Were the edges on the pads tapered?
If not, take them off & use a coarse file to taper the leading & trailing edges on a 45 degree angle.
Squealing is normally caused by the pads vibrating ( a very small amount ) in the calipers.
I usually apply a compound called " Disc Brake Quiet " to the back of the pads.
It's kind of a gummy substance, that semi-dries within a few minutes, before you install the pads.
There is also a spray you can buy,which is sprayed on the contact surface of the pads, to reduce/eliminate pad squeal.
