How Glove Boxes Ensure the Stability of Printed OLED Inks?

As BOE, TCL Huaxing accelerate the layout of printed OLED production lines, solution-based fabrication technology is regarded as an important route for next-generation display manufacturing due to its advantages of high material utilization and large-area film formation. In 2026, several enterprises have built G4.5 or G6 pilot lines to carry out printing verification of red, green and blue inks. However, although the solution method does not require vacuum evaporation, its requirements for the operating environment are not reduced. Organic semiconductor precursors (such as small-molecule fluorescent materials, polymeric emitters, and perovskite quantum dots for new light-emitting devices) are highly susceptible to degradation or aggregation under trace amounts of water and oxygen, resulting in reduced luminous efficiency and poor batch repeatability. Therefore, the entire process from ink preparation, filtration to storage before substrate coating must still be carried out in a high-purity inert atmosphere.

Solution Process ≠ Low Environmental Requirements: Water and Oxygen Sensitivity Underestimated

Contrary to traditional understanding, the functional materials used in printed OLEDs are no less sensitive to water and oxygen than evaporation materials. For example, perovskite quantum dots decompose rapidly in the presence of water and lose their luminescent properties. Even if the solvent itself has been dehydrated, exposure to the ambient atmosphere during preparation, stirring and ultrasonic dispersion will introduce impurities such as water and oxygen.

Therefore, the "wet process" of printed OLEDs also requires strict inert atmosphere control to ensure the chemical stability of inks and film uniformity.

To meet this demand, Mikrouna ADVANCED series glove boxes can integrate a solvent purification system and an ink operation module to build a fully enclosed workflow from raw materials to film formation:

First, Solvent Purification Ensures Basic Cleanliness

The glove box is equipped with an organic solvent purification device, which can perform online dehydration and deoxygenation of solvents such as toluene and chlorobenzene, outputting high-purity solvents with water and oxygen content < 1 ppm, avoiding risks caused by batch differences of purchased solvents.

Second, High Sealing Ensures Long-Term Atmosphere Stability

The cabinet adopts three-sided integrated bending plus argon arc continuous laser welding, with welds inspected by non-destructive testing.

Matched with an integral annular seamless O-ring and an 8 mm thick tempered glass window, the overall leakage rate is < 0.0006 vol%/h.

Third, Seamless Connection with Downstream Equipment

Through standard flange interfaces, it can be directly connected with inkjet printheads, slot die coaters, annealing chambers, etc. Inks are kept away from the atmosphere from preparation to coating, eliminating contamination during transfer.

The control system adopts Siemens S7 PLC, supporting real-time monitoring and data recording to meet traceability requirements in R&D and pilot stages. Compared with imported equipment, Mikrouna (Shanghai) Industrial Intelligent Technology Co., Ltd. has obvious advantages in customization flexibility, delivery cycle and local service response, and has served many new display R&D institutions.

At the critical stage when printed OLEDs move toward mass production, environmental control is no longer an "option" but a "necessity" that determines material performance and process repeatability. As the first line of defense for ink preparation, high-purity glove boxes are providing underlying equipment support for the independence and controllability of China’s new display industry chain.