Electromagnetic shielding structure of high-frequency circuit arrangements

• US 5,150,282 A
• Filed: 09/24/1991
• Issued: 09/22/1992
• Est. Priority Date: 12/14/1990
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Takagi, Hisamitsu, Tomura, Masashi
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Ledynh, Bot L.
• Application Number:
  US07/764,724
• Time in Patent Office: 364 Days
• Field of Search: 361/390, 361/391, 361/395, 361/399, 361/422, 361/424, 455/300, 455/301, 174/35 R, 174/35 MS
• US Class Current: 361/818
• CPC Class Codes: H04B 1/3833 Hand-held transceivers
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
• CPC Class Codes: H04M 1/0202 Portable telephone sets, e.g. cordless phones, mobile phones or bar type handsets constructional features of telephone transmitters or receivers, e.g. of speakers or microphones H04M1/03
• CPC Class Codes: H04M 1/0214 Foldable telephones, i.e. with body parts pivoting to an open position around an axis parallel to the plane they define in closed position combined with translation movement H04M1/0235
• CPC Class Codes: H05K 9/0037 Housings with compartments containing a PCB, e.g. partitioning walls

Abstract

An electromagnetic shielding structure of high-frequency circuit arrangements which is capable of electromagnetically shielding each high-frequency functional circuit within a narrow space. A printed-circuit board mounted with a plurality of high-frequency functional circuits is installed in the shielding case. Ribs with a long groove are formed on the inside surface of a molded plastic casing which has been treated to provide electrical conductivity, for separating the high-frequency functional circuits mounted on the printed-circuit board. In the long groove of the ribs is pressed a shielding member, and with the printed-circuit board assembled between the shielding case and the molded plastic casing, the top end of the shielding member is pressed against a ground pattern of the printed-circuit board.

Claims

1. An electromagnetic shielding structure of high-frequency circuit arrangements, comprising:

a mounting member at least the surface of which has been treated to provide electrical conductivity;

a printed-circuit board having a ground pattern installed on said mounting member, said printed-circuit board being mounted with a plurality of high-frequency functional circuits;

a molded plastic casing the inside surface of which has been treated to provide electrical conductivity, for housing said mounting member and said printed-circuit board mounted thereon;

a plurality of ribs formed integral with said inside surface of said molded plastic casing, for separating said high-frequency functional circuits mounted on said printed-circuit board, said ribs having a long groove; and

a shielding member pressed in said long groove of said ribs, said shielding member being a flexible solid material at least the surface of which is electrically conductive, and the top end of said shielding member being pressed against said ground pattern of said printed-circuit board to electromagnetically shield each of said high-frequency functional circuits.

2. The electromagnetic shielding structure of high-frequency circuit arrangements as defined in claim 1, wherein said shielding member is formed of carbon-filled rubber.

3. The electromagnetic shielding structure of high-frequency circuit arrangements as defined in claim 1, wherein said shielding member is formed of rubber laid with a metal foil on the surface.

4. The electromagnetic shielding structure of high-frequency circuit arrangements as defined in claim 3, wherein said metal foil has a stripe-like pattern.