Sixth-generation glass substrates, used for the first time in the world at Kameyama Plant No. 1, measure up to 1,500 x 1,800 mm, but the eighth-generation glass substrates used at Kameyama Plant No. 2 are as large as 2,160 x 2,460 mm, even though they are only 0.7 mm thick. If both sides of an eighth-generation glass substrate were held up, the center of the substrate would sag more than 30 cm. Moreover, substrates are extremely delicate; even the smallest excessive load can cause micro cracks, rendering the substrate unusable. What’s more, the surface of glass substrates is 2,000 times smoother than that of ordinary glass. If a substrate is carelessly touched, dust stuck to the surface will result in sub-standard products and, ultimately, will affect yield rate.