Compliant pin for retaining and electrically connecting a shield with a connector assembly

A compliant pin is configured to be press-fit into a cavity of at least one of a connector assembly and a substrate to retain the pin in the cavity. The pin includes a neck, a plurality of compliant beams, and an insertion tip. The neck interconnects the pin with the connector assembly. The beams are configured to engage an inner surface of the cavity to retain the pin in the cavity. The beams are arranged side-to-side and project along a longitudinal plane in a loading direction. The beams have arcuate portions that are arched in different directions transverse to the longitudinal plane. The arcuate portions are shaped to deflect toward the longitudinal plane without substantially engaging one another. The insertion tip interconnects the ends of the beams.

BACKGROUND OF THE INVENTION

The subject matter herein generally relates to electrical connectors and, more particularly, to compliant pins for electrical connectors.

Known Eye-Of-Needle (“EON”) pins are used to mechanically and electrically connect shields in connector assemblies with at least one of another component of the connector assembly and a substrate. For example, known EON pins are used to electrically connect shields with the electric ground of a circuit board and/or a conductor that is electrically connected to the electric ground of the circuit board. The EON pins are press-fit into cavities in the circuit board and/or another component in the connector assembly. The EON pins include an approximately oval shaped opening enclosed by outwardly bent beams of the EON pins. The EON pins are press-fit into cavities by applying an insertion force on the EON pins in a loading direction directed into the cavities. Application of the insertion force on the EON pins in the loading direction forces the EON pins into the cavities. As the EON pins are forced into the cavities, the beams are bent toward each other. The beams engage the inner surface of the cavity to electrically and mechanically couple the pin with the circuit board and/or component in the connector assembly.

These EON pins are relatively large when compared to the size and dimensions of other known signal pins used in the same connector assemblies. Moreover, these EON pins require relatively large insertion forces when compared to the structural integrity of the EON pins. For example, the insertion forces required to press-fit the EON pins into the cavities frequently cause the EON pins to buckle if the EON pins are not perfectly aligned with the cavities.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a compliant pin is configured to be press-fit into a cavity of at least one of a connector assembly and a substrate to retain the pin in the cavity. The pin includes a neck, a plurality of compliant beams, and an insertion tip. The neck interconnects the pin with the connector assembly. The beams are configured to engage an inner surface of the cavity to retain the pin in the cavity. The beams are arranged side-to-side and project along a longitudinal plane in a loading direction. The beams have arcuate portions that are arched in different directions transverse to the longitudinal plane. The arcuate portions are shaped to deflect toward the longitudinal plane without substantially engaging one another. The insertion tip interconnects the ends of the beams.

In another embodiment, a connector assembly includes a contact module assembly and a shield. The contact module assembly includes a lead frame that has a cavity and is configured to electrically connect the connector assembly with an electric ground. The shield has a compliant pin press-fit into the cavity to retain the shield with respect to the lead frame and to electrically connect the shield with the electric ground. The pin includes a neck, a plurality of compliant beams and an insertion tip. The neck interconnects the pin with the shield. The beams are configured to engage an inner surface of the cavity to retain the pin in the cavity. The beams are arranged side-to-side and project along a longitudinal plane in a loading direction. The beams have arcuate portions that are arched in different directions transverse to the longitudinal plane. The arcuate portions arc shaped to deflect toward the longitudinal plane without substantially engaging one another. The insertion tip interconnects the ends of the beams.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view of an electrical connector assembly100according to one embodiment. While the connector assembly100is described herein with particular reference to a backplane receptacle connector, it is to be understood that the benefits herein described are also applicable to other connectors in alternative embodiments. The following description is therefore provided for purposes of illustration, rather than limitation, and is but one potential application of the subject matter herein. The connector assembly100includes a dielectric housing102having a forward mating end104that includes a shroud106having a mating interface108at the mating end104. A plurality of mating contacts200(shown inFIG. 2), such as, for example, contacts within contact cavities110, are provided proximate to the mating interface108and are configured to receive corresponding mating contacts (not shown) from a mating connector (not shown). The shroud106includes an upper surface112and a lower surface114between opposed sides116,118. The upper and lower surfaces112,114and sides116,118each include a chamfered forward edge portion120. An alignment rib122is formed on the upper surface112and lower surface114. The forward edge portion120and the alignment ribs122cooperate to bring the connector assembly100into alignment with the mating connector during the mating process so that the contacts in the mating connector are received in the contact cavities110without damage.

FIG. 2is an exploded view of the connector assembly100. As shown inFIG. 2, the housing102also includes a rearwardly extending hood202. A plurality of contact module assemblies204are received in the housing102from a rearward end206. The contact module assemblies204define a connector mounting interface208. The connector mounting interface208includes a plurality of mounting contacts220, such as, but not limited to, pin contacts, that are configured to be mounted to a substrate (not shown), such as, but not limited to, a circuit board. The mounting contacts220include ground and signal contacts. In one embodiment, the mounting interface208is substantially perpendicular to the mating interface108such that the electrical connector assembly100interconnects electrical components that are substantially at a right angle to one another. The housing102may hold two or more different types of contact module assemblies204, such as, but not limited to, contact module assemblies204A,204B. Alternatively, the housing102may hold only a single type of contact module assembly204, such as, but not limited to, any of the contact module assemblies204A,204B.

In an example embodiment, each of the contact module assemblies204includes a lead frame216that is partially housed in a dielectric body218. As illustrated inFIG. 2, the lead frame216is enclosed within the body218, but is at least partially exposed by the body218in certain areas. In one or more embodiments, the body218is manufactured using an over-molding process. During the molding process, the lead frame216is encased in a dielectric material, which forms the body218. The mating contacts200and mounting contacts220extend from the body218and the lead frame216. The contact module assemblies204include a shield212that extends along one side thereof. Optionally, the shield212may define a ground plane for the respective contact module assembly204. In the illustrated embodiment, the shield212includes a plurality of compliant pins214that electrically and mechanically connects to the lead frame216. Optionally, the shield212may be used to provide shielding between adjacent contact module assemblies204.

FIG. 3is an assembled view of the contact module assembly204A (shown inFIG. 2), with an example shield212affixed thereto. WhileFIG. 3illustrates the contact module assembly204A, the contact module assembly204B (shown inFIG. 2) also may include a similar shield212. The mating contacts200of the contact module assembly204A include a plurality of conductors, including both ground and signal conductors (identified inFIG. 3with a G for ground conductors or an S for signal conductors). The ground and signal conductors G, S extend at least partially into the contact module assembly204A. During assembly, the shield212is mounted to the contact module assembly204A. The compliant pins214of the shield212are electrically and mechanically connected to the ground conductors G of the mating and mounting contacts200,220. In one or more embodiments, the shield212is electrically connected to less than all of the ground conductors G. When installed, the shield212defines a ground plane that is oriented parallel to, but in a non-coplanar relation with, the lead frame plane. In one embodiment, when the shield212is installed, the shield212at least partially covers each of the ground and signal conductors G, S of the lead frame100. The shield212also is electrically connected with one or more of the ground conductors G. The ground conductors G are electrically connected to an electrical ground of the substrate (not shown) to which the connector assembly100(shown inFIG. 1) is mounted and/or an electrical ground of the mating connector (not shown) that mates with the connector assembly100. As a result, the shield212may effectively shield the signal conductors S from an adjacent contact module assembly204B (shown inFIG. 2) when the contact module assemblies204A,204B are assembled within the housing102.

FIG. 4is a perspective view of the compliant pin214prior to the pin214being press-fit into the lead frame216shown inFIG. 2according to one embodiment. The compliant pin214and shield212include, or are formed from, a conductive material such as a metal material. For example, the compliant pin214and shield212may be homogeneously formed with one another from a common piece of conductive metal. In one embodiment, the pin214and the shield212are stamped and formed from a common sheet of metal. The pin214and shield212may be coated with a conductive material, such as a conductive plating.

The pin214is coupled with the shield212of the connector assembly100(shown inFIG. 1) by a neck400. In the illustrated embodiment, the neck400is bent so that a longitudinal axis416of the pin214is approximately perpendicular to the shield212. Alternatively, the neck400may be bent so that the longitudinal axis416is not perpendicular to the shield212. For example, the longitudinal axis416may be parallel to the shield212.

A plurality of beams402,404is coupled to the neck400and interconnects the neck400with an insertion tip406. The beams402,404project from upper ends436,438to lower ends440,442along a longitudinal plane444of the pin214. The upper ends436,438are interconnected by the neck400and the lower ends440,442are interconnected by the insertion tip406. The longitudinal axis416of the pin214is disposed in the longitudinal plane444. In the illustrated embodiment, the longitudinal plane444is transverse to the shield212. For example, the longitudinal plane444is not parallel to the shield212inFIG. 4. In one embodiment, the longitudinal plane444is transverse to the shield212by being disposed at an acute angle with respect to the shield212. In another embodiment, the longitudinal plane444is transverse to the shield212by being disposed approximately perpendicular to the shield212. Alternatively, the pin214may be coupled to the shield212such that the longitudinal plane444is not transverse to the shield212. For example, the longitudinal plane444may be parallel to the shield212.

The beams402,404are bent so that the beams402,404outwardly protrude from the longitudinal plane444of the pin214in opposing directions. For example, the beams402,404include arcuate shapes that are arched in different directions408,410from the longitudinal plane444in the illustrated embodiment. The arcuate shape of the beams402,404may include a shape that is an approximately smooth arch and a shape that includes one or more approximately flat edges or surfaces such as contact surfaces606(shown inFIG. 6) of the beams402,404. As shown inFIG. 4, the left beam402is arched in one direction408and the right beam404is arched in a different direction410. In one embodiment, the directions408,410oppose one another. For example, the directions408,410may extend parallel to one another. Alternatively, the directions408,410may be skew with respect to one another. For example, the directions408,410may be disposed at an angle with respect to one another. The terms “left” and “right” are used merely as examples and are not intended to be limiting in any way. For example, the left beam402may be arched toward the direction410and the right beam404may be arched toward the other direction408. The beams402,404are disposed side-to-side so the beams402,404are arched away from the longitudinal plane444in different beam planes412,414. The beam planes412,414are parallel to one another and are transverse to the longitudinal plane444in the illustrated embodiment. For example, the beam planes412,414may be disposed at one or more acute angles with respect to the longitudinal plane444or may be disposed approximately perpendicular to the longitudinal plane444. In the illustrated embodiment, beams402,404are separated from one another by a separation gap422that extends approximately perpendicular to the beam planes412,414and along the longitudinal plane444such that the beams402,404are not arched away from one another in a single plane.

The neck400has a neck width424along the longitudinal plane444that is greater than a beams width426of the beams402,404that extends along the longitudinal plane444in the illustrated embodiment. For example, the neck width424between opposing neck sides428,430of the neck400in the longitudinal plane444is larger than the beams width426between outer surfaces432,434of the beams402,404in the longitudinal plane444. Providing the neck400with a greater neck width424than the beams width426of the beams402,404can increase the strength of the pin214so as to reduce the possibility of the pin214buckling when the pin214is press-fit into a cavity500(shown inFIG. 5).

An inner surface418of the pin214defines an opening420between the beams402,404. For example, the inner surface418may define the approximately oval-shaped opening420in the longitudinal plane444shown inFIG. 4. The opening420may have a different shape in another embodiment and/or in a different plane. The opening420extends in the longitudinal plane444between the neck400and the insertion tip406and separates the beams402,404from one another. The separation gap422defines the width of the opening420in the longitudinal plane444.

The insertion tip406includes a pointed shape that is pointed along the longitudinal axis416of the pin214. The pointed shape of the insertion tip406can reduce the force required to load the pin214into a cavity500(shown inFIG. 5) in the lead frame216(shown inFIG. 2). The insertion tip406projects away from the neck400along the longitudinal plane444in the illustrated embodiment.

FIG. 5illustrates a portion of the lead frame216and the dielectric body218shown inFIG. 2according to one embodiment. The lead frame216extends in a plane that is transverse to the pin214(shown inFIG. 2) in one embodiment. For example, a top surface508of the lead frame216may be disposed approximately perpendicular to, or at an acute angle with respect to, the longitudinal plane444(shown inFIG. 4) of the pin214. The lead frame216includes a plurality of cavities500that are each shaped to receive the pins214. The pins214are press-fit into the cavities500to mechanically secure and retain the shield212(shown inFIG. 2) with respect to the lead frame216. The dielectric body218includes a plurality of access openings502located over the cavities500. The access openings502are positioned to permit the pins214to be loaded into the cavities500so that the dielectric body218is located between the shield212and the lead frame216when the connector assembly100(shown inFIG. 1) is assembled. As described below, the pins214are press-fit into the cavities500to mechanically and electrically couple the shield212with the lead frame216. The cavities500may be formed in the lead frame216such that an inner surface616(shown inFIG. 6) of the cavities500is electrically connected with the lead frame216and one or more ground conductors G. For example, the lead frame216may include, or be formed from a conductive material with the cavities500exposing an inner conductive portion of the lead frame216. Alternatively, the inner surface616(shown inFIG. 6) of each cavity500may include, or be at least partially coated with, a conductive material. Mounting the shield212to the lead frame216using the pins214can electrically connect the shield212to an electric ground of the lead frame216.

The cavities500define a polygon-shaped opening506in the top surface508of the lead frame216in one embodiment. For example, each of the cavities500inFIG. 5defines a rectangular shaped opening506in the lead frame216. Alternatively, the cavities500may define a different shaped opening506or a polygon-shaped opening506that is a polygon shape other than a rectangle. The openings506have a width510that is greater than a height504in the illustrated embodiment. For example, the width510of the openings506may be approximately 0.6 millimeters and the height504may be approximately 0.4 millimeters. In one embodiment, the width510and height504of the openings506are smaller than the dimensions of openings (not shown) in known lead frames (not shown) that receive pins (not shown) to electrically and mechanically connect a shield (not shown) with the lead frame. Reducing the size of the openings506can reduce the pitch of the pins214(shown inFIG. 2) that are press-fit into the cavities500. For example, reducing the size of the openings506can allow for the cavities500and the pins214to be provided closer together than in known connector assemblies. Reducing the size of the openings506also can reduce the amount of conductive material that surrounds each opening506. For example, reducing the dimensions of the openings506can reduce the amount of conductive material that is coated on the lead frame216around and/or in the cavities500.

FIG. 6is a side elevational view of the pin214prior to loading the pin214into the cavity500according to one embodiment. The lead frame216and dielectric body218are shown in cross-sectional view inFIG. 6. Additionally, the pin214inFIG. 6is presented as though viewed from a direction that is transverse to the beam planes412,414(shown inFIG. 4) and is along the longitudinal plane444(shown inFIG. 4). The longitudinal plane444may be represented by the longitudinal axis416as shown inFIG. 6. The pin214is loaded into the cavity500in a loading direction608. The loading direction608is approximately parallel to the longitudinal axis416and along the longitudinal plane444of the pin214in one embodiment.

As described above, the beams402,404are arched in opposing directions408,410(shown inFIG. 4). In the illustrated embodiment, the beams402,404are arched so as to define an opening600between the beams402,404when the beams402,404are viewed from a direction that is transverse to the longitudinal axis416and along the longitudinal plane444(shown inFIG. 4) of the pin214. For example, the opening600is defined in a plane that is approximately parallel to the beam planes412,414(shown inFIG. 4) and transverse to the longitudinal plane444. Each of the beams402,404includes lower and upper angled surfaces602,604with a contact surface606between the lower and upper angled surfaces602,604. In the illustrated embodiment, the contact surfaces606are approximately parallel to one another. As the pin214is loaded into the cavity500in the loading direction608, the lower angled surface602of each beam402,404first engages an upper edge610of the cavity500. The upper edge610of the cavity500is the edge of the opening506(shown inFIG. 5) defined by the cavity500. A depth612of the beams402,404is the distance between the contact surfaces606of the beams402,404in a direction that is transverse to the longitudinal plane444(shown inFIG. 4). The depth612of the beams402,404is greater than an inner dimension614of the cavity500. The inner dimension614is the distance between opposing sides of an inner surface616of the cavity500in a direction that is parallel to the direction in which the depth612is measured.

FIG. 7is a side elevational view of the pin214after being loaded into the cavity500according to one embodiment. In a manner similar toFIG. 6,FIG. 7presents the lead frame216and dielectric body218in cross-sectional view and the pin214as though viewed from a direction that is transverse to the beam planes412,414and is along the longitudinal plane444as shown inFIG. 4. The lower angled surfaces602of the beams402,404slide along the upper edge610of the cavity500as the pin214is press-fit into the cavity500along the loading direction608. The beams402,404are deflected in deflection directions700,702as the pin214is press-fit into the cavity500. For example, as described above and shown inFIG. 4, the left beam402is arched along the direction408and the right beam404is arched along the different direction410. Pressing the pin214into the cavity500causes the beams402,404to be at least partially deflected toward the longitudinal plane444(shown inFIG. 4) in deflection directions700,702. For example, the beams402,404may be partially flattened toward the longitudinal plane444. In one embodiment, the deflection directions700,702are different from one another. For example, the deflection directions700,702may oppose one another. In another example, the deflection directions700,702are disposed at an acute angle with respect to one another. In the illustrated embodiment, the deflection direction700of the beam402is substantially opposite to the direction408in which the beam402is arched in the beam plane412(shown inFIG. 4) and the deflection direction702of the beam404is substantially opposite to the direction410in which the beam404is arched in the beam plane414(shown inFIG. 4).

Once the pin214is press-fit into the cavity500, the contact surfaces606of the beams402,404engage one or more of the inner surface616and the upper edge610of the cavity500to retain the pin214in the cavity500, and thus secure the shield212in position with respect to the lead frame216. The contact surfaces606engage one or more of the inner surface616and the upper edge610to electrically connect the pin214and the lead frame216.

With additional reference toFIG. 4, the beams402,404are separated from one another by the separation gap422prior to, during and after the pin214is press-fit into the cavity500in one embodiment. The beams402,404are separated from one another so that the beams402,404do not substantially engage one another as the beams402,404are deflected along the deflection directions700,702. For example, the portions of the inner surface418of the pin214that are located proximate to the beams402,404are separated from one another such that the beams402,404do not rub against, slide against or otherwise engage one another when the pin214is press-fit into the cavity500such that the beams402,404do not frictionally engage one another. In one embodiment, the greatest separation gap422in the longitudinal plane444between the beams402,404is approximately the same before and after the pin214is press-fit into the cavity500. For example, the initial width of the opening420may not substantially change after the pin214is press-fit into the cavity500. In another example, the opening420separates the beams402,404and extends between the neck400and the insertion tip406before and after the pin214is press-fit into the cavity500and the beams402,404are biased in the directions700,702.

The beams402,404do not substantially engage one another to avoid significantly increasing the amount of loading force that is applied to the pin214in the loading direction608to press-fit the pin214into the cavity500. For example, the beams402,404do not substantially engage one another when the pin214is press-fit into the cavity500to avoid requiring a loading force that would cause the pin214to buckle if the pin214is misaligned with respect to the cavity500. In another example, the loading force that is applied to the pin214in the loading direction608to press-fit the pin214in the cavity500is reduced over known compliant pins. Reducing the amount of loading force that is required to press-fit the pin214into the cavity500can reduce the chances of the pin214buckling. For example, as the amount of insertion force that is required to press-fit a known pin (not shown) into a known cavity (not shown) increases, the pin is more likely to buckle. Conversely, as the amount of insertion force that is required to press-fit the pin214is reduced over known pins, the pin214is less likely to buckle when loaded into the cavity500.

Keeping the beams402,404separated as the pin214is press-fit into the cavity500can prevent parts of the beams402,404from shearing or peeling off of the pin214. For example, a conductive plating on the pin214may be prevented from being skived from the beams402,404by separating the beams402,404from one another during loading of the pin214into the cavity500. In doing so, at least some of the conductive plating on the beams402,404is protected from being removed, thus exposing the underlying base material of the pin214, in one embodiment.

In the illustrated embodiment, the beams402,404are deflected toward the deflection directions700,702as the pin214is loaded into the cavity500sufficiently far so that the opening600(shown inFIG. 6) is closed in a plane that is approximately parallel to the beam planes412,414and transverse to the longitudinal plane444. For example, the opening600that is visible from a direction that is transverse to the beam planes412,414(shown inFIG. 4) prior to press-fitting the pin214into the cavity500may no longer be visible from this same direction after the pin214is loaded into the cavity500. The opening600may no longer be visible due to the biasing of the beams402,404toward directions700,702sufficiently far to eliminate or close the opening600when viewed from the direction transverse to the beam planes412,414.

FIG. 8is a partial cross-sectional view of the beams402,404after the pin214(shown inFIG. 2) is press-fit into the cavity500taken along line8-8inFIG. 7. Only cross-sections of the beams402,404are shown inFIG. 8with the rest of the pin214removed from the view ofFIG. 8. As described above, the beams402,404are separated by the separation gap422prior to and after the pin214is press-fit into the cavity500in one embodiment. The beams402,404have a polygon-shaped cross-sectional shape in a plane that is parallel to the top surface508(shown inFIG. 5) of the lead frame216. For example, the beams402,404may have a square- or rectangular-shaped cross-section. The cross-sectional shape of the beams402,404can increase the retention of the pin214in the cavity500. For example, the cross-sectional shape of the beams402,404can increase the surface area of the interface between the beams402,404and the lead frame216. Increasing the surface area of the interface between the beams402,404and the lead frame216can increase the amount of force required to remove the pin214from the cavity500.

For example, the interface between the pin214(shown inFIG. 2) and the lead frame216includes a plurality of interface areas800,802between the contact surfaces606of the beams402,404and at least one of the inner surface616and the upper edge610of the cavity500. While only the inner surface616is labeled inFIG. 8, the upper edge610also may be labeled using the same arrow as is used to label the location of the inner surface616. The interface areas800,802include the surface area in which the contact surfaces606engage the inner surface616within the cavity500and/or the upper edge610of the cavity500. The engagement between the substantially flat contact surfaces606and one or more of the inner surface616and upper edge610increases the surface area of the interface areas800,802between the pin214and the lead frame216when compared to known pins (not shown) and cavities (not shown) of a similar size and of a different shape. Increasing this surface area causes the force required to remove the pin214from the cavity500to be increased.

In one embodiment, the width510of the opening506defined by the cavity500is greater than the beam width426of the beams402,404. For example, the opening506of the cavity500may be sufficiently large such that one or more side gaps804,806are provided between outside surfaces432,434of the beams402,404and opposing sides of the inner surface616of the cavity500. The outside surfaces432,434of the beams402.404include the outermost surfaces of the beams402,404in a plane that is perpendicular to the beam planes412,414in one embodiment. For example, the beans width426of the beams402,404may be defined as the distance between the outside surfaces432,434of the beams402,404in a direction that is perpendicular to the one or more of the beam planes412,414and the longitudinal axis416(shown inFIG. 4) of the pin214. The opening506may be sufficiently large to provide the side gaps804,806when the pin214is press-fit into the cavity500to provide additional tolerance for the loading of the pin214into the cavity500. For example, inclusion of the side gaps804,806can provide additional tolerance for the location of the pin214in the cavity500so that the pin214does not need to be perfectly centered in the opening506.