Author Topic: Question smd ceramic capacitor  (Read 2150 times)

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Offline tiago1986

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Question smd ceramic capacitor
« on: November 25, 2021, 01:33:04 pm »
Do small portable electronic devices that use ceramic or tantalum SMD capacitors also need to be used constantly because they have the same problems as long-term stored electrolytic capacitors?
 

Online wraper

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Re: Question smd ceramic capacitor
« Reply #1 on: November 25, 2021, 01:42:18 pm »
No. Electrolytic capacitors should be powered once in a while to prevent insulating aluminum oxide layer from thinning, which may cause excessive leakage current when the voltage is applied after long period without voltage applied. There is no such degradation process with other types of capacitors.
 

Offline tiago1986

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Re: Question smd ceramic capacitor
« Reply #2 on: November 25, 2021, 02:07:11 pm »
in electrolytic capacitors after how long stored does it need to be powered? varies a lot from brand, age of the electrolytic capacitor (beginning of the 90's) and soldered in electronic circuit?

the same is not necessary in ceramic smd, tantalum, polyester
 

Online wraper

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Re: Question smd ceramic capacitor
« Reply #3 on: November 25, 2021, 02:25:56 pm »
in electrolytic capacitors after how long stored does it need to be powered? varies a lot from brand, age of the electrolytic capacitor (beginning of the 90's) and soldered in electronic circuit?

the same is not necessary in ceramic smd, tantalum, polyester
There is no fixed time, and you won't be able to tell from a datasheet how fast they will degrade. If you power for a few hours in a year or two, they should be fine.
 

Offline tiago1986

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Re: Question smd ceramic capacitor
« Reply #4 on: November 25, 2021, 03:31:30 pm »
normally I turn them on 1 hour is enough for the total reform of the electrolytic capacitor? I don't know if I use them every month to reduce failures in electrolytic capacitors from the 90's and mounted in electronic circuit
 

Offline Faringdon

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Re: Question smd ceramic capacitor
« Reply #5 on: November 29, 2021, 08:45:35 pm »
There must be loads of electrolytic capcaitors that get produced, and then end up in storage for 3 years or more, before getting sold.....and they dont have the dates on them, so they probably get sold  as though they were knewly made.
...But you dont hear about products blowing up at switch on....so i actually wonder if this is a ruse by the El cap industry, to get more sales of el caps.

I think you do get higher leakage at switch on if theyve been stored for 3 years plus.....but i suspect that with modern el caps, the leakage still  isnt that much...and after half an hour its died down to almost  nothing.
If this leakage current problem was genuine, then you'd have youtube videos of people putting voltage on a 3_year_old plus el cap, and showing its temperature going sky high....but there is no such video.
 


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