hermetic sealing of glass and metals

[m1ckvb]

I have a few questions about problems with hermetically sealing glass to metal. What tolerances should be applied for initial spacing between the glass and the metal? What is the best method to prevent the glass from cracking? How important is the furnace temperature in the sealing process? What causes the glass to crack in the sealing process and what should be done to prevent this from happening?
Thank you!

 

[hacksaw]

there are special glasses for that purpose, glasses that have solved most of the issues you,ve raised

 

[metman]

Also there are alloys with low CTE to provide a closer match with CTE of glass.

Jesus is THE life,
Leonard

 

[IRstuff]

While the materials approch is a way. Conventional glass and stainless steel have been worked into vacuum Dewars for infrared detectors. Some of the Dewar suppliers might be able to help you.

TTFN

 

[arunmrao]

Invar is mot often used for glass sealing purposes due to its nil CTE property.