Protecting T-contacts of chip scale packages from moisture

A method comprising:

• providing a package structure comprising:
• a device wafer comprising a plurality of device dies, and scribe lines between the device dies;
• a carrier wafer over and bonded to a top side of the device wafer;
• a glass wafer under the device wafer;
• and
• dams bonding a bottom side of the device wafer to the glass wafer, wherein the dams overlap scribe lines, and do not overlap center regions of the plurality of device dies;
• forming a first trench in the carrier wafer and the device wafer until contacts pads in the device wafer are exposed;
• forming a first dielectric coating to extend into the first trench;
• performing a first die-saw to saw the first dielectric coating and the scribe lines of the device wafer, wherein side edges of the contact pads are exposed after the first die-saw;
• forming metal leads over remaining portions of the first dielectric coating and contacting the side edges of the contact pads;
• performing a pre-cut to cut connecting portions of metal leads, wherein each of the connecting portions interconnects two of the metal leads;
• forming a second dielectric coating to cover the metal leads;
• and
• performing a second die-saw to separate the package structure into individual pieces, wherein no remaining portions of the metal leads in the individual pieces are exposed to open air.

A device comprising:

• a device die comprising integrated circuits and a contact pad;
• a carrier die over and bonded to a top side of the device die;
• a first dielectric coating on a sidewall of the carrier die;
• a metal lead over and contacting the first dielectric coating, wherein the metal lead extends vertically lower than a bottom surface of the contact pad and contacts a side edge of the contact pad to form a T-contact, and wherein the metal lead extends to directly over the carrier die and the device die;
• and
• a second dielectric coating over and contacting the metal lead, wherein all edges of the metal lead are covered, and wherein no edge of the metal lead is exposed through the second dielectric coating.