V-seal EMC gasket assembly for precise placement, conduction and retention without adhesives

A V-seal EMC gasket assembly is provided for implementing precise placement, conduction and retention, while eliminating the need for adhesives. A V-seal EMC gasket and a supporting member include cooperating notch and protrusion features for positioning and retaining the V-seal EMC gasket on the supporting member. A distal end of the V-seal EMC gasket is received and retained within angled stops formed in the supporting member. A retaining clip member holds the V-seal EMC gasket in contact engagement with the supporting member. The protrusion features of the supporting member are received through corresponding mating slots formed near a first end of the retaining clip member, for example, in press-fit engagement. The angle stops formed in the supporting member hold a second end of the retaining clip member with the V-seal EMC gasket clamped and retained in position between the supporting member and the retaining clip member.

FIELD OF THE INVENTION

The present invention relates generally to the field of electromagnetic compatibility (EMC) shielding, and more particularly, relates to an enhanced V-seal EMC gasket assembly for precise placement, conduction and retention without adhesives.

DESCRIPTION OF THE RELATED ART

As silicon technologies move toward smaller transistor sizes with smaller feature sizes, packaging densities increase, and operating frequencies increase, the need to contain or minimize electromagnetic interference (EMI) increases.

Electromagnetic compatibility (EMC) requires shielding to contain or minimize electromagnetic interference emissions from an electronic circuit packaging design. Gaskets often are used to fill and electronically bond and seal leaky apertures between mating panel member parts in order to maintain a minimum shielding effectiveness over a defined frequency spectrum. A V type seal EMC gasket or V-seal EMC gasket is used in some designs to meet EMC shielding requirements.

The V-seal EMC gasket is used for EMC containment because it is often the most appropriate and lowest cost gasket for a particular application. A problem with V-seal EMC gaskets is that with mechanical forces in the shear direction it is possible to pull or tear the gasket from its mounting when contacting the sliding surfaces. The V-seal EMC gasket can be slid or even pulled off when exposed to shear forces on the gasket.

Shear forces on the V-seal EMC gasket usually occur during installation assembly, and during removal of the covers, and moving the V-seal EMC gasket allows EMI emissions to escape from the enclosure. When the gasket is slid, the adhesive, either conductive or non-conductive, is smeared across the surface of the mechanical component.

In the case of non-conductive adhesive sliding the V-seal EMC gasket typically lowers the integrity of the connection of the gasket to the metallic surface, as optimal contact is not ensured. If the gasket is ripped or torn from its proper position, shielding integrity typically would be compromised.

Another concern with the use of the V-seal EMC gasket is that exact gasket placement at the time of assembly is required since a pressure sensitive adhesive is used without a guiding fixture, and can facilitate poor alignment.

A need exists for an effective mechanism for enabling precise placement, conduction, and retention of a V-seal EMC gasket without requiring adhesives.

SUMMARY OF THE INVENTION

A principal aspect of the present invention is to provide an enhanced V-seal EMC gasket assembly for implementing precise placement, conduction and retention without adhesives. Other important aspects of the present invention are to provide such enhanced V-seal EMC gasket assembly substantially without negative effect and that overcome many of the disadvantages of prior art arrangements.

In brief, an enhanced V-seal EMC gasket assembly is provided for implementing precise placement, conduction and retention, while eliminating the need for adhesives. A V-seal EMC gasket and a supporting member include cooperating notch and protrusion features for positioning and retaining the V-seal EMC gasket on the supporting member. A distal end of the V-seal EMC gasket is received and retained within angled stops formed in the supporting member. A retaining clip member holds the V-seal EMC gasket in contact engagement with the supporting member. The protrusion features of the supporting member are received through corresponding mating slots formed near a first end of the retaining clip member, for example, in press-fit engagement. The angle stops formed in the supporting member hold a second end of the retaining clip member with the V-seal EMC gasket clamped between the supporting member and the retaining clip member and retained in position.

In accordance with features of the invention, the supporting member is formed of an electrically conductive material. The supporting member is a metal member, for example, formed of sheet metal.

In accordance with features of the invention, the protrusion features for positioning and retaining the V-seal EMC gasket on the supporting member are relatively small angled tabs and cause a minimal impedance change on the supporting member. The V-seal EMC gasket is formed of a rigid material having sufficient strength and electromagnetic compatibility properties, such as a selected one of beryllium copper and stainless steel.

In accordance with features of the invention, the retaining clip member is formed of either an electrically nonconductive or electrically conductive material, for example, a plastic material or a metal material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Having reference now to the drawings, inFIG. 1, there is shown an enhanced V-seal EMC gasket assembly for implementing precise placement, conduction and retention generally designated by the reference character100in accordance with the preferred embodiment. V-seal EMC gasket assembly100includes a V-seal EMC gasket102, a supporting member or chassis104of the preferred embodiment, and at least one retaining clip member or sheet106of the preferred embodiment.

In accordance with features of the invention, the enhanced V-seal EMC gasket assembly100enables precise placement, conduction and retention, while eliminating the need for adhesives. The V-seal EMC gasket102can be easily removed, for example for recycling, without any additional steps to remove remnants of an adhesive-type gasket as required by conventional V-seal EMC gasket arrangements.

In the V-seal EMC gasket assembly100, the V-seal EMC gasket102and the supporting member104include a plurality of respective cooperating notches108and respective cooperating protrusion features110for positioning and retaining the V-seal EMC gasket102on the supporting member104. A distal end112of the V-seal EMC gasket102is received and retained within a plurality of angled stops114formed in the supporting member104.

The flat or non-flat retaining clip member106holds the V-seal EMC gasket102in contact engagement with the supporting member104and in slight compression. The protrusion features110of the supporting member are received through corresponding mating slots116formed near a first end118of the retaining clip member106, for example, in press-fit engagement. The angled stops114formed in the supporting member104hold a second end120of the retaining clip member106with the V-seal EMC gasket102clamped and retained in position between the supporting member104and the retaining clip member106.

The supporting member104is formed of an electrically conductive material. The supporting member104is a metal member, for example, formed of sheet metal. The protrusion features110for positioning and retaining the V-seal EMC gasket102on the supporting member104are relatively small angled tabs that cause a minimal impedance change on the supporting member.

V-seal EMC gasket102is formed of a rigid or compliant material having sufficient strength and electromagnetic compatibility properties, such as a selected one of beryllium copper and stainless steel or conductively coated foam. The retaining clip member106is formed of either an electrically nonconductive or electrically conductive material, for example, a plastic material or a metal material.

The protrusion features110and the angled stops114are integrally formed from the supporting member104. For example, the protrusion features110and the angled stops114are punched and formed from the supporting member104.

The normally shaped V-seal EMC gasket102is tightly held against the metallic surface104by the retaining clip member106. The retaining clip member106can be implemented with a flat or non-flat thin plastic or metallic plate. The retaining clip member106is placed on an inside surface122of the V-seal EMC gasket102. The metallic supporting surface104is in direct contact with a fabric over foam (FOF) bottom side124of the V-seal EMC gasket102without adhesive. If an adhesive is used between the plastic retaining clip member106and the V-seal EMC gasket102, the adhesive would not be a problem since the adhesive would not be in a conduction path. The retaining clip member106includes an outwardly extending or protrusion portion126extending past the angled stops114.

V-seal EMC gasket102is slit to form the cooperating notches108for receiving the protrusion features110. The protrusion features110are small angled bends that go through the cooperating notches108in the V-seal gasket102and through the corresponding mating slots118in retaining clip member106inside the V-seal gasket. The flexibility or compliance of the V-seal EMC gasket102is not adversely affected by the addition of the retaining clip member106.

The small bends defining protrusion features110hold the V-seal EMC gasket102in place with regard to shear forces and are not large enough to cause any significant impedance change on the metallic supporting surface104. The rear angles114hold the edge120of the plastic retaining clip member106down onto the metallic supporting surface104and allows the V-seal EMC gasket102to align and clip into place.

The V-seal EMC gasket102gasket is removed easily, for example for recycling by slightly pushing in or pulling up on the protrusion portion126of the plastic retaining clip member106that extends past or behind the back angled stops114.