Singulation of integrated circuit package substrates with glass cores

A system comprising:

• an integrated circuit (IC) substrate comprising:
• a glass core having a first surface, a second surface opposite the first surface, and a sidewall between the first surface and the second surface;
• a build-up layer on at least the first surface;
• a plurality of first regions on the sidewall, wherein each first region comprises a cavity in the sidewall, wherein the cavity spans a first distance in a first direction from the first surface toward the second surface;
• and
• at least one second region on the sidewall that includes a chipped portion or a portion containing a crack, wherein the at least one second region is outside of the first regions.

A method comprising:

• receiving a glass substrate comprising a first surface and a second surface opposite the first surface;
• altering a microstructure of the glass substrate by treating a plurality of regions within singulation streets on the first surface with a laser, wherein a plurality of portions of the glass substrate are demarcated by the singulation streets;
• forming a first perforation in each of the plurality of regions by removing glass substrate material using a wet etch process on the first surface;
• and
• separating the glass substrate into the plurality of portions by performing mechanical sawing operations along lines coinciding with the plurality of regions.