Exposed die overmolded flip chip package and fabrication method
View Patent ↗An exposed die overmolded flip chip package includes a substrate. A die is flip chip mounted to an upper surface of the substrate. The package further includes a mold cap filling a space between an active surface of the die and the upper surface of the substrate. The mold cap includes a principal surface, sidewalls extending from the upper surface of the substrate to the principal surface, an annular surface coplanar with the inactive surface of the die and extending outward from a peripheral edge of the inactive surface of the die, and protruding surfaces extending between the principal surface and the annular surface. The mold cap does not cover the inactive surface of the die such that heat transfer from the die to the ambient environment is maximized and the package thickness is minimized.
1. An exposed die overmolded flip chip package comprising:
a substrate comprising a first surface;
a die flip chip mounted to the first surface of the substrate, the die comprising an inactive surface;
a mold cap comprising a channel directly adjacent the inactive surface, the inactive surface being exposed from the mold cap; and
electrically conductive vias within the mold cap.
2. The exposed die overmolded flip chip package of claim 1 wherein the vias extend from the substrate to a principal surface of the mold cap.
3. The exposed die overmolded flip chip package of claim 1 further comprising interconnection balls on the vias.
4. The exposed die overmolded flip chip package of claim 1 further comprising openings within the mold cap, the vias comprising electrically conductive material within the openings.
5. The exposed die overmolded flip chip package of claim 4 wherein the openings are formed using laser ablation.
6. The exposed die overmolded flip chip package of claim 1 wherein the mold cap fills a space between an active surface of the die and the first surface of the substrate.
7. The exposed die overmolded flip chip package of claim 1 wherein a height of the inactive surface of the die from the first surface of the substrate is greater than a height of the entire mold cap from the first surface of the substrate.
8. The exposed die overmolded flip chip package of claim 1 wherein the entire inactive surface of the die is exposed directly to the ambient environment from the mold cap in the final assembly of the exposed die overmolded flip chip package.
9. An exposed die overmolded flip chip package comprising:
a substrate comprising a first surface;
a die comprising:
an active surface;
an inactive surface opposite the active surface; and
sides extending between the active surface and the inactive surface;
a mold cap comprising a channel in a principal surface of the mold cap, wherein a portion of the sides of the die are exposed from the mold cap; and
electrically conductive vias within the mold cap.
10. The exposed die overmolded flip chip package of claim 9 further comprising:
flip chip bumps coupling the die to the first surface of the substrate.
11. The exposed die overmolded flip chip package of claim 10 wherein the mold cap encloses the flip chip bumps.
12. The exposed die overmolded flip chip package of claim 11 wherein the mold cap fills a space between the active surface of the die and the first surface of the substrate.
13. The exposed die overmolded flip chip package of claim 9 further comprising traces coupled to the first surface of the substrate, the vias being coupled to the traces.
14. The exposed die overmolded flip chip package of claim 9 further comprising:
interconnection balls on the vias.
15. The exposed die overmolded flip chip package of claim 14 wherein the interconnection balls are formed on the vias at the principal surface.
16. A method comprising:
mounting a die to a substrate with flip chip bumps;
forming a mold cap comprising a channel in a principal surface of the mold cap, wherein an inactive surface and a portion of sides of the die are exposed from the mold cap;
forming electrically conductive vias extending from the substrate.
17. The method of claim 16 wherein the forming electrically conductive vias is performed subsequent to the forming a mold cap.
18. The method of claim 16 where the forming electrically conductive vias comprises:
forming openings in the mold cap; and
providing electrically conductive material in the openings.
19. The method of claim 16 wherein the vias extend from the substrate to the principal surface of the mold cap.
20. The method of claim 16 further comprising:
forming interconnection balls on the vias at the principal surface.