| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to effectively utilize the space of a substrate to be exposed and to make printable mask information to the outer peripheral part of the substrate to be exposed by subjecting the outer peripheral part of a printed circuit board to proper light shielding and exposing. SOLUTION: A light shielding device 2 is disposed between a light source device 6 and a glass mask 1. The light shielding device 2 may be constituted as part of the light source device 6 or as an independent device and is composed of light shielding plates 20 to 23 and air cylinders 25 to 28 for advancing and retreating these plates onto the mask outer peripheral part FM of the glass mask 1. The respective light shielding plates 20 to 23 are capable of selectively covering substrate information 10 to 13 so as to prohibit the exposure of these portions. While the mask outer peripheral part FM of the glass mask 1 is properly shielded of light, the part is exposed, thereby, the prevention of the occurrence of the useless space at the contact boundaries of the respective regions A to D is made possible. Even more, all of the substrate information 10 to 13 in the mask outer peripheral part FM of the glass mask 1 are printed to the outer peripheral part FW of the substrate W. |
