觸控面板玻璃基板蝕刻污染防治技術

近年觸控應用產品蓬勃發展，其中單片式玻璃觸控面板(One Glass Solution，OGS)，將ITO玻璃與保護玻璃整合成一片玻璃，具有輕薄、節省成本及透光率較佳優勢。單片式玻璃觸控面板主要材料－玻璃基板佔據關鍵因素，玻璃依其成分特性分為鋁矽酸鹽玻璃及鈉玻璃二種，為增強玻璃強度使其具有不易變形以及更堅硬、更耐刮等優點需再經由化學強化製程，即玻璃浸泡高溫硝酸鉀後置換玻璃的鈉離子與硝酸鉀的鉀離子，實現玻璃強化的目的。然而，業界主要採用較便宜的鈉玻璃基板，經化學強化製程後易殘留鉀離子析出物，導致後續黃光製程BM(Black Matrix) 光阻曝光、顯影再經由ITO sputter、蝕刻形成pattern時採用的蝕刻液氯化鐵（FeCl3）滲入BM光阻而與玻璃表面鉀離子析出物反應出氯化鉀（KCl）而產生白點污染。本研究以不更換蝕刻液為前提，為解決鈉玻璃基板上之白點污染，我們在化學強化後的清洗製程再加入溶劑浸泡程序，以去除殘留的鉀離子析出物，避免蝕刻時產生白點污染。實驗方法上，我們用多種不同溶劑配方與調整浸泡時間進行玻璃清潔測試，並檢視改善效果。實驗結果可看出以pH 1.5酸性溶劑浸泡30分鐘為找出的可行方案中具最佳效益。

關鍵字

單片式玻璃觸控面板；化學強化；黃光製程；玻璃基板

並列摘要

In recent years, the touch application products have been flourishing, among them, the mainstream technology is One Glass Solution(OGS),integrate cover lens and ITO glass to one glass has the advantages such as thinner ,cost savings and better transmittance. Main material of OGS – glass substrate is a key factor; the glass can be used Aluminosilicate glass or Soda-lime glass according to its composition characteristics. In order to enhance the glass strength and make it with the advantages of being bendable, harder and more anti-scratch, chemical strengthening process is needed, therefore the process is glass placed in a hot salt bath. Smaller sodium ions leave the glass, and larger potassium ions from the salt bath replace them. These large ions take up more room and are pressed together when the glass cools, producing a layer of compressive stress on the surface of the glass to achieve the objective of glass strengthening. However, the industry mainly adopts cheaper soda-lime glass substrate, and potassium ion precipitate is easily left after chemical strengthening process, in the subsequent process of coating color photoresist to form black matrix, the etching liquid Ferric chloride (FeCl3) will penetrate into the photoresist and has chemical reaction with the potassium ion precipitate on the glass surface to produce potassium chloride (KCl) and therefore generate white defect pollution. This research is to resolve the white defect pollution on soda-lime glass substrate under the premise of not changing the etching liquid, in the cleaning process after chemical strengthening, we will add in solution soaking procedure to remove the residual potassium ion precipitate, so as to avoid generating white defect pollution in etching. In the aspect of experimental method, we use multiple different solution formulas and adjust soaking time to conduct glass cleaning test and inspect on the improvement effect. From the experimental result, we can tell that soaking with pH 1.5 acidic solution for 30 minutes is the feasible plan of optimum effectiveness.