WO2014146134A1

WO2014146134A1 - Electrical connector with improved clamping mechanism

Info

Publication number: WO2014146134A1
Application number: PCT/US2014/031128
Authority: WO
Original assignee: Neoconix, Inc.
Priority date: 2013-03-15
Filing date: 2014-03-18
Publication date: 2014-09-18

Abstract

An electrical connection system with electrical contacts held in place with a releasable clamp assembly. The clamp includes a base portion which is secured to a portion of one member containing electrical contacts (such as a printed circuit board) and includes a cover portion which fits over the other member containing electrical contacts (such as an electrical connector) to provide a compressive force on the mated members, bringing and maintaining the electrical contacts into electrical connection.

Description

ELECTRICAL CONNECTOR WITH IMPROVED CLAMPING

MECHANISM

Cross Reference to Related Patents

The present patent application is a non-provisional patent application based on our prior provisional patent application, Serial No. 61/800,652 filed March 15, 2013 and entitled "Electrical Connector with Improved Clamping Mechanism". The benefit of the filing date of the provisional patent application is claimed. The specification and drawings from that prior patent application are incorporated herein by reference.

The present invention is also related to prior patents and patent applications assigned to Neoconix, Inc., the assignee of the present invention. These patents include, but are not limited to, United States Patents 8,641,428 to D. N. Light et al. for "Electrical Connector and Method of Making It"; 8,584,353 to J. D. Williams for "Method of Fabricating a Contact Grid Array"; 7,758,351 to D. D. Brown et al., for "Method and System for Batch Manufacturing of Spring Elements"; and 7,645,147 to L. E. Dittmann for "Electrical Connector having a Flexible Sheet and One or More Conductive Connectors". The specifications and drawings of these Neoconix patents are specifically incorporated herein by reference. Background of the Invention

Field of the Invention: The present invention relates to electrical connector assemblies, and, more specifically, an improved system and method for securing and clamping an electrical connector in a mated relationship with external circuit elements in a desired position and orientation to enable electrical interconnection to the external circuit elements.

Background Art: Separable electrical connectors are common in many electrical and electronic devices. They aid in manufacturing, test, and assembly of these electronic devices, and often allow rework and repair after assembly. Some separable electrical connectors interconnect rigid printed circuit boards (PCBs) to other rigid printed circuit boards. Others connect flexible printed circuits (FPCs) to rigid or flexible PCBs. Still others may connect wires or shielded 'coaxial' wires or optical communications devices to PCBs. Many times, these electrical connectors require normal force to be applied during connector actuation to 'mate' the connector— i.e., to make the electrical and mechanical

interconnection. In some cases, these connectors latch into place, and do not require maintenance of the vertical force to achieve the interconnection during product use, but can benefit from normal force as it may prevent unwanted separation or un-latching of the connector due to external forces, such as shock forces from dropping an electronic device. In some of these connectors, the retention is maintained through lateral force between two sets of springs, as in a two piece, 'male-female' connector, such as a mezzanine board to board connector. In other cases, normal force must be maintained during the life of the interconnection, as is often true for 'ZIF' connectors connecting FPCs to PCBs, as well as for many sockets for integrated circuit packages, including 'pogo pin' sockets, and other connectors where a separable electrical interconnection is made by a compliant, conductive element such as a metal spring, or by a rigid element such as a sharp pin, a fuzz button, or a dendritic pad, to a flat landing pad (such as a Land Grid Array pad (LGA)) on a printed circuit structure using normal force. Commonly, in these cases, the clamping force is applied by the same structure that comprises the structural body of the connector, and which also provides the alignment of the connector, as well as the initial actuation of the connector. When a single structural element is required to perform many differing functions, as in the connectors just described, this often requires design and material compromises whereby none of the necessary individual functions are provided optimally, and/or other compromises necessarily result, such as in size (resulting in a larger connector footprint or greater connector thickness), performance (reduced signal integrity, reduced bandwidth, and/or reduced current capacity), increased cost, etc.

In some connectors, compliant spring contacts on the connector mate to correspondingly located circuit pads on the printed circuit structures. In some such connectors, an array of spring contacts emanates from the surface of the connector, or from a planar layer below the surface which is parallel to the surface. In connectors where the compliance of spring contacts exists predominately normal to the plane of the corresponding mating pads (PCB or FPC surface), this pressure must be applied and maintained during the life of the electrical interconnection, with sufficient force to achieve acceptably low contact resistance, as well as to ensure there is no electrical interruption throughout normal product handling including drop or vibration. In portable electronics, 'normal handling' can include stringent and demanding criteria such as high shock forces (e.g., simulating product drop) which is sometimes tested to 1500g or more, as well as vibration, thermal cycling, high humidity, corrosive environments, and extended high temperatures. Some of these connectors, such as the Neoconix PCBEAM™ connector, are single piece connectors. These single piece connectors can have one side surface mounted to a PCB or flexible printed circuit with solder, to mechanically and electrically connect them to that printed circuit structure, and may have surface-emanating springs on an opposite surface which will engage mating pads on another printed circuit structure, such as a rigid PCB; a given spring location on one surface of the connector will commonly be aligned and electrically connected to a corresponding solder connection on the opposite surface of the interposer. Alternatively, these single piece connectors can have contact springs emanating from both surfaces, and can separably mate to pads on both printed circuit structures or circuit elements that are being interconnected. A given spring on one surface of the connector would typically be electrically connected to a corresponding spring in the same x,y position on the opposite surface of the connector, although PCBEAM™ technology allows for redistribution or reassignment of pin locations from one side to the other, as well as pitch translation from one side to the other.

Miniaturized electronics applications often require fine-pitch connectors, where the contact springs are closely spaced, to minimize the area required for the connector. Space-efficient clamping mechanisms which apply uniform, relatively constant compression force normal to the printed circuit surface for the life of the system are also critical in miniaturized applications. These clamping mechanisms must provide sufficient compression force to achieve low contact resistance on every contact, including overcoming any co-planarity issues on the mating printed circuits, and must provide sufficient retention to ensure the product performs consistently during normal product use with no failures during expected product life. They must also accommodate any tolerances in the size or thickness of the connector, FPC, stiffener, and any other structural elements in the path of the applied force in the assembly that is being clamped. They should also provide sufficient resistance to the shock and vibration forces from normal handling of mobile electronic devices, including dropping of the devices. Normal (vertical) force connector springs tend to provide better resistance to shock and drop forces when the total mechanical displacement during the compression of the spring is larger, and when the spring is maximally compressed within its elastic range. Thus, one objective of a clamping mechanism for these connectors might include maintaining all of the connector springs in a fully compressed state during the life of the product.

As mentioned, it is desirable that connector clamping structures would also have features providing alignment of the connector to the mating printed circuit structures, to ensure the spring contacts mate accurately on the appropriate mating pads on the circuit structures, in addition to applying sufficient compression force to fully actuate the connector. In connectors where a majority of the spring compliance exists in a direction approximately parallel to the plane of the PCB surface, many of which are two piece connectors such as 'mezzanine' connectors, a first connector piece may have spring elements which wipe against spring elements in a second connector piece, creating a displacement of the springs outwardly in one connector piece and inwardly in the other connector piece. This force can result in a low resistance contact between the two connector pieces, each of which may have been surface mounted to a respective printed circuit structure, using solder as an electrical and mechanical interconnection means. The friction resulting from this force between mating spring elements, which may possibly be bolstered by notches or bends in the springs which align and 'latch' at full engagement, provides retention force for these connectors. However, this friction-induced retention is not positive, and is known to fail under conditions of rapid deceleration, such as forces from drop, shock, or vibration of the product. In fact, these connectors are separated for repair or rework simply by pulling apart the two halves of the connector and overcoming the frictional force of the springs induced by the lateral spring force between them. Hence, these two piece electrical connectors in portable electronic systems may also require a space-efficient, secondary clamping mechanism which applies uniform, constant compression force normal to the printed circuit surface for the life of the system, in order to provide secondary retention to these friction mated, two piece connectors to ensure there is reduced probability failure during product life from, for example, shock forces from drops, etc. In these two piece connectors, the spring contact elements are often required to provide function in addition to electrical interconnection— they also may be required to provide the lateral forces that 'wipe' through any contaminants to provide low contact resistance, as well as provide the lateral retention forces after mating that keep the two halves of the connector together, and may serve to assist in alignment of the two connector halves to each other during mating. Further, the spring contacts typically terminate in solder 'tails' that allow surface mounting of the connector onto a circuit element such as a PCB. Hence, the contact element frequently provides at least three functions. General mechanical principles dictate that in the case of laterally mating spring pairs with corresponding bends or notches to aid retention, the force between the springs during the mating process peaks before the connector is fully actuated, and then decreases until mating is complete. This can result in a higher than desired contact resistance in many cases. Springs with these retention features also require complex forming shapes, which can require costly tooling and dies as well as expensive processing. Further, the forces required sometimes dictate thick spring material stock, which adds cost and weight. The complex shapes also require longer total contact length, often adding material cost and increasing inductance and cross talk, degrading signal integrity at high signal speeds. Further, the relatively long solder tails can act as an 'antenna', launching electromagnetic radiation that can interfere with other elements within or outside of the system.

A third type of connector in miniaturized electronic systems, commonly known as a zero insertion force or ZIF connector, is actuated by compressing pads on a flexible printed circuit against spring elements in the connector body using a cam-actuated lid. These lids also do not have positive retention, and can open unexpectedly due to shock or vibration, causing system level failure. Hence, these ZIF connectors may also require a space-efficient, secondary clamping mechanism which applies uniform, constant compression force normal to the printed circuit surface for the life of the system, in order to provide secondary retention to these cam actuated connectors to ensure there is no failure during product life. In these ZIF connectors, the cam actuated lid is held in the retention position by the force of the contact springs. In addition, the contact springs also end in solder tails, as with the mezzanine connectors. The same trade-offs, caused by requiring individual structural elements of the connector to fulfill multiple functions, results in compromises whereby performance is sub-optimal, size and cost may be excessive, and functional failure may occur.

Prior art, miniaturized board-to-board and flex-to-board electrical connectors often utilize the electrical contact springs of the connector not only to provide the compliant, separable electrical connection, but also as integral components of the alignment and/or clamping mechanisms for the connector. In a ZIF connector, which is typically soldered onto a printed circuit board, one end of a separate flexible printed circuit (FPC) structure is inserted into the one piece connector, which includes the contact springs, alignment mechanisms, and compression and latching (retention) mechanism. Typically, the FPC is inserted using the sides of the FPC and/or a stiffener mounted on the FPC to laterally guide it into the ZIF connector; and the FPC is inserted until the end of the FPC and/or the edge of the stiffener contacts the back of the connector. In this manner, the FPC is aligned with the contact springs. The inside of the connector body, and the outside dimension of the mating end of the FPC or its stiffener, provides alignment between the FPC and the ZIF connector, but the alignment is only as good as the molding tolerances for the housing coupled with the outline tolerance of the FPC and/or stiffener, and the alignment tolerance of the pads on the mating PCB to the outer dimensions of the flex and/or stiffener. When the cam-actuated lid is closed, compressing the FPC against the contact springs in the connector, the opposing force to the cam, which prevents its re-opening, is provided by the upward force on the FPC provided by the same electrical that form the compliant, separable electrical connection to the FPC. Hence, the spring contact elements are being required to provide multiple functions: low resistance, compliant electrical interconnection to the mating pads on the FPC, SMT solder tails for interconnection to the PCB, retention of the flex to the connector through vertical force of the springs (increasing the frictional forces on the flex), and prevention of opening of the cam-driven lid through vertical pressure on it.

In these ZIF connectors, the prior art FPC can be easily misaligned with the connector— it can be inserted at a lateral or vertical angle, possibly damaging the flex or the connector springs, or it can be incompletely inserted at the time when the lid is closed. The lid can be incompletely shut, due to operator error or due to the improper FPC insertion, and can fail to retain the connection throughout product life. The connector body likewise is required to provide multiple functions. It provides overall structural integrity to the connector. It holds the spring elements in the correct positions. It provides alignment mechanism for the inserted flex. It provides the retention mechanism via the cam-driven lid and the resultant force applied through the FPC to the contact springs. As a result, it cannot be fully optimized for any of these individual functions, and compromise results.

In one type of prior art mezzanine board-to-board connector, male and female halves of the electrical connector must each be surface mounted to a separate circuit element (e.g. one to a rigid PCB, and the other to a FPC), and then the two halves aligned and mated together at system assembly. The male half of the two piece electrical connector contains an insert or tab that is aligned with the inner dimension of an opening in the female half of the connector which is comparably sized to the tab. When pressed together, the springs in the male half of the connector are forced between springs in the female half of the connector. While the mezzanine connector is a two piece connector, both pieces each contain contact springs and alignment mechanism features and retention features. Hence, the individual functions of compressible, electrically conductive contact springs, alignment, actuation, and retention, are all embedded into each half of the connector, and often one structural component of the connector provides more than one function. For this reason, each unique functionality is compromised by combining many or all of these functions into a single structure.

In portable electronics applications, space is at a premium, and electrical connectors and their mounting hardware must be miniaturized in order to achieve acceptable product size, profile and weight.

Other limitations and disadvantages of the prior art electrical connectors will be apparent to one of ordinary skill in the art in view of the teachings of this document and the illustrations in the

accompanying drawings.

Summary of the Invention

The present invention overcomes the limitations and disadvantages of the prior art. A clamping and retention system for an electrical connector is disclosed which can provide primary or secondary compression force for separable electronic connectors of a variety of types, including mezzanine board to board connectors, ZIF connectors, normal force connectors like PCBeam™ connectors and some sockets, as well as other connector types. The disclosed clamping and retention system also can provide alignment of the connector to the mating circuit element(s). It provides approximately uniform clamping pressure across the connector area, and positive retention which resists separation which otherwise may result from rapid and/or cyclic deceleration such as from drop, shock, and vibration. This clamping and retention system is applicable to many single piece and two piece electrical connectors, and is applicable to connectors with surface emanating contacts actuated vertically with respect to the mating surface of a corresponding circuit element, such as the PCBeam™ family of connectors. It can provide significant advantages over alternative systems, including, but not limited to, the following advantages:

1 Positive retention and high resistance to release from shock or vibration, and where the retention is not reliant on the spring properties of the electrical contacts in the connector

2 .Visual, auditory and tactile cues which signal correct actuation (for example, by making a click), and can prevent incorrect actuation

3 Positive connector locating features for accurate placement of the connector with respect to mating pads on the printed circuit structures

4 Easy to assemble, with Single piece clamping structure with hinged lid, or two piece clamping structure with separable lid, or two piece clamping structure where the lid is integrated into a stiff ener on one of the mating printed circuits, or a single piece clamping structure where no lid is required, for example where the clamp applies retention force through a feature on the connector, such as an edge tab

5 Compatible with automatic 'pick and place' machines for surface mount attach of the clamp to the printed circuit structure using solder or adhesive or screws other attachment methods 6 Corrosion resistant clamp materials for use in harsh environments

7 High yield-strength clamp materials that exceed the combined compression force of the connector springs, to maintain constant compression force and maintain the connector's electrical spring contacts fully compressed throughout the product life

8 Creep resistant clamp materials for long life and consistency of spring force

9 Significant tolerance to variations in Z-height and/or thickness of the connector body, flexible printed circuit, stiffener, and other elements which may be compressed as a unit within the clamp structure

10 In some cases, the clamping and retention system disclosed can provide substantial EMI

(electromagnetic interference) shielding of the electrical interconnection for high frequency applications and/or applications sensitive to stray electromagnetic radiation.

This clamping and retention structure of the present invention is able to provide the above advantages, in part, by providing many of the above defined functions with separate, individually optimized structures or sub- structures for each individual function, thereby minimizing design compromises and maximizing performance while maintaining a small footprint and low profile interconnect structure compatible with miniaturized, portable electronic devices. The separation of functions into distinct connector structures avoids many of the design compromises inherent in other connector systems.

The present invention is a connector clamping structure that separates the various functions of: low resistance, compliant, separable electrical interconnection from elastic, conductive spring contacts; alignment to mating circuit element; connector structural integrity; spring contact position alignment and support; connector actuation; application and maintenance of force to realize contact spring compression; and clamping retention; into two or more distinct structural elements.

In one embodiment of the present invention, the compliant and separable electrical interconnection, which allows electrical signals and power to pass between circuit elements when connected, is accomplished in a single piece interposer, such as the PCBeam™ connector or other normal force one piece connectors. The interposer can have spring elements on one side or both sides. If spring elements are on one side, the other side can be directly attached to a circuit element by, for example, solder, electrically conductive adhesive, metallurgical joining, thermocompression or thermosonic bonding, wire bonding, or by other methods. The connector 'interposer' provides the structural body of the connector, which provides structural integrity, and maintains the compliant spring contact elements in the proper location and configuration. The functions of alignment and compression of the springs and retention of the compression forces, are accomplished by a separate structure, which might in common parlance be called a clamp, a clamping structure, an alignment and clamping structure, or an alignment, clamping and retention structure. In the present invention, this clamping structure separates the multiple required functions for this device (alignment, actuation, compression, retention, etc.) intoseparate structural features or elements. It typically includes a mechanism for guiding the connector (also known as interposer) into a properly aligned position so that the interposer contact springs mate accurately with mating pads on the circuit structure; a mechanism for temporary retention of the interposer and flex assembly within the clamping structure until it is actuated; a mechanism for applying compression force to effect the low resistance electrical connection; a latching mechanism to retain the assembly in its fully compressed state; and structural elements than enable release of the latching mechanism only deliberately, when rework is required. In this embodiment of the invention, the interposer is typically mated in a vertical direction, normal to the surface of the interposer and the mating circuit element. Rigid and/or flexible, generally vertical members in the clamping structure guide the connector into position. These members may guide the interposer alignment by contacting it on one or more edges, or there may be holes in the interposer that are guided by one or more vertically oriented tooling pins, or some combination of the two. In the case of alignment guides such as tooling pins, the features on the interposer that are guided by the pins may be full holes within the body of the interposer, half holes along an interposer edge, quarter holes in an interposer corner, slots, or some combination of these elements. In some cases, connector alignment to mating circuit elements may be accomplished by a combination of edge alignment guides and tooling pins.

In the case of edge guides, one or more of the guides may be composed of elastic materials with a fairly high tensile and yield strength (such as spring steel, beryllium-copper alloy, phosphor bronze, etc.). In one embodiment, two adjacent edges of the interposer are guided by vertical members designed to flex and provide spring force in a lateral direction against the interposer edges. In this embodiment, the distance between opposite edge guides may be slightly less than that dimension of the connector, resulting in a tight fit such that these springs apply pressure to two of the connector's edges to press the opposite connector edges against more rigid vertical members that function as a hard stop and precise locator for the connector to be aligned to. In this instance, the upper edge of the edge guides may be canted outward, to provide lead-in and enable easy insertion of the connector into the clamping structure.

One advantage of this alignment scheme for a connector that is actuated in a vertical direction such as the PCBeam connector, is that there is no required 'keep-out' area on the circuit structure in front of or adjacent to the connector, as is required with many laterally- aligned and inserted connectors such as low profile ZIF connectors, and hence has the advantage of a vertically actuated mezzanine board to board connector in not 'wasting' board real estate where otherwise, active or passive components or other mechanical elements could be mounted. In the present invention, the vertically oriented alignment guides can be made of thin, high strength material, such as sheet metal steel, and hence take up minimal real estate, as compared to vertically actuated board to board connectors such as mezzanine which are comprised of thick-walled, injected molded materials to accomplish alignment and to hold the springs in position in the connector.

The alignment mechanism described above also can provide temporary retention of the connector / interposer. The lateral spring pressure provided by the elastic alignment features against the interposer, which bias it against the more rigid alignment features opposing them, supplies sufficient friction so that the connector is not easily displaced from the alignment features during assembly. The alignment features can be designed to have a 'lead-in' such that the connector can be 'rough aligned' and partially inserted before contacting the alignment features. The alignment features can be of sufficient height that the connector is well-aligned before the contact springs make contact to the mating pads, so no lateral forces are applied to the springs during insertion and actuation, preventing damage to the springs.

Because these lateral edge alignment elements are providing only the functions of alignment and temporary retention, their design can be optimized for these functions, so that alignment and temporary retention can be optimized in a minimum footprint area, and the structure and the assembly process can be simple and low cost. In typical two piece mezzanine connectors, alignment is provided by the body of the connector (the injection molded plastic housings), which also provide structural support to the connector, maintain the springs in position accurately, and insulate adjacent spring contacts from one another. This multi-function nature for the connector elements compromises performance and function, while also increasing size and thickness.

In the present invention, the compression mechanism which actuates the connector spring contacts (which in some cases means it applies vertical force to compress the Z-actuated electrical spring contacts against the mating pads on a circuit element) can be comprised of a spring loaded top or lid. The lid may have one or more spring elements which provide high vertical pre-load, such that when the lid is closed, these lid springs are partially compressed and provide sufficient downward force on the interposer to fully compress the interposer contacts against the mating pads on the circuit structure to form a low resistance electrical connection. This pre-load can be tuned by adjusting the lid spring material and design to provide the correct force for a specific interposer design. The correct force for a given connector design can depend on the force required to compress each spring contact, and the number of spring positions on the connector. The pre-load springs in the lid also accommodate normal variations in the thickness of the interposer and the other elements between the lid spring and the circuit element that is being mated to. For example, in a 'minimum material' condition for thickness of the interposer, flex circuit, adhesive and stiffener, the springs in the clamp lid would be designed to provide sufficient force to fully compress all contact springs on the connector, plus some design margin to accommodate process and material variations. These elements in the thickness tolerance stack-up may include the flexible printed circuit, the stiffener, the adhesive that attaches the stiffener to the FPC, and other components in the stack up. Because the compression force is applied by a structure that is distinct and separate from the interposer, it can be designed to optimally perform this function without concern for providing other attributes or functions (such as providing structural support for the contacts, holding the contacts in correct alignment, aligning the connector to mating surfaces, etc.). It can be designed to provide the optimal force plus necessary design margin, as well as to provide sufficient lid spring working range to overcome any height stack up tolerances in, for example, the connector, the flex circuit, the stiffener and adhesive, etc. As a result, this structure can more readily accommodate stack up tolerances than can be achieved with existing clamping mechanisms for connectors, such as used in ZIF or mezzanine connectors.

Further, the compression force is provided by a different element of the structure than the retention, which in some embodiments of the invention is provided by tabs at one, two, or all 4 edges of the lid which clip under corresponding retention features (e.g., slots or latches) on the base of the clamping mechanism, or by other clipping or retention mechanisms. In some cases, the retention mechanism may snap into place in a way that can be sensed audibly and/or by tactile means by an assembler or automated, robotic assembler, and which can also be inspected to verify that full actuation has been achieved.

In order to provide effective clamping for the life of an electronic device, it may be necessary to utilize a creep resistant material to provide the clamping force and retention mechanism in the clamping structure. Such creep resistant materials are known, and can include high yield strength spring steels, copper alloys such as copper beryllium (including Alloy 25), phosphor bronze alloy, and other creep resistant materials.

In some embodiments, of the present invention, a lid to the clamping structure may be separate from the base. In other embodiments, it may be attached to the lid by a hinge mechanism. In yet other embodiments, there may not be a lid to the clamping structure. For example, the base structure may be constructed from spring material, and may have a shape that can provide downward spring force on the connector. Such a clamping structure may have retention features within these edges of the base.

In some embodiments, where corrosion resistance would be beneficial to the clamping structure, corrosion resistant alloys, or surface finishes like plated metals, can be used. For example, stainless steel, nickel, or phosphor bronze may be used. Alternatively, less corrosion-resistant materials, such as non-stainless spring steel or copper beryllium alloys may be plated with a more corrosion resistant material like nickel, or with a nickel barrier layer followed by a noble metal like palladium or gold. In some applications, such as high frequency applications, it may be desirable to minimize electromagnetic radiation that may emanate from an electrical connector assembly during function. Some embodiments of the present invention can provide effective electromagnetic interference (EMI) shielding. In particular, embodiments where there is a clamp base and a clamp lid, and where the clamp lid and clamp base are made of an electrically conductive material such as steel, copper alloy, or other conductive metals, and the lid and base cover and/or surround most or all of electrical connector with that conductive material, the emanation of stray electromagnetic radiation can be reduced from the interconnection can be reduced. This EMI shielding effect can be further enhanced when the clamp is electrically connected to a ground circuit in one or more of the mating circuit elements, such as through a solder connection to a grounded pad on a PCB. In other embodiments, a fully shielded cap, such as electrically conductive adhesive tape, could be inserted over any open areas in the clamp such as where the springs in the clamp lid emanate to apply pressure on the connector assembly.

A variety of alignment, compression, and retention mechanisms are described in the figures below, and others will be suggested to one of ordinary skill in the art.

The figures which accompany this patent specification illustrate several different embodiments of the above stated invention and contrast the present invention with the electrical connectors of the prior art. Of course, many other objects and advantages of the present invention will be apparent to one of ordinary skill in the relevant art in view of the following detailed description of the present invention, taken together with the accompanying drawings.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages and limitations of the prior art electrical connectors. In some embodiments it provides a simple, yet effective, clamping mechanism for releasably securing an electrical connector to one or more mating circuit elements. That is, it maintains the electrical connector in the desired location and orientation relative to the mating circuit element(s) while providing a normal force which maintains the electrical contacts securely compressed against the mating contact pads to provide an effective electrical connection between mating electrical contacts throughout the useful life of the electronic device.

The present invention provides a system in which the primary functions of the connector can be isolated and independently tailored and controlled, if desired. For example, many connectors use a spring force to retain the contacts in a compressed state to maintain the electrical connection, but the spring is often formed integrally with other components, preventing one from providing the ideal design forces for a spring - the designer merely takes the spring force provided for other means— e.g. to form a low resistance, separable electrical connection, and uses it the best he can for a secondary function, such as retaining the two halves of a two piece connector together using friction generated by the spring force, or by using other incidental attributes of an existing component of the connector. This results in compromised designs, as evidenced by system failures known to be induced by two-piece, friction- retained prior art connectors and clamping mechanisms that separate due to shock to the system. In order to minimize this type of failure, an engineer might increase the lateral spring force in prior art, two piece mezzanine connectors to increase the frictional forces and thereby increase the shock force required to force the connector open. However, such a design will make actuation and separation of the connector more difficult for assembly and rework, and will increase wear of the contact surfaces from assembly and disassembly. Notches or other retention features in the electrical spring contacts may also help improve retention during episodes of deceleration from shock to the system, but will increase complexity and cost of the spring contacts and may sacrifice electrical signal integrity due to resulting increase in the inductance of the spring contact. The present design allows for simplified assembly and disassembly of mating electrical connectors. One version of the clamp assembly is a single piece structure which is folded around a portion of the electrical connector to provide a clamping force. Another version uses a clamp which includes two separate pieces which are pivotably secured (by a hinge or other means) together at one end and latched at the other end. In this version, the base piece can be soldered or glued or otherwise secured to the first circuit element, and can provide attachment and alignment of the connector, as well as temporary retention to hold it in position until assembly can be completed. The hinged lid provides the spring compression force; and both the base and the lid have features which interact to provide retention. Another version includes two separate pieces, such as a base and a lid, that remain separate until they are snapped together during system assembly. As with the prior example, the base piece may be soldered or glued or otherwise secured to one circuit element, and can provide alignment and temporary retention of the connector. The lid piece may be freestanding, or may be attached to or intregated into the stiffener on an FPC. The lid may provide actuation and compression force, through built-in and robust, high spring constant, downward- oriented 'leaf springs or by other means, and will interface with the base to 'clip' into place to provide positive retention.

Of course, many modifications to the system and methods previously disclosed will be apparent to one of ordinary skill in the art. That person would also recognize that some of the features disclosed in connection with the preferred embodiment can be used without the corresponding use of other features. Accordingly, the foregoing description of the preferred embodiment should be appreciated as simply a teaching of the principles of the present invention and not in limitation of the invention which is defined solely by the allowed claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a cutaway side view of a pair of mated electrical connectors of the prior art;

Fig. 1 A is an enlarged view of an improved clamping system for securing electrical connectors;

Fig. 2 is a perspective view of one form of a clamp assembly useful in the present invention;

Figs. 3 - 5 shows perspective views of components of the clamp assembly of Fig. 2, with Figs. 3 and 4 showing the base of the clamp and Fig. 5 showing the cover of the clamp assembly;

Fig. 6 is a perspective view of the clamping assembly or system of Figs 2-5 assembling around a spring contact interposer;

Fig. 7 is a perspective view of a clamp assembly of the type shown in Figs. 2 - 5 assembled to a board using surface mount technology (SMT);

Fig. 8 is a view of the clamp assembly of the type shown in Figs 2 - 5 with a cable mounted therein;

Figs. 9 - 19a and 19b show alternate embodiments of the present invention .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 is a cross-sectional partial side view of an electrical connector assembly 10 of the prior art, commonly known as a two piece mezzanine connector or a board to board connector, including a first electrical connector half 8 (male) and a second electrical connector half 9 (female). In figure 1, the two connector halves are separated by a dashed line for clarity. The first electrical connector 8 is shown mounted on a first circuit element 20, which can be a printed circuit board (PCB) or flexible printed circuit (FPC) with attached electrical contacts 24 and 28. Electrical contacts 22 and 26 extending from first electrical connector half 8 are attached to the electrical conductors 24 and 28, respectively, of circuit element 20, using solder or other electrical attachment means. The second electrical connector half 9 is shown mounted on a second circuit element 30, which can be a PCB or FPC with attached electrical conductors 34 and 38 Elastic electrical contacts 32 and 36 including formed spring portions, are attached at one end to the electrical conductors 34 and 38, respectively, of circuit element 30, using solder or other electrical attachment means. An insulating member 42 is positioned between the electrical contacts 32, 36 of connector half 9. Connector half 8 includes guides 43, 45 mounted to the first electrical connector half 8, and connector half 9 includes insert portions 44, 46 to precisely accommodate the guides 43, 45 to provide lead-in to help locate and position the electrical contacts 32, 36 in connector half 9 and electrical contacts 22, 26 in connector half 8 together in a proper mated relationship when the first electrical connector half 8 is mated with the second electrical connector half 9. Beveled feature on inside edge of insert portions 44, 46 also provides limit to depth of insertion of male connector half 8 into female connector half 9, by contacting a corresponding beveled feature on outside edge of insert portions 43, 45. Electrical contacts 22, 26 of connector half 8 are located against and contained within insert portions 43, 45, and together form a rigid surface against which the elastic electrical contacts 32, 36 of connector half 9 are compressed during mating of the connectors. The compression force is lateral, in that it is parallel to the surfaces of the mating circuit elements 20 and 30. The lateral spring force generates increased frictional force between elastic contacts 32, 36 and contacts 22, 26 respectively. Hence the electrical contacts in this electrical connector system are required to perform multiple functions, including providing separable, low resistance electrical connection, providing a wiping force to remove oxides or contaminants, providing retention of the two connector halves to each other by generating frictional forces, and providing alignment function during mating. As can be seen, all 4 electrical contacts, and in particular contacts 32, 36 of connector half 9, are lengthy, resulting in increased material usage for the elastic spring material and any noble metal plating on the contacts, as well as complicating the stamping and forming process required to fabricate the contacts. In addition, the long and convoluted electrical path for contacts 32, 36 increases electrical inductance and can therefore degrade signal integrity and reduce bandwidth of the connector system. In addition, insert sections 43, 45 of connector half 8 and 44, 46 of connector half 9 also serve multiple functions, including providing structural integrity to the connector, providing a biasing force against the force of the spring contacts, providing alignment of the two connector halves during assembly, providing insulation between electrical contacts, and maintaining the electrical contacts in proper position and alignment. The requirement to provide so many functions in the case of both the insert portions and the electrical contacts hence results in design compromises which result in a non- optimized connector design. These compromises contribute to problems including but not limited to larger connector footprint, thicker connector profile, degraded electrical performance, and non-positive friction-based retention which can inadvertently be released if the device is dropped or shocked.

Fig. 1A shows a cross-sectional, partial side view of an improved clamping system using the present invention for coupling a PCBeam electrical connector 30, which has been soldered onto a flexible printed circuit (FPC) 20 using BGA solder balls (23, 27), separably to a rigid PCB 40. As shown in this view, the PCBeam electrical connector 30 includes a plurality of solder ball contacts 21, 25 attached to the top surface (as oriented) of the PCBeam connector 30. Solder balls 23, 27 are fused to solder ball contacts 21, 25 on connector 30. The solder balls 23, 27 are attached to solder mating pads 29 on FPC 20. FPC 20 has a stiffener 50 on the side opposite the PCBeam connector 30. The electrical connector 30 includes a plurality of spaced, compliant electrical contacts 31, 35 which may be of the type sold by Neoconix, Inc. as its PCBEAM™ electrical contacts (which can be manufactured as taught in patents owned by Neoconix, Inc., such as US Patents 8,584,353; 7,758,351; and 7,645,147), A clamp cover 60 and a clamp base 70 are shown coupled to the electrical connector 30 and the mating PCB 40 and include spring members 62, 64 in contact with stiffener 50 to apply a force normal to the stiffener 50 and thereby normal to the electrical connector 30, in order to to urge the electrical connector 30 together with its PCBeam electrical contacts 31, 35 extending downward from the connector in the orientation shown, downward onto PCB 40 so that electrical contacts 31, 35 make low resistance electrical connection to electrical contact pads 41, 42 on PCB 40. Cover 60 maintains PCBeam connector 30 and PCB 40 in a mating and electrically-conductive relationship with the PCB contact pads 41, 42 respectively. A retention mechanism is represented by features 73 on upper edge of clamp base sides 71, 72. More detailed representations of retention mechanism options are shown in subsequent drawings.

Fig. 2 shows a perspective view of one version of a clamp assembly 50 which is useful in practicing the invention of this patent. The clamp assembly 50 includes the clamp base 70 and the clamp cover 60 (partially shown in Fig. 1A), and as illustrated and described in greater detail in connection with Figs. 3-5. The clamp base 70 includes a pair of latches 72 and a pair of mounting holes 74, with the clamp cover 60 including a pair of projections 67 which are each mounted within one of the mounting holes 74, respectively, creating a hinge assembly for the lid, and a pair of projections 69 which each may be releasably but positively secured under one of the latches 72. The reference numeral 52 points to a clearance or gap between the clamp base 70 and the clamp lid 60 which allows for a FPC to exit the clamp 50. The springs 62 are separated from the wall 66 of the cover 60 and formed downward to provide a spring force on a connector mounted within the clamp in the z direction. That force is transmitted through the connector to the electrical contacts on the underside of the connector, compressing them in the z direction against mating electrical contact pads on a circuit element on which the clamp is mounted (not shown). Holes 68 are formed on the edge of the clamp cover opposite the hinge, to allow for insertion of a clamp opening tool (not shown) to release the clamp cover 60 from the clamp base 70 if necessary for repair or rework of the assembly.

Fig. 3 is a perspective view of the top side of the clamp base 70 shown in Fig. 2 and Fig. 4 is a perspective view of the bottom of the clamp base 70 of Fig. 2. The clamp base 70 includes four side bars labeled with the reference numerals 71a, 71b, 71c and 7 Id which generally form a rectangle when assembled, with side bars 71a and 71c being generally parallel to each other and side bars 71b and 7 Id being generally parallel to each other and perpendicular to the side bars 71a and 71c. Side bars 71a and 7 Id generally act as spring elements, and contact points 73 are positioned on the sides 71a, 7 Id to provide forces on a board or other electrical component (not shown in this view) when mounted within the clamp of Fig. 2 (with only a clamp base 70 portion of the clamp assembly being shown in Figs. 3 and 4). The contact point 73 on the side bar 71a provides a force in the x direction in conjunction with the springiness of side bar 71a and the contact point 73 on the side bar 7 Id providing a force in the y direction in conjunction with the springiness of side bar 7 Id. The side bar 71c may be shorter in the Z- direction to allow vertical clearance for a FPC to exit the clamp between the clamp base 70 and the clamp lid 60. The clamp base 70 includes alignment stops 75 on the side bar 71b and the side bar 71c also provides an alignment stop. The stiffness of side bar 71c may be increased by including a longitudinal bend, not shown, approximately 90 degrees to the side bar 71c along its length, and in the plane of the PCB surface it would be mounted on, so that it acts as an effective alignment stop. Side bar 71b has significant stiffness due to its orientation in the plane of the mounting surface on the PCB, and due to the additional material in alignment stops 75 oriented approximately 90 degrees to the side bar 71b. As shown in Fig. 4 the bottom of the clamp base is generally planar (flat) for mounting to a surface mount board, if desired.

Fig. 5 is a perspective view of the clamp cover 60 of the clamp assembly of Fig. 2. The clamp cover 60 is shown with pins 67 at one end (serving as a rotating hinge when inserted into the apertures 74 on the clamp base 70) and latches 69 (which releasably secure the clamp cover 70 to the clamp base 60 by snapping under latches 72 in clamp base 60 when the cover is closed and actuated). Holes 68 are also shown for allowing the clamp opening tool (not shown) to open the clamp. The tool, when inserted vertically from above, can be pried back toward the center of the cover, resulting in latches 69 deforming outward from the clamp base 60 and releasing them from latches 72. It should be noted that the design of the clamp features in Fig. 5 and other figures enables high volume, low cost

manufacturing of these structures using, for example, stamping and forming processes via a progressive die system. Fig. 6 shows a perspective exploded view of an alternative, 2 piece clamp assembly with the connector 20 (an interposer) inserted therebetween. The clamp assembly in figure 6 is not hinged, and includes the clamp base 70 and a separate clamp lid 60. The clamp base 70 includes slots 77 at either end as well as alignment stops 71c and 75, with springs 73 (not shown in this figure) pushing a connector mounted therein toward one of the alignment stops 71c, 75. Projections (or ears) 62 are mounted on each end of the clamp lid 60 and become inserted within the slots 77 when the clamp lid 60 is latched into the clamp base 70. Each projection or ear 62 also includes a tab 62a, so that when the tab 62a is pressed down, the ends of the clamp cover 60 are spread out, releasing the lid from the slot 77. The clamp lid 60 also includes a medial spring 61 which provides vertical (z direction) force) to press electrical contacts (such as PCBEAM™ spring contacts) against complementary contacts (such as pads on a printed circuit board). The clamp base 60 may be formed of a metal such as stainless steel, spring steel, copper beryllium alloys, phosphor bronze, or other suitable materials and carries a lower surface of the clamp base 60 which is generally planar (flat) to mount to a printed circuit board (PCB) using surface mount technology, although other forms of attachment and location could be used to advantage, such as locating projections at the corners for positioning in the desired location and a screw for securing the clamp base to the electrical connector. The interposer or electrical connector 20 which is shown in this view is captivated between the clamp base 70 and the clamp lid or cover 60 when the clamp cover 60 is secured to the clamp base 70 (and when the clamp cover 60 is released, the clamp cover is free to move away from the clamp base to allow for the connector 20 to be inserted and/or removed and/or replaced. The interposer or electrical connector would in this configuration typically be attached, as through surface mount processing utilizing solder, to an FPC (not shown for clarity), which would be oriented above it in this view. In this configuration, the FPC would be on top of the interposer, and the elastic PCBeam electrical contacts on the bottom of the interposer, facing the PCB on which the clamp base would be mounted.

Fig. 7 shows a perspective view of another clamp assembly of the present invention mounted to a surface of a printed circuit board (PCB) or similar planar surface. The clamp base 70 has a planar (flat) lower surface for easy attachment to the printed circuit board (PCB) 20 shown in this view, which can be mounted using conventional attachment techniques such as surface mount technology or adhesive materials. The PCB 20 is shown with a plurality of electrical contacts which may be in a land grid array configuration, or other conventional or custom configuration of electrical contact pads. The clamp cover 60 is mounted to the clam base 70 using a hinge 67 which allows the assembly to be shipped as a single piece and attached to the electrical connector as a single piece, if desired. The clamp cover 60 includes a flat middle piece 61 which allows for a vacuum nozzle from an automated, high speed pick and place machine to be used to place the clamp assembly in the desired position and orientation on the PCB prior to soldering. The cover 60 includes two pairs of integral or built in compression 'leaf springs 62 as well as a pair of projections 69 used for latching the cover 60 to the base 70 by snapping under the latches 72. The latches 72 secures the connector (not shown in this view ) in place when the cover 60 is in its closed position with the projections 69 hooked under the latches 72 and provides an audible click to indicate that the cover is latched in place. The base latches 72 have a beveled chamfered leading edge on top to facilitate the sliding of cover projections 69 forward and under the flat lower edge of latches 72 for positive retention. The leaf springs 62 provide a compression force on the connector and the mating electrical contacts (not shown) when the cover 60 is closed. The latching mechanism of the projections 69 and the latches 72 hold the cover 60 closed but the cover 60 can be reopened for rework if needed.

Fig. 8 shows a perspective view of a slightly modified clamp assembly of the present invention. The clamp cover 60 is positioned to locate and secure the electrical connector attached to the end of FPC 30 in the desired orientation and location. The clamp base 70 has a projecting member 77a which biases the connector against the opposing edge of the base, which serves to position and locate the connector with respect to the PCB. The release mechanism shown in this embodiment is slightly different from mechanisms shown in other views. Outward projecting lip 62a of clamp lid 60 includes a single hole 62b which can accommodate a tool to facilitate release of the connector lid for repair or rework of the assembly.

Figs. 9 - 19a and 19b show alternate embodiments to the clamping system described above. Fig. 9 shows a side view of a different clamp system using a hinged clamp lid or cover 60' and a clamp base 70'. Lid 60 has two downward facing springs which provide normal force to compress a connector-FPC assembly to mate it electrically to a PCB. Fig. 10 shows a flexible cable 100 with a plurality of electrical contacts 102 on a PCBeam interposer which has been attached and electrically interconnected to a flexible printed circuit (FPC). A stiffener is located under the connector on the opposite side of the flexible cable (FPC). It would commonly be desired to secure the PCBeam connector / flex circuit assembly in electrical connection with a set of mating contacts on a separate member (not shown), using a clamping mechanism, such as the one shown in figure 9. In this case, the FPC would be flipped over so the PCBeam contact springs were facing down toward LGA pads on the mating circuit element, such as a PCB. The PCB LGA pads would be located inside the 4 edges of the clamping mechanism, such as shown in figure 9, in an open area in the clamp base. Fig. 11 shows a top view of such a FPC as shown in Fig. 10, 100, flipped over and secured in place by a clamp lid 60 to mate it to the underlying PCB. Fig. 12 shows an assembly view of an alternative structure for clamping an FPC connector assembly to a mating circuit element, including the components to secure the FPC cable and connector 106 in place on a PCB, using a screw 104, a stiffener 105, a connector 106, a printed circuit board (PCB) 107 and a post nut 108. The stiffener 105, shown with the FPC emanating from the lower left edge, has two tooling pins shown at opposite corners which are attached to the PCB 107 in the desired location by press fit or soldering or by other means. The pins and the internally threaded post in the center combine to provide alignment between the stiffener 105 and the cable 100 assembly to the connector and PCB. The stiffener 105 mounted to the cable 100 uniformly distributes clamping force on the flex-connection PCB assembly when the screw 104 is tightened. The connector 106 has a plurality of electrical contacts of the LGA/LGA PCBeam type with surface emanating spring contacts on both surfaces to mate to flex circuits on the top side and PCB contact pads on the bottom side. The internally threaded post nut 108 has a flat head with the outside diameter of the post fitting snugly in a hole in the PCB 107, connector 106, stiffener 105 to provide alignment amongst them. The screw 104 is secured within the post nut 108. Fig. 13 shows, from left to right, a top view, a cut-away side view and a perspective view of the post nut 108 of Fig. 12. The underside of the post nut may be plated with solderable metal to allow soldering of the post nut 108 to a pad surrounding the PCB hole, on the underside of the PCB 107, if desired. Fig. 14 - 16 show an alternative spring compression and retention clip system (2 shown in Fig. 14) used to secure a connector in electrical contact with a PCB. The retention clips 110 (spring members) are attached to the PCB in tight registration to LGA pads on the PCB using solder or other suitable attachment process. The retention clip 110 interacts with an integral retention system 116 on edge of the connector 115, which retention system 116 can be molded or machined or otherwise formed, to maintain a normal force on the connector assembly to compress the PCBeam electrical contacts in order to maintain them in low resistance electrical connection to LGA pads on the PCB. In Fig. 14, connector 115 is interconnected to FPC 111, having optional stiff ener 112, and serves to electrically interconnect FPC 111 to PCB 113. Fig. 15 is a close up of the retention clip 110 in which inter-digitated fingers 120 on the clip 110 fit within corresponding slots on the connector retention system 116, and fingers 122 on the connector retention system 116 fit within corresponding slots on the clip 110, in order to align them relative to one another during insertion and provide downward force on the connector-FPC assembly. Fig. 16 shows a side view of the clamping mechanism of Figs. 14 - 15, where the clip is made of sheet metal, and which is preferably made of a sheet metal with good spring properties, such as certain steel alloys, copper-beryllium alloys, phosphor bronze, or other spring metals. In some cases there may be a metal tab on clip 130 to assist in release of the interposer to allow rework. In this figure the clip is shown mounted to a PCB and the PCB will typically carry electrical contacts (not shown) to mate with contact springs on the interposer (connector) 132 coupling to a flex circuit with a stiffener on top of the flex circuit.

Figs. 17 - 19 show yet other alternate embodiments of the clamp assembly of the present invention, where the clamp is comprised only of a single piece base, with no lid. The base includes sheet metal with a lower surface secured to the PCB surface with two or more vertically protruding spring clips designed to interact with certain retention feature designed into the connector. This type of clamp design relies on tight control of thickness tolerances of an electrical connector/cable (FPC)/stiffener assembly (not shown) in order to apply sufficient force to adequately compress spring contacts on the electrical connector against mating LGA pads on the PCB. Fig. 17 shows a simple structure of this type with two vertically protruding sides with clip openings. The clip openings would interact with protruding tabs on the connector, which would temporarily spread the vertical sides during insertion and snap into the openings, thus retaining the connector. The protruding tabs on the connector could be molded to provide tight vertical thickness tolerance, or they could be an integral part of the connector body, which in the case of the PCBeam connector could be a printed circuit-like structure. The vertical sides shown in Fig. 17 have relatively little Z-axis compliance. Fig. 18 shows an alternative clamp design to that shown in Fig. 17, which requires no special retention feature on the connector. In the clamp 140 shown in Fig. 18, clamp 140 is mounted onto PCB 143, by bonding it to bonding pad 144 using solder, adhesive, or other bonding means. Clamp 140 has 4 vertical sides which interact with the 4 edges of the connector 145 to properly align it to the PCB. Two opposite vertical sides have lead-in tabs canted outward, and retention features 146 which snap over the top of the connector edges to hold it in compression against the PCB. Spring contacts on the underside of connector 145 connect to PCB contact pads 142 to form low resistance electrical interconnections. Fig. 19 is an alternate embodiment to that shown in Fig. 18, in which a connector assembly has spring loaded alignment and retention features on all four sides to assist with the connector registration and to compress and retain the connector on the PCB once the connector is fully inserted and snapped in, such that the surface of the connector reside under the retention features (two per side) on the four sides of the clamp structure. Fig. 19B shows one side has a cut out 150 along the bottom edge of one or more side, to allow for a pass through of circuit traces on the PCB without shorting to the clamp. The generally 'LP shaped clamp sides prevent the sides from being too stiff, which could make insertion and removal of the connector during assembly difficult, while also allowing room for pass through of a flexible printed circuit, if one is attached to the connector. The electrical connector (not shown in this Fig.) could be attached to an FPC and the connector would in that case electrically interconnect circuits on the FPC to circuits on the PCB.

The preferred embodiments of the present invention have been disclosed with some particularity in the foregoing description of the invention. Of course, many modifications and adaptations can be made without departing from the spirit of the present invention, which is defined solely by the claims which follow and those equivalents which one of ordinary skill in the relevant art would be inclined to substitute. For example, the shape of the clamp assembly has been described with some particularity in its preferred embodiment, but it could have a different shape, different number of components or even a different material, depending on the application. The type of electrical connector and electrical contacts could also be change, if desired, so that the contacts might be mating electrical contacts of the type sold by Neoconix as its PCBEAM™ contacts or other suitable contacts including pogo pins. Compression, alignment and retention for other types of connectors can be achieved with other embodiments of this invention, including 2 piece mezzanine connectors, ZIF connectors, and sockets. Other forms of latches and latch releases may be used to advantage - or in some instances a latch release might not be necessary. Functions can be achieved with a spring actuated clamping mechanism as shown, or with a screw down clamping mechanism (possible with a stiffener). In the latter case, separate SMT or press fit alignment pins (or projections) mounted on the mating circuit element provide alignment of the connector to the circuit element. The FPC may be attached to the connector with solder or ACF, or can be separably attached with compliant contact springs as is done on the PCB side. Further, the hinge mechanism can be altered, if desired, or some applications may use a single piece with an integrated hinge, and other applications may use a separate lid with no hinge, as shown in figure 6. The clamp may be metal in some instances or a non-conductive material such as plastic may be used in some applications - and, if metal is used, an insulating layer may be provided to keep from transmitting electrical current. In some cases, the metal clamp assembly may be connected to ground circuits, and may provide substantial EMI shielding to the assembly. Some features of the present invention can be used to advantage without the corresponding use of other features. Thus, it will be appreciated that the foregoing discussion of the present invention is for the sake of illustrating the principles of the present invention and not in limitation of the invention, which is defined solely by the claims which follow.

Claims

CLAIMS Having thus described the invention, what is claimed is:

1. An electrical connector assembly comprising:

a first electrical connector having a plurality of electrical contacts;

a second member having a plurality of electrical contacts;

a securing assembly for maintaining the electrical contacts of the first electrical connector in electrical connection with the contacts of the second member, said securing assembly including a base portion secured to the second member on its edges but substantially open in its center region, a separate cover portion with integrated springs elements projecting downward from the plane of the cover, and attachment structures on at least two opposing edges of each of the base and cover to allow the cover to snap onto the base to provide a downward force onto an electrical connector mounted between the cover and the base of the securing assembly

2. An electrical connector assembly comprising:

a first electrical connector having a plurality of electrical contacts on at least one surface;

a flexible circuit member on the underside of which the first electrical connector is mounted and electrically coupled;

a second circuit member having a plurality of electrical contacts;

a securing assembly for maintaining the electrical contacts of the first electrical connector in electrical connection with the contacts of the second circuit member, said securing assembly including a base portion secured to the second member on its edges but substantially open in its center region, a separate cover portion with integrated springs elements projecting downward from the plane of the cover, and attachment structures on at least two opposing edges of each of the base and cover to allow the cover to snap onto the base to provide a downward force onto an electrical connector mounted between the cover and the base of the securing assembly; and a clearance area on one edge of the base to allow the flexible printed circuit to emanate from the securing assembly.

3. An electrical connector assembly comprising:

a first electrical connector having a plurality of electrical contacts;

a flexible circuit member on the underside of which the first electrical connector is mounted and electrically coupled; a second member having a plurality of electrical contacts;

a securing assembly for maintaining the electrical contacts of the first electrical connector in electrical connection with the contacts of the second member, said securing assembly including a base portion secured to the second member, a cover portion coupled to the base portion, a hinge connecting the base portion and the cover portion at one side of the securing assembly and a latch carried on the base portion at an opposite side of the assembly from the hinge for releasably coupling with a portion of the cover; and a clearance area on one edge of the base to allow the flexible printed circuit to emanate from the securing assembly

4. An electrical connector assembly comprising: a first electrical connector having a plurality of electrical contacts;

a second member having a plurality of electrical contacts; a securing assembly for maintaining the electrical contacts of the first electrical connector in electrical connection with the electrical contacts of the second member, said securing assembly including a base portion secured to the second member, a cover portion coupled to the base portion, a hinge connecting the base portion and the cover portion at one side of the securing assembly and a latch carried on the base portion at an opposite side of the assembly from the hinge for releasably coupling with a portion of the cover.

5. An electrical connector assembly of the type described in Claim 4 wherein the securing assembly is provided with a flat lowermost surface with the flat lowermost surface secured to the second member using surface mount technology.

6. An electrical connector assembly of the type described in Claim 4 wherein the latching mechanism includes a plurality of hooks on one member and a projection which fits under the hooks on the other member.

7. An electrical connector assembly of the type described in Claim 4 wherein the latching assembly includes a release mechanism which allows the latched members to be separated when desired.

8. An electrical connector assembly of the type described in Claim 7 wherein the release mechanism is a tab on the end of the cover furthest from the hinge and extending away from the hinge.

9. An electrical connector assembly of the type described in Claim 4 wherein the base portion of the clamp includes four bars each mounted at right angles to the adjacent bar to form a rectangular periphery with an open center region.

10. An electrical connector assembly of the type described in Claim 4 wherein the base portion includes a rigid stop member on at least two adjacent sides for locating an electrical connector mounted therein.

11. An electrical connector assembly of the type described in Claim 10 wherein the base portion includes a first spring member on one side and a second spring member on another adjacent side which function to bias the connector laterally against the rigid stop members for accurate alignment.

12. An electrical connector assembly of the type described in claim 11 wherein at least two of the four clamp base sides has an outward canted upper edge to assist in insertion of a connector.

13. An electrical connector of the type described in Claim 4 wherein the clamp base is located with respect to one electrical connector using at least one locating projection mounted on the second member.

14. An electrical connector of the type described in Claim 4 wherein the clamp lid is secured to one electrical connector using at least one screw.

15. An electrical connector assembly comprising:

a first electrical connector having a plurality of electrical contacts;

a second member having a plurality of electrical contacts;

a securing assembly for maintaining the electrical contacts of the first electrical connector in electrical connection with the electrical contacts of the second member, said securing assembly including a base portion secured to the second member, a cover portion coupled to the base portion, a hinge connecting the base portion and the cover portion at one side of the securing assembly, a latch carried on the base portion at an opposite side of the assembly from the hinge for releasably coupling with a portion of the cover, and downward facing springs in the cover which forcibly urge the first electrical connector into intimate electrical contact with the second member when the cover is in closed position.

16. A method of assembling an electrical connector assembly including a first member with a plurality of electrical contacts being mated to electrical contacts on a second member wherein the steps of the method comprise: mounting a clamp base to one member containing electrical contacts in precise position relative to the position of the electrical contacts; securing the other member having electrical contacts in mated relationship with the electrical contacts on the one member using alignment features on the clamp base to position it, said securing including the step of mounting a clamp cover to the clamp base and latching the clamp cover to the clamp base so that the second member is held in place and compressed by the clamp cover.

17. A method of assembling an electrical connector assembly including the steps of Claim 15 and further including the step of providing the clamp cover with a release mechanism to allow for the clamp cover to be uncoupled from the clamp base to allow access to the second member.

18. A method of assembling an electrical connector assembly including the steps of Claim 15 wherein the clamp base includes a plurality of connected bars around a central open area and at least one of the bars includes a spring member to urge the electrical connector into a desired orientation and position with respect to another more rigid locating member.

19. A method of assembling an electrical connector assembly including the steps of Claim 15 wherein the clamp base includes a stop to prevent the member with electrical contacts from moving beyond the stop and an opposing spring for urging the member into the stop.

20. A method of assembling an electrical connector assembly including the steps of Claim 15 wherein the method includes the step of securing the clamp base to the member using surface mount technology.

21. A method of assembling an electrical connector assembly including the steps of Claim 15 wherein the method further includes the step of providing at least one locating projection on the connector and mounting the clamp base to the member in a position defined by the locating projection.

22. A method of assembling an electrical connector assembly including the steps of Claim 15 wherein the method further includes the step of securing a clamp lid to the member using at least one screw.