JPH03212769A - Balanced transmission wiring checking system - Google Patents

Abstract

PURPOSE:To automatically check a necessary condition and to improve the productivity and quality of printed substrates by detecting whether a required condition between a pair of wirings based upon balanced transmission wiring information extracted from substrate connection information is satisfied or not. CONSTITUTION:When the connection information of a CAD-designed substrate is inputted from an information file 1 through an input part 2 and a processing part 3, balanced wiring information is extracted by an extracting part 51 in a checking mechanism 5 and an inter-wiring existence checking part 52, a recording length checking part 53 and an inter-record distance checking part 54 respectively check whether another signal line exists between wirings or not, whether the wiring lengths of a pair of wirings are mutually equal or not and whether a wiring length distance is less than a prescribed length or not. Thus, the productivity, quality, etc., of the printed substrate can be improved by the automatic checking system.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a balanced transmission wiring check system, and more particularly to a balanced transmission wiring check system in a printed circuit board CAD system for designing wiring on a printed circuit board using CAD technology.

BACKGROUND OF THE INVENTION In addition to general signal lines, power supply lines, ground lines, etc., there are balanced transmission lines as types of printed wiring on printed circuit boards.

This balanced transmission wiring is a wiring between elements used in a signal transmission form extending between printed circuit boards.

For example, if a connection is required between the input/output terminals of a circuit component on one printed circuit board and the input/output terminals of a circuit component on another printed circuit board, the input/output terminals (input/output pins) of these circuit components are required. ) and the input/output connector bin of the printed circuit board on which it is mounted, balanced transmission wiring may be used.

A CAD system for a printed circuit board using such balanced transmission wiring is not provided with a check function for checking whether the balanced transmission wiring is correctly wired. Therefore, the wiring results are manually inspected to check whether they are correct or not.

In this way, conventional printed circuit board CAD systems rely on manual checking of balanced transmission wiring, which requires a large amount of man-hours and is impossible to guarantee 100% quality. The disadvantage is that it cannot be expected to improve performance or quality.

OBJECT OF THE INVENTION The present invention has been made in order to eliminate the drawbacks of the prior art, and its purpose is to automatically establish the conditions necessary for balanced transmission wiring, so that printed circuit boards can be An object of the present invention is to provide a balanced transmission wiring check system for printed circuit boards, which is designed to improve productivity and quality.

Structure of the Invention The balanced transmission wiring check system according to the present invention includes a means for extracting balanced transmission wiring information from connection information on a circuit board, and a means for extracting balanced transmission wiring information from the extracted balanced transmission wiring information. means for detecting the presence or absence of a signal line; means for detecting whether the lengths of the pair of wires are equal from the extracted balanced transmission wiring information; and the distance between the pair of wires from the extracted balanced transmission wiring information. The present invention is characterized in that it includes means for detecting whether or not is maintained within a predetermined constant value.

Example Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a system block diagram of an embodiment of the present invention.

The net information file 1 is a file in which circuit connection wiring information on a printed circuit board designed by CAD technology is stored in advance. The human power section 2 reads the net information from this file 1, and the processing section 3 sends this net information to the balanced transmission wiring check verification mechanism 5, and instructs the check verification mechanism 5 to check the balanced transmission wiring. It instructs the verification results to be performed and also controls how the verification results are derived to the output section 4.

The check verification mechanism 5 includes an extraction unit 51 that selectively extracts only the balanced transmission wiring information to be verified from the network information, and an extraction unit 51 that selectively extracts only the balanced transmission wiring information to be verified from the network information, and a check verification mechanism 5 that detects the presence or absence of other signal lines between a pair of wirings constituting the extracted balanced transmission wiring. Wiring presence/absence checking section 5
2, a wire length check section 53 that checks whether the lengths of this pair of wires are equal to each other, and a wire length check section 53 that checks whether the distance between this pair of wires is maintained within a predetermined constant value. and an inter-wiring distance check section 54.

The above three conditions are required for balanced transmission wiring, and are determined in consideration of crosstalk (noise) and the like. In the past, these three conditions were checked by human visual confirmation, but in the present invention, the system configuration shown in FIG. These three conditions are automatically checked and verified.

Here, the operation of the embodiment of the present invention will be explained using a circuit example as shown in FIG. In FIG. 3, circuit component 11
It is necessary to connect the input/output terminals AO, BO, and AlB1 to other circuit elements (both not shown) on other printed circuit boards, and this connection is made by balanced transmission wirings 10A, IOB, and 12A, 12B. This shows the case where still,
A to D indicate connector bins of a printed circuit board on which this circuit component 11 is mounted.

These balanced transmission wirings are given net names in advance to identify them, and the wirings 10A and 10B are given net names such as aaa+ and aaa-, respectively, and the wirings 12A and 12B are given net names such as aaa+ and aaa-, respectively. For example bbb+, bb
It is assumed that a net name b- is given to each net name. The last digits of this net name, + and -, are codes for recognizing a pair of signals of the balanced transmission line, and + and - are not used for nets other than the signals of the balanced transmission line.

Therefore, the extraction unit 51 extracts the balanced transmission wiring from the net information using this net name (step 51). As shown in (A),
Check whether other signal lines 12 exist (step 52).

To check the presence or absence of this signal line, since each wiring information in the net information is given in two-dimensional coordinates of the A method of detecting the presence or absence of the signal line 12 is used.

Next, the check section 53 checks the extracted balanced transmission wiring 10A,
Regarding IOB, the lengths of these pair of wires LA, LB
A check is made to see if they are equal (step 53). This wiring length is determined by calculating each length LASLB using the coordinate values as shown in FIG. 4(B), and comparing these calculated lengths.

After that, the check section 54 checks this extracted balanced transmission wiring]
, OA, and IOB, it is checked whether the distance between the pair of wires is maintained at a predetermined value or less as shown in FIG. 4(C) (step 54).

This distance between wires can also be calculated using coordinate values, and the distance is calculated over the entire section and compared with a constant value.

This constant value is set to one grid pitch (2.54 mm) of the printed circuit board, as shown in FIG. 4(C).

If all of the above three check results are OK, a display to that effect is made on the output unit 4, and if even one is NG, a display to the effect that it is NG is made on the output unit 4 (steps 55 to 4). 58).

The above processing is performed for all balanced transmission lines in the net information 1. .

Effects of the Invention As shown above, according to the present invention, by constructing a CAD system to check the balanced transmission wiring on the printed circuit board, all checks can be automatically performed faster and more reliably, resulting in 100% accuracy. This has the effect of making checking possible, improving quality and reducing man-hours.

[Brief explanation of drawings]

Fig. 1 is a system block diagram of an embodiment of the present invention, Fig. 2 is a flowchart showing the operation of the embodiment of the invention, Fig. 3 is a circuit diagram showing an example of balanced transmission wiring, and Figs. (C)
2A and 2B are diagrams showing check conditions for balanced transmission wiring, respectively. Explanation of symbols of main parts 1...Net information 51...Balanced transmission wiring extraction section 52...Wiring presence/absence check section 53...
・Wire length check section

Claims (1)

[Claims] (1) A means for extracting balanced transmission wiring information from connection information on a circuit board, and detecting from this extracted balanced transmission wiring information the presence or absence of another signal line between a pair of wirings constituting this balanced transmission wiring. means for detecting whether the lengths of the pair of wires are equal from the extracted balanced transmission wiring information; and means for detecting whether the lengths of the pair of wires are equal from the extracted balanced transmission wiring information; A balanced transmission wiring check system, comprising means for detecting whether or not the balanced transmission wiring is maintained.