Computer-aided design and analysis of circuits and semiconductor – Nanotechnology related integrated circuit design
Reexamination Certificate
2002-09-16
2004-02-03
Smith, Matthew (Department: 2825)
Computer-aided design and analysis of circuits and semiconductor
Nanotechnology related integrated circuit design
C716S030000, C716S030000, C716S030000
Reexamination Certificate
active
06687880
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to integrated circuits. More, particularly, this invention relates to reducing spacing between a bus and adjacent circuits. Still more particularly, this invention relates to defining slots in the bus during design of an integrated circuit to reduce the space needed between the bus and adjacent circuitry.
2. The Prior Art
As the electrical arts advance, the amount of circuitry in an integrated circuit is increasing. Therefore, it is a problem for those that design integrated circuits to maximize the space in an integrated circuit where circuitry can be placed.
Currently, designers of integrated circuits are limited by the spacing requirements between a bus and circuits that are adjacent to the bus in the integrated circuit. For purposes of this discussion, a bus is a strip or line of conductive material which carries signals between circuits and a circuit is any configuration of circuitry that is in the integrated circuit. Also, for purposes of this discussion, conductive material is a metal or other type of substance having properties that allow transmission of electric signals.
The present design process requires a designer to place a solid strip of conductive material in a layer of the integrated circuit. The designer must then use the properties of the solid strip of conductive material to determine the spacing between the strip and a circuit that is adjacent to the strip. The designer then places the circuit adjacent to the bus with the determined amount of spacing separating the circuit from the bus.
FIG. 1
illustrates the above-described configuration. In layer
100
of an integrated circuit, a bus
101
is a solid strip of conductive material. Circuit
102
and circuit
103
are adjacent to bus
101
on opposite sides of bus
101
. Circuit
102
and circuit
103
are both separated by distance D, represented by arrows
104
and
105
, from bus
101
. Distance D is determined from the width of bus
101
. The width of bus
101
is used to determine the density of the conductive material in bus
101
which dictates the distance D of separation that must be maintained by the bus and an adjacent circuit.
After the circuit is designed with the bus made of a solid strip of conductive material. The design is provided to the manufacturer. The manufacturer then cuts slots into the strip of conductive material of the bus. The slots remove conductive material to change the density of conductive material in the bus and make the bus more manufacturable.
FIG. 2
illustrates a layer
200
of integrated circuit after the routing is completed in the manufacturing process. In layer
200
, bus
100
is a strip of conductive material that has slots
201
in the strip. Each slot
201
is devoid of conductive material. The slots change the amount of conductive material in the strip, which in turn changes the density of the material. However, the distance, D, between the bus and adjacent circuits
102
,
103
has not been changed. Therefore, circuits
102
and
103
are further away from the bus than is needed.
BRIEF DESCRIPTION OF THE INVENTION
This patent discloses and claims a useful, novel, and unobvious invention for an integrated circuit with reduced separation between a bus and adjacent circuits. In accordance this invention, slots are put into a strip of conductive material of a bus to reduce the amount of conductive material in the bus. The addition of the slots is performed during the design of the integrated circuit as opposed to during a post design step.
The addition of the slots into the strip of conductive material of the bus during the design process offers many advantages. A first advantage is that since the final density of conductive material in the bus is known at design time, the spacing between the bus and adjacent circuits maybe reduced. A second advantage is that since the position of the slots is known to the designer at design time, a designer may avoid placing connectors to other circuits over slots causing a disconnect.
In accordance with the present invention a layer of an integrated circuit has a first circuit in the layer and a bus in the layer. The bus is adjacent to the first circuit. The bus is a strip of conductive material with at least one slot defined in the strip. The slot removes conductive material from the strip to allow a reduction of spacing between the bus and the first circuit. The other configurations of this integrated circuit are described below.
In order to provide the integrated circuit described above, an integrated circuit is designed in the following manner. First, a strip of conductive material acting as a bus is placed in a first layer of the integrated circuit. Slots are then defined in the conductive material of the strip to remove conductive material in the strip. The spacing between the bus and an adjacent circuit is then determined from the amount of conductive material in the strip after the slots have been made. A circuit is then placed adjacent to the bus with the amount of separation determined by the amount of conductive material in the strip.
REFERENCES:
patent: 4187391 (1980-02-01), Voser
patent: 5200807 (1993-04-01), Eguchi
patent: 5812384 (1998-09-01), Ramakrishnan et al.
Rivera Billie Jean
Walker William Gordon
Lin Sun James
Sierra Patent Group Ltd.
Smith Matthew
Virtual Silicon Technology, Inc.
LandOfFree
Integrated circuit having a reduced spacing between a bus... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Integrated circuit having a reduced spacing between a bus..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Integrated circuit having a reduced spacing between a bus... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3307754