Manufacturing Micro LED Displays (μLED)
LCD Manufacturing Equipment
Micro LED Displays (also μLED, MikroLED, MicroLED, MLED, Micro LED) are based on a screen technologyon of small light emitting diodes in the μm range. Such as OLED Technology no backlight is needed. In fact, each diode emits light itself. Colors are generated using red, blue and green LEDs simultaneously. While OLED technology is based on organic LEDs, μLEDs are made of semiconductor materials like conventional LEDs. Therefore, nearly all advantages of OLED technology remain. Additionally, semiconductor based LEDs produce higher light yield, significantly higher life expectancy and age at the same speed regardless of the color. So there is no burning out effect like in OLED technology. (Color distortion over a long period of time)
For manufacturing such displays, glass or foil is used as a substrate.
On this substrate μLEDs are mounted using thin-film technology (over 1 million micro LEDs per display)
After that different protection layers are applied.
Crystec Technology is glad to be of service providing machines for the single process steps.
Precisely following steps are necessary for manufacturing MicroLED Displays:
Before mounting the LED chips, the substrate has to be prepared.
After that the chips are mounted. Therefore, normally a so-called pick and place robot or Laser Lift Off technic (LLO) are used. Before mounting, the chips can be attached in a block. The 20 μm LED chips are used for TVs and mobile phones, 100 μm LED chips for TVs, and 300 μm LED chips for outdoor billboards.
By heat and pressure the μLED chips are attached on the anisotropic foil.
|ACF Lamination Shindo Eng. Lab.|
At Step 4. plasma cleaning is necessary.
After that a Thermo compression bonding (TC) step follows. A so-called FOF (Foil on Foil) bonder is required for this. This machine connects the FPCB (Flexible Printed Circuit Board) to the display. These are fully automated machines with variable pressure and temperature control. Cycle times of 6 seconds are possible.
Before attaching the Chip-Blocks, glue has to be applied on TFT Glass. This process takes place in a under fill machine. Alternatively, the under fill process can take place before TC bonding.
An optical film is laminated using a corresponding machine.
After that an Autoclave is used to get rid of micro air bubbles that can build up visible bubbles later.