Multi-use substrate for integrated circuit
View Patent ↗A sub-assembly for a packaged integrated circuit (IC) device has a planar substrate. The substrate's top side has multiple sets electrically connected bond posts arranged in corresponding nested contour zones. Each contour zone includes a different bond post of each bond-post set. The bottom side has a different set of pad connectors electrically connected to the each top-side bond-post set. The sub-assembly can be used for different IC packages having IC dies of different sizes, with different contours of bond posts available for electrical connection depending on the size of the IC die.
1. A sub-assembly for a packaged integrated circuit (IC) device, the sub-assembly comprising a planar substrate, the substrate having a top side and a bottom side, wherein:
the top side comprises a plurality of bond-post sets of two or more bond posts arranged in two or more nested contour zones;
the two or more nested contour zones include an outer contour zone and an inner contour zone located inside the outer contour zone;
the two or more bond posts of each bond-post set of the plurality of bond-post sets are directly conductively connected to each other;
each bond-post set of the plurality of bond-post sets comprises an outer bond post located within the outer contour zone and an inner bond post located within the inner contour zone; and
the bottom side comprises a plurality of pad connectors, wherein each pad connector is conductively connected to a corresponding bond-post set of the plurality of bond-post sets.
2. The sub-assembly of claim 1 , wherein the top side is covered with a solder mask layer having openings for the bond posts of the plurality of bond-post sets.
3. The sub-assembly of claim 2 , wherein the bottom side is covered with a solder mask layer having openings for the pad connectors of the plurality of pad connectors.
4. The sub-assembly of claim 1 , further comprising an IC die (i) mounted on the top side and (ii) wire bonded only to bond posts located in one contour zone.
5. The sub-assembly of claim 4 , wherein the sub-assembly further comprises a molding compound encapsulating the IC die and bond wires.
6. The sub-assembly of claim 4 , wherein:
the sub-assembly is a land grid array (LGA) IC device; and
the pad connectors of the plurality of pad connectors are pad openings.
7. The sub-assembly of claim 4 , wherein:
the sub-assembly is a ball grid array (BGA) IC device; and
the pad connectors of the plurality of pad connectors are solder ball pad openings.
8. The sub-assembly of claim 4 , wherein:
the sub-assembly is a pin grid array (PGA) IC device; and
the pad connectors of the plurality of pad connectors are pins.
9. The sub-assembly of claim 1 , further comprising an IC die, wherein:
the die is mounted on the top side using a die-attach material;
the die-attach material covers up at least a portion of the bond posts located within the inner contour zone;
the die-attach material does not cover up the bond posts located within the outer contour zone; and
the die is wire bonded to bond posts located only in the outer contour zone.
10. The sub-assembly of claim 1 , further comprising an IC die flip-mounted on the top side and ball bonded to bond posts located only in one of the inner and outer contour zones.
11. The sub-assembly of claim 1 , wherein the contour zones are nested rectangular rings.
12. The sub-assembly of claim 11 , wherein the contour zones are concentric.
13. The sub-assembly of claim 1 , wherein:
the top side further comprises a first intermediate contour zone, different from the inner and outer contour zones and located between the inner and outer contour zones;
each bond-post set of the plurality of bond-post sets further comprises a first intermediate bond post located within the first intermediate contour zone.
14. The sub-assembly of claim 13 , wherein:
the sub-assembly is adapted for mounting by a first-size IC die using the bond posts of only the inner contour zone for wire bonding the first-size IC die;
the sub-assembly is adapted for mounting by a second-size IC die, larger than the first-size IC die, using the bond posts of only the intermediate contour zone for wire bonding the second-size IC die; and
the sub-assembly is adapted for mounting by a third-size IC die, larger than the second size IC die, using the bond posts of only the outer contour zone for wire bonding the third-size IC die.
15. The sub-assembly of claim 1 , wherein:
the sub-assembly has a die paddle region in the center of the top side for the mounting of a die;
the die paddle region comprises a first thermo-conductive pad; and
the bottom side comprises a second thermo-conductive pad thermo-conductively connected to the first thermo-conductive pad via the substrate.
16. The sub-assembly of claim 15 , wherein the thermo-conductive pads and the bond posts comprise copper.
17. The sub-assembly of claim 15 , wherein:
the die paddle region comprises a first plurality of thermo-conductive pads that includes the first thermally conductive pad;
the bottom side comprises a second plurality of thermo-conductive pads that includes the second thermo-conductive pad; and
each pad of the first plurality of thermo-conductive pads is thermo-conductively connected to a corresponding pad of the second plurality of thermo-conductive pads via the substrate.
18. A method for manufacturing a sub-assembly for a packaged integrated circuit (IC) device, the method comprising manufacturing a planar substrate having a top side and a bottom side, wherein:
the top side comprises a plurality of bond-post sets of two or more bond posts arranged in two or more nested contour zones;
the two or more nested contour zones include an outer contour zone and an inner contour zone located inside the outer contour zone;
the two or more bond posts of each bond-post set of the plurality of bond-post sets are directly conductively connected to each other;
each bond-post set of the plurality of bond-post sets comprises an outer bond post located within the outer contour zone and an inner bond post located within the inner contour zone; and
the bottom side comprises a plurality of pad connectors, wherein each pad connector is conductively connected to a corresponding bond-post set of the plurality of bond-post sets.