Method and apparatus for providing hermetic electrical feedthrough

A method of forming multiple hermetic electrical feedthroughs comprising the sequential steps of:

• forming multiple intermediate blind holes in an unfired sheet of ceramic material, each hole extending from an upper sheet surface to a hole floor spaced from the lower surface of said sheet;
• inserting a wire into each hole so that the lower end of each wire is supported on a hole floor;
• firing said sheet and wires to sinter and shrink said ceramic material to form a hermetic compression seal around each wire;
• and
• removing ceramic material from said sheet lower surface to said hole floors to expose the lower ends of said wires thus forming through holes containing said wires.

A method of fabricating a hermetic electrical feedthrough comprising:

• providing an unsintered ceramic sheet having upper and lower surfaces;
• forming one or more intermediate blind holes in said ceramic sheet extending from said upper surface toward said lower surface;
• inserting a wire in each of said one or more blind holes;
• firing said sheet and wire to a temperature sufficient to sinter the sheet material and cause it to form a hermetic compression seal around said wire;
• and
• removing sufficient sheet material from said sheet lower surface to expose said wire thus forming a through hole containing said wire,
• wherein said firing occurs by ramping up to a first temperature at a first heating rate;
• then ramping up to a second temperature higher than the first temperature at a second heating rate different from the first heating rate.