Complete GOB Process Steps for LED Display Modules

Modules with SMD lamp beads mounted and soldered are powered on for 72-hour aging to screen defective units with dead pixels, color difference and cold solder joints. Clean dust and oil stains on qualified boards.

2.Plasma surface activation cleaning

Use plasma equipment to bombard PCB and lamp bead surfaces to eliminate static electricity and oxide layers, greatly improve adhesion between glue, substrate and beads, and prevent glue peeling in later use.

3.Mixing of special GOB optical AB glue

Mix high-transparency anti-yellow epoxy AB glue in fixed proportion and stir evenly to avoid glue delamination which harms light transmission and curing performance.

4.Vacuum defoaming of glue

Put mixed glue into vacuum defoamer for 5–10 minutes under negative pressure to fully remove tiny air bubbles generated during stirring, preventing white spots, voids and light spots after curing.

5.Module positioning & precision vacuum glue filling

Fix modules in customized molds and send them into vacuum glue filling chamber. Inject glue evenly under negative pressure to fully fill gaps between lamp beads and cover bead surfaces, precisely control glue thickness at 300–500μm.

6.Static leveling at normal temperature

Leave modules in constant-temperature dust-free workshop for 10–30 minutes for automatic glue leveling, eliminate glue lines and ensure uniform glue thickness and smooth surface without ripples.

7.Stepwise high-temperature curing

Bake and cure by staged heating: standard procedure is 2 hours at 80℃ + 2 hours at 120℃. Slowly release internal stress of glue layer to avoid cracking and edge warping.

8.CNC precision edge trimming on four sides

Cut four sides of cured modules by CNC cutting machine to remove excess glue, unify dimensional tolerance for seamless splicing.

9.Appearance & optical AOI inspection

Scan full boards via automatic optical inspector to detect defects including bubbles, pinholes, insufficient glue, uneven glue thickness and surface scratches; rework defective products with supplementary gluing.

10.Secondary power-on aging & full function test