LCD Shielding (EMI/ESD)

LCD IPS technology with in-cell touch functionality gained momentum in high-end smartphone displays. Clevios™ shielding layers bring their manufacturing processses and optical properties to the next level.

LCD Shielding

Although LCD is a mature technology, there is ongoing and constant development to improve its performance. The adoption of IPS (in-plane switching) technology in modern displays marked an important milestone and brought about improved color, contrast, and viewing angle.

Difficult sputtering

However, IPS LCD technology is prone to static charges and ESD (electrostatic discharge), and shielding layers are needed to protect the displays. Typically, a thin sputtered layer of ITO (indium tin oxide) on the color filter glass would suffice. However, ITO sputtering becomes increasingly difficult as display glasses are highly slimmed and substrate sizes grow larger. Wet coating such as slot-die or spray-coating do clearly outplay sputtering and provide the additional benefits of being faster throughput, less downtime and higher material yield.

Advanced formulations

Heraeus offers advanced conductive polymer formulations, Clevios™ F ELO, optimized for optical quality coatings on display glass. The product can be applied by an economical wet-coating process on the displays as a shielding layer. Excellent optical properties, a well adjustable and uniform sheet resistance, and high hardness and durability are some of the key features.

Controlling light reflection

When it comes to light reflection losses, Clevios™ clearly outperforms ITO due to its lower refractive index of approximately 1.5, matching well with glass. Compared to ITO coatings, light reflection is reduced by up to 50%. This can help improve display contrast such as in automotive interior applications where light reflection is a challenge.

LCD Shielding (EMI/ESD)

In-cell touch and TDDI

A major trend in smartphone displays is the adoption of in-cell touch technology. This is due to the demand for thinner and brighter displays as well as the integration of touch and display driver (TDDI) in a single chip.

ITO doesn’t work as a shielding layer for in-cell touch as it is too conductive and thus would also be shielding the sensing of touch.

Shield and protect

Clevios™ conductive polymers are perfectly suited to this because their conductivity can be tuned over such a broad range and a sheet resistance of 10E7 – 10E9 Ohm/sq so that the shielding layer works well for both display and touch functions. Clevios™ F EHO is the right product to shield and protect your displays.

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