Nitrogen cabinet, also known as nitrogen drying cabinet, and electronic moisture-proof box is called moisture-proof box. In LED packaging, they both have the common feature of moisture-proofing. The difference is that the moisture-proof box can only prevent moisture, but cannot prevent oxidation, while nitrogen cabinet can prevent both moisture and oxidation. In addition, the humidity control of the moisture-proof box can reach below 5% RH, which ordinary nitrogen cabinets cannot achieve. In LED packaging, they need to be reasonably matched according to actual needs.
The nitrogen gas cabinet is filled with nitrogen, which is generally divided into bottled high-concentration liquid nitrogen and nitrogen generated by the nitrogen tower. The lowest humidity of these two types of nitrogen can reach 15% RH. That is to say, the humidity of ordinary nitrogen gas cabinets cannot reach below 10%. Nitrogen cabinet can squeeze out oxygen by injecting nitrogen, thus forming an inert gas protective environment to prevent the oxidation of stored wafers, IC chips, and LED chips. The moisture-proof box is actually a dehumidification cabinet and drying cabinet, which removes water molecules from the box to form a low-humidity environment to prevent LED chips from getting damp. The moisture-proof box is a humidity control device that can control humidity to below 5% RH to prevent products from becoming damp. From the above data comparison, the moisture-proof box has true humidity control ability, while the nitrogen gas cabinet has no humidity control ability and mainly depends on the humidity of nitrogen. If the humidity of the gas source is high or the nitrogen production tower fails, the humidity in the nitrogen gas cabinet may even soar to 50% RH.
The nitrogen cabinet uses inert gas to protect the environment and squeeze out oxygen to avoid the production of oxidizing environment. Oxidation is difficult to occur in an anoxic or low-oxygen environment at room temperature. Moreover, the products put into the nitrogen cabinet are basically moisture-proof vacuum packaging, so oxidation can be avoided. The moisture-proof box can only control humidity and cannot control the oxygen content. The oxygen content is almost at normal oxygen levels, so oxidation is still highly likely to occur. From the above comparison, the nitrogen cabinet can prevent oxidation, while the moisture-proof box cannot.
The application of nitrogen cabinet and moisture-proof box in LED packaging depends on the process requirements. If moisture-proofing is required, nitrogen cabinet or moisture-proof box can be selected according to specific humidity requirements. However, using the moisture-proof box is more secure, but it is best to combine it with nitrogen to accelerate dehumidification. If humidity requirements are extremely strict, moisture-proof boxes must be used. If oxidation resistance is required, nitrogen cabinets must be used. If both are required, then both need to be used together, and a moisture-proof nitrogen cabinet should be selected.