Product category:
Capacitors
News Release from: HolyStone (Europe) | Subject: X7R multilayer ceramic capacitors
Edited by the Electronicstalk Editorial
Team on 18 February 2008
Multilayer ceramic capacitors avoid
flashover
Innovative arc prevention coating process covers the surface of the dielectric without encroaching onto the termination material.
Holy Stone has come up with components industry's first commercial solution to surface arcing, or flashover, on X7R multilayer ceramic capacitors An innovative arc prevention coating process covers the surface of the dielectric without encroaching onto the termination material
This article was originally published on Electronicstalk on 8 Nov 2004 at 8.00am (UK)
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This creates a nonporous surface that prevents moisture and dirt being trapped, thereby reducing the surface resistance and arcing voltage of the capacitor.
According to Clive Youngs, Technical and Applications Manager of HolyStone Europe: "Surface arcing or flashover is increasingly a problem as high-voltage X7R multilayer ceramic capacitors become more popular in applications such as power supplies, telecommunications, industrial equipment and modems".
"It can cause equipment failure during isolation testing and also may leave a carbon track on the surface that can make the capacitor fail".
"The new arc prevention coating is the first ever cost-effective solution to this problem, and we are confident it will prove a revolutionary development".
"Extensive testing has shown that arcing voltage of unsoldered capacitors is increased by approximately 30%".
Youngs continues: "More importantly, the arc prevention coating aids cleaning of the capacitor's surface post-soldering, making any flux or dirt residues easy to remove using standard cleaning processes".
"Due to the open and porous nature of the X7R dielectric surface, moisture and dirt - which has a lower resistance than dielectric grains - can become trapped in the surface".
"As well as becoming embedded into the surface itself, this material will attract additional moisture onto the surface, so reducing both surface resistance and the voltage at which arcing occurs".
Tests have shown that the arcing voltage on soldered capacitors can be increased by up to 65% using the company's arc prevention coating.
Typical results for an 1808 X7R soldered capacitor after cleaning show that arcing voltage increases from 2200V DC for an uncoated part to 3600V DC for a coated capacitor.
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