JPH01206465A - Method for wiring printed circuit board - Google Patents

Abstract

PURPOSE:To make wiring work more efficient and to shorten design time by carrying out all respective wirings at the interval from a wiring start position to a first connection target position, carrying out all respective wirings at the interval from the first connection target position to a second connection target position and carrying out the wiring between targets. CONSTITUTION:The direction to proceed with the wiring like from the left to the right or the upper to the lower of a printed circuit board is determined. Not one wiring is wired from first to last but distribution in the wiring direction of the pins of electronic parts such as a connector and an IC chip loaded on the printed circuit board is obtained. Next, with a position where the distribution of the pins is high as the target position, the respective wirings at the interval from the wiring start position to the first target position are all carried out. Next, the respective wirings at the interval from the first connection target position to the second connection target position are all carried out and as repeating the connection between the connection target positions successively, the wiring is carried out to the last connection termination point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic wiring method for printed circuit boards such as analog printed circuit boards, digital printed circuit boards, flexible printed circuit boards, and hybrid printed circuit boards.

[Background of the invention and its problems]

As various electronic devices develop and become more sophisticated and multi-functional, the circuit configurations of the various printed circuit boards used in these devices tend to become more complex and multilayered.

In order to cope with this problem, it has been proposed in the past to wire printed circuit boards using wiring methods such as the maze method and the line segment search method. However, none of these methods improves the a distribution ratio and is not used much in practice.

Recently, a wiring device has been commercially available that incorporates a method for rewiring by stripping out stretched wiring and changing the wiring order, but this device has the disadvantage that it takes a long time to wire. .

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic wiring method for a printed circuit board that eliminates the drawbacks of the prior art as described above, improves the efficiency of wiring work, and shortens installation time.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention includes a component placement step of determining the placement position of each electronic component within a wiring area where wiring is performed, and each connection point of the electronic component in one direction of the wiring area. a connection point distribution detection step of detecting a distribution state of (connection pin positions); a target positioning step of determining two or more connection target positions by setting a position with a high distribution of connection points as a target position; and wiring in the wiring area. performing all the wiring for each section from the start position to the first connection target position, then performing all the wiring for each section from the first connection target position to the next second connection target position,
The present invention is characterized by comprising a target wiring process in which wiring between the targets is sequentially performed.

〔Example〕

Next, a printed circuit board wiring method according to an embodiment of the present invention will be explained using one drawing. FIG. 1 is a block diagram for explaining the basic system configuration of an automatic wiring device according to an embodiment, FIG. 2 is a flowchart for explaining the processing operation of the automatic wiring device, and FIG. 3 is an example of a printed circuit board. The circuit diagram, FIG. 4 is a wiring diagram of a printed circuit board formed based on the circuit diagram, and FIG. 5 is a diagram for explaining a specific example of wiring.

First, the overall basic configuration of the CAD/CAM system will be explained using FIG. As shown in the figure, this system is broadly divided into a central processing unit 1, a storage device 2 consisting of a magnetic disk device, an optical disk device, etc. NC tape making device 3, automatic drafting J! &4 and workstations 5a and 5b. In this embodiment, the workstation 5a is permanently installed and the workstation 5b is for expansion.

Specifically, the NC tape creation device 3 includes a keyboard 6
, a printer 7, a paper tape puncher 8, and the like. Further, the workstation 5 specifically includes a system console 9, a color graphic display 10, a digitizer 11, and a command key 12.
It is composed of etc. The connection relationship of each device is as shown in the figure. Next, the processing flow of the digital circuit CAD system will be explained using FIG. 2. First, step (hereinafter, S
It is abbreviated as )l, the entire logic circuit diagram to be designed is created. Next, in order to divide and realize this logic circuit on a plurality of printed circuit boards, logical division is performed in S2, and based on this, a partial logic circuit diagram is created for each printed circuit board in S3.

Next, at 84, if the logic circuits are described at the gate level, gate assignment is performed to assign them to corresponding IC chips. Thereafter, in S5, the IC chip (package) to which the gate has been assigned is placed and fixed on the printed circuit board. Since this component placement greatly affects the ease of later wiring design, interactive layout design is performed using a graphic display.

At the gate allocation stage described above, the relative positional relationship of the IC chips (packages) has not been determined, so the allocation of gates within the component has not been determined. After 86 component placements are completed, gate positions within each IC chip (package) are determined and pin assignments within the IC chip (package) are performed (S6).

Next, in 87, wiring design is performed. Since the detailed operation will be explained later, the explanation of the wiring operation will be omitted here. As far as designing by automatic wiring is concerned, there are almost no wiring mistakes, but when wiring is corrected using a graphic display after automatic wiring, there is a possibility that mistakes may be made because it is done manually. For this reason, in S8, for example, inspection for short circuits and open failures between wirings, and checking the spacing between patterns are performed. Finally, in step 89, artwork data is created, logical information is extracted from it,
This is compared with the input logic information.

Next, a specific example of the wiring method will be described.

FIG. 3 is an example of a circuit diagram of the printer 1-board to which wiring is to be performed. In this figure, CN1 and CN2 are connectors, ICI, IC2, and ANDI are IC chips, and small Arabic numerals placed around each electronic component indicate the bin number of each element.

Based on the circuit diagram drawn on this paper, create the following wiring information.

r CN1 (+)=IC1(1)CNI (2
) = IC2 (2) CNI (3) = AND1 (2) ICI (1
1) = IC2 (1) ICI (10) = AND1 (1) ANDI
(3) = IC2 (3) I C2 (11) = CN2 (1) J The wiring information obtained in this way is input to an automatic wiring device for printed circuit boards, and this wiring device uses the wiring information to calculate - Wiring using more than one wiring layer. Note that wiring between layers is connected using through holes to avoid short circuits. Based on the above-mentioned wiring information, a wiring diagram as shown in FIG. 4 is created. The O marks in the figure indicate the pin positions of each element, the * marks the through-hole positions, and the solid lines the front wiring.

The dotted lines indicate the back side wiring, CN1, IC1, etc. indicate the names of the electronic components to be placed, and the rectangular portions indicate the positions of the electronic components. This wiring diagram is drawn on a photosensitive film in actual size or variable magnification to obtain a visualized wiring diagram of the printed circuit board.

When creating a wiring diagram based on the above-mentioned wiring information, the direction in which the wiring is to be advanced is determined, such as from the left to the right of the printer 1 board, or from the top to the bottom. Instead of wiring a single wire from start to finish as in the past, for example, connectors and
The distribution of pins (connection points) of electronic components such as C chips (the placement positions of the electronic components have already been determined) in the wiring direction is taken. Next, all wiring in the section from the wiring start position to the first target position is performed, with the position where the distribution of pins (connection points) is high as the target position. Next, all the wiring is done for each section from the first connection target position to the next second connection target position, and the wiring is made until the final connection end point by sequentially repeating the connection between the connection target 1 and the position.

Note that, for example, if there is no pin to be connected at the second connection target position and there is a pin at the next third connection target position, a temporary target is provided at the second connection target position, and the first connection target ~ to the temporary target, and in the next step, connect the temporary target to the third connection target. Of course, if there is a pin (target) to be connected before the connection target position that we are aiming for this time, we will wire up to that point.

After wiring to a predetermined target position, including the above-mentioned temporary target 1-, if it is possible to wire electronic components such as IC chips in the opposite direction to the direction in which they have already been wired, it is better to shift them. This is particularly effective when two wires are wired between 0.1 inches, so-called two-wire logic between pins, but it can also be applied when one or three or more wires are wired between 0.1 inches. Of course, if the printed circuit board has sufficient size, it is not necessary to put them together.

Next, a specific example of two logic wiring lines between pins will be explained using FIG.

One pin A of a normal IC chip has four logic grids 4
It consists of 5 ports, C, and 2. When wiring from pin A at the target position to the pin at the next (n+1)th target position, if the wiring direction is set in advance Enter the lower left part 2 of the logic grid in B (wire ■).

For wiring that passes through the section between the n-th target position and the (n+1)-th target position, a temporary target C is set at the n-th target position, and a temporary target C is set at the (n+1)-th target position. l
-D and wire between these temporary targets C and D (
Wiring ■).

In this way, when wiring from one temporary target to the next temporary target, it is possible to have a directionality such as whether to maintain the same Y coordinate, or to go up as a whole, or to go down on the contrary.

When the wiring is completed to the (n+1)th target position, the pin at the (n+1)th target position is
Attach as much as possible to the opposite side of the wiring direction X. Of course, if the pins of the electronic components at the n-th target position and the (n+1)-th target position are bent to the same component, they cannot be brought together. At that time, when the pin of the electronic component at the nth target position is moved to the opposite side to the wiring direction, at the same time, the pin of the electronic component at the (n+1)th target position is also moved by the same dimension to the opposite side to the wiring direction. I'll leave it to you.

In the initial arrangement of electronic components, it is sufficient to spread them out loosely and place them in their approximate positions.

Through-holes also allow the use of smaller microvias than conventional ones.

[Effects of the Invention] Since the present invention has the above-described configuration, there is no need to redo the wiring, so wiring can be completed quickly and completely, and the wiring work can be made more efficient and the time required for several sets can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining the basic system configuration of an automatic wiring device according to an embodiment of the present invention, FIG. 2 is a flowchart for explaining the processing operation of the automatic wiring device, and FIG. 3 is an example. A circuit diagram of the printed circuit board, FIG. 4 is a wiring diagram of the Print 1 board formed based on the circuit diagram,
FIG. 5 is an explanatory diagram for explaining a specific example of wiring. A-B...Pin, C, D...Temporary target, A, Mouth, Ha, 2...Logic lattice, ■, ■・
...Wiring, X...Wiring direction. Figure 3 Figure 4 ND1

Claims (1)

[Claims] (1) A component placement process that determines the placement position of each electronic component within the wiring area where wiring is performed, and connection point distribution detection that detects the distribution state of each connection point of the electronic component in one direction of the wiring area. a target positioning step in which two or more connection target positions are determined by setting a position where the distribution of connection points is high as a target position; and each wiring in the section from the wiring start position to the first connection target position in the wiring area. A method for wiring a printed circuit board, comprising the steps of: performing all of the following steps, and then performing all wiring for each section from the first connection target position to the next second connection target position.