| 摘要 |
The invention relates to a substrate disk consisting of two interconnected substrates (1, 2), with a centre hole (3). The inventive substrate disk is o f an especially good quality and can be produced with simple means. According to the invention, one of the substrates (1, 2) from which the disk is formed ha s at least one projection (5) on the edge of the centre hole, said projection projecting away from the substrate surface (6). |
