SMD LED display processing method
1. Printing: Modern solder paste printers generally consist of plate loading, solder paste addition, imprinting, and circuit board transfer. When the solder paste printer is working, the circuit board to be printed is first fixed on the printing positioning table, and then the solder paste or red glue is printed on the corresponding pad through the stencil by the left and right scrapers of the printer. Input to the placement machine through the transfer station for automatic placement. 2. Patch: The led placement machine is a device that accurately places surface mount components on the pad by moving the placement head. It uses the guide rail or linear motor principle to control the drive head. At the same time, it must be equipped with a professional spunbond nozzle head. During the placement process, production defects such as sticking and rejection are eliminated as much as possible. At the same time, the tank chain of the LED placement machine requires more toughness and ductility to ensure its stability and service life. 3. Welding: Reflow soldering, in surface mount technology (SMT), refers to ingot-shaped or rod-shaped solder alloys, which are melted and remanufactured into tin powder (that is, spherical tiny tin balls), and then combined with organic auxiliary materials (flux) It is blended into solder paste; it is the process of printing, stepping on, patching, and remelting and solidifying into metal solder joints. The welding process is a special process. The operators engaged in the special process shall be trained to be qualified. The operators shall operate in strict accordance with the operation documents, and conduct self-inspection and mutual inspection. Four, overhaul: That means testing can be added to each process to achieve the purpose of quality control. Therefore, in the LED chip processing, so
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LED lighting production process
LED lighting production process material The five raw materials of LED are: chip, bracket, silver glue, gold wire, epoxy resin 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. 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) 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 &quo
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What are traffic lights?
What are traffic lights? Navigation lights have used LEDs as light sources for many years. The current work is to improve and perfect. Road traffic lights have made great progress in recent years, with rapid technological development and rapid application development. There are currently about 40,000 sets of orders in China each year. In California, the United States replaced 50,000 sets of traditional light source signal lights with LED traffic lights in the last year. According to the use effect, the long life, power saving and maintenance-free effects are obvious. At present, the peak wavelength of the LED light emission is red 630nm , Yellow 590nm, green 505nm. The problem that should be paid attention to is that the driving current should not be too large, otherwise the high temperature conditions under the summer sun will affect the life of the LED. Recently, LED airport-specific signal lights used in airports as beacon lights, floodlights and omnidirectional lights have also been successfully and put into use, and the results have been very good. It has independent intellectual property rights, has obtained two patents, and has good reliability. It saves electricity and is maintenance-free. It can be popularized and applied to various airports to replace the old signal lights that have been used for decades. Not only is the brightness high, but because the LED light color purity is good, it is particularly bright and easy to recognize. Railway signal lights require different light intensity and viewing angles due to their large variety series. They are currently being developed rapidly. It is estimated that they will gradually be successfully developed and put into application. In terms of quantity, it is also a fairly large market.
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What are the forms of LED luminescent materials used in display screens?
What are the forms of LED luminescent materials used in display screens? ① LED light-emitting lamp (or single lamp) It is generally composed of a single LED chip, reflector, metal anode, and metal cathode, and is covered with an epoxy resin shell with light-transmitting and light-concentrating ability. One or more (different colors) single lamps can be used to form a basic pixel. Due to the high brightness, it is mostly used for outdoor display screens. ② LED dot matrix module The light-emitting matrix is composed of a number of chips, which is encapsulated in a plastic case with epoxy resin. It is suitable for row and column scanning drive, easy to form a high-density display, and is mostly used for indoor display. ③ SMD LED light-emitting lamp (or SMD LED) is the package of the LED light-emitting lamp in the form of soldering, which can be used for indoor full-color display screens, which can realize single-point maintenance and effectively overcome the mosaic phenomenon.
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What is an LED display?
What is an LED display? LED display (LED display) is a flat panel display, composed of small LED module panels, used to display text, images, video, video signals and other information equipment. LED, light emitting diode (abbreviation of light emitting diode). It is a kind of diode made of compound of gallium (Ga), arsenic (As), phosphorus (P), nitrogen (N), and indium (In) by controlling the display mode of semiconductor light-emitting diodes. It can radiate visible light when recombined, so it can be used to make light-emitting diodes. Used as indicator lights in circuits and instruments, or composed of text or digital displays. Phosphor gallium arsenide diodes emit red light, gallium phosphide diodes emit green light, silicon carbide diodes emit yellow light, and indium gallium nitride diodes emit blue light.
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