Package structure, apparatus and forming methods thereof

A package structure, comprising:

• a cover;
• and
• a cell disposed within the cover, the cell comprising:
• a membrane comprising a first membrane subpart, a second membrane subpart and a third membrane subpart, wherein the first membrane subpart and the second membrane subpart are opposite to each other in a top view viewing along a top-view direction, and the third membrane subpart is disposed by a first side of the cell between the first membrane subpart and the second membrane subpart in the top view, such that the first membrane subpart and the second membrane subpart are opposite to each other in a first direction perpendicular to the top-view direction;
• an actuating layer disposed on the first membrane subpart and the second membrane subpart in the top-view direction;
• an anchor structure, wherein the membrane is anchored by the anchor structure;
• and
• a spring connected between the first membrane subpart and the third membrane subpart;
• wherein the first membrane subpart comprises a first anchored edge which is fully or partially connected to the anchor structure for being fully or partially anchored by the anchor structure, and edges of the first membrane subpart other than the first anchored edge are non-anchored;
• wherein the second membrane subpart comprises a second anchored edge which is fully or partially connected to the anchor structure for being fully or partially anchored by the anchor structure, and edges of the second membrane subpart other than the second anchored edge are non-anchored;
• wherein the third membrane subpart is configured to reduce acoustic leakage at the first side of the cell, the third membrane subpart comprises a third anchored edge which is anchored, and edges of the third membrane subpart other than the third anchored edge are non-anchored;
• wherein a first ratio of the membrane is larger than 2, and the first ratio of the membrane is a ratio of a first length of a first side of the membrane to a second length of a second side of the membrane in the top view;
• wherein a first slit is formed between the first membrane subpart and the second membrane subpart;
• wherein the first slit is parallel to the first anchored edge or the second anchored edge;
• wherein a second slit is formed between the first membrane subpart and the third membrane subpart.