Uncovering the Secrets of LED Display Screens
Uncovering the Secrets of LED Display Screens
Do you know what is the core of the LED display quality? The answer is packaging technology!
Encapsulation technology is the key to the quality of LED display. However, in addition to professional, reliable and advanced encapsulation technology, encapsulation chip materials, encapsulation materials and process control are inextricably linked, with the rapid development of science and technology in contemporary society, the media industry, advertising, exhibition industry, wedding industry and other industries for the quality of the display screen is also with the increase in the quality of the LED components are increasingly high quality demand.
LED encapsulation mainly includes chips, solid crystal glue, bracket, encapsulation glue, bonding wire and other materials.
1. Chip
As the core of the LED device, it determines the luminous performance of the entire LED display, service life and other core issues. However, with the reduction of LED chip cost, LED chip size is cut smaller and smaller, so that a series of performance problems also come.
2. Glue
There are two main types of encapsulation glue: silicone, epoxy resin.
(1), silicone: silicone is relatively high relative price, has excellent insulation, dielectric properties and adhesion. Its disadvantage is that it is easy to absorb moisture, airtightness is weak. Therefore, in the LED device packaging applications used less.
(2), epoxy resin: epoxy resin is easy to aging, poor heat resistance, susceptible to moisture, and short-wave light, high temperature easily discolored and other properties. Epoxy resin has a certain degree of toxicity, LED thermal stress match is not high, largely affecting LED performance and life.
3.LED bracket
(1) the structure of the stent to improve the design, PLCC stent by PPA and metal for physical combination, in the high temperature reflow furnace after the gap will become larger, so that water vapor is easy to enter the device along the metal channel inside the device, resulting in affecting the reliability of the product.
(2) the production process of the stent, PLCC stent production process mainly includes metal strip punching, plating, PPA (polyphthalamide) injection molding, bending, five-sided three-dimensional inkjet and other processes. Among them, plating, metal substrate, plastic materials, etc. occupy the main cost of the stent.
(3) The role of the bracket. PLCC (Plastic Leaded Chip Carrier) bracket is the carrier of the SMD LED device, the reliability of the LED, light and other properties play a key role.
4. Bonding wire
LED device packaging commonly used bonding wire including gold wire, copper wire, palladium-plated copper wire and alloy wire.
(1) palladium-plated copper wire: palladium-plated copper wire is also known as “palladium-plated bonding copper wire”. Palladium-plated copper wire has the advantages of good welding into the ball, high degree of oxidation resistance, high mechanical strength, moderate hardness, etc., so it is widely used in high-density multi-pin integrated circuit packages.
(2) gold wire: gold wire is widely used, the most mature technology. However, it is expensive, which leads to higher packaging costs of LED.
(3) Copper wire: cheap, better heat dissipation, welding line process of intermetallic compounds grow slowly is its outstanding advantages. But easy to oxidize, high hardness and high strain strength, especially in the bonding copper burning ball process, copper is very easy to oxidize, the formation of the oxide film reduces the bonding performance, which puts forward higher requirements for the actual production process of process control.
The better the materials used in each step of the encapsulation, the more exquisite and meticulous encapsulation technology, then the more excellent the quality of the display.
Encapsulation technology is the key to the quality of LED display. However, in addition to professional, reliable and advanced encapsulation technology, encapsulation chip materials, encapsulation materials and process control are inextricably linked, with the rapid development of science and technology in contemporary society, the media industry, advertising, exhibition industry, wedding industry and other industries for the quality of the display screen is also with the increase in the quality of the LED components are increasingly high quality demand.
LED encapsulation mainly includes chips, solid crystal glue, bracket, encapsulation glue, bonding wire and other materials.
1. Chip
As the core of the LED device, it determines the luminous performance of the entire LED display, service life and other core issues. However, with the reduction of LED chip cost, LED chip size is cut smaller and smaller, so that a series of performance problems also come.
2. Glue
There are two main types of encapsulation glue: silicone, epoxy resin.
(1), silicone: silicone is relatively high relative price, has excellent insulation, dielectric properties and adhesion. Its disadvantage is that it is easy to absorb moisture, airtightness is weak. Therefore, in the LED device packaging applications used less.
(2), epoxy resin: epoxy resin is easy to aging, poor heat resistance, susceptible to moisture, and short-wave light, high temperature easily discolored and other properties. Epoxy resin has a certain degree of toxicity, LED thermal stress match is not high, largely affecting LED performance and life.
3.LED bracket
(1) the structure of the stent to improve the design, PLCC stent by PPA and metal for physical combination, in the high temperature reflow furnace after the gap will become larger, so that water vapor is easy to enter the device along the metal channel inside the device, resulting in affecting the reliability of the product.
(2) the production process of the stent, PLCC stent production process mainly includes metal strip punching, plating, PPA (polyphthalamide) injection molding, bending, five-sided three-dimensional inkjet and other processes. Among them, plating, metal substrate, plastic materials, etc. occupy the main cost of the stent.
(3) The role of the bracket. PLCC (Plastic Leaded Chip Carrier) bracket is the carrier of the SMD LED device, the reliability of the LED, light and other properties play a key role.
4. Bonding wire
LED device packaging commonly used bonding wire including gold wire, copper wire, palladium-plated copper wire and alloy wire.
(1) palladium-plated copper wire: palladium-plated copper wire is also known as “palladium-plated bonding copper wire”. Palladium-plated copper wire has the advantages of good welding into the ball, high degree of oxidation resistance, high mechanical strength, moderate hardness, etc., so it is widely used in high-density multi-pin integrated circuit packages.
(2) gold wire: gold wire is widely used, the most mature technology. However, it is expensive, which leads to higher packaging costs of LED.
(3) Copper wire: cheap, better heat dissipation, welding line process of intermetallic compounds grow slowly is its outstanding advantages. But easy to oxidize, high hardness and high strain strength, especially in the bonding copper burning ball process, copper is very easy to oxidize, the formation of the oxide film reduces the bonding performance, which puts forward higher requirements for the actual production process of process control.
The better the materials used in each step of the encapsulation, the more exquisite and meticulous encapsulation technology, then the more excellent the quality of the display.