A fixture to enable correct positioning of components in surface mount technology (SMT) field includes a tray, a positioning mechanism, at least one first upper magnet, at least one second upper magnet, and at least one lower magnet. The tray has at least one positioning hole. The positioning mechanism includes a base member, at least one sliding assembly, and at least one positioning post. The sliding assembly is slidably mounted to the base member. The positioning post is mounted to the base member, and disposed in the positioning hole of the tray. The first upper magnet and the second upper magnet are attached to the tray. The lower magnet is attached to the sliding assembly. The tray and the positioning mechanism are repulsive when the lower magnet aligns with the first upper magnet but are attracted when the lower magnet aligns with the second upper magnet.