Smartphone Screens: Understanding Their Structure and Damage Assessment


In the fast-paced world of smartphones, the screen is undoubtedly one of the most vulnerable components. It often becomes a victim of accidental drops, leaving users frustrated and in need of repairs. Surprisingly, some individuals manage to continue using their devices even with a shattered screen, while others face touch sensitivity issues despite their seemingly intact screens. So, what’s the reason behind these contrasting scenarios? Let’s delve into a comprehensive explanation.

Understanding the Composition of Smartphone Screens

Modern smartphone screens consist of two main parts: the inner screen and the outer screen. These two components vary significantly in terms of replacement costs due to differences in functionality and manufacturing processes.

  1. Inner Screen: The inner screen is responsible for both display and touch functionality, which is why replacing it tends to be expensive. It encompasses the display and touch sensors, commonly referred to as the screen assembly. The intricate manufacturing techniques involved in producing the inner screen contribute to its higher repair costs.
  2. Outer Screen: On the other hand, the outer screen acts as a protective layer, commonly made of glass. Its primary function is to safeguard the inner screen assembly. Since the outer screen is a simple glass cover without touch or display capabilities, its replacement cost is significantly lower than that of the inner screen.

Deconstructing Smartphone Screens

Now, let’s examine the typical structure of modern smartphones, which usually comprise four layers stacked on top of each other, from top to bottom:

  1. Cover Glass: This layer serves as a protective shield for the touch sensors and other components located beneath it.
  2. Touch Sensor: As the name suggests, the touch sensor enables users to interact with the screen by registering their touch inputs.
  3. Front Panel: The front panel houses the display and can also accommodate additional components such as filters to generate the various images seen on the smartphone screen.
  4. Backplate: The backplate plays a crucial role in supporting the screen. It contains millions of thin-film transistors necessary for the functioning of the screen.

Determining Screen Damage: Inner vs. Outer Screen

When our smartphone screens suffer damage, two common scenarios arise outer screen damage and combined inner and outer screen damage. To avoid being deceived or misled during repairs, it’s essential to accurately assess whether only the outer screen is damaged or both the inner and outer screens require attention.

  1. Touch Sensitivity: In the case of outer screen damage, the touchscreen may become unresponsive or less sensitive to touch inputs.
  2. Visual Inspection: A simple visual examination can often reveal signs of screen damage. Look for any display abnormalities such as colored blocks or water-like ripples on the screen surface.

To summarize, if touch sensitivity is compromised and there are no visual abnormalities, it’s likely that only the outer screen is damaged. Conversely, if touch inputs are unaffected but the screen displays colored blocks, ripples, or other anomalies, it suggests damage to the inner screen.

  1. Advanced Assessment: As a final measure, you can use strong light to illuminate the screen. This technique can help differentiate between the inner and outer screens. Under bright light, visible cracks solely on the outer surface indicate outer screen damage. However, if you notice cracks on both the inner and outer layers, it signifies damage to both screens.


In conclusion, smartphone screens consist of an inner screen assembly responsible for touch and display functionality, while the outer screen acts as a protective cover.


Leave a Reply

Your email address will not be published. Required fields are marked *

Ask For A Quick Quote

We will contact you within 1 working day, please pay attention to the email with the suffix “”

All Products

35% off

You can rely on us to provide you with up-to-date information and advice.