JPH11112115A - Mounting method for parts of printed wiring board and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a shielding effect for radiation noise and external noise. SOLUTION: A printed wiring board 1 having the structure, which is bent with electronic parts 2 being provided in the inside and wherein the electronic parts 2, a conducting pattern and the like are surrounded by a grounding layer, is constituted. The grounding layer is connected to a ground potential. Therefore, when the circuit which is constituted in this printed wiring board 1 is operated, the radiation noise generated from the electronic part 2, the conducting pattern and the like, and the external noise, are shielded by the grounding layer, and the malfunction of that circuit is decreased. At the same time, the malfunction of external electronic devices are decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting components on a printed wiring board with an improved shielding effect against radiation noise, external noise, and the like, and an electronic device incorporating the printed wiring board.

[0002]

2. Description of the Related Art Conventionally, as a countermeasure against radiated noise generated from an electronic device and a malfunction caused by external noise flying to the electronic device, a housing of the electronic device is made of metal, or the housing is made of a conductive material. Enhancement of shielding has been performed by enclosing with a substance (for example, applying conductive plating, vapor deposition, painting, etc.). In particular, in the case of a printed wiring board which is a source of radiation noise, a method of applying a conductive paste to the surface to enhance the shielding of the printed wiring board itself, or a method of applying EMI (Electro -M
magnetic Interference) filter, ferrite beads,
Methods using noise suppression components such as inductors and feedthrough capacitors have been used.

[0003]

However, the conventional method of strengthening the shielding of a printed wiring board and the method of using noise suppression components have a problem that the price of the printed wiring board increases. In addition, in the method of applying a conductive paste to the surface of a printed wiring board, the conductive paste cannot be applied to electronic components mounted on the printed wiring board, so that a sufficient shielding effect cannot be obtained. was there.

[0004]

According to a first aspect of the present invention, there is provided a method for mounting a component on a printed wiring board, comprising: a ground layer forming a bottom surface; A flexible printed wiring board having an insulating layer and a pattern layer on which conductive patterns are alternately stacked, and on which electronic components are mounted, is used. The ground layer is composed entirely of a conductive solid layer, the uppermost surface of the printed wiring board is composed of the pattern layer, the electronic component is mounted on the pattern layer, and the electronic component is bent inside. The solid layer surrounds the electronic component and connects the solid layer to a ground potential. According to the first aspect, since the component mounting method of the printed wiring board is configured as described above, the electronic component and the conductive pattern are surrounded by the ground layer after the electronic component is bent inside. Is completed. This ground layer is connected to a ground potential.

According to a second aspect of the present invention, in a method for mounting components on a printed wiring board, a ground layer constituting a bottom surface and a pattern layer having an insulating layer and a conductive pattern alternately laminated on the ground layer are provided. Then, flexible first and second printed wiring boards on which electronic components are mounted are used. Each of the ground layers is entirely formed of a conductive solid layer, the uppermost surface of each of the printed wiring boards is formed of the pattern layer, and the electronic component is mounted on each of the pattern layers. Bend each with the inside,
The electronic components are surrounded by connecting the ends of the solid layers to each other, and the solid layers are connected to the ground potential. According to the second aspect, after each electronic component is bent inside, a printed wiring board having a structure in which each electronic component and each conductive pattern are surrounded by each ground layer is completed. This ground layer is connected to a ground potential.

In the third invention, the solid layers of the first and second inventions are arranged such that opposing ends of a void surrounded by the wiring board are connected via a plurality of conductive metals. . Each of these conductive metals is provided at an interval of less than 1/4 of the wavelength of noise that needs to be shielded. According to the third aspect, the opposing ends of the gap surrounded by the own wiring board are connected via the plurality of conductive metals, so that a reduction in the shielding effect due to the presence of the gap is prevented. You. In this case, it is shielded against noise whose wavelength is four times or more the distance between these conductive metals.

According to a fourth aspect of the present invention, there is provided an electronic apparatus having a housing formed by combining first and second housing pieces and an electronic component built in the housing.
It is configured as follows. Flexible first and second printed wiring boards having a ground layer constituting a bottom surface and a pattern layer on which insulating layers and conductive patterns are alternately laminated on the ground layer, and on which electronic components are mounted. It has. Each of the ground layers is entirely formed of a conductive solid layer, the uppermost surface of each of the printed wiring boards is formed of the pattern layer, and the electronic component is mounted on each of the pattern layers. The printed wiring boards are attached along the inner surfaces of the housing pieces, respectively, and the solid layers are connected to each other and connected to the ground potential when the housing pieces are combined. Like that. According to the fourth aspect, since the electronic apparatus is configured as described above, the entire circuit of the first and second printed wiring boards is wrapped in the ground layer. Therefore, when the circuits formed in these printed wiring boards are operating, radiation noise and external noise generated from each electronic component and each conductive pattern are shielded by the ground layer, and the malfunction of the circuits is reduced. In addition, malfunctions of external electronic devices are reduced. Therefore, the above problem can be solved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a perspective view of a printed wiring board for carrying out a method for mounting components on a printed wiring board according to a first embodiment of the present invention. This printed wiring board includes a flexible printed wiring board 1 formed in a long cylindrical shape, and an electronic component 2 mounted inside the printed wiring board 1. FIG. 2 is an enlarged view of a portion A in FIG. In FIG. 2, the printed wiring board 1 is formed with a ground layer (for example, a copper foil layer) 1c sandwiched between an insulating layer 1a and an insulating layer 1b. The entire surface of the copper foil layer 1c is formed of a solid copper foil layer, and is connected to the ground potential. Conductive patterns (for example, copper foil layers) 1d and 1e for transmitting a power supply voltage and a signal are formed on the insulating layer 1a, and an electronic component 2 is connected to the copper foil layer 1e.

FIG. 3 is an enlarged view of a portion B in FIG. As shown in FIG. 3, the copper foil layer 1c is exposed on the end faces X and X ″.
By contacting X ″ and connecting the two copper foil layers 1c with the solder 3, the copper foil layers 1c on the end faces X and X ″ are electrically connected. FIG. 4 (a), (b), (c)
FIG. 2 is a manufacturing process diagram of the printed wiring board of FIG. 1. FIG.
After the electronic component 2 is mounted on the planar printed wiring board 1 as shown in FIG. 4A, a point Y is formed as shown in FIG.
Is a bending point, and the electronic component 2 is bent inside.
As shown in (c), one end face X of the printed wiring board 1
Is brought into contact with the other end face X ″. Thereafter, as shown in FIG. 3, by connecting the two copper foil layers 1c with the solder 3, the printed wiring board having the shape shown in FIG. 1 is completed.
In this component mounting method for a printed wiring board, the electronic component 2 and the copper foil layer 1c are electrically connected to the copper foil layer 1c on the end faces X and X ″ after the electronic component 2 is bent with the inside facing inward.
A printed wiring board having a structure in which d, 1e, and the like are surrounded by the copper foil layer 1c can be produced. This copper foil layer 1c is connected to the ground potential. Therefore, in the printed wiring board manufactured by this method, when the circuit formed inside is operating, the radiation noise and the external noise generated from the electronic component 2 and the copper foil layers 1d, 1e, etc. are caused by the copper foil layer 1c. Shielded,
There is an advantage that malfunction of the circuit is reduced and malfunction of an external electronic device is reduced.

Second Embodiment FIG. 5 is a perspective view of a printed wiring board for carrying out a method for mounting components on a printed wiring board according to a second embodiment of the present invention, and shows a first embodiment. Elements common to those in FIG. 1 are denoted by common reference numerals. In this printed wiring board, the copper foil layer 1c, which is a ground layer, has opposite ends a and b in front of the gap V surrounded by the own wiring board, for example, a plurality of conductive metals 3, 4, 5 of copper foil. Connected through. Further, also on the back surface (not shown) of the gap V,
Similarly, opposite ends are connected via a plurality of conductive metals. The smaller the spacing between the conductive metals 3, 4, and 5, the more the noise prevention effect is improved. However, the spacing is determined by the frequency of the noise that needs to be shielded.
In order to have an effect on noise above
It should be 1/4 of the wavelength of GHz (= 30 cm), that is, less than 7.5 cm. Other configurations are the same as those in FIG. In this method for mounting components on a printed wiring board, the ends a and b are connected via the conductive metals 3, 4, and 5, so that in addition to the advantages of the first embodiment,
There is an advantage that a printed wiring board with an improved shielding effect on the gap V can be produced.

Third Embodiment FIG. 6 is a cross-sectional view for carrying out a method for mounting components on a printed wiring board according to a third embodiment of the present invention. This printed wiring board has a flexible first
And a flexible second printed wiring board 12 disposed on the lower side. A conductive pattern (for example, a copper foil layer) 1 is formed on the printed wiring board 11.
1a is formed, and an electronic component 11b is connected to the copper foil layer 11a. Similarly, a conductive pattern (for example, a copper foil layer) 12a is formed on the printed wiring board 12, and an electronic component 12b is connected to the copper foil layer 12a. Each of the printed wiring boards 11 and 12 has a solid layer (not shown) similar to the copper foil layer 1c in FIG. 2 as a ground layer.
The printed wiring boards 11 and 12 are bent with the surfaces to which the electronic components 11b and 12b are connected inward, respectively.
The ends of each ground layer are electrically connected via the conductive metal 13. In this embodiment, a screw 14 is used as a means for this connection.

In this method of mounting components on a printed wiring board,
Similarly to the first embodiment, the copper foil layers 11a and 12a and the electronic components 11b and 12b are wrapped in the ground layer.
This ground layer is connected to a ground potential. Therefore, in the printed wiring board manufactured by this method, the electronic components 11
b, 12b and radiation noise and extraneous noise generated from the copper foil layers 11a, 12a, etc. are shielded by the ground layer,
There is an advantage that malfunction of the circuit is reduced and malfunction of an external electronic device is reduced.

Fourth Embodiment FIG. 7 is an external view of a personal computer which is an example of an electronic apparatus according to a fourth embodiment of the present invention. The personal computer includes a control unit 2 having a control circuit including a keyboard, a microprocessor, and the like.
1 and a display unit 22 such as a liquid crystal display. FIG. 8 is a sectional view taken along line CC of FIG. In FIG. 8, the housing of the control unit 21 includes an upper first housing piece (for example, a mold cover) 21a and a lower second housing piece (for example, a mold cover) 21b. . Then, the flexible first printed wiring board 21c is placed on the adhesive 2 along the inner surface of the mold cover 21a.
Attached by 1d. This printed wiring board 21c has a solid layer (not shown) similar to the copper foil layer 1c in FIG. 2 as a ground layer. Printed wiring board 21
c, a conductive pattern (not shown)
e is connected. Similarly, a flexible second printed wiring board 21f is attached along the inner surface of the mold cover 21b with an adhesive 21g. The printed wiring board 21f has a solid layer (not shown) as a ground layer. Inside the printed wiring board 21f,
The electronic component 21h is connected to a conductive pattern (not shown). Connectors 21i and 21j connected to the solid layers are attached to both ends of the printed wiring boards 21c and 21f, respectively. When the mold covers 21a and 21b are combined, the solid layers are connected to each other and set to the ground potential. It is to be connected.

FIG. 9 is an enlarged view of a portion D in FIG. As shown in FIG. 9, by overlapping the mold cover 21a and the mold cover 21b, the connector 21
i and 21j are connected, and the printed wiring board 21c and the printed wiring board 21f are connected. As a result, the ground layers of the printed wiring boards 21c and 21f are electrically connected to each other, and the entire circuit of the printed wiring boards 21c and 21f is wrapped in the ground layer. In this personal computer, the printed wiring boards 21c, 21c
The whole circuit of f is structured to be wrapped in the ground layer. Therefore, these printed wiring boards 21c, 21c
f, the electronic components 21
Radiation noise and extraneous noise generated from e, 21h, the conductive pattern and the like are shielded by the ground layer, so that there is an advantage that malfunction of the circuit is reduced and malfunction of external electronic equipment is reduced.

The present invention is not limited to the above embodiment,
Various modifications are possible. For example, there are the following modifications. (A) The printed wiring board 1 of FIG. 2 has insulating layers 1a and 1b.
And the ground layer 1c, but may be further composed of a multilayer insulating layer and a ground layer. (B) In FIG. 3, although the copper foil layers 1c on the end faces X and X ″ are connected and electrically connected, the electronic component 2
If the conductive patterns 1d and 1e are surrounded by the copper foil layer 1c, the ends of the copper foil layer 1c may not be connected. (C) In the printed wiring board of FIG. 6, similarly to FIG. 5, the opposite ends of the void surrounded by the own wiring board may be connected via a plurality of conductive metals. (D) As means for connecting the ends of the ground layers in the printed wiring board of FIG. 6, soldering, mechanical crimping, or the like may be used instead of the screw 14. (E) The electronic device according to the fourth embodiment is not limited to a personal computer.

[0016]

As described above in detail, according to the first aspect, it is possible to produce a printed wiring board in which electronic components and conductive patterns are shielded by a solid ground layer connected to the ground potential. . Therefore, a printed wiring board with reduced radiation noise and reduced malfunction due to external noise can be produced. According to the second aspect, a printed wiring board having a structure in which a conductive pattern, electronic components, and the like are wrapped in a ground layer can be produced. Therefore, similarly to the first invention, a printed wiring board with reduced radiation noise and reduced malfunction due to external noise can be produced. Therefore, when a circuit formed in the printed wiring board is operating, radiation noise and external noise generated from each electronic component and each conductive pattern are shielded by the respective ground layers, thereby reducing malfunction of the circuit. In addition, malfunctions of external electronic devices are reduced. According to the third aspect, it is possible to produce a printed wiring board in which opposing ends of a gap surrounded by the own wiring board are connected via a plurality of conductive metals. Therefore, in addition to the effect of the first invention, a printed wiring board having an improved effect of shielding a void can be produced. According to the fourth aspect, the entire circuit of the first and second printed wiring boards has a structure wrapped by the ground layer. Therefore, when the circuits formed in these printed wiring boards are operating, Radiation noise and external noise generated from electronic components and conductive patterns are shielded by the ground layer, so that malfunction of the circuit can be reduced and malfunction of external electronic devices can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a printed wiring board according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an enlarged view of a portion B in FIG.

FIG. 4 is a manufacturing process diagram of the printed wiring board of FIG. 1;

FIG. 5 is a perspective view of a printed wiring board according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a printed wiring board according to a second embodiment of the present invention.

FIG. 7 is an external view of a personal computer according to a third embodiment of the present invention.

FIG. 8 is a sectional view taken along line CC of FIG. 7;

FIG. 9 is an enlarged view of a portion D in FIG. 8;

[Explanation of symbols]

 Reference Signs List 1 printed wiring board 1a, 1b insulating layer 1c ground layer 1d, 1e conductive pattern 2 electronic component 3, 4, 5 conductive metal 11, 12 printed wiring board 11a, 12a conductive pattern 11b, 12b electronic component 21a, 21b mold cover 21c , 21f Printed wiring board 21e, 21h Electronic component V Void

Claims (4)

[Claims] 1. A flexible printed wiring board having a ground layer constituting a bottom surface and a pattern layer on which an insulating layer and a conductive pattern are alternately laminated on the ground layer, and on which electronic components are mounted. Used, the ground layer is constituted by a solid conductive layer on the entire surface, the uppermost surface of the printed wiring board is constituted by the pattern layer, the electronic component is mounted on the pattern layer, and the electronic component is on the inside. Wherein the electronic component is surrounded by the solid layer and the solid layer is connected to a ground potential. 2. A flexible first and a second flexible board for mounting an electronic component, comprising: a ground layer constituting a bottom surface; and a pattern layer on which an insulating layer and a conductive pattern are alternately laminated on the ground layer. 2, each ground layer is made up of a solid conductive layer on the entire surface, and the uppermost surface of each printed wiring board is made up of the pattern layer, and the electronic component is placed on each pattern layer. Each mounted, each electronic component is bent inside with each inside, and each electronic component is surrounded by connecting ends of each solid layer, and each solid layer is connected to a ground potential. To mount printed wiring boards. 3. The solid layer, wherein opposing ends of a void surrounded by a wiring board are connected via a plurality of conductive metals, and each of the conductive metals has a wavelength of noise that needs to be shielded. 3. The method for mounting components on a printed wiring board according to claim 1, wherein the components are provided at a position less than 1/4 of the distance. 4. An electronic apparatus having a housing formed by combining first and second housing pieces, and an electronic component built in the housing, wherein a ground layer forming a bottom surface; An insulating layer alternately laminated on the ground layer and a pattern layer on which a conductive pattern is formed, comprising: flexible first and second printed wiring boards on which electronic components are mounted; The entire surface is formed of a solid conductive layer, and the uppermost surface of each of the printed wiring boards is formed of the pattern layer, and the electronic components are mounted on the respective pattern layers. Attaching each printed wiring board along the inner surface of each housing piece,
The electronic device according to claim 1, wherein when the casing pieces are combined, the solid layers are connected to each other and connected to a ground potential.