original LCD for Z3 and z3 compact is thinner than china LCD thats why it can't be "normally" mounted in original frame. Digitizer must be glued to frame in middle frame also. IN the beginning, also sony realized if they will use only glue tape for z3 frame it will not hold like in z/z1/z2 model so they decide to use some kind of silicone glue and glue this digiitzer to frame with this glue not with tape. we must find what kind of glue sony used for frame or you can buy lcd+digi in frame which will be also glued by china workers. Sony for Z3 lcd made black thin protection foil to prevent glue to run into LCD. I start post about it in XDA forum, Z3 Q&A maybe somebody will show some light on it.