How should the Back Glass Tape be attached on the Galaxy S9/S9+?

• A. Attach the inner tape first, then align with guide holes
• B. Attach the outer tape on the rear assembly using guide holes to align tape
• C. Stick tape without alignment
• D. Align by eye and press hard

Answer: (B)

Precise edge alignment of the back glass tape is essential to ensure the rear panel sits flush and seals properly. On the Galaxy S9/S9+, the correct method is to attach the outer tape on the rear assembly and use the guide holes to align it. Those guide holes are there to position the tape exactly where it needs to be, matching the chassis and clearances around openings and components. When you align with these holes, the tape sits evenly along the edges and doesn’t overlap into areas it shouldn’t cover, which helps the glass install cleanly and prevents gaps or misfit later.

If you try to align by eye or go straight in without using the guide holes, the tape can end up misaligned, which can cause improper adhesion, interference with other parts, or a nonflush finish. Attaching inner tape first isn’t the standard practice for this step, since the outer tape alignment is what guarantees the correct placement relative to the chassis features. After the outer tape is properly aligned with the guide holes, press firmly to secure it and then complete the assembly.