Integrated circuit interconnect system

• US 20030006856A1
• Filed: 08/02/2002
• Published: 01/09/2003
• Est. Priority Date: 02/25/1999
• Status: Active Grant

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Miller, Charles A.
• Granted Patent: US 6,646,520 B2
• Time in Patent Office: Days
• US Class Current: 333/32
• CPC Class Codes: H01L 2223/6611 Wire connections
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/4813 Connecting within a semiconductor or solid-state body, i.e. fly wire, bridge wire
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 23/62 Protection against overvoltage, e.g. fuses, shunts
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 27/0248 for electrical or thermal protection, e.g. electrostatic discharge [ESD] protection
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01083 : Bismuth [Bi]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19042 : being an inductor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/30111 : matching

Abstract

In an interconnect system for providing access to a common I/O terminal for multiple circuit devices such as drivers, receivers and electrostatic discharge (ESD) protection devices implemented on an IC, each such device is provided with a separate contact pad within the IC. The contact pads are linked to one another and to the IC I/O terminal though inductive conductors such as bond wires, metalization layer traces in the IC, or legs of a forked, lithographically-defined spring contact formed on the IC. The conductor inductance isolates the capacitance of the circuit devices from one another, thereby improving characteristics of the frequency response of the interconnect system. Also the ESD protection function is distributed among multiple ESD devices interconnected by series inductors to provide a multi-pole filter at each IC terminal. The inductances of the conductors and various capacitances of the interconnect system are also appropriately adjusted to optimize desired interconnect system frequency response characteristics.

Claims

1. An interconnect system for conveying signals between a first circuit device implemented within an integrated circuit and a second circuit device external to said integrated circuit, the interconnect system comprising:

a first node within said integrated circuit, said first circuit device being connected to said first node;

a first electrostatic discharge protection device coupled to said first node,

a second node implemented within said integrated circuit,

a second electrostatic discharge protection device coupled to said second node,

an inductor connected between said first node and said second node, and

conductive means linking said second node to said second circuit device.

2. The interconnect system in accordance with claim 1

wherein said first and second nodes are bond pads implemented on said integrated circuit, and

wherein said inductor comprises a bond wire.

3. The interconnect system in accordance with claim 1

wherein said inductor comprises a spiral inductor implemented within said integrated circuit.

4. The interconnect system in accordance with claim 1

wherein said conductive means is inductive,

wherein said first and second electrostatic discharge protective devices are capacitive, and

wherein inductances of said inductor and said conductive means, and capacitances of said first and second electrostatic discharge protection devices are sized to substantially optimize a frequency response characteristic of said interconnect system.

5. The interconnect system in accordance with claim 4 wherein inductances of said inductor and said conductive means, and capacitances of said first and second electrostatic discharge protection devices are sized such that said interconnect system has a frequency response substantially similar to a frequency response of one of a Butterworth filter and a Chebyshev filter.

6. An interconnect system for conveying signals between a first circuit device implemented within an integrated circuit and a second circuit device external to said integrated circuit, the interconnect system comprising:

a first node within said integrated circuit, said first circuit device being connected to said first node;

a second node within said integrated circuit;

a third node within said integrated circuit;

a first electrostatic discharge protection device coupled to said second node;

a second electrostatic discharge protection device coupled to said third node;

a first inductor connected between said first node and said second node;

a third inductor connected between said first node and said second node; and

conductive means linking said second node to said third circuit device.

7. The interconnect system in accordance with claim 6

wherein said first, second and third nodes are bond pads implemented on said integrated circuit, and

wherein said first and second inductors comprise bond wires.

8. The interconnect system in accordance with claim 6

wherein at least one of said first and second inductors comprises a spiral inductor implemented within said integrated circuit.

9. The interconnect system in accordance with claim 6

wherein said conductive means is inductive,

wherein said first and second electrostatic discharge protective devices are capacitive, and

wherein inductances of said first and second inductors and said conductive means, and capacitances of said first and second electrostatic discharge protection devices are sized to substantially optimize a frequency response characteristic of said interconnect system.

10. The interconnect system in accordance with claim 9 wherein inductances of said first and second inductors and said conductive means, and capacitances of said first and second electrostatic discharge protection devices are sized such that said interconnect system has a frequency response substantially similar to a frequency response of one of a Butterworth filter and a Chebyshev filter.

11. An interconnect system for conveying signals between a driver and a receiver implemented within an integrated circuit and a circuit device external to said integrated circuit, the interconnect system comprising:

a node within said integrated circuit,

a first electrostatic discharge protection device;

a second electrostatic discharge protection device;

a first inductor connected between said node and said first electrostatic discharge protection device;

a second inductor connected between said node and said second electrostatic discharge protection device,

a third inductor connected between said first electrostatic discharge protection device and said driver;

a fourth inductor connected between said second electrostatic discharge protection device and said receiver; and

conductive means linking said node to said third circuit device.

12. The interconnect system in accordance with claim 11

wherein said conductive means is inductive,

wherein said first and second electrostatic discharge protective devices are capacitive, and

wherein inductances of said first, second, third and fourth inductors and said conductive means, and capacitances of said first and second electrostatic discharge protection devices are sized to substantially optimize a frequency response characteristic of said interconnect system.

13. The interconnect system in accordance with claim 12 wherein said interconnect system has a frequency response substantially similar to a frequency response of one of a Butterworth filter and a Chebyshev filter.

15. The interconnect system in accordance with claim 14 wherein said multi-pole filter has a frequency response substantially similar to a frequency response of one of a Butterworth filter and a Chebyshev filter.

16. The interconnect system in accordance with claim 14 wherein said plurality of inductors are connected in series between said circuit node and said first circuit device and wherein said plurality of electrostatic discharge protection devices provide shunt capacitance relative to signals passing through said inductors.

14. An interconnect system for conveying signals between a first circuit device implemented within an integrated circuit and a second circuit device external to said integrated circuit, the interconnect system comprising:

a circuit node implemented within said integrated circuit;

means for conductively linking said circuit node to said second circuit device; and

a multi-pole filter linking said first circuit device to said circuit node, said multiple-pole filter comprising a plurality of capacitive electrostatic discharge protection devices implemented within said integrated circuit and a plurality of inductors interconnecting said plurality of capacitive electrostatic discharge protection devices.