Solid high aspect ratio via hole used for burn-in boards, wafer sort probe cards, and package test load boards with electronic circuitry
View Patent ↗A method, and apparatus resulting from the method, for fabricating a circuit board suitable for mounting electronic components. The method includes drilling a plurality of through-holes in a plurality of dielectric sheets, forming a conductive film on at least one side of each of the plurality of dielectric sheets, and substantially filling each of the plurality of through holes with a conductive material. The conductive material is both electrically and thermally uninterrupted from a first face to a second face of each of the plurality of dielectric sheets. The plurality of dielectric sheets are then sequentially mounted, on atop another, to form the circuit board. The sequential mounting step is performed after the steps of drilling the plurality of through-holes, forming the conductive layer, and substantially filling the plurality of through-holes.
1. A probe card for mounting into an automated test equipment system, the probe card comprising a plurality of dielectric sheets, each of the plurality of dielectric sheets having a conductive film on at least one face thereof, the conductive film arranged to define electrical traces, each of the plurality of dielectric sheets further having a plurality of through-holes contained therein, the plurality of through-holes being substantially filled with an electrically conductive material, at least one of the plurality of filled through-holes of each dielectric sheet being aligned to define at least one via arranged to traverse the probe card and having an aspect ratio of least 50:1, wherein at least one of the conductive films intersects the via.
2. The probe card of claim 1 wherein the conductive material is copper.
3. The probe card of claim 1 wherein the conductive material is comprised of both titanium and tungsten.
4. The probe card of claim 1 wherein each of the plurality of dielectric sheets is comprised of an organic material.
5. The probe card of claim 1 wherein each of the plurality of dielectric sheets is comprised of a rigid material.
6. The probed card of claim 1 wherein one or more of the plurality of through-holes is arranged so as to form a blind via.
7. The probe card of claim 1 wherein one or more of the plurality of through-holes is arranged so as to form a buried via.
8. The probe card of claim 1 wherein at least one of the plurality of through-holes is arranged to traverse the probe card and has an aspect ratio of least 75:1.
9. A probe card configured for use with an automated test equipment system, the probe card comprising:
a plurality of dielectric sheets, each dielectric sheet having a plurality of through-holes contained therein, the plurality of through-holes being substantially filled with an electrically conductive material, at least one through-hole of each dielectric sheet being aligned to define a via that extends between opposing side surfaces of the probe card, the via having an aspect ratio of least 50:1;
a conductive film positioned on at least one face of each dielectric sheet, the conductive films defining electrical traces, at least one of the conductive films intersecting the via.