JP2983368B2 - Wiring pattern design method and CAD system for wiring pattern design - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CAD (Computer Aid) used for designing a wiring pattern of a printed circuit board, for example.
ed Design) The present invention relates to a system and its wiring pattern designing method.

[0002]

2. Description of the Related Art Conventionally, when designing a wiring pattern of a printed circuit board using a CAD system, it is a principle that a wiring pattern is generated on a predetermined grid (hereinafter, referred to as a basic grid) in the CAD system. (Hereafter,
The wiring pattern generated on the basic grid is called a grid pattern. ). The spacing of this basic grid is generally 2.54 mm (0.1
Inches), but auxiliary grids may be set at intervals (for example, 0.635 mm, 0.508 mm, 0.3175 mm) obtained by dividing the number of divisions.

However, with the recent increase in the component mounting density of printed circuit boards due to the demand for smaller and higher density printed circuit boards, it has become necessary to generate wiring patterns that do not conform to the basic grid (hereinafter, referred to as “patterns”). A wiring pattern that does not fall on the basic grid is called a non-grid pattern.) For such a non-grid pattern, a method of generating a wiring pattern on the grid with a close grid interval, or a horizontal or vertical A method of generating a wiring pattern on a basic grid and thereafter generating a wiring pattern on a basic lattice have been adopted.

[0004]

By such a conventional method of generating a non-lattice pattern, the component mounting density of a printed circuit board can be improved to some extent.

However, the number of components currently used on printed boards has been diversified, and components having different terminal intervals have frequently been mixed on a single printed board. The grid pattern generation method has the following problems, and a method that can design a non-grid pattern more freely and more easily is desired.

In the method of generating a non-grid pattern by making the grid interval close, the search efficiency is high because the optimum pattern is searched using the basic grid, but the terminals of the components used are all present on the grid. In addition, the wiring pattern must be generated while the operator is always aware of the grid, and the grid interval is frequently changed.

[0007] In the method of generating a horizontal or vertical pattern such that the pattern extends on at least one of the grids in the X direction or the Y direction at the time of extraction, when the shape of the component terminal is other than a round shape (rectangular, long round, etc.) In this case, it is only necessary to pull out in a direction along the shape of the terminal. However, in the case of a round shape, the drawer direction does not necessarily have to be horizontal or vertical, so that there is a problem that the operability is deteriorated by limiting the drawer direction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wiring pattern designing method which can easily design a wiring pattern of a printed board including a non-lattice pattern.

It is a further object of the present invention to provide a CAD system in which a wiring pattern of a printed circuit board including a non-grid pattern can be easily designed.

[0010]

In order to achieve the above object, a method of designing a wiring pattern according to the present invention comprises the steps of: determining a starting point of a wiring pattern on a screen ; in the step of indicating a point directed against the starting point is, when in the position capable of forming a rectangle and these diagonal points with a horizontal (X-direction) edges and vertical (Y-direction) sides Between the start point and the designated point, a long side line segment that goes straight along the long side of the rectangle from one of the points, and an angle set in advance with respect to the side in the X direction from the other point. Generating a wiring pattern formed by combining the oblique line segment leading to the long side line segment.

According to the present invention, there is provided a wiring pattern designing method for determining a starting point of a wiring pattern on a screen.
And the point to draw the wiring pattern from this starting point
And the point specified for the starting point
Form a rectangle with horizontal and vertical sides as diagonals
Between the start point and the designated point
The long side line segment of the rectangle and the start point for the long side line segment
Or the combination with the shaded line segment from the point specified.
A step of setting rules for forming a line pattern;
Between the starting point and the indicated point according to the established rules
And a step of generating a wiring pattern .

[0012]

[0013] CAD systems for designing a wiring pattern of the present invention, in the drawing displayed on the screen, and a wiring section specifying means for instructing the wiring end point and the wiring start point of the wiring pattern, the wiring start point or line Wiring pattern at end point
Instructing means for instructing a point to be drawn on the grid, and a horizontal (X-direction) side and a vertical (X-direction) side between any two points between the wiring start point and the wiring end point as diagonal points. When at a position where a rectangle having a side (in the Y direction) can be formed, a long side line segment that goes straight along the long side of the rectangle from one point and a side in the X direction from the other point A wiring pattern generating unit configured to generate a wiring pattern formed by combining the oblique line segment reaching the long side line segment at a preset angle.

[0014]

Further, according to the present invention, in the CAD system, the wiring pattern generating means reads designated points on the screen arbitrarily designated points, and the line segment drawn from the wiring starting point is a long side line. Draw-out wiring pattern generation rule that determines whether the line segment is a line segment or a diagonal line, a pull-in wiring pattern generation rule that determines whether the line segment drawn into the wiring end point is a long side line or a diagonal line, and A wiring pattern generation rule setting means for setting an angle of a diagonal line with respect to a side in the X direction; and a wiring start point or, if a wiring pattern has already been generated from the wiring start point, an end point of the wiring pattern as a start point. If the start point is a wiring start point between the start point and the designated point read by the designated point reading means, the drawing set by the wiring pattern generation rule setting means A dummy wiring pattern is generated according to the wiring pattern generation rule at the time, and when the designated point coincides with the wiring end point, a dummy wiring pattern is generated according to the wiring pattern generation rule at the time of pull-in set by the wiring pattern generation rule setting means. Dummy wiring pattern generating means, wiring pattern determining means for determining the generated dummy wiring pattern as a wiring pattern, and, when the designated point when the wiring pattern is determined is not the wiring end point, storing the designated point as a determined point Further, it is characterized by comprising a fixed point storage means for notifying the dummy wiring pattern generation means as a starting point of the subsequent wiring pattern.

Further, according to the present invention, in the CAD system, a pattern check condition setting means for setting a permissible value of a gap between respective elements on the drawing as a pattern check condition, and based on the set pattern check condition,
Wiring pattern checking means comprising pattern checking means for determining whether the dummy wiring pattern generated by the dummy wiring pattern generating means has a gap equal to or larger than an allowable value with other elements. I do.

[0017]

In the wiring pattern designing method and the wiring pattern designing CAD system according to the present invention, only one point is specified for a certain point, and if necessary, a line segment in the X direction or the Y direction can be formed at a predetermined angle. A wiring pattern composed of inclined line segments can be generated between two points. Therefore, even when the terminal serving as the wiring start point is not on the grid, the non-grid pattern can be easily formed between the wiring start point and the specified point by placing the designated point on the grid, preferably at the intersection of the grid. Generate
Thereafter, a wiring pattern can be designed along the lattice. Similarly, even when the wiring end point is not on the grid,
Just by placing the designated point at the wiring end point, the non-grid pattern can be easily drawn into the wiring end point. At this time, by selecting a line segment drawn from the wiring start point and a line segment drawn into the wiring end point, a wiring pattern suitable for the position and shape of each terminal serving as a wiring start point and a wiring end point is generated. be able to.

Further, the CAD for designing a wiring pattern according to the present invention
In the system, the wiring start point and the wiring end point to be connected are determined by the wiring section designating means, and when the wiring pattern is drawn from the wiring starting point by the wiring pattern generation rule setting means, and when the wiring pattern is set at the wiring end point of the wiring section. Is set, a rule for generating each wiring pattern is set. Then, the position information of the point pointed by the pointing device such as a mouse is fetched by the point reading means, and the starting point is the wiring start point by the dummy wiring pattern generating means, that is, the fixed point is not stored in the fixed point storing means. At the time of pulling out, or when the designated point coincides with the wiring end point, it is inclined at a predetermined angle with the line segment in the X direction or Y direction as necessary according to the respective wiring pattern generation rules at the time of pulling in. A dummy wiring pattern composed of line segments is generated between a wiring start point or a fixed point and a designated point. The shape of the dummy wiring pattern generated by the dummy wiring pattern generating means changes according to the movement of the designated point by the pointing device. However, when the wiring pattern determining means determines the dummy wiring pattern, the dummy wiring pattern is determined as the wiring pattern. The designated point at that time is stored as a fixed point by the fixed point storing means. The stored fixed point is notified to the dummy wiring pattern generation means as the starting point of the next dummy wiring pattern. In this way, when the wiring patterns are sequentially generated and determined between the start point and the designated point, and the wiring patterns are generated at the wiring start point and the wiring end point, the wiring section designating means performs the next wiring. The start point and the wiring end point are designated, and the above-described generation of the wiring pattern is repeated.

For this reason, the operator looks at the screen,
A suitable wiring pattern according to the position and shape of each terminal to be connected and the arrangement of other patterns on the substrate can be freely and easily designed without being bound by the basic grid.

Further, in the CAD system, a pattern check condition setting means for setting a pattern check condition comprising an allowable value of a gap between each element on the substrate, and a pattern check condition set by the pattern check condition setting means. Based on the above, by providing a pattern check means for checking the dummy wiring pattern whether the gap between the dummy wiring pattern generated by the dummy wiring pattern generating means and other elements is not less than an allowable value,
The operator can immediately confirm whether or not it interferes with another obstacle element while the dummy wiring pattern is being generated while looking at the screen. Therefore, it is possible to efficiently design a wiring pattern having no wiring failure.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a CAD system for designing the arrangement and wiring of components on a printed circuit board according to the present invention. The display 1a, an input device 1b such as a keyboard and a mouse, a storage device 2, It is composed of a component layout design unit 3, a wiring pattern generation unit 4, and a wiring pattern check unit 5. Display 1a
Displays information necessary for designing a wiring pattern such as a component layout diagram of a board, and an input device 1b is a means for inputting information necessary for the design based on screen information displayed on the display 1a. The storage device 2 stores data necessary for the layout design of components on a board, the design of wiring patterns, and the like. Based on the data in the storage device 2, an optimal board layout diagram is stored in the component layout design means 3. Created by The wiring pattern generating means 4 arbitrarily designates information input via the input device 1b, such as a wiring start point and a wiring end point, on the component layout drawing created by the component layout design means 3 and between them. A wiring pattern is generated between the wiring start point and the wiring end point based on the coordinate information of the point to be connected. The wiring pattern checking means 5 has a function of checking whether the wiring pattern generated by the wiring pattern generating means 4 has a sufficient distance from other elements on the substrate.

In designing a wiring pattern using such a CAD system, first, the display 1a
Then, a component layout diagram of, for example, a printed wiring board as shown in FIG. 2 is displayed. The component layout diagram of such a wiring board includes a library 2a that stores information on the shape and the number of terminals of components stored in the storage device 2 in units of components,
A net list 2b for storing information such as component names and connection signal information between mutual terminals, and a design rule file 2c for storing information such as a laminated structure of boards, allowable values of mutual gaps between mounted components and wiring patterns, and grid intervals. The data is automatically designed and displayed according to the component layout design means 3 based on the data. Such automatic component placement design is, for example, RACAL-REDAC's
It has already been realized by VISULA software. Then, in the component layout diagram of this board, the terminals to be connected and the terminals are respectively connected by straight lines (dotted lines in the figure) and displayed based on the connection signal information between the mutual terminals of the netlist 2b. Also, a grid 6 serving as a design reference is displayed.

A wiring pattern is designed interactively based on the component layout of the board displayed on the display 1a. The design process is described below with reference to FIGS.
This will be described with reference to FIG. Here, FIG. 3 shows the wiring pattern generating means 4 and the wiring pattern checking means 5 of FIG.
C for wiring pattern of the present invention showing the function of
FIG. 4 shows an example of an AD system, and FIG. 4 is a diagram illustrating a wiring pattern generation step.

First, as shown in FIG. 2, when an unconnected path 7 to be wired is selected from an unconnected path whose wiring pattern has not been determined using a pointing device such as a mouse, the wiring section designating means 8 The end point of the unconnected path 7 which is close to the pick cursor 10 pointed by the pointing device at a straight line distance is recognized as a wiring start point 12 and the other end point is recognized as a wiring end point 14 and notified to a dummy wiring pattern generation means 16 described later. I do.

The wiring start point 1 is determined by the wiring section designating means 8.
2 and the wiring end point 14, the designated point reading means 18 reads the coordinate information of the point 20a arbitrarily designated by the operator using a pointing device such as a mouse, and generates the dummy wiring pattern generating means as information of the designated point 20a. 16 to provide.

The dummy wiring pattern generating means 16 first compares the input designated point 20a with the wiring end point 14 provided by the wiring section designating means 8, and if no match is detected, the wiring starting point 12 and the designated point 20a In between, a dummy wiring pattern is generated in accordance with a wiring pattern generation rule at the time of extraction set in advance by a wiring pattern generation rule setting means 24 described below.

As shown in FIG. 4, the wiring pattern generation rule at the time of extraction is such that when a point 20a that is not in the X or Y direction with respect to the wiring start point 12 is designated, the wiring pattern to be generated is the pattern 26. Or the pattern of reference numeral 28. The wiring pattern denoted by reference numeral 26 assumes a rectangle 30 having a side in the X direction and a side in the Y direction with the wiring starting point 12 and the designated point 20a as diagonal points.
2, a line segment 26a is generated on the long side, and a line segment 26b is generated from the line segment 26a to the designated point 20a at a predetermined angle, for example, a 45 ° inclination with respect to the side in the X direction. Sign 2
The wiring pattern 8 generates a line segment 28a at an inclination of, for example, 45 ° from the wiring start point 12, and generates a line segment 28b along the long side at the point where the rectangle 30 hits the long side to the designated point 20a. Become. If the former wiring pattern 26 is defined as the long side mode and the latter wiring pattern 28 is defined as the short side mode, the wiring pattern generation rule at the time of drawing out is defined in the wiring pattern generation rule setting window 31 as shown in FIG. By selecting one of the long side and the short side in the drawer column of the menu 33 of the wiring item 32, the setting is made in the pattern generation rule setting means 24. The inclination of the line segments 26b and 28a is determined by writing the angle in the menu of the grid item 34 in the window 31. The angle of this line segment can be set arbitrarily in the range of 0 ° to 90 °. The screen data of the wiring pattern generation rule setting window 31 is created in the wiring pattern generation rule setting means 24 based on the data in the storage device 2 and called up on the display 1a in response to an operator's request. Is displayed as a wiring pattern generation rule setting window 31 separately from the application screen. The mode of the wiring pattern at the time of drawing out can be selected according to the shape of the component terminal, which is the wiring starting point 12, and the like. In the example of FIG. 4, since the terminal at the wiring start point is oval, the long side mode is selected.

In this manner, the dummy wiring pattern generation means 16 sets the code between the wiring start point 12 and the designated point 20a in accordance with the wiring pattern generation rule at the time of drawing set in the wiring pattern generation rule setting means 24. 26 dummy wiring patterns are generated. At this time, the designated point 20a
Is taken on the grid 6, more preferably at the intersection, if the wiring start point 12 is not on the grid 6, a vertical line segment can be easily drawn from the wiring start point 12 and drawn on the grid 6, and Can be generated along the grid 6.

The rubber band display control means 42 displays the dummy wiring pattern generated by the dummy wiring pattern generating means 16 on the display 1a. At this time, if the dummy wiring pattern has already been displayed, the existing dummy wiring pattern is first erased, and a new dummy wiring pattern is displayed. Therefore, the dummy wiring pattern generated by the dummy wiring pattern generating means 16 is displayed on the display 1a like a rubber band in real time by the rubber band display control means 42 in accordance with the movement of the designated point 20a. For this reason, the operator moves the pointing device while moving the pointing point 20.
By taking "a" on the grid 6, for example, at the intersection of the grid 6, a suitable pattern can be searched for.

At the same time, the pattern checking means 44 determines whether the dummy wiring pattern generated by the dummy wiring pattern generating means 16 has a sufficient gap with other pattern elements based on a preset pattern checking condition. Is notified to the operator by, for example, a color display, a buzzer, a message, or the like.

The pattern check conditions are set in advance by the pattern check condition setting means 46. For example, as shown in FIG. 6, a pattern check condition is set by designating, via a pattern check condition setting window 61, a numerical value of an allowable distance between a wiring pattern and each element that becomes an obstacle of the pattern. In the example of FIG.
PAD-PAD, PAD-VIA, VIA-VIA
, PAD-LINE, VIA-LINE, LIN
Each allowable gap value between E-LINE is called and set from the design rule file 2c. The screen data of the pattern check condition setting window 61 is created by the pattern check condition setting means 46 based on the data of the storage device 2 and is displayed as the pattern check condition setting window 61 instead of the wiring pattern generation rule setting window 31. 1a.

The pattern checking means 44 firstly forms a space of the gap allowance around each element 71 based on the gap allowance between the elements set in the pattern check condition setting means 46, as shown in FIG. Figure 7 with 72
Assuming 3 and dividing the substrate into meshes of a predetermined size,
By calculating the distance between the figures 73 in the mesh for each mesh and determining the presence or absence of the intersection, it is determined whether or not the interval is sufficiently maintained.

The wiring pattern determining means 74 is means for determining the dummy wiring pattern displayed on the screen via the rubber band display control means 42. When an operator inputs a determination signal, the pattern checking means 74 The dummy wiring pattern passed through 44 is determined as a wiring pattern, and is displayed on the display 1a via the wiring pattern display means 76.

The determined point storing means 78 stores the determined designated point 2
The coordinates of 0a are stored and notified to the dummy wiring pattern generation means 16 as the starting point of the wiring pattern to be generated next.

As described above, when the wiring pattern is determined between the wiring starting point 12 and the designated point 20a, the pointing device arbitrarily specifies the next starting point from the determined point 20a which is the previous designated point. Between the point 20b and the wiring pattern generation rule setting means 24, a dummy wiring pattern is generated according to the wiring pattern generation rule at the time of drawing. Usually, it is easier to design a wiring pattern along the grid 6, so that the designated point 20b is obtained on the same grid line as the fixed point 20a, and a horizontal wiring is provided between the fixed point 20a and the designated point 20b. A pattern 80 is generated.

When the horizontal wiring pattern 80 is fixed, the designated point 20b is rewritten as a new fixed point in the fixed point storage means 22, and the fixed point 20b and the next designated point 20 are rewritten.
c, a wiring pattern is generated.

Here, when the wiring device 14 designates the wiring end point 14 with a pointing device, the dermy wiring pattern generation means 16 detects that the designated point 20c coincides with the wiring end point 14, and sets the wiring pattern generation rule setting means 24.
A dummy wiring pattern of the long side mode 82 or the short side mode 84 is generated in accordance with the wiring pattern generation rule at the time of pull-in set in advance. In this case, the long side mode and the short side mode are determined based on the designated point which is the wiring end point. The wiring pattern generation rule at the time of drawing in is set in the wiring pattern generation rule setting window 31 similarly to the wiring pattern generation rule at the time of drawing. Wiring end point 1
If the terminal 4 is an oval terminal, the long side mode for drawing a vertical line segment is selected.

As described above, when the fixed point is not stored in the fixed point storage means 78, the dummy wiring pattern generation means 16 recognizes the wiring start point 12 as the starting point, and makes the fixed point storage means 78 determine. When the point is stored, the determined point is recognized as a starting point, and a dummy wiring pattern is generated between the starting point and the designated point.

It has been described that the wiring pattern generated between the fixed point 20a and the designated point 20b which is not the wiring end point complies with the generation rule at the time of drawing out. Is also good.

Through the above wiring pattern generation step,
Between the wiring start point 12 and the wiring end point 14, for example, FIG.
Then, a wiring pattern indicated by a thick line is generated. When the wiring pattern between one wiring start point and the wiring end point is determined, the next wiring section is selected by the wiring section designating means 8, and thereafter, the wiring pattern is designed in the same manner as shown in FIG. Such a wiring pattern design drawing is obtained. .

As described above, according to the present invention, it is possible to design a wiring pattern in accordance with the terminal shape of a component used on a printed circuit board, and to design a wiring pattern from a component terminal that is not on a lattice. It is possible for an operator to design a non-grid pattern without being conscious of the basic grid. Further, by performing a pattern check at the stage of generating a dummy wiring pattern, it is possible to efficiently design a suitable pattern without wiring defects.

In the above embodiment, the function of performing the pattern check after the generation of the dummy wiring pattern is provided. However, the pattern check may be performed after the design of all the wiring patterns is completed.

In the above-described embodiment, the wiring pattern generation rule is set in advance, and either the long side mode or the short side mode is generated and displayed on the display. After displaying both the dummy wiring patterns in the short side mode on the display, the operator can select either one of the patterns.

[0044]

As described above, according to the present invention,
It is possible to freely and efficiently design a wiring pattern including a non-lattice pattern, and it is possible to sufficiently meet the demand for miniaturization and high density of a printed circuit board.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration example of a CAD system for designing component placement and wiring according to the present invention.

FIG. 2 is a diagram illustrating a component layout diagram of a board and a method of specifying a wiring section;

FIG. 3 is a block diagram showing an embodiment of a CAD system for designing a wiring pattern according to the present invention.

FIG. 4 is a diagram illustrating a method of generating a wiring pattern in steps;

FIG. 5 is a diagram showing a wiring pattern generation rule setting window.

FIG. 6 is a diagram showing a pattern check condition setting window.

FIG. 7 is a diagram illustrating a method of checking a pattern.

FIG. 8 is a diagram illustrating a wiring pattern on a substrate designed according to the present invention.

[Explanation of symbols]

 2 ... storage device 3 ... component arrangement design means 4 ... wiring pattern generation means 5 ... wiring pattern checking means 6 ... lattice 7 ... unconnected path 8 ... wiring section designation means 10 Pick cursor 12 Wiring start point 14 Wiring end point 16 Dummy wiring pattern generating means 18 Designated point reading means 20 Designated point 24 Generating wiring pattern Rule setting means 26... Wiring pattern in long side mode at the time of drawing out 28... Wiring pattern of short side mode at the time of drawing out 31... Window for setting wiring pattern generation rule 42... Rubber band display control means 44 ... Pattern check means 46 ... Pattern check condition setting means 61 ... Pattern check condition setting window 74 ... Wiring pattern determination means 7 6: Wiring pattern display means 78: Fixed point storage means 82: Wiring pattern of long side mode at the time of retraction 84 ... Wiring pattern of short side mode at the time of retraction

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-161569 (JP, A) JP-A-3-204777 (JP, A) JP-A-2-42580 (JP, A) JP-A-62-162 291998 (JP, A) JP-A-62-269338 (JP, A) JP-A-62-194579 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06F 17/50 H01L 21 / 82 H01L 23/52

Claims (5)

(57) [Claims] 1. A step of determining a starting point of a wiring pattern on a screen, and a step of drawing a wiring pattern to the starting point on a grid.
In the step of indicating in the point directed against the starting point, (the X direction) and these diagonal points horizontal edges and vertical (Y
When the position is such that a rectangle having sides (in the direction) can be formed, a long side line segment that goes straight along the long side of the rectangle from any one point between the start point and the designated point, and the other X from the point
Generating a wiring pattern formed by combining a slanted line segment extending to the long side line segment at a preset angle with respect to a side in the direction. 2. A starting point of a wiring pattern is determined on a screen.
And the point where the wiring pattern is drawn from this starting point.
And the point designated for the starting point
Form a rectangle with horizontal and vertical sides diagonally
When it is in a position that can be formed, the start point and the point indicated
The distance between the long side line segment of the rectangle and the long side line segment is
Point or a combination with a diagonal line from the designated point.
Of setting rules for forming wiring patterns
And the point designated as the starting point according to the set rules.
Generating a wiring pattern between the two . 3. A wiring section designating means for designating a wiring start point and a wiring end point of a wiring pattern on a drawing displayed on a screen, and a wiring pattern at the wiring start point or the wiring end point.
Instruction means for instructing a point on the grid on which to pull in the wiring, and a horizontal (X-direction) side and a diagonal point between any two points between the wiring start point and the wiring end point. When located at a position where a rectangle having a vertical (Y-direction) side can be formed, a long-side line segment that goes straight from one of the points along the long side of the rectangle, and a side in the X-direction from the other point And a wiring pattern generating means for generating a wiring pattern formed by combining a slant line segment extending to the long side line segment at a predetermined angle with respect to the wiring pattern design CAD.
system. 4. A CAD system according to claim 3 , wherein said wiring pattern generation means reads designated points on the drawing at a designated point, and a line segment drawn from the wiring start point is a long side line. Draw-out wiring pattern generation rule that determines whether the line segment to be drawn is a long side line or a diagonal line, And a wiring pattern generation rule setting means for setting an angle of a diagonal line with respect to a side in the X direction, and a wiring start point or an end point of the wiring pattern if a wiring pattern has already been generated from the wiring start point. Between the starting point and the designated point read by the designated point reading means, when the starting point is the wiring starting point, the wiring pattern generation rule A dummy wiring pattern is generated according to the wiring pattern generation rule at the time of drawing set by the setting means, and when the designated point coincides with the wiring end point, the wiring at the time of drawing set by the wiring pattern generation rule setting means is generated. A dummy wiring pattern generating means for generating a dummy wiring pattern in accordance with a pattern generation rule; a wiring pattern determining means for determining the generated dummy wiring pattern as a wiring pattern; and a designated point when the wiring pattern is determined is not a wiring end point. A CAD system for designing a wiring pattern, comprising: a fixed point storing unit that stores the coordinates of the designated point as a fixed point and notifies the dummy wiring pattern generating unit as a starting point of a subsequent wiring pattern. 5. The CAD system according to claim 3 , wherein
An indication point reading means for reading an arbitrarily designated point on a screen, and a wiring pattern generation means for determining whether a line segment drawn from a wiring start point is a long side line segment or an oblique line segment A wiring pattern generation rule, a drawing-time line wiring pattern generation rule for determining whether a line drawn to a wiring end point is a long side line or a diagonal line, and an angle of a diagonal line with respect to a side in the X direction are set. The wiring pattern generation rule setting means and the wiring start point or, if a wiring pattern has already been generated from the wiring start point, the start point of the wiring pattern is set as an end point, and the start point and the designated point reading means are read. When the starting point is the wiring start point between the designated wiring point and the designated wiring point, the wiring pattern at the time of drawing set by the wiring pattern generation rule setting means is set. A dummy wiring pattern is generated according to a generation rule, and when the designated point coincides with a wiring end point, a dummy wiring pattern is generated according to a wiring pattern generation rule at the time of attraction set by the wiring pattern generation rule setting means. A pattern generating means, a wiring pattern determining means for determining the generated dummy wiring pattern wiring pattern,
When the designated point when the wiring pattern is determined is not the wiring end point, saves the coordinates of the specified point as a determined point, and notifies the dummy wiring pattern generating means as a starting point of a subsequent wiring pattern to the determined point storage means. CAD system for designing a wiring pattern, wherein ingredients Bei to Rukoto a.