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As the development of LED photoelectric industry, the requirements of the industry are becoming more and more strict. surface mount devices (SMDs) are usually moisture sensitive elements, and atmospheric moisture penetrates into the packaging material through diffusion. When the SMD element is welded to the circuit board, the process is to pass it through the reflow welding with a temperature of 150℃-260℃, and at high temperature
, the rapid expansion of the moisture that seeps into it
produces enough steam pressure damage or destroys the LED element, resulting in
reliability failure problems such as internal rubber crack, delamination or
gold wire damage. For avoiding the reliability failure caused by moisture
absorption, the storage and moisture-proof measures before welding of LED
products should be done well.
In the past, humidity cards were usually used to test their
humidity situation, not only cumbersome, but also the humidity tested is not accurate.
now recommend moisture-proof box or drying box to meet the requirements of
dehumidification and drying. LED silver plating bracket, driving chip,
epitaxial chip and so on need to be stored in nitrogen cabinet to prevent
oxidation.
The moisture-proof box can store the items in the
relatively closed and dry box to form a moisture-proof and anti-oxidation
environment to prevent moisture absorption, moisture hydrolysis and oxidation.
The moisture-proof box absorbs water molecules through a molecular sieve
composed of high-efficiency hygroscopic polymer materials, and uses the “shape
memory alloy” system dehumidification method to control the internal and
external doors for moisture absorption and dehumidification circulation.
Finally, the water molecules in the moisture-proof box will be discharged out
of the cabinet. In the whole process, the water molecules will always remain
gaseous and will not produce the heat absorption process.
