Comparison of Three Packaging Technologies

1. COG (Chip On Glass): This is one of the most traditional packaging methods, with low technical barriers and low costs, and is the most commonly used technology for screens. From the English version, it can also be seen that this packaging method involves placing IC chips and FPC cables on the back glass of the screen. However, due to the IC chip being located directly below the LCD, a considerable amount of screen space is squeezed, inevitably resulting in a "chin".

2. COF (Chip On Film): Essentially, it is an upgraded version of COG and a key factor in the current screen transformation. The main principle is to place the display driver IC chip into a flexible FPC cable, and then fold it under the screen using the characteristics of the FPC itself. Specifically, through hot pressing, the Gold Bump of the IC chip and the Inner Lead on the flexible substrate circuit will be bonded together. Due to the release of space occupied by IC chips, the lower frame width can generally be reduced by at least 1.5 millimeters.

3. COP (Chip On Pi): It belongs to the process with the most reduced borders, but it should be emphasized that the premise of this process is the application of flexible OLED screens, which utilize the bending characteristics of flexible OLEDs to bend all cables and ICs below the screen. Of course, OLED is also divided into two types: hard screens and flexible screens. To use this technology, a combination of COP packaging technology and flexible OLED must be used. However, this technology still has the disadvantages of high cost and low yield rate.

After introducing the technical foundations of COG, COF, and COP, let's take a look at the practical application of COP technology on Samsung S8. This phone adopts innovative COP screen packaging technology, which allows the screen edges to bend without physical limitations, achieving a nearly borderless visual effect. This technology not only enhances the aesthetic appearance of mobile phones, but also brings them a wider display space.