# Doubt ceramic smd capacitor **URL:** \ **Category:** Capacitors\ **Created:** [July 15, 2024, 8:50pm UTC](https://forum.digikey.com/t/doubt-ceramic-smd-capacitor/43222 "2024-07-15T20:50:51Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![Verna\_1353](https://avatars.discourse-cdn.com/v4/letter/v/fbc32d/32.png) [@Verna\_1353](https://forum.digikey.com/u/Verna_1353)\ **Post date:** [July 16, 2024, 12:45am UTC](https://forum.digikey.com/t/doubt-ceramic-smd-capacitor/43222/4 "2024-07-16T00:45:58Z")
The document David provided is very good and does answer the questions you are asking for capacitor aging. We have topics already on the Forum about this. Here is a link to another post: > [@Ceramic Capacitor Aging](https://forum.digikey.com/t/ceramic-capacitor-aging/4078): > > [Kemet](https://www.digikey.com/en/supplier-centers/k/kemet) recently came out with a new paper on Ceramic Capacitor Aging and I wanted to share some information on the key topics of Aging, Aging Rate and Deaging. Capacitor aging is a change in capacitance at a constant rate over time. Aging is generally expressed as a percentage per decade hour. Matt R has a great post that explains the [decade hour](https://forum.digikey.com/t/ceramic-capacitor-aging-what-is-a-decade-hour/1170). To help with aging calculations, Kemet has created a [Ceramic Aging Calculator r1.xls](https://forum.digikey.com/uploads/short-url/rZ0fRSj48dqqgoF162tTkZoc2D6.xls) (185 KB) Capacitance testing and aging is a topic that causes … > [@Ceramic Capacitor Aging / What is a Decade Hour?](https://forum.digikey.com/t/ceramic-capacitor-aging-what-is-a-decade-hour/1170): > > Ceramic capacitors lose a portion of their capacitance value over time as a function of their construction. This loss cannot be avoided, but it can be measured and specified. Manufacturers often use the decade hour as a unit of measurement for this loss. As an example, let’s examine KEMET part number [C1210C106K4RACTU](https://www.digikey.com/en/products/detail/kemet/C1210C106K4RACTU/2216501). This is a 10uf part with an X7R temperature coefficient. Kemet specifies this part to be within its design tolerances for a specific time window after reflow, and uses the dec… It seems like every supplier of ceramic capacitors talks about aging . They are really the same type of information as the Kemet PDF provided. Hopefully this helps. --- _[View the full topic](https://forum.digikey.com/t/doubt-ceramic-smd-capacitor/43222)._