GB2316550A

GB2316550A - PCB-mounted SMT connector

Info

Publication number: GB2316550A
Application number: GB9717270A
Authority: GB
Inventors: Wilhelmus Johannes Brummans
Original assignee: Whitaker LLC
Current assignee: Whitaker LLC
Priority date: 1996-08-15
Filing date: 1997-08-14
Publication date: 1998-02-25
Also published as: GB9717270D0; GB9617178D0

Abstract

An electrical connector (30)is mountable in an opening (4) along an edge (6) of a printed circuit board (2) having mounting holes (16) and contact pads (18) disposed adjacent the opening. The connector includes a connector body (32) having a connector receiving end (34). A plug receiving cavity extends into the body from the connector receiving end (34) in order to receive a mating modular plug and the body (32) is sized to be received in the opening (4). A plurality of contacts (46) are contained in the body, these contacts being accessible in the cavity to the mating plug and including tails (48) extending from the body for electrical connection with the contact pads (18) of the PCB. Mounting members (52) extend from the body to position the connector on the printed circuit board. The body is receivable in the opening (4) as a single unit, the mounting members including positioning pins (58) sized to fit in the mounting holes (16), thereby limiting displacement of the connector body relative to the PCB, and the contact tails (48) are configured for surface mount soldering.

Description

LOW HEIGHT MODULAR JACK RECEPTACLE The present invention relates to an electrical connector and in particular to an electrical connector known as a modular jack receptacle in common use within the telephone industry.

In the communication industry there is widespread use of an electrical connector called a modular jack used to receive a modular plug therein. These connectors are used for voice and data transmission. The connector incorporates a body portion having a cavity therein where a plurality of resilient contacts are disposed for engaging contacts of the mating plug when the plug is received in the cavity. U.S.

patent 4,734,043 discloses a modular jack receptacle of the aforegoing type adapted to be mounted upon a printed circuit board. The surface of the body that corresponds to the printed circuit board includes mounting posts that would extend through openings in the printed circuit board for locating the connector thereupon. Furthermore, the contacts within the body have tail portions configured to be connected to circuit traces on the printed circuit board. It is known to use these tail portions either in a through-hole mounting manner or in a surface mount soldering manner. A problem with a modular jack receptacle such as this is the height required above the printed circuit board to accommodate both the contacts within the body and the mating plug is relatively large. In many applications, as packaging density has increased and new low profile connectors and components have been incorporated onto printed circuit boards, the height of this connector may become a limitation on packaging.

U.S. patent 4,915,655 discloses a modular jack receptacle connector configured to address this height problem. The connector disclosed comprises of a two-part body where the contacts are disposed in the first part which has a front end where a portion of the plug receiving hole is disposed and an open bottom. Mounting members extend out of the first part and are received in openings in the printed circuit board for retaining the first half therewith. The mounting members further define the plane in which the body is mounted on the printed circuit board which is substantially flush with the printed circuit board so that only a portion of the height required for the plug is above the board. The terminals are disposed in the first part and are then automatically soldered to the printed circuit board.

After soldering, a portion of the printed circuit board below the open bottom of the first part is broken out. The resulting opening is then closed by a separate cover member such that the cavity wherein the plug connector is to be received is completely defined with portions both above and below the printed circuit board.

U.S. Design Patent 351,136 discloses a communications connector for mounting in an opening along the edge of a printed circuit board by way of surface mount techniques.

This connector is of a low-height construction, whereby the connector is suspended in the opening. The locating members are formed on a shield member which is stamped and formed from sheet metal. The stamping and forming process, along with the assembly process, leads to inaccuracies which make it difficult to fix the connector accurately to the board.

While the connectors described above do address the problem relating to the height above the board of the connector body, a number of other problems remain. First, the connector disclosed utilizes contacts adapted to be received in through-holes in the printed circuit board. It would be desirable to utilize contacts that could be surface mount soldered upon the printed circuit board. Furthermore, in high volume assembly operations where surface mount soldering is advantageously used, the printed circuit boards usually are automatically assembled by way of pick-and-place assembly tools. It would be difficult to utilize such assembly techniques in an economical manner with the connector disclosed above in light of the numerous secondary operations that are required, such as breaking out a portion of the printed circuit board and mounting the cover thereafter.

Finally, where surface mount soldering is to be used there is the possibility that any strain exerted as a result of mating and unmating the plug connector or that which is passed through by the cable connected to the plug connector would detrimentally effect the electrical connection formed by surface mount soldering.

Therefore, it is an object of this invention to provide an electrical connector of the modular jack receptacle type having a low height above the board that is particularly suitable to surface mount soldering and will allow pick-andplace assembly operations without the need for secondary assembly operations and provide for protection of the electrical interface between the surface mount contacts in the connector and the printed circuit board contact pads by isolating strains relating to the mating connector interface and transferring those strains into the printed circuit board separately from the surface mount interface.

These and other objects are accomplished by providing an electrical connector mountable in an opening along an edge of a printed circuit board where mounting holes having a particular configuration and contact pads are disposed adjacent the opening, the connector comprising: a connector body having a connector receiving end, an opposite end, opposing sidewalls therebetween, a top wall and a bottom wall connected to the sidewalls, the connector receiving end and the opposite end, where a plug receiving cavity extends into the body from the connector receiving end in order to receive a mating modular plug and the body is sized to be received in the opening; a plurality of contacts contained in the body where the contacts are accessible in the cavity by the mating plug and include a tail extending from the body for electrical connection with the contact pads of the PCB, and a mounting member extending out of the body to position the connector on the printed circuit board, the connector being characterized in that: the body is receivable in the opening as a single unit; the mounting member is integrally moulded as part of the housing and includes a positioning pin sized to be closely received in the mounting hole thereby limiting displacement of the connector body relative the PCB: and the contact tails are configured for surface mount soldering.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a partially exploded perspective assembly view of an electrical connector according to the present invention; and Figure 2 is a side assembled view of the assembly of figure 1 showing the electrical connector mounted upon a printed circuit board.

With reference first to figure 1, a printed circuit board is representatively illustrated at 2. The printed circuit board 2 includes an opening 4 extending inward from a front edge 6. The opening 4 is defined by opposing side edges 8 and a back edge 10. Adjacent the opening 4, in this embodiment, along each of the side edges 8 is a mounting hole 16. For ease of manufacture, these mounting holes 16 may be made round and formed by a drilling or punching operation without difficulty. A plurality of contact pads 18 are also disposed adjacent the opening 4 along the rear edge 10. These contact pads 18 are connected to circuit traces 20 that are common in printed circuit board fabrication. The contact pads 18 are disposed on an upper surface 22 of the printed circuit board 2 and includes sufficient solder material for surface mount soldering. iNdvantageously, the printed circuit board 2 may be prefabricated to this degree before further l)rocessing.

With further reference to figure 1, a connector according to the present invention is shown generally at 30.

The connector 30 includes a body 32 having a cnnnector receiving end wall 34 and an oppositely disposed end wall 36. The connector receiving end wall 34 and the opposite end wall 36 are interconnected by opposing sidewalls 38 and opposing top and bottom walls 40 and 42 respectively. A plug receiving cavity 44 extends into the body 32 from the connector receiving end 34, as best seen in figure 2. The plug receiving cavity 44 is configured to receive a standard mating modular plug (not shown) as is weil known in the art.

A plurality of contacts 46 are contained in the body 32 and include tails 48 extending out of the body for mating with the solder pads 18. In this embodiment, the tails 48 extend out of the opposite end wall 36. A forward end 50 of the contact 46 is accessible within the plug receiving cavity 44. The contacts 46 may either be over moulded in the body 32, stitched therein, or disposed in a carrier that is assembled into the body 32.

Disposed along the body 32 are a pair of mounting members 52. In this embodiment, the mounting members 52 are oppositely disposed on each of the sidewalls 38 and are similarly configured. The mounting members 52 include a first pylon 54 having a lower surface 56 for establishing a plane coincident with the top surface 22 of the printed circuit board 2 when the connector 30 is mounted thereupon. Extending from the lower surface 56 is a positioning pin 58 sized to be closely received in the mounting hole 16. In this embodiment, the positioning pin 58 is a solid pin. I-lowever, it may be desirable to provide some compliance to the pin 58 to accommodate manufacturing inaccuracies of the mounting holes 16. In addition, it may be desirable to provide second pylons 60 having a lower surface 62 that is co-planer with the lower surface 56 in order to further stabilize the connector 30 upon the printed circuit board 2 when received thereupon (figure 2).

With reference now to figure 2, the connector 30 is shown mounted in the opening 4 of the printed circuit board 2. The sidewalls 38 fit between the edges 8 and the tails 48 of the contacts 46 are seated upon the contact pads 18. The lower surfaces 56 of the mounting member 52 and the lower surface 62 of the pylon 60 are seated upon the upper surface 22 of the PCB 2 in order to establish a plane in which the connector 30 is mounted. In this position, the upper surface 22 of the printed circuit board 2 can be seen to "bisect" the plug receiving cavity 44 such that a portion of the cavity 44 is above the upper surface 22 and a portion of the cavity 44 is below the upper surface 22.

As the pins 58 are received within the mounting holes 16 as a result of a straight insertion perpendicular to the printed circuit board 2, as best seen in figure 1, and the solder tails 48 are brought in abutting contact with the solder pads 18 simultaneously, the connector 30 described above is especially suitable for pick-and-place assembly onto a prefabricated printed circuit board 2. Additionally, as the pins 58 are closely received in the mounting holes 16 any strain components in the direction of arrows A or B (figure 2) are transferred directly into the PCB 2 such that the contact pad 18 and contact tail 48 interface is protected.

Finally, as the connector 30 according to the present invention is assembled into a single unit prior to mounting on the printed circuit board 2. The connector 30 has the contacts 46 included therein and any positioning features such as the mounting member 52 or the second pylon 60 may be integrally moulded as a component of the body 32. This single assembly eliminates the need for costly and time consuming secondary operations to complete assembly of the printed circuit board with respect to the connector 30.

Claims

1. An electrical connector mountable in an opening along an edge of a printed circuit board having one or more mounting holes and a plurality of contact pads disposed adjacent the opening,comprising a connector body for fitting in the opening and having a connector receiving end wall, a plug receiving cavity extending into the body from the connector receiving end wall in order to receive a mating modular plug, a plurality of contacts mounted in the body, said contacts being accessible in the cavity to the mating plug and including tails extending from the body for electrical connection with the contact pads of the PCB, said contact tails being configured for surface mount soldering, and one or more mounting members extending from the body to position the connector body on the printed circuit board and within the opening, the or each mounting member including a positioning pin for fitting in a cooperating mounting hole thereby limiting displacement of the connector body relative the PCB.

2. The electrical connector of claim 1, which is configured as a modular jack receptacle.

3. The electrical connector of claim 1 or 2, including at least one pylon extending from the body and having a lower surface coplanar with the lower surface(s) of the mounting member(s).

4. The electrical connector of claim 3, wherein the or each pylon is disposed on the same wall surface of the body as a mounting member.

5. The electrical connector of any one of the preceding claims, wherein the contact tails extend from a wall of the body other than one on which a mounting member is disposed.

6. An electrical connector constructed substantially as hereinbefore described with reference to the accompanying drawings.