Manufacturing Micro LED Displays (μLED)

LCD Manufacturing Equipment
Crystec Technology Trading GmbH

Machines for manufacturing MicroLED / μLED

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:

1)ACF (Anisotropic conductive film) Pre Lamination

Before mounting the LED chips, the substrate has to be prepared.

2) Chip Mounting

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.

3) ACF (Anisotropic conductive film) Lamination

By heat and pressure the μLED chips are attached on the anisotropic foil.

ACF Lamination Shindo Eng. Lab.

Application:

  • Micro LED
  • Flexible Displays
  • Semiconductor back film Lamination
  • - Construction vacuum glass

Specification:

  • - Heater: Cartridge Heater
  • Internal coolant: SUS stainless steel pipes
  • Optical Sensor, double safety device
  • Max. temperature: 200 °C
  • Max. compressor: 20 kgf/cm2

micro LED Vacuum Press

4) Plasma

At Step 4. plasma cleaning is necessary.

5) TC Bonding

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.

6) UV Molding

7) Under-Fill-Machine

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.

Thermo compression
TCB with post applied Under Fill

8) Optical film Lamination

An optical film is laminated using a corresponding machine.

9) Autoclave

After that an Autoclave is used to get rid of micro air bubbles that can build up visible bubbles later.