The high-temperature stability of a touch panel is one of the most important indicators of its performance evaluation, directly affecting its reliability, service life and user experience in a high-temperature environment.
1. The impact of high temperature on touch display:
(1) Material performance degradation
High temperatures may cause the conductive material of the touch screen (e.g. ITO film) to increase in resistivity, reducing touch sensitivity.
Optical Colors Adhesive (OCA) or adhesives may soften at high temperatures, resulting in delamination or bubbles, affecting the display.
Thermal expansion of glass or plastic substrates may occur at high temperatures, resulting in screen distortion or breakage.
(2) Decline in touch performance
In a high-temperature environment, the response speed of the touch screen may slow down. This is because high temperatures cause the internal circuitry of the touch screen to work at a reduced speed, which affects the smoothness of the touch operation. Especially in application scenarios that require fast response, such as games, industrial control, etc., the decline in touch response speed will seriously affect the user experience and equipment performance.
(3) Display deterioration
Liquid crystal material (LCD) response time becomes longer at higher temperatures, which may lead to ghosting or display blurring.
Organic light-emitting materials (OLEDs) have a shorter lifespan at high temperatures, which may result in screen burn or brightness degradation.
(4) Shortened life span
High temperature accelerates the aging of electronic components, shortening the life of the touch screen. In particular, touch panels that have been operating in a high-temperature environment for a long time are prone to overheating of their internal components, leading to premature damage. For example, when used for a long time at high temperatures, components such as backlight tubes and driver circuits of the touch screen may fail due to overheating.
(5) False touch rate increases
As high temperatures affect the sensor material and signal processing circuitry of the touch screen, the touch operation is more susceptible to external interference, which leads to an increase in the false touch rate. This is very unfavorable for application scenarios that require high-precision touch operations.
2. Technical measures to improve high temperature stability:
(1) Material selection
Use high temperature resistant liquid crystal materials and touch sensor materials.
Use high-temperature resistant optical glue and adhesive to enhance material stability.
Select substrate materials with low coefficient of thermal expansion (e.g. Corning Gorilla Glass).
(2) Heat dissipation design
Optimize the heat dissipation structure by adding heat sinks or graphene heat dissipation layers.
Adopt bezel materials with better thermal conductivity (e.g. aluminum alloy).
Apply thermal coating on the back of the screen to improve heat dissipation efficiency.
(3) Circuit protection
The device is designed with an over-temperature protection circuit, which automatically reduces power consumption or shuts down some functions when the temperature is too high.
Optimize the touch chip algorithm to reduce the impact of temperature on touch accuracy.
3. Industry applications and cases.
Industrial field: Industrial touch panels need to operate stably in high-temperature workshops (e.g. metallurgy, glass manufacturing), and usually require operating temperatures ranging from -20℃ to 70℃.
Automotive: Automotive touch panels need to pass AEC-Q100 certification to ensure that they can still work properly at high temperatures (e.g. 85℃).
Outdoor equipment: Outdoor advertising machines, self-service terminals, etc. need to be designed for high temperature resistance to prevent overheating caused by direct sunlight.
Future Development Direction
Summary: The high temperature stability of the touch screen needs to be optimized from materials, design, testing and other aspects. With technological advances, the future touch screen will achieve more stable and reliable performance in higher temperature environments.