What makes tempered glass has a perfectly adsorption of it？

It is AB glue.Simply, just as its named 'AB glue', have A, B side . The glue on 'A' side is OCA, usually called optical plastic. This kind of glue widely used in TP(Touchpad) and optical vision industry.It has a high light  transmittance.Viscosity and other characteristics.

The B is Silica gel,this glue has a great feature, it will automatically exclude bubbles when Smooth surface with the surface of the object to paste . It  is mankes contact surfaces become vacuum state, accordingly to achieve perfect fit. 

While useing, you just need to Align the phone screen.Try not to paste distortion.Then gently push down slightly press with a little bit of force. Then it's done.