Package structure and method of forming thereof

A package structure, comprising:

• a semiconductor device;
• a first redistribution line electrically connected to the semiconductor device;
• a dielectric layer over the first redistribution line and having a first opening therein;
• a first conductive bump partially embedded in the first opening and electrically connected to the first redistribution line;
• and
• a moisture-penetration preventing structure surrounding a bottom portion of the first conductive bump, wherein a top portion of the first conductive bump is free of the moisture-penetration preventing structure, the moisture-penetration preventing structure has a portion below a topmost location of the dielectric layer, the portion of the moisture-penetration preventing structure has a width decreasing as a distance from the first redistribution line decreases, the portion of the moisture-penetration preventing structure has a pointed end at a bottommost position of the portion of the moisture-penetration preventing structure and a curved surface extending from the pointed end along the dielectric layer, when viewed from above, the moisture-penetration preventing structure includes a plurality of overlapping circular patterns, and circumferences of neighboring two of the plurality of overlapping circular patterns meet to form a sharp point.

A package structure, comprising:

• a semiconductor die;
• a dielectric layer over the semiconductor die;
• a solder ball partially in the dielectric layer and electrically connected to the semiconductor die;
• and
• a printed sealing structure abutting the solder ball, wherein an interface between the printed sealing structure and the dielectric layer meets an interface between the printed sealing structure and the solder ball at a location lower than a topmost location of the dielectric layer, the interface between the printed sealing structure and the dielectric layer has a rounded corner, and when viewed from above, the printed sealing structure resembles an annular pattern with a perimeter formed of a plurality of circular arcs and a plurality of discontinuities in curvature where the circular arcs meet.