LED 3528 SMD soldering on PCB board Is it better to heat solder or reflow soldering Please explain t

Reflow soldering should be good, the damage to LED should be small, the temperature change curve of reflow soldering is set according to the optimal temperature change curve of LED, which can prevent the instantaneous temperature change from being large and causing the instantaneous shrinkage or expansion between LED PPA and the metal to produce defects, I personally think that reflow soldering is better than heating soldering, which only represents my personal opinion.

Can you explain the heat welding process? I haven't heard of the heat soldering process, and the most commonly used ones are reflow soldering and wave soldering.

LED patches are suitable for reflow soldering. Wave soldering involves rolling the part in a solder pot to reach the pad contact with the tin. The temperature in the tin pot is about 260 degrees, and the temperature resistance of LED parts should not reach such a high temperature, which will cause damage to the parts.

Of course, you can also check the specifications of the parts yourself to see if its temperature resistance can be met, as long as the temperature resistance is satisfied, any process can be used.

First of all, you have to see how big your amount is, if the amount is very small, you can choose the heating platform, so that the lamp beads can buy a cheaper kind, if the amount is very large, you must buy reflow soldering, reflow soldering to choose hot air so that it is not easy to die lamp, I use the HN-8800 hot air reflow soldering of Shenzhen Rio Tinto Technology, with the glue used to encapsulate the lamp beads that are mainly seen, one is not resistant to high temperature, only the heating platform can be used, and the other is high temperature resistant to reflow soldering, and the high-power lamp beads of reflow soldering are about 4 cents more expensive.

The question is unprofessional, so how do we ???

1.Your engineering analysis has a certain truth, and it is not impossible;

2.The main thing is damp, after the LED is damp, once it is reflowed, the metal bracket will be blackened by high temperature.

3.Please be careful to find out the cause of moisture and improve it. Special attention should be paid to the fact that LEDs should not be exposed to air for a long time, 4Solution: Dry the stock LEDs in advance before use. (Please pay attention to the baking temperature and time).

It has little to do with silica gel, and it has to do with the quality of the LED lamp itself, and black spots will appear if the LED heat dissipation is uneven. You can do a long-term test, the LED temperature will turn black after a certain temperature, 3528 LED has a lot of quality problems, find a good manufacturer, you can ask the manufacturer. The LEDs we use are all produced by Huizhou Huayang.

You ask your LED supplier to give you a copy of the product information, which should have the time of LED reflow soldering and the optimal temperature curve, etc., and then check whether there is a problem with the temperature and time of the reflow soldering setting. After the reflux, the most common is that the lamp beads are yellow, and it is not normal to appear black, and the results I analyzed are 4: 1. The reflux time is too long; 2. The reflow temperature is too high; 3. The anti-aging ability of lamp bead material is too poor; 4. The voltage or current is too large when the test is carried out after reflow, which causes the local lamp beads to break down and burn.

I am an employee of Guangzhou Zhengda Magneto, when we do 3528 SMD lamp bead welding, we do not use an electric soldering iron, but a hot air blower and a low-temperature tin bar, only in this way, the temperature of the electric soldering iron is too high, resulting in silica gel melting.

Could it be caused by static electricity?

Shenzhen Tongchuangli: high brightness 3020, 20ma 8 lumens.

Can the resistance be a monument? The two sides of the solder paste are the same, mainly depending on whether the amount of solder paste is the same on both sides, and the temperature of the reflow soldering is uniform and uneven.

There are several reasons for the dead light:

1.When the glue is damp and reflowed, the water vapor evaporates, the glue expands, and the gold wire is torn off. (If it is vacuum packed, it generally does not need to be dehumidified for 7 days, because the package will be dehumidified for customers before shipment.)

If it is not vacuum packed, then the lamp beads need to be dehumidified before patching, generally 70 degrees, 12 hours).

2.The glue has a large coefficient of expansion. (You can consult the factory and ask for data and reports) 3

The chip electrode is dirty, soldered, or soldered. (The chip is dirty and needs to be dealt with by the chip manufacturer, if it is the virtual soldering of the equipment wire, it means that the equipment parameters of the factory have not been adjusted well.) ）

4.High-temperature welding is easy to cause dead lights. (It is generally recommended to use low-temperature lead-free solder paste for reflow soldering, and the reflow soldering temperature is not higher than 220 degrees).