Package structure and manufacturing method thereof

A package structure, comprising

• a device chip;
• a MEMS die disposed over and electrically connected to the device chip, the MEMS die comprising:
• a substrate having a plurality of cavities;
• and
• a conductive layer disposed within and conformally covering each of the cavities;
• a cap structure disposed on and coupled to the MEMS die, the cap structure comprising:
• a base substrate having a plurality of first protrusions and a plurality of second protrusions, the second protrusions are located between two adjacent first protrusions, each of the first protrusions comprises a first portion and a second portion, the second portion connects the first portion and the base substrate, and the first portion is inserted into the corresponding cavity;
• and
• a bonding layer covering the first portion;
• and
• an eutectic bonding layer located between the conductive layer and the boding layer in the cavities.

A method of manufacturing a package structure, comprising:

• providing a device wafer;
• providing a MEMS wafer over the device wafer;
• bonding the MEMS wafer with the device wafer;
• forming a plurality of cavities in a substrate of the MEMS wafer and forming a conductive layer over the substrate of the MEMS wafer and in the cavities;
• providing a cap wafer;
• forming a plurality of seal rings in the cap wafer and forming a bonding layer partially coveting the plurality of seal rings;
• bonding the plurality of seal rings of the cap wafer with the plurality of cavities of the MEMS wafer through eutectic bonding of the bonding layer on the plurality of seal rings and the conductive layer within the plurality of cavities;
• and
• dicing the device wafer, the MEMS wafer, and the cap wafer to form a package structure.