Small pitch LED full color display screen related process
Small pitch LED full color display screen related process
With the reduction of cost, as well as the progress of the process, small pitch LED full color display screen has gradually become the favorite of the market, what is special about the process of small pitch? Why is it so favored by the market?
1 encapsulation:
Conventional LED full-color display screen generally use 3528, 2727 lamps, LED pin shape using J or L encapsulation. Lateral welding pins, welding area will have reflections, poor ink color effect, inevitably need to increase the mask to improve contrast. With the bead density further increase, L or J package has been difficult to meet production requirements, many manufacturers have begun to use QFN package. It is characterized by no lateral welding pins, welding area without reflection, thus making the color effect is very good. In addition, the use of all-black integrated design molding, screen contrast increased by more than 50%, making a better display.
2 printed circuit board:
With the development of small pitch LED full color display, 2 layer PCB version has been difficult to meet, at present 4 layer, 6 layer board is gradually adopted, the new printed circuit board using microfine over-hole and buried holes in the design of the printed circuit graphic wire fine, microporous narrow pitch, the use of laser drilling technology can meet the microfine hole processing.
3 Printing:
Too much, too little amount of solder paste and the offset of printing directly affects the welding quality of the micro-pitch display lamp. The correct PCB pad design needs to be implemented into the design after communicating with the manufacturer, the opening size of the stencil and the printing parameters are correct or not directly related to the amount of solder paste printed. General 2020RGB devices using 0.1-0.12mm thickness of electropolished laser stencil, 1010RGB devices below the recommended thickness of 1.0-0.8 stencil. Thickness, opening size and tin volume proportionally increasing. Micro-pitch LED welding quality and solder paste printing is closely related, with thickness detection, SPC analysis and other functions of the use of the printing machine will play an important role in reliability.
4 placement:
Micro-pitch display each RGB device position of the slightest offset will lead to the LED full-color display screen body display is not uniform, will inevitably require placement equipment with higher precision.
5 welding:
Reflow soldering temperature rise too fast will lead to wetting imbalance, is bound to cause the device in the wetting imbalance process leads to offset. Excessive wind cycle will also cause displacement of the device. Try to choose more than 12 temperature zone reflow soldering machine, chain speed, temperature rise, cycling wind, etc. as a strict control of the project, that is, to meet the needs of welding reliability, but also to reduce or prevent the displacement of the device, as far as possible to control to the needs of the range. Generally 2% range of pixel pitch as a control value.
6 cabinets assembly:
Cabinets are spliced with different modules, the flatness of the Cabinet and the gap between the modules is directly related to the overall effect of the Cabinets assembly. Aluminum processing Cabinets, cast aluminum Cabinets is now widely used Cabinets type, flatness can reach within 10 silk. The splicing gap between modules is evaluated by the spacing of the nearest pixels of two modules, two pixels are too close to light up a bright line, two pixels are too far away will result in a dark line. Before assembly, it is necessary to measure and calculate the module splicing gap, and then choose the relative thickness of the metal sheet as a fixture inserted beforehand for assembly.
7 screen body assembly:
Assembly of the completed Cabinets needs to be assembled into a screen before you can display the refined picture, video. However, the Cabinets itself size tolerance and assembly cumulative tolerance of micro-pitch display assembly effect should not be ignored. Cabinets and Cabinets between the nearest device pixel spacing is too large, too small will lead to display dark lines, bright lines. Dark line, bright line problem is now micro-pitch display can not be ignored need to urgently overcome the problem. Localized companies through
Stick 3m tape, Cabinets fine adjustment nut to adjust to achieve the best results.
8 control system:
Small pitch LED full color display due to its special display effect, the general control system is difficult to achieve the display effect, so many manufacturers have developed a related high-definition LED control system, high-performance control system will be better to show the advantages of small pitch display.
Summary: small pitch LED full color display is a new design of the display system, optimization and new technology makes the small pitch to play its inherent display advantages, the current completely and can be comparable to the DIP LCD splicing screen display effect, it can be said with certainty that the era of small pitch LED has arrived.
1 encapsulation:
Conventional LED full-color display screen generally use 3528, 2727 lamps, LED pin shape using J or L encapsulation. Lateral welding pins, welding area will have reflections, poor ink color effect, inevitably need to increase the mask to improve contrast. With the bead density further increase, L or J package has been difficult to meet production requirements, many manufacturers have begun to use QFN package. It is characterized by no lateral welding pins, welding area without reflection, thus making the color effect is very good. In addition, the use of all-black integrated design molding, screen contrast increased by more than 50%, making a better display.
2 printed circuit board:
With the development of small pitch LED full color display, 2 layer PCB version has been difficult to meet, at present 4 layer, 6 layer board is gradually adopted, the new printed circuit board using microfine over-hole and buried holes in the design of the printed circuit graphic wire fine, microporous narrow pitch, the use of laser drilling technology can meet the microfine hole processing.
3 Printing:
Too much, too little amount of solder paste and the offset of printing directly affects the welding quality of the micro-pitch display lamp. The correct PCB pad design needs to be implemented into the design after communicating with the manufacturer, the opening size of the stencil and the printing parameters are correct or not directly related to the amount of solder paste printed. General 2020RGB devices using 0.1-0.12mm thickness of electropolished laser stencil, 1010RGB devices below the recommended thickness of 1.0-0.8 stencil. Thickness, opening size and tin volume proportionally increasing. Micro-pitch LED welding quality and solder paste printing is closely related, with thickness detection, SPC analysis and other functions of the use of the printing machine will play an important role in reliability.
4 placement:
Micro-pitch display each RGB device position of the slightest offset will lead to the LED full-color display screen body display is not uniform, will inevitably require placement equipment with higher precision.
5 welding:
Reflow soldering temperature rise too fast will lead to wetting imbalance, is bound to cause the device in the wetting imbalance process leads to offset. Excessive wind cycle will also cause displacement of the device. Try to choose more than 12 temperature zone reflow soldering machine, chain speed, temperature rise, cycling wind, etc. as a strict control of the project, that is, to meet the needs of welding reliability, but also to reduce or prevent the displacement of the device, as far as possible to control to the needs of the range. Generally 2% range of pixel pitch as a control value.
6 cabinets assembly:
Cabinets are spliced with different modules, the flatness of the Cabinet and the gap between the modules is directly related to the overall effect of the Cabinets assembly. Aluminum processing Cabinets, cast aluminum Cabinets is now widely used Cabinets type, flatness can reach within 10 silk. The splicing gap between modules is evaluated by the spacing of the nearest pixels of two modules, two pixels are too close to light up a bright line, two pixels are too far away will result in a dark line. Before assembly, it is necessary to measure and calculate the module splicing gap, and then choose the relative thickness of the metal sheet as a fixture inserted beforehand for assembly.
7 screen body assembly:
Assembly of the completed Cabinets needs to be assembled into a screen before you can display the refined picture, video. However, the Cabinets itself size tolerance and assembly cumulative tolerance of micro-pitch display assembly effect should not be ignored. Cabinets and Cabinets between the nearest device pixel spacing is too large, too small will lead to display dark lines, bright lines. Dark line, bright line problem is now micro-pitch display can not be ignored need to urgently overcome the problem. Localized companies through
Stick 3m tape, Cabinets fine adjustment nut to adjust to achieve the best results.
8 control system:
Small pitch LED full color display due to its special display effect, the general control system is difficult to achieve the display effect, so many manufacturers have developed a related high-definition LED control system, high-performance control system will be better to show the advantages of small pitch display.
Summary: small pitch LED full color display is a new design of the display system, optimization and new technology makes the small pitch to play its inherent display advantages, the current completely and can be comparable to the DIP LCD splicing screen display effect, it can be said with certainty that the era of small pitch LED has arrived.