Patent Application
20130157499
1. Field of the Invention
The present invention generally relates to electrical connectors, and more particularly to a thermal interface for cooling electrical connectors.
2. Background of the Related Art
A data cable is an electronic cable having electrically conductive signal lines that provide an electronic data pathway between two devices. A data cable commonly has a connector on at least one end for removably connecting to a corresponding connector on one device. The other end of the data cable is either hard-wired to the other device or has another connector for removably connecting to the other device. Many standard connector types are used in data cables, examples of which include Universal Serial Bus (USB), Digital Video Interface (DVI), and High-Definition Multimedia Interface (HDMI). Cables that passively carry signals on conductive pathways commonly degrade the data being transmitted, due to channel impairment phenomena such as attenuation, crosstalk and group velocity distortion. These inherent limitations of common conductive materials limit the length and performance of passive data cables.
Active cables have been developed that include an embedded semiconductor chip in the connector body to boost the signal performance. The chip includes embedded active circuitry that boosts and clarifies the signal being transmitted. Active cables can use copper signal lines or an optical medium, such as glass fibers, to carry data. The active circuitry can decrease the amount of copper required relative to passive copper data cables. The optical fibers used in active optical cables have much lower transmission losses than metal wires. As a result, both copper and optical active cables can be made thinner, longer, or faster than a passive version of the cable. Some commercially available active cables, for example, can be more than five times as long. However, the active circuitry in the connector body consumes electricity and generates heat. In some active cables, a heat sink is therefore provided to dissipate the heat generated by the active circuitry. The heatsink is typically inside the computer system or hardware device that the cable plugs into, so that the system can cool the cable via the heat sink.
A disclosed active electrical connection system includes separable first and second connectors. The first connector includes a plug, and the second connector includes a socket configured for receiving the plug to a connected position within the socket. Active signal processing circuitry is provided, in electronic communication with one or both of the first and second connectors, for processing a data signal transmitted between the first and second connector. A heat sink includes a heat sink base secured to the second connector. The heat sink base is positioned for sliding engagement with the plug at a mechanical interface between the base and the plug as the plug is moved to the connected position within the socket. A plurality of corresponding protrusions and recesses are provided at the mechanical interface between the base and the plug. These include, at least, protrusions on one of the heat sink base and the plug and recesses on the other of the base and the plug. The protrusions are vertically misaligned with the corresponding recesses upon entry of the plug into the socket to urge the heat sink away from the plug. The recesses are vertically aligned with the protrusions to receive the protrusions when the plug reaches the connected position.
An active electrical connection system is disclosed that includes a heatsink positioning system responsive to the connection and disconnection between first and second connectors. The active electrical connection system also provides an improved mechanical and thermal interface between the heatsink and one of the first and second connectors. The first connector may be a plug, and the second connector may be a socket for receiving the plug. The active electrical connection system may be used, for example, in the context of connecting an active data cable to a computer system or hardware device, where the first connector is on the active data cable and the second connector is on the computer system chassis or hardware device chassis.
In a disclosed example embodiment, the first connector includes a plug on an active data cable and the second connector includes a socket for releasably receiving the plug. The heatsink is movably supported on the second connector. As further detailed below, a heatsink positioning system comprises a plurality of protrusions provided on one (or both) of the plug and the heat sink base, that cooperate with corresponding recesses on the other of the plug and the heat sink base, to precisely position the heat sink base relative to the plug as the plug is moved within the socket. The protrusions on the plug and/or heat sink base are located so that they will cause the heat sink base to move upward slightly upon insertion of the plug, against the force provided by a biasing member, such as one or more spring fingers. The protrusions will maintain the raised position of the heat sink base until the plug reaches the connected position within the socket, at which point the protrusions vertically align with corresponding recesses. When the protrusions vertically align with the corresponding recesses, the protrusions are received into the corresponding recesses as the heat sink base is urged by the spring fingers into thermal engagement with the plug. This precise positioning of the heat sink prevents shearing forces that can damage a thermal interface material applied to a mechanical interface between the heat sink base and the plug.
A heat-generating component is provided in the first connector. In this example embodiment, the heat-generating component comprises active circuitry included within the active electrical connection system to control a data signal, such as to boost and clarify a data signal being transmitted across the connection between the first and second connectors 20, 60. The active circuitry may include circuit elements on one or both of the first and second connectors 20, 60. The active circuitry may include a microcontroller chip 29 which performs signal processing, such as to amplify, filter, or otherwise clarify the transmitted signal. The chip 29 is typically in the body of the first connector 20, as it is in this embodiment, although elements of a heat-generating component may also be located on the second connector 60 or within the distal end of the plug 24 that is received within the socket 64.
The active circuitry generates heat, which may be due to active signal processing on the chip 29, increased current flow through the first and second connectors 20, 60 from the boosted signal, from, or a combination thereof. A heat sink 80 is mounted on the second connector 60 for dissipating the heat generated by the active electrical connection system 10. When the plug 24 is connected within the socket 64, the base 84 of the heat sink 80 thermally engages the plug 24 to conduct heat away from the plug 24. The heat sink 80 includes a plurality of heat sink fins 82 coupled to the heat sink base 84. The fins 82 conduct heat away from the base 84 and collectively provide a large amount of surface area exposed to open air for convective cooling of the active electrical connection system 10. For example, the heat sink 80 may be located within a chassis having forced air flow that passes across the heat sink fins 82.
The protrusions 26 on the plug 24 are near a leading end 30 of the plug 24 that is first to enter the socket 64. Prior to reaching the fully connected position, the protrusions 26 on the plug 24 are vertically misaligned with the recesses 86 on the base 84, and the recesses 28 on the plug 24 are vertically misaligned with the protrusions 88 on the base 84. Thus, as the plug 24 is inserted, the protrusions 26 initially contact the lower surface 85 of the base 84, urging the base 84 slightly upward. As the plug 24 is moved further inside the socket 64, the protrusions 26 slide along the lower surface 85 of the base 84. Because the protrusions 26 on the plug 24 are at a wider pitch P2 than the protrusions 88 on the base 84, the protrusions 26 on the plug 24 are allowed to slide past the protrusions 88 on the base 84, without interference. Just as the plug 24 reaches the connected position, the protrusions 26 on the plug 24 become vertically aligned with the corresponding recesses 86 on the base 84. Simultaneously, the recesses 28 on the plug 24 become vertically aligned with the protrusions 88 on the base 84. This vertical alignment of protrusions and corresponding recesses allows the base 84 to be urged by the biasing member into thermal engagement with the upper surface 25 of the plug 24.
The cable 12 includes any number of signal lines 14, which may comprise copper wires or optical fiber, for example. The signal lines may extend along the cable 12, through the connector housing 22 and plug 24, and typically terminate to one or more card 42 which has the active circuitry components 29 on it. In this embodiment, the plug contacts 43 provided by the cards 42 (shown on both sides of each card) are positioned to automatically engage the socket contacts provided by the leaf spring fingers 44 in response the plug having been moved to the connected position within the socket. Alternatively, a zero insertion force embodiment may allow for a separate, moveable engagement and disengagement between plug and socket contacts while the plug and socket remain stationary in the connected position.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but it is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
