Aligning bumps in fan-out packaging process

A method comprising:

• forming a plurality of metal pads over a carrier;
• bonding first conductive pillars of a first package component and second conductive pillars of a second package component to the plurality of metal pads;
• dispensing an underfill underlying the first package component and the second package component;
• encapsulating the first package component and the second package component in an encapsulating material to form a composite wafer;
• de-bonding the composite wafer from the carrier;
• and
• performing a first planarization on the first package component and the second package component, the underfill, and the encapsulating material to remove the plurality of metal pads.

A package comprising:

• a first package component and a second package component;
• an encapsulating material encapsulating the first package component and the second package component therein;
• a dielectric layer over and contacting the encapsulating material;
• an underfill comprising:
• a first portion between the first package component and the dielectric layer, wherein first conductive pillars of the first package component are in the underfill, and upper portion of the underfill are wider than lower portions of the underfill;
• and
• a second portion between the second package component and the dielectric layer, wherein second conductive pillars of the second package component are in the underfill;
• and
• redistribution lines extending into the dielectric layer to contact the first conductive pillars and the second conductive pillars.