JPS5972567A - Designing device of printed base board - Google Patents

Abstract

PURPOSE:To decentralize the density of arrangement and to reduce the total wiring length, by arranging the unarranged parts having their centroids deflected toward the adjacent region in order of larger deflection, accordingly, arranging the unarranged part of other regions. CONSTITUTION:A key input device 3, a CRT picture display device 4, a photoplotter 5 and a tape puncher 6 of a tablet 1, a keyboard 2, etc. are connected to a central processor 8 via an I/O port 7. At the same time, a storage device 9 is connected to the processor 8. The processor 8 divides a printed base board into plural blocks (regions) based on the parts information of the base board which is given from the device 3. Then the parts are arranged so as to obtain the minimum number of wiring connections between blocks. The diagram of this arrangement is recorded to the processor 9 and displayed to the device 4 and also delivered to the plotter 5 as a photomask.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a CAD (Computer Aided
The present invention relates to a printed circuit board design device, and particularly to a printed circuit board design device that automatically arranges components on a printed circuit board, designs print patterns, etc.

Conventionally, automatic design equipment for designing printed circuit boards using CAD has been known, and this equipment automatically determines the placement position of components on the printed circuit board and creates print patterns, reducing the amount of time required for designing printed circuit boards. This reduces labor and time.

The center-of-gravity method is known as a method for arranging printed circuit board components using this automatic design device.

This center-of-gravity method is based on one part of the wiring that interconnects the components on the board.
A virtual tension is applied to the straight line distance from the starting point to the ending point for each book, and the position where the composite vector of the tension from all other parts to a certain part is zero (hereinafter, this position is referred to as the "center of gravity"). This is a wiring method in which the total virtual wiring length of the wiring is shortened by repeatedly performing the process of finding the center of gravity of the wiring and arranging the component at the center of gravity for each component.

The advantages of this wiring method include that it can be applied regardless of the shape and size of the component, and that the total wiring length on the board can be substantially shortened. On the other hand, the disadvantage is that the wiring density on the board is concentrated in a local area such as the center of the board, so the placement density in that local area increases, and terminals that cannot be connected to the component during automatic wiring performed after component placement. There is a great danger that this will occur.

Therefore, an arrangement method is required to disperse this wiring density. This method involves dividing the components into multiple groups based on their different connection strengths, then dividing the printed circuit board into the same number of areas as the number of groups, assigning each component group to an appropriate area, and then It is known to arrange individual parts within a region. However, with this method, parts placement within a certain area is performed by focusing only on the mutual positional relationship of the parts within that area, so it is not possible to appropriately reflect the mutual positional relationship with parts in other areas. . For this reason, it cannot be said that distribution of placement density and shortening of total wiring length are necessarily performed appropriately.

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to appropriately reflect the positional relationship between components even between different areas of a printed circuit board, thereby dispersing the placement density and improving overall It is an object of the present invention to provide a printed circuit board design device capable of designing to shorten wiring length.

The feature of the present invention is that the central processing unit
Calculate the center of gravity of all unplaced parts on the printed circuit board assuming that each unplaced part is placed at the physical center position of the area where the unplaced part should be placed, For unplaced parts in a certain area, the unplaced parts whose center of gravity is shifted toward the area adjacent to that area are placed closer to the adjacent area in the order of the degree of deviation, and the above placed position is set as the actual placement position of the part. The center of gravity of the remaining unplaced parts is calculated again, and the process of arranging the unplaced parts in other areas using the same procedure as above is repeated based on this recalculated center of gravity to place all parts. It's because of what happened.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

The device of this embodiment includes a keypad device 3 such as a tablet 1 and a keyboard 2, a CRT image display device 4, a photoplotter 5, and a tape puncher 6, each of which is connected to an I/O device.
10 ports 7 to a central processing unit 8, and a storage device 9 is further connected to this central processing unit 8. This central processing unit 8 divides the printed circuit board into a plurality of blocks (areas) according to the component information on the printed circuit board given from the key human power device 3, and arranges the components so that the number of wiring connections between each block is minimized. , the arrangement results are recorded in a storage device 9, further displayed on a CRT image display device 4, and outputted to a photoplotter 5 as a photomask.

Next, an embodiment of a design operation procedure for arranging components on a printed circuit board by the central processing unit 8 of this embodiment apparatus will be described.

First, initial division is performed and the next operation is performed.

As shown in FIG. 2, it is assumed that the printed circuit board 20 is placed in the first quadrant on the XY orthogonal coordinates, and the printed circuit board 20 is divided into four parts by vertical and horizontal lines passing through the center 20a. Block 2 (h) is divided into blocks 202, 203, and 204. Parts that are connected to the terminals of the connector 21 and fixed parts in each divided block are assigned to each block. Each block takes into its own block one by one the component for which the component group requested the most connection, that is, the component that has the largest number of connections with these component groups, and divides all components evenly into four blocks. Divide into.

Next, a description will be given of the inter-block component movement of the components initially divided as described above.

For the parts that have undergone initial division, a block/component quantity and connection number table as shown in FIG. 3 is created. This connection number table arranges each component in the horizontal direction and the block to which the component belongs in the vertical direction. Write the number of connections with the product. In this case, block 201 and pro-tsuk 203, or block 202 and pro-tsuk 2
04, blocks located at diagonal positions are weighted by multiplying the number of connections by a coefficient.

Check the number of wires between the parts' pro-to-blocks using this connection number table, and select parts for which the number of wires between pro-to-blocks will be reduced if you move from the pro-to-lock to which it currently belongs to another block. Move to the other pro-tsuku mentioned above. When moving parts, if the maximum allowable number of parts in the destination block is exceeded, find a part in the block that can reduce the number of connections by moving it to another block, and move that part to another block. Move to another block. By repeating this process and dividing the parts into blocks, the number of connections between each block can be minimized.

Next, the arrangement of components within each block after the inter-program component movement has been completed as described above will be explained.

First, the operation of arranging components within block 201 will be described using FIG. 4. Each block 201-2
The center coordinates 20b to 20e of block 201 are found, and the centers of gravity of all the parts in block 201 are found assuming that the terminal coordinates of the unplaced parts of each block are located at these positions. In addition, block 202.2 adjacent to block 201
Slots 23a~ of components to be placed on the border with 04
23h will be provided. Next, from all the parts in the block 201, parts whose center of gravity is biased toward the block 204, that is, parts whose Y coordinate value of the obtained center of gravity is large, are extracted by the number of slots 23a to 23e at the boundary with the block 204. . The extracted parts are arranged from the block 202 side in descending order of the X-coordinate value of the center of gravity, that is, the parts that are more biased towards the block 202. Similarly, components with large X coordinate values of the center of gravity are taken out in the number of slots 23f to 23h at the boundary with the block 202, and these components are arranged from the block 204 side in descending order of the Y coordinate value of the center of gravity.

Next, parts placement in block 202 is performed by the same process as described above. However, in this case, to find the center of gravity of all parts in block 202, it is assumed that the parts placed in block 201 are in their actual positions, and the terminal coordinates of the remaining unplaced parts are determined in the remaining part of block 201. center coordinates 2
Move to 0f and perform calculation. This results in block 2
When arranging parts in block 02, the arrangement state of parts in block 201 is reflected.

Thereafter, similar processing is repeated for blocks 203 and 204, and for parts that have already been placed, the center of gravity of each part is calculated again using the placement position as the absolute position, and specific placement is performed for the parts in each block.

After completing the first intra-block component placement for blocks 201 to 204 as described above, next slots on the outside (in the direction away from the center 20a) of each block 20 to 204 for which component placement has not yet been performed are performed. The same process is repeated for the outer slots, and the arrangement of all the parts is completed by repeating the same process for the outer slots. .

In this way, by recalculating the center of gravity of unplaced parts every time the placement position of some parts is determined, the mutual positional relationship of individual parts, especially the positional relationship with parts of other blocks, can be calculated when placing parts. - It can be reflected in seconds.

Although this embodiment describes the component arrangement when a block is divided into four, the present invention is not limited to this, and can generally be applied to cases where a printed circuit board is divided into a plurality of areas. be.

In this way, the device of the present invention arranges components on a printed circuit board in accordance with the following steps (a) to (v), thereby appropriately reflecting the relationship between the arranged components and automatically wiring later. This improves the wiring rate.

(a) Divide the components arranged on the printed circuit board into multiple groups based on the difference in the number of wiring connections.

(b) Divide the printed circuit board into the areas of the above number of groups.

(c) Allocate the components of the groups to the regions, and move the components between the regions so that the number of wiring connections between the regions is minimized.

(d) 2. Find the physical center position of each area, and assume that all unplaced parts in that area are placed at this center position.

(e) Find the center of gravity of all unplaced parts in a certain area.

(f) For each of the adjacent areas on the two sides adjacent to one area above, among all the unplaced parts in (b) above, the parts whose center of gravity is shifted toward the adjacent area are ranked in descending order of the degree of shift. The number uJ to be arranged along the boundary with the adjacent area is extracted.

(G) Place parts whose centers of gravity are offset toward the adjacent region along the boundary with one of the adjacent regions, and the degree to which the centers of gravity of these components are offset toward the other adjacent region is determined from that other adjacent region. The degree of this decreases as the distance increases.

(d) The placed parts placed according to (g) above are assumed to have been placed at that position, and the remaining unplaced parts in that area are assumed to be placed at the center position of the unplaced part of that area. Virtualize.

(S) Repeat steps (E) and (H) above for all remaining areas where parts have not yet been placed.

(J) For the remaining unplaced parts in each region, the remaining unplaced parts are placed by repeating the steps in (e) to (k) above, and all the parts are placed.

As explained below, according to the present invention, parts can be divided into a plurality of placement areas to avoid local concentration of placement density, and when placing parts within each placement area, white areas and other areas can be Since the placement position state of the components is appropriately reflected, the wiring density can be further distributed and the total wiring length can be shortened, and furthermore, the automatic wiring performed after this component placement can be performed efficiently. I can do it.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a printed circuit board block dividing method. FIG. 3 is a diagram illustrating a block/component quantity/connection number table. FIG. 4 is a diagram illustrating the arrangement of components within each block of the printed circuit board. 3... Key human power device, 4... CRT image display device,
5... Photoplotter, 8... Central processing unit, 9.
...Storage device, 20...Printed circuit board, 201-20
4...Block. Patent Applicant Yokogawa Electric Corporation Representative Patent Attorney Naotaka Ide

Claims (1)

[Claims] (1) a key manual device, a CRT image display device, a photoplotter, a central processing unit that is coupled to and controls the key device, the CRT image display device, and the photoplotter, respectively; and a storage device connected to the processing device, and the central processing device divides the printed circuit board into a plurality of regions according to the component information on the printed circuit board given from the key human power device, and divides the printed circuit board into a plurality of regions and divides the number of inter-region wiring connections into each region. The parts are arranged so that
In the printed circuit board design device configured to display the image on the image display device and output it as a photomask to the photoplotter, the central processing unit may arrange the unplaced components on the printed circuit board. The center of gravity of all unplaced parts is calculated assuming that each of the above unplaced parts is concentratedly placed at the physical center of the area where the unplaced parts should be placed, and the placement of unplaced parts in a certain area is based on that area. The unplaced parts whose center of gravity is offset in the direction of the area adjacent to the area are placed closer to the adjacent area in order of the degree of offset, and the above placed position is taken as the actual placement position of the part and the center of gravity of the remaining unplaced parts. is calculated again, and based on this re-calculated center of gravity, unplaced parts in other areas are placed in the same procedure as above, which is repeated for the placement of all parts. Board design equipment.