Method for providing hermetic electrical feedthrough

A method of fabricating a hermetic electrical feedthrough, the method comprising:

• providing a ceramic sheet, and having an upper surface and a lower surface, wherein said sheet includes silicon dioxide;
• forming at least one via hole in said sheet extending from said upper surface to said lower surface;
• inserting a conductive thickfilm paste, including platinum, into said via hole;
• laminating said sheet with said conductive thick film paste in said via hole between an upper ceramic sheet, and a lower ceramic sheet, to form a laminated substrate wherein said via hole is encased in ceramic;
• selecting an oxygen controlled environment, between 10−38 and 10−3 atmospheres of oxygen partial pressure, by introduction of other gasses selected from the group consisting of C02/CO, C02/NH3, C02/H2, H20/H2, H20/NH3, H20/CO, Nitrogen, or Argon, to balance platinum oxidation and silicon dioxide decomposition of said laminated substrate;
• firing said laminated substrate in said oxygen controlled environment to a temperature to sinter said laminated substrate to form a single sintered structure and cause said conductive thick film paste in said via hole to form a metallized via, including platinum in contact with ceramic, and cause said laminated substrate to form a fired laminated substrate and a hermetic seal around said metallized via;
• and
• removing said upper sheet material and said lower sheet material by lapping or grinding, to expose an upper and a lower surface of said metallized via.