Patent ID: 7000312

Claim:
A method for mounting a circuit board device on a motherboard, the circuit board device including a substrate having a front surface on which an electronic component is mounted, a rear surface to be mounted on the motherboard, and end surfaces, end-surface electrodes which are provided on the end surfaces and to which the electronic component is connected, lands which are provided on the rear surface and are connected to the end-surface electrodes and which are to be soldered to the motherboard together with the end-surface electrodes, the lands each including a mainland connected to each of the end-surface electrodes and a sub-land disposed at a distance therefrom, and partitions each provided on the rear surface side for separating the mainland from the sub-land, the method comprising the steps of: preparing solder; forming protruding portions which are composed of the solder covering the mainlands and which protrude from the rear surfaces by melting the solder in order to flow on the end-surface electrodes toward the mainlands; placing the circuit board device on the motherboard in the state in which the protruding portions face respective wire patterns of the motherboard; melting the solder so as to adhere to the wire patterns; and allowing the solder present at the mainland sides to flow over the partitions and into the respective sub-land sides, whereby the mainlands and the respective sub-lands are connected to the respective wire patterns of the motherboard.