JPH04179183A - Wiring board - Google Patents

Abstract

PURPOSE:To enable a noise voltage emitted from a wiring pattern to be estimated at the layout design phase of a printed board by providing a printed-circuit board with a wiring pattern and a signal input/output circuit that serve to quantitatively measure noise voltage induced by reflections, cross talks, EMI, or the like. CONSTITUTION:In an experimental wiring board 1, the waveforms of the reflected waves of input signals are observed by wirings 20-23 different in width, whereby the characteristic impedance and the propagation constant of the wirings 20-23 can be obtained. In a cross talk experiment, a connection pin 62 of one of parallel wires of a conductor pattern is connected to a connection pin 61 which serves as an input terminal of the applied signal or an output terminal connection pin 70 of an IC, whereby pulse signals are inputted to the conductor pattern. An input/output terminal 63 of the other of the parallel wires of the conductor pattern and the other end of the conductor pattern are connected to connection parts 60-70, whereby the various terminated states can be selected. As mentioned above, in a cross talk measuring experiment, measurements can be executed changing the conductor patterns in terminal load conditions. Basing on these measurement data and a theory, a relation between a physical structure size, electrical characteristics and a cross talk voltage can be analyzed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is based on experiments and experiments on electromagnetic characteristics and phenomena on wiring boards.
The present invention relates to an experimental device for measuring, and in particular, to an experimental wiring board and an experimental device for measuring reflection, crosstalk, EM, and I.

[Conventional technology]

Generally, in high-speed pulse transmission boards, as the clock frequency increases, the generation of noise such as tarost distortion, reflection, and EMI has become a problem. Regarding the noise generated on these wiring boards, after laying out each circuit, we actually create a board for Print 1 and quantitatively measure what kind of noise is generated on the circuit wiring. and took measures. As described in Japanese Unexamined Patent Publication No. 1-28885, the electrical characteristics of a conductor pattern on a circuit board have been evaluated by preparing a wiring board and measuring various characteristics of the conductor pattern. In other words, the quantitative value of noise generated for each circuit board could not be determined unless the board was actually created. As a result, the development process was prolonged.

[Problem to be solved by the invention]

However, if it is impossible to know the noise generated unless you create a board and measure noise for each layout pattern of each circuit board, as in the past, you have to create a board and measure noise every time you change the layout pattern. Noise countermeasures cannot be taken. This led to a prolonged development process.

The purpose of the present invention is to solve this problem, and to provide a mounting experiment board and an apparatus for making it possible to predict the noise voltage generated from the wiring pattern at the stage of layout design of the printed circuit board 1 to the board. Our goal is to provide the following.

[Means to solve the problem]

To achieve this objective, the wiring board of the present invention is designed to measure line width, parallel line length, distance between parallel lines, serial wiring, etc. The configuration is such that a wiring pattern is provided to allow implementation experiments using branch length and radial wiring length as parameters.

Electromagnetic analysis of the experimental data obtained from these experiments makes it possible to predict noise generation from the physical layout and electrical characteristics of wiring patterns. As a result, noise countermeasures can be taken from the board design stage, and the board development process can be shortened.

[Effect]

With this configuration, crosstalk and reflected waveforms can be measured under various measurement conditions, and characteristic impedance and propagation speed, which are fundamental constants of the line, can also be determined.

By observing the waveforms at each point of the drive line that applies pulses and the sense line where crosstalk voltage is induced in parallel wiring, we can calculate the relationship between voltage, drive human power pulse, and physical configuration size. A response is required.

Further, the reflection coefficient and characteristic impedance are determined from the relationship between the input waveform and the reflected waveform.

The correspondence between these experimental data and theory makes it possible to quantitatively predict induced noise from the physical configuration size and electrical characteristics of wiring patterns.

Therefore, it is possible to design the board so that the noise is below the level that would cause malfunctions at the board design stage.

〔Example〕

Examples of the present invention will be described in detail below.

First, FIG. 1 shows a layout diagram of a mounting experiment board according to a first embodiment of the present invention. 1- in FIG. 1 is a four-layer wiring board, and 11-]4 are parallel wiring intervals of 0.1 and 0.1, respectively.
5, 0.2, 0.3mm parallel wiring, 1-5
-17 have the same wiring spacing and the parallel wire length is 1. O
, J-5, 20, and 25 cm parallel wiring conductor patterns. 30 to 32 are radial wires that are wired radially from the input end to a plurality of output ends, and each wire has a different length.

・4・ 41 to 43 are conductor patterns of serial wiring in which a plurality of loads are connected to one wiring, each having a different branch length, and can be connected to the input/output section 51. 50,5]
, is an input/output section between the conductive pattern and the measuring device. Second
The figure shows details of the input/output section 50. Reference numeral 60 in FIG. 2 is a connector for connecting an applied signal from a signal generator such as a pulse generator, and 61 is a connection pin drawn out from the connector 60. 62 and 63 are signal connection pins of parallel wiring conductor patterns. 64 to 70 are signal connection parts drawn out from the connection terminals of the 1-4 pin DIP socket. These connecting pins 6] to 70 are connected directly to the parallel wiring conductor pattern.

It is also possible to connect the applied signal 6o, 14 pin D
IP (7) IC device (INVERTER.

It is also possible to connect the input and output terminals of N A and N D . Further, the connecting pin 71 is connected to the ground, and by connecting the parallel wiring conductor pattern 63 to the connecting pin 71, it can be terminated to the ground.

Next, an experimental method using this experimental wiring board will be explained. By observing the reflected waveform of the input signal on the wiring lines 2o to 23 having different wiring widths in FIG. 1, the characteristic impedance and propagation constant at each FA width can be determined. In the cross 1-1 experiment, connect the connecting pin 62 of the conductor pattern on one side of the parallel lines in FIG. A pulse signal is applied to the conductor pattern. Moreover, various termination states can be selected by connecting the input/output section 63 of the other parallel wiring conductor pattern and the other end of the conductor pattern to the connection sections 60 to 76. For example, matching termination can be achieved by connecting connection pins 63 and 71 with a resistor with the same value as the characteristic impedance of the g path, and
By connecting to the input end connection pin 69 of , an input end connection state can be realized. In this manner, crosstalk measurement experiments can be performed by changing the load conditions at the ends of each conductor pattern of the drive line and sense line. Using these measurement data and theory, it is possible to analyze the relationship between physical component size, electrical properties, and Talostok voltage. Further, by using the radial wiring patterns 30 to 32 and the serial wiring patterns 41 to 43, it is possible to verify by experiment the characteristics of multiple reflection due to differences in the wiring patterns. Through these experiments and analyses, it is possible to predict reflection and crosstalk voltage from the physical size and electrical characteristics at the board design stage.

Next, a second embodiment of the present invention will be described using FIG. In the second embodiment, surface-mounted components are mounted on a board similar to the first embodiment. Figure 3 shows
It is a diagram showing details of an input/output unit 5o of the first embodiment.

60a in FIG. 3 is a connector for connecting an applied signal from a signal generator such as a pulse generator, and 61-a is a connecting pin drawn out from the connector 60a. 62a, 63a
are signal connection pins with parallel wiring conductor patterns.

64a to 70a are signal connection portions drawn out from the connection terminals of the 14-pin SOP. As in the first embodiment, these connecting pins 61. It is also possible to connect the applied signal 60a directly to the flat, 7, and row wiring conductor patterns by joining a to 70a, and it is possible to connect the applied signal 60a directly to the flat, 7, and row wiring conductor patterns, and it is possible to connect the applied signal 60a directly to the 14-pin SOP IC device (
It is also possible to connect the input and output terminals of TNVERTER, NA, ND). Further, the connecting pin 71a is connected to the ground, and can be terminated to the ground by connecting the parallel wiring conductor pattern 63,1 to the connecting pin 71a. As a result, even when surface-mounted components are mounted, experiments can be conducted in the same manner as in the first embodiment, and similar effects can be obtained.

Next, a third embodiment of the present invention will be described using FIG. 4. The third embodiment is a mounting experiment apparatus including the mounting experiment board described in the first and second embodiments. Figure 4 is a configuration diagram of this implementation experiment equipment, where 80 is a personal computer (hereinafter referred to as PC), 81 is a pulse generator (hereinafter referred to as PG) that generates an input signal (connected to the PC with an E P-I B cable, etc.). The signal output is connected to an experimental board. 82 is an experimental board, and this experimental board 82 can be connected to an expansion slot of a PC with a connector 83.
・ It has become a thing. By controlling the PG81 with the PC80, the rise time, peak voltage, etc. of the input waveform can be changed, and the output waveform measured using the same experimental circuit as the board of the first embodiment is converted into an analog signal using the A/D converter 84. It is possible to convert the data into digital data, import the data into the PC 80, and perform data processing. In this way, by automatically performing measurement and data processing on a PC, the efficiency of measurement work is increased and the same effects as in the first and second embodiments can be obtained.

〔Effect of the invention〕

In the present invention, it is possible to know how crosstalk, reflection, and propagation speed on a wiring board depend on the configuration and layout of the board, so it is possible to predict noise that will occur at the stage of designing a wiring board. At this stage, noise countermeasures can be taken. Therefore, compared to the case where noise countermeasures are taken only after creating a prototype board, the number of man-hours required for developing a wiring board can be shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a mounting experiment board according to the first embodiment of the present invention, FIG. 2 is an explanatory diagram of the input/output section of FIG. 1, and FIG. Explanatory diagram corresponding to the human output section, No. 4
The figure is an explanatory diagram of a mounting experiment apparatus including the mounting experiment board of FIG. 1. 1... Mounting experiment board, 11-7] Parallel wiring pattern, 30-32... Radial wiring pattern, 41-43...
- Serial wiring pattern, 80...Personal computer, 81...Pulse generator. 84...A/D converter.・１１・

Claims (6)

[Claims] 1. A wiring board comprising a wiring pattern and a signal input/output section that can quantitatively measure induced noise voltages such as reflection, crosstalk, and EMI in wiring on a printed circuit board. 2. A mounting experiment measuring device comprising the wiring board according to claim 1 and a measuring device for measuring the wiring board. 3. In claim 1, the wiring interval is 0.1 mm to 0.3 mm.
Parallel wiring changed in the range of mm and line width of 0.1 mm
A wiring board with wiring patterns of a single wiring group varied within a range of ~0.3 mm, serial wiring, and radial wiring. 4. The wiring board according to claim 1, having means for switching an input terminal and an output terminal of an experimental IC. 5. In claim 2, the interval is 0.1 mm to 0.3 mm.
Parallel wiring with a range of 0.1mm to 0.
．． A mounting experiment measurement device that has a wiring board with individual wiring patterns, serial wiring, and radial wiring that are varied within a range of 3 mm. 6. 3. The mounting experiment measuring device according to claim 2, further comprising means for switching an input terminal and an output terminal of the experimental IC.