LED lamp beads are mainly composed of five materials: bracket, silver glue, chip, gold wire, and epoxy resin.
LED lamp bead bracket
1. The role of the bracket: conduction and support
2. The composition of the stent: The stent is formed by electroplating the stent material, and consists of five layers of material, copper, nickel, copper, and silver from the inside to the outside.
3. Types of brackets: the cup bracket is the condensing type, and the flat-head bracket is the large-angle astigmatism type.
LED lamp beads silver glue
1. The role of silver glue: fix the chip and conduct electricity.
2. The main components of silver glue: silver powder accounts for 75-80%, EPOXY (epoxy resin) accounts for 10-15%, and additives account for 5-10%. Public number: Shenzhen LED Network
3. The use of silver glue: refrigerate, thaw and stir well before use, because the silver powder will precipitate after the silver glue is left for a long time. If it is not stirred evenly, it will affect the performance of the silver glue.
LED lamp chip
1. The role of the wafer: The wafer is the main component of the LED Lamp, and it is a light-emitting semiconductor material.
2. The composition of the wafer: the wafer is made of gallium phosphide (GaP), gallium aluminum arsenide (GaAlAs), gallium arsenide (GaAs), gallium nitride (GaN) and other materials, and its internal structure has unidirectional conductivity.
3. The structure of the chip: single-wire positive polarity (P/N structure) chip, double-wire chip. The size unit of the chip: mil, the bonding pad of the chip is generally a gold pad or an aluminum pad. The pad shapes are round, square, cross and so on.
4. The light-emitting color of the wafer: The light-emitting color of the wafer depends on the wavelength, and the classification of common visible light is roughly: dark red (700nm), deep red (640-660nm), red (615-635nm), amber (600-610nm) , Yellow (580-595nm), yellow-green (565-575nm), pure green (500-540nm), blue (450-480nm), purple (380-430nm).
White light and pink light are a kind of mixed effect of light. The most common is a mixture of blue + yellow phosphor and blue + red phosphor.
5. The main technical parameters of the chip:
A. The volt-ampere characteristic diagram of the chip;
B. Forward voltage (VF): The voltage applied to both ends of the wafer to make the wafer forward conduction. This voltage has a corresponding relationship with the wafer itself and the test current. If VF is too large, the chip will be broken down.
C. Forward current (IF): The forward conduction current generated by the chip after a certain voltage is applied. The magnitude of IF is related to the magnitude of the forward voltage. The working current of the chip is about 10-20mA.
D. Reverse voltage (VR): The reverse voltage applied to the chip. Public number: Shenzhen LED Network
E. Reverse current (IR): refers to a leakage current generated by the chip after applying a reverse voltage. The smaller the current, the better. Because the current is large, it is easy to cause the chip to be reversed breakdown.
F. Brightness (IV): refers to the brightness of the light source. Unit conversion: 1cd=1000mcd
G. Wavelength: reflects the luminous color of the chip. Wafers of different wavelengths have different light-emitting colors. Unit: nm
LED lamp beads gold wire
1. The role of the gold wire: connect the chip PAD (pad) and the bracket, and make it conductive.
The purity of the gold wire is 99.99% Au; the elongation rate is 2-6%. The size of the gold wire is: 0.9mil, 1.0mil, 1.1mil and so on.
LED lamp beads epoxy resin
1. The role of epoxy resin: protect the internal structure of the Lamp, can slightly change the color, brightness and angle of the lamp; make the Lamp shape.
2. The encapsulation resin consists of four parts: A glue (main agent), B glue (hardener), DP (diffusing agent), and CP (coloring agent). Its main components are epoxy resin (Epoxy Resin), acid anhydride (anhydride acid), high light diffusion filler (Light diffusion) and thermal stability dye (dye).
