JPH04273200A - Shield device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shielding device applied to electronic equipment to prevent electromagnetic interference.

0003

[Prior Art] For example, in electronic equipment in which an oscillation circuit is constructed on a printed wiring board, it is necessary to prevent the influence of external electromagnetic induction on the oscillation circuit or the influence of this oscillation circuit on the outside. , a shielding device is applied.

FIG. 4 conceptually shows an electronic device to which this type of shielding device is applied.
, 1... are mounted on the upper surface 2a of the printed wiring board 2. A metal shield case 3 is provided on the upper surface 2a of the printed wiring board 2.

[0005] The shield case 3 has a box shape with one side open, and is attached to the upper surface 2a of the printed wiring board 2 via its flange portion 3a. By surrounding the upper area and the four side areas, electromagnetic interference is prevented.

[0006]

[Problems to be Solved by the Invention] However, when the shield case 3 as described above is applied, there is a risk of an electrical short circuit due to contact with the electronic circuit components 1, 1, etc. A required distance must be secured in advance between the electronic circuit components 1, 1, . . . and the shield case 3, which leads to an increase in the size of the electronic device.

Moreover, the shield case 3 needs to have sufficient strength, that is, a sufficient thickness, so as not to be easily deformed even when an external force is applied thereto, which results in an increase in the weight of the electronic device.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, an object of the present invention is to provide a shield device that can reduce the size and weight of equipment.

[Configuration of the invention]

0010

[Means for Solving the Problems] A shield device according to the present invention includes a thin metal film disposed to surround an electronic component mounted on a printed wiring board, and a portion of the thin metal film that corresponds to the electronic component. and an insulating resin film disposed on.

[0011]

According to the above structure, the metal thin film prevents electromagnetic interference, and the insulating resin film prevents electrical short circuits between the metal thin film and electronic components.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below based on drawings showing embodiments. FIG. 1 conceptually shows the main parts of an electronic device to which a shielding device according to the present invention is applied.
A film carrier 20 is disposed on the upper surface 11a of a printed wiring board 11 on which electronic circuit components (electronic components) 10, 10, . . . are mounted, so as to surround the first electronic circuit components 10, 10, .

The film carrier 20 includes a rectangular copper foil (metal thin film) 21 having a thickness of about 35 μm, and a rectangular copper foil (metal thin film) 21 having a thickness of about 75 μm bonded to the center part of the back surface 21a of the copper foil 21 with an epoxy adhesive 22. A rectangular polyimide resin film (insulating resin film) 23 having a thickness is formed in a three-layered form, and the polyimide resin film 23 is arranged to face the first electronic circuit components 10, 10... , the above copper foil 2
It is connected to the ground line 12 of the printed wiring board 11 via connection terminal parts 21b, 21b, . . . formed on the peripheral edge of the printed wiring board 11.

As shown in FIG. 2, this film carrier 20 has a shield portion 20', A large number of shield parts 20' are formed at equal intervals, and by outer lead bonding of these shield parts 20', the printed wiring board 1
It is mounted on the upper surface 11a of 1. At this time, the polyimide resins 23, 23, etc. of the respective peripheral edges of the shield parts 20', 20', . . . , corresponding to the connection terminal parts 21b, 21b, . At the same time as punching from the film carrier tape 24 using a mold (not shown), electrical connection with the ground line 12 of the printed wiring board 11 is made using a bonding tool (not shown). be exposed.

Note that the reference numeral 25 in the figure is a sprocket hole used when feeding the film carrier tape 24 frame by frame.

In the electronic device configured as described above, the first electronic circuit components 10, 10, . . .
Since the first electronic circuit component 10 is surrounded by
, 10 . . . or the influence of the first electronic circuit components 10 , 10 . . . on the outside is prevented as much as possible.

Moreover, since an insulating polyimide resin film 22 is interposed in the portion of the copper foil 21 facing the first electronic circuit components 10, 10..., the copper foil 21 is Even if the circuit components 10, 10, . . . come in contact with each other, an electrical short circuit will not occur.

Therefore, the first electronic circuit component 1
0, 10... can be made as narrow as possible, and the copper foil 21 can be made as thin as possible, making it possible to reduce the size and weight of electronic equipment. becomes.

FIGS. 3(a) and 3(b) conceptually show modified examples of electronic equipment to which the shielding device according to the present invention is applied, respectively, and are similar to the electronic equipment of the embodiment shown in FIG. In this case, the mounting efficiency of electronic components is further improved. Note that the same components as those in the embodiment shown in FIG. 1 are given the same reference numerals, and the description thereof will be omitted.

That is, in the first modification shown in FIG. 3(a), a flexible printed wiring board 30 is disposed on the upper surface 11a of the printed wiring board 11 in such a manner as to surround the film carrier 20.

The flexible printed wiring board 30 has a second electronic circuit component 31 configuring an electronic circuit different from the first electronic circuit component 10 mounted on its upper surface 30a, and an adhesive 32 on its lower surface 30b. is adhered to the upper surface 21c of the copper foil 21 in the film carrier 20, and is connected to the wiring pattern 13 of the printed wiring board 11 via the electrode portions 30c, 30c, . . . .

Furthermore, in a second modification shown in FIG. 3(b), a flexible printed wiring board 40 is disposed within an area surrounded by the film carrier 20 on the upper surface 11a of the printed wiring board 11. .

The flexible wiring board 40 has a lower surface 40
A third electronic circuit component 41 constituting an electronic circuit different from the first electronic circuit components 10, 10, . 23, and its electrode portions 40c, 40c...
It is connected to the wiring pattern 13 of the printed wiring board 11 via. In addition, in the modification shown in FIG. 3(b), it is necessary that the third electronic circuit component 41 does not mutually influence the first electronic circuit component 10, 10, . . . .

In the electronic devices shown in the first and second modifications, the electronic components 31 are also located in the mounting area of the first electronic circuit components 10, 10, . . . on the printed wiring board 11.
, 41, the implementation efficiency can be improved.

In the above embodiments and modifications, the electronic components 10, 31, 41 mounted on the printed wiring board 11 are surrounded by the film carrier 20 formed from the film carrier tape 24. The invention does not necessarily require the use of the film carrier 20. Moreover, although the copper foil 21 is exemplified as the metal thin film and the polyimide resin film 23 is exemplified as the insulating resin film, it is of course possible to employ metal thin films and insulating resin films made of other materials. Furthermore, the metal thin film 21 and the insulating resin film 23 are bonded together using an epoxy adhesive 22.
However, it is not necessarily necessary to use an epoxy adhesive, and the metal thin film and the insulating resin film may be directly bonded together. Furthermore, in both the first and second modified examples, the second and third electronic circuit components 31, 41 are mounted on the flexible printed wiring boards 30, 40, but other printed wiring boards are used. Alternatively, it may be mounted directly on the film carrier. In addition, a second
And when mounting the third electronic circuit components 31, 41, the printed wiring boards 30, 40 and the film carrier 20
Although adhesives 32, 42 are interposed between the two, these adhesives 32, 42 are not necessarily required.

[0026]

As explained above, according to the shielding device according to the present invention, the metal thin film prevents electromagnetic interference, and the insulating resin film prevents electrical short circuits between the metal thin film and electronic components. Therefore, it is possible to reduce the size and weight of the equipment.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view conceptually showing the main parts of an electronic device to which a shielding device according to the present invention is applied.

[Fig. 2] Fig. 2 conceptually shows a shield member applied to the shield device of the present invention, Fig. 2(a) is a plan view, and Fig. 2(b) is a B in Fig. 2(a). - B line sectional view,
FIG. 2(c) is an overall perspective view.

3(a) and 3(b) are cross-sectional side views of main parts conceptually showing modified examples of electronic equipment to which the shielding device according to the present invention is applied, respectively.

FIG. 4 is a cross-sectional side view conceptually showing the main parts of an electronic device to which a conventional shielding device is applied.

[Explanation of symbols]

10　　　　Electronic parts 11 Printed wiring board 21 Metal thin film 23 Insulating resin film

Claims (1)

[Claims] 1. A metal thin film disposed to surround an electronic component mounted on a printed wiring board, and an insulating resin film disposed at a portion of the metal thin film corresponding to the electronic component. A shield device characterized by: