SCHOTT Electronic Packaging, a division of international technology group SCHOTT AG, has developed a pioneering solution to mitigate electrolyte dry-out in capacitors for long-term and reliable high-level performance. Drawing on over 75 years of experience in glass-to-metal sealing (GTMS), the company is now introducing new capabilities to produce glass-to-aluminum (GTAS®) seals – the first of its kind.

Polymer materials are often used to seal capacitor terminals. The organic nature of polymers makes them susceptible to deterioration to a brittle state over time, resulting in loss of gas-tightness. Moisture is then able to permeate the compromised polymer seal, which causes electrolyte evaporation and significant losses in power capacity.

The solution to electrolyte leakage lies in the capacitor lids. Helmut Hartl, Head of R&D at SCHOTT in Landshut, Germany, explained the benefits of utilizing GTAS technology for capacitors: “By replacing seals made from polymers or other organic compounds with specialty glass materials, capacitor terminals can be hermetically sealed into the aluminum lids. Creating a completely gas-tight glass-to-aluminum sealed barrier at the pin seal points protects the capacitor from moisture intrusion, eliminating the potential for electrolyte dry-out.”

SCHOTT Capacitors

SCHOTT has developed a pioneering solution to mitigate electrolyte dry-out in capacitors for long-term and reliable high-level performance. Picture: SCHOTT

In addition to unprecedented support for capacitor reliability and longevity, GTAS technology offers nearly boundless customization possibilities. The leak-tight, glass-sealed lids are suitable for a wide range of applications, including radial, axial, snap-in, supercapacitors, and electric double-layer types – all in both small and large can sizes.

As a standard in many harsh environments, safety-critical applications for decades, hermetic glass seals offer a host of benefits beyond the prevention of electrolyte loss in aluminum capacitors. Glass-to-metal seals are capable of withstanding environments with temperatures of -40ºC to +150ºC without issue, and in some cases even farther beyond such a range. The leak-tight nature of glass seals allows for the development of standard size or even smaller units with much higher capacitance. This benefit also results in an increase in both shelf life and overall longevity of the capacitor.

Hartl shared his outlook on GTAS technology for capacitors: “This is an exciting period for capacitor development. We see every day the continued growth of next-generation power applications that rely on them, including electric vehicles and renewable energy sources. GTAS technology comes at a perfect time to support even more reliable, long-lasting electrical storage performance in sectors shaping the future of our day-to-day lives.”

Please view the video on "GTAS® Capacitor Lids – Leak tight lids for Aluminium Electrolyte Capacitors" technology below: