Organic light emission diode (OLED) display device has become a very important display technology in the field of flat panel display, due to its advantages of small thickness, light weight, wide viewing angle, good capability of actively emitting light, continuous and adjustable wavelength of the emitted light, low cost, fast response speed, small energy consumption, wide range of working temperature, simple production process, high light emission efficiency, flexible display, and the like.
Components such as water vapor and oxygen in the air have very large influence on the service life of an OLED in the OLED display device. A cathode of the OLED is generally formed by a metal material such as aluminum, magnesium, calcium, etc., and such metal material has relatively active chemical properties and very easily reacts with the water vapor and oxygen. In addition, the water vapor and oxygen easily has a chemical reaction with an organic light emission layer of the OLED. The above reactions cause a failure of the OLED. Therefore, the OLED display device needs to be effectively encapsulated, such that respective functional layers of the OLED are fully separated from the components such as water vapor and oxygen in the air.
Encapsulation methods for the OLED display device generally include two types of substrate encapsulation and thin film encapsulation (TFE). The substrate encapsulation refers to that an adhesive is filled between a display substrate having the OLED and an encapsulation substrate, an airtight space is formed between the display substrate and the encapsulation substrate after the adhesive is cured, and thereby the encapsulation effect is achieved. The thin film encapsulation refers to that an organic thin film encapsulation layer covers the surface of the OLED, such that it is difficult for the water vapor and oxygen to enter the OLED.