Modular board to board connector

A connector assembly has a receptacle module and a pin module that interconnect. Stiffener engagement projections and recesses are provided along the sides of the receptacle and pin modules in an alternating fashion. The recesses are sized and shaped to receive the stiffener engagement projections of a respective neighboring module. Stainless steel elongated stiffener plates removably engage the pin and receptacle modules in both an X-direction and/or a Y-direction. The stiffener plates have slots that extend partly through the plates and align with the stiffener engagement projections and receiving recesses. The slots receive respective ones of the projections of the neighboring pin and receptacle modules.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to board to board modular connectors. More particularly, the present modular connector invention permits the modular assembly of boards.

2. Background of the Related Art

Electrical connectors are used in many types of electronic systems. For example, in many computerized systems, printed circuit boards are joined together through connectors. One piece of the connector is attached to each board. The connector pieces are mated to complete many signal paths between the boards. In addition, the DC power or ground paths are also completed through the connector. The DC paths allow the printed circuit boards to be powered and, if configured appropriately, shield adjacent signal contacts to improve the integrity of signals passing through the connector. It is generally easier and more cost effective to manufacture a system on several printed circuit boards that are then joined together with electrical connectors.

Each half of the connector contains conducting contacts held in an insulative housing. Each contact has a contact region, which makes electrical contact to a contact in the other half of the connector when the connectors are mated. In addition, each contact has a tail portion which extends from the housing and is attached to a printed circuit board. The tail could be either a solder tail, which is soldered to the printed circuit board, or a press-fit tail, which is held by friction in a hole in a printed circuit board. The contact body carries the signal from the contact region to the tail.

One common type of signal contact simply uses a pin as the contact region. Pin contacts generally mate with receptacle type contacts. The contact area of a receptacle type contact is formed from a pair of parallel-cantilevered beams. The cantilevered beams generate a spring force against the pin, ensuring a good electrical contact. Other types of contacts can also used, such as contacts shaped as plates, blades or forks.

Connector housings are often molded from plastic. Initially, connector housings were molded in one piece. However, it is difficult to maintain the necessary tolerances for large surface mount connectors subject to high temperature gradients such that building large connectors from individual modules is easier.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to provide a modular board to board connector with X and Y scalability. It is a further object of the invention to provide boards connected by a stiffener that provides scalability in both an X and Y directions.

In accordance with these and other objectives, a connector or connector assembly is provided. The connector assembly has a receptacle module and a pin module that interconnect. Stiffener engagement projections are provided along the sides of the receptacle and pin modules. Recesses are also provided along the sides of the receptacle and pin modules. The recesses are sized and shaped to receive the stiffener engagement projections of a respective neighboring module.

Stainless steel stiffener plates removably engage the pin and receptacle modules in both an X-direction and/or a Y-direction. The stiffener plates have rectangular-shaped slots that extend partly through the plates and align with the stiffener engagement projections and receiving recesses of the pin and receptacle modules. The slots receive respective ones of the projections on the sides of the neighboring pin and receptacle modules. In the X-direction, the stiffener plates extend the length of multiple modules to engage the projections of those modules.

In the Y-direction, the projections on one side of each module are offset from the projections on the opposite side of that module, so that the projections do not align with those of a neighboring module. Thus, the stiffener plate receives the projections of neighboring modules in an alternating fashion. Accordingly, the stiffeners are able to engage connectors and their respective boards in a modular fashion in both the X-direction and the Y-direction.

These and other objects of the invention, as well as many of the intended advantages thereof, will become more readily apparent when reference is made to the following description, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

Turning to the drawings,FIG. 1shows a connector or connector assembly10in accordance with a preferred embodiment of the invention. The connector assembly10has a receptacle module100and a pin module200that interconnect. The receptacle module100has an insulated housing102that extends around the outer circumference of a contact section104. The contact section104has receptacles fitted with contacts150, which are shown in the embodiment ofFIG. 1as hook-type contacts. The insulated housing102is preferably a plastic material and has a rectangular or square shape, though other suitable materials and shapes can be utilized. The housing102includes openings for receiving the contacts150of the contact section104.

The housing portion102has a first side110and a second side112opposite the first side. The housing102also has a first end140and a second end142opposite the first end140. An engagement structure comprising stiffener engagement projections114,116are provided along the first side110of the receptacle module100, and stiffener engagement projections118,120are provided along the second side112of the receptacle module100. Each side110,112of the housing102preferably has at least two stiffener engagement projections so that the module100connects to neighboring modules100toward each end140,142of the module100. However, only a single projection can be provided on each side, and more than two projections can also be used. In addition, it is possible for a projection to be utilized on only one side of the module100.

As best shown inFIG. 4, the projections114,116,118,120each have a narrow base portion132that extends outward from the face of the side wall110,112. A wide head or top portion134is connected substantially perpendicular to the top of the base portion132to form a T-shaped cross-section. As depicted, the top portion134has one end that is flat and one end that is beveled along its sides.

Returning toFIG. 1, the first side110of the receptacle module100is also provided with recesses122,124, and the second side112of the receptacle module100is provided with engagement structures comprising recesses126,128. The recesses122,124,126,128are sized and shaped to receive the stiffener engagement projections114,116,118,120. Thus, as best shown inFIG. 4, the receiving recesses122,124,126,128are formed so a first end is straight and a second end has beveled sides. The beveled sides of the projections114,116,118,120facilitate the top portion134being received by a respective receiving recess122,124,126,128of a neighboring receptacle module100. The recesses122,124,126,128preferably extend about half way into the side walls110,112, though can extend less or more or all the way through the side walls. A stand off136is provided along the sides110,112of the receptacle module100. The receptacle module100receives a printed circuit board (“PCB” or just “board”) on the side facing away from the pin module200. The stand off136controls the amount of stress the hook like leads may be subject too during the attachment process.

Referring toFIG. 2, an opening144is located at each of the first and second ends140,142of the receptacle module100. The housing102also has a recessed portion146at the bottom of the receptacle module100that engages a respective configuration of the pin module200.

The pin module200has an insulated housing202that extends around the outer circumference of a contact section204. The contact section204has receptacles fitted with contacts250, which are shown in the embodiment ofFIG. 1as pin contacts. The insulated housing202is preferably a plastic material and has a rectangular or square shape, though other suitable materials and shapes can be utilized. The housing202includes openings for receiving the contacts250of the contact section204.

The housing portion202has a first side210and a second side212opposite the first side210. The housing202also has a first end240and a second end242opposite the first end240. Stiffener engagement projections214,216are provided along the first side210of the pin module200, and stiffener engagement projections218,220are provided along the second side212of the pin module200. Each side210,212of the housing202preferably has at least two stiffener engagement projections so that the module200connects to neighboring modules200toward each end240,242of the module200. However, only a single projection can be provided on each side, and more than two projections can also be used. In addition, it is possible for a projection to be utilized on only one side of the module200.

As best shown inFIG. 4, the projections214,216,218,220each have a narrow base portion232that extends outward from the face of the side wall210,212. A wide head or top portion234is connected substantially perpendicular to the top of the base portion232to form a T-shaped cross-section. As depicted, the top portion234has one end that is flat and one end that is beveled along its sides.

Returning toFIG. 1, the first side210of the pin module200is also provided with recesses222,224, and the second side212of the pin module200is provided with recesses226,228. The recesses222,224,226,228are sized and shaped to receive the stiffener engagement projections214,216,218,220. Thus, as best shown inFIG. 4, the recesses222,224,226,228are formed so a first end is straight and a second end has beveled sides. The beveled sides of the projections214,216,218,220facilitate the top portion234being received by respective recesses222,224,226,228of a neighboring pin module200. The recesses222,224,226,228preferably extend about half way into the side walls210,212, though can extend less or more or all the way through the side walls. A stand off236is provided along the sides210,212of the pin module200. The pin module200receives a PCB on the side facing away from the receptacle module100, and the stand off236controls the stress the hook like leads may be subject to during the attachment process.

Referring toFIG. 3, the first and second ends240,242of the pin module200have upright alignment tab portions244. The housing202also has a narrowed inner portion246at the top of the pin module200that engages the recessed portion146of the receptacle module100. The narrowed inner portion246has a beveled face.

As shown inFIG. 4, the receptacle module100mates with the pin module200such that the contacts250of the pin module200electrically engage the contacts150of the receptacle module100. The tab portions244of the pin module200are slidably received in the opening144of the receptacle module100. The tab portion244and opening144pre-align the pin module200with the receptacle module100to initially align the respective contacts150,250. The top of the tabs244are tapered, so that if the bottom of the receptacle module100come into contact with them, they move inward to better align with the pin module200. The tab portions244and openings144are offset on the end walls140,142and240,242to ensure that the receptacle module100and the pin module200are properly aligned in the correct direction and position.

As the receptacle module100and pin module200come closer and the housings102,202contact one another, the narrowed inner portion246of the pin module200receives the recessed portion146of the receptacle module100, as also shown inFIGS. 17(a) and (b). The beveled face of the inner portion246facilitates alignment of the respective contacts150,250of the modules100,200. The narrowed inner portion246and recessed portion146, as well as the contacts150,250, form a snug friction fit between the modules100,200. The portions246,146also form the final alignment of the receptacle module100and pin module200and align the bottoms of the receptacle contacts150with the tops of the pin contacts250.

Further to the preferred embodiment, the receptacle module100and the pin module200each have a length of about 27.3 mm and a width of about 18.4 mm. And, there are 20 rows and 13 columns of contacts150,250. However, the dimensions and number of contacts are not intended to limit the invention. The modules100,200can have any suitable dimensions and number of rows and columns, either greater or less than the preferred embodiment, while still falling within the scope of the invention.

InFIG. 5, the modularity of the system10is shown in the X-direction. Three receptacle modules100are illustrated having an in-line configuration. Stainless steel elongated stiffener plates300,302removably engage the modules100. Though three modules100are shown in the embodiment ofFIG. 5connected by two stiffeners300,302, two or more modules100can be connected by the stiffeners300,302as suitable for a particular application. In addition, though in the preferred embodiment the stiffeners300,302extend the entire length of the three modules100, more than one stiffener300,302can be provided along each side of the modules100. Thus, for instance, two stiffeners (each about one-half the length of the stiffener300) can replace the single stiffener300. Or, two shortened stiffeners can be used, one that connects the projection118of the first (nearest in the embodiment ofFIG. 5) module100with the projection120of the second (middle) module100; and a second one that connects the projection118of the second module100with the projection120of the third (rear) module100.

In the embodiment shown, the modules100are connected in a single in-line configuration to have X-direction scalability. The stiffener plates300,302have rectangular-shaped slots310,312,314,316that extend partly through the plates300,302and align with the stiffener engagement projections and receiving recesses of the modules100,200. The slots312,316receive respective ones of the projections114,116on the first side110of the modules100. The slots310-316are slightly wider than the thickness of the base portions132,232but narrower than the width of the top portions134,234of the projections114,116. Accordingly, the base portions132of the projections114,116are slidably received in a respective slot316,312of the stiffener300. The stiffener302is likewise removably connected to the projections118,120on the second side112of the receptacle module100. Since the slots of the stiffener are narrower than the top portions134, the projections cannot pull free from the stiffener if the stiffener is pulled in a direction away from the module100.

InFIG. 6, the pin modules200are also shown in an in-line configuration. Stiffeners304,306connect the modules200together. The stiffeners300,302,304,306are all made of stainless steel, having a similar coefficient of expansion as a typical printed circuit boards (“PCB”) that connect to the modules100,200. In this way, the stiffeners300,302,304,306expand and contracts significantly the same as the PCB to maintain the system10alignment integrity under various thermal conditions providing precise surface mount contact lead to PCB pad alignment. The metal stiffeners can be made with greater accuracy than a similar sized housing can be molded.

Because the modules100,200are made from plastic and the PCB materials have a different coefficient of expansion than the modules100,200, the modules100,200and the PCBs would create an unacceptable SMT lead alignment, especially as the connector/modules become larger in size. The stiffeners300-306have substantially similar coefficients of expansion as the PCB. Thus, the modules100,200are sized to minimize the thermal expansion in the X and Y axis and are assembled to stiffeners300,302,304,306. The expansion of the connector under various thermal conditions are controlled by stiffeners300,302,304,306in the X axis. When multiple modules100,200are assembled with stiffeners300,302,303,304,306in the Y axis (FIG. 8), the stiffener engagement projection114,116,118,120and recesses122,124,126,128accommodate expansion and contractions under any thermal conditions.

FIG. 7shows the modules100,200in an in-line configuration, with the receptacle modules100connected to the pin modules200. As shown, the projections118,120and the recesses128,126of the receptacle modules100are in reverse positions than the projections218,220and the recesses228,226of the pin modules200, respectively. Thus, for instance, while the receptacle module100has a projection126located closes to the first end140, the pin module200has a recess226located closest to the first end240. Accordingly, the projections118,120on the second side112of the module100will align and mate with the mating recesses122,124on the first side110of a neighboring module100in the Y-direction. And, the projections114,116on the first side110of a module100will align and mate with the mating recesses126,128on the second side112of a neighboring module100in the Y-direction.

In addition, the stiffeners300,302of the receptacle modules100are inverted with respect to the stiffeners304,306of the pin modules200. Thus, the slots310,312,314,316of all the stiffeners300,302,304,306face outward, i.e., in the embodiments shown, the slots on the top open upwardly and the slots on the bottom open downwardly. In that manner, the stiffeners300,302,304,306cannot be removed from the modules100,200while the receptacle modules100are connected to the pin modules200. Yet, the individual modules100,200can be separately added to or removed from the stiffeners and repaired or replaced, if necessary.

It should be appreciated, however, that the stiffeners, engagement projections and their receiving recesses could be readily configured so that the individual modules100,200cannot be removed unless the entire stiffener connecting all the modules is removed. It should further be noted that the stiffeners300,302are identical to each other. Namely, the slots in each of the stiffeners300,302are at the same position along the stiffeners. Thus, the stiffeners are interchangeable with one another, which reduces cost of manufacturing and ease of use.

InFIG. 8, four receptacle modules100are connected in a 2×2 quad configuration to illustrate the X and Y scalability of the invention. Three stiffeners300,302are provided to connect the modules100. Because the projections118,120and recesses126,128along the first side110of the modules100are reversed with respect to the projections114,116and recesses122,124along the second side112of the modules100, a single stiffener303is utilized to connect the modules100to one another in the Y-direction (best shown inFIG. 10). Additional modules100can be connected to the unused slots310,314of the stiffeners300,302to further expand the configuration in the Y-direction. The figure further illustrates the use of the stiffeners300,302,303connecting two modules100in the X-direction. It should be appreciated that any number of modules can be connected together to form arrays of different dimensions as suitable for a particular application, within the scope of the present invention. The invention is most useful, however, in the preferred embodiment where there are at least two modules in each of the X and Y directions, i.e., the quad configuration shown.

FIG. 9illustrates four pin modules200connected in a 2×2 quad configuration andFIG. 10illustrates the quad receptacle modules100ofFIG. 8connected to the quad pin modules200ofFIG. 9.FIG. 10shows the projections of the receptacle modules100engaged in the mating recesses of the neighboring receptacle modules100in the Y-direction.

The invention can also be used to connect modules having smaller dimensions than the receptacle and pin modules100,200ofFIGS. 1-10, or to connect modules of different sizes and shapes. For instance, the invention can be utilized with the modules400,450shown inFIGS. 11-14. In addition, the modules400,450are power modules that are especially useful to connect with the receptacle and pin modules100,200because the power modules400,450provide the power necessary to drive and operate the receptacle and pin modules100,200.

FIGS. 11-14show that the power modules400,450each have a projection402,452along each of two opposing sides. The power module400(FIGS. 11-12) is utilized to provide power to one or more pin modules200, and the power module450(FIGS. 13-14) provides power to one or more receptacle modules100. The top of the pin power module400has a ledge404forming a tab406. The bottom of the receptacle power module450has a downwardly extending sidewall454having a beveled inward face456.

InFIG. 15, the receptacle power module450is connected to the pin power module400. The ledge404of the pin power module400receives the downward extending sidewall454of the receptacle power module450. Thus, the tab406of the pin power module400is received within the sidewall454of the receptacle power module450. The beveled face456facilitates connection by pre-aligning the power modules400,450with each other prior to connection.

As illustrated in the embodiment shown, the combined power modules400,450are positioned adjacent to the modules100,200so that the power module projections402,452are aligned with the projections118,218of the modules100,200. A stiffener (not shown) can then be connected to the power modules400,450and to the receptacle and pin modules100,200. The power modules400,450can connect to one of the standard slots located in the stiffener. Or, an additional slot(s) can be provided in the stiffener to accommodate one or more modules that may have different spacing requirements for the slots, such as the power modules400,450of the present embodiment. One or more sets of power modules400,450may be provided for one or more receptacle and pin modules100,200. For instance, the quad configurations ofFIGS. 8-10can be provided with up to 4 sets of power modules400,450, i.e., one for each receptacle and pin module100,200.

As has been shown, the invention provides X and Y scalability for flexibility in expanding module connections, replacing or repairing damaged modules, and is configurable to meet signal density needs. The stiffeners also reduces coefficient of expansion mismatch between PCBs and pin and receptacle modules. This is especially important during re-flow where the heating and cooling at different rates than solder creates stress due to the mismatch in the coefficient of expansion. Additionally the design of hook like lead having a level of compliancy further reduces the stress transferred to the solder joint. Though the invention is illustrated in the figures with single ended contacts, it can also be utilized for differential contacts.

Further to the preferred embodiment, the modules100,200are each approximately 24 mm long by about 15 mm wide, and the stiffeners300-306are each about 44 mm long, 2 mm wide, and about 0.5 mm thick. However, any suitable size and shape modules and stiffeners can be utilized without departing from the spirit and scope of the invention.

The foregoing description and drawings should be considered as illustrative only of the principles of the invention. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.