Sun Microsystems, Inc.

Randall C Luckenbihl

Sergiu Radu

Russel K Brovald

An EMI-shielding riser card for reducing electromagnetic radiation from a computer enclosure is disclosed. The EMI-shielding riser card is a six-layer riser card having a connector adjacent its lower edge, such as a connector for an NLX system board. A cable connection socket is on the riser card a first distance away from the connector, and a plurality of traces in a signal layer of the riser card run between the cable connection socket and the connector. A first ground layer in the riser card is interposed between the signal layer and a first surface of the riser card. A second ground layer in the riser card is interposed between the signal layer and a second surface of the riser card. The first and second ground layers are configured to attach to a ground connection for a system board for which the riser card is adapted.

Emi-shielding riser card for a computer chassis

A shielded riser card assembly for reducing electromagnetic radiation from a computer enclosure is disclosed. The riser card assembly comprises a four-layer riser card having a connector adjacent its lower edge, such as a connector for an NLX system board. A cable connection socket is on the riser card a first distance away from the connector, and a plurality of traces on a surface of the riser card run between the cable connection socket and the connector. A sheet of conductive material covers the plurality of traces and is spaced a second distance apart from the surface of the riser card. At least one fastener connected is to the sheet and attached to the riser card. The fastener conductively connects the sheet of conductive material to a ground layer of the riser card. A plurality of non-conductive spacers are disposed between and in contact with both of the sheet and the riser card, for maintaining the sheet a predetermined distance away from the riser card.

Riser card local EMI shield for a computer chassis

A method and apparatus for reducing electromagnetic radiation emanating from a computer enclosure are disclosed, for application to computer enclosure enclosing at least one source of electromagnetic radiation of a computer system, where the enclosure includes an unshielded opening in the computer enclosure through which an undesirable amount of electromagnetic radiation from the source is capable of passing to an exterior of the computer enclosure. The apparatus includes a system board mounted to a frame of the computer enclosure, and a riser card connected to the system board within the computer enclosure. The riser card is a PCB having at least one ground layer and a signal layer, and extends transversely from the system board. The riser card divides an interior space of the computer enclosure into two compartments, a source compartment containing the source of electromagnetic radiation, and an unshielded compartment having the unshielded opening in it. The ground layer of the riser card is positioned towards a side of the riser card facing the unshielded compartment. The apparatus further includes a sheet metal barrier attached to the frame of the computer enclosure and around a perimeter of the ground layer. The riser card and the sheet metal barrier together form an EMI shield between the source compartment and the unshielded compartment, whereby the undesirable amount of electromagnetic radiation from the source is prevented from passing to an exterior of the computer enclosure.

Growing community of inventors

Pleasanton, CA, United States of America

Randall C Luckenbihl