Hi,
For a best result you have to use adhesive sticker prepared for the model:
https://www.google.com.cy/imgres?imgurl=http://thumbs.ebaystatic.com/images/g/C-IAAOSwYHxWMewm/s-l225.jpg&imgrefurl=http://www.ebay.co.uk/sch/Adhesive-Mobile-Parts-for-Sony-Xperia-Z3-Compact/43304/bn_463237/i.html&h=225&w=225&tbnid=ikoFVPaVBwt_gM:&docid=jdHP8xQTPmlpWM&ei=7VXNVp65E8yMarK2obAC&tbm=isch&ved=0ahUKEwje45Hj6o_LAhVMhhoKHTJbCCYQMwgjKAkwCQ
If the tape you used is of good quality, probably frame is not cleaned well. You need to use an isopropyl alcohol to clean the frame.
Often, when the spare part is not of good quality or if there is hit, deformation of the frame, the screen does not fit well to the frame.
Before I put the adhesive, I try the screen to the frame. From time to time I use a sharp screwdriver to "sculpting" the frame.
Regards.