JPH0652532B2 - Circuit board wiring route search method by CAD - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a method for searching a wiring path of a circuit board by CAD. When searching a wiring path for a circuit board by CAD, the processing time is greatly shortened and the necessary processing is performed. For the purpose of significantly reducing the amount of data, a plurality of wiring traveling axes that run in the main wiring direction are arranged in parallel on the circuit board, and each wiring traveling axis is divided into an empty line that can be wired and an obstacle line that cannot be wired. , The empty line including the start point is searched sequentially until the empty line including the end point is reached until the empty line including the end point is reached. When it reaches, it determines the empty line from the end point to the starting point by tracing back the serial number, and at least one point in the overlapping section of the adjacent empty line between the two points is determined between the two. The wiring path is determined by determining the connection point of.

[Industrial application field]

The present invention relates to a wiring path searching method for a circuit board by CAD (Computer Aided Design).

In the wiring path search processing by CAD, it is necessary to speed up the processing and shorten the processing time.

[Conventional technology]

2. Description of the Related Art Conventionally, a cell system is used as a wiring process on a printed circuit board by a CAD device, that is, a process for searching a wiring path connecting one component pin position and the other component pin position.

In the cell method, the printed circuit board surface is divided into meshes in the X and Y axis directions, and information indicating the presence or absence of obstacles is held in each cell (called a cell) of this mesh, and cells without obstacles are held. The wiring pattern is searched by tracing from the start point to the end point.

That is, FIG. 3 is a diagram showing an example of the path search processing by the cell structure, in which each mesh-shaped cell in the figure is a cell, the shaded cells are obstacle cells, and the other cells are empty cells. is there. Further, S is a starting point cell corresponding to the starting point of the component pin, and E is an ending point cell corresponding to the ending point of the component pin.

The search for the pattern path from the start point cell S to the end point cell E is performed by (1) looking at the cells above and below and to the left and right of the start point cell S to determine whether or not they are obstacle cells. Since the pattern can be run, the additional number "1" is added to these cells as cell information.

(2) Next, looking at the upper, lower, left, and right cells from the cell with the serial number "1", and if those cells are not obstacle cells or cells to which the serial number has already been added, add "serial number +1" to those cells. Cell information is added. Note that the additional number addition process is not performed on cells to which the additional number has already been added as cell information.
When such a process is repeated, additional numbers 1, 2, 3, 4 ... Are sequentially added to adjacent empty cells as cell information starting from the starting point cell S.

(3) When the cell adjacent to the cell to which the additional number is added becomes the end point cell E, the route search processing is completed. In FIG. 3, the adjacent cell with the additional number “11” is the end point cell E.

The wiring pattern path is from the end cell E to the serial number of each cell,
It is obtained by tracing in the reverse order of E → 11 → 10 → 9 → ... → 3 → 2 → 1 → S and reaching the start point cell S.

[Problems to be Solved by the Invention]

In the search for the wiring path by the cell structure, when the start point cell S and the end point cell E are far apart, many cells must be routed therebetween. In this case, since cell information is stored for each of a large number of transit cells, the processing time becomes long and the amount of data to be processed becomes enormous.

Therefore, an object of the present invention is to significantly reduce the processing time and speed up the processing when searching the wiring path of the circuit board by CAD, and to significantly reduce the required processing data amount.

[Means for solving the problem]

According to a method of searching a wiring path of a circuit board by CAD according to the present invention, a plurality of wiring travel axes that run in the main wiring direction are arranged in parallel on the circuit board, and each wiring travel axis can be wired and an unobstructable obstacle line. The search is started from an empty line including the start point and the adjacent empty lines are sequentially searched until the empty line including the end point is reached, and the searched empty line is sequentially numbered, and the end point is included. When an empty line is reached, the trailing numbers are traced backward to determine an empty line from the end point to the starting point, and at least one point in the overlapped section of adjacent empty lines for this determined empty line is connected between them. The wiring route is determined by determining the location.

[Action]

The method of the present invention will be described with reference to the path search processing example of FIG. FIG. 1 is a diagram showing a path search process in an environment in which the positions of obstacles are the same as those in FIG.

In printed circuit board wiring, it is known that a method of determining a main wiring direction for each wiring layer with a substrate having a multi-layered structure and separately wiring in the XY axis directions contributes to improvement of a wiring rate.

In the method of the present invention, the path search is performed for each wiring layer, and FIG. 2 deals with the path search for the layer whose X-axis direction is the main wiring direction. That is, in FIG. 2, a plurality of pattern running axes L _{1 to} L ₈ parallel to the main wiring direction are arranged in rows. Each pattern running axis has an empty line structure divided into an empty line range in which the wiring pattern can travel and an impossible obstacle range. The obstacle range is indicated by a shaded area in the figure.

The path search from the starting point component pin position S to the ending point component pin position E is performed by the following procedure.

(1) An additional number “1” is added as blank line information to a blank line including the start point S on the area.

(2) Vertical wiring running axis L as seen from the empty line with the additional number “1”
₅ , an empty line position adjacent to the empty line “1” on L ₇ is searched, and if there is, an “additional number + 1” is added to the empty line as empty line information. At this time, if the additional number is already added to the empty line, the additional number addition process is not performed.

(3) The above process (2) is repeated until an additional number is added to the empty line including the end point E, and if the additional number is added to the empty line at the end point E, the path search process is completed. .

(4) From an empty line including the end point E, E → 4 → 3 → 2 → 1
→ Perform a reverse trace by tracing the serial numbers in reverse order in the order of S, and end point E
An empty line from the start point S to the start point S is determined.

(5) Regarding the empty line determined in (4) above, adjacent empty lines are connected according to a predetermined rule to determine a wiring pattern route. As a predetermined rule, the end point E on the empty line 4 and the starting point S on the empty line 1 are fixed points, and for example, between the empty line 4 and the empty line 3, the wirings of the two overlap each other. At least one point is the connection point between the two. This is also performed between the empty lines 3 and 2 and between the empty lines 2 and 1. At this time, as shown in FIG.
If wirings (a) and (b) that run in the plane area formed by these empty lines 1 to 4 in the direction perpendicular to the main wiring direction or in the direction of 45 ° and reach the empty lines 1 to 4 are possible, It is good to wire to.

In addition, as a result of the above connection, when an unnecessary part is generated because the electric paths overlap between the adjacent empty lines, it is preferable to release the part as an empty line again after the route is determined.

In the path search by this empty line structure, a place which has been conventionally composed of a plurality of pattern-runnable cells is made into a line and is regarded as one continuous line to be managed by FROM-TO coordinates. A connecting path generally requires fewer components. In the above example, the number of passing cells is 11 in the case of the conventional cell method, but the number of passing lines is only 4 in the empty line method of the present invention, and the difference in the number of passing components is the same as the path search. It is the difference in time and the amount of data reduction.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. Second
The drawing is a flow chart showing an embodiment of the procedure of printed circuit board wiring processing when the method of the present invention is applied to a CAD device for designing a printed circuit board for an exchange.

First, as an initial setting, based on data such as component pin positions and wiring prohibited areas, a pattern-runtable empty line and an obstacle line are determined for each running axis in the main wiring direction on the printed circuit board, and this information is used as an empty line. Memory D as structural information
It is held at 1 (step S2).

Next, from the entire wiring section, one piece of data of the starting point pin position and the ending point pin position of the wiring section to be subjected to wiring processing is extracted (step S3).

If there is no data to be extracted, it means that the wiring trial has been completed for all the wiring sections, so that the wiring process is completed (step S8).

If the unwired section has been extracted, a wiring path is searched for using the empty line structure described in the above section [Operation] for the section (step S4).

If the result of the route search indicates that wiring is not possible, the arrival serial number information added to each empty line in the wiring processing is cleared (step S7), and the unwired section is extracted again (step S).
3).

When a wirable path is found, the pattern data is added to the empty line structure D1 as obstacle data (step S6). After that, the serial number information of each empty line is cleared (step S7). The empty line structure D1 does not need to be reset every time wiring processing is performed in each section, and wiring result pattern data is added (updated) to the initial empty line structure as an obstacle.

When it is determined in step S3 that the wiring of all the sections is completed, the process is completed (step S8).

Similar to other printed circuit boards, printed circuit boards for exchanges are required to have a large-scale circuit and high stability of components mounted on the printed circuit board in order to satisfy many circuit functions.
This makes circuit wiring very complicated. The above-described method of the present invention has a large number of wiring sections, and has a remarkable effect of reducing the processing time and the processing data amount in the processing in which obstacles increase and wiring becomes complicated as the wiring progresses.

〔The invention's effect〕

According to the present invention, when the wiring path of the circuit board is searched by CAD, the processing time can be significantly shortened, the processing speed can be increased, and the required processing data amount can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a path search processing by the method of the present invention, FIG. 2 is a flow chart showing an example of a path search processing procedure in a CAD device to which the method of the present invention is applied, and FIG. 3 is a path by a conventional cell system. It is a figure explaining a search process. FIG. 4 is a diagram for explaining a wiring path in a direction perpendicular to the main wiring direction in the method of the present invention. In the figure, S ... Starting point, E ... Ending point 1-11 ... Serial number

Claims (1)

[Claims] 1. A plurality of wiring running axes that run in the main wiring direction are arranged in parallel on a circuit board, and each wiring running axis is divided into an empty line that can be wired and an obstacle line that cannot be wired, starting from an empty line that includes a starting point. Until the empty line including the end point is reached, the empty lines that are adjacent to each other are sequentially searched while adding the additional numbers to the searched empty lines. When the empty line including the end point is reached, the additional numbers are reversed. By determining an empty line from the end point to the starting point by tracing, and determining at least one point in the overlapping section of the adjacent empty line as the connection point between the two, the wiring route is determined. A method for searching a wiring path of a circuit board by CAD so as to determine.