Semiconductor device with inclined through holes
View Patent ↗A semiconductor device has a semiconductor substrate with an inclined through hole extending between its two major surfaces in a peripheral part of the substrate, providing an electrical interconnection between the two surfaces. The opening of the inclined through hole on the first major surface, on which electronic components are formed, is closer to the edge of the substrate than is the opening on the second major surface. Reliability is therefore enhanced because cracks forming at the edge of the second major surface are less likely to propagate to the through hole. An electrically conductive path in the through hole is formable by spraying conductive material onto its inner wall, using an ink-jet system.
1. A semiconductor device comprising:
a semiconductor substrate having a center of volume, a central axis passing through the center of volume, a first surface extending substantially orthogonal to the central axis, electronic circuitry formed on the first surface, a second surface extending substantially orthogonal to the central axis, an edge extending substantially parallel to the central axis from the first surface to the second surface, and a peripheral part inwardly adjacent to the edge, wherein:
the peripheral part has a through hole extending from the first surface to the second surface, the through hole providing an electrical connection between the first and second surfaces, the through hole originating at a first opening on the first surface and terminating at a second opening on the second surface, a distance of the second opening from the edge being larger than a distance of the first opening from the edge, a geometric projection formed by projecting the first opening onto the second surface parallel to the central axis being disposed partly inside and partly outside the second opening, the second opening being partly inside and partly outside the geometric projection.
2. The semiconductor device of claim 1 , wherein the through hole is inclined at an angle of at least twenty-five degrees with respect to the central axis.
3. The semiconductor device of claim 1 , wherein the through hole is inclined at an angle of at most forty-five degrees with respect to the central axis.
4. The semiconductor device of claim 1 , wherein the through hole has an inner diameter of at least thirty micrometers.
5. The semiconductor device of claim 1 , wherein the through hole has an inner diameter of at most fifty micrometers.
6. The semiconductor device of claim 1 , wherein the upper surface and lower surface of the semiconductor substrate are mutually separated by a distance of substantially fifty micrometers.
7. The semiconductor device of claim 1 , wherein the semiconductor device has a chip scale package.
8. The semiconductor device of claim 1 , wherein the semiconductor device has a wafer level chip scale package.
9. The semiconductor device of claim 1 , wherein the electronic circuitry includes source areas, drain areas, and gate electrodes.
10. The semiconductor device of claim 9 , further comprising a first electrode formed on the first surface, a second electrode formed on the second surface, and a conductive layer formed in the through hole to interconnect the first and second electrodes.
11. The semiconductor device of claim 1 , further comprising a first electrode formed on the first surface, a second electrode formed on the second surface, and a conductive layer formed in the through hole to interconnect the first and second electrodes.
12. A semiconductor device comprising:
a semiconductor substrate having a center of volume, a central axis passing through the center of volume, a first surface extending substantially orthogonal to the central axis, electronic circuitry formed on the first surface, a second surface extending substantially orthogonal to the central axis, an edge extending substantially parallel to the central axis from the first surface to the second surface, and a peripheral part inwardly adjacent to the edge,
wherein:
the peripheral part has a through hole extending from the first surface to the second surface, the through hole being separated from the central axis by a distance that diminishes as the through hole approaches the second surface;
the through hole originates in a first opening on the first surface and terminates in a second opening on the second surface, and has an inner wall extending from the first opening to the second opening;
a first geometric projection, formed by projecting the first opening onto the second surface parallel to the central axis, overlaps at least part of the second opening;
a first dielectric layer extending continuously from the first surface to the second surface on at least part of the inner wall of the through hole, passing through at least part of a second geometric projection formed by projecting the first opening parallel to the central axis onto the inner wall; and
a conductive layer formed on the first dielectric layer, extending continuously from the first surface to the second surface, passing through at least part of the second geometric projection.
13. The semiconductor device of claim 12 , wherein the first dielectric layer is a sprayed layer of dielectric material.
14. The semiconductor device of claim 12 , wherein the conductive layer is a sprayed layer of conductive material.
15. The semiconductor device of claim 12 , further comprising:
a second dielectric layer formed on the first dielectric layer and the conductive layer, the second dielectric layer filling the through hole.
16. The semiconductor device of claim 12 , further comprising:
a first layer of redistribution wiring disposed on the upper surface of the semiconductor substrate, electrically connected to the conductive layer; and
a second layer of redistribution wiring disposed on the lower surface of the semiconductor substrate, electrically connected to the conductive layer.
17. The semiconductor device of claim 16 , wherein the conductive layer includes an electrode disposed on the first surface of the semiconductor substrate, the electrode leading away from the through hole, the first layer of redistribution wiring being electrically connected to the electrode, the first layer of redistribution wiring being routed to avoid the through hole.