Raw materials: LED bracket; LED chip; LED solid crystal glue; welding wire; LED packaging glue; LED phosphor; mainly the above materials.
Equipment: automatic crystal fixing machine; plasma cleaning machine; automatic wire bonding machine; automatic glue dispenser; glue mixer; oven; slitting machine; automatic sorting machine; automatic packaging machine;
Production environment: LED packaging factories generally require a 100,000-level dust-proof requirement; in the dispensing room, higher protection may be required, hopefully a 10,000-level dust-proof; the back-end testing and sorting requirements are lower, and a million-level dustproof is enough. However, good electrostatic protection is required throughout the entire process, because the LED chip is afraid of electrostatic breakdown.
The first step: SMD LED lamp beads LED bracket inspection. Main test items: appearance size, thickness of electroplating layer, whether there is oxidation. Suggested tools: two-dimensional measuring instrument, film thickness measuring instrument, metallographic microscope.
The second step: SMD LED lamp beads LED bracket baking. The use of equipment to bake the LED bracket is mainly to remove the residual water vapor during the injection molding process of the bracket.
Step 3: Plasma cleaning of SMD LED lamp beads and LED bracket. Plasma cleaning is mainly to form an electric arc with hydrogen and oxygen inside the equipment to remove the residual organic matter on the surface of the LED bracket and improve the bonding force of the die.
The fourth step: SMD LED lamp beads solid crystal. The LED chip is bonded to the LED bracket with LED die-bonding glue through an automatic die-bonding machine.
Step 5: SMD LED lamp bead baking. Bake the die-bonding glue to make the LED chip and the LED bracket form a good bond. After the baking is finished, a solid crystal thrust test is required. The equipment used is very expensive, such as a push-pull force tester.
Step 6: SMD LED lamp bead welding wire. The soldering pad on the LED chip and the conductive area on the LED bracket are soldered with metal wires. There are several types of welding: gold wire spherical welding and wedge welding. The metal wires used are: gold wire, aluminum wire, alloy wire, copper wire, etc., LED lamp beads mainly use gold wire, alloy wire and copper wire. After the welding is completed, the size of the welding point and the welding tension should be measured. This is a very critical step. Most LED dead lights are caused by soldering problems.