Chip package and method for forming a chip package having first and second stack of dummy metal layers surround the sensing region

A chip package, comprising:

• a first chip, comprising:
• a first substrate having a first surface and a second surface opposite the first surface of the first substrate, and having a sensing region adjacent to the first surface of the substrate;
• a first dielectric layer having a first surface and a second surface opposite the first surface of the first dielectric layer, wherein the first surface of the first dielectric layer adjoins the second surface of the first substrate;
• a first dummy structure formed in the first dielectric layer and adjacent to edges of the first dielectric layer, wherein the first dummy structure surrounds the sensing region and comprises:
• a first stack of dummy metal layers and a second stack of dummy metal layers arranged concentrically from the inside to the outside;
• and
• an optical element disposed on the first surface of the first substrate and aligned with the sensing region.