1. Common welding methods can be divided into soldering iron welding, heating platform welding, and reflow soldering

A： Soldering with an electric soldering iron is the most common method, such as sample making and maintenance. Due to the fact that most existing manufacturers buy back unqualified and inferior electric soldering irons to save costs, most of them have poor grounding and leakage. During the soldering process, this is equivalent to forming a circuit between the leaking soldering iron tip, the LED being soldered, the human body, and the earth, which means that the voltage borne by the LED bead is applied tens to hundreds of times, instantly burning it out.

Note: The situation of connecting to an electrostatic belt will be more serious, because when the human body is connected to an electrostatic belt, the resistance to the ground forming a circuit will be smaller, and the current passing through the human body to the lamp beads will be larger. This is also the problem that many people have said is that even with an electrostatic belt, there are still so many lamp beads damaged.

B： The dead lights caused by welding on the heating platform, due to the continuous supply of lamp sample orders, have become the best production tool for most enterprises to meet the needs of small batches and sample orders. Due to the advantages of low equipment cost, simple structure and operation, the heating platform has become the best production tool. However, due to the use environment (such as temperature instability in places with fans) and the control of welding operators' proficiency and welding speed, the dead lights have become a major problem. In addition, the grounding situation of the heating platform equipment.

C： Reflow soldering is generally the most reliable production method and suitable for large-scale production and processing. Improper operation can cause more serious dead light consequences, such as improper temperature adjustment and poor machine grounding.

2. Improper storage causing dead lights:

This type of problem is most common: due to the lack of attention to moisture prevention after opening the package, and the use of silicone material for sealing the lamp beads; Silicone material has certain water absorption properties. After the lamp beads are attached to the board due to moisture, the silicone will undergo high-temperature welding process, causing thermal expansion and contraction. The gold wire, chip, and bracket will deform, causing the gold wire to shift and break, resulting in the phenomenon of the lamp not turning on.

Therefore, it is recommended to store LEDs in a dry and ventilated environment with a storage temperature of -40 ℃ -+100 ℃ and a relative humidity below 85%; It is best to use the LED within 3 months under its original packaging conditions to avoid rusting of the bracket; After opening the packaging bag of the LED, it should be used up as soon as possible. At this time, the storage temperature is 5 ℃ -30 ℃, and the relative humidity is below 60%.

3. Chemical cleaning:

Do not use unknown chemical liquids to clean the LED, as it may damage the surface of the LED gel and even cause gel cracks. If necessary, please clean it with an alcohol swab in a room temperature and ventilated environment, preferably within one minute.

4. Deformation causes dead lights:

Due to deformation of some lamp boards, operators will need to shape them. As the board undergoes deformation, the lamp beads on top also deform together, causing the gold wire to break and the lights to not light up. It is recommended that this type of board be shaped before production. It is common for deformation and breakage of gold wires to occur during production assembly and handling processes.

Another issue is stacking. In the production process, for the sake of convenience, the lamp boards are stacked randomly. Due to gravity, the lower layer of lamp beads will deform under stress, damaging the gold wire.

5. Mismatch between heat dissipation structure, power supply, and lamp board:

Due to unreasonable power supply design or selection, the power supply exceeds the maximum limit that the LED can withstand (overcurrent, instantaneous impact); Unreasonable heat dissipation structure of lighting fixtures can cause dead lights and premature light decay.

6. Factory grounding:

It is necessary to check whether the main grounding wire of the factory is in good condition.

7. Static electricity:

Static electricity can cause LED malfunction, it is recommended to prevent ESD damage to LEDs.

A：During LED testing and assembly, operators must wear anti-static wristbands and gloves.

B：Welding equipment, testing equipment, workbenches, storage racks, etc. must be well grounded.

C：Use an ion fan to eliminate static electricity generated by friction during storage and assembly of LEDs.

D：The material box for LED is made of anti-static material box, and the packaging bag is made of electrostatic bag.

E： Don't have a lucky mentality, just touch the LED casually.

The abnormal phenomena that may occur in LEDs damaged by ESD include:

A： Reverse leakage may cause a decrease in brightness in mild cases, and the light may not turn on in severe cases.

B： The forward voltage value decreases. The LED cannot emit light when driven with low current.

C： Poor welding results in the lights not turning on.

Welding conditions

Reflow soldering: Please preheat at 150 ℃ within 2 minutes, and then perform soldering once at 240 ℃ within 5 seconds after heating.

Soldering: Use a controllable temperature soldering iron with a maximum power of 25W, with a tip temperature not exceeding 320 ℃, and complete the soldering process once within 3 seconds.

Do not apply external force to the product during welding. Do not bend the circuit board after welding is completed.

packing:

Due to the moisture absorption of resin during welding, it may cause moisture evaporation and expansion, which may lead to interface delamination. Therefore, the purpose of moisture-proof packaging is to ensure that the moisture inside the packaging bag is minimized.

The product should be used within one year from the date of self packaging. Before the packaging bag is opened, it should be stored in an environment with a temperature of 5-30 ℃ and a relative humidity of<60%.

After the packaging bag is opened, the product must be welded and used within 24 hours. Otherwise, the product must be stored in an environment with a temperature of 5-30 ℃ and a relative humidity of<30% for no more than one week; If there are any unused products, please put them back

Sealed storage in moisture-proof bag:

If the product exceeds the above storage requirements or becomes damp, it must be baked at 60 ± 5 ℃ for 12 hours.

The electrode surface of the product is gold-plated, which is prone to corrosion or discoloration, making welding difficult. It is recommended to use it as soon as possible.

Be careful to avoid rapid changes in environmental temperature, especially in humid environments.

Electrostatic protection:

High brightness blue, green, and white products are sensitive to static electricity. When using them, it is important to note that static electricity surges can damage or destroy the product. For workbenches that come into contact with the product, please use conductive pads to ground through a resistor; The tip of the soldering iron must be grounded; Recommend using an ion generator.