Patent ID: 7013557

Claim:
A method of manufacturing a package including an electronic component, in which the electronic component has electrodes and is packaged on a printed circuit board in which lands having border edges have been formed in a pattern of arrangement that corresponds to said electrodes by soldering said electrodes to said lands; said method comprising steps of: arranging a metal mask, in which openings are formed in a pattern corresponding to said lands, on said printed circuit board such that said openings are each positioned over respective said lands, said opening defined by edge regions surrounding said openings; filling each of said openings with solder paste; removing said metal mask; placing said electronic component on said printed circuit board such that said electrodes are each placed on said solder paste; and performing reflow of said solder paste to solder said electrodes to said lands; wherein at least one of said openings of said metal mask is formed in a shape such that portions of said edge regions have straight edges and at least a part of said edge regions are positioned inside the border edges of said lands when said metal mask is arranged on said printed circuit board; and wherein said edge regions of said at least one of said openings is in the shape of a five sided polygon forming a home plate-shape having a convex shape with a vertex facing toward said electronic component, said vertex positioned not inside the border edges of the lands; and wherein said filling step fills said at least one opening with said solder paste comprises tin-zinc (Sn—Zn) solder that does not contain lead (Pb).