With the development of LED display market, full-color SMD lamp beads will gradually become the future of outdoor display of the mainstream light-emitting devices. In the use of outdoor environment, SMD lamp beads to be stable use, must have high reliability and high performance of the two prerequisites. How to identify and select high-quality outdoor full-color SMD lamp beads? Is there a complete set of standards?
Full color SMD lamp beads advantage analysis:
Compared to the traditional straight oval lamp beads represented by 346, the SMD lamp beads have three advantages:
1. From the performance point of view, SMD lamp beads with a large angle, mixed light, good consistency and other advantages;
2. From the structural point of view, SMD lamp beads can be applied to all kinds of small spacing screen, and the choice of SMD lamp beads display light structure, easy to transport, installation;
3. From the production point of view, SMD lamp beads production and processing of a high degree of automation, processing accuracy is better, can greatly enhance the production efficiency.
First, how to protect the outdoor full color SMD lamp beads high reliability
1, LED lamp beads which is divided into several links?
LED lamp beads of high reliability is that it can in the customer's entire process of use, to maintain the stability of quality. LED lamp beads use, probably divided into so few links. The first is the transport storage links, after transport, storage and other links to reach the display factory; and then the production and processing links, the screen Plant to open the packaging, through the plate and welding and other production processes to complete the production and processing of finished products; the final use of the link. In the whole process, LED lamp beads must be reliable work, can not die dead phenomenon. During this period LED lamp beads to be able to withstand the tide and the impact of temperature and other tests, especially the maximum temperature of 260 degrees of welding temperature shock. The LED lamp beads are composed of a variety of different materials, such as metal copper, resin, PPA, conductive adhesive, light-emitting chip and other components, their moisture absorption coefficient of expansion and temperature expansion coefficient is different, so the material between them With a very critical, such as with the improper will appear dead lights. So you must simulate the use of LED lights to determine the reliability of the process. Here we learn from the semiconductor industry, integrated circuit simulation model, the establishment of the LED reliability model.
2, how to simulate the customer's transportation, storage and on-line links?
Take a certain amount of product through the following experiment to assess the test results.
① 120 degrees 24 hours baking: the purpose is to remove the residual moisture effects, as a simulation experiment preparation.
② cycle of high and low temperature shock: the purpose is to simulate the factory after the transport, storage temperature shock. The high and low temperature options are determined according to the product grade.
③ anti-moisture test in a certain temperature and humidity storage environment: the purpose is to simulate the factory to welding before the product moisture resistance. Temperature and humidity and time to have a product to prevent moisture level.
④ 3 times the maximum reflow soldering temperature of 260 degrees: the purpose is to simulate the welding process.
⑤ test requirements of the product does not have a performance problem.