Semiconductor structure and manufacturing method thereof

A semiconductor structure, comprising:

• a three dimensional stack comprising:
• a first semiconductor die;
• a second semiconductor die electrically connected with the first semiconductor die with a first active bump positioned on a frontside of the second semiconductor die;
• and
• a molding compound between the first semiconductor die and the second semiconductor die;
• wherein a dummy portion of a metal structure being over a surface of the three dimensional stack and contacting a backside of the second semiconductor die, the dummy portion neither being electrically coupled to the first semiconductor die nor to the second semiconductor die;
• a dummy bump connected with the dummy portion of the metal structure, the dummy bump being surrounded by ambient air;
• and
• an active portion of the metal structure over the surface of the three dimensional stack, not contacting the backside of the second semiconductor die, and configured for electrically connecting the three dimensional stack with an external electronic device, wherein the active portion and the dummy portion are in a same level of the metal structure.