Patent ID: 8975533
Filing Date: 2015-03-10
Classification: B23K,H05K,Y02P

Abstract:
1. A printed wiring board that has a solder land group used for placing a quad flat package integrated circuit (IC), the solder land group including front solder-land groups and rear solder-land groups, comprising: rear solder-drawing lands that are positioned adjacent to the rear solder-land groups, that have front edges each of which is substantially parallel to a longitudinal direction of solder lands constituting the rear solder-land group and has a length approximately equal to or longer than that of the solder lands in the longitudinal direction, that are completely separated into two parts in a horizontal direction with respect to a traveling direction of solder flow such that a gap between the respective separate rear solder-drawing lands is made wider in a rearward portion between the rear solder-drawing lands than in a frontward portion between the rear solder-drawing lands that is positioned forward in the traveling direction, and that have a slit substantially parallel to the longitudinal direction near the front edge, wherein the gap between the two separate rear solder-drawing lands from a front end to a predetermined point has a first constant width, and the gap between the two separate rear solder-drawing lands in a rearward portion relative to the predetermined point has a second constant width wider than the first constant width.