How to control light parameters during LED lamp production

 At present, domestic LED lamp manufacturers generally only care about light parameters in the design stage. What kind of chip to choose, what kind of driver to match, how to dissipate heat, etc. However, there is no effective control method in the production process, including large companies. How to control light parameters in an all-round way during the production process?

　　First of all, we need to check whether the parameters of each roll of chips are consistent with the labels of each roll during the incoming material inspection. Generally speaking, the chips of big brands are unlikely to be wrong in the whole roll, so it is enough to test one or two chips. The parameters mainly include luminous flux, color temperature, power, current, voltage, etc. For small brands, we need to increase the sampling ratio.

　　During the production process, material delivery inspection and record keeping are essential. The material loading records must be complete down to the color temperature and even different partitions. This process is often overlooked because everyone thinks it is a simple action. In order to prevent mistakes, in addition to detailed records, someone must check before putting it on the SMT line. Of course, it is also possible that the color temperature is wrong due to negligence. It is best to use barcode control, special racks for special purposes, and different barcodes cannot be installed, which avoids the possibility of manual errors.

　　Next, the quality of the patch also affects the normal use of the chip, such as cold soldering, high solder paste temperature and chip burnout, static electricity breakdown of the chip, etc. Therefore, the expiration date of the solder paste should be checked regularly, and it is strictly forbidden to use expired solder paste. Regular cleaning and checking of the tension of the steel mesh can ensure the thickness and integrity of the solder paste. Testing the thrust and thickness of the solder paste after printing the solder paste on the PCB board can ensure the subsequent welding quality. Few lamp factories really do this. It is best to use a temperature sensor on the PCB board to control the furnace temperature curve, so that there will be no accidents of burning the chip due to excessive temperature. For static protection, check the static ring at the door, and all workers must wear static rings and static clothing. The entire floor has an anti-static protective layer, and all workbenches and transfer devices must be made of anti-static materials. Corrugated boxes are not anti-static, which is little known. Many workers use corrugated cardboard to separate PCB boards for convenience, which is very dangerous. The entire workshop must be an isolated purification workshop with temperature and humidity control.

　　After the LED chip is mounted, it needs to be lit up for testing. Generally, the factory is in a hurry and only uses a small current to light up to screen whether the LED is properly mounted. Everyone expects the aging test behind the lamp to find out the problem. In fact, this is a common problem in LED lamp factories. It is best to test the relevant light parameters after the LED board is mounted to avoid rework in the later stage of production. At present, the domestic online detection is still relatively weak, and few companies can do online inspection, because there are not many LED lamps in production now, but it is possible for LED light sources because of the large quantity. There are also many people who think it is unnecessary, as long as the LED chip is selected well, all parameters can be guaranteed, which is obviously different from reality. If it cannot be done online, at least a few of each batch should be sent to the integrating sphere for testing.

　　When it comes to lamp assembly, the incoming material inspection should be the same as the LED board inspection, with samples sent to an integrating sphere to measure all parameters. During the assembly process, inspections should also be conducted every two hours. The final inspection before storage is also essential.

　　Some tests can be done during aging. Currently, everyone checks the brightness and color temperature with their own eyes, but this is greatly affected by human factors. Finally, it is possible to measure parameters while aging, which requires a set of equipment to ensure. I believe that as LED products become more and more mature, this kind of equipment will definitely be available in the near future!