Electrically conductive vias and methods for producing same
An electrical component is provided by metallizing holes that extend through a glass substrate. The electrical component can be fabricated by forcing a suspension of electrically conductive particles suspended in a liquid medium through the holes. The suspension can be forced into the holes under an air pressure differential such as a vacuum force, a centrifugal force, or an electrostatic force. The liquid medium in the holes can be dried, and the particles can be sintered. The particles can further be packed in the hole. Alternatively or additionally, the particles can be pressed against the outer surfaces of the substrate to produce buttons.
1 . A method of metalizing a hole that extends in a substrate from a first surface to an opposed second surface, the method comprising the steps of:
introducing a first final fill into the hole at a first side of the substrate, such that the first final fill extends from the second surface toward the first surface, wherein the first side of the substrate defines the first surface;
introducing a bulk fill into the hole at the first side of the substrate, such that the bulk fill extends from the first final fill toward the first surface; and
introducing a second final fill into the hole at the first side of the substrate under one of an air pressure force, a centrifugal force, and an electrostatic force, such that the second final fill extends from the bulk fill to the first surface,
wherein the first final fill and the second final fills have respective average particle sizes that are each smaller than an average particle size of the bulk fill.
2 . The method as recited in claim 1 , wherein the introducing steps comprise introducing the first final fill, the bulk fill, and the second final fill as respective particles suspended in a liquid medium, and evacuating the liquid medium.
3 . The method as recited in claim 2 , further comprising the step of isostatically pressing the particles at least one of the first final fill, the bulk fill, and the second final fill.
4 . The method as recited in claim 2 , further comprising the step of sintering the particles after the final introducing step.
5 . The method as recited in claim 2 , wherein the particles of first final fill extends from the hole onto the second surface, and the particles of the second final fill extends from the hole onto the first surface.
6 . The method as recited in claim 5 , further comprising the step of hard pressing particles of the first and second final fills against the second and first surfaces, respectively, so as to define a button.
7 . The method as recited in claim 1 , wherein the first final fill is introduced into the hole under one of an air pressure force, a centrifugal force, and an electrostatic force.
8 . The method as recited in claim 7 , wherein the bulk fill is introduced into the hole under one of an air pressure force, a centrifugal force, and an electrostatic force.
9 . The method as recited in claim 1 , wherein the bulk fill is introduced into the hole under one of an air pressure force, a centrifugal force, and an electrostatic force.
10 . The method as recited in claim 1 , wherein the average particle size of the bulk fill is from approximately 5 to approximately 20 times the respective average particle size of each of the first final fill and the second final fill.
11 . The method as recited in claim 1 , wherein the respective average particle size of each of the first final fill and the second final fill is in a range from approximately 0.01 micron to approximately 1 micron.
12 . The method as recited in claim 11 , wherein the respective average particle size of the first final fill is substantially equal to the respective average particle size of the second final fill.
13 . The method as recited in claim 11 , wherein the average particle size of the bulk fill is in a range from approximately 1 micron to approximately 10 microns.
14 . The method of claim 1 , wherein the first and second final fills define respective hermetically sealed end caps.