JP2001111282A - Electromagnetic wave shield molded product and manufacturing method therefore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide electromagnetic wave shield molded products and its manufacturing method which correspond to high frequency, without deformation due to its making contact with components, etc., and can be set at an appropriate position during assembly and improve the restoration property of shape or compressed permanent deformation, etc., and no largescaled working or facility is needed. SOLUTION: This product is provided with a shielding enclosure 4, which is connected with the ground layer 2 of a printed board 1 and covers an electromagnetic wave generating source 3 and a shield molded article 7 with an approximately U-shaped section engaged with a connection rib 6 for the ground layer 2 of the shielding enclosure. In addition, the shield molded article 7 is composed of a base of 0.025 to 1 mm in thickness with a through-hole and a conductive polymer elastic body which is laminated on both surfaces of a substrate for integration, and a pair of polymer elastic bodies are connected integrally by means of the through-hole of the base. Each of their volume resistivities is set to 0.01 to 5 Ω.cm and Shore hardness to 20 to 70 Hs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield molded product used for various electronic devices such as a cellular phone, a wireless device, a measuring instrument, a computer, and a control device for an automobile, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In various electronic devices such as cellular phones, wireless devices, and computers, a signal transmission unit, a power supply unit, and the like radiate electromagnetic waves during operation, and the electromagnetic waves may cause malfunction of electronic components, Shielding is required as it reduces normal function. Therefore, conventionally, as shown in FIG. 9, the connection rib 6 of the shield housing 4 having the conductive layer 5 on the inner surface is screwed to the ground layer 2 on the surface of the printed circuit board 1 via a gasket or a fastener 16 for shielding. The shield case 4 covers the electromagnetic wave generation source 3 made of electronic components of the printed circuit board 1, and the conductive layer 5 of the shield case 4 reflects and absorbs or attenuates unnecessary electromagnetic waves indicated by arrows. Then, the electronic component is sealed in the shield housing 4 to protect the electronic components from electromagnetic waves, radio waves, or magnetic fields.

However, in recent years, radio waves have become higher in frequency,
Moreover, since it is necessary to process a plurality of types of radio waves in one electronic device, the shielding means of FIG. 9 may not be sufficient in some cases. For example, as shown in the drawing, the printed circuit board 1 and the shield housing 4 are based on dimensional tolerances and assembling tolerances during assembly.
A small gap S is generated between the small gap S
Antenna receives a radio wave as an antenna. This antenna phenomenon occurs at shorter intervals as the frequency of the radio wave used increases, and as a result, electromagnetic waves leak out of the shield housing 4 and adversely affect electronic components. In addition, when the printed circuit board 1 and the shield housing 4 are in discontinuous contact with each other, there is not a small possibility that noise interference will occur.

[0004] As a method of solving such an adverse effect,
Recognition and recognition by testing the characteristics of test equipment after the completion of electronic equipment
There is a method of coping with the problem and a method of completely shielding the electromagnetic wave generating source 3 from the shield housing 4 from the design stage and grounding the shield housing 4 on the ground layer 2 of the printed circuit board 1 without fail. The former method is
Although it is considered that it is difficult to predict the occurrence of the harm because the harm is caused by the mechanism shape and performance of the electronic device, it is not the best method. On the other hand, the latter method does not cause any adverse effects, and thus does not need to be predicted, and can be said to be the best method. Therefore,
Various development studies have been made on the latter method.

A specific example of this latter method is as follows.
There are (1), (2), (3), (4) and (5). First, (1)
The pressed metal sheet is bent into a substantially pantograph shape to form a small spring member, and a plurality of such spring members are mounted and welded to predetermined portions of the ground layer 2 of the printed circuit board 1 and the plurality of spring members are welded through the plurality of spring members. Shield housing 4
The connection rib 6 is connected, and the elasticity of the spring member is used to absorb the dimensional tolerance and the assembly tolerance, so that the shield housing 4 is reliably grounded.

Next, (2), as shown in FIG. 10, corresponds to the plane shape of the connection rib 6 of the shield housing 4 by 0.1.
The thin metal plate 17 having a thickness of about mm is press-worked, and a conductive coating is applied to the thin metal plate 17.
7 is bent to form a plurality of spring members 18 which can be undulated and oscillated. The thin metal plate 17 is mounted on the ground layer 2 of the printed circuit board 1, and the shield housing 4 is interposed via the thin metal plate 17. In this method, the dimensional tolerance and the assembly tolerance are absorbed by utilizing the elasticity of the spring member 18 and the shield housing 4 is reliably grounded.

Next, (3) two-color molding of the conductive rubber elastic body 19 into a sheet shape using a resin and a conductive elastomer containing conductive carbon and metal particles is performed. A gasket is formed by punching (see FIG. 11) so as to correspond to the planar shape of the connection rib 6 of the shield housing 4. The conductive rubber elastic body 19 is mounted on the ground layer 2 of the printed circuit board 1, and the conductive rubber The connection rib 6 of the shield housing 4 is connected via the elastic body 19, and the elasticity of the conductive rubber elastic body 19 is used to absorb dimensional tolerances and assembly tolerances, and the shield housing 4 is reliably grounded. is there.

Next, in (4), the connection rib 6 of the plastic shield housing 4 and the conductive rubber elastic body are integrally formed, and the dimensional tolerance and the assembly tolerance are adjusted by utilizing the elasticity of the conductive rubber elastic body. This is a method of absorbing and reliably grounding the shield housing 4. And (5), a raw material of a rubber elastic body containing conductive carbon and metal particles is applied to the connection rib 6 of the shield housing 4 and dried and cured, and the dimensions are obtained by utilizing the elasticity of the formed conductive rubber elastic body. This is a method of absorbing the tolerance and the assembly tolerance and grounding the shield housing 4 reliably.

In order to confine the electromagnetic waves in the shield housing 4, a specific volume resistivity (depending on the frequency, but generally not more than 5Ω · cm) is required.
Surrounding the shield housing 4 with a conductor having the following characteristics, and reliably ground the ground layer 2 of the printed circuit board 1 to at least an average shield effect of 30 to 60 dB or more.
(30dB is minimum shield, 60-90dB is above average, 90dB and above is best shield)
(See FIG. 12). In response to this, the metal sheet 17, the spring member 1
8, or the volume resistivity value of the conductive rubber elastic body 19 is 5
Ω · cm or less.

[0010]

SUMMARY OF THE INVENTION
The methods (1) and (2) have a problem that the spring member and the thin metal plate are easily deformed by contact with other parts during transportation or use, and are easily damaged. In addition, the elasticity of the spring member has a limit, and since it is a partial connection with a fixed dimensional interval, it may not be possible to sufficiently cope with high frequencies. In the method (3), since the thickness of the conductive rubber elastic body 19 is usually 0.5 to 2.5 mm, the planar shape holding property is poor, and the conductive rubber elastic body 19 is placed at an appropriate position during assembling. There is a possibility that it cannot be implemented. In addition, since the conductive rubber elastic body 19 is required to have contradictory physical properties such as a volume resistivity and elasticity and a compression set characteristic (shape restoring property upon compression release), selection of conductive carbon and metal particles is required. In addition, it is extremely difficult to set the mixing ratio, and depending on the mixing ratio of the conductive carbon or metal particles, the resilience of the shape is deteriorated and the use may not be possible.

In the method (4), the connection rib 6 of the shield housing 4 and the conductive rubber elastic body are integrally molded. Therefore, although ideal, the material for the integral molding (thermoplastic, thermosetting rubber elastic body) is used. Depending on the properties of the (body), there is a possibility that the compression set is deteriorated or the elasticity is lacking. In addition, the hardness is high and there is a problem in cost. Further, in the method (5), although simple, the connection rib 6 of the shield housing 4 is not used.
Since the raw material of the rubber elastic body is applied using a discharge device or the like and dried and cured, the operation and equipment become large, and there is a great problem in material management and quality control.

The present invention has been made in view of the above-mentioned problems, and does not easily deform due to contact with parts, can sufficiently cope with high frequencies, and can be set at an appropriate position when assembled. In addition, an object of the present invention is to provide an electromagnetic wave shield molded product that can obtain sufficient shape resilience, permanent compression set, elasticity, or hardness, and does not particularly require a large-scale operation or equipment, and a method for manufacturing the same. .

[0013]

According to the first aspect of the present invention, in order to achieve the above object, a shield housing attached to a ground layer of a substrate and covering an electromagnetic wave generation source;
And a shield molded product provided in the shield housing.
A base material with a through hole having a thickness of 5 to 1 mm, and a conductive polymer elastic body integrated with at least one surface of the base material, and a volume resistivity value of the polymer elastic body In addition to 0.01 to 5 Ω · cm, the Shore A hardness of the elastic polymer is 20 to 70 Hs.

[0014] The above-mentioned shield molded product is composed of the above-mentioned base material and the above-mentioned polymer elastic bodies laminated on both sides of the base material, respectively. Preferably, the shield molded product is formed to have a substantially U-shaped cross section so that the shield molded product can be fitted to a connection rib for a ground layer of the shield housing. Further, the shield molded product, the base material, and a polymer elastic body laminated on one surface of the base material, integrally formed with a through hole of the base material and a part of the polymer elastic body, It is preferable that the shield molded product is bent and integrally formed with the conductive layer of the shield housing, and a part of the polymer elastic body is brought into contact with the conductive layer.

According to the present invention, in order to achieve the above object, a frame interposed between a plurality of substrates and surrounding an electromagnetic wave generation source, and the plurality of substrates fitted to the frame to electrically connect the plurality of substrates. And a shield molded product that is electrically connected to the shield molded product.
A base material having a through hole having a thickness of 025 mm to 1 mm, and a conductive polymer elastic body which is integrated by being superposed on one surface of the base material; And a volume elastic resistance value of the polymer elastic body is set to 0.01 to 5 Ω · cm, and a Shore A hardness of the polymer elastic body is set to 20 to 70 Hs. I have.

Further, in the invention according to claim 5,
In order to achieve the above object, a through hole is provided in a base material having a thickness of 0.025 to 1 mm, and a conductive polymer elastic body is provided on at least one surface of the base material. To form a shield molded product by bending into a predetermined shape while forming a through hole of the base material and a part of the polymer elastic body, and forming the shield molded product. The volume resistivity of the body is 0.01 to 5Ωcm
And the Shore A hardness of the elastic polymer is 20 to 70H
s.

Here, the substrate in the claims includes a printed circuit board, an electromagnetic wave shield printed wiring board,
Examples include a flexible substrate or a build-up wiring board. The shield housing and frame may or may not be made of plastic. The cross-sectional shape of the shield molded product, in other words, the planar shape, can be appropriately changed according to the shape of the ground layer and the shield housing. Also,
The through-hole in the substrate may be any one or more of a plurality of holes, may be a round hole, or may be a slot made of a linear slit or the like having a width of 1 mm or less. In addition, the substantially U-shaped cross section has C
Included are U-shaped, U-shaped, and similar shapes.

According to the first aspect of the present invention, if a shield molded article is provided in the shield housing and this shield molded article is connected to the ground layer of the substrate and grounded, the shield casing reflects and absorbs unnecessary electromagnetic waves. It can be attenuated and enclosed in a shielded housing to effectively protect a mobile phone, a wireless device, a measuring instrument, a computer, or a control device for an automobile or its electronic components from an electromagnetic wave, a radio wave, and a magnetic field. According to the second aspect of the invention, if the shield molded product is fitted into the connection rib of the shield housing, and the shield molded product is fixed to the ground layer of the printed circuit board and grounded,
The conductive layer of the shield housing reflects and attenuates or attenuates unnecessary electromagnetic waves and seals them in the shield housing, so that electronic components and the like can be effectively protected from electromagnetic waves and the like. At this time, a shield molded product having elasticity is interposed between the substrate and the shield housing, and if there is a gap, it is filled.

According to the fourth aspect of the present invention, if a shield molded product is fitted into a frame, and the frame provided with the shield molded product is interposed between a plurality of printed circuit boards and made conductive, electromagnetic wave and the like can be prevented. It is possible to effectively protect a mobile phone, a wireless device, a measuring instrument, a computer, or a control device for a vehicle and its electronic components. At this time, an elastic shield molded product is interposed between the plurality of substrates, and if there is a gap, it is filled.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1 to FIG. 2, a shield housing 4 that covers the plurality of electromagnetic wave sources 3 and a shield molded product 7 that fits into the connection ribs 6 of the shield housing 4.
The shield molded product 7 is composed of a bendable base material 8 and a conductive polymer elastic body 10 which is laminated and bonded to both the front and back surfaces of the base material 8, respectively.

As shown in FIG. 1, a printed circuit board 1 has a ground layer 2 patterned on a surface of the printed circuit board 1 in a predetermined circuit pattern, and a plurality of electromagnetic wave sources 3 made of electronic components.
Has been implemented. As shown in FIG. 1, the shield housing 4 is made of, for example, AB which is excellent in impact strength, heat resistance, design, etc.
Using a molding material such as S, PC, PA, PES, or TPEI, or a metal plate, it is sectioned into a box shape having a substantially E-shaped cross section, and a thin conductive layer 5 made of an electromagnetic wave shielding material is formed on the entire inner surface by vapor deposition or sputtering. Or a film is formed by a plating method or the like. The partition wall of the shield housing 4 is a connection rib 6, and the connection rib 6 is generally formed to have a width of about 0.2 to 2 mm. Further, as shown in FIG. 2, the shield molded product 7 is formed into, for example, a substantially rectangular shape in a plan view, and is formed into a substantially U-shaped cross section that opens downward.

The substrate 8 is made of a molding material such as PEN which is excellent in dimensional stability, electrical properties, lightness and the like.
It is formed into a pressurized and heatable film having a thickness of 025 to 0.2 mm, and a plurality of through-holes 9 having a diameter of 1 mm or less are regularly arranged and formed. As a molding material for the base material 8, in addition to PEN, P
ET, PC, PP, PA, PPS, etc. can be used, but PEN is most suitable from the viewpoint of versatility and cost. In addition, as a material of the base material 8, 0.025
It is also possible to use a thin metal plate having a thickness of １1 mm, preferably 0.3-1 mm and corresponding to the connection rib 6 of the shield housing 4.

The polymer elastic body 10 is formed by mixing a thermoplastic resin, a thermosetting resin, an elastomer and conductive particles, and is used in an amount of 0.1 to 1 mm, preferably 0.2 to 0.1 mm.
Molded into a bendable cross-section plate having a thickness of 8 mm,
Conductive connection is made integrally through a plurality of through holes 9 in the base material 8. As the thermoplastic resin, EPDM, IIR, B
Examples thereof include R, NBR, U, F, and IR. Examples of the thermosetting resin include a styrene-based resin and a polyester-based resin. However, silicone rubber is preferred in consideration of heat resistance, compression set characteristics, hardness range, conductivity, and the like.

As the conductive particles, silver particles, nickel particles, carbon fiber particles and the like can be used. However, from the viewpoint of a change in resistance value due to oxidation, it is desirable to use various low-resistance carbon fiber particles in combination with metal-based particles. Typical examples are carbon fiber particles, Ketchin Black EC
-DJ500 (manufactured by Lion Corporation).

Each polymer elastic body 10 has a volume specific resistance of 0.01 to 5 Ω · cm in order to obtain a sufficient shielding effect.
And the Shore A hardness is in the range of 20 to 70 Hs. Means for imparting elasticity to the polymer elastic body 10 include foaming of various elastomers and adjustment of the blending weight of the conductive material. Shore A hardness is 20-70H
Although it is free within the range of s, in order to improve stability,
The range of 30 to 50 Hs is optimal.

Next, FIGS. 4 (a), (b), (c), (d),
(e), (f), and (g), a method of manufacturing the shield molded product 7 will be described. First, a base material 8 having a thickness of 0.025 to 1 mm is prepared. A plurality of through holes 9 are arranged in the thickness direction using a punching die, a needle, or the like (see FIG. 4A). After the through holes 9 are provided in the base material 8, the raw materials of the conductive polymer elastic body 10 are provided on both surfaces of the base material 8 by laminating, bonding, or the like (FIG. 4).
(see FIG. 4 (b)), these are clamped in a mold 12 of a press and heat forming machine (press forming machine), pressurized and heated (see FIG. 4 (c)), and a base material 8 and a pair of polymer elastic bodies are pressed. Then, the plurality of through holes 9 of the base material 8 and the portions 11 of the respective polymer elastic bodies 10 are integrally formed (see FIG. 4D).

In the above operation, if it is difficult to integrally form the base material 8 and the elastic polymer 10 like a polyester film and a urethane rubber, it is necessary to perform a primer treatment on the base material 8 in advance. Efficiency can be improved. Further, the base material 8 and the pair of polymer elastic bodies 10 may be integrated at about 180 ° C. by a pressure heating method using the mold 12,
It is not limited to this. For example, the base material 8
And a pair of polymer elastic bodies 10 in a mold 12A of an injection molding machine.
To improve productivity, quality stability, applicability, etc. (see FIG. 5). It is also possible to integrate them with a Banbury mixer (not shown) or the like.

Next, the drawing die 1 which is cut into irregularities so as to correspond to the planar shape of the connection rib 6 of the shield housing 4.
In FIG. 3, the tentative shield molded product 7 obtained by the above operation is clamped and set, and the shield molded product 7 is drawn and formed into a flat U-shaped cross section in a flat Japanese character shape while heating under pressure (FIG. 4 (e)). )
Then, if unnecessary ends and edges of the shield molded product 7 are appropriately removed by a punching method or the like, the shield molded product 7 bent into a predetermined shape can be obtained (FIG. 4F).
reference). At this time, the shield molded product 7 is
Is drawn into a substantially U-shaped cross section in a size range of 100% to 130% of the size of the connection rib 6 of FIG.

After manufacturing the shield molded product 7, the shield molded product 7 is fitted over all the connection ribs 6 of the shield housing 4 (see FIG. 4 (g)), and the shield molded product 7 is connected to the ground layer of the printed circuit board 1. 2, if the ground is fixed to the surface contact state so that the resistance value becomes low, the conductive layer 5 of the shield housing 4 reflects and attenuates or attenuates unnecessary electromagnetic waves and is sealed in the shield housing 4 without leakage. Electronic components can be protected very effectively from electromagnetic waves, radio waves, or magnetic fields. For fixing the shield housing 4, a fastener 16 or a clamp member (not shown) can be used. At this time, the shield molded product 7 having elasticity is interposed between the printed board 1 and the shield housing 4 in a stable state, and the gap S
Is absorbed and filled, it is possible to effectively prevent the occurrence of a small gap S and the discontinuous contact between the printed circuit board 1 and the shield housing 4.

According to the above configuration, the spring member and the thin metal plate which are easily deformed by contact with other parts are not omitted or exposed, so that displacement, deformation and damage can be effectively suppressed and prevented. And stable conductivity can be obtained with a low pressure contact force. In addition, the polymer elastic body 10
The use of can greatly improve the elasticity,
Moreover, the volume elastic resistance value of the polymer elastic body 10 bent at the time of installation is 0.01 to 5 Ω · cm, and the contact area is greatly increased instead of the partial connection at a fixed dimensional interval. It is possible to sufficiently cope with the high frequency used in the method. Also, since the shield molded product 7 is fitted into the connection rib 6 of the shield housing 4 in a small space, the mounting property is improved.
It is possible to improve the work efficiency and facilitate the handling.

Further, since the polymer elastic body 10 is superposed on the base material 8, the planar shape can be well maintained, and the proper mounting of the shield molded product 7 at the time of assembling can be greatly expected. Also, if silicone rubber or the like is used as the polymer elastic body 10, it is quite good in terms of compression set, heat resistance, cold resistance, chemical resistance, weather resistance, ozone resistance, electrical properties, hardness, and cost. Results can be obtained. further,
Since there is no need to apply a rubber elastic material to the connection rib 6 of the shield housing 4 with a discharge device or the like and to dry and cure the material, work and equipment are greatly simplified, and no large scale is required.
Furthermore, unlike the case where the conductive rubber elastic body 19 is manufactured by a two-color molding method or a dispensing method, a high-quality and inexpensive shield molded product 7 that does not involve the transport of parts during product manufacture.
Can be suggested.

FIGS. 6 and 7 show another embodiment of the present invention. In this case, the shield molded product 7 is
The base material 8 includes a flexible base material 8 and a conductive polymer elastic body 10 laminated on one surface of the base material 8. Are fitted into each other, and are integrally molded. The shield molded product 7 is bent to correspond to all the conductive layers 5 of the metal shield housing 4 to be integrally molded, and a part 1 of the polymer elastic body 10 is formed in the conductive layer 5.
1 are brought into contact with each other to ensure conductivity. The other parts are substantially the same as those in the above-described embodiment, and a description thereof will be omitted.

In this embodiment, the same operation and effect as those in the above embodiment can be expected. Further, since there is no need to insert the shield molded product 7 into the connection rib 6 of the shield housing 4, mounting efficiency and work efficiency are reduced. Obviously, the simplicity and ease of handling can be further improved. In addition, a reduction in the weight of the shield housing 4 can be expected.

FIG. 8 shows a second embodiment of the present invention. In this case, a plastic flat frame which surrounds a plurality of electromagnetic wave sources 3 interposed between a pair of printed circuit boards 1 is shown. And a shield molded product 7 having a substantially U-shaped cross section, which is fitted to the front, rear, left and right sides of the frame 15 and electrically connects the pair of printed circuit boards 1 to each other. A base material 8 having a thickness of 0.25 to 1 mm and having a plurality of through holes 9 in contact with the frame 15, and being laminated and integrated on one surface of the base material 8, and integrated with the ground of the pair of printed circuit boards 1. And a conductive polymer elastic body 10 which is in pressure contact with a conductive portion such as the layer 2 or an electrode portion. The other parts are substantially the same as those in the above-described embodiment, and a description thereof will be omitted.

In this embodiment, the same function and effect as those of the above embodiment can be expected. Further, even when a plurality of printed circuit boards 1 are used, deformation and damage can be effectively suppressed and prevented, and a low pressing force can be obtained. And a stable electrical connection can be obtained. In addition, since the partial connection is not performed at a fixed interval, it is possible to sufficiently cope with a high frequency. Further, since the small shield molded product 7 is fitted into the frame 15, mounting efficiency, work efficiency, and ease of handling can be greatly expected.

[0036]

EXAMPLES Examples of the electromagnetic wave shield molded product according to the present invention will be described below along with comparative examples, and evaluation and examination will be made. Example 1 First, a base material 8 having a thickness of 0.1 mm was prepared, and a plurality of through-holes 9 having a diameter of 0.5 mm and alignment holes were provided in the base material 8 by a punching die. As the base material 8, a 0.1 mm thick polyester film sheet, Lumirror
(Manufactured by Toray Industries, Inc.). Further, the plurality of through holes 9 were set at intervals of 3 mm. When the through holes 9 are provided in the base material 8 in this manner, the base material 8 is inserted into the mold 12A of the injection molding machine and clamped, and the liquid reaction type silicone rubber KE1940-3 is formed.
0 (manufactured by Shin-Etsu Chemical Co., Ltd.) and 20 parts by mass of conductive carbon ketchin black (manufactured by Lion Corporation) are injected with the raw material of the conductive polymer elastic body 10,
And a pair of polymer elastic bodies 10 were integrally formed to integrally form the plurality of through holes 9 of the base material 8 and a part 11 of each polymer elastic body 10. The molding conditions at this time were an injection pressure of 15 MPa, an injection temperature of 120 ° C., and an injection time of 40 s.

Next, a depth of 1.5 m, which is cut into irregularities so as to correspond to the planar shape of the connection rib 6 of the shield housing 4.
The shield molded product 7 obtained in the above operation was clamped and set in a draw mold 13 of m, and the shield molded product 7 was drawn and formed into a substantially U-shaped cross section while heating under pressure. The molding conditions were a molding temperature of 120 ° C. and a molding time of 20 s.
After that, unnecessary ends, edges, and the like of the shield molded product 7 were appropriately removed by a punching method or the like and finished to obtain a shield molded product 7 bent into a predetermined shape. This shield molded product 7
The total thickness is 0.7 mm, the thickness of each polymer elastic body 10 is 0.3 mm, and the resistance value when assuming a 0.3 mm press-fit between the printed circuit board 1 and the shield housing 4 is 2Ω.

Example 2 First, the base material 8 having a thickness of 0.1 mm was prepared.
The base material 8 was subjected to a primer treatment using Primer C (manufactured by Shin-Etsu Chemical Co., Ltd.), air-dried at room temperature for 30 minutes, and a plurality of through-holes 9 having a diameter of 0.7 mm were provided in a punching die. Was. At this time, the plurality of through holes 9 were set at intervals of 5 mm. After the through holes 9 are provided in the base material 8, the raw materials of the conductive polymer elastic body 10 are respectively provided on both surfaces of the base material 8,
These are clamped in a mold 12 of a press and heat molding machine, heated under pressure, and the base material 8 and a pair of polymer elastic bodies 10 are integrated to form a plurality of through holes 9 in the base material 8 and each polymer. Part 1 of elastic body 10
And 1 were integrally formed.

As the polymer elastic body 10, silicone rubber compound KE941U silver particles and carbon EC-D
J50 (manufactured by Lion Akzo Co., Ltd.) was kneaded at a ratio of 3: 7 with respect to the silicone rubber compound in an amount of 5 material parts,
Sheets cut to the specified thickness were used. The molding conditions are a molding temperature of 180 ° C. and a molding time of 4 minutes.

Next, a depth of 1.3 m, which is cut into irregularities so as to correspond to the planar shape of the connection rib 6 of the shield housing 4.
The shield molded product 7 obtained in the above operation was clamped and set in a draw mold 13 of m, and the shield molded product 7 was drawn and formed into a substantially U-shaped cross section while heating under pressure. The molding conditions were a molding temperature of 130 ° C. and a molding time of 30 s.
After that, unnecessary ends, edges, and the like of the shield molded product 7 were appropriately removed by a punching method or the like and finished to obtain a shield molded product 7 bent into a predetermined shape. The shield molded product 7 obtained in Example 1 and Example 2 and the comparative example shown in FIGS. 10 and 11 were tested, and the results are summarized in Table 1.

[0041]

[Table 1]

As is apparent from Table 1, the shield molded product 7 obtained in Examples 1 and 2 was confirmed by incorporating it into a model for North America (digital TDMA / analog dual band) and confirming the workability of installation and communication failure. Is a spring member 1
As compared with No. 8 and the conductive rubber elastic body 19, very good workability in assembling and shape retention during transportation could be obtained. In addition, no interference of electromagnetic waves occurred, and good communication results could be obtained. On the other hand, the comparative example incorporated in the tester is the conductive rubber elastic body 19 formed by two-color molding with the spring member 18, and the conductive rubber elastic body 19 is considered to have twisted at the time of assembling. Printed circuit board 1
At the time of opening from, it was deformed.

[0043]

As described above, according to the present invention, the shield molded product does not easily deform due to contact with other parts or the like, and can sufficiently cope with high frequencies. There is an effect that the article can be set at an appropriate position. In addition, sufficient shape resilience, permanent compression set, elasticity, or hardness can be obtained, and large-scale operations and equipment can be omitted.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view showing an embodiment of an electromagnetic wave shield molded product according to the present invention.

FIG. 2 is a perspective view showing an embodiment of an electromagnetic wave shield molded product according to the present invention.

FIG. 3 is a partial cross-sectional explanatory view showing an embodiment of an electromagnetic wave shield molded product according to the present invention.

FIG. 4 is an explanatory view showing an embodiment of a method for manufacturing an electromagnetic wave shield molded product according to the present invention. FIG. 4 (a) is a cross-sectional explanatory view showing a state in which through holes are juxtaposed in a base material, and FIG. Cross-sectional explanatory view showing a state in which the raw material of the conductive polymer elastic body is provided on both sides of the base material, respectively, (c) diagram is a cross-sectional explanatory view showing a state where the mold is clamped and heated under pressure, ( FIG. d) is a cross-sectional explanatory view showing a state in which the base material and the polymer elastic body are integrated, and (e) is a cross-sectional explanatory view showing a state in which the shield molded product is drawn and formed into a substantially U-shaped cross section while being heated under pressure. FIG. 1 (f) is a cross-sectional explanatory view showing a shield molded product bent into a predetermined shape, and FIG. 2 (g) is a cross-sectional explanatory diagram showing a state where the shield molded product is fitted into a connection rib of a shield housing.

FIG. 5 is an explanatory cross-sectional view showing a state in which a base and an elastic polymer are integrated by an injection molding method in an embodiment of the electromagnetic wave shield molded product according to the present invention.

FIG. 6 is a partial cross-sectional explanatory view showing another embodiment of the molded product of the electromagnetic wave shield according to the present invention.

FIG. 7 is an explanatory sectional view showing another embodiment of the molded product of the electromagnetic wave shield according to the present invention.

FIG. 8 is an explanatory perspective view showing an embodiment of an electromagnetic shield molded product according to the second invention of the present invention.

FIG. 9 is a sectional view showing a conventional electromagnetic wave shielding means.

FIG. 10 is a perspective explanatory view showing a conventional thin metal plate for electromagnetic wave shielding.

FIG. 11 is a perspective view showing a conventional conductive rubber elastic body for electromagnetic wave shielding.

FIG. 12 is an explanatory diagram showing a relationship between a shielding effect and a volume specific resistance value.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed circuit board (board) 2 Ground layer 3 Electromagnetic wave generation source 4 Shield housing 5 Conductive layer 6 Connection rib 7 Shield molded product 8 Base material 9 Through hole 10 Polymer elastic body 11 Part of polymer elastic body S Gap

Claims (5)

[Claims] 1. An electromagnetic shield molded product comprising: a shield housing attached to a ground layer of a substrate and covering an electromagnetic wave generation source; and a shield molded product provided in the shield housing. A base material having a through hole having a thickness of 0.025 to 1 mm, and a conductive polymer elastic body integrated on at least one surface of the base material, and a volume resistivity of the polymer elastic body The value is 0.01-5Ωcm
And the Shore A hardness of the elastic polymer is 20
An electromagnetic wave shield molded product characterized by having a pressure of 70 to 70 Hs. 2. The shield molded article is composed of the base material and the polymer elastic bodies laminated on both sides of the base material, respectively, and the pair of polymer elastic bodies is formed through a through hole of the base material. 2. The electromagnetic shield molded product according to claim 1, wherein the shield molded product is formed to have a substantially U-shaped cross section so as to be fitted to a connection rib for a ground layer of the shield housing. 3. The shield molded product is composed of the base material and a polymer elastic body laminated on one surface of the base material, and a through hole of the base material and a part of the polymer elastic body are integrated. 2. The electromagnetic wave shield molded product according to claim 1, wherein the shield molded product is bent and integrally formed with the conductive layer of the shield housing, and a part of the polymer elastic body is brought into contact with the conductive layer. 4. An electromagnetic wave shield molded product comprising a frame interposed between a plurality of substrates and surrounding an electromagnetic wave generation source, and a shield molded product fitted to the frame and electrically conducting the plurality of substrates. The shield molded product is composed of a base material having a through hole having a thickness of 0.025 to 1 mm, and a conductive polymer elastic body which is integrated on one surface of the base material. The through-hole of the base material and a part of the polymer elastic body are formed integrally with each other to have a volume resistivity value of 0.01 to 5 Ω · cm of the polymer elastic body. Hardness 20-70
An electromagnetic wave shield molded product characterized by Hs. 5. A through-hole is provided in a base material having a thickness of 0.025 to 1 mm, a conductive polymer elastic body is provided on at least one surface of the base material, and the base material and the polymer elastic body are connected to each other. Integrally forming the through hole of the base material and a part of the polymer elastic body, and bending the molded article into a predetermined shape to form a shield molded article. A method for producing a molded electromagnetic wave shield, wherein the volume resistivity is 0.01 to 5 Ω · cm, and the Shore A hardness of the elastic polymer is 20 to 70 Hs.