the problem of shelf life is rarely encountered in ultra-high voltage ceramic capacitors. however, such things still happen. because such products are often customized according to requirements, there is little chance of long-term inventory. but occasionally there will be a kind of situation: production of mantissa inventory. for example, if the customer has ordered 1000 capacitors, the actual production is 1020. then 20 of them may be in stock until the next order is needed. however, these products are often not universal and are customized according to requirements. so, if the old user does not place an order, it is difficult to sell. this saves the next order cycle.
so, how long does it take to save the deadline?
in fact, if the user has two or three orders in a year, this problem is basically not to worry. because the ultra-high voltage capacitor period is different from the low-voltage ceramic capacitor, if the low-voltage ceramic capacitor period is not used for one and a half years, it will gradually discharge. the ultra-high voltage ceramic capacitor has a large voltage, and the crystal structure inside is not very stable, so it takes a long period of self-recovery period. the new off-line ultra-high voltage capacitor is in stock. after one to three months, the quality is the most stable. this time, the function is best.
however, it does not mean that the longer the self-recovery time, the better. if it is still useless after one year, it may start to show the same phenomenon as the leakage current is too large. therefore, the manufacturer should regularly do the charge and discharge test during the storage period, every three times. doing a charge once a month, this is the most reliable.