As illustrated in FIG. 10, the blade 315 cuts into the dicing region 300 from a side of the semiconductor packages 1100 opposite the openings 311/313. In other words, the blade 315 starts cutting into the semiconductor structure shown in FIG. 10 from the upper surfaces of the bottom packages proximate the backsides of the dies 120. As the blade 315 travels toward the redistribution structure 140′, besides the remaining portion 140R of the redistribution structure 140′, the blade 315 does not contact the redistribution structure 140′ due to the openings 311/313 isolating the blade 315 from the redistribution structure 140′. As a result, cracking and/or delamination of the redistribution structure 140′ is avoided or reduced.

Although not shown, the pre-cut process and the dicing process illustrated in FIGS. 7-10 may be performed in other dicing regions, e.g., dicing regions between the PoP packages 500A/500B and other neighboring PoP packages (not shown). After the dicing process is finished, a plurality of individual PoP packages, such as the PoP package 500 illustrated in FIG. 11, are formed.