LED is the basic component for the manufacturing of LED display panels, which are finally assembled into LED screens. As a humidity sensitive and vulnerable electronic, LED should be packaged to protect from the moisture in the environment, and carefully handled while the packaging procedures, and of course, aging of LED panels or LED displays should also be processed with care to avoid degrade of performance or failures happening on LED pixels. Now let’s follow the guidance of Kinglight LEDs and learn how to correctly use LEDs in packaging, maintain, and do the aging of LED displays.

 

I – Package

 

After LED packaging and QC testing procedures complete, LEDs will be well packed in a sealed bag to protect from being damaged before they reach the production lines for LED displays.

 

1. Generally, LEDs are packaged in vacuum aluminum foil bags with desiccant inside to absorb moisture and keep the LEDs in dry condition.

 

2. In addition, there will be a humidity indicator inside the vacuum aluminum foil bag, which indicates humidity at 6 different percentages, including 10%, 20%, 30%, 40%, 50%, and 60%; after opening the vacuum bag, read the indicator first, if it indicates that the humidity reaches 30% or even higher, the LEDs should be re-baked to get ride of moisture inside them. And of course, all LEDs are well baked before being packaged into a vacuum aluminum foil bag; this issue is usually because of a leakage in the vacuum bag caused by unexpected damage while transportation.

 

3. Before we do the surface mount procedures, we should also carefully check the label on the aluminum foil vacuum bag to identify the exact product ID, production batch, etc., to avoid mixed use of LEDs of either different product ID, or different bins, or different production batches, which can result in color display deviation among different LED panels.

 

Take the label on the aluminum foil vacuum bag of Kinglight LEDs for example, it usually states product ID, BIN, production batch, date, quantity, and product parameters, etc.

 

 

3-1. before use, carefully check above information and avoid using LEDs of different ID or bins to avoid color deviation among different LED panels; keep the labels or a record of used LEDs as a trace in the future.

3-2. LEDs of different product IDs can’t be used together.

3-3. LEDs of different production batches can’t be used together even though they have the same product ID and parameters.

 

II – Guidance of Surface Mount Procedures

 

Now, let’s proceed to the details we should care while doing SMT operations.

 

1. LEDs in unopened vacuum bags should be stored in environment under 30℃ and with humidity less than 60%RH, and must be used in 3 months.

 

2. Before opening the vacuum bag, check if there is a leakage; if so, return it to the manufacturer for re-bake. Remember, only dry LEDs can be used for SMT production

 

3. After the opening of vacuum bags, we should follow below tips while SMT production.

 

3-1. Welding of LEDs should complete in 12 hours.

3-2. Ensure that the temperature in the production workshop is below 30°C and the humidity is below 60%RH; and prevent contact with the outside world.

3-3. LEDs that have not been used for more than 12 hours need to be re-baked before use.

3-4. Unused LEDs must be stored in an environment with a temperature below 25℃ and a humidity below 30%RH and must be used within 24 hours.

 

Baking Conditions

 

This is only for LEDs that have been stored for a long time after opening. It is recommended that LEDs that have been exposed to moisture before opening be returned to the factory for re-baking.

Baking conditions include temperature and duration.

Note: The baking temperature error must be controlled within the range of ±5°C to ensure the baking effect and avoid damage to the LED.

 

4. LEDs should be immediately used after the vacuum bags are opened and it’s unnecessary to purchase LEDs if there is no production plan in a long period; avoid long time exposure of unused LEDs to the air, and store them in vacuum bags immediately, and re-bake them next time you’re using them.

 

5. LEDs shouldn’t be baked more than twice; repeated baking will affect auxiliary materials such as the material tray and carrier tape, and may cause material throwing, tape breakage, and wire drawing during SMT procedures.

 

6. Electrostatic discharge can damage the performance of LEDs; when performing SMT operations on LEDs, proper anti-static measures must be taken.

 

6-1. Operators must wear anti-static wrist straps, anti-static shoes or anti-static gloves, etc.

6-2. All mechanical equipment must be grounded.

6-2-1. The workshop needs to be paved with anti-static flooring and grounded, and use anti-static work mats;

6-2-2. Each machine equipment must be well grounded, and the AC impedance should be less than 1 ohm;

6-2-3. Regularly check whether the machine parameters and power output are qualified, and check whether the test equipment and drive power supply have leakage.

 

Continue to read:

Guidance for LED Application & Protection (II) >>>