Shielded enclosure for housing electronic components and manufacturing method thereof

• US 5,473,111 A
• Filed: 09/14/1993
• Issued: 12/05/1995
• Est. Priority Date: 10/07/1992
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hattori, Yoshiyuki, Hatayoshi, Mutuo
• Primary Examiner(s): Nimmo, Morris H.
• Assistant Examiner(s): Horgan, Christopher
• Application Number:
  US08/120,468
• Time in Patent Office: 812 Days
• Field of Search: 174/35 R, 174/35 GC, 174/35 MS, 361/816, 361/818, 250/505.1, 250/515.1, 455/300, 455/301, 29/527.4
• US Class Current: 174/363
• CPC Class Codes: B29C 45/1418 the inserts being deformed or preformed, e.g. by the injection pressure
• CPC Class Codes: B29C 45/14795 Porous or permeable material, e.g. foam
• CPC Class Codes: B29C 70/885 with incorporated metallic wires, nets, films or plates as lost heating elements B29C35/0272, B29C61/0625
• CPC Class Codes: B29K 2105/206 Meshes, lattices or nets
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: B29K 2995/0011 Electromagnetic wave shielding material
• CPC Class Codes: B29L 2031/7162 Boxes, cartons, cases
• CPC Class Codes: H05K 9/0045 being rigid plastic containers having a coating of shielding material
• CPC Class Codes: H05K 9/0047 being rigid plastic containers having conductive particles, fibres or mesh embedded therein
• CPC Class Codes: H05K 9/0084 comprising a single continuous metallic layer on an electrically insulating supporting structure, e.g. metal foil, film, plating coating, electro-deposition, vapour-deposition
• CPC Class Codes: Y10T 29/49986 Subsequent to metal working

Abstract

An EMI protected enclosure and method of manufacture thereof. The enclosure is plastic and has an electromagnetic interference shield member disposed therein to protect the electronic parts or electronic equipment from electromagnetic interference. The electromagnetic interference shield member is exposed at the edges of the enclosure and can be formed into an electrical connector or otherwise connected to provide a ground for the enclosure. In the manufacturing method, the securing and shaping of the electromagnetic interference shield member by the closure of the molding dies eliminates the need for any pre-forming of the electromagnetic interference shield member.

Claims

1. An EMI shielded structure for housing electronic parts or equipment comprising:

an enclosure comprising a substantially planar plate area having a first edge and at least one side wall extending substantially orthogonally to said plate area from said first edge;

said enclosure having a second edge forming an outer edge of said enclosure, said enclosure being made substantially of a molded resin;

an electromagnetic interference shield member comprising at least one of a thin, flexible wire netting or a metal foil having a plurality of small holes;

said electromagnetic interference shield member being disposed within said enclosure resin;

said electromagnetic interference shield member being slanted at said second edge of said at least one side wall of said enclosure;

said slanted portion of said electromagnetic interference shield beginning at an inner edge formed from the intersection of said side wall and said plate area of said enclosure; and

said slanted portion of said electromagnetic interference shield member extending from and being exposed at said second edge of said side wall of said enclosure.

2. The structure as defined in claim 1, wherein said exposed shield member portion comprises an electrical contact.

3. The structure as defined in claim 1, wherein said enclosure comprises an air vent connecting the interior and exterior portions of said structure, said air vent having no resin material but comprising said electromagnetic interference shield member only.

4. The structure as defined in claim 1, wherein said side wall is substantially orthogonal to said plate area.

5. A method of manufacturing an enclosure for housing electronic parts or equipment, consisting of a box or a cover having a planar surface and sides with an exposed side edge and being molded by resin, using a fixed and a moveable die, comprising the steps of:

setting a pre-cut, planar plate-shaped electromagnetic interference shield member in a position to face said fixed die, said electromagnetic interference shield member being made of a thin, flexible wire netting or a metal foil having a plurality of small holes disposed on substantially all surfaces of said enclosure, and having an area large enough to leave an excess amount of member exposed from the edges of the enclosure after the molding of the enclosure;

shaping said electromagnetic interference shield member while closing said movable die in the direction of said fixed die;

injecting a molding resin material into a space formed by said fixed die and said movable die after the start of said die closing to cause part of said molding resin material to penetrate toward said movable die through the holes of said electromagnetic interference shield member;

moving said movable die to a final die closing position for pressing said electromagnetic interference shield member and resin material into the desired shape of said enclosure while leaving an excess amount of shield member at said exposed edge or said enclosure; and

curing said shaped enclosure.

6. The method of manufacturing an EMI protected enclosure as defined in claim 5, further comprising forming an electrical contact from said excess member at said enclosure edge.

7. A method of manufacturing an EMI protected enclosure consisting of a box or a cover molded by resin for housing electronic parts or equipment, comprising the steps of:

setting a pre-cut, planar plate-shaped electromagnetic interference shield member in a position to face a fixed die, said electromagnetic interference shield member being made of a thin, flexible wire netting or a metal foil having a plurality of small holes, being disposed on substantially all surfaces of said enclosure, and having an area large enough to be exposed from the edges of the enclosure after the molding of the enclosure;

shaping and securing said electromagnetic interference shield member by closing said movable die in the direction of said fixed die;

injecting a molding resin material into a molding space formed by said fixed die and said movable die after said shaping and securing by the die closing, a portion of said material being injected through said secured shield member to completely fill said molding space; and

curing said molded resin material.

8. The method of manufacturing an EMI protected enclosure as defined in claim 7, further comprising forming an electrical contact from said excess member at said enclosure edge.

9. A method of manufacturing an EMI protected enclosure consisting of a box or a cover molded by resin for housing electronic parts or equipment, an electromagnetic interference shield member existing inside the resin, wherein said electromagnetic interference shield member is made of a thin, flexible wire netting or a metal foil having a plurality of small holes, comprising:

setting said shield member between moveable and fixed parts of a mold die, in a pre-cut, planar plate-shaped state;

at least partially shaping said member by said movable die and a fixed die by closing said mold die; and

injecting a curable plastic material into said mold die through and around said shield member.

10. A method of manufacturing an EMI protected enclosure for housing electronic parts or equipment, consisting of a box or a cover made of resin and containing within the resin an electromagnetic interference shield member and being molded by using a core die and a cavity die each of which has a respective outer periphery and which together define a mold volume having the shape of said enclosure, comprising the steps of:

setting a pre-cut, planar plate-shaped electromagnetic interference shield member in a position between said core die and said cavity die, said member having an area large enough to be exposed from the edges of the enclosure after the molding of the enclosure; and

closing said core are and cavity die whereby said electromagnetic interference shield member extends out of a gap between the outer periphery of said cavity die and the outer periphery of said core die to the outside of said mold volume.

11. An enclosure consisting of a box or a cover molded by resin for housing electronic parts or equipment, an electromagnetic interference shield member being disposed inside the resin, wherein said electromagnetic interference shield member is exposed from the intersection points of the side wall outside of said enclosure and the edges of said enclosure.

12. The structure as defined in claim 11, wherein said exposed shield member portion comprises an electrical contact.