U.S. patent application number 12/493250 was filed with the patent office on 2009-10-29 for electromagnetic shielding device.
This patent application is currently assigned to ASUSTEK COMPUTER INC.. Invention is credited to Min-Che Kao.
Application Number | 20090266603 12/493250 |
Document ID | / |
Family ID | 38711782 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090266603 |
Kind Code |
A1 |
Kao; Min-Che |
October 29, 2009 |
ELECTROMAGNETIC SHIELDING DEVICE
Abstract
An electromagnetic shielding device suitable for a PCB includes
a cover and a conductive rubber frame. The cover is made of a
conductive material and has a through hole and a containing space.
The conductive rubber frame is contacted with the through hole of
the cover. The conductive rubber frame contacts with the PCB and is
electrically connected to the ground end. The electronic component
is enclosed by the cover and the conductive rubber frame.
Inventors: |
Kao; Min-Che; (Taipei,
TW) |
Correspondence
Address: |
JIANQ CHYUN INTELLECTUAL PROPERTY OFFICE
7 FLOOR-1, NO. 100, ROOSEVELT ROAD, SECTION 2
TAIPEI
100
TW
|
Assignee: |
ASUSTEK COMPUTER INC.
Taipei
TW
|
Family ID: |
38711782 |
Appl. No.: |
12/493250 |
Filed: |
June 29, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11743160 |
May 2, 2007 |
7570495 |
|
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12493250 |
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Current U.S.
Class: |
174/377 |
Current CPC
Class: |
H05K 9/0015 20130101;
H05K 9/0032 20130101 |
Class at
Publication: |
174/377 |
International
Class: |
H05K 9/00 20060101
H05K009/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 19, 2006 |
TW |
95117814 |
Claims
1. An electromagnetic shielding device, suitable for a PCB
comprising an electronic component disposed thereon and a ground
end, the electromagnetic shielding comprising: a cover made of a
conductive material, the cover having a through hole and a
containing space; and a conductive rubber frame contacted with the
through hole of the cover, wherein the conductive rubber frame
contacts with the PCB and is electrically connected to the ground
end, and the electronic component is enclosed by the cover and the
conductive rubber frame.
2. The electromagnetic shielding device as recited in claim 1,
wherein the conductive material is metal.
3. The electromagnetic shielding device as recited in claim 1,
wherein the cover comprises a cover plate and a side wall joining
the cover plate, while the through hole is formed in the side
wall.
4. The electromagnetic shielding device as recited in claim 3,
wherein the conductive rubber frame comprises: a sheath portion,
enclosing the side wall; and at least a plug portion, located in
the through hole, wherein both ends of the plug portion join with
the sheath portion.
5. The electromagnetic shielding device as recited in claim 1,
wherein the conductive rubber frame comprises at least a
positioning portion extending towards the PCB, the PCB has a
positioning hole corresponding to the positioning portion, the
positioning portion is disposed in the positioning hole, so as to
position the cover and the conductive rubber frame on the PCB.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of and claims the
priority of patent application Ser. No. 11/743,160, filed on May 2,
2007, which claims the priority benefit of Taiwan patent
application serial no. 95117814, filed on May 19, 2006. The
entirety of each of the above-mentioned patent applications is
hereby incorporated by reference herein and made a part of this
specification.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to an electromagnetic
shielding device, and more particularly to an electromagnetic
shielding device using conductive rubber as the frame thereof.
[0004] 2. Description of the Related Art
[0005] One of common problems with an electronic equipment is
electromagnetic interference (EMI). A running circuit usually emits
electromagnetic radiation, which affects the transmission signals
and electric performances of other electronic components. A mobile
phone, for example, has a strict requirement on anti
electromagnetic interference (anti-EMI), due to a quite fast
transmission speed the mobile phone's signal has. Therefore, in
general, a mobile phone is always equipped with an electromagnetic
shielding device on the printed circuit board (PCB) thereof to
prevent the electromagnetic radiation from leakage or to avoid an
induced in leakage of external electromagnetic radiations, which
causes unwanted interferences.
[0006] FIG. 1A is a cubic exploded drawing of a conventional
electromagnetic shielding device. FIG. 1B is a cubic drawing of the
electromagnetic shielding device in FIG. 1A after assembling.
Referring to FIGS. 1A and 1B, a conventional electromagnetic
shielding device 100 is made of metal material and includes a
metallic frame 110 and a metallic cover 120. The metallic frame 110
is fixed on a PCB 130 by using surface mount technology (SMT) and
has multiple protrusion portions 112 on the outer surface 110a
thereof. The metallic cover 120 has a cover plate 122 and a side
wall 124, which joins the periphery region of the cover plate 122
has multiple through holes 126 corresponding to the above-mentioned
protrusion portions 112.
[0007] To assemble the metallic cover 120 onto the metallic frame
110, the inner surface of the side wall 124 of the metallic cover
120 is fit on with the outer surface 110a of the metallic frame
110, followed by buckling the protrusion portions 112 on the
metallic frame 110 in the corresponding through holes 126 of the
metallic cover 120, so as to reliably assemble the metallic cover
120 with the metallic frame 110.
[0008] Since the metallic cover 120 and the metallic frame 110 are
closely interconnected by means of the above-described approach,
the metallic cover 120 is unlikely separated from the metallic
frame 110. In turn, the metallic cover 120 is accordingly hard to
be disassembled from the metallic frame 110 when the electronic
components on the PCB 130 need to be maintained. As a usual
maintain manner today, some hand tools, such as tweezers, are used
to prize the side wall 124 of the metallic cover 120, followed by
removing the metallic cover 120 from the metallic frame 110.
However, during removing the metallic cover 120 from the metallic
frame 110, the side wall 124 of the metallic cover 120 are likely
deformed and then the metallic cover 120 is hard to keep its
original shape for using repeatedly. Besides, during disassembling
the metallic cover 120, the integrity of the outer surface 110a of
the metallic frame 110 is further destroyed. For a metallic frame
110 fixed on the PCB 130 by using surface mount technology (SMT),
an accidental operation mistake resulting in integrity loss of the
metallic frame 110 may further cause assembly troubles after
maintaining.
[0009] On the other hand, it needs to take account of material cost
issue. For a usual electromagnetic shielding device today, the
cover and the frame thereof are made of metal. To get better metal
conductive efficiency, copper is a preferred choice for the cover
and the frame. However, in recent years, the prices of metal
material together with most of crude material, particularly the
price of copper, has been soaring continuously, which further
increases the production cost of an electromagnetic shielding
device to impressive extent.
SUMMARY OF THE INVENTION
[0010] An objective of the present invention is to provide an
electromagnetic shielding device, which uses conductive rubber to
fabricate the frame thereof, so as to solve the problem of hard
disassembly caused by a conventional metallic frame and occurred
during maintaining.
[0011] To achieve the above-described or other objectives, an
embodiment of the present invention provides an electromagnetic
shielding device suitable for a PCB. The electromagnetic shielding
device includes a cover and a conductive rubber frame. The cover is
made of a conductive material and has a through hole and a
containing space. The conductive rubber frame is contacted with the
through hole of the cover. The conductive rubber frame contacts
with the PCB and is electrically connected to the ground end. The
electronic component is enclosed by the cover and the conductive
rubber frame.
[0012] In an embodiment of the present invention, the
above-described conductive material is metal.
[0013] In an embodiment of the present invention, the cover
includes a cover plate and a side wall joining the cover plate, and
at least a through hole is disposed in the side wall.
[0014] In an embodiment of the present invention, the
above-described conductive rubber frame includes a sheath portion
and at least a plug portion. The sheath portion encloses the side
wall; the plug portion is located in the through hole, while both
ends of the plug portion join the sheath portion enclosing the side
wall.
[0015] In an embodiment of the present invention, the
above-described conductive rubber frame further includes at least a
positioning portion, which extends towards the PCB. The PCB has at
least a positioning hole corresponding to the positioning portion,
and the positioning portion resides in the positioning hole, so as
to position the cover and the conductive rubber frame on the
PCB.
[0016] The electromagnetic shielding device of the present
invention mainly includes a cover and a conductive rubber frame
enclosing the cover. The conductive rubber frame can be directly
fabricated on the cover by using a buried injection process, which
effectively reduces the component number of the electromagnetic
shielding device and simplifies the mounting process flow thereof.
Besides, due to the elasticity the conductive rubber material
possesses, the problems of disassembly difficulty and low
repeatable usage caused by the prior art where the cover and the
frame of a conventional electromagnetic shielding device are made
of metal can be solved. Furthermore, due to the low costs of the
conductive rubber material and the die development, an entire
electromagnetic shielding device is expectedly produced in a
cost-effective way.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve for explaining the principles of the invention.
[0018] FIG. 1A is a cubic exploded drawing of a conventional
electromagnetic shielding device.
[0019] FIG. 1B is a cubic drawing of the electromagnetic shielding
device in FIG. 1A after assembling.
[0020] FIG. 2A is a cubic exploded drawing of an electromagnetic
shielding device according to an embodiment of the present
invention.
[0021] FIG. 2B is a cubic drawing of the electromagnetic shielding
device in FIG. 2A after assembling.
[0022] FIG. 3 is a cross-sectional view of the electromagnetic
shielding device in FIG. 2B across the sectioning plane I-I'.
DESCRIPTION OF THE EMBODIMENTS
[0023] FIG. 2A is a cubic exploded drawing of an electromagnetic
shielding device according to an embodiment of the present
invention; FIG. 2B is a cubic drawing of the electromagnetic
shielding device in FIG. 2A after assembling. Referring to FIGS. 2A
and 2B, an electromagnetic shielding device 200 mainly includes a
cover 220 and a conductive rubber frame 240, wherein the cover 220
is made of metal, while the conductive rubber frame 240 is made of
conductive rubber. The electromagnetic shielding device 200 is
disposed on a PCB 210 to enclose the electronic component disposed
on the PCB 210 (not shown). By means of the electromagnetic
shielding device 200, the electronic component on the PCB 210 is
isolated from an external electromagnetic interference (EMI), and
the leakage of the electromagnetic radiation generated from the
electronic component is prevented as well.
[0024] FIG. 3 is a cross-sectional view of the electromagnetic
shielding device in FIG. 2B across the sectioning plane I-I'.
Referring to FIGS. 2A and 3, the cover 220 includes a cover plate
222 and a side wall 224 joining the periphery region of the cover
plate 222, where the side wall 224 extends towards the PCB 210. The
side wall 224 has an inner surface 226, an outer surface 228
opposite to the inner surface 226, multiple through holes 230 and a
bottom surface 232. The through hole 230 can be long-round hole as
shown in FIG. 2A or other shape holes, such as round hole, square
hole or rectangular hole.
[0025] Referring to FIG. 3, the conductive rubber frame 240 takes a
frame shape and closely encloses the inner surface 226, outer
surface 228 and bottom surface 232 of the side wall 224. The
through hole 230 is filled with a part of the conductive rubber
frame 240 to affix the conductive rubber frame 240 on the side wall
224 of the cover 220. As shown in FIG. 3, the conductive rubber
frame 240 further includes a sheath portion 242, multiple plug
portions 244 and multiple positioning portions 246, wherein the
sheath portion 242 has a bottom portion 248. The sheath portion 242
encloses the inner surface 226, the outer surface 228 and the
periphery region of the bottom surface 232 of the side wall 224 of
the cover 220. The plug portions 244 are disposed corresponding to
the through holes 230 of the side wall 224 and placed in the
through holes 230, respectively. Both ends of the plug portion 244
respectively join two parts of the sheath portion 242, where the
two parts enclose the inner surface 226 and the outer surface 228
of the side wall 224, respectively. In this way, the conductive
rubber frame 240 is reliably fixed on the side wall 224 of the
cover 220 not to worry about separating from the cover 220. The
present invention does not limit the numbers and places of the
through holes 230 and the plug portions 244. In addition, the
bottom portion 248 of the conductive rubber frame 240 can be
optionally served for disposing multiple positioning portions 246
on it for the positioning purpose, wherein the positioning portions
246 extend towards the PCB 210.
[0026] After combining the cover 220 with the conductive rubber
frame 240 to form the electromagnetic shielding device 200, the
positioning portions 246 of the conductive rubber frame 240 is
inserted into the corresponding positioning holes 216 on the PCB
210. An enclosed space between the electromagnetic shielding device
200 and the PCB 210 is formed, as shown in FIG. 2B and the enclosed
space encloses the electronic component disposed on the PCB 210. By
means of some parts over the electromagnetic shielding device 200,
the position of the electromagnetic shielding device 200 is
restricted, and the electromagnetic shielding device 200 is
accordingly not separated from the PCB 210. Continuing to FIG. 3,
since the conductive rubber frame 240 closely encloses the side
wall 224 of the cover 220, the conductive rubber frame 240 and the
cover 220 are electrically connected to each other. The
electromagnetic wave absorbed by the cover 220 of the
electromagnetic shielding device 200 can be induced to the ground
end of the PCB 210 via the conductive rubber frame 240, so that the
electronic component disposed on the PCB 210 is protected from
EMI.
[0027] The method for fabricating the above-described
electromagnetic shielding device 200 is described as follows.
First, a sheet of metal is cut out to have an outline required by
the cover 220, followed by punching to complete the through holes
230. Next, the side wall 224 is completed by press forming. After
that, a conductive rubber material is used to conduct a buried
injection process, where a conductive rubber frame 240 is formed on
the side wall 224 of the cover 220. The conductive rubber frame 240
encloses the inner surface 226, the outer surface 228 and the
bottom surface 232 of the side wall 224. A part of the conductive
rubber frame 240 (i.e. the plug portions 244) fills in the through
holes 230, so as to affix the conductive rubber frame 240 on the
side wall 224 of the cover 220. Thus, the entire process for
fabricating the electromagnetic shielding device 200 is
finished.
[0028] In summary, the conductive rubber frame of the embodiment is
directly fabricated on the side wall of the metallic cover by
conducting a buried injection process. Therefore, the
electromagnetic shielding device of the present invention is
designed with `one-body forming`. In comparison with the
conventional design where the metallic cover and the metallic frame
of an electromagnetic shielding device are designed as two
independent components, the electromagnetic shielding device design
of the present invention can effectively reduce the number of the
employed components and simplify the mounting process flow
thereof.
[0029] Furthermore, instead of the prior art where a SMT process is
used to affix an electromagnetic shielding device onto a PCB, the
present invention uses the positioning portions of the
electromagnetic shielding device to be inserted into the
positioning holes on the PCB and restricts the electromagnetic
shielding device position by means of other components, so as to
reliably affix the electromagnetic shielding device onto the PCB.
Therefore, in comparison with the prior art, the present invention
has advantages of, not only a convenience to disassemble the
electromagnetic shielding device from the PCB 210 during
maintaining, but also avoiding the cover or the frame structure
from damage, which effectively advances the repeat usage of the
electromagnetic shielding device 200. Without a hand tool to
disassemble the cover also avoids an accidental operation mistake,
which eliminates the possibility of the frame damage and easies the
assembly and disassembly of the cover and the frame.
[0030] In terms of production cost, since the conductive rubber
material and the die-making cost are cheaper than the metallic
material, the present invention further effectively lowers the
fabrication cost of an entire electromagnetic shielding device.
[0031] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
specification and examples to be considered as exemplary only, with
a true scope and spirit of the invention being indicated by the
following claims and their equivalents.
* * * * *