Why does the iPhone X have no chin? You'll understand after reading this

Recently, the vivo APEX has been making waves in the tech world, with its advanced design and 98% screen-to-body ratio. However, some careful friends have discovered that the chin of the vivo APEX is very narrow, but still exists. However, the iPhone X released last year really has no chin. How did it do that?

First of all, why do most mobile phones have chins?

Some people say that this is because of the existence of buttons, such as the iPhone's HOME button. Although there is a certain relationship, it is not the most important reason. The real reason why mobile phones have chins is actually because of the packaging method of the screen itself.

What is "encapsulation"?

Simply put, a screen cannot display images by itself after it is produced. If you want the screen to display a specific image, you need a corresponding "control circuit", which we call a "driver IC", which is generally one or more chips, as shown below:

You can see that there is a row of chips under the panel, which are the "driver IC and printed circuit board" marked in red in the picture. It is responsible for receiving the image data to be displayed through the circuit (usually a flexible cable), and then the control panel displays the corresponding color at the corresponding position to form an image.

For mobile phones, although the screen sizes they carry are relatively small, the basic structure will not change, and there must be such a driver IC on one side of the screen.

The process of combining the screen panel and the driver IC to make it a "directly usable" screen is called packaging. The packaging method mentioned above is called COG packaging.

For previous mobile phones, COG packaging is not a problem, after all, they not only have a large chin, but also a high forehead, and there is plenty of space to put these things. For example, the iPhone screen, its driver IC and flexible cable are located at the top of the screen:

This is why the recently popular Xiaomi MIX2, although claiming to be a full-screen phone, still has a chin: the earpiece can be shrunk and hidden, the buttons can be virtual, but the screen's driver IC can never be removed.

So, how did the iPhone X get rid of the chin?

In fact, Apple’s solution is very violent, very clever, but very effective:

That's right, it uses an exclusive customized flexible screen, and then bends a part of the lower part of the screen inward, so that the driver IC part is placed on the back of the screen, and it will not take up extra space.

The position marked by the red frame in the above picture is the position of the screen driver IC of iPhone X. In this way, the borders around the screen of iPhone X can be made of the same width.