JPS635794B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for designing pattern connections on printed circuit boards. More specifically, the present invention relates to a method in which an electrical wiring pattern on a printed circuit board can be automatically designed by a computer (hereinafter simply referred to as a CPU).

A line segment search method (also referred to as a line search method) is generally known as one method for automatically designing electrical wiring patterns on printed circuit boards. This generally known line segment search method is such that the wiring pattern on one of the front and back sides of a printed circuit board is made up of only vertical lines, and the wiring pattern on the other side is made up of only horizontal lines. The wiring pattern is completed by connecting each pattern on the front side and the back side with through holes.

In this conventional line segment search method, the CPU calculates a large number of meshes (mesh-like areas) that partition the wiring area of a printed board with horizontal and vertical lines at certain intervals.
These meshes are connected and selected to form horizontal line segments or vertical line segments to form a wiring pattern.

The above-described conventional line segment search method for designing printed circuit board pattern connections has the following drawbacks. Since the wiring simply connects the meshes on the front and back sides of the printed board with horizontal and vertical straight lines, the pattern design processing speed is fast, but on the other hand, one pattern occupies many meshes. Therefore, the wiring rate was getting worse. That is, it cannot be applied to the design of printed circuit boards in which electronic components are incorporated at high density. Also, as mentioned above, the processing speed of pattern design is fast.
Since the route is searched for the entire wiring area of the printed board, there is room for further improvement in terms of processing speed.

The present invention has been made in view of the above points, and provides a printed board that further speeds up pattern design processing and can be applied to the design of printed boards in which electronic components are incorporated at high density. This paper attempts to provide a wiring connection design method.

The present invention is a line segment search method, and its gist is as follows. That is, a certain search width is set as an area for searching a route from a starting point to an ending point to be connected, and a connection pattern is specified within this limited area. Therefore, since it is necessary to search a narrower area than in the conventional example in which the entire wiring area is searched, the processing speed is further increased.

In addition, the connection pattern includes not only horizontal and vertical patterns, but also diagonal (approximately 45°) angled patterns to improve wiring efficiency.

The present invention will be explained in detail below based on the drawings.

FIG. 1 is a block diagram of an apparatus capable of creating printed board drawings using the printed board wiring connection design method according to the present invention. In the figure, 1 is a digitizer, 2 is a CPU, 3 is a memory,
4 is Protsuta. The device shown in Fig. 1 first uses digitizer 1 to determine the mounting positions of parts to be incorporated into the printed circuit board to be designed by CPU 2.
Enter. This input data is stored in the memory 3 via the CPU 2. In addition, the connection relationship between each component is also determined using input equipment (not shown).
Input to CPU2. Data regarding the connection relationship between each component is also stored in the memory 3 via the CPU 2. Next, the input device mentioned above (e.g. keyboard)
When a search width (described later) is input to the CPU 2 using
As shown in FIG. 1, a printed circuit board wiring diagram is automatically drawn by a plotter 4. The above is a summary of the operation of the present invention. Next, the present invention will be explained in detail using FIGS. 2 to 4.

In Figure 3, P ₁ is the starting point, P ₁₀ is the ending point,
The positions of P ₁ and P ₁₀ are input to the CPU 2 by the digitizer 1, as described above.
The operation up to specifying the pattern connecting P ₁ and P ₁₀ will be described below.

As described above, the present invention is a line segment search method, and the patterns on the front side and the back side of the printed board are used for vertical and horizontal lines, respectively. and,
Assume that the initial value of the search width input from the keyboard to the CPU is "3".

First, as shown in Figure 3, centering on the starting point _P1 ,
Proceed along a path with a search width of 3 in the direction of the axis. This search width 3 is defined by the lines Xm and Yn drawn along the X and Y axes.
It means the width of three meshes separated by . Then, number 1 is placed on the mesh where starting point P ₁ is placed.
Attach. Next, number 2 is assigned to meshes adjacent to the starting point _P1 in eight directions. A method of such numbering (mark sequence) is shown in FIG. In FIG. 2, P ₁ is the starting point as explained in FIG.
Mark sequence ₁ is attached to this starting point P1, then mark sequence 2 is attached to meshes in eight adjacent directions, and mark sequence 3 is attached to meshes in eight adjacent directions. Such numbering can be repeated in sequence until the desired end point is reached. In addition, in the conventional line segment search method, only meshes in four adjacent directions are numbered in the next stage, so it is not possible to design a pattern with an angle of 45 degrees, and high-density wiring cannot be achieved.

In this way, the search path is continued in the X direction in FIG. 3 while being numbered, and the search path in the X direction is advanced until it intersects with the search path taken from the end point _P10 . This X
It is assumed that the direction search path is on the front side of the printed board.

Next, starting from the center mesh _P2 at the intersection of the search path taken from the end point _P10 and the search path proceeding as described above from the start point _P1 , move toward the end point _P10 on the back side of the printed board. Proceed along the search path in the Y direction.
At this time, the mark sequence of mesh _P2 starts a new numbering as 1. Thereafter, the search path is advanced in the same order as on the front side until it reaches the end point _P10 .

When the meshes on which the end point P ₁₀ is placed are numbered as described above, by selecting and connecting the meshes of the search path that has been traveled so far, a pattern connecting the starting point P ₁ and the end point P ₁₀ can be created. means that exists. However, if the desired pattern connecting the starting point P ₁ and the ending point P ₁₀ is wide like the above-mentioned search path (width including 3 meshes in the example in Fig. 3), the wiring rate will be low. It has deteriorated and is no longer suitable for practical use.

Therefore, a pattern path consisting of one mesh having a unit width is specified by a reverse search as described below.

The reverse search operation is performed by returning from the end point _P10 to the start point _P1 on the search path traveled as described above. That is, the search path meshes numbered in three stages are followed in the reverse order of 3→2→1→3, and so on. The following rules are applied to this reverse search.

(1) If the same number is attached to multiple adjacent meshes, (a) Select the meshes so as to return in the direction from which the search route came, without making unnecessary changes in direction.

(b) Select the next mesh in order so as to approach the starting mesh.

Through the above procedure, the reverse search starting from the end point _P10 follows the route shown in FIG. 3 and reaches the point _P2 . At this point _P2 , a through hole is provided and the pattern is transferred to the front side of the printed board. Then, a pattern from point _P2 to starting point _P1 is formed as shown in FIG.

In this way, a search path of a certain width is provided from the starting point P ₁ to the ending point P ₁₀ , and then a reverse search is performed in which meshes on this search path are appropriately selected from the ending point P ₁₀ and returned to the starting point P ₁ . connection pattern is completed.

Note that if the search path from the starting point P ₁ to the ending point P ₁₀ cannot reach the ending point P ₁₀ because of a pattern that has already been wired on the route, the desired connection will not be possible in the area based on this search width. This means that no pattern exists, so the search is performed again with an even wider search width, and the above operations are repeated until the end point _P10 can be reached.

In addition, in the above explanation (especially the explanation of FIG. 2),
It has been explained that meshes in eight adjacent directions are numbered in the next stage, but when the search width is narrow as shown in Figure 3, numbering is done only within the search path.
The numbers advance in a band-like manner in the direction of travel of the search route.

In addition, in Figure 3, a hole is provided at point P ₂ for example to attach a part, so this point
If the connection pattern cannot pass through _P2 , the present invention results in a wiring pattern as shown in FIG. That is, the mesh (search path) is moved to the opposite side of the printed board starting from mesh _P3 in front of point _P2 , and numbered from there as shown in FIG. 4. Then, the reverse search starting from the end point P ₁₀ is
By making point _P4 a through hole as shown in Figure 4, the connection is transferred to the opposite side of the printed board.
The connection pattern reaches the starting point _P1 . As described above, in the present invention, since adjacent meshes in eight directions are numbered, a connection pattern having an angle of about 45 degrees can be formed, and a smooth pattern can be obtained. Therefore, the wiring rate is improved compared to the conventional line segment search method.

FIG. 5 is a diagram for explaining a specific example of searching for printed board wiring by the method of the present invention. In FIG. 5, G1 to G4 are like integrated circuits, and are composed of, for example, 8 pins. _P5 and _P6
are through holes, and l ₁ to l ₅ are already wired patterns. FIG. 5 shows a design example of a pattern connecting point P ₁ of integrated circuit G1 and point P ₁₀ of integrated circuit G3. In addition, in FIG. 5, an example in which the search width is set to 2 will be explained.

First, point _P1 is taken as the starting point, and the mesh on which point _P1 is placed is set in mark sequence 1. below,
As explained in FIG. 3, the search path is advanced to the right until it is interrupted by the already wired pattern _l1 . When it is interrupted by pattern _l1 , the search path moves to the opposite side of the printed board, and the search path moves upwards while starting from point _P8 and renumbering it. When this search path reaches the same position as the end point P ₁₀ ,
The search path moves to the opposite side of the printed board again, and the point
Starting from P ₇ , proceed along the search path to the right while renumbering it until you reach the end point P ₁₀ .

After the search path from the starting point P ₁ to the ending point P ₁₀ is drawn in this way, the reverse search is started from the ending point P ₁₀ . By making through holes at points _P7 and _P8 on the way, a pattern as shown in FIG. 5 is completed.

After going through the process described above and calculating the route of the pattern between two points to be connected one after another by the CPU, this pattern is visualized using a plotter connected to the CPU, and the design of the printed circuit board wiring is completed. do.

As described above, according to the present invention, the following effects can be obtained.

(b) By setting the search width, the search mesh can be limited, so the processing time by the CPU can be reduced.

(b) Connections can be made at an angle of approximately 45°, which improves wiring efficiency and allows for designs on high-density printed circuit boards.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus capable of creating printed board drawings using the printed board wiring connection design method according to the present invention, and FIGS. 2 to 4 are printed board wiring connection design according to the present invention. A diagram for explaining the method, FIG. 5 is a diagram for explaining a specific example of searching for printed board wiring by the method of the present invention. 1...Digitizer, 2...CPU, 3...Memory, 4...Programmer, P ₁ ...Start point, P ₁₀ ...End point,
G1 to G4... integrated circuits.

Claims (1)

[Claims] 1. The pattern on one of the front and back sides of the printed board is a vertical line including an oblique angle, and the pattern on the other side is a horizontal line including an oblique angle, and the pattern on the front side and the back side is a vertical line including an oblique angle. A method of designing pattern connections on a printed board by making connections between each pattern using through holes, and using a computer, applying the following steps between two points to be connected. (A) The process of inputting the mounting positions of parts to be installed on a printed board into a computer. (B) Process of inputting connection relationships between each component into a computer. (C) A process of setting the initial value of the search width for searching for a route from the starting point to the ending point to be connected. (D) A computer calculates a straight line search path having the above-mentioned initial search width on the front and back sides of the printed board, and creates a route from the starting point to the ending point while connecting the straight line search paths to both the front and back sides. The process of searching for information using a computer. Note that this search path is composed of rectangular meshes, and the meshes in eight adjacent directions are repeatedly numbered in three stages. Then, when one straight line search path is completed and the connection is moved to the opposite side of the printed board, the meshes on the opposite side at this moved point are sequentially numbered starting from 1. Furthermore, the search path avoids areas where wiring has already been completed. (E) If there is no route from the start point to the end point in the search in (D) above, the process in (D) above is repeated again with a wider search width. (F) A step of performing a reverse search by following the reverse order of the numbering on the search path searched in the above (D) from the end point to the start point.