Patent Application
20090073672
1. Field of the Invention
The present invention generally relates to electromagnetic interferences, and particularly to an electromagnetic shield for an electronic device.
2. Description of Related Art
Electronic devices radiate and may also be affected by electromagnetic waves in their surrounding environment. Therefore, electronic devices adopt electromagnetic shields to block electromagnetic waves from radiating out of and into the electronic devices from outside sources. Typically, conductive foam is commonly used as a screen to block the electromagnetic waves.
Referring to
However, a resistivity of the adhesive tape 2 is higher than that of the conductive foam 1, as a result, the electromagnetic shield has poor electrical conductivity. Therefore, the electromagnetic shield has a low efficiency in blocking the electromagnetic energy due to the electrically poor conductivity.
Therefore, improvements for the electromagnetic shield are needed in the industry to address the aforementioned deficiency.
An electromagnetic shield includes a conductive foam, a plurality of adhesive tapes attached to a side of the conductive foam. The adhesive tapes are separated from each other. An electronic device using the electromagnetic shield to block electromagnetic energy from inner component or outer component is also provided.
Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings.
Reference will now be made to the drawings to describe a preferred embodiment of the present electromagnetic shield, and a preferred embodiment of the present electronic device.
Referring to
The conductive foam 10 includes a foam 12 packed in a conductive coat 14. The conductive coat 14 is made of metallic foils, such as aluminum foil, silver foil, and so on. The foam 12 and the conductive coat 14 cooperatively provide flexibility and electrical conductivity.
Each adhesive tape 20 is an electric bond, such as electric glue, including a bond body 22 and metallic grains 24 dispersed in the bond body 22. The bond body 22 is made of adhesive materials such as adhesive resin. The metallic grains 24 are made of silver, copper, etc. When the adhesive tape 20 is pressed, the metallic grains 24 becomes in contact with each other. The electric conductivity of the adhesive tape 20 depends on the metallic grains 24 contacting each other.
Referring to
When the electromagnetic shield 200 is fixed into a position in an electronic device, the adhesive tapes 20 attaches the conductive foam 10 to the position in the electronic device, the conductive foam 10 partially deforms and fills the gaps 30 between the adhesive tapes 20. Thereby, the conductive foam 10 is in direct contact with the position. Therefore, an electric conductivity of the electromagnetic shield 200 is improved, and the electromagnetic shield 200 obtains a comparative shielding efficiency (see
The electromagnetic shield 200 can be widely used in various electronic devices. For example, also referring to
In assembly, the adhesive tapes 20 attaches to the housing 52, and the mainboard 54 is disposed on the conductive foam 10. The screws 56 pass through the mainboard 54 and fasten the mainboard 54 tightly onto the housing 52. In this manner, the conductive foam 10 is pressed by the mainboard 54 toward the housing 52. Consequently, the conductive foam 10 partially deforms and fills the gaps 30 between the adhesive tapes 20. Thereby, the conductive foam 10 is in direct contact with the housing 52. Therefore, static electricity can be conducted from the mainboard 54 to the housing 52, and electromagnetic energy can be blocked from interfering with the circuitry of the mainboard 54.
Furthermore, the notebook computer 50 also includes I/O ports to connect to other peripheral devices, such as keyboards, mice, printers, and so on. Referring to
The I/O port 60 defines a receiving hole therein, and correspondingly the electromagnetic shield 200 also defines a through hole therein. The connector 62 includes a base 622 and a connection portion 620 formed on a side of the base 622. Herein, the connector 62 is shown for illustrative purposes but can also be connected to other peripheral devices, such as printers, scanners, and so on, via an electric wire.
In assembly, the electromagnetic shield 200 is attached to peripheral edges of the I/O port 60. The adhesive tapes 20 attaches to the peripheral edges. The connection portion 620 passes through the through hole of the electromagnetic shield 200, and is received in the receiving hole of the I/O port 60. The base 622 presses the electromagnetic shield 200 toward the I/O port 60. The conductive foam 10 partially deforms and fills the gaps 30 between the adhesive tapes 20, thereby, the conductive foam 10 is in direct contact with the peripheral edges of the I/O port 60. Therefore, the electromagnetic shield 200 can block electromagnetic energy from entering into the notebook computer 50 through the I/O port 60.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200710201710.0 | Sep 2007 | CN | national |
