Electrical connectors provide signal connections between electronic devices using signal contacts. Often, undesirable interference, or crosstalk, exists between neighboring signal contacts. A common approach to reducing crosstalk includes interspersing ground contacts among the signal contacts. However, at certain frequencies, signals may tend to “jump” through or across ground contacts, which may contribute to mistransmission and signal errors that are detrimental to the operation of the circuits and the connector.
Frequency domain techniques may be helpful to measure and evaluate the signal loss and crosstalk characteristics of a connector system over a range of frequencies. Viewing crosstalk in the frequency domain shows the measure of crosstalk energy on individual frequencies of interest, e.g., the data rate and significant harmonics. It should be understood that spikes in frequency domain crosstalk are undesirable, as the spikes may indicate spurious voltages between grounds at particular frequencies.
One known approach for addressing such spikes is to fabricate connector leadframe housings from a carbon-impregnated plastic. Though such connectors are advertised to have low frequency domain crosstalk, even in a data-transfer-rate range of about 10-20 Gigabits/sec, the use of carbon-impregnated plastic makes such connectors relatively expensive. It would be desirable, therefore, if there were low-cost solutions that address the problem of spikes in frequency domain crosstalk.
A connector interface may include an arrangement of blade-shaped contacts on a header connector, and a corresponding, complementary arrangement of receptacle contacts on a receptacle connector mating with the blades. The contacts may be positioned in the connectors in an arrangement of signal contacts and ground contacts. For example, a linear array of contacts may be arranged with a signal-ground-signal-ground arrangement, a signal-signal-ground arrangement, or a signal-signal-ground-ground arrangement. The contacts in each linear array may be positioned edge-to-edge and housed in a respective leadframe assembly. Each contact may be positioned broadside-to-broadside with a corresponding contact in an adjacent leadframe assembly. It should be understood, however, that the contacts within a leadframe assembly may be positioned broadside-to-broadside with each other, and positioned edge-to-edge with corresponding contacts in an adjacent leadframe assembly.
When the connectors are mated, a ground may be established between the connectors due to the mating of ground contacts from the respective connectors. Intermittent ground planes may be established at the contact mating surfaces where the broadsides of the receptacle ground contacts engage the broadsides of the header ground blades. Further, the receptacle ground contacts may be shaped to bridge together an array of header ground blades when the connectors are mated. Such bridging tends to establish a continuous ground along the array of mated ground contacts, thereby creating a more robust ground than in an otherwise identical connector. The continuous ground established along the array of mated ground contacts may extend along a direction that is perpendicular to the direction in which the contacts are arrayed in the leadframe assemblies.
In such a connector, frequency domain crosstalk tends to be lower than in an otherwise identical connector without such a continuous ground. Thus, spikes in the frequency domain crosstalk of a connector may be reduced by employing the bridging techniques disclosed herein. Also, electrical properties of a connector, such as signal integrity, for example, may be improved by establishing such a continuous ground.
The first connector 102 and the second connector 104 are shown as vertical connectors. That is, the first connector 102 and the second connector 104 each define mating planes that are generally parallel to their respective mounting planes. The embodiments depicted herein show the first connector 102 as a receptacle connector and the second connector 104 as a header connector. It should be understood that either the first or second electrical connectors 102, 104 could be a header connector or a receptacle connector, and both of the first and second electrical connectors 102, 104 can be right-angle or mezzanine connectors.
The header connector 104 may include a connector housing 106 and electrical contacts 110 extending therethrough. The electrical contacts 110 may be arranged in an arrays in the header connector 104. Each contact 110 may have a cross-section that defines two opposing edges and two opposing broadsides. For example, the contacts 110 may be positioned broadside-to-broadside in a linear array along a first direction 114 and edge-to-edge in a linear array in a second direction that is perpendicular to the first direction 114.
The header connector 104 may include a plurality of insert molded leadframe assemblies (IMLAs) 108 positioned adjacent to one another in the header connector housing 106. Each IMLA 108 may include a leadframe housing 112 through which the contacts 110 at least partially extend. The leadframe housing 112 may be made of a dielectric material, such as plastic, for example. The electrical contacts 110 may be housed in each IMLA 108 in a linear array that extends in the first direction 114 or in the second direction that is perpendicular to the first direction. In
Each of the contacts 110 in the header connector may have a respective mating portion 118 and a respective mounting portion 120. The mounting portions 120 may be suitable for any surface-mount or through-mount application. The mounting portions 120 may be compliant tail ends, or they may include fusible mounting elements, such as solder balls. The mounting portions 120 of the contacts may form a ball grid array (BGA) and electrically connect with apertures on a substrate face. The mating portion 118 of each electrical contact 110 may be blade-shaped and may mate with a respective electrical contact (e.g., 122, 124) of the receptacle connector 102.
The receptacle connector 102 may each include a connector housing 116 and electrical contacts 126 extending therethrough. The electrical contacts 126 may be of varying shapes and sizes, as shown by example contacts 122 and 124. The electrical contacts 126 may be arranged in arrays in the receptacle connector 102. Each contact 126 may have a cross-section that defines two opposing edges and two opposing broadsides. For example, like contacts 110, contacts 126 may be positioned broadside-to-broadside in a linear array along a first direction 114 and edge-to-edge in a linear array in a second direction that is perpendicular to the first direction 114.
The receptacle connector 102 may include a plurality of insert molded leadframe assemblies (IMLAs) 128 positioned adjacent to one another in the receptacle connector housing 116. Each IMLA 128 may include a leadframe housing 130 through which the contacts 126 at least partially extend. The leadframe housing 130 may be made of a dielectric material, such as plastic, for example. The electrical contacts 126 may be housed in each IMLA 108 in a linear array that extends in the first direction 114 or second direction that is perpendicular to the first direction. In
Each of the contacts 126 in the receptacle connector may have a respective mating portion 132 and a respective mounting portion 134. The mounting portions 134 may be suitable for any surface-mount or through-mount application. The mountings portions 134 may be compliant tail ends, or they may include fusible mounting elements, such as solder balls. The mounting portions 134 of the contacts may form a ball grid array (BGA) and electrically connect with apertures on a substrate face.
The mating portion 132 of each of the receptacle contacts 126 may be any shape that may receive or otherwise engage with a complementary contact, such as the contacts 110 of the header connector 104. For example, the mating portion 132 of a receptacle contact 122 may include a receptacle for receiving a male contact.
Upon insertion of the header contact 110, the opposing tines 210, 212 of the receptacle contact 206 may be separated such that a portion of the tines 210a, 212a, of adjacent contacts 206 make contact with each other. The mating receptacle and header contacts, 206, 110, may be ground contacts. Thus, the connection between a tine of a receptacle contact 206 with the tine of an adjacent receptacle contact, with header contacts 110 having a good electrical connection with the adjacent receptacle contacts, may establish a ground between the electrical contacts 122, 110.
The receptacle contact 204 may be configured to make contact with more than one electrical contact 110 in the header connector 102. The first portion 216 may make a point of contact with a header contact 110 and the second portion 218 may make another point of contact with an adjacent header contact 110. In
The receptacle contacts 124 may serve as bridging elements to bridge header contacts. For example, each of the receptacle contacts 124 may have a resilient mating portion 132 that is adapted to bridge together the array of ground contacts from the header connector. As the receptacle contacts 124 mate with adjacent header contacts 110, the receptacle contacts 124 may make points of contact with adjacent header contacts. Each receptacle contact 124 may make contact with more than one header contact 110. For example, the receptacle mating portions 132 may be generally S-shaped with a first curved portion 218 that makes a single point of contact 306 with a first header contact 110, and a second curved portion 216 that simultaneously makes a single point of contact 308 with a second header contact 110 that is adjacent to the first header contact 110. Thus, the receptacle contact 124 interconnects the first and second header contacts 110.
The mating portion 132 of the receptacle contact may have a variety of shapes and sizes. For example, the first curved portion 218 shown has a smaller radius of curvature than the radius of curvature of the second curved portion 216 shown. Upon insertion of a receptacle contact 124 between two adjacent header contacts 110, the first curved portion 218 may make an initial contact 306 with a first header contact 110. As the receptacle contact 124 is inserted further, the second curved portion 216 may make contact 308 with an adjacent, second header contact 110.
The receptacle contacts 124 may bridge together an array of header contacts 110. Each header contact 110 may be housed in a respective leadframe assembly. Thus, the receptacle contacts 124 may bridge together header contacts 110 across a plurality of leadframe assemblies. The receptacle contacts 124 and the header contacts 110 may be ground contacts. A common ground may be established between the header contacts 110 in the first direction, and the common ground may be established across contacts 110 housed in a plurality of leadframe assemblies. Such bridging establishes a common ground along the array of header contacts 110, which tends to reduce time domain frequency crosstalk.
The distance D between the header ground contacts 110 may be smaller than the width W of an unmated receptacle contact 124, as shown in
The receptacle contacts and header contacts are not limited to the sizes and shapes described herein. For example, the receptacle contact may be of any shape suitable for establishing a ground along a linear array of ground contacts.
In
The receptacle connector 402 may contain an array of electrically conductive contacts 404 that define a mating region. The electrical contacts 404 may be housed in insert molded leadframe assemblies (IMLAs) 408. Each IMLA 406 may include a leadframe housing 408 through which the contacts 404 at least partially extend. The leadframe housing 408 may be made of a dielectric material, such as plastic, for example. The IMLAs may be positioned adjacent to each other in a linear array that extends in direction 411 or 412.
The electrical contacts 404 may include both signal contacts and ground contacts that vary in arrangement. For example, along each array that extends in the first or first direction, the contacts 404 may be in a signal-ground-signal arrangement, a ground-signal-ground-signal arrangement, or a ground-signal-signal arrangement. A plurality of differential signal pairs may be positioned adjacent to one another along the first direction or along the second direction, forming either broadside-coupled or edge-coupled differential signal pairs.
The contacts in the receptacle connector 402 may be of varying shapes and sizes.
The electrical contacts 512 may include both signal contacts and ground contacts that vary in size and arrangement. For example, along each array extending in the first or first direction, the contacts may be in a signal-ground-signal arrangement, a ground-signal-ground-signal arrangement, or a ground-signal-signal arrangement. As a complementary connector to the receptacle connector 502, the contacts in the header connector 508 are arranged in a ground-signal-ground-signal arrangement and are positioned edge-to-edge in an array extending in the second direction and broadside-to-broadside in an array extending in the first direction. For example, from right to left in the first array of contacts in the header connector 508 are ground contact 514, signal contact 516, ground contact 518, signal contact 520, and so on.
Each of the contacts 512 in the header connector 508 may have a respective mating portion that may be of varying shapes and sizes. For example, the ground contacts, such as example contact 514, are shown having a broadside that is less broad than the broadsides of the signal contacts, such as example signal contact 516. The mating end of each electrical contact 512 may be blade-shaped and may be adapted to mate with a respective electrical contact of the receptacle connector 502.
The header connector 508 may be mated to the receptacle connector 502 until the connector housing 510 of the header connector 508 abuts the connector housing 503 of the receptacle connector 502. The contact mating portions that are disposed in each aperture 504 in the receptacle connector 502 may mate with the contact mating portions of the header connector 508. As described herein, the ground contacts in the receptacle connector 502 may be shaped to bridge together a linear array of ground contacts 512 in the second connector when the connectors 502, 508 are mated. Thus, a ground may be established between the connectors 502, 508 by the mating of ground contacts 404, 512 from the respective connectors 502, 508. Such bridging tends to establish a continuous ground along a linear array of ground contacts, such as an array of header contacts extending in the first direction and starting with contact 518, which thereby creates a more robust ground.
The force may elongate the receptacle contact 124 and result in a force normal to each of the receptacle/header contact mating surfaces, such as at the points of contact 306, 308. The force exerted may retain the mating portion 132 of the receptacle contact 124 between the adjacent header contacts 110. Thus, a better electrical connection between the contacts 110, 124, as well as between the contacts 110, 122 may be made and sustained. As indicated, the deeper the insertion, the greater the resulting force. The increase in force may correspond to the insertion of the receptacle contact at the point where the first portion 216 of the receptacle contact 124 makes contact with the second header contact 110.
This is a continuation application of U.S. patent application Ser. No. 12/129,086, filed May 29, 2008, which in turn claims benefit under 35 U.S.C. §119(e) of provisional U.S. patent application No. 60/949,541, filed Jul. 13, 2007, the disclosure of each of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60949541 | Jul 2007 | US |
Number | Date | Country | |
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Parent | 12129086 | May 2008 | US |
Child | 12833322 | US |