# Testing High Capacitance MLCC’s **URL:** \ **Category:** Capacitors\ **Tags:** ceramic-capacitors, tech-tips\ **Created:** [August 8, 2017, 5:00am UTC](https://forum.digikey.com/t/testing-high-capacitance-mlcc-s/34 "2017-08-08T05:00:00Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Robert\_Fay](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/robert_fay/32/6529_2.png) [@Robert\_Fay](https://forum.digikey.com/u/Robert_Fay)\ **Post date:** [August 8, 2017, 5:00am UTC](https://forum.digikey.com/t/testing-high-capacitance-mlcc-s/34/1 "2017-08-08T05:00:00Z")
Most LCR meters are incapable of testing high value MLCC’s due to their internal impedance. The impedance of all MLCC’s 1.0uF and higher is so low at 1KHz that the supplied current of the meter is essentially drained, in-turn dropping the specified voltage to basically 0 Volts so the capacitor never sees the required voltage. This can be verified by measuring the voltage across the capacitor while it’s under test with a true RMS meter. If the voltage is less than 0.4Vrms, the capacitance reading will be low every time. Some mid-range LCR meters have an impedance matching capability ALC (Automatic Level Control) Function. This allows the meter to decrease its own impedance until it’s lower than the device under test. However, in the case of most high value MLCC’s, this alone is not enough. With these caps, an amplifier unit is necessary to increase the current through the capacitor until the voltage across it reaches the pre-set level (.5Vrms – 1Vrms). We have an Agilent 4284A machine here at Digi-Key and it has both of these capabilities. There could also be an issue of aging with these caps, however you want to ensure that you are testing them correctly before trying to correct any aging issue. Here is a excellent article from Steve Maloy that also talks about aging with the MLCCs. > **[What is the Capacitance of this Capacitor?](https://www.digikey.com/en/articles/what-is-the-capacitance-of-this-capacitor)** > > An explanation of MLCC dielectric aging and how TDK compensates for this natural phenomenon in a question and answer format. We also have another great article from Mark Waldrip and Richard Tse at TDK that dives into Capacitance Measurement [http://www.digikey.com/en/pdf/t/tdk/capacitance-measurement](http://www.digikey.com/en/pdf/t/tdk/capacitance-measurement) An LCR meter is a meter or electronic test equipment used to measure the inductance ( **L** ), capacitance ( **C** ), and resistance ( **R** ) of an electronic components. Here is a short video from Kemet that helps show how you can use you LCR to get accurate reading when testing your Class 2 MLCCs. [![](https://global.discourse-cdn.com/digikey/original/3X/9/2/92e92e6203fe742ba0e91e6016fa828157fe422a.jpeg "Finding the Most Accurate Capacitance Measurement") ](https://www.youtube.com/watch?v=JJpW_O_vMzw) **See also** : [MLCC Common failure issue: Flex Cracking post](https://forum.digikey.com/t/mlcc-common-failure-issue-flex-cracking/572) [Why ceramic capacitors may seem out of spec but aren’t](https://forum.digikey.com/t/why-ceramic-capacitors-may-seem-out-of-spec-but-aren-t/892) ---
**Author:** ![Aron\_Muetzel](https://avatars.discourse-cdn.com/v4/letter/a/3ec8ea/32.png) [@Aron\_Muetzel](https://forum.digikey.com/u/Aron_Muetzel)\ **Post date:** [September 22, 2017, 2:03pm UTC](https://forum.digikey.com/t/testing-high-capacitance-mlcc-s/34/2 "2017-09-22T14:03:16Z")
Also from TDK this is a great video showing high capacitance measurement and techniques [https://www.digikey.com/en/videos/t/tdk/high-capacitance-capacitor-measurement-tutorial-by-tdk](https://www.digikey.com/en/videos/t/tdk/high-capacitance-capacitor-measurement-tutorial-by-tdk) . ---
**Author:** ![Ryan\_2724](https://sea2.discourse-cdn.com/digikey/user_avatar/forum.digikey.com/ryan_2724/32/1716_2.png) [@Ryan\_2724](https://forum.digikey.com/u/Ryan_2724)\ **Post date:** [April 5, 2019, 8:36pm UTC](https://forum.digikey.com/t/testing-high-capacitance-mlcc-s/34/3 "2019-04-05T20:36:22Z")
**See also aging from Johanson Dielectrics Inc.:** > **[Ceramic Capacitor Aging - Johanson Dielectrics | DigiKey](https://www.digikey.com/en/pdf/j/johanson-dielectrics/ceramic-capacitor-aging)** > > Class II and IV dielectrics experience a phenomenon called aging, and it is simply a decrease in capacitance over time due to crystalline changes that occur in all Class II and IV dielectrics (X7R, X5R, and Y5V). “After the soldering process, the capacitors have essentially been De-Aged. Capacitance measurements may be erratic in the initial 10 hours after testing. This is due to the initial capacitance value, dielectric type and the time between reflow and the capacitance measurement. For this reason, it may be necessary to wait for the capacitance to stabilize after reflow before testing. In “High K” dielectrics, the capacitance may also appear slightly high after the soldering process. This is normal as the capacitance is intended to be stable after 1000 hours so that there is adequate capacitance throughout the life of the circuit.” Here is an additional post that may be helpful. > [@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…