JP3524034B2 - Electromagnetic wave shielding structure and electromagnetic wave shielding method - Google Patents

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 structure and an electromagnetic wave shield method for shielding electromagnetic waves entering and exiting a single or a plurality of electronic parts mounted on a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, it is prevented that an electromagnetic wave from the outside is superimposed as noise on a signal input to or output from an electronic component, or an electromagnetic wave generated by the electronic component itself is superimposed on another signal as noise. Therefore, it is considered to shield the electromagnetic waves entering and exiting the electronic component. As such an electromagnetic wave shield structure, there is known a structure in which a single or a plurality of electronic components mounted on a printed circuit board are covered with a metal case from above. Further, in this case, the metal case is connected to the ground electrode of the printed circuit board so that a capacitor is not formed between the metal case and the printed circuit board and adversely affects the electronic parts.

[0003]

However, even if it is initially determined that such an electromagnetic wave shield is not necessary and various electronic components are mounted on the printed circuit board, the electromagnetic wave shield for some electronic components is necessary later. There are many cases where the sex is known. In this case, since many electronic components are already mounted on the printed circuit board, it is extremely difficult to cover the above-mentioned metal case with the desired electronic component and solder it to the ground electrode. In addition, the metal case is individually made, for example, to a size according to the size of the electronic component or, when simultaneously covering a plurality of electronic components, the arrangement of the electronic components. Therefore, the cost required for the electromagnetic wave shield is also high.

[0004] Therefore, the present invention is to provide an electromagnetic wave shield structure and the electromagnetic wave shielding method which can easily shield the electromagnetic waves into and out of the electronic component even from after mounting electronic components on a printed circuit board, the electromagnetic shield The purpose of the present invention is to satisfactorily reduce the cost required for the electromagnetic wave shield even when the size of single or plural electronic components to be processed is various.

[0005]

Means for Solving the Problems and Effects of the Invention The invention as set forth in claim 1 made in order to achieve the above object, shields electromagnetic waves entering and leaving a single or a plurality of electronic components mounted on a printed circuit board. And a conductive member that is disposed above the electronic component with a gap and has a lower end that is spaced apart upward from the printed circuit board, and between the electronic component and the conductive member. Formation
And a thermal conductive resin layer, and a connecting portion erected between the periphery of the conductive member and the ground electrode of the printed circuit board by solidifying the conductive paste discharged from the dispenser. , The conductive member is
Conductive pace discharged from the spencer onto the surface of the resin layer
Of the resin layer by solidifying the resin
It is characterized in that it is constituted by a net-like shape that covers the parts or parallel lines at equal intervals .

According to the present invention thus constructed, a kind of metal case is constituted by the conductive member and the connecting portion, whereby the electromagnetic waves entering and exiting the electronic component can be favorably shielded. In addition, the connecting portion discharges the conductive paste from the dispenser, and the lower end is bridged between the conductive member arranged above the printed circuit board and the ground electrode of the printed circuit board to solidify the conductive paste. It consists of: Therefore, even after mounting the electronic components on the printed circuit board,
The connection part can be easily constructed. Therefore, according to the present invention, it is possible to easily shield the electromagnetic waves entering and leaving the electronic component even after the electronic component is mounted on the printed circuit board.

Further , in the present invention, since the resin layer having thermal conductivity is formed between the electronic component and the conductive member, the heat generated in the electronic component is transferred to the conductive member through the resin layer. However, heat can be radiated from the conductive member.
Accordingly, in the present invention, in addition to the above effects, effects caused <br/> Ru such overheating of the electronic components can be effectively prevented.

[0008]

Further, in the present invention, not only the connecting portion but also the conductive member is made of a conductive paste discharged from a dispenser. Therefore, the conductive member can be freely and easily formed according to the size of the electronic component (single or plural as described above). Moreover, the conductive member is formed into a mesh or the like by the conductive paste.
Since it is formed in parallel lines at intervals, it has a sufficient electromagnetic wave shielding property.

Therefore, in the present invention, in addition to the above effects,
Even when the size of single or multiple electronic components to be shielded against electromagnetic waves is various, it facilitates the production of conductive members,
There is an effect that the cost required for the electromagnetic wave shield can be satisfactorily reduced.

[0011]

[0012]

[0013]

[0014] The invention of claim 2, wherein, in addition to the configuration of claim 1 Symbol placement, the conductive paste, it at least one of metal particles or carbon fibers is obtained by dispersing the paste as a filler Is characterized by.
When the conductive paste is composed of such a member, extremely good conductivity can be obtained and the manufacturing cost can be reduced. Accordingly, in the present invention, in addition to the effect of the invention of claim 1 Symbol placement, effect occurs such a cost required for the electromagnetic shield with an electromagnetic shielding property is further improved suitably can be better reduced.

[0015] According to a third aspect, the electromagnetic wave entering and leaving the placed on single or plurality of electronic components on a printed circuit board to a electromagnetic shielding method of shielding, the conductive
The surface of the child part is coated with resin and the surface of the resin is
The conductive paste discharged from the pencer is coated in a net shape,
The conductive member is constructed by solidifying the conductive paste
By, at an interval of the conductive member above the electronic components, moreover, the lower end of the conductive member is disposed away upward from the printed circuit board, the ground around and the printed circuit board of the conductive member It is characterized in that a conductive paste is discharged from a dispenser and installed between the electrodes, and the discharged conductive paste is solidified.

According to the present invention, the conductive member is arranged above the electronic component with a space between the electronic member and the lower end of the conductive member so as to be separated upward from the printed circuit board. It is sufficient to discharge the conductive paste from the dispenser by a dispenser to bridge it to the ground electrode, and to solidify it, so that the work is extremely easy. Further, this work can be easily performed even after mounting the electronic component on the printed circuit board. By this work, a kind of metal case is constituted by the conductive member and the solidified metal, and the electromagnetic waves entering and leaving the electronic component can be shielded well. Accordingly, in the electromagnetic shielding method of the present invention, Ru can be easily shielded electromagnetic waves into and out of the electronic component even from after mounting electronic components on a printed circuit board.

[0017]

Further , according to the present invention, since the surface of the electronic component is coated with the resin and the conductive member is formed on the surface, the conductive member can also be composed of the conductive paste discharged from the dispenser. it can. Therefore, the conductive member can be freely and easily formed according to the size of the electronic component (single or plural as described above). Moreover, the conductive member because it is configured in the network form by the above conductive paste <br/>, have sufficient electromagnetic shielding properties.

Therefore, in the present invention, in addition to the above effects,
Even when the size of single or multiple electronic components to be shielded against electromagnetic waves is various, it facilitates the production of conductive members,
There is an effect that the cost required for the electromagnetic wave shield can be satisfactorily reduced.

[0020]

[0021]

[0022]

According to a fourth aspect of the present invention, in addition to the structure of the third aspect , the conductive paste is prepared by dispersing at least one of fine metal particles and carbon fibers in a paste form as a filler. It has a feature. When the conductive paste is composed of such a member, extremely good conductivity can be obtained and the manufacturing cost can be reduced. Therefore, in the present invention, claim 3
In addition to the effects of the described invention, there are effects that the electromagnetic wave shielding property can be further improved and the cost required for the electromagnetic wave shielding can be further reduced.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. First, a description of an embodiment of the present invention will be given.
Stand up and explain a reference example to help understand the embodiment.
Reveal FIG. 1A is a plan view showing a configuration of an electromagnetic wave shield structure 1 as a first reference example , and FIG. 1B is a cross-sectional view taken along the line AA. In each of the following reference examples or embodiments, the case where a single electronic component 97 (IC or the like) mounted on the printed circuit board 99 is shielded by electromagnetic waves will be described as an example. (Eg multiple I's
A substantially similar configuration can be adopted when electromagnetic waves are shielded from a control unit including C, a capacitor, a resistor, etc.).

As shown in FIG. 1, an electromagnetic wave shield structure 1
Then, the resin 80 having the thermal conductivity is disposed in the dispenser 80 (see FIG.
The resin layer 3 is formed by discharging the resin layer 3 onto the surface of the electronic component 97, and a metal paste (dispersed in a paste form using fine metal particles as a filler) is discharged from the dispenser 80 onto the surface of the resin layer 3. Thus, the metal layer 5 as a conductive member is formed. Further, the connection portion 7 is formed between the periphery of the metal layer 5 and the ground electrode (not shown) on the printed circuit board 99 by discharging the metal paste from the dispenser 80 and installing the metal paste. The metal layer 5 and the connection portion 7 thus formed of the metal paste are solidified by leaving them at room temperature to form a metal case that covers the electronic component 97.

In the electromagnetic wave shield structure 1 thus configured, the electromagnetic wave entering and exiting the electronic component 97 can be satisfactorily blocked by the kind of metal case formed by the solidified metal layer 5 and the connecting portion 7. Further, since the resin layer 3 having good thermal conductivity is formed between the metal layer 5 and the electronic component 97, the heat generated in the electronic component 97 is transferred to the metal layer 5 via the resin layer 3. The heat can be radiated from the metal layer 5. Therefore, overheating of the electronic component 97 can be prevented effectively.

Further, in the electromagnetic wave shield structure 1, since the resin layer 3 and the metal layer 5 are formed by the resin or the metal paste discharged from the dispenser 80, they can be freely and easily according to the size of the electronic component 97. Can be formed. Therefore, even when the electronic components 97 to be shielded by electromagnetic waves have various sizes, the cost required for the electromagnetic shielding can be favorably reduced. Further, since the connecting portion 7 is also formed of the metal paste discharged from the dispenser 80, in the electromagnetic wave shield structure 1 of this reference example , the electronic component 97 is mounted on the printed circuit board 99 together with other electronic components or circuits not shown. It can be easily configured later.

Although various nozzles 81 can be used in the dispenser 80, in manufacturing the electromagnetic wave shield structure 1, when the resin layer 3 and the metal layer 5 are formed, as shown in FIG.
The flat nozzle 81a as shown in FIG. 2A is replaced with the thin circular nozzle 8a as shown in FIG.
1b was used respectively. Therefore, in this reference example ,
The resin layer 3 and the metal layer 5 could be formed quickly, and the connection portion 7 could be formed precisely. The nozzle 8
Any one of 1 may be used, or 3 or more may be used.

For example, as in the electromagnetic wave shield structure 11 according to the embodiment of the present invention shown in FIG. 3, the metal layer 15 may be formed in a mesh shape by using only the thin circular nozzle 81b. In this case, although the average discharge speed of the metal paste is reduced, it becomes possible to form the metal layer 15 and the connecting portion 17 by a series of operations without replacing the nozzle, and it is more efficient to adopt this form. There are some cases.
Also, when using only the nozzles 81b, the metal layer may be formed by discharging a metal paste to parallel lines at equal intervals, is better in the case of forming a net like metallic layer 15 Excellent electromagnetic wave shielding effect can be obtained. Further, instead of the resin layer 3, a resin sheet which has been formed into a sheet shape in advance may be used. Furthermore, conductive paste
As an alternative, use carbon fiber instead of the above metal paste.
As paste, dispersed in paste or gold
Fine particles and carbon fibers are used as a filler to form a paste.
You may use what was scattered .

The following description is a reference outside the scope of the present application.
It is explanation about an example. 4 (A) and (B) are the second reference
It is an explanatory view showing a method of manufacturing an electromagnetic wave shielding structure 21 as Reference Example. In this reference example , as shown in FIG. 4 (A), a resin sheet 23 (corresponding to a resin layer) and a metal plate 25 (corresponding to a conductive member) having thermal conductivity capable of being thermally deformed are provided on the electronic component 97. It is sequentially stacked. Then, FIG. 4 (B)
As shown in FIG. 5, the resin sheet 23 is thermally deformed so that the resin sheet 23 surrounds the electronic component 97 from the entire circumference, and a metal paste is discharged from the dispenser 80 onto the surface of the resin sheet 23.
A connecting portion 27 for connecting the ground electrode (not shown) of 9 and the periphery of the metal plate 25 is formed.

Also in this case, as described above, the electromagnetic wave can be shielded easily and satisfactorily even after the electronic component 97 is mounted. In addition, the resin sheet 23 and the metal plate 2
5 can be easily manufactured in various sizes by punching or the like, and the cost required for electromagnetic wave shielding can be satisfactorily reduced even when the electronic components 97 have various sizes. In addition, in the present reference example , the metal plate 25 may be smaller than the package of the electronic component 97. Also,
If a heat-deformable material is used also for the metal plate 25, the metal plate 25 is deformed along the surface of the resin sheet 23 to manufacture an electromagnetic wave shield structure having a cross-sectional shape almost similar to that of FIG. be able to.

FIG. 5 is a sectional view showing the structure of an electromagnetic wave shield structure 31 as a third reference example. In the electromagnetic wave shield structure 31, the resin sheet 3 having the same or slightly narrower thermal conductivity than the electronic component 97 on the surface of the electronic component 97.
3 (corresponding to a resin layer), and a metal plate 35 (corresponding to a conductive member) having an inclined surface 35a inclined toward the printed circuit board 99 on the periphery (the entire circumference or only two opposing sides) may be laminated thereon. ) Are stacked. Then, the connection portion 37 is formed between the lower end of the inclined surface 35a and the ground electrode (not shown) of the printed circuit board 99 by discharging a metal paste from the dispenser 80.

Also in this case, as described above, the electromagnetic wave can be shielded easily and satisfactorily even after the electronic component 97 is mounted. In addition, the resin sheet 33 and the metal plate 3
5 can be easily manufactured in various sizes by punching or the like, and the cost required for electromagnetic wave shielding can be satisfactorily reduced even when the electronic components 97 have various sizes. Further, the lower end of the inclined surface 35a is the printed circuit board
Be slightly lifted from the 9, the metal pastes have some degree of viscosity, the connection by the connecting unit 37 can be performed satisfactorily. Therefore, the electromagnetic wave can be favorably shielded even when the electronic component 97 has various heights. In this reference example , the horizontal portion 35b of the metal plate 35 can be made smaller than the package of the electronic component 97.

Further, a flange portion 36 as shown in FIG. 6 is formed at the lower end of the inclined surface 35a, and the flange portion 36 is
You may provide the hole part 36a as shown in FIG. 6 (A), or the notch part 36b as shown in FIG. 6 (B). In this case, when the flange portion 36 is lifted from the printed board 99, the metal paste can be hung down through the hole portion 36a or the cutout portion 36b, and the connection between the metal plate 35 and the ground electrode of the printed board 99 can be further improved. It will be easier.

FIG. 7 is a sectional view showing the structure of an electromagnetic wave shield structure 41 as a fourth reference example . In this reference example ,
A resin sheet 43 similar to the resin sheet 33 is laminated on the surface of the electronic component 97, and a flat metal plate 45 having no inclined surface is laminated thereon. A hole 45a is formed around the metal plate 45 (may be the entire circumference or only two opposite sides) by punching, and the metal paste discharged from the dispenser 80 is hung down through the hole 45a to form a printed circuit board. A connecting portion 47 is formed to connect the ground electrode 99 (not shown) and the periphery of the metal plate 45.

Also in this case, as described above, the electromagnetic wave can be shielded easily and satisfactorily even after the electronic component 97 is mounted. In addition, the resin sheet 43 and the metal plate 4
5 can be easily manufactured in various sizes by punching or the like, and the cost required for electromagnetic wave shielding can be satisfactorily reduced even when the electronic components 97 have various sizes. Further, in the present reference example , although the space between the periphery of the metal plate 45 and the printed circuit board 99 is widened, the provision of the hole 45a allows the metal paste to hang down through the hole 45a to easily form the connection portion 47. can do.

In order to avoid electrical connection between the lead 97a of the electronic component 97 and the connecting portion 47, the hole 45a is preferably provided outside the position where the lead 97a is provided, as shown in FIG. When the hole 45a is provided on the lead 97a, the resin 48 is provided from the dispenser 80 through the hole 45a as in the electromagnetic wave shield structure 51 shown in FIG.
After discharging, the connecting portion 47 is formed along the surface of the resin 48.
Should be formed. By doing this, lead 97
It is possible to satisfactorily avoid conduction between a and the connecting portion 47. Further, in this case, the metal plate 45 can be downsized to further facilitate the electromagnetic wave shielding after the electronic component 97 is mounted.

The hole 45a may be a series of elongated holes as shown in FIG. 9 (A), or may be a large number of holes arranged in a line as shown in FIG. 9 (B). Good. Furthermore, it is considered that substantially the same effect will be obtained when the notch portion similar to that shown in FIG. 6B is provided instead of the hole portion 45a.

Furthermore, the perspective view of FIG. 10A and FIG.
As shown in a cross-sectional view taken along the line BB of 0 (B), a trough-shaped groove portion 49 may be provided around the metal plate 45, and a hole portion 45a may be provided at the bottom portion of the groove portion 49. In this case, since the metal paste accumulated in the groove 49 smoothly hangs down through the hole 45a, the connection 47 can be formed more easily. Although the groove 49 is provided on the entire circumference of the metal plate 45 in FIG. 10, it may be provided only on two opposite sides.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above embodiments, and various embodiments can be carried out without departing from the gist of the present invention. it is Ru can.

[0041]

[Brief description of drawings]

FIG. 1 is a plan view and a cross-sectional view showing a configuration of a first reference example for understanding the present invention.

FIG. 2 is an explanatory view showing a nozzle of a dispenser used for manufacturing the same.

3 is a plan view showing the configuration of implementation of the embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a manufacturing method of a second reference example .

FIG. 5 is a cross-sectional view showing a configuration of a third reference example .

FIG. 6 is a perspective view showing a modified example of the reference example .

FIG. 7 is a cross-sectional view showing a configuration of a fourth reference example .

FIG. 8 is a cross-sectional view showing a modified example of the reference example .

9 is a perspective view showing a configuration of a hole in the reference example of FIGS. 7 and 8. FIG.

FIG. 10 is a perspective view and a sectional view showing a further modified example of the reference examples of FIGS. 7 and 8.

[Explanation of symbols]

1, 11, 21, 31, 41, 51 ... Electromagnetic wave shield structure 3 ... Resin layer 5, 15 ... Metal layer 7, 17, 2
7, 37, 47 ... Connection portions 23, 33, 43 ... Resin sheet 25, 35, 4
5 ... Metal plates 36a, 45a ... Holes 36b ... Notches
48 ... Resin 49 ... Groove 80 ... Dispenser
81 ... Nozzle 97 ... Electronic component 97a ... Lead
99 ... Printed circuit board

─────────────────────────────────────────────────── --- Continuation of front page (56) Reference JP-A-7-111299 (JP, A) JP-A-10-214923 (JP, A) JP-A-11-258623 (JP, A) JP-A-2001-7233 (JP, A) JP-A-4-192493 (JP, A) JP-A-4-326600 (JP, A) JP-A-10-41678 (JP, A) Actually open 2-42499 (JP, U) (JP, A) 58) Fields surveyed (Int.Cl. ⁷ , DB name) H05K 9/00 H01L 23/28

Claims (4)

(57) [Claims] 1. An electromagnetic wave shield structure for shielding electromagnetic waves entering and exiting a single or a plurality of electronic components mounted on a printed circuit board, the electromagnetic shield structure being disposed above the electronic components with a space therebetween and having a lower end. A conductive member that is arranged apart from the printed circuit board upward, and is formed between the electronic component and the conductive member, and has a thermal conductivity.
Comprising a resin layer having a gender, by solidifying the discharged conductive paste from the dispenser, and a bridging connection portion between the peripheral and the ground electrode of the printed circuit board of said conductive member, said conductive member Is discharged from the dispenser onto the surface of the resin layer.
By solidifying the discharged conductive paste, the above
A net-like or evenly spaced flat surface that at least partially covers the resin layer.
An electromagnetic wave shield structure characterized by being arranged in rows and lines . Wherein said conductive paste, electromagnetic wave shielding structure of claim 1 Symbol mounting, characterized in that at least one of metal particles or carbon fibers is obtained by dispersing the paste as a filler. 3. An electromagnetic wave shielding method for shielding electromagnetic waves entering and leaving a single or a plurality of electronic components mounted on a printed circuit board, the surface of the electronic component being coated with a resin , and the surface of the resin being covered. , The conductive paper discharged from the dispenser
Strike a net to solidify the conductive paste.
By configuring the conductive member by an interval of the conductive member above the electronic components, moreover, the lower end of the conductive member is disposed away upward from the printed circuit board, and the surrounding of the conductive member An electromagnetic wave shielding method, characterized in that a conductive paste is discharged from a dispenser and installed between the ground electrode of the printed board and the discharged conductive paste is solidified. 4. The electromagnetic wave shielding method according to claim 3, wherein as the conductive paste, a paste in which at least one of metal fine particles and carbon fibers is dispersed as a filler is used.