Package with Tilted Interface between Device Die and Encapsulating Material

A package comprising:

• a device die comprising:
• a substrate;
• and
• a sidewall with a tilted portion neither parallel to nor perpendicular to a bottom surface of the substrate;
• an encapsulating material encapsulating the device die therein, wherein the tilted portion of the sidewall is in contact with the encapsulating material;
• a metal post penetrating through the encapsulating material;
• and
• redistribution lines over and electrically coupling to the metal post and the device die.

A package comprising:

• a device die comprising:
• a semiconductor substrate;
• an interconnect structure over the semiconductor substrate;
• a metal pillar over and electrically coupled to the interconnect structure;
• and
• a polymer layer encircling the metal pillar, wherein the polymer layer has a tilted sidewall neither parallel to nor perpendicular to a major bottom surface of the semiconductor substrate;
• an encapsulating material encapsulating the device die therein;
• and
• redistribution lines over and electrically coupling to the metal pillar.

A package comprising:

• a device die comprising:
• a substrate;
• dielectric layers over the substrate, wherein top layers of the dielectric layers have a curved sidewall;
• and
• conductive features in the dielectric layers;
• an encapsulating material encapsulating the device die therein, wherein the curved sidewall is in contact with the encapsulating material;
• and
• redistribution lines over and electrically coupling to the device die.