Crystec Technology Trading GmbH

Organic light emitting displays (OLEDs), OLED lights, dye sensitive solar cells (DSSC) and electronic paper displays (EPD or e‑papers) are different products but share a similar construction principle. They all consist of cover sheets (glass or foil), top and bottom electrodes and, in between, some liquid, gel‑type or soft organic layers. Here is a short, simplified description of these units:

Organic light emitting displays (OLEDs) consist of a substrate layer with a transparent conductive coating on which two organic semiconductor layers are deposited. One of these organic layers serves as the emitter layer, the other functions as a hole transport layer (HTL). The cathode is formed by a metallic layer and the cell is closed by a cover glass or cover foil. OLEDs can be built as displays or simply as light sources (OLED light).

Dye sensitive solar cells (DSSC), also called Grätzel cells, are thin‑film solar cells composed of electrodes, a porous high‑surface titanium dioxide layer covered with a molecular dye and an aqueous electrolyte. Light causes emission of electrons from the dye; the titanium dioxide transmits the electron to the transparent anode. The iodine‑containing electrolyte restores the missing electron in the dye. Sunlight induces a current.

Electronic paper displays (EPD or e‑papers) consist of a substrate with a reflective electrode, lithographically formed pixel walls and e‑ink: charged, colored or white pigments suspended in a liquid, together with a transparent top electrode and a cover layer. When voltage is applied the pigments change position and dark or white pixels form. Flexible cover foils are commonly used.

For manufacturing organic light emitting displays (OLEDs), OLED lights, dye sensitive solar cells (DSSC) and electronic paper displays (EPD or e‑papers), similar techniques can be used to assemble the cells. In all cases a lower substrate with a special coating must be joined with an upper glass or foil on which the seal is usually printed or dispensed. The two sheets must be assembled under vacuum to avoid bubble inclusions. The sheets are then pressed together with a controlled force to ensure correct spacing and good contact of the layers. Pressure must not be too high to prevent squeeze‑out of deposited layers or sealing material. The seal is then hardened to create a stable cell; in many cases it is advantageous to cure while the sheets remain pressed with the adjusted force.

Different assembly machines were developed for LCDs, OLEDs, DSSCs and EPDs. Layers are laminated under vacuum and the available machines support 2D applications, 3D applications and roll lamination. The picture below shows equipment from our partner Shindo Eng. Lab. and the three application types with their specifications.

Vacuum lamination equipment for attaching the cover glass and LCD / OLED panel, CPI (Colorless PI) or UTG (Ultra Thin Glass) and OLED panels.

Application:

• Attach Panel + Cover Glass (LCD & OLED)
• Polarizing foil (POL) attaching, touch screen panel (TSP) attaching, etc.
• Foldable: panel + CU sheet attaching, polyimide (PI) + panel attaching, etc.

Specification:

• Film supply method: Magazine type
• Cleaning: USC, Plasma, Roller
• Panel Size: Min 1 inch, Max 18 inch (TBD)
• Alignment Type: Vision align

This equipment combines cover glass and OLED panel using SHINDO's original 3D silicone shape pad with vacuum and pressure.

Application:

• 3D cover glass + deco film lamination (manual type)
• 3D cover glass + OLED lamination (inline type)
• Attach 4‑side curved panels
• High curvature

Specification:

• Film supply method: Magazine type
• Cleaning: USC, Plasma, Roller
• Panel Size: Min 1 inch, Max 18 inch (TBD)
• Alignment Type: Vision align

This equipment laminates functional films such as touch screen panel (TSP), polarizing film (POL), cover film and OLED / LCD panels using optically clear adhesives (OCA) or optical clear resin (OCR). The roll lamination method is applied after cleaning processes such as ultrasonic cleaning (USC) and plasma.

Application:

• Attach standard 2D functional film + OLED/LCD panel
• Functional films: TSP / POL / OCA / cover film / PORON

Specification:

• Film supply method: Magazine type
• Cleaning: USC, Plasma
• Panel Size: Min 1 inch, Max 18 inch (TBD)
• Alignment Type: Vision align

Vacuum assembly machines are well suited to combine cell assembly with integrated filling of the cell with liquid crystals. This technology is called one drop filling (ODF) because the exact volume of liquid crystal required to fill the cell is dispensed onto the lower glass plate before cell assembly. The method requires extremely precise dispensing: too much liquid causes overflow during assembly and pressing, too little leaves bubbles. Vacuum assembly is necessary to avoid entrapped gas bubbles.

The ODF machine from our partner Shindo Eng. Lab. can be combined with the vacuum assembly machines shown above.

The ODF system dispenses liquid crystal quantitatively using a small precision dispenser after the main seal and throughout the vacuum assembly.

Application:

• ECM room mirror / side mirror / sun roof / 3D display
• LCD display / TV display

Specification:

• Product Size: 65 inch (TBD)
• Dispenser: Contactless jetting type
• Sealant Type: Dispenser / screen
• Lamination Type: Vacuum lamination
• Alignment: U, V, W 3‑shaft

Since ODF technology is very precise and therefore used for high‑quality displays, the assembly procedure is usually followed by another process step: smallest bubbles are removed in an autoclave. Microbubbles are not visible immediately after ODF but can form visible bubbles later. Using an autoclave prevents formation of visible bubbles and further improves quality.

Crystec Technology Trading GmbH can offer equipment from various manufacturers, adapted to your needs and specifications.