired conducting patterns. Thus, electric micro-interconnects for microelectronics and packaging could be obtained without the use of lithography etching. In this study, suspensions with gold nanoparticles of average size 3.17 nm were prepared and spin coated onto several commonly used electronic substrates, Cu, Ni and Al, and then thermally processed under a protective atmosphere. Experimental results show that the degree of continuity of the coated film on the Cu substrate was better than that on the Ni substrate, which was in turn better than the Al substrate. It was also evidenced that isothermally heating the suspension at 300 °C, a temperature greater than the melting point of the nanoparticles used, could obtain fine gold deposits with acceptable adhesion. Worthy of notice is that after a proper curing treatment, gold layers by depositing nanoparticle suspension exhibited superior adhesion to those by sputtering.