Overview

A non-uniform air gap or bending of the glass with the laminated touch sensor can negatively impact touch performance and accuracy.

Symptoms

If the air gap is inconsistent or the glass is bending, you may observe:

• False or ghost touches

• Areas with reduced or no touch response

• Inconsistent touch sensitivity across the screen

• Poor edge performance or unstable touch near borders
  

Example: A large, heavy glass touch panel laid horizontally over a display may bend. If the center sags too close to the display, it can create a large circular dead zone where touch input is not detected.

Causes

These issues typically occur when:

• The air gap thickness varies across the display

• The glass is not properly supported or fixed

• Excessive pressure or weight causes the glass to bend or flex

• Mounting materials are uneven or incorrectly applied

Uneven spacing between the sensor and display affects capacitance and disrupts touch and EMI signal interpretation resulting in poor performance.

Recommended Solution

• Ensure the air gap is uniform across the entire surface

• Use consistent, high-quality double-sided bonding tape around the bezel

• Avoid any mechanical stress or bending of the glass

• Verify installation with temporary spacers before final mounting
  

1. If not possible to completely prevent large glass panes from bending, the air gap may need to be increased.
   

Summary

For optimal touch performance, the glass and sensor must remain flat and evenly spaced from the display. Any inconsistency in the air gap or structural bending can lead to unreliable or inaccurate touch behavior.