LED lighting production process

LED lighting production process
The five raw materials of LED are: chip, bracket, silver glue, gold wire, epoxy resin
The composition of the chip: It is composed of gold pad, P pole, N pole, PN junction, and back gold layer (double pad chip without back gold layer). The wafer is a PN combination composed of P-layer semiconductor elements and N-layer semiconductor elements rearranged and combined by the movement of electrons. It is this change that enables the wafer to be in a relatively stable state. When the wafer is applied with a certain voltage to the forward electrode, the holes in the forward P area will continuously swim to the N area, and the electrons in the N area will move to the P area relative to the holes. While the electrons and holes move relative to each other, the electrons and holes pair with each other to excite photons and generate light energy. Main classification, surface emitting type: Most of the light is emitted from the surface of the wafer. Five-sided luminous type: There are more light emitted from the surface and sides according to the luminous color, red, orange, yellow, yellow-green, pure green, standard green, blue-green, and blue.
The structure of the bracket is 1 layer of iron, 2 layers of copper plating (good conductivity, fast heat dissipation), 3 layers of nickel plating (anti-oxidation), 4 layers of silver plating (good reflectivity, easy to wire)
Silver glue (due to more types, we take H20E as an example)
Also called white glue, milky white, conductive adhesion (baking temperature: 100°C/1.5H) silver powder (conductive, heat dissipation, fixed chip) + epoxy resin (cured silver powder) + thinner (easy to stir). Storage conditions: Silver glue manufacturers generally store silver glue at -40 °C, and application units generally store silver glue at -5 °C. Single agent is 25 °C/1 year (in a dry and ventilated place), mixed agent is 25 °C/72 hours (but due to other factors "temperature, humidity, and ventilation conditions" during online operation, to ensure the quality of the product is average (The use time of the mixture is 4 hours)
Baking conditions: 150 °C/1.5H
Stirring conditions: Stir evenly in one direction for 15 minutes
Gold wire (take φ1.0mil as an example)
The gold wires used in LEDs are φ1.0mil, φ1.2mil, and the material of the gold wire. The material of the gold wire for LED generally contains 99.9% gold. The purpose of the gold wire
Utilizing its high gold content, soft material, easy deformation, good electrical conductivity, and good heat dissipation characteristics, a closed circuit is formed between the chip and the support.
Epoxy resin (take EP400 as an example)
Composition: A and B two components:
Glue A: It is the main agent, composed of epoxy resin + defoamer + heat-resistant agent + thinner
Agent B: It is a curing agent, composed of acid + release agent + accelerator
Conditions of Use:
Mixing ratio: A/B=100/100 (weight ratio)
Mixing viscosity: 500-700CPS/30 °C
Gel time: 120 °C*12 minutes or 110 °C*18 minutes
Usable conditions: room temperature 25 °C about 6 hours. Generally, according to the production needs of the production line, we set its use condition as 2 hours.
Curing conditions: initial curing 110 °C-140 °C 25-40 minutes
Post-curing 100 °C*6-10 hours (flexible adjustments can be made according to actual needs)