Every day, TFT LCD touch screens are showing up in more and more products, from consumer electronics to industrial and medical equipment. Although there are well-established design ideas for the usage of TFT touch screens, engineering and product design teams frequently encounter challenging issues. A lot of "hair-pulling" may be avoided by using TFT LCD touch panel best practices.
Make sure the product enclosure and the TFT LCD screen have appropriate space (and a cushion) between them.
Make sure the TFT LCD module is not bent, warped, or twisted before attaching it.
The bezel window needs to be larger (>0.5mm) than the active area of the capacitive touch panel.
Bezel and CTP surface should be separated by an insulated gasket (0.5–1mm).
It is advised to use an additional back support bracket for thin type TFT LCD displays.
The TFT LCD display is attached to the countersink area using double-sided glue.
Between the product housing and the LCD cover lens, a space of at least 0.3 millimeters is advised.
When necessary, a backside support with gasket should be employed (for instance, with a TFT touch screen devoid of a mounding structure).
Engineers should double-check the CTP specifications about the allowable material and thickness if more cover lenses are required.
There must be a 0.2–0.3mm space between the cover lens and the TFT LCD screen.
The cover lens window needs to be larger (>0.5mm) than the active area of the TFT touch screen.
Between the bezel and the TFT LCD touch screen surface, there has to be a 0.2–0.3mm space.
To prevent users from pushing the RTP ITO Film connection region, the bezel shall cover the TFT LCD screen view area by at least 0.5mm (B).
between the wall of the bezel and the side of the TFT touch display, leave a 0.2–0.3mm space.
A number of problems may occur if the ground approach used for a device with a TFT touch display is not carried out in accordance with best practices. Typical difficulties with grounding include:
A lack of noise immunity when interference adversely impacts the operation of devices
Long-term drift, when changes in voltage gradually impair the performance of the display
Maintaining short ground connections and minimizing impedance are often the two main issues. This criterion is especially important for the ground connections between the touch controller and the display casing. Though less significant than length, the ground connection's diameter still has an impact.
Avoiding ground loops is a crucial consideration for grounding design. By using a star topology for ground distribution, it is possible to prevent a potential from forming between two places that are both supposed to be at ground level.
Any floating conductive objects close to a touch sensor can disrupt touch functionality. The touch controller should thus have the same ground potential for all of them.
You must adhere to recommended practices, such as physical device assembly and grounding design, to overcome such problems. Engineers will also face a variety of other difficulties, including those related to durability, sleek design, and other issues. It's crucial to collaborate with a hardware vendor like Kelai who can offer guidance at every stage of your road to market. Kelai provides you with that advice and the capacity to shorten your time to market thanks to its broad base of knowledge and 20+ years of experience in the TFT LCD business.