Electric Field From Insulated Electrodes

Hi Shyam,

which thickness?, how much leakage current is allowed?

I have a sample of thin wire (less then 0.1mm diameter) insulated by near 3 µm glass.

This was fabricated 15 years ago in Russia.

In principle: any alloy will be good that has a matching temperature coefficient to a glass made for metal in glass feed-throughs.

As you will need a very good insulation quality I would try the glass that is used for H4 and H2 lighting bulbs used in cars.

Deposition may be best from Ethoxi-Silane and similar precursors with or without electrophoresis.

Any wire used for deposition shall be oxidised.

For a quick first test I would use wires that are loosely positioned inside quartz capillaries.

Have success!

RHABE

Dear RHABE,

I have these 1mm thick metal disk type electrode that are to be coated. Perhaps I will look into metal to ceramic bond for better selection. I can use SS Electrodes. I need some matching of temperature coefficient as electrodes to be heated to about 400C.

http://www.kemcointernational.com/SealingGlassRefGuide/ReferenceGuideSealingGlass.htm

http://www.teknaseal.com/

http://books.google.de/books?id=dZkTdPyZR64C&pg=PA630&lpg=PA630&dq=kovar+einschmelzglas&source=bl&ots=-aOAfV8cwN&sig=jc0jlCZFsRiBmFDsfDh8wBpob6U&hl=de&ei=heA9TLOvOc6jOIyl2bQP&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCgQ6AEwBQ#v=onepage&q=kovar%20einschmelzglas&f=false

Dear Shyam,

here are links to one list of suitable sealing materials, one company that should know how to and one copy of a book where the composition of the sealing glass that is suitable for sealing KOVAR is published.

A small company that is able and can deliver small quantities is to be found here:

http://www.hilgenberg-gmbh.com/en/products/custom-assembled-parts/

I would also think about ITO films without metallic parts and direct bonding by pressure and temperature or sodium or potassium local enrichment and bonding. These should be sufficient as you do not need any current (except capacitive and polarisation?).

Have success!

RHABE