Salt spray resistance for hermetic glass-to-metal sealed housings
SCHOTT has now developed a special coating through which the industry’s salt spray requirements for hybrid housings can be exceeded. The coating protects glass-to-metal seals against corrosion, even after 24 hour salt spray tests. This improves the reliability of hermetic packages, especially for applications in extremely harsh environments, such as aerospace projects.
To achieve this high level of corrosion protection, SCHOTT uses corrosion-resistant materials. The packages are permanently protected because even if parts of the glass envelope break, only coated areas will be exposed. Thus, SCHOTT’s latest coating offers high corrosion resistance even after extremely aggressive 24 hour salt spray tests are performed.
“The corrosion protection offered by our new special coating does not impair the mechanical integrity of the glass-to-metal seal in any way,” explains Robert Hettler, Head of R&D for Opto-Electronics, SCHOTT Electronic Packaging.
Hermetically sealed hybrid packages that include glass-to-metal technology are used to encapsulate multi-chip modules in a wide variety of component manufacturing, such as sensors and components for measurement and in control electronics and MPUs. These devices are used in radar applications in aviation, laser warner systems and DC/DC converters, for example.
Permanently bonding glass and metal together is particularly challenging for most manufacturers because the thermal expansion coefficients of all the materials usually differ, so they must be perfectly matched.
"When advising our customers, SCHOTT engineers draw on our 70 years of experience in hermetically sealed enclosures and we can recommend and supply the best technology and high-performance combinations of materials,” Hettler said. “SCHOTT’s coating for hermetic glass-to-metal packages is another industry-leading technology, and devices treated with it will perform at their peak for longer.”
SCHOTT will present its product range from 8th to 10th September, 2015, at the European Microwave Week in Paris (booth 228).