Preface
A capacitive touchscreen is one of the essential components in modern smart devices, enabling user-device interaction. The touch lifespan of a capacitive touchscreen refers to the maximum number of touches it can withstand during usage. It is an important indicator for evaluating its lifespan and performance, as it significantly impacts user experience and device stability. However, the touch lifespan of a capacitive touchscreen is theoretically limited and influenced by various factors such as materials, manufacturing processes, usage environment, frequency of use, and touch intensity. This report aims to assess the touch lifespan of a capacitive touchscreen.
I. Analysis of Capacitive Touchscreen Principles
A capacitive touchscreen is an electronic device that senses changes in capacitance caused by human touch or other conductive materials on the screen to determine the touch position, as shown in Figure 1. Its advantages include the ability to operate in various environments such as low temperature, high temperature, high humidity, and even when the screen surface is wet or oily. The core components of a touchscreen generally include control boards, flexible ribbons, and touchscreen glass. From the principle of capacitive touchscreens, it is evident that the touch lifespan is related to the durability of the touchscreen glass when the screen is touched or swiped with a finger.
II. Capacitive Touchscreen Structure
The mainstream structure of a capacitive touchscreen usually includes G+G, G+F, and G+F+F. Taking G+G as an example, it consists of a cover glass and a sensor glass. The upper layer is a protective glass designed for finger touch, while the lower layer is a sensor glass used for touch position sensing, as shown in Figure 2. Tempered glass is commonly used as the protective glass, with a surface hardness of ≥6H, significantly enhancing the protection ability of the capacitive touchscreen. When a user touches the screen with a finger or stylus, the deformation impact on the surface of the capacitive touchscreen is minimal, enabling the touchscreen to have a longer touch lifespan.
III. Comparison with Other Types of Touchscreens
Taking resistive touchscreens as an example, they primarily rely on pressure sensitivity for control. The upper layer is a hardened and scratch-resistant plastic layer that is directly touched, while the layer beneath it consists of a conductive layer. The lower layer is made of glass or organic glass and is coated with a transparent conductive layer. When a user touches the screen with a finger or an object, pressure is applied to deform the upper plastic layer, causing the two conductive layers to make contact and changing the resistance. The controller then determines the coordinates of the touch point and performs corresponding operations based on the specific resistance changes.
Resistive touchscreens generally have a surface hardness of ≥3H. In comparison, capacitive touchscreens have a higher surface hardness of ≥6H, indicating better durability in terms of touch lifespan, scratch resistance, and wear resistance. Capacitive touchscreens only require detection of changes in capacitance to register touches, while resistive screens require pressure to generate touch signals. Overall, capacitive touchscreens have a longer touch lifespan than resistive screens due to the absence of any mechanical deformation in their components. Resistive touchscreens typically have a touch lifespan of around 10 million touches, while capacitive touchscreens can exceed 30 million touches.
IV. Usage Environment
The touch lifespan of a capacitive touchscreen is influenced by the usage environment. Outdoor environments, high temperatures, and high humidity can accelerate the degradation of a capacitive touchscreen's lifespan. This is because operating in extreme environments increases hardware aging and corrosion, resulting in greater damage to the capacitive touchscreen. It is recommended to use capacitive touchscreens within the temperature range of 0°C to 35°C and humidity range of 0% to 60% to ensure optimal touch lifespan.
V. Industry Standards
According to the International Electrotechnical Commission (IEC) standards, the touch lifespan of a capacitive touchscreen should reach at least 50,000 touches. This standard is based on real-world usage scenarios to ensure that devices do not experience frequent touchscreen failures during usage. Capacitive touchscreens have been widely applied in fields such as mobile devices, medical equipment, and industrial devices, with touch lifespans exceeding tens of millions of touches.
VI. Conclusion
This report analyzes the touch lifespan of capacitive touchscreens by discussing their principles, comparing them with resistive screens, considering usage environments, and examining industry standards. Our capacitive touchscreens have a long touch lifespan, exceeding 30 million touches.