squeaky brakes on 2000 Cadillac DeVille

My brakes always squeak, even though they have been replaced several times!! What could be the reason for this??

Asked by for the 2000 Cadillac DeVille
Usually its because of the high metal content of the pads, next time have ceramic pads installed as they are very quiet.
2 answers
The quality of the brakes or the rotors