Nitrogen cabinet is to regulate nitrogen injection into the cabinet, and achieve dehumidification and oxidation prevention. Nitrogen cabinet is widely used in semiconductor factory, crystal oscillator factory and precision component factory. It is mainly used for moisture-proof and oxidation protection. For the factory, the moisture-proof and anti-oxidation preservation of these precision parts plays an important role in the yield of production to ensure the quality.
In the normal use of nitrogen cabinet, how to evaluate its performance, due to technical constraints, users are generally reading the humidity of nitrogen cabinet distinguish. When evaluating the performance of nitrogen cabinet, users often find the humidity is difficult to drop down, can not meet the set standard. What is the cause of this situation? The following is the analysis.
The working principle of nitrogen cabinet is to fill the cabinet with nitrogen, gradually replace the original air in the cabinet, and then achieve a relatively anaerobic and dry storage environment. If the humidity of the nitrogen cabinet is not up to standard, the moisture-proof and oxidation-proof effect of the storage items in the cabinet will decrease. Nitrogen cabinet humidity can not meet the requirements, that is, the concentration of nitrogen in the cabinet can not meet the requirements. For a limited sealed cabinet, its concentration can not reach, only “air intake” and “air outlet” two reasons.
“Air outlet” represents the sealing of the cabinet, partial filled-in nitrogen leak out . When the leakage is too large, the nitrogen concentration in the cabinet will be lower, and the humidity will be low, and it will not be able to protect against moisture and oxidation.
The “intake air” represents the insufficient amount of nitrogen in the nitrogen cabinet In the process of using the nitrogen cabinet, due to the frequent opening of the cabinet door, the amount of nitrogen escaping from the switch door is larger than the amount of nitrogen filled into the cabinet, and the expected nitrogen concentration can not be reached.
The solution is divided into two parts, one is the sealing of the cabinet, the other is the increase of air intake. Manuifacturers should avoid sealing problems, and intake valve failure in the N2 cabinet.