5 major materials for LED lights: chip, bracket, silver glue, gold wire, epoxy resin.
1. Chip
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.
Second, the bracket
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)
3. Silver glue (because of 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).
4. 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.
5. 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 consisting of acid + release agent + accelerator.
Post time: Aug-11-2021 BACK