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PMMA光盘基片材料的历史背景 PMMA(Polymethyl Methacrylate,中文学名是聚甲基丙烯酸甲酯,俗称有机玻璃)早在1980年就被用来制造激光影碟(Laser Disc,简称LD)。当光盘发展到厚度为直径1.2 cm的CD单层基片时,由于PMMA吸收湿气造成CD翘曲的问题不容易控制,而且当时所用的高能溅射设备会破坏PMMA基片的表面,所以吸水性较低和玻璃转移温度较高的PC(Polycarbonate,中文学名是聚碳酸酯)就取代了PMMA。PC的抗冲击强度虽然很好,耐人寻味的是这一特性却不是当时选择PC的首要考虑。 DVD是由两片0.6 mm厚的基片贴合而成,对称结构使光盘基片翘曲的问题变得易于控制。
Background History of PMMA Substrate Materials PMMA (Polymethyl Methacrylate, Chinese name is polymethylmethacrylate, commonly known as plexiglass) was used to make Laser Disc (LD) as early as 1980. When the disc developed to a CD monolayer substrate with a thickness of 1.2 cm in diameter, the problem of warpage of the CD due to moisture absorbed by the PMMA was not easily controlled and the high-energy sputtering equipment used at that time destroyed the surface of the PMMA substrate so water absorption PC (Polycarbonate, Chinese name is polycarbonate) and lower glass transition temperature to replace the PMMA. Although the impact strength of PC is good, intriguing is that this feature is not the primary consideration when choosing a PC. The DVD is made of two 0.6-mm-thick substrates bonded together. The symmetrical structure makes it easy to control the problem of the disc substrate warpage.