摘要:
A first surface of a double-sided printed circuit board has a soldering land for heat radiation, which serves as a mounting surface for an electronic part. A land for solder absorption is formed on the second surface facing the mounting surface. Viaholes are provided and open in both the soldering land for heat radiation and the land for solder absorption at the opposite ends. Molten solder flows out from the openings of the viaholes and spreads on the land for solder absorption to suppress formation of solder balls. Cream solder is applied to the outer surface of the land for solder absorption to embed the solder and to form a solder layer.
摘要:
A method for calculating an offset of an exposure dose and a focus position in an exposure apparatus that exposes a substrate via an original includes the steps of obtaining information of a shape of a pattern formed on the substrate using the exposure apparatus, calculating a shift amount between a critical dimension contained in the information of the shape of the pattern and a reference value of the critical dimension, and calculating an offset of the focus position based on the information of the shape of the pattern, and calculating the offset of the exposure dose based on the shift amount and the offset of the focus position.