Electroluminescent backlight

Keytouch designs and manufactures front panels, membrane switches, and electro mechanical operating panels with embedded electroluminescent backlight (EL-film).

Advantages of electroluminescent backlight:

  • Low thickness
  • Light is distributed 100% evenly over large surfaces
  • No heat dissipation
  • Light weight
  • Flexible
  • Available in White and Green
  • Dimming available
  • Luminary buttons, texts, frames, logos etc.

EL-film structure

EL-film is printed in layers onto a polyester surface composed of a layer of custom-made phosphorous situated between two electrodes. When AC-voltage is connected, an electric field is created which ignites the phosphorous particles. Operation life of the EL-film depends on on-time and inverter voltage/frequency. Optimal duration is best obtained by dimming the light, installing a light sensor to switch it off when not needed, or by time-limited activation.

Since 1997, the production process related to EL-film has undergone constant evolution. Our expertise on the area currently includes technical printing processes, chemical processes, graphic design and electronic solutions.


Keytouch can provide an inverter to the el-film, which can also control dimming of 0-100%. The inverter circuit has integrated filter components, which makes the el-film solution pass both Maritime and Military EMC requirements.


A shield layer can be embedded in the EL-film construction, to prevent crosstalk from the EL-film to nearby pushbuttons.

Technical Data

Power consumption


mA/cm2 @ 5V



Luminous intensity



Serial reproducibility



Wear life, 20°C / 50% RH

> 50.000



>= 0.175


Storage temperature at 30% RH

-40 – +100


Application temperature at 30% RH

-40 – +85


Data sheet EL-film