Dave Jones from EEVblog released a video of his investigation into x class safety film capacitor failures.
In this practical case he managed home-made teardown and invite Ron Demcko, KYOCERA-AVX capacitor expert for explanation of the failure type observed.
You might think you know how film capacitors fail and degrade in capacitance over time – self-healing due to surges, right? WRONG! Capacitor expert and KYOCERA-AVX Fellow Ron Demcko confirms what’s really going on after a teardown of some failed and one good polypropylene X class safety capacitor.
- 00:00 – Teardown of a some failed film capacitors
- 00:52 – Self Healing and drop in capacitance
- 01:44 – Capacitance Measurements
- 02:15 – Teardown of a new Suntan brand polypropylene X2 film capacitor
- 03:03 – Different failure modes based on size and winding pressure
- 05:52 – Unwrapping the film
- 07:51 – The film inside a NEW film capacitor
- 09:19 – Teardown of the FAILED uTx brand heater capacitor with half capacitance
- 10:06 – How Schoopage and the end pin terminations work
- 12:23 – Teardown continues…
- 12:45 – WOW! What on earth is this?
- 14:54 – Elecami Wolf also did a teardown
- 16:05 – Teardown continues…
- 17:01 – Separating the film showing both slef-healing and extensive metal film corrosion
- 18:29 – Another uTx brand failed film capacitor from a Corsair PSU, with 90% loss in capacitance! Elecami Wolf Youtube Channel: https://www.youtube.com/c/ElecamiWolf
- 19:55 – Let’s call an expert! Ron Demcko from KYOCERA-AVX tells us the REAL REASON for the failure! It’s moisture ingress and corona demetallization!
Full discussion with Ron Demcko: https://www.youtube.com/watch?v=9V99J…
Film Capacitors Passive Components Knowledge Blog Links:
- Film Capacitors construction: https://passive-components.eu/capacitors-electrostatic-constructional-solutions/
- Film Capacitors self-healing explanation: https://passive-components.eu/capacitors-electrostatic-constructional-solutions/3/#split_content
- Film Capacitor types: https://passive-components.eu/film-and-foil-organic-dielectric-capacitors/
Metallized Film Capacitor Lifetime Evaluation and Failure Mode Analysis report: https://cds.cern.ch/record/2038610/fi…
Forum: https://www.eevblog.com/forum/blog/ee…!
