High density backplane connector having improved terminal arrangement

A high density backplane connector (100) includes a group of terminal pairs (17, 18, 27, 28) arranged along a first direction. Each terminal pair includes a first terminals (12, 22) and a second terminals (14, 24) substantially aligned with each other along a second direction perpendicular to the first direction. The first terminal has a first engaging portion (124, 224) and a first tail portion (125, 225). The second terminal has a second engaging portion (144, 244) extending beyond the first engaging portion and a second tail portion (145, 245). The first and second tail portions of the terminal pairs are arranged substantially in a line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is related to a pending U.S. patent application Ser. No. 12/148,757, filed on Apr. 22, 2008, and entitled “HIGH DENSITY CONNECTOR HAVING TWO-LEVELED CONTACT INTERFACE”, which is assigned to the same assignee with this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electrical connector, and particularly to a high density backplane connector in which contact engaging portions of a male connector are arranged in first and second columns, and while a mating intersection of a receptacle connector is also arranged in first and second columns corresponding to the second and first columns of the contact engaging portions, respectively.

2. Description of Related Art

Backplane connector is generally configured with a wafer on which about four contacts, say first, second, third and fourth contacts are arranged in a single plane. For explanation, the first contact will referred to the contact closer to a motherboard, while the fourth contact will be the contact most distant to the mother. Since those four contacts are generally arranged in right-angle, the overall length of those four contacts vary accordingly, i.e. the first contact has the shortest overall length, while the fourth contact has the longest overall length. As a result, a single skew will be encountered. The same applies to a differential pairs are well since the contact lengths are different from each other within the pairs when it is arranged in right-angle.

The right angle configuration of the typical backplane connector provides variable lengths in signal transmission paths. The paths go from shortest to longest as contacts move further away from the component side of the daughter board. Signal launched at the same time would arrive at different times at the far end of the connector due to the difference in length, or skew, of the transmission paths. In a differential pair configuration, this difference in length, or skew, must be compensated for and is typically handled by the printed circuit board (PCB) designer. Some connectors are designed to provide skew compensation by adding air in the areas where the transmission paths bend on the longer path of the two paths within the differential pair. This allows the signal to travel faster around the bends of the longer path in an attempt to get the signals to arrive at the same time at the far end. The typical connector is described either in U.S. Pat. No. 7,229,318 issued to Winings et al. on Jun. 12, 2007 or U.S. Pat. No. 7,390,218 issued to Smith et al. on Jun. 24, 2008.

However, this method would have a detrimental effect impedance and increased crosstalk.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a high density backplane connector having improved effect of reducing crosstalk by providing substantially equal signal transmission paths among the contacts.

To achieve the aforementioned objects, a high density backplane connector includes a group of terminal pairs and a group of contact pairs arranged along a first direction. Each terminal pair includes a first terminal and a second terminals substantially aligned with each other along a second direction perpendicular to the first direction. The first terminal has a first engaging portion and a first tail portion. The second terminal has a second engaging portion and a second tail portion. The first and second tail portions of the terminal pairs disposed in a line and designated as signal-signal-ground sequence. The contact pairs include a first and a second contacts substantially aligned with each other along the second direction. The first contact has a first tail portion and a first contact portion in contact with the second engaging portion of the second terminal. The second contact has a second tail portion and a second contact portion in contact with the first engaging portion of the first female terminal. The first and second tail portions of the contact pairs disposed in a line. A length of the first terminal plus a length of a corresponding mated second contact is substantially equal to a length of the second terminal plus a length of a corresponding mated first contact.

Signals transmitted through the first transmission path of the second contact and the first terminal, and the second transmission path of the first contact and the second terminal. Designing the twist transmission paths within the wafer or dielectric support allows signals travel through the high density backplane connector synchronously. It helps to reduce crosstalk by eliminating skew on the terminals or the contacts.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made to the drawing figures to describe the present invention in detail. Referring toFIG. 1, a high density backplane connector100in accordance with the preferred embodiment of the present invention comprises a first connector1connected with a mother board3via press-fit technology, and a second connector2connected to a daughter board4orthogonal to the mother board3via press-fit technology. The first connector1is adapted for mating with the second connector2to establish an electrical connection between the mother board3and daughter board4. The first connector1is shown as a female connector in view of its housing structure and will be so called in the following description. Similarly, since the second connector2is shown as a male connector in view of its interface housing structure, it will be so called in the following description for ease of reference and clarity, but not in the sense of limiting.

Referring toFIG. 11, the mother board3and the daughter board4respectively have a plurality of columns of holes defined thereon. Both the mother board3and the daughter board4are arranged with array of holes in column and row. Each column of the holes defined on the mother board3comprises a plurality of first grounding holes31and a plurality of first signal hole pairs32arranged alternately with the first grounding holes31. Each column of the holes defined on the daughter board4comprises a plurality of second grounding holes41and a plurality of second signal hole pairs42arranged alternately with the second grounding holes41.

Referring toFIGS. 2-5, the female connector1comprises a rectangular female housing19defining a receiving cavity191, a plurality of female terminal modules10received in the receiving cavity191. The plurality of female terminal modules10comprises a plurality of first female terminal modules10aand a plurality of second female terminal modules10barranged alternately with each other. One first female terminal module10aand one second female terminal module10bare shown inFIGS. 2 and 3, with other female terminal modules10left out.

ReferringFIGS. 4-5, the first female terminal module10acomprises a first female dielectric support or insulative housing11, a plurality of first female terminals12mounted on the first female dielectric support11, a second female dielectric support13, and a plurality of second female terminals14assembled to the female dielectric support13. In another embodiment, the first and second female dielectric supports11and13could be integrated into a whole. The first female terminal12comprises a first grounding terminal121and a first signal terminal122arranged alternately with the first grounding terminal121along a vertical direction. Each first female terminal12includes a first engaging portion124, a first tail portion125and a first connecting portion123connecting with the first engaging portion124and the first tail portion125. The first engaging portion124is divided into two separated branches each having an arc-like engaging face126. The second female terminal14comprises a second grounding terminal141and a second signal terminal142arranged alternately with the second grounding terminal141along a vertical direction. In conjunction withFIG. 10, each second female terminal14includes a second engaging portion144, a second tail portion145and a second connecting portion143connecting with the second engaging portion144and the second tail portion145. The second engaging portion144has a rectangular flat engaging face146. The engaging face146of the second grounding terminal141has a dimension larger than that of the engaging face146of the second signal terminal142.

In assembling of the first female terminal module10a, the plurality of first female terminals12are mounted in the first female dielectric support11firstly, with the first connecting portion123embedded in the first female dielectric support11. The first grounding terminals121and the first signal terminals122are disposed alternately with each other.

Secondly, the second female terminals14are embedded in the second female dielectric support13by insert molding or other methods, with the second engaging portion144exposed on the second female dielectric support13and the tail portion145exposed outside of the second female dielectric support13. The second grounding terminals141and the second signal terminals142are disposed alternately with each other. The second female dielectric support13defines a plurality of grooves or recesses131aligned with the second engaging portion144.

Thirdly, the first female dielectric support11together with the first female terminals12are mounted on the second female dielectric support13together with the second female terminals14to form the first female terminal module10aas a whole.

At the same time, the tail portions125and145of the first grounding terminal121and the second grounding terminal141are disposed in oppose pattern to form themselves as a grounding terminal pair17. The first grounding terminal121and the second grounding terminal141are substantially aligned with each other along a traverse direction perpendicular to the vertical direction. The tail portion125and145of the first signal terminal122and the second signal terminal142are disposed in jogged pattern to form themselves as a signal terminal pair18. The first signal terminal122and the second signal terminal142are substantially aligned with each other along the traverse direction.

The first female terminal module10ahas a mating edge101for mating with the male connector2. In each first female terminal module10a, compared to the first engaging portions124of the first female terminals12, the second engaging portions144of the second female terminals14are disposed adjacent to the mating edge101. The first tail portion125of the first grounding terminal121and the tail portion145of the second grounding terminal141are overlapped with each other (seeFIG. 12). The first tail portion125of the first signal terminal122and the tail portion145of the second signal terminal142are disposed in sequence. The tail portions125and145of all terminals in one module are substantially arranged in a line and designated as ground-signal-signal sequence.

In conjunction withFIG. 3, the second female terminal module10bhas a configuration similar to that of the first female terminal module10a, with the terminal arrangement staggered with that of the first female terminal module10afor reducing crosstalk.

Referring toFIG. 6, the male connector2comprises an L-shaped male housing29, a plurality of male contact modules20secured in male housing29. The male housing29has a plurality of latching recesses291for latching with a latching protrusion202formed on the male contact modules20. The male housing29could latch with the male contact modules20in other manners optionally. The plurality of male contact modules20comprise a plurality of first male terminal modules20aand a plurality of second male terminal modules20barranged alternately with each other. One first male terminal module20aand one second male terminal module20bare shown inFIG. 6, with other male terminal modules20left out.

ReferringFIGS. 6-8, the first male terminal module20acomprises a first male wafer21, a plurality of first male contacts or terminals22mounted on the first male wafer21, a second male wafer23, and a plurality of second male contacts or terminals24assembled to the second male wafer23. In another embodiment, the first and second male wafers21and23could be integrated into a whole. The first male contact22comprises a first grounding terminal221and a first signal terminal222arranged alternately along the vertical direction. Each first male contact22includes a first contact or engaging portion224, a first tail portion or tail section225and a first body portion223connecting with the first contact portion224and the first tail section225. The first contact portion224is divided into two separated branches having an arc-like engaging face226. The second male contact24comprises a second grounding contact241and a second signal contact242arranged alternately along the vertical direction. In conjunction withFIG. 10, each second male contact24includes a second contact or engaging portion244, a second tail section245and a second body portion243connecting with the second contact portion244and the second tail section245. The second contact portion244has a rectangular flat contact face246.

In assembling of the first male contact module20a, the plurality of first male contacts22are mounted in the first male wafer21firstly, with the first body portion223inserted in the first male wafer21. The first grounding contacts221and the first signal contacts222are disposed alternately with each other.

Secondly, the second male contacts24are embedded in the second male wafer23by insert molding or other methods, with the second contact portion244exposed on the second male wafer23and the second tail section245exposed outside of the second male wafer23. The second grounding contacts241and the second signal contacts242are disposed alternately with each other. The second male wafer23defines a plurality of grooves231aligned with the second contact portions244.

Thirdly, the first male wafer21together with the first male contacts22are mounted on the second male wafer23together with the second male contacts24to form the first male contact module20aas a whole.

At the same time, the first grounding contact221and the second grounding contact241are disposed in opposing pattern to form themselves as a grounding contact pair27. The first grounding contact221and the second grounding contact241are substantially aligned with each other along the traverse direction. The tail sections225,245of the first signal contact222and the second signal contact242are disposed in jogged pattern to form themselves as a signal contact pair28. The first signal contact222and the second signal contact242are substantially aligned with each other along the traverse direction.

The first male contact module20ahas a mating side201for mating with the first female terminal module10a. In each first male contact module20a, compared to the first contact portions224of the first male contacts22, the second contact portions244of the second male contacts24are disposed adjacent to the mating side201. The first tail section225of the first grounding contact221and the second tail section245of the second grounding contact241are overlapped with each other. The first tail section225of the first signal contact222and the second tail section245of the second signal contact242are disposed in sequence. The tail sections225,245of all contacts in one module are designated as ground-signal-signal sequence and substantially arranged in a line.

The second male contact module20bhas a configuration similar to that of the first male contact module10b, with the terminal arrangement of staggered with that of the first male contact module20afor reducing crosstalk.

Referring toFIG. 1, when the male connector2is mated with the female connector1along a mating direction orthogonal to the mother board3, the first male contact modules20aare partially overlapped with the first female terminal modules10a, and the second male contact modules20bare partially overlapped with the second female terminal modules10b.

FIGS. 9-11show the engagement between the first male contact module20aand the corresponding first female terminal module10a. The first contact portion224of the first male contact22is in contact with the corresponding second engaging portion144of the second female terminal14at a first point A. The first points A are arranged in a first line. While the second contact portion244of the second male contact24is in contact with the first engaging portion124of the first female terminal12at a second point B. The second points B are arranged along a second line. The first and second lines respectively extend along the vertical direction orthogonal to the daughter board4. The second line of the second points B is spaced apart from the first line of the first points A along the mating direction. The second point B is aligned with the corresponding first point A along the mating direction. It doesn't need to increase either the thickness of the second dielectric support13or the thickness of the second male wafer23, since the first line of the first points A and the second line of the second points B is not overlapped.

The first tail portion125of the first grounding terminal121and the second tail portion145of the second grounding terminal141are overlapped with each other to share a first grounding hole31of the mother board3. The first signal terminal122and the second signal terminal142are formed as a differential terminal pair, i.e., the signal terminal pair18, with the first tail portion125of the first signal terminal122and the second tail portion145of the second signal terminal142inserted into corresponding first signal hole pair32of the mother board3.

The first tail section225of the first grounding contact221and the second tail section245of the second grounding contact241are overlapped with each other to share a same second grounding hole41of the daughter board4. The first signal contact222and the second signal contact242are formed as a differential contact pair, i.e., the signal contact pair28, with the first tail section225of the first signal contact222and the second tail section245of the second signal contact242inserted into corresponding second signal hole pair42of the daughter board4.

The first grounding contact221and the second grounding contact241respectively electrically connect with the second grounding terminal141and the first grounding terminal121for grounding. The first signal contact222and the second signal contact242respectively electrically connect with the second signal terminal142and the first signal terminal122for transmitting differential signal.

The length of first grounding terminal121plus the length of the second grounding contact241is substantially equal to the length of second grounding terminal141plus the length of first grounding contact221. Thus, the transmission path of transmitting grounding signals through the path of first grounding terminal121and the second grounding contact241is equal to that through the path of the second grounding terminal141and the first grounding contact221. The grounding signal launched at the same time would arrive at the same time via the two paths. Similarly, the length of first signal terminal122plus the length of the second signal contact242is substantially equal to the length of second signal terminal142plus the length of first signal contact222. The differential signal launched at the same time would arrive at the same time through the second signal contact242then the first signal terminal122, and through the first signal contact222then the second signal terminal142. Designing the twist transmission paths within the wafer or dielectric support allows signals travel through the high density backplane connector100synchronously.

The grounding path and the signal path are arranged alternately in the high density backplane connector100. The ratio of grounding path and the signal path is one vs one. It helps to improve crosstalk performance. Optionally, the ratio of the signal path and the grounding path could be increased, with the crosstalk performance being unimproved.

Referring toFIG. 11, the first tail portion125of the first grounding terminal121and the second tail portion145of the second grounding terminal141share the first grounding hole31of the mother board3. The first tail section225of the first grounding contact221and the second tail section245of the second grounding contact241share the second grounding hole41of the daughter board4. Board density is not sacrificed.

Referring toFIGS. 9 and 11, in each differential terminal pair18,28, the first tail portion125of the first signal terminal122and the second tail portion145of second signal terminal142respectively orient toward opposite directions from corresponding first, second connecting portions123,143to form the first, second tail portions125,145into a “Y” shape. The first and second tail portions125,145of the first and second signal terminals122,142are arranged into a first column. The first, second tail portions125,145of the first and second grounding terminals121,141are overlapped and arranged along the first column too. The first, second tail portions125,145in a same first female terminal module10aarranged along a same column would result in space saved. The arrangement of the first and second tail sections225,245is similar to that of the first, second tail portions125,145.

The disclosure is illustrative only, changes may be made in detail, especially in matter of shape, size, and arrangement of parts within the principles of the invention.