2024-01-12
COB packaging process interpretation
COB packaging process interpretation
The packaging technology of COB is classified as packaging free or packaging mode, but this packaging method is not to save the packaging link, but to save the packaging process, compared with the patch process, the packaging process of COB to save several steps, to a certain extent, saving time and technology, but also to a certain extent, saving costs. SMD production process needs to go through solidification, welding wire, dispensing, baking, stamping, splitting color separation, ribbon, patch and other links, and COB process on this basis to simplify, first paste the IC on the circuit board and then solidification, welding wire, testing, dispensing, baking, become a finished product.
In terms of the production process alone, several steps are eliminated, and industry insiders say that in this way, a large part of the cost can be saved. It is worth noting that the packaging of COB does not require over-reflow soldering, which has become one of the advantages of COB.
Yang Rui, marketing director of Oreda, said that the conventional packaging is to place the lamp bead on the PCB board for welding, when the lamp is more and more dense, the lamp foot will be smaller and smaller, so the precision requirements for welding will be higher. How many lights are there in a square, a lamp has four feet, then a square will have many solder joints, at this time, the requirements for solder joints are very high, then the only solution is to reduce the solder joints. The stability of very small solder is very poor, it may be touched casually, it may fall off, which is an unavoidable problem of SMD; The key difference is to remove the solder process, SMD in the solder process, the control of temperature is extremely difficult to master, the temperature is too high, will cause damage to the lamp, too low, the solder is not completely melted. It is easy to cause virtual welding, false welding and other phenomena, which is a big challenge to improve the stability of the lamp bead. COB does not have this process, so the stability will be greatly improved.
The processing technology of the traditional LED display is relatively diverse, especially in the process of reflow welding, the expansion coefficient of the SMD lamp bead bracket and the epoxy resin is not the same at high temperature, which is easy to cause the bracket and the epoxy resin encapsulation shell to fall off, and there is a gap, and the dead lamp phenomenon gradually appears in the later use, resulting in a high defect rate. The COB display is more stable because there is no reflow paste lamp in the processing process, even if there is a later reflow paste IC process, the diode chip has been packaged with epoxy resin curing protection, avoiding the problem of gap between the lamp bead bracket and epoxy resin caused by high temperature soldering in the welding machine.
In terms of the production process alone, several steps are eliminated, and industry insiders say that in this way, a large part of the cost can be saved. It is worth noting that the packaging of COB does not require over-reflow soldering, which has become one of the advantages of COB.
Yang Rui, marketing director of Oreda, said that the conventional packaging is to place the lamp bead on the PCB board for welding, when the lamp is more and more dense, the lamp foot will be smaller and smaller, so the precision requirements for welding will be higher. How many lights are there in a square, a lamp has four feet, then a square will have many solder joints, at this time, the requirements for solder joints are very high, then the only solution is to reduce the solder joints. The stability of very small solder is very poor, it may be touched casually, it may fall off, which is an unavoidable problem of SMD; The key difference is to remove the solder process, SMD in the solder process, the control of temperature is extremely difficult to master, the temperature is too high, will cause damage to the lamp, too low, the solder is not completely melted. It is easy to cause virtual welding, false welding and other phenomena, which is a big challenge to improve the stability of the lamp bead. COB does not have this process, so the stability will be greatly improved.
The processing technology of the traditional LED display is relatively diverse, especially in the process of reflow welding, the expansion coefficient of the SMD lamp bead bracket and the epoxy resin is not the same at high temperature, which is easy to cause the bracket and the epoxy resin encapsulation shell to fall off, and there is a gap, and the dead lamp phenomenon gradually appears in the later use, resulting in a high defect rate. The COB display is more stable because there is no reflow paste lamp in the processing process, even if there is a later reflow paste IC process, the diode chip has been packaged with epoxy resin curing protection, avoiding the problem of gap between the lamp bead bracket and epoxy resin caused by high temperature soldering in the welding machine.
