Embodiments of the present invention generally relate to a separable interface connector, and more particularly relate to a separable interface connector having opposing contacts that reduce lateral forces within the separable connector.
Various electronic systems, such as computers, comprise a wide array of components mounted on printed circuit boards, such as daughterboards and motherboards, which are interconnected to transfer signals and power throughout the system. The transfer of signals and power between the circuit boards requires electrical interconnection between the circuit boards.
Certain interconnections include a socket assembly and a plug assembly. Some socket assemblies include spring contacts, which are configured to mate with conductive pads on the plug assembly. As the socket assembly and plug assembly mate, the spring contacts exert a normal force on the contact pads, thus ensuring proper electrical contact between the spring contacts and the conductive pads.
In order to establish adequate contact, the spring contacts wipe across the conductive pads, cleaning both surfaces, as the plug assembly is mated into the socket assembly. Typically, during mating, the spring contacts are deflected. During deflection, the spring contacts exert a resistive force on the plug assembly. The resistive force typically has normal and tangential components. The normal force is usually referred to as the contact force and the tangential force is usually caused by the frictional behavior of the wiping motion.
As electronic systems become more sophisticated, the systems require an increasing number of spring contacts and equally increasing number of conductive pads. Thus, as electronic systems become more advanced, the quantity of spring contacts within the socket assemblies increase. Conventional socket assemblies align the conductive pads in a desired pattern and orient the spring contacts in the same direction. For example, if one thousand spring contacts are included within a socket assembly all one thousand spring contacts are similarly oriented. Each spring contact includes a wiping portion that extends toward a common side of the socket assembly. As mentioned above, as the plug assembly is mated into the socket assembly, the spring contacts exert a tangential component force on the plug assembly (a component force of the total force, as discussed above). Because all of the spring contacts are oriented in the same direction, the individual tangential component forces exerted by the spring contacts add together. The sum of the tangential component forces may be great enough to cause the plug assembly to shift tangentially while being mated. When the plug assembly shifts, the spring contacts may lose contact with the conductive pads. Even if the spring contacts do not lose complete contact with the conductive pads, the spring contacts may only partially contact the conductive pads which diminishes the reliability of the electrical connection between the spring contacts and the conductive pads.
The socket assembly typically includes an enforced, robust socket frame that is formed of plastic. The socket frame typically must be robust enough to ensure that the plug assembly remains aligned within the socket assembly. That is, the socket frame acts as a barrier that contains the plug assembly. The socket frame typically needs to be strong enough to withstand the sum of the tangential component forces exerted on the plug assembly by the spring contacts. However, as more spring contacts are included within the socket assembly, the sum of the forces exerted by the spring contacts increases. As the sum of the tangential component forces increases, conventional socket frames typically need greater strength to maintain proper alignment between the plug assembly and the socket assembly. Manufacturing socket assemblies with more robust, stronger socket frames typically increases the costs of manufacture and increases the area on the printed circuit board occupied by the connector, which impacts both system cost and electrical performance. Thus, as more spring contacts are used within the socket assembly, manufacturers typically will need to develop stronger, larger and more expensive socket frames.
Thus, a need exists for a more efficient electrical connector that utilizes spring contacts. Further, a need exists for an electrical connector that maintains adequate contact between spring contacts and conductive pads. Additionally, a need exists for a separable interface electrical connector in which a plug assembly remains adequately aligned to a corresponding socket assembly. Moreover, a need exists for a separable interface electrical connector in which the cumulative lateral forces are minimized and/or substantially reduced. Also, a need exists for a more cost-efficient electrical connector.
Certain embodiments of the present invention provide a separable interface electrical connector system. The system comprises a plug assembly and a socket assembly. The plug assembly includes a first conductive pad and a second conductive pad. The socket assembly includes first and second spring contacts, which are configured to contact the first and second conductive pads, respectively, and induce first and second tangential forces thereon. The first and second spring contacts are oriented in directions opposing one another such that upon mating of the plug assembly and the socket assembly, the first tangential component force exerted on the plug assembly by the first spring contact at least partially offsets the second tangential component force exerted on the plug assembly by the second spring contact.
The system may include a plurality of spring contacts arranged in a variety of opposing configurations. The spring contacts may be interleaved such that adjacent spring contacts are oriented in opposing directions. Optionally, the spring contacts may be arranged in sets, such that one set of spring contacts are oriented in a direction that opposes the orientation of another set.
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings.
Each spring contact 16 or 17 includes a wiping tip 20. As discussed below with respect to
Each spring contact 16 and 17 is formed of a conductive material. For example, each spring contact 16 and 17 may be formed of gold-plated nickel. Also, each spring contact 16 and 17 may have a certain elasticity that allows it to deflect upon mating of the plug assembly and the socket assembly 10.
Because there is a growing normal force between the tip of the springs and the conductive pad during the deflection of the spring, the spring contacts 16 exert a frictional force on the plug assembly 28 in the direction of line B. As shown in
As the plug assembly 28 is mated into the socket assembly 10 in the direction of line A, the spring contacts 16 and 17 exert a normal component force on the plug assembly 28 in the direction of line C. However, the spring contacts 16 and 17 also exert tangential component forces in opposite directions on the plug assembly 28. That is, the spring contacts 16 exert a tangential component force in a direction that is opposite to the tangential component force exerted by the spring contacts 17.
As the set of spring contacts 16 wipe in the direction of line B, the spring contacts 16 exert a tangential component force on the plug assembly 28 in the direction of line B. Also, as the set of spring contacts 17 wipe in the direction of line F, the spring contacts 17 exert a tangential component force on the plug assembly 28 in the direction of line F. Because the spring contacts 16 and 17 are formed of the same material and have the same structural behavior, the normal force exerted by a spring contact 16 is equal, or substantially equal, to the normal force exerted by a spring contact 17. However, the tangential force exerted by the spring contact 16 is equal to, but opposite that exerted by the spring contact 17. Hence, the tangential component forces (denoted by line B) exerted by the spring contacts 16 offset, reduce, cancel, or at least substantially minimize, the tangential component forces (denoted by line F) exerted by the spring contacts 17. The sum of the tangential component forces within the separable interface electrical connector is approximately zero. However, the sum of the forces does not have to be zero. Rather, the sum of the forces may be a value that is small enough to ensure adequate alignment between the socket and plug assemblies.
For example, if the proper alignment between the spring contacts 16, 17 and corresponding conductive pads 30 may be maintained with a tangential force less than or equal to a certain number of Newtons (kg(m)/s2), pounds, etc., in the direction of lines B or F, then the spring contacts 16 and 17 may be configured on the socket assembly 10 in a way that limits the sum of the tangential forces to less than or equal to the permissible force. In other words, the number of spring contacts 16 does not necessarily have to equal the number of spring contacts 17. Rather, the number of spring contacts 16 and 17 may be dictated by an acceptable limit of the vector sum of the tangential forces within the separable interface electrical connector. For example, in a one thousand contact socket assembly 10, adequate alignment between the wiping tips 20 of the spring contacts 16, 17 and corresponding conductive pads 30 on the plug assembly 28 may be achieved through four hundred spring contacts 16 and six hundred spring contacts 17. While the sum of the tangential forces exerted by the spring contacts 16 and 17 may not be zero, the sum of the forces may be within tolerable levels to assure adequate alignment between the spring contacts 16, 17 and the corresponding conductive pads 30.
The tangential component forces exerted by the spring contacts 32 in the direction of line G are reduced, cancelled, or substantially diminished by the tangential component forces exerted by the spring contacts 36 in the direction of line I (and vice versa). Similarly, the tangential component forces exerted by the spring contacts 34 in the direction of line H are cancelled, or substantially diminished by the tangential component forces exerted by the spring contacts 38 in the direction of line J (and vice versa).
As mentioned above, the sum of the forces within the separable interface electrical connector formed by the mating of the plug assembly 28 into the socket assembly 10 do not necessarily have to equal zero. Rather, the vector sum of the forces may be a value that allows for adequate alignment between spring contacts and corresponding conductive pads. Further, the number of spring contacts within a set of commonly oriented spring contacts does not have to equal the number of spring contacts in the opposing set of spring contacts.
Hence, the spring contacts 32, 34, 36 and 38 are divided into four sets that are oriented with wiping tips 20 facing inward toward a focal point 35. Optionally, the spring contacts 32, 34, 36 and 38 may be oriented in an opposite direction with wiping tips 20 facing away from focal point 35. As a further alternative, spring contacts 32, 34, 36 and 38 may be oriented in other directions so long as the tangential component forces are substantially offset or minimized by one another. As yet a further alternative, individual contact springs or interleaved rows of contact springs may be oriented in opposite directions to form offsetting tangential component forces.
The opposed spring contacts may be used in a Land Grid Array (LGA) connector. However, embodiments of the present invention may be used with any type of separable interface connector that utilizes spring contacts. Further embodiments of the invention may be used with any type of electrical connector in which control of lateral shifting or moving components within the electrical connector is necessary.
Also, while
Embodiments of the present invention may be used with traditional stamped and molded plug and socket assemblies. The socket assembly and plug assembly may be shaped differently than the embodiments shown. For example, the socket assembly may be a circular socket assembly with the spring contacts positioned such that each wiping contact extends towards the center of the circular socket assembly.
Thus, embodiments of the present invention provide a separable interface electrical connector that maintains adequate alignment between spring contacts and conductive pads. Also, embodiments of the present invention provide a separable interface electrical connector in which a plug assembly remains adequately aligned with a corresponding socket assembly. Further, embodiments of the present invention provide a more cost-efficient electrical connector because less material, or less robust material, is needed to ensure that the plug assembly remains properly aligned with the socket assembly.
While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
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Number | Date | Country | |
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20040077202 A1 | Apr 2004 | US |