Updated: December 3rd, 2021

Five Reasons to Consider Polycrystalline Ceramic Seals Instead of Glass Seals for Hermetic DC Connectors

Rick Kalkowski, Marketing Administrator, PA&E, a Division of Hermetic Solutions Group

Advancements in materials give designers new options. Even classic designs such as the venerable DC connector can be updated and improved by considering all available materials. Switching from glass to polycrystalline ceramic brings advantages to hermetic seals and influences other elements of the design, ultimately leading to better performance. 

1.  More Pin Material Options

The glass sealing process for hermetic DC connectors requires the use of extremely heat-resistant pin materials that can survive the melting temperature of glass fully intact, and Kovar, a ferrous nickel/cobalt alloy, is one of the most popular. Polycrystalline ceramics seal at a lower temperature than glass, which accommodates the use of copper alloy pins, such as beryllium copper and chrome copper, as well as platinum, platinum clad, or Inconel pins.

Yellow ceramic-to-metal seals surround high-reliability BeCu pins in a hermetic Micro-D connector.

Figure 1: Yellow ceramic-to-metal seals surround high-reliability BeCu pins in a hermetic Micro-D connector.

2. Higher Electrical Conductivity