Glass Thinning by Fluoride Based Compounds Solution with Low Hydrofluoric acid Concentration

In this study, a new wet etching method and the solution for thinning the glass with the thickness below 100 were investigated. For the preparation of etching solution with low hydrofluoric acid, it was effective to use $NH_4F$ or $NH_4HF_2$ as a main ingredient with the addition of sulfuric acid or nitric acid. Influence of the composition of mixed acid solution and the temperature on the etching rate was investigated. The addition of anionic surfactant provides the function to prevent the adhesion of sludge generated by the etching reaction. A new wet etching pilot device equipped with streaming generation parts was used to test etching of commercial non-alkali glass and soda lime glass. The non-alkali glass with the thickness of 640 and soda lime glass with the thickness of 500 were etched to 45 and 100 , respectively, by using the pilot device. After the etching by pilot device, the roughness degree of the glass surface was maintained at 0.01∼0.02 .