Semiconductor device and method of forming conductive protrusion over conductive pillars or bond pads as fixed offset vertical interconnect structure
View Patent ↗A semiconductor device has a semiconductor die mounted to a substrate. A plurality of conductive pillars is formed over a semiconductor die. A plurality of conductive protrusions is formed over the conductive pillars. Bumps are formed over the conductive protrusions and conductive pillars. Alternatively, the conductive protrusions are formed over the substrate. A conductive layer is formed over the substrate. The semiconductor die is mounted to the substrate by reflowing the bumps at a temperature that is less than a melting point of the conductive pillars and conductive protrusions to metallurgically and electrically connect the bumps to the conductive layer while maintaining a fixed offset between the semiconductor die and substrate. The fixed offset between the semiconductor die and substrate is determined by a height of the conductive pillars and a height of the conductive protrusions. A mold underfill material is deposited between the semiconductor die and substrate.
1. A method of making a semiconductor device, comprising:
providing a semiconductor die;
forming a plurality of conductive pillars over the semiconductor die;
forming a plurality of conductive protrusions over the conductive pillars by,
(a) forming a first patterning layer over the semiconductor die,
(b) forming a plurality of first vias in the first patterning layer,
(c) depositing conductive material in the first vias, and
(d) removing the first patterning layer, wherein a height of the conductive pillars is greater than or equal to a height of the conductive protrusions;
forming a plurality of bumps over the conductive protrusions and conductive pillars;
providing a substrate;
disposing the semiconductor die over the substrate; and
reflowing the bumps at a temperature that is less than a melting point of the conductive pillars and conductive protrusions with the conductive pillars and conductive protrusions maintaining a fixed offset between the semiconductor die and substrate.
2. The method of claim 1 , further including forming the conductive protrusions over a centerline of the conductive pillars.
3. The method of claim 1 , wherein forming the plurality of conductive pillars includes:
forming a second patterning layer over the semiconductor die;
forming a plurality of second vias in the second patterning layer;
depositing conductive material in the second vias; and
removing the second patterning layer.
4. The method of claim 1 , further including depositing a mold underfill material between the semiconductor die and substrate.
5. A method of making a semiconductor device, comprising:
providing a first substrate;
forming a first patterning layer over the first substrate;
forming a first via in the first patterning layer;
depositing conductive material in the first via to form a conductive pillar;
forming a conductive protrusion extending from a surface of the conductive pillar by,
(a) forming a second patterning layer over the conductive pillar,
(b) forming a second via in the second patterning layer,
(c) depositing conductive material in the second via, and
(d) removing the second patterning layer;
removing the first patterning layer; and
forming a bump over the conductive protrusion.
6. The method of claim 5 , further including:
disposing the first substrate over a second substrate; and
reflowing the bump at a temperature that is less than a melting point of the conductive protrusion while maintaining a fixed offset between the first substrate and second substrate.
7. The method of claim 6 , wherein the fixed offset between the first substrate and second substrate is determined by a height of the conductive pillar and a height of the conductive protrusion.
8. The method of claim 6 , further including depositing a mold underfill material between the first substrate and second substrate.
9. The method of claim 5 , wherein a height of the conductive pillar is greater than or equal to a height of the conductive protrusion.
10. The method of claim 5 , wherein the first substrate includes a semiconductor die.
11. A method of making a semiconductor device, comprising:
providing a semiconductor die;
forming a conductive pillar over the semiconductor die;
forming a conductive protrusion extending from a surface of the conductive pillar, wherein a width of the conductive protrusion at the surface of the conductive pillar is less than a width of the conductive pillar;
forming a bump over the conductive protrusion and conductive pillar;
disposing the semiconductor die, conductive protrusion, and bump over a substrate; and
reflowing the bump at a temperature that is less than a melting point of the conductive protrusion while the conductive protrusion maintains a fixed offset extending from the surface of the conductive pillar to a surface of the substrate.
12. The method of claim 11 , further including forming a conductive via through the substrate.
13. The method of claim 11 , wherein a height of the conductive pillar is greater than or equal to a height of the conductive protrusion.
14. The method of claim 11 , wherein forming the conductive protrusion includes:
forming a patterning layer over the conductive pillar;
forming a via in the patterning layer;
depositing conductive material in the via; and
removing the patterning layer.
15. The method of claim 11 , further including depositing a mold underfill material between the semiconductor and substrate.