JPH11312890A - Printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed wiring board which is capable of shielding and separating from each other front and rear circuits attached to the printed board at a relatively low cost. SOLUTION: A signal processing section 2 and a shield case 3 which shields the section 2 are arranged on the front surface of a main board 1. The whole surface of the first layer 4 of the main board 1 is composed of a grounding conductor, and the layer 4 has a front and rear surface shielding functions and imparts reinforcing effect on the shield case 3. A digital control section 8 is arranged on the rear surface side of the substrate 1, and the circuit of the control section 8 is constituted by using an interstitial via hole between a third layer 6 and fourth layer 7 of the board 1, so as to prevent the circuit of the control section 8 from being exposed to the first layer 4 used as the grounding conductor for the board 1. The third layer 5 of the substrate 1 is constituted in a power source section or grounding conductor so as to reinforce the shielding effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board having a basic structure when housed in a housing in various types of units used in electronic equipment such as a personal computer, and more particularly to a printed wiring board mounted on a printed board at a relatively low cost. It is configured to enable the shielding separation of the front and back circuits to be performed.

[0002]

2. Description of the Related Art With the spread of personal computers and the unitized structure of electronic devices, the structure in which functions are incorporated in electronic devices by mounting them on printed circuit boards is expanding. Accordingly, it has become necessary to coexist a digital control unit and a signal processing unit including an analog circuit on a printed circuit board. Therefore,
An electromagnetic shield wiring board having a structure in which a shield layer is provided on a printed board itself has been proposed. That is,
As shown in FIG. 5, the conductive support 15 is a wiring conductor.
It is configured to have a shielding effect by being sandwiched by 14.

[0003]

However, providing a shield layer in a printed circuit board requires a request from a specific board maker, which increases the manufacturing cost of the device. Further, it is necessary to enhance the shielding effect of the shielding case arranged on the printed circuit board.

[0004] In order to solve such problems, an object of the present invention is to provide a printed circuit board configured to realize shielding separation of a front and back circuit attached to a printed circuit board at a relatively low cost.

[0005]

In order to achieve the above object, a first aspect of the present invention is to use a first layer of a multilayer main substrate as a ground conductor and to use an interstitial via hole to form a structure on a back surface. By shielding and separating the front and back surfaces of the printed circuit board without exposing the circuit on the front surface, and connecting the shield case and the ground conductor on the front surface, the shield effect of the shield case is synergized. .

According to a second aspect of the present invention, a circuit formed on a front surface of a printed circuit board is formed on a rear surface by using one intermediate layer of a multilayer main substrate as a ground conductor and using an interstitial via hole. The circuit is configured such that the front and back surfaces are shielded and separated without exposing, and similarly, the circuit formed on the back surface is not exposed on the front surface.

[0007]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, the first and second layers of a multilayer main board are used as ground conductors and interstitial via holes are used, so that the front and rear faces of a printed board are used. The printed circuit board is characterized in that the shielding effect is shielded and separated, and the shielding effect of the shielding case is synergized by connecting the shield case and the ground conductor on the component surface. And the rear surface are shielded and separated, and the shield case on the component surface is connected to the ground conductor, so that the shield effect of the shield case can be synergized.

According to a second aspect of the present invention, an intermediate layer of a multilayer main substrate is used as a ground conductor and an interstitial via hole is used.
This is a printed wiring board characterized in that the front surface and the back surface of the printed circuit board are configured to be shielded and separated, and has an effect that the front surface and the back surface of the printed circuit board can be shielded and separated.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a side view which shows the basic structure of the printed wiring board of embodiment. In FIG. 1, a first main board 1 constituting a printed wiring board 11 constitutes a main circuit component and is printed and wired. This main board 1
Uses an interstitial via hole having a four-layer structure. On the front side of the main board 1, a signal processing unit 2 that is printed and wired to form a second board, and a shield case 3 that shields the signal processing unit 2 are attached.

The entire surface of the first layer 4 of the main substrate 1 is a ground conductor, and is connected to the shield case 3. On the second layer 5 of the main board 1, the power supply and the ground conductor of the signal processing section 2 are arranged, and the first layer 4 of the main board 1 is provided.
Assist the earth conductor.

A digital controller 8 is mounted on the back side of the main board 1. The third layer 6 of the main board is mainly used for signal patterns of the digital controller 8, and the fourth layer 7 of the main board 1 is It is used for the ground conductor of the digital control unit 8 and the signal pattern of the digital control unit 8 that is insufficient on the third layer 6 of the main board 1.

FIG. 2 shows a structure of an interstitial via hole of the main board 1 according to the first embodiment of the present invention. The circuit pattern is connected to the second layer 5 by a blind via hole 9 between the first and second layers from among the interstitial via holes.

The fourth layer 7 on the back surface of the main substrate 1 and the third
The circuit pattern is also connected to the layer 6 by a blind via hole 10 between the third and fourth layers from among the interstitial via holes. As a result, the signal pattern of the digital control unit 8 which is not required in the signal processing unit 2 is not exposed on the front side.

As described above, according to the first embodiment of the present invention, the signal processing unit 2 disposed on the front side and the digital control unit 8 disposed on the back side are completely shielded and separated, and Processing part 2 is composed of shield case 3 and main board 1
And the first layer 4 can completely shield.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
FIG. 3 is a side view illustrating a basic configuration of the printed wiring board according to the embodiment. In FIG. 3, a first main blank 1 constituting a printed wiring board 11 constitutes a main circuit component and is printed and wired. This main board 1
Uses an interstitial via hole having a six-layer structure. On the front side of the main board 1, a signal processing unit 2 that is printed and wired to form a second board, and a shield case 3 that shields the signal processing unit 2 are attached.

The entire surface of the third layer 6 or the fourth layer 7 which is an intermediate layer of the main substrate 1 is a ground conductor,
Connected to shield case 3. 1st of main board 1
On the layer 4 and the second layer 5, a signal pattern of the signal processing unit 2, a power supply and a ground conductor are arranged.

On the back side of the main board 1, a digital controller 8 is arranged. The fifth layer 12 of the main board is mainly used for signal patterns of the digital controller 8, and the sixth layer 13 of the main board 1 is It is used for a signal pattern of the digital control unit 8 which is insufficient in the ground conductor of the digital control unit 8 and the fifth layer 12 of the main board.

FIG. 4 shows a structure of an interstitial via hole of a main board 1 according to a second embodiment of the present invention. The circuit pattern is connected to the second layer 5 by a blind via hole 9 between the first and second layers from among the interstitial via holes.

The circuit patterns are also connected between the fifth layer 12 and the sixth layer 13 on the back surface through the blind via holes 10 between the fifth and sixth layers from among the interstitial via holes. The remaining third layer 6 and fourth layer 7 are all ground conductors.

As a result, the signal pattern of the digital control unit 8 which is not required in the signal processing unit 2 is not exposed on the front side, and the signal pattern of the signal processing unit 2 on the front side is exposed on the back side. Disappears.

As described above, according to the second embodiment of the present invention, the signal processing unit 2 disposed on the front side and the digital control unit 8 disposed on the rear side are completely shielded and separated. Processing part 2 is composed of shield case 3 and main board 1
Can be completely shielded by the third layer 6 and the fourth layer 7.

[0023]

As is apparent from the above description, according to the present invention, the front and back surfaces of the printed circuit board can be shielded and separated, and the shield case on the component side and the ground conductor can be used for the shield case. This has the effect that a structure for synergizing the shielding effect can be realized at a relatively low cost.

[Brief description of the drawings]

FIG. 1 is a side view showing a basic configuration of a printed wiring board according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a structure of an interstitial via hole of a main substrate 1 according to the first embodiment of the present invention;

FIG. 3 is a side view showing a basic configuration of a printed wiring board according to a second embodiment of the present invention;

FIG. 4 is a main board 1 according to a second embodiment of the present invention.
Diagram showing the structure of the interstitial via hole of

FIG. 5 is a view showing a cross section of a conventional electromagnetic wave shielding wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main board 2 Signal processing part 3 Shield case 4 Multilayer board 1st layer 5 Multilayer board 2nd layer 6 Multilayer board 3rd layer 7 Multilayer board 4th layer 8 Digital control part 9 Blind via hole 10 Blind via hole 11 Printed wiring board 12 Fifth layer of multilayer board 13 Sixth layer of multilayer board 14 Wiring conductor 15 Conductive support

Claims (2)

[Claims] The present invention uses a first layer of a multilayer main board as a ground conductor and uses an interstitial via hole to shield and separate the front and back surfaces of a printed circuit board, thereby providing a shield case and a ground conductor for a component surface. A printed wiring board characterized in that the shield effect of the shield case is synergized by connecting the printed circuit board to the printed circuit board. 2. The printed circuit board according to claim 1, wherein a middle layer of the multilayer main board is used as a ground conductor and an interstitial via hole is used to shield and separate the front and rear faces of the printed board. Printed wiring board.