JPH0230843Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a power bus structure of a printed circuit board used in various electrical devices, and particularly to a structure that can be used in a small space.

[Conventional technology and its problems]

An equivalent circuit when power is supplied to components or circuits mounted on a printed circuit board or the like is shown in FIG. 4. That is, power is supplied from the power supply E to the component P, and a capacitor C for decoupling is usually added. In such a power supply line, inductance occurs in the wiring pattern and lead wire, inductance Ls occurs between the power supply and the component, and inductance Ll occurs in the lead portion of the capacitor.

The above-mentioned inductance reduces the effect of the decoupling capacitor in the high frequency range, and becomes a big problem in removing high frequency noise. This is due to the influence of the impedance of the power supply line.

Therefore, attempts have been made to widen the width and increase the cross-sectional area of the power supply line in order to lower its impedance. However, in printed circuit boards with limited area, there are restrictions due to the relationship with signal lines, mounted components, etc. be.

[Purpose of invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a low-impedance power bus structure by effectively using a printed circuit board.

[Summary of the idea]

The present invention achieves the above object by utilizing the space between the individual circuit components mounted on the printed circuit board and the printed circuit board to construct a power line in this area. A conductor plate with an insulating layer formed on at least one side is arranged between the individual circuit components and the printed circuit board, and this conductor plate is connected to the printed wiring connected to the power source to form a power supply line. This provides a low impedance power line.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a plan view a and a front view b of an embodiment of the present invention.
This shows an example in which a power supply line is formed under an integrated circuit element. A wiring pattern 11 is formed on the surface of a substrate 10, and a decoupling capacitor 12 and an integrated circuit element 13 are mounted thereon. A conductive plate 14 is mounted below the integrated circuit element 13, and this conductive plate 14 is connected to the wiring pattern 1.
1 and the terminals of the capacitor 12, forming part of the power supply line.

The conductor plate 14 is preferably a metal plate with an insulating layer formed on one or both sides, and its cross section has an insulating layer 22 on one side of the metal layer 21 as shown in FIG.
The metal plate 21 as shown in FIG.
The structure has an insulating layer 22 formed on both sides. The planar shape may be determined based on the wiring pattern on the circuit board and the dimensions and shape of the mounted components. Attachment to the printed circuit board may be performed by soldering or the like.

FIG. 3 shows an example of a printed circuit board used in another embodiment of the present invention, and shows a wiring pattern used when not connected to a capacitor.

[Effect of idea]

According to the present invention, since the inductance in the power supply line can be made small, the impedance in the high frequency region can be lowered, and a power supply bus structure that is effective in removing high frequency noise can be obtained. It is also advantageous in terms of reduced resistance.

In addition, since the conductor plate is placed under the individual circuit components to be mounted, no special space is required for placement, which is advantageous in terms of miniaturization of the device, and does not impose restrictions on the placement of components. There are also advantages.

[Brief explanation of the drawing]

Figure 1 shows an embodiment of the present invention, a is a plan view, b
is a front view, FIG. 2 is a front sectional view showing an example of a conductor plate, FIG. 3 is a plan view of an example of a printed circuit board used in another embodiment of the present invention, and FIG. 4 is a power supply An equivalent circuit diagram of an example of a circuit is shown. 10... Board, 11... Wiring pattern, 12...
...Capacitor, 13...Integrated circuit element, 14...
Metal plate, 21...metal layer, 22...insulating layer.

Claims (1)

[Scope of utility model registration request] In a power bus structure of a printed circuit board on which a wiring pattern is formed and individual circuit components are attached, a conductor plate having at least one side covered with an insulating layer is disposed between the individual circuit components and the printed circuit board. A power supply bus structure for a printed circuit board, characterized in that a power supply path is formed by a power supply path.