Semiconductor package and method using isolated V
View Patent ↗Embodiments of the invention include a semiconductor integrated circuit package that includes a substrate which can have an integrated circuit die attached thereto. The package includes a dedicated high-speed ground plane that is electrically isolated from the ground plane used to ground the low speed circuitry of the package.
1. A semiconductor integrated circuit (IC) package which comprises:
a substrate having a first surface and a second surface wherein;
a first layer of the substrate includes,
a first ground plane enabling electrical connection with low speed electronic circuitry, and
a second ground plane that is spatially separated and electrically isolated from the first ground plane, the second ground plane enabling electrical connection with high speed electronic circuitry;
a second layer of the substrate includes,
a third ground plane configured for electrical connection with low speed electronic circuitry, and
a fourth ground plane that is spatially separated and electrically isolated from the third ground plane, the third ground plane configured for electrical connection with high speed electronic circuitry;
a plurality of electrical connections that electrically connect the first ground plane with solder balls mounted on the second surface of the substrate;
a plurality of additional electrical connections that electrically connect the second ground plane with solder balls mounted on the second surface of the substrate; and
peripheral electrical contacts arranged on the substrate and configured for connection with electronic circuitry external to the package; and
at least one reference plane associated with each layer of the substrate and the ground planes included thereon.
2. An IC package as recited in claim 1 wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the second set of electrical contacts are spaced apart at a distance that is at least twice as far apart as the spacing for the first set of electrical contacts.
3. An IC package as recited in claim 2 wherein the first set of electrical contacts are spaced apart a distance of at least 70 μm (micrometers) and wherein the second set of electrical are spaced apart a distance of at least 140 μm (micrometers).
4. An IC package as recited in claim 2 wherein the first set of electrical contacts are spaced apart a distance of at least 70 μm (micrometers) and wherein the second set of electrical are spaced apart a distance of at least 200 μm (micrometers).
5. An IC package as recited in claim 1 wherein the low speed electronic circuitry is defined as circuitry having serial transfer rates of less than about 1 Gigabits per second (Gb/s); and
wherein the high speed electronic circuitry is defined as circuitry having serial transfer rates of greater than about 1 Gb/s.
6. An IC package as recited in claim 1 wherein the high speed electronic circuitry is defined as circuitry having serial transfer rates of greater than about 8.5 Gb/s.
7. An IC package as recited in claim 1 wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the second set of electrical contacts are spaced apart at a distance that is at least three times as far apart as the spacing for the first set of electrical contacts.
8. An IC package as recited in claim 1 wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the second set of electrical contacts are spaced apart at a distance sufficient to establish a differential impedance of at least 100 ohms (Ω) between the contacts of the second set.
9. An IC package as recited in claim 1 wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the electrical contacts are arranged such that,
the first spacing between the contacts of the first set of electrical contacts is smaller than a second spacing between the contacts of the second set of electrical contacts, thereby enabling greater contact density for the first set of electrical contacts.
10. An IC package as recited in claim 1 wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the electrical contacts are arranged as part of I/O lines such that,
a first spacing between the contacts of the first set of electrical contacts is sufficient to establish a control differential impedance of at least 50Ω between the contacts of the first set of electrical contacts to substantially eliminate cross-talk between I/O lines for the low speed electronic circuitry; and
a second spacing between the contacts of the second set of electrical contacts is sufficient to establish a control differential impedance of at least 100Ω between the contacts of the second set of electrical contacts to substantially eliminate cross-talk between I/O lines for the high speed electronic circuitry.
11. An IC package as recited in claim 1 wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the electrical contacts are arranged such that,
a first spacing between the contacts of the first set of electrical contacts is sufficient to establish a control differential impedance of at least 50Ω between the contacts of the first set of electrical contacts; and
a second spacing between the contacts of the second set of electrical contacts is sufficient to establish a control differential impedance of at least 100Ω between the contacts of the second set of electrical contacts.
12. An IC package as recited in claim 1 wherein the first surface includes a die attachment surface with a die arrangement attached thereto,
the die arrangement being electrically connected to the first ground plane, the second ground plane, and the peripheral electrical contacts of the substrate.
13. An IC package as recited in claim 12 wherein the die arrangement comprises a die having both high-speed electronic circuitry and low-speed electronic circuitry; and
wherein the peripheral electrical contacts include,
a first set of electrical contacts for electrical connection with low speed electronic circuitry; and
a second set of electrical contacts for electrical connection with high speed electronic circuitry; and
wherein the low-speed electronic circuitry is connected with the first ground plane and is electrically connected with the first set of electrical contacts that are spaced for connection with the low speed electronic circuitry; and
wherein the high-speed electronic circuitry is connected with the second ground plane and is electrically connected with the second set of electrical contacts that are spaced for connection with the high speed electronic circuitry.
14. An IC package as recited in claim 13 wherein the die arrangement comprises a stacked die arrangement wherein at least one die has high-speed electronic circuitry and wherein at least one die has low-speed electronic circuitry;
wherein the low-speed electronic circuitry is connected with the first ground plane and is electrically connected with the first set of electrical contacts that are spaced for connection with the low speed electronic circuitry; and
wherein the high-speed electronic circuitry is connected with the second ground plane and is electrically connected with the second set of electrical contacts that are spaced for connection with the high speed electronic circuitry.