JPH07175846A - Interactive wiring design method - Google Patents

Abstract

PURPOSE:To reduce design man-hours by judging whether or not the wiring of a line width and clearance read out from a priority library in order of priority can pass through between obstructions. CONSTITUTION:A designer makes a line width library 22, a clearance library 23, and a priority library 21 store respective information. CAD calculates distance between the obstructions in a through hole land, etc., where the short- circuit in wiring including the line width and clearance to be decided is absolutely inhibited, and applies first line width and clearance in the priority library 21. Thence, when it is possible to pass through the wiring of line width/clearance designated within the distance between the obstructions, the line width and clearance of the wiring are decided, and the display color and display line kind of a decided wiring are displayed. Therefore, the designer can recognize the decided line width and the clearance by the display color and display line kind of the wiring. Also, when the wiring is disabled, the next ID of the priority library 21 is retrieved, and the feasibility/infeasibility of the wiring can be judged by applying the next line width and clearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interactive wiring design method, and more particularly to a method for interactively determining the wiring width and clearance of a printed circuit board, IC, LSI, etc. by CAD.

[0002]

2. Description of the Related Art In a conventional interactive wiring method, a designer first specifies a line width and a clearance to be used as shown in FIG. 3 (step 31). The CAD calculates the distance between obstacles to be wired (step 32), and determines whether or not wiring with a designated line width and clearance is possible between obstacles (step 33). If the wiring is possible, the wiring is determined (step 35) and the arrangement is displayed (step 36). If wiring is not possible, the designer specifies the next line width or clearance (step 37), and again judges whether or not it is possible to wire the re-specified line width / clearance between obstacles (step 37). 34), the processing of steps 33, 34, and 37 was repeated until wiring was possible.

Further, in the automatic wiring method disclosed in Japanese Patent Laid-Open No. 60-254786, a wiring having a narrow line width is first formed, and then a wiring having a large line width is thickened.

[0004]

According to the conventional interactive wiring method described above, when wiring is not possible with the line width and clearance initially specified by the designer, the designer uses the next line width or clearance. I had to specify the next line width or clearance in consideration of whether to do it. As described above, the conventional interactive wiring method has a problem in that the designer has to repeatedly specify the line width and the clearance until wiring becomes possible, resulting in a large number of design steps. In the conventional automatic wiring method disclosed in Japanese Patent Laid-Open No. 60-254786, the clearance cannot be partially changed to a certain level or less.

[0005]

According to the interactive wiring designing method of the present invention, various line widths and clearances of wirings are prioritized in advance from the largest and stored in a priority library, and obstacles through the target wirings are stored. The distance between the objects is calculated, and it is determined whether or not it is possible to pass between the obstacles with respect to the wiring of the line width and the clearance read out from the priority library in the order of priority. It is characterized in that the line width and the clearance are read out and the determination is repeated, and the line width and the clearance when it is determined to be possible are determined as design values.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 is a diagram showing the contents stored in the computer by the interactive wiring design method according to the embodiment of the present invention. In this embodiment, the wiring library 22 has a line width unique I
D, the line width, and the display color are stored. The clearance library 23 stores the ID unique to the clearance, the clearance, and the display line type (solid line, broken line, etc.). The priority library 21 has line width and clearance IDs.
Are stored in order of priority. At that time, the values of the line type and the clearance are ordered so as to become smaller.

Next, FIG. 1 is a flow chart showing a wiring determining process according to an embodiment of the present invention.

First, the designer stores the respective information in the line width library 22, the clearance library 23 and the priority library 21 (steps 11, 12, 13).
The CAD calculates the distance between obstacles such as through-hole lands where the wiring whose width and clearance are to be determined should not be short-circuited (step 14), and the priority library 2
The first line width and clearance in 1 are applied (step 15). Next, it is judged whether or not it is possible to pass the wiring having the specified line width and clearance within the distance between the obstacles obtained previously (step 16), and if possible, the line width and clearance of the wiring are set. After determining (step 18), display color and display line type of the determined wiring are displayed (step 1).
9). The designer can know the determined line width and the determined clearance based on the display color of the wiring and the display line type.

If wiring is not possible, the next ID in the priority library is searched, the next line width or clearance is applied (step 20), and the possibility of wiring is judged (step 16).

Thereafter, until wiring is determined, step 16,
The processing of 17 and 20 is repeated.

[0012]

As described above, according to the present invention, it is not necessary for the designer to repeatedly input the limit values of the line width and the clearance, so that the number of design steps can be reduced. Further, by pre-storing the priority library, it is possible to adopt the line width of the minimum allowable limit according to a certain rule, and it is possible to improve the design quality.

[Brief description of drawings]

FIG. 1 is a diagram showing contents stored in a computer according to an embodiment of the present invention.

FIG. 2 is a flow chart showing an embodiment of the present invention.

FIG. 3 is a flowchart showing a conventional interactive wiring design method.

[Explanation of symbols]

 21 priority library 22 line width library 23 clearance library

Claims (1)

[Claims] 1. The various wiring line widths and clearances of wirings are prioritized in descending order and stored in a priority library, distances between obstacles passing through the wirings of interest are calculated, and the priority library is used in order of priority. It is judged whether it is possible to pass between the obstacles for the wiring of the read line width and clearance, and when it is judged impossible, the next line width and clearance is read again from the priority library and the judgment is repeated and judged as possible. An interactive wiring design method, characterized in that the line width and the clearance at the time of performing are determined as design values.