Method for routing circuit boards

• US 4,642,890 A
• Filed: 10/31/1985
• Issued: 02/17/1987
• Est. Priority Date: 10/31/1985
• Status: Expired due to Term

• Current Assignee: AT&T Teleholdings Incorporated (AT&T, Inc.)
• Original Assignee: AT&T Teleholdings Incorporated (AT&T, Inc.)
• Inventors: Levine, Zachary H., Hechtman, Charles D.
• Primary Examiner(s): Rosenbaum, Mark
• Assistant Examiner(s): Arbes, Carl J.
• Application Number:
  US06/793,618
• Time in Patent Office: 474 Days
• Field of Search: 29/846, 364/488, 364/489, 364/491
• US Class Current: 29/846
• CPC Class Codes: H05K 2203/056 Using an artwork, i.e. a photomask for exposing photosensitive layers
• CPC Class Codes: H05K 2203/105 Using an electrical field; Special methods of applying an electric potential electroplating H05K2203/0723
• CPC Class Codes: H05K 3/0002 for manufacturing artworks for printed circuits
• CPC Class Codes: H05K 3/0005 for designing circuits by computer
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

The routing of non-crossing conductive paths (24--24) between each of two families of conductive nodes (18--18) and (20--20) on a surface (15) of a substrate (14) can be facilitated using electrostatic analog. To route the conductive paths (24--24), a two dimensional electrostatic force field is mathematically simulated on the surface (15) by attributing an equal charge to each of the nodes (18--18) of one family opposite that attributed to the nodes (20--20) of the other family, such that the total sum of the charges is zero. Lines of electric flux within the simulated force field are located and a set of flux lines, which link one of the nodes in one family to a separate node in the other family, is then selected. The flux lines in the set are non-crossing because of the properties of the simulated electric field and further a 1:1 matching between nodes (18--18 and 20--20) by the selected set of flux lines is guaranteed. Therefore the pattern of flux lines in the set can be employed to establish a pattern for the paths (24--24).

Claims

1. A method for routing conductive paths between each of two families of nodes of a body comprising the steps of:

simulating an electrostatic force field between the two families of nodes by attributing an equal charge to each of the nodes of one family whicn is opposite in polarity to the point charge attributed to each of the nodes of the other family such that the total sum of the charges is zero;

locating lines of electric flux within the simulated electrostatic force field;

selecting, from the lines of electric flux, a subset of lines which each terminate at a separate one of the nodes in each family; and

routing the conductive paths between the nodes of the two families such that each path coincides with a separate one of the selected subset of flux lines.

2. The method according to claim 1, wherein the selecting step comprises:

(a) grouping each of the flux lines which terminate at the same pair of nodes into separate sets;

(b) designating the shortest flux line within each and discarding the other lines in the set;

(c) eliminating the longest of the flux lines which remain and then finding a subset of flux lines which link the nodes in one family to a separate one of the nodes in the other family; and

(d) repeating step (c) until a subset of flux lines cannot be found which link with nodes in one family to the separate one of the nodes in the other family.

3. The method according to claim 1 further including the steps of:

(a) displaying the pattern of the selected subset of flux lines; and

(b) editing the pattern of the selected subset of flux lines to enhance the pattern of the conductive paths represented thereby.

4. A method for routing conductive paths on a substrate between each of two families of nodes thereon comprising the steps of:

simulating a two-dimensional electrostatic force field on the surface of the substrate by attributing an equal charge to each of the nodes of one family which is opposite to that attributed to each of the nodes of the other family such that the total sum of the charges is zero;

locating lines of electric flux within the force field;

designating the shortest flux line within each set of lines which terminate the same pair of nodes;

eliminating all the remaining lines within each set otherwise not designated;

successively eliminating the longest of the designated flux lines and then matching the flux lines that remain to obtain a subset of lines which link the nodes in the two families, the step of successively eliminating the longest of the designated flux lines and the matching of the lines that remain being repeated until one of the nodes in each family is no longer linked to a separate one of the nodes in the other family by a flux line; and

routing conductive paths between the nodes of the two families so that each path coincides with the location of a separate one of the flux lines which each link a separate one of the nodes in the two families.

5. A method for plotting images on an art master which correspond to a pattern of routes linking each of a plurality of nodes in one family to a separate one of a plurality of nodes in another family comprising the steps of:

simulating an electrostatic force field between nodes of each of the two families by attributing a charge to each of the nodes in one family opposite to that attributed to the nodes of the other, such that the total sum of the charges is zero;

locating lines of electric flux within the simulated electrostatic force field;

selecting a set of lines of electric flux within the field which each terminates at a separate pair of nodes each in separate families; and

plotting the pattern of the selected set of flux lines, together with the pattern of nodes on the art master.

6. The method according to claim 5, wherein the selecting step comprises:

(a) grouping each of the flux lines which terminate at the same pair of nodes into a separate set;

(b) designating the shortest flux line within each and discarding the other lines in the set;

(c) eliminating the longest of the flux lines which remain and then finding a subset of flux lines which link the nodes in one family to a separate one of the nodes in the other family; and

(d) repeating step (c) until a subset of flux lines cannot be found which link with nodes in one family to the separate one of the nodes in the other family.