Got weird tiny spots on my pictures after iPhone repair

Hey there,

i did several replacement jobs on an iphone 5. Everything worked fine so well, but after a recent lightning adapter replacement i did all my "standard-tests" and noticed tiny spots on pictures of the rear camera.

Well, i thought i touched the camera during assembly and those spots are just fat (or something else). I opened the phone again, cleaned the camera and the glass, closed it. Still spots.... Argh! Did this two more times until i took a test picture before and after cleaning.

Result: Spots are always the same on the exact same position. Not possible after cleaning it for a quite long time?! Does anyone know what this is all about?! What could be the reason for the spots?!

Here is a test picture

Help me :/

Best,

Jochen