MXPA99009013A - A shielding housing and a method of producing a shielding housing - Google Patents

Abstract

A shielding housing (11) for electrically shielding at least one component on a printed circuit board (12), comprises a layer (14) of a non-shielding material having at least one cavity (15) for receiving said at least one component. An elastic gasket (16) is provided on the rim of said at least one cavity (15). A layer (17) of an electrically shielding material covers the gasket (16) as well as one or both surfaces of said layer (14) of a non-shielding material. In operation, the shielding housing (11) is pressed with its gasket (16) against a conductor (13) located on the printed circuit board (12) around said at least one component to be shielded.

Description

A PROTECTIVE ACCOMMODATION AND A METHOD TO PRODUCE A PROTECTIVE ACCOMMODATION TECHNICAL FIELD The invention relates to a protective housing for electrically protecting one or more components of a printed circuit board as well as to a method for producing said protective housing.

BACKGROUND OF THE INVENTION To prevent electronic components, eg, mobile phones, from transmitting unwanted signals of high frequency that may interfere with other electronic equipment or vice versa, that is, prevent other electronic equipment from interfering With components in mobile phones, these components have to be electrically protected. Additionally, this protection is necessary in order for the equipment to comply with the electronic compatibility (EMC) requirements. Currently, boats or welded housings are used to protect critical components on a printed circuit board. Protection cans are soldered to conductors on the printed circuit board to cover critical components. - However, it is often necessary to test the components placed under the protection boats. These tests have to be carried out both during the production stages and in services after the sale. Protective boats welded to printed circuit boards are difficult to remove and replace in connection those tests and services.

COMPENDIUM OF THE INVENTION The object of the invention is to provide a protective housing that is easy to assemble and disassemble, and that is economical to produce and economical to replace. This is achieved in that the protective housing according to the invention is made of a non-protective, inexpensive material, or of a semiprotector / semiconductor material; e.g., a plastic material, with or without conductive fillers such as graphite and metal fibers, and has at least one cavity to receive the components to be protected. Along the rim of the cavity, an elastic packing is provided. The packing as well as the internal and / or external surface of the housing are covered by an electrically protective material, e.g., a conductive paint, a metallization or a thin sheet of metal. The protective housing according to the invention is intended to be pressed, that is, not welded, with its packing against a conductor that is provided around the components that are to be protected. By means of the present, the protection housing will be easy to assemble and disassemble. Since the protective housing according to the invention is made of economical material, it is economical to produce.

BRIEF DESCRIPTION OF THE DRAWING The invention will be described in more detail below with reference to the accompanying drawing, in which Figures 1-5 are cross-sectional, schematic views of five different embodiments of a protection housing according to the invention.

PREFERRED MODALITIES It should be noted that, in order to better illustrate the invention, the dimensions of the layers and other elements of the different modalities shown in Figures 1-5 are greatly exaggerated. In the drawing, Figure 1 shows a first embodiment of a protection housing according to the invention, generally denoted 11, for 'protecting one or more components (not shown) on a printed circuit board 12. In the printed circuit board, in a manner known per se, a conductor 13 surrounds the components to be protected by means of the protection housing 11. The housing 11 as shown in the drawing comprises a layer 14 of a non-protective, economical material, e.g., a plastic material, which is somewhat stiff. In the embodiment according to Figure 1, the layer 14 is formed to define a single cavity 15 for receiving the components (not shown) to be protected in the board 12. Along the rim of the housing 11, ie, along the rim of the cavity 15 in the embodiment shown, an elastic packing 16 has been deposited. The package 16 can be made of any suitable non-conductive, semi-conductor / semi-conductor or conductive elastic material, eg, plastic material such as silicone, silicone rubber, epoxy, polyurethane or thermoplastic elastomers. The package 16 can be deposited in the rim of the cavity 15 eg by injection molding, gumming, assortment or any other appropriate process. According to the invention, in the embodiment shown, the package 16 and the inner surface of the layer 14, that is to say the inside of the cavity 15, are covered by a layer 17 of an electrically insulating material, e.g. a conductive paint, a metallization or a thin sheet of metal. Instead of welding to the conductor 13 on the printed circuit board 12, according to the invention, the housing 11 is supposed to be pressed with its packing 16 against the conductor 13 by means of v.gr ,, at least one screw ( not shown) or at least one staple (not shown). In. In the case of a mobile telephone, the housing 11 can be pressed against the printed circuit board by means, eg, of a cover cap (not shown) of the mobile telephone. Figure 2 shows a second embodiment of a protection housing 21 according to the invention. As in the embodiment of Figure 1, the housing 21 according to Figure 2 comprises a layer 24 of a non-protective, economical material, which is formed to define a single cavity 25 for receiving the components (not shown) that are going away to protect on the printed circuit board (not shown in Figure 2), Along the rim of the housing 21, ie, along the rim of the cavity 25 in the embodiment shown, an elastic package 26 has been deposited . The embodiment according to Figure 2 differs from the embodiment according to Figure 1 simply in that the gasket 26 and the outer surface of the layer 24, that is, the outside of the cavity 25 instead of its interior, are covered by a layer 27 of an electrically protective material of the same type as in Figure 1. It should be understood that, from a production point of view, it may be convenient, in a non-illustrated manner, to cover both the interior and the exterior. outside of a housing in accordance with Figures 1 and 2, as well as packaging with a layer of an electrically protective material. Figure 3 illustrates a third embodiment of a protection housing 31 in accordance with the invention. The protection housing 31 resembles the protection housing 11 in Figure 1, but is provided with two cavities 35 for protecting two different sets of components (not shown) on the printed circuit board 32. The cavities 35 are separated by an elastic partition wall 38 formed from the same material and in the same process as the gaskets 36 along the outer rim of the housing 31, ie, along the rim of a layer 34 of a non-protective, economic material. in the embodiment according to Figure 3, a layer 37 of a protective material is deposited on the package 36, inside the housing "31, and on the sides and the lower flange of the dividing wall 38. As a consequence, the printed circuit board 32 has been provided with conductors 33 which cooperate not only with the package 36 but also with the lower flange of the dividing wall 38. Figure 4 illustrates a fourth embodiment of a protective housing 41 in accordance with the invention. The embodiment in Figure 4 resembles the embodiment of Figure 2, but in accordance with the invention, the housing 41 is provided with a guide pin 48 which is adapted to cooperate with a corresponding hole 49 in a board 42 of circuit housing 41. Figure 5 is a fifth embodiment of a protective housing 51 in accordance with the invention. The embodiment in Figure 5 resembles the embodiment in Figure 4. The only difference between these embodiments is that a layer 57 of protective material covers a package 56 on the rim of the housing 51 as well as both, the interior and the exterior of the housing 51 and all of a guide pin 58 cooperating with a corresponding hole 59 in a printed circuit board 52. As in the other embodiments, it is assumed that the housing 51 is pressed with its packing 56 against a conductor 53 on the printed circuit board 52. In this way, since the protective housing according to the invention is not intended to be welded to a printed circuit board, it will be easy to separate in order to test the components that are placed under it, after said test, It will be equally easy to put the protective housing back in its place. By using economical material, the protective housing according to the invention will also be economical to produce. In case the protective housing has to be replaced, said replacement consequently will not involve any high costs.

Claims (3)

1. - A protective housing for electrically protecting at least one component in a printed circuit board, comprising a layer of a non-protective material having at least one cavity to receive the at least one component, the rim of the at least one cavity being provided with a socket of an elastic material, characterized in that a continuous layer of u? electrically protective material covers the packaging and one or both surfaces of the layer of a non-protective material, the protective housing being intended to be prd with its packing, covered by the layer of an electrically protective material, against a conductor placed on the board of printed circuit, around which at least one component will be protected.

2. A method for producing a protective housing for electrically protecting at least one component in a printed circuit board, comprising forming at least one cavity in a layer of a non-protective material to receive the at least one component, and arranging a packing of an elastic material on the flange of the at least one cavity, characterized by depositing a continuous layer of an electrically protective material in the package, and one or both surfaces of the layer of a non-protective material, the protective housing being intended to be prd with its package covered by the layer of an electrically protective material, against a conductor on the printed circuit board, surrounding the at least one component to be protected.

3. The use in a mobile telephone of a protective housing in the form of a layer of a non-protective material, having at least one cavity, a packing of an elastic material in the rim of the at least one cavity, and a continuous layer of an electrically protective material that covers the cap and one or both surfaces of the layer of a non-protective material. SUMMARY OF THE INVENTION A protective housing (11) for electrically protecting at least one component in a printed circuit board (12), comprises a layer (14) of a non-protective material having at least one cavity (15) for receiving the at least one component . An elastic package (16) is provided in the flange of. the at least one cavity (15). A layer (17) of an electrically protruding material covers the package (16) as well as one or both surfaces of the layer (14) of a non-protective material. In operation, the protective housing (11) is prd with its packing (16) against a conductor (13) placed on the printed circuit board (12) around the at least one component to be protected. FIG.5