Patent Description:
Due to the increasing complexity of electronic components, it is desirable to fit more components in less space on a circuit board or other substrate. Consequently, the spacing between electrical terminals within connectors has been reduced, while the number of electrical terminals housed in the connectors has increased, thereby increasing the need in the electrical arts for electrical connectors that are capable of handling higher and higher speeds and to do so with greater and greater pin densities. It is desirable for such connectors to have not only reasonably constant impedance levels, but also acceptable levels of impedance and cross-talk, as well as other acceptable electrical and mechanical characteristics. Therefore, there remains a need to provide appropriate shielding to preserve signal integrity and to minimize cross-talk as speeds of signals increase as the footprint of the connector maintains or increases density of the signal pairs.

A connector having the features set out in the preamble of claim <NUM> is disclosed in <CIT>. Similar connectors are disclosed in <CIT> and <CIT>. <CIT> and <CIT> disclose connectors in which dielectric components are coated with conductive material.

It would, therefore, be beneficial to provide a connector which reduces cross-talk between contact pairs. In addition, it would be beneficial to provide a such connector which can be manufactured in a manner, such as by applying a conductive coating to an insulative member of the housing which is optimized for impedance.

According to the invention there is provided an electrical connector as set out in claim <NUM>.

The invention is defined by the independent claim, and is directed to an electrical connector for use in an electrical connector system which controls cross-talk, signal radiation and impedance.

<FIG> illustrate an electrical connector system <NUM> including a connector not falling within the scope of the invention, which is useful for explaining a connector falling within the scope of the invention. The electrical connector system <NUM> includes a backplane connector <NUM> and a daughtercard connector <NUM> that are used to electrically connect a backplane circuit board (not shown) and a daughtercard circuit board (not shown). While the electrical connector system <NUM> is described herein with reference to backplane connectors <NUM> and daughtercard connectors <NUM>, it is realized that the subject matter herein may be utilized with different types of electrical connectors other than a backplane connector or a daughtercard connector. The backplane connector <NUM> and the daughtercard connector <NUM> are merely illustrative components of an electrical connector system <NUM> that interconnects a particular type of circuit board, namely a backplane circuit board, with a daughtercard circuit board.

In the illustrative system shown, the daughtercard connector <NUM> constitutes a right angle connector wherein a mating interface <NUM> and mounting interface <NUM> of the daughtercard connector <NUM> are oriented perpendicular to one another. The daughtercard connector <NUM> is mounted to the daughtercard circuit board at the mounting interface <NUM>. Other orientations of the interfaces <NUM>, <NUM> are possible in alternative systems.

As shown in <FIG>, <FIG> and <FIG>, the daughtercard connector <NUM> includes a housing <NUM>, made of one or more components, holding a plurality of circuit boards <NUM> therein. The circuit boards <NUM> have pairs <NUM> of individual signal pathways or traces (not shown) that extend between the mating interface <NUM> and the mounting interface <NUM>. The signal traces have signal conductive pads <NUM> provided proximate the mating interface <NUM>. The signal traces are configured to be mated with and electrically connected to the signal contacts <NUM> of the backplane connector <NUM>. The circuit boards <NUM> have individual ground pathways or traces that extend between the mating interface <NUM> and the mounting interface <NUM>. The ground traces (not shown) have ground conductive pads <NUM> provided proximate the mating interface <NUM>. The ground traces are configured to be mated with, and electrically connected to, the ground contacts <NUM> or the shield or ground plates <NUM> of the backplane connector <NUM>. The circuit boards <NUM> also have ground pathways or traces <NUM> on opposites sides of the circuit boards <NUM> from the ground traces. The ground traces <NUM> extend between the mating interface <NUM> and the mounting interface <NUM>. In alternative systems, the circuit boards <NUM> may be contact modules, the signal traces may be mating signal contacts and the ground traces may be ground contacts.

In the illustrated system, the backplane connector <NUM> constitutes a header connector mounted to the backplane circuit board. The backplane connector <NUM> is mated to the daughtercard connector <NUM>. When mated, the daughtercard circuit board is oriented generally perpendicular with respect to the backplane circuit board.

The backplane connector <NUM> includes a mating end <NUM> and a mounting end <NUM> that are oriented generally parallel to one another. The backplane connector <NUM> is mounted to the backplane circuit board at the mounting end <NUM>.

The backplane connector <NUM> includes a housing <NUM> which includes a plurality of modules <NUM>. Each of the modules <NUM> has a mating end <NUM> , also referred to herein as a front end <NUM> , that is positioned in a recess <NUM> of the daughtercard connector <NUM> during mating. Each of the modules <NUM> has a mounting end <NUM>, also referred to herein as a rear end <NUM>, which is mounted to the backplane circuit board. Each of the modules <NUM> holds a plurality of individual signal contacts <NUM> that extend between the mating end <NUM> and the mounting end <NUM>. In an exemplary system, the signal contacts <NUM> are arranged in pairs carrying differential signals. Each of the modules <NUM> also holds a plurality of ground contacts <NUM> that extend between the mating end <NUM> and the mounting end <NUM>.

As shown in <FIG>, each module <NUM> has a conductive first housing <NUM> and at least one second housing <NUM>. In the illustrative system shown, three second housings <NUM> are provided, but other numbers and configurations of the second housings <NUM> may be provided.

Each of the conductive first housings <NUM> has a first surface <NUM> and an oppositely facing second surface <NUM>. At least one second housing receiving recess <NUM> extends from the first surface <NUM> toward the second surface <NUM>. The first housing <NUM> is an insulative member made of an insulative material with a conductive coating <NUM> applied to the outer surfaces of the first housing <NUM>. The conductive coating <NUM> may be applied by known methods or processes, including, but not limited to, an electroless process, an electroplating process or a physical vapor deposition process. The conductive coating <NUM> allows the first housing <NUM> to act as a shield, as will be more fully described, while allowing the modules <NUM> and the backplane connector <NUM> to mate with existing daughtercard connectors <NUM>. As the first housing <NUM> is made from an insulative materials, such as, but not limited to, plastic, the shape of the first housing <NUM> can be molded or manufactured in a shape which optimizes the impedance characteristics of the first housing <NUM> when the conductive coating <NUM> is applied.

The conductive first housings <NUM> of the modules <NUM> include a plurality of ground cavities or channels <NUM> extending between the mating end <NUM> and the mounting end <NUM> of the first surface <NUM>. The ground channels <NUM> extend from the first surface <NUM> toward the second surface <NUM> along the mating axes and receive the ground contacts <NUM>. When the backplane connector <NUM> and daughtercard connector <NUM> are mated, ground conductive pads <NUM> of the ground traces of the daughtercard connector <NUM> are also received in the ground channels <NUM>. Any number of ground channels <NUM> may be provided. The ground channels <NUM> may be provided at any locations within the modules <NUM> and the housing <NUM>. In an exemplary system, the ground channels <NUM> are generally positioned adjacent to and/or between the second housing receiving recesses <NUM>.

The second housings <NUM> have a first surface <NUM> and an oppositely facing second surface <NUM>. The second housings <NUM> are insulative members made of an insulative material. The second housings <NUM> may be separate components which are assembled to the first housings <NUM> using known methods, such as, but not limited to, adhesion, interference fit, overmolding and/or mounting projections.

The second housings <NUM> of the modules <NUM> include a plurality of signal cavities or channels <NUM> extending between the mating end <NUM> and the mounting end <NUM> of the first surface <NUM>. The signal channels <NUM> extend along the mating axes and receive the signal contacts <NUM>. When the backplane connector <NUM> and daughtercard connector <NUM> are mated, the signal conductive pads <NUM> of the mating signal traces of the daughtercard connector <NUM> are also received in the signal channels <NUM>. In the illustrative system shown, two signal cavities or channels <NUM> are provided in each of the second housings <NUM>, however, other numbers of signal cavities or channels <NUM> may be provided.

In the illustrative system shown in <FIG> and <FIG>, the housing <NUM> of the backplane connector <NUM> has four modules <NUM> which are positioned adjacent to each other. However, other number of modules may be used. Circuit board receiving slots <NUM> are provided between adjacent modules <NUM>. The circuit board receiving slots <NUM> are positioned adjacent mating connector receiving sections <NUM> of the modules <NUM>. Each circuit board receiving slot <NUM> extends from the mating end <NUM> of the module toward the mounting end <NUM>.

Each of the first housings <NUM> of the modules <NUM> has a base section <NUM> which extends from the mounting end <NUM> toward the mating end <NUM>. The base section <NUM> has end sections <NUM> which extend beyond the connector receiving sections <NUM>, as shown in <FIG>. Each of the end sections <NUM> has a clip receiving slot <NUM> which extends from a top surface <NUM> of the end section <NUM> toward the mounting end <NUM>.

When the modules <NUM> are properly assembled, as shown in <FIG>, clips <NUM> are inserted into the clip receiving slots <NUM> to properly position and retain the modules <NUM> in position relative to each other.

Referring to <FIG> and <FIG>, the signal channels <NUM> and ground channels <NUM> are shown. As previously described, the signal channels <NUM> are configured to receive the signal contacts <NUM> therein. As shown in <FIG>, each signal contact <NUM> has a mating contact receiving section <NUM>, a securing section <NUM> and circuit board mounting section <NUM>. In the illustrative system shown, the contact receiving section <NUM> includes two resilient arms <NUM> with lead-in portions <NUM> and engagement portions <NUM>. The resilient arms <NUM> are configured to press against the signal conductive pads <NUM> of the signal traces when the daughter card connector <NUM> is mated to the backplane connector <NUM>. The circuit board mounting section <NUM> has a compliant portion <NUM>, such as an eye of the needle pin, although other configurations may be used. Each of the circuit board mounting section <NUM> has a longitudinal axis which is offset from the longitudinal axis of the securing section <NUM> and the mating contact receiving section <NUM>. In various illustrative systems, the signal contacts <NUM> of one module <NUM> have the circuit board mounting section <NUM> offset to the right, while the signal contacts <NUM> of another module <NUM> have the circuit board mounting section <NUM> offset to the left. As the mounting section <NUM> of the signal contacts <NUM> in one module <NUM> are offset from the mounting section <NUM> of the signal contacts <NUM> in an adjacent module <NUM>, the cross-talk is reduced in the footprint of the backplane connector <NUM>, as the staggered pattern is configured for cancellation.

As previously described, the ground channels <NUM> are configured to receive the ground contacts <NUM> therein. Each ground contact <NUM> has a contact section <NUM>, a securing section <NUM> and circuit board mounting section <NUM>. In the illustrative system shown, the contact section <NUM> includes two resilient arms <NUM> with lead-in portions <NUM> and engagement portions <NUM>. The resilient arms <NUM> are configured to press against the ground conductive pads <NUM> of the ground traces when the daughter card connector <NUM> is mated to the backplane connector <NUM>.

The circuit board mounting section <NUM> has a compliant portion <NUM>, such as an eye of the needle pin, although other configurations may be used. Each of the circuit board mounting section <NUM> has a longitudinal axis which is offset from the longitudinal axis of the securing section <NUM> and the contact section <NUM>. In various illustrative systems, the ground contacts <NUM> of one module <NUM> have the circuit board mounting section <NUM> offset to the right, while the ground contacts <NUM> of another module <NUM> have the circuit board mounting section <NUM> offset to the left.

With the housing <NUM> properly assembled, the ground contacts <NUM> and the conductive first housings <NUM> with the conductive coatings <NUM> extend about the periphery of the pairs of signal contacts <NUM> and surround the pairs of signal contacts <NUM> to provide electrical shielding for the pairs of signal contacts <NUM>. Respective ground contacts <NUM> are positioned adjacent to the at least one second housing <NUM> and respective signal contacts <NUM>. In an exemplary system, entire, <NUM> degree shielding is provided by the ground contacts <NUM> and the conductive first housings <NUM> along the length of the signal contacts <NUM>. The ground contacts <NUM> and the conductive first housings <NUM> surround portions of the mating signal traces when the connectors <NUM>, <NUM> are mated. The ground contacts <NUM> and the conductive first housings <NUM> provide shielding along the entire mating interface with the mating signal traces. The ground contacts <NUM> and the conductive first housings <NUM> may control electrical characteristics throughout the housing <NUM>, such as by controlling cross-talk, signal radiation, impedance or other electrical characteristics.

With the daughtercard connector <NUM> properly mated to the backplane connector <NUM>, the circuit boards <NUM> of the daughter card connector <NUM> are positioned in the circuit board receiving slots <NUM>. In this position, the signal contacts <NUM> of the modules <NUM> physically and electrically engage the signal conductive pads <NUM> of the signal traces of the circuit boards <NUM>. The ground contacts <NUM> of the modules <NUM> are also placed in physical and electrical engagement with the ground conductive pads <NUM> of the ground traces of the circuit boards <NUM>. In addition, the conductive first housings <NUM> physically and electrically engage the ground contacts <NUM>.

The ground contacts <NUM> and the conductive first housings <NUM> provide shielding for the signal contacts <NUM> and the portions of the signal conductive pads <NUM> of the signal traces of the circuit boards <NUM> which are positioned in the circuit board receiving slots <NUM> of the modules <NUM> of the housing <NUM> of the backplane connector <NUM>.

Referring to <FIG>, a module <NUM> for use in a connector according to the invention is shown. Each module <NUM> has a conductive first housing <NUM> and at least one second housing <NUM>. In the illustrative embodiment shown, two second housings <NUM> are provided, but other numbers and configurations of the second housings <NUM> may be provided.

As shown in <FIG>, each of the conductive first housings <NUM> has a first surface <NUM> and an oppositely facing second surface <NUM>. At least one second housing receiving recess <NUM> extends from the first surface <NUM> toward the second surface <NUM>. The first housing <NUM> is an insulative member made of an insulative material with a conductive coating <NUM> applied to the outer surfaces of the first housing <NUM>. The conductive coating <NUM> may be applied by known methods or processes, including, but not limited to, an electroless process, an electroplating process or a physical vapor deposition process. The conductive coating <NUM> allows the first housing <NUM> to act as a shield, as will be more fully described, while allowing the modules <NUM> and the backplane connector <NUM> to mate with existing daughtercard connectors <NUM>. As the first housing <NUM> is made from an insulative materials, such as, but not limited to, plastic, the shape of the first housing <NUM> can be molded or manufactured in a shape which optimizes the impedance characteristics of the first housing <NUM> when the conductive coating <NUM> is applied.

The conductive first housings <NUM> of the modules <NUM> include a plurality of first ground cavities or channels <NUM> and second ground cavities or channels <NUM> extending from the first surface <NUM> toward the second surface <NUM>. When the backplane connector <NUM> and daughtercard connector <NUM> are mated, ground conductive pads <NUM> of the ground traces of the daughtercard connector <NUM> are also received in the ground channels <NUM>. Any number of first ground channels <NUM> and second ground channels <NUM> may be provided. The ground channels <NUM> and second ground channels <NUM> may be provided at any locations within the modules <NUM>. In an exemplary embodiment, the ground channels <NUM> and second ground channels <NUM> are generally positioned adjacent to and/or between the second housing receiving recesses <NUM>.

The conductive first housings <NUM> of the modules <NUM> also include a plurality of third ground cavities or channels <NUM> extending from the second surface <NUM> toward the first surface <NUM>. The third ground cavities or channels <NUM> intersect with the first cavities or channels <NUM> proximate the mating end <NUM>.

The second housings <NUM> of the modules <NUM> include a plurality of signal cavities or channels <NUM> extending between the mating end <NUM> and the mounting end <NUM>. The signal channels <NUM> extend along the mating axes and receive the signal contacts <NUM>. When the backplane connector <NUM> and daughtercard connector <NUM> are mated, the signal conductive pads <NUM> of the mating signal traces of the daughtercard connector <NUM> are also received in the signal channels <NUM>. In the illustrative embodiment shown, two signal cavities or channels <NUM> are provided in each of the second housings <NUM>, however, other numbers of signal cavities or channels <NUM> may be provided.

As previously described, the signal channels <NUM> are configured to receive the signal contacts <NUM>. The signal contacts <NUM> are similar to the signal contacts <NUM> previously described.

The ground channels <NUM> and ground channels <NUM> are configured to receive the ground contacts <NUM> therein. Each ground contact <NUM> has a first contact section <NUM>, a bent or securing section <NUM> and a second contact section <NUM>. In the illustrative embodiment shown, the first contact section <NUM> has two resilient arms <NUM>. The resilient arms <NUM> are configured to press against the ground conductive pads <NUM> of the ground traces when the daughter card connector <NUM> is mated to the backplane connector <NUM>.

The bent section <NUM> extends between the first contact section <NUM> and the second contact section <NUM>. The bent section <NUM> also extends between the first ground cavities or channels <NUM> on the first surface <NUM> and the third ground cavities or channels <NUM> on the second surface <NUM>. The second contact sections <NUM> have projection <NUM> which extend beyond the second surface <NUM> to physically and electrically engage the ground traces <NUM> of the circuit boards <NUM>.

The ground channels <NUM> are configured to receive the ground contacts <NUM> therein. Each ground contact <NUM> has a module engagement section and a circuit board mounting section <NUM>. The circuit board mounting section <NUM> has a compliant portion <NUM>, such as an eye of the needle pin, although other configurations may be used.

With the housing <NUM> properly assembled, the ground contacts <NUM> and the conductive first housings <NUM> with the conductive coatings <NUM> extend about the periphery of the pairs of signal contacts <NUM> and surround the pairs of signal contacts <NUM> to provide electrical shielding for the pairs of signal contacts <NUM>. Respective ground contacts <NUM> are positioned adjacent to the at least one second housing <NUM> and respective signal contacts <NUM>. In an exemplary embodiment, entire, <NUM> degree shielding is provided by the ground contacts <NUM> and the conductive first housings <NUM> along the length of the signal contacts <NUM>. The ground contacts <NUM> and the conductive first housings <NUM> surround portions of the mating signal traces when the connectors <NUM>, <NUM> are mated. The ground contacts <NUM> and the conductive first housings <NUM> provide shielding along the entire mating interface with the mating signal traces. The ground contacts <NUM> and the conductive first housings <NUM> may control electrical characteristics throughout the housing <NUM>, such as by controlling cross-talk, signal radiation, impedance or other electrical characteristics.

Referring to <FIG>, an illustrative module <NUM> for use in a connector not falling within the scope of the invention is shown. Each module <NUM> has a conductive first housing <NUM> and at least one second housing <NUM>.

The conductive first housing <NUM> has a first surface <NUM> and an oppositely facing second surface <NUM>. At least one second housing receiving recess <NUM> extends from the first surface <NUM> toward the second surface <NUM>. The first housing <NUM> is an insulative member made of an insulative material with a conductive coating <NUM> applied to the outer surfaces of the first housing <NUM>. The conductive coating <NUM> may be applied by known methods or processes, including, but not limited to, an electroless process, an electroplating process or a physical vapor deposition process. The conductive coating <NUM> allows the first housing <NUM> to act as a shield, as will be more fully described, while allowing the modules <NUM> and the backplane connector <NUM> to mate with existing daughtercard connectors <NUM>. As the first housing <NUM> is made from an insulative materials, such as, but not limited to, plastic, the shape of the first housing <NUM> can be molded or manufactured in a shape which optimizes the impedance characteristics of the first housing <NUM> when the conductive coating <NUM> is applied.

The conductive first housings <NUM> of the modules <NUM> include a plurality of ground shield receiving channels or cavities <NUM> extending from the second surface <NUM> toward the first surface <NUM>. The ground shield receiving channels <NUM> are provided in alignment with the second housing receiving recesses <NUM>.

The second housing <NUM> has a first surface <NUM> and an oppositely facing second surface <NUM>. The second housing <NUM> is made of an insulative material. In other systems, the second housing <NUM> may have separate components which are assembled to the first housings <NUM> using known methods, such as, but not limited to, adhesion, interference fit, overmolding and/or mounting projections.

The second housing <NUM> of the modules <NUM> includes a plurality of signal cavities or channels <NUM> extending between the mating end <NUM> and the mounting end <NUM>. The signal channels <NUM> extend along the mating axes and receive the signal contacts <NUM>. When the backplane connector <NUM> and daughtercard connector <NUM> are mated, the signal conductive pads <NUM> of the mating signal traces of the daughtercard connector <NUM> are also received in the signal channels <NUM>. In the illustrative system shown, two pairs of signal cavities or channels <NUM> are provided in the second housing <NUM>, however, other numbers of signal cavities or channels <NUM> may be provided.

The ground shield receiving channels <NUM> are configured to receive shield or ground plates <NUM> therein. In the illustrative system shown, the second housing <NUM> is overmolded over the shield or ground plates <NUM>. The shield or ground plates <NUM> are positioned to mechanically and electrically engage the ground traces <NUM> to provide proper shielding to control cross-talk, signal radiation, impedance or other electrical characteristics.

Claim 1:
An electrical connector (<NUM>) for use in an electrical connector system (<NUM>) which controls cross-talk, signal radiation and impedance, the electrical connector (<NUM>) comprising:
a plurality of modules (<NUM>), the modules (<NUM>) having mating ends (<NUM>) and mounting ends (<NUM>);
each of the modules (<NUM>) of the plurality of modules (<NUM>) comprising:
a conductive first housing (<NUM>), the first housing (<NUM>) having at least one second housing recess (<NUM>) provided in a first surface (<NUM>) of the first housing (<NUM>), the first housing (<NUM>) having ground contact receiving channels (<NUM>) provided in the first surface (<NUM>) of the first housing (<NUM>);
at least one second housing (<NUM>) provided in the at least one second housing recess (<NUM>), the at least one second housing (<NUM>) being made of insulative material, the at least one second housing (<NUM>) having signal contact receiving channels (<NUM>) provided in a first surface (<NUM>) of the at least one second housing (<NUM>);
signal contacts (<NUM>) positioned in the signal contact receiving channels (<NUM>) of the at least one second housing (<NUM>);
ground contacts (<NUM>) positioned in the ground contact receiving channels (<NUM>) of the first housing (<NUM>, <NUM>),
characterised in that the first housing (<NUM>) has ground contact receiving channels (<NUM>) provided in a second surface (<NUM>) of the first housing (<NUM>), and respective ground contacts (<NUM>) of the ground contacts (<NUM>) extend from in the ground contact receiving channels (<NUM>) provided in the first surface (<NUM>) of the first housing (<NUM>) to the ground contact receiving channels (<NUM>) provided in the second surface (<NUM>) of the first housing (<NUM>) and have projections (<NUM>) which extend from the second surface (<NUM>) to engage grounding contacts (<NUM>) of a mating connector (<NUM>).