Chip package with plank stack of semiconductor dies
In a chip package, semiconductor dies in a vertical stack of semiconductor dies or chips (which is referred to as a ‘plank stack’) are separated by a mechanical spacer (such as a filler material or an adhesive). Moreover, the chip package includes a substrate at a right angle to the plank stack, which is electrically coupled to the semiconductor dies along an edge of the plank stack. In particular, electrical pads proximate to a surface of the substrate (which are along a stacking direction of the plank stack) are electrically coupled to pads that are proximate to edges of the semiconductor dies by an intervening conductive material, such as: solder, stud bumps, plated traces, wire bonds, spring connectors, a conductive adhesive and/or an anisotropic conducting film. Note that the chip package may facilitate high-bandwidth communication of signals between the semiconductor dies and the substrate.
1. A chip package, comprising:
a group of semiconductor dies arranged in a plank stack in an x direction, wherein a plane of a given semiconductor die is defined by a z direction and a y direction, wherein a surface for the plane comprises active electronics, wherein the z direction, the x direction and the y direction are substantially perpendicular to each other, wherein the semiconductor dies include first electrical pads proximate to edges of the semiconductor dies, and wherein the edges of the semiconductor dies define a face of the plank stack;
a mechanical spacer between pairs of semiconductor dies in the group of semiconductor dies; and
a substrate electrically coupled to the semiconductor dies along the x direction, wherein a plane of the substrate is defined by the x direction and the y direction; and
wherein the electrical coupling to the semiconductor dies is between the first electrical pads, second electrical pads, proximate to a surface of the substrate along the x direction, and an intervening conductive material between the first electrical pads and the second electrical pads.
2. The chip package of claim 1 , wherein the semiconductor dies have a common orientation so that active electronics proximate to surfaces of the semiconductor dies are on a common side of the semiconductor dies.
3. The chip package of claim 1 , wherein pairs of adjacent semiconductor dies in the plank stack have opposite orientations so that active electronics proximate to surfaces of the pairs of adjacent semiconductor dies face each other.
4. The chip package of claim 1 , wherein the semiconductor dies include third electrical pads, proximate to the edges of the semiconductor dies along the y direction;
wherein the substrate is further electrically coupled to the semiconductor dies along the y direction; and
wherein the electrical coupling to the semiconductor dies is between the third electrical pads, fourth electrical pads, proximate to the surface of the substrate along the y direction, and the intervening conductive material between the third electrical pads and the fourth electrical pads.
5. The chip package of claim 1 , wherein the second electrical pads include one of: discrete pads and a continuous electrical signal line on the substrate.
6. The chip package of claim 1 , wherein the mechanical spacer includes spheres that define a spacing between the pairs of semiconductor dies.
7. The chip package of claim 1 , wherein the chip package further includes spacer bumps, mechanically coupled to surfaces of the pairs of semiconductor dies; and
wherein the spacer bumps define a spacing between the pairs of semiconductor dies.
8. The chip package of claim 1 , wherein the intervening conductive material includes one of: solder, partially ground conductive material having a modified aspect ratio than that of un-ground conductive material, stud bumps, plated traces, wire bonds, spring connectors that are electrically coupled to the substrate, traces defined using tape automated bonding, and a conductive adhesive.
9. The chip package of claim 1 , wherein the intervening conductive material extends beyond a guard ring associated with the given semiconductor die.
10. The chip package of claim 1 , wherein the mechanical spacer is recessed from the first electrical pads in spaces between the pairs of semiconductor dies.
11. The chip package of claim 1 , wherein the mechanical spacer fills the spaces between the pairs of semiconductor dies down to the first electrical pads.
12. The chip package of claim 1 , wherein the semiconductor dies include third electrical pads proximate to additional edges of the semiconductor dies;
wherein the additional edges of the semiconductor dies define another face of the plank stack;
wherein the chip package further includes another substrate that is electrically coupled to the semiconductor dies along one of the x direction or the y direction; and
wherein the electrical coupling to the semiconductor dies is between the third electrical pads, fourth electrical pads, proximate to the surface of the substrate along the z direction, and the intervening conductive material between the third electrical pads and the fourth electrical pads.
13. The chip package of claim 1 , wherein the chip package includes a heat sink thermally coupled to at least another face of the plank stack than the face of the plank stack, thereby extracting heat from one or more faces of the plank stack.
14. The chip package of claim 1 , wherein the group of semiconductor dies includes at least two subsets of semiconductor dies that are separated by a gap along the x direction; and
wherein a given subset of the semiconductor dies includes at least two semiconductor dies.
15. The chip package of claim 1 , wherein the mechanical spacer includes an adhesive.
16. A system, comprising a chip package, wherein the chip package includes:
a group of semiconductor dies arranged in a plank stack in an x direction, wherein a plane of a given semiconductor die is defined by a z direction and a y direction, wherein a surface for the plane comprises active electronics, wherein the z direction, the x direction and the y direction are substantially perpendicular to each other, wherein the semiconductor dies include first electrical pads proximate to edges of the semiconductor dies; and wherein the edges of the semiconductor dies define a face of the plank stack;
a mechanical spacer between pairs of semiconductor dies in the group of semiconductor dies; and
a substrate electrically coupled to the semiconductor dies along the x direction, wherein a plane of the substrate is defined by the x direction and the y direction; and
wherein the electrical coupling to the semiconductor dies is between the first electrical pads, second electrical pads, proximate to a surface of the substrate along the x direction, and an intervening conductive material between the first electrical pads and the second electrical pads.
17. The chip package of claim 1 , wherein the surface for the plane is defined by the z direction and the y direction and is substantially parallel to the plane.
18. The chip package of claim 1 , wherein the plane for the given semiconductor die is substantially parallel to a plane of another semiconductor die in the group that is defined by the z direction and the y direction.
19. The chip package of claim 1 , wherein, for each semiconductor die in the semiconductor dies:
a plane for the semiconductor die is defined by the z direction and the y direction,
the plane for the semiconductor die is substantially parallel to each of the planes for the semiconductor dies, and
a surface for the plane for the semiconductor die that is substantially parallel to the plane comprises active electronics for the semiconductor die.
20. The chip package of claim 17 , wherein, for each semiconductor die in the semiconductor dies, the first electrical pads for the semiconductor die are disposed on the surface for the plane for the semiconductor die.