How to choose high quality outdoor full color SMD lamp beads?

In order to verify the performance of these two aspects, Shanghai Super Silicon Group (AST) high-end SMD product research center selects the outdoor SMD products of many manufacturers currently on the market, and carries out reliable testing through strict outdoor environment simulation detection and service life detection. Detection of both aspects of sexuality and performance. The test results are mixed. Only the outdoor full-color SMD series products developed and produced by Shanghai Super Silicon Group (AST) can pass the whole process test. Now we will use the test process and results as a reference to share a set of criteria for identifying and selecting high quality outdoor full color SMD lamp beads.

First, how to ensure the high reliability of outdoor full-color SMD lamp beads?

1. What are the links in the use of LED lamp beads ?

The high reliability of LED lamp beads means that they can maintain the stability of quality during the whole process of the customer's use. The use of LED lamp beads is roughly divided into several links. The first is the factory inspection link. After passing the final visual inspection and electrical performance test in the production factory, the packaging is shipped. Secondly, it is the transportation and storage link. After the transportation and storage, it can reach the display factory; then the production and processing links. The factory opens the package and completes the production and processing of the finished display products through the production process such as upper plate and welding; the final is the normal use. In this whole process, the LED lamp bead must work reliably, and no dead light phenomenon can occur. During this period, the LED lamp bead should be able to withstand the effects of tidal expansion and temperature shock, especially the welding temperature shock of up to 260 degrees. The LED lamp bead is composed of a variety of different materials, such as metal copper, resin, PPA, conductive adhesive, light-emitting chip, etc., their moisture absorption coefficient and temperature expansion coefficient are different, so the material between them Coordination is quite critical, and if there is a mismatch, a dead light will appear. Therefore, it is necessary to judge the reliability of the LED lamp by using it. The following is an LED reliability model established by us to learn from the integrated circuit simulation model of the semiconductor industry.

2. How to simulate the transportation, storage and online links of customers?

Take a certain amount of product and evaluate the test results after the following experiment.

• 120-degree 24-hour baking: The goal is to remove residual moisture effects and prepare for the simulation experiment.

• 5 cycles of high and low temperature shock: The purpose is to simulate the temperature shock during transportation and storage after delivery. The high and low temperature selection is based on the product grade.

• Anti-moisture test stored in a temperature and humidity environment: the purpose is to simulate the moisture resistance of the product before leaving the factory. Temperature, humidity and time are determined by the product's resistance to moisture.

• Reflow soldering 3 times maximum temperature 260 degrees: the purpose is to simulate the welding process.

• The test requires that the product does not have a problem with electrical performance.

Reflow soldering conditions:

Remarks: The above only simulates the production process of the PCB on the product and has not involved the product use process, but has already faced two temperature and humidity selection problems.