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During a Universal Science delegation's recent visit to the Hangzhou factory, we were guided through the production process and quality control of the LED power supplies uPowerTek.

Table of Contents

upowertek LED power supplies

SMT

SMT production lines are fully automatic, equipped with a high-precision screen printer, high-speed Pick&place , a 10-zone remelt oven and various automatic optical equipment.

Before the product goes on line, the materials are placed in sequence according to code and then loaded into the feeder according to BOM. The solder alloyis stored in a dedicated cooler at 2-10°C and is then heated and mixed naturally before use.The PCB loading also automatic by spatula evenly and precisely distributes the solder alloy with an accuracy of 0.005 millimeters,

The PCBso preparedissent to SPI (Solder Paste Inspection)and the 3Dintelligent vision system with 10µm resolution can quickly and accurately detect nonconforming deposition. After inspection, the PCB enters the next step the Pick&place After identification, components are placed on thePCBs in sequence according toproduct schedules Each production line is equipped with two sets of Yamaha YS series, high-speed, high-precision (0.02mm)placement machines thetwo machines together are capable of achieving a placement speed of 150,000 components/hour. The assembled PCB slides into the reflow solder to be optimally soldered. The oven icnlude a nitrogen chamber aninert gas is introduced into the soldering machine a to improve the reflow of solder paste distributed on the pad and finally solidify after cooling the air. The reflow oven is equipped with 10 temperature zones and the precision of temperature control reaches ±1°C, which ensures a smooth and defect-free soldering process, thus guaranteeing the quality of soldered joints. Once soldering is completed, the PCB enters AOI (Automatic Optical Inspection) based on the optical principle and the PCB is fully inspected p When the SMT process is complete, the PCBs are placed neatly on anti-static trolleys and ready for the next process.

Preprocessing

The pre-processing area covers through-hole (traditional) components and has a flexible setup: the automatic leg-cutter with vibrating plate replaces manual cutting, the high-precision cutting die-cutter reaches 0.2mm so as to ensure consistency, and the automatic screwing machines help workers fasten heatsinks. A fast professional programmer is also employed to burn firmware into the feeder microprocessor.

Plug-in

Advanced electronic SOP provides remote operating instructions to realize paper-free workflow, and alarm and lighting systems improve the efficiency of insertion operations. The ion generator can reduce static electricity to less than 200V by releasing positive and negative ions. All workers wear electrostatic discharge wristbands that are securely connected to the wristband alarms connected in real time to the entire anti-static system to prevent damage and improve product reliability.

Wave Welding

After the conventional component insertion process, the circuit board switches to the JT SE-350-H wave soldering machine, which has three preheating zones and uses inverter control of the hot air cycle. The dual wave peak adopts PID control technology, and the temperature accuracy is within ±1°C°. The wave soldering devices are made of synthetic material with temperature resistance above 300°C, which can ensure the quality of soldering of components on PCB at high ambient temperatures. The PCB moves on a conveyor belt and slowly introduced into the machine with a 500 kg solder crucible and excellent heat capacity. The solder material is SnAgCu complying with RoHs lead-free standards where silver ensures good ductility and reliability of solder joints. The solder temperature curve is monitored regularly and the zone temperature stays within 265±10°C. The weld quality strictly follows IPC-610 and related standards. The soldering phase takes 3-6 seconds, and the depth control is 3-5 mm to ensure that each solder joint can form a good IMC (intermetallic compound), so that the component and the circuit will combine firmly.

Auto Test 1

Post Soldering long pins are cut to avoid puncturing the mylar sheet Visual inspection of the wave solder joints then follows. Each driver is wrapped with mylar sheet to ensure the insulations, then the circuit board with mylar sheet is inserted into the LED driver shell and the input and output end caps are assembled. Then the product is retested by ATS (Auto Testing System) where high-power electronic loads from the IT88 series independently developed by Upowertek with an accuracy of 0.01 mV/1 mA are used. This system is also compatible with the 20-2500W power level. The ATS verifies key electrical parameters, including input voltage, output voltage, output current, power factor, efficiency, and control parameters. For each barcode scan, the test results are saved in the cloud, which is useful for traceability.

Potting

Four-axis automatic filling machines with a stroke of 800x1000mm and trace accuracy of 0.5mm are used, which have protection functions such as that from flow interruption, over-temperature and abnormal resin mixing. The automatic heating function, on the other hand, ensures resin insertion quality. Density is tested daily before filling as 6 samples are taken every two hours to ensure that the hardness of curing at each point reaches the standard of 55±10 shore. All samples are stored for traceability. The stability of the potting machine controls the mixing ratio and the speed of resinating to make sure each feeder is 100% filled. The 2 kW high-power vacuum machine can reduce air pressure to -0.09mpa in 1 minute to achieve rapid vacuum foam removal. The double vacuum process ensures that there are no bubbles inside the LED driver, a critical step for the reliability of high-power LED drivers.

Aging Test

The products are moved to the aging cell for four hours of run-in, which is an important guarantee of reliability. The 8 sets of CPET energy recovery aging machines with 600W electronic load for each channel are used to perform 100% testing equipped with 8 aging machines with 192 channels each. 1536 parts are tested simultaneously, which greatly improves the aging speed. The aging system monitors in real time and records input and output parameter data. Once a defective product is found, the system automatically alarms by reporting it to the monitoring center for lidentification and asclusion. I energy recovery system ensures a 60 percent return to the grid by reducing costs and improving compatibility parameters to the standards of a green company.

High power testing

Once the Aging Test is completed, a high-power electrical resistance or insulation test is performed on each product. According to different safety standards, different voltages are applied between the input and output from the 4-channel high-voltage test equipment, the ATS warning once the leakage current exceeds the limit.

Auto Test 2

LED drivers that pass the high-power test will again undergo final testing by ATS, where the test setup is basically the same as the initial test covering many parameters such as input, output efficiency, power factor, and dimming. After the barcode is scanned, the data from this test is also uploaded to the cloud.

Packaging

After all inspections have been completed, it is time for the final packaging process. Any remaining residue on the product surfaces is removed, the label size is checked in advance by an infrared device, and appearance inspection is performed again after the label is applied. With customized cartons, products are packed according to different specifications. The process ends with the automatic carton sealing machine with a speed of up to ten boxes per minute.

LED Power Supplies Catalog 2024

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