US 5,938,451 AGrant
Electrical Connector With Multiple Modes of Compliance
Issue Date:1999-08-17
•38 Claims
•10 Drawing Sheets
Abstract
A solderless connector with multiple modes of compliance providing an initial insertion force differing from the secondary insertion force. The connector has multiple compliant members that can be independently adjusted to accommodate a wide range of circuit members. The connector allows the contact members to be arranged with a fine pitch without shorting. The multiple compliant members accommodate a wide range of thermal and vibrational effects, and can be configured to accommodate a wide range of compression distances. An electrically insulative connector housing is positioned substantially between the first and second circuit members. A resilient contact member is positioned generally within the connector housing. The contact member has resilient first and second circuit interface portions. The resilient contact member comprises a first compliant member. At least one end stop is provided for engaging with the contact member in a second mode of compliance. A resilient, dielectric encapsulating material surrounds a portion of the resilient contact member. The encapsulating material comprises a second compliant member, such that the first and second compliant members are capable of providing a first mode of compliance. In an alternate embodiment, resilient material may be located adjacent to a rigid contact member.
Metadata
Assignee
- Gryphics, Inc.
Inventor
- James J. Rathburn
Application Information
Application Number:US 8521166
Filing Date:1997-05-06
Priority Date:1997-05-06
Art Unit:289
Classifications
IPC:
H01R 909
Field of Search:
43966;71;591;592
Patent Drawings (10 sheets)
Description
Field of the Invention
The present invention is directed to a solderless connector with multiple modes of compliance providing an initial insertion force differing from the secondary insertion force, and more particularly, to a connector having multiple compliant members that can be independently adjusted.
Background of the Invention
The current trend in connector design for those connectors utilized in the computer field is to provide both high density and high reliability connectors between various circuit devices. High reliability for such connections is essential due to potential system failure caused by misconnections of devices. Further, to assure effective repair, upgrade, testing and/or replacement of various components, such as connectors, cards, chips, boards, and modules, it is highly desirable that such connections be separable and reconnectable in the final product.
Pin-type connectors soldered into plated through holes or vias are among the most commonly used in the industry today. Pins on the connector body are inserted through plated holes or vias on a printed circuit board and soldered in place using conventional means. Another connector or a packaged semiconductor device is then inserted and retained by the connector body by mechanical interference or friction. The tin lead alloy solder and associated chemicals used throughout the process of soldering these connectors to the printed circuit board have come under increased scrutiny due to their environmental impact. The plastic housings of these connectors undergo a significant amount of thermal activity during the soldering process, which stresses the component and threatens reliability.
The soldered contacts on the connector body are typically the means of supporting the device being interfaced by the connector and are subject to fatigue, stress deformation, solder bridging, and co-planarity errors, potentially causing premature failure or loss of continuity. In particular, as the mating connector or semiconductor device is inserted and removed from the present connector, the elastic limit on the contacts soldered to the circuit board may be exceeded causing a loss of continuity. These connectors are typically not reliable for more than a few insertions and removals of devices. These devices also have a relatively long electrical length that can degrade system performance, especially for high frequency or low power components. The pitch or separation between adjacent device leads that can be produced using these connectors is also limited due to the risk of shorting.
Another electrical interconnection method is known as wire bonding, which involves the mechanical or thermal compression of a soft metal wire, such as gold, from one circuit to another. Such bonding, however, does not lend itself readily to high density connections because of possible wire breakage and accompanying mechanical difficulties in wire handling.
An alternate electrical interconnection technique involves placement of solder balls or the like between respective circuit elements. The solder is reflowed to form the electrical interconnection. While this technique has proven successful in providing high density interconnections for various structures, this technique does not allow facile separation and subsequent reconnection of the circuit members.
An elastomer having a plurality of conductive paths has also been used as an interconnection device. The conductive elements embedded in the elastomeric sheet provide an electrical connection between two opposing terminals brought into contact with the elastomeric sheet. The elastomeric material that supports the conductive elements compresses during usage to allow some movement of the conductive elements. Such elastomeric connectors require a relatively high force per contact to achieve adequate electrical connection, exacerbating non-planarity between mating surfaces. Location of the conductive elements is generally not controllable. Elastomeric connectors may also exhibit a relatively high electrical resistance through the interconnection between the associated circuit elements. The interconnection with the circuit elements can be sensitive to dust, debris, oxidation, temperature fluctuations, vibration, and other environmental elements that may adversely affect the connection.
It is believed that a high density, repeatable, solderless, electrical connector that is tolerant to dust, debris, thermal and vibrational effect, and relatively easy to manufacture would constitute a significant advance in the art.
Brief Summary of the Invention
The present invention is directed to a solderless connector with multiple modes of compliance providing an initial insertion force differing from the secondary insertion force. The connector has multiple compliant members that can be independently adjusted to accommodate a wide range of circuit members. The present connector allows the contact members to be arranged with a fine pitch without shorting. The multiple compliant members accommodate a wide range of thermal and vibrational effects, and can be configured to accommodate a wide range of compression distances.
The connectors of the present invention may be used for electrically connecting first and second circuit members. Each circuit member has first and second operative surfaces with connector members, respectively.
In a first embodiment, an electrically insulative connector housing is positioned substantially between the first and second circuit members. A resilient contact member is positioned generally within the connector housing. The contact member has resilient first and second circuit interface portions. The resilient contact member comprises a first compliant member. At least one end stop is provided for engaging with the contact member in a second mode of compliance. A resilient, dielectric encapsulating material surrounds a portion of the resilient contact member. The encapsulating material comprises a second compliant member, such that the first and second compliant members are capable of providing a first mode of compliance.
Elastic deformation of the resilient encapsulating material and the contact member comprises the first mode of compliance. Deformation of the contact member during the first mode of compliance is typically minimal. Elastic deformation of the contact member in response to engagement with an end stop comprises the second mode of compliance.
At least one support member may be provided for supporting the contact member. In one embodiment, the support member comprises a pivot point around which the contact member rotates. The support member may also comprises a flexible filament capable of permitting translational and/or rotational movement of the contact member.
A template having a plurality of slots may be provided for maintaining a preferred spacing between the contact members. The housing preferably has an opening extending between first and second surfaces for receiving the resilient contact. The first and second circuit interface portions of the resilient contact member extend above or below a first surface of the housing.
The second mode of compliance at the first circuit interface portion may be less than, greater than, or equal to the second mode of compliance at the second circuit interface portion. The first and second modes of compliance are preferably within the elastic limits of the contact member.
The connector provides an initial insertion force and a secondary insertion force with the circuit member. The initial insertion force may be less than, greater than, or equal to the secondary insertion force. First and second end stops may be provided on the housing for engaging with the contact member to initiate the second mode of compliance. The first and second circuit interface portions preferably provide a wiping engagement with an opposing connector member.
The resilient contact member may be of a variety of shapes, such as curvilinear, flat, concave, convex, pointed, or a shape complementary to a shape of the connector member. The resilient contact member may be a wire or a piece of a conductive sheet material.
The connector may be configured to maintain the first operative surface parallel, perpendicular, or at a fixed angle relative to the second operative surface. The circuit members may be selected from the group consisting of a card edge, a j-lead device, a land grid array, a pin grid array, a flex circuit, a ribbon connector, a cable, and a ball grid array.
The resilient contact members are preferably an array of resilient contact members positioned generally within the connector housing. The housing preferably includes an alignment mechanism for aligning the first and second circuit interface portions with the connector members on the first and second circuit members.
In a second embodiment, a rigid contact member is positioned generally within the connector housing. The rigid contact member has first and second circuit interface portions. A resilient, dielectric encapsulating material comprising a first compliant member surrounds a portion of the contact member. The encapsulating material is capable of providing a first mode of compliance. A first resilient material comprising a second compliant member is interposed between the rigid connector member and an end stop on the housing, whereby the first and second compliant members are capable of providing a second mode of compliance.
The present invention also includes an assembly of the first and second circuit members operatively connected by the present connector.
Brief Description of the Several Views of the Drawings
FIG. 1 is a perspective view of an exemplary embodiment of the present connector.
FIG. 2A is a side sectional view of the connector of FIG. 1.
FIGS. 2B and 2C are perspective views of alternate contact members for use in the connector of FIG. 2A.
FIG. 3 is a side sectional view of an assembly of circuit members incorporating the connector of FIG. 1.
FIG. 4A is a side sectional view of a connector for engagement with a solder ball device.
FIG. 4B is a perspective view of the contact member of FIG. 4A.
FIG. 5A is a side sectional view of an alternate connector for engagement with a solder ball device.
FIG. 5B is a perspective view of the contact member of FIG. 5A.
FIG. 6A is a side sectional view of a connector for engagement with a j-lead device.
FIG. 6B is a perspective view of the contact member of FIG. 6A.
FIG. 7A is a side sectional view of a connector for engagement with an edge card connector.
FIG. 7B is a perspective view of the contact member of FIG. 7A.
FIG. 8A is a side sectional view of a connector for engagement with a circuit board.
FIG. 8B is a perspective view of the contact member of FIG. 8A.
FIG. 9A is a side sectional view of an alternate connector for engagement with a circuit board.
FIG. 9B is a perspective view of the contact member of FIG. 9A.
FIG. 10A is a side sectional view of an alternate connector for engagement with a circuit board.
FIG. 10B is a perspective view of the contact member of FIG. 10A.
FIG. 11A is a side sectional view of a connector for engagement with a pin lead device.
FIG. 11B is a perspective view of the contact member of FIG. 11A.
FIG. 12A is a side sectional view of an alternate connector according to the present invention.
FIG. 12B is a perspective view of the contact member of FIG. 12A.
FIG. 12C is a side sectional view of an alternate connector of FIG. 12A.
FIG. 13 is a perspective view of the connector of FIG. 12A.
FIG. 14A is a side sectional view of a connector according to the present invention for use with an edge card device.
FIG. 14B is a perspective view of the contact member of FIG. 14A.
FIG. 15 is a side sectional view of a connector according to the present invention for use with a j-lead device.
FIG. 16A is a side sectional view of a connector according to the present invention for use with a solder ball device.
FIG. 16B is a side sectional view of an alternate connector according to the present invention for use with a solder ball device.
FIG. 17 is a side sectional view of a connector according to the present invention for use with a pin lead device.
FIG. 18 is a perspective view of an alternate connector according to the present invention.
FIG. 19 is a sectional view of the connector of FIG. 18 prior to engagement with a circuit member.
FIG. 20 is a sectional view of the connector of FIG. 18 after engagement with a circuit member.
Detailed Description of the Invention
FIG. 1 is a perspective view of an exemplary embodiment of the present solderless connector 40. A plurality of resilient contact members 42 are retained in a housing 44 by an encapsulating material 46. The housing 44 preferably includes an alignment mechanism, such as openings 82. The density and spacing of the resilient contact members 42 may be altered to accommodate various circuit members.
FIG. 2A is a side sectional view of the solderless connector 40 positioned to engage with a first circuit member 50 and a second circuit member 52. The first circuit member 50 has a first operative surface 54 containing a solder ball device 56. The second circuit member 52 has a second operative surface 58 containing a connector pad 60. The circuit members 50, 52 may be printed circuit boards, circuit modules, integrated circuit devices, cable, flex circuit, ribbon connector, semiconductor devices, including surface mounted devices, and a variety of other electrical components.
The resilient contact member 42 is retained in the housing 44 by a resilient, dielectric encapsulating material 46. FIGS. 2B and 2C provide a perspective views of contact members 42B, 42C, respectively, having prongs 88 to assist in locating the contact members prior to encapsulation. The contact member 42 may optionally be retained in the housing 44 by mechanical means, such as suspension filaments 43 illustrated in FIG. 2A. The filaments 43 are preferably anchored to the housing 44. The filaments 43 may be permanent or may be removed after application of the encapsulating material 46. The suspension filaments 43 may be a rigid material or a flexible material. They are preferably flexible, but not extendible, so as to permit limited translational and rotational movement of the contact member 42. Translational movement refers to movement having horizontal and/or vertical components.
The contact member 42 has a first circuit interface portion 62 that may extend above a first surface 64 of the housing 44. A second circuit interface portion 66 of the contact member 42 extends above the second surface 68 of the housing 44. Either of the circuit interface portions 62, 66 may be recessed below the surfaces 64, 68 of the housing 44. Distal end 70 of the contact member 42 is positioned opposite end stop 72 on the housing 44. Center portion 75 of contact member 42 is positioned opposite end stop 78 on the housing 44. Distal end 74 of the contact member 42 is located opposite end stop 76 on the housing 44.
Alignment of the two circuit members 50, 52 relative to the connector 40 may be provided by utilizing a protruding pin 80 which extends from a cover 81 extending over the circuit member 50. The pin 80 is aligned and positioned with corresponding opening 82 in the housing 44. A receiving opening 84 is provided in the circuit member 52 for completing the alignment process. It is understood that other means of alignment are readily possible, including the provision of pins extending from opposing surfaces (upper and lower) of the housing 44 for insertion within corresponding openings within the respective circuit members 50, 52. In actual application, two or more alignment mechanisms, such as the protruding pin 80, would typically be provided to achieve proper alignment of the components 50, 52, 40. Other mechanisms for retaining the circuit members 50, 52 in a functional engagement with the connector 40 are disclosed in U.S. Pat. Nos. 4,445,735 (Bonnefoy); 4,593,961 (Cosmo); 4,793,814 (Zifcat et al.); 5,061,192 (Chapin et al.); and 5,096,426 (Simpson et al.).
The housing is preferably constructed of a dielectric material, such as plastic. Suitable plastics include phenolics, polyesters, and Ryton.RTM. available from Phillips Petroleum Company. The contact member is preferably constructed of copper or similar metallic materials such as phosphor bronze or beryllium-copper. The contact members are preferably plated with a corrosion resistant metallic material such as nickel, gold, silver, or palladium. Examples of suitable encapsulating materials include Sylgard.RTM. available from Dow Corning Silicone of Midland, Mich. and Master Sil 713 available from Master Bond Silicone of Hackensack, N.J.
FIG. 3 is a side sectional view of the connector 40 incorporated into an assembly comprising circuit members 50, 52. As the connector 40 is pressed onto the circuit interface portion 66, it comes in contact with the pad 60. The compliant encapsulant 46 allows for initial movement of the distal end 74 until it contacts end stop 76 on the housing 44. The movement of the distal end 74 preferably includes both vertical and horizontal components so as to cause a wiping action of the circuit interface portion 66 across the surface of the pad 60.
Elastic deformation of the contact member 42 and movement of the contact member 42 within the relatively soft encapsulating material 46 defines a first mode of compliance. The filaments 43 may also contribute to the first mode of compliance where present. The first mode of compliance compensates for non-planarity of the contact members on the circuit member 52. A relatively soft encapsulating material 46 provides a relatively low initial insertion force for the present connector 40. Insertion force refers to engagement of the present connector 40 with one or more circuit members 50, 52.
After the distal end 74 of the contact member 42 is engaged with the end stop 76, the base metal of the contact acts as a load spring, providing the second mode of compliance. The end stop 76 prevents compression beyond the elastic limit of the contact 42 or the encapsulant 46. Similarly, the distal end 70 of the contact 42 then encounters end stop 72 on the housing 44, stopping rotational and translational movement in either the horizontal or vertical directions.
The first mode of compliance is determined primarily by the resilience of the encapsulating material 46, although the elastic deformation of the contact member 42 and the filaments 43 may also be factors. The encapsulant 46 provides a relatively large range of motion at a low force, allowing for the contact 56 to achieve continuity and planarity despite a significant mismatch. The filaments 43 can help define the rotational or translational movement of the contact member 42 during the first mode of compliance.
Once the contact member 42 is compressed against the end stops72, 78, the base metal substantially defines the second mode of compliance, providing long term connection that resists failure due to fatigue, vibration, temperature fluctuation, and excessive or repeated insertion. The second circuit interface portion 66 operates similarly, although the initial and secondary insertion forces may vary.
The significance of the present connector 40 is that interconnection between the contact member 42 and the device leads 56, 60 is independently acting and independently controlled. For example, the connector 40 is capable of having a different first mode of compliance for the first and second circuit interface portions 62, 66, respectively, by using two or more encapsulating materials. The geometry or thickness of the contact member may also be adjusted to provide a different second modes of compliance at the first and second circuit interface portions 62, 66. For example, the first circuit interface portion 62 provides greater resistance to the contact 56 in the second mode of compliance. The geometry of the second circuit interface portion 66 is such that the resistance provided to the contact 60 in the second mode of compliance is less than the resistance provided by the first circuit interface portion.
The present methodology permits the size, shape, location or material of the contact member and the composition, durometer value and quantity of the encapsulating material, to be varied to accommodate a wide range of connector applications. The present connector 40 may also be configured to provide a relatively short electrical path. The connector 40 is capable of achieving a fine pitch that typically cannot be achieved by pin type connectors. The present connector 40 does not rely on the encapsulant as the sole means of support and does not require the connection members to be deformed in order to gain continuity with the circuit members 50, 52.
For conventional semiconductor device applications, the encapsulating material 46 provides a low initial insertion force in the range of about 10 grams to about 30 grams. The contact member provides a higher secondary insertion force in the range of about 40 grams to about 100 grams. The resulting electrical interconnection provides a higher long term force load toward the end of its engagement motion to ensure long term continuity without failure due to fatigue, compression set, or oxidation.
FIG. 4A illustrates an alternate connector 40A suitable for use with a solder ball device. FIG. 4B is a perspective view of the contact member 42A. The first circuit interface portion 62A is preferably configured for engagement with a ball grid array, such as shown on circuit member 50 of FIG. 2. Connector member 42A is retained in housing 44A by encapsulating material 46A. Distal end 70A is retained opposite end stop 72A and distal end 74A is retained opposite end stop 76A by encapsulating material 46A. FIGS. 5A and 5B illustrate an alternate connector 40B suitable for use with a solder ball device. The first circuit interface portions 62B of the contact member 42B are configured for engagement with a solder ball device at two locations. The two locations of the first circuit interface portions 62B preferably extend above the surface of the encapsulant 46B.
FIG. 6A is a side view of an alternate connector 90 according to the present invention particularly useful with a J-lead device 92 on a circuit member 94. Distal end 104 of contact member 96 is retained in a spaced relationship from end stop 106 on the housing 98 by encapsulating material 100. Similarly, distal end 108 of the contact member 96 is retained in a spaced relationship from the end stop 110 by encapsulating material 102. The contact member 96 is attached to housing 98 by encapsulating materials 100, 102. The encapsulating materials 100, 102 may be the same or different materials. For example, encapsulating material 100 may have a durometer value of about 25, while the material 102 has a durometer value of about 60.
When the J-lead device 92 is brought into engagement with the circuit interface portion 112 on the contact member 96, the distal ends 104, 108 initially move within the encapsulating material 100, 102, respectively, in a first mode of compliance. Again, deformation of the contact member 96 may provide a component of the first mode of compliance. Once the distal ends 104, 108 engage with the end stops 106, 110, respectively, the contact member 96 deforms within its elastic limit in a second mode of compliance. FIG. 6B is a perspective view of the contact member 96 of FIG. 6A.
FIG. 7A is a side sectional view of the present connector 120 for use as an edge card connector. The housing 122 forms a slot 124 for receiving an edge of a card 126 having at least one connector pad 128. A contact member 130 is positioned within an encapsulating material 132 so that a circuit interface portion 134 protrudes into the slot 124. The encapsulating material 132 retains distal end 136 of the contact member 130 in a spaced relationship with end stop 138. Similarly, the encapsulating material retains distal end 140 of the contact member 130 in a spaced relationship from end stop 142. FIG. 7B provides a perspective view of the contact member 130.
As the card 126 is inserted into the slot 124, the circuit interface portion 134 is brought into engagement with the contact 128. Deformation of the encapsulating material 132 and the contact member 130 provide a first mode of compliance whereby the distal end 136 moves toward the end stop 138. Similarly, as the second circuit interface portion 144 is brought into engagement with a connector member (not shown), the distal portion 140 moves in a first mode of compliance toward the end stop 142. Once the distal portions 136, 140 are engaged with the end stops 138, 142, respectively, the contact member 130 operates as a load spring in a second mode of compliance and deforms within its elastic range.
FIG. 8A is a side sectional view of a connector 150 according to the present invention for electrically connecting with a connector pad 152. A contact member 154 is retained within housing 156 by encapsulating material 158. The encapsulating material 158 retains distal end 160 of the contact member 154 in a spaced relationship from end stop 162. As the connector pad 152 is brought into engagement with the circuit interface portion 164 of the contact member 154, the distal end 160 is displaced in a first mode of compliance until it engages with the end stop 162. Deformation of the contact member 154 may provide a component of the first mode of compliance. A center portion 166 of the contact member 154 pivots on a portion 168 of the housing 156 so that engagement with the contact pad 152 causes the contact member 154 to rotate in a counterclockwise direction. Circuit interface portion 170 is similarly displaced when brought into engagement with a connector member (not shown). FIG. 8B is a perspective view of the contact member 154 of FIG. 8A. Once the distal end 160 engages with the end stop 162, the contact member 154 operates as a load spring and deforms within its elastic range.
FIG. 9A is an alternate connector 150A in which the contact member 154A has a shape designed to provide greater resistance in the second mode of compliance. In particular, the sharp point formed in the contact member 154A at the circuit interface portions 164A, 170A provides greater resistance to elastic deformation than the curved circuit interface portions 164, 170 illustrated in FIG. 8A. FIG. 9B is a perspective view of the contact member 154A of FIG. 9A.
FIG. 10A is a side sectional view of an alternate connector 150B according to the present invention. The contact member 154B has a shape intended to provide less resistance in the second mode of compliance than provided by the contact member 154 of FIG. 8A. Although the curvature of the circuit interface portions 164B, 170B corresponds generally to that shown in FIG. 8A, the inverted curvature of the contact member 154B provides for less resistance during the second mode of compliance, and hence a lower secondary insertion force.
FIG. 11A is a side sectional view of a connector 180 according to the present invention for engagement with a pin grid array device 182. Housing 184 has a slot 186 for receiving pin 188. Contact member 190 is positioned adjacent to slot 186. Distal ends 192, 194 of the contact member 190 are retained in a spaced configuration from end stops 196, 198, respectively, of the housing 184. FIG. 11B is a perspective view of the contact member 190.
FIG. 12A is a side sectional view of an alternate connector 200 according to the present invention. A contact member 202 is located in a housing 204. A first circuit interface portion 206 on the contact member 202 extends above a surface 208 of the housing 204. The second circuit interface portion 210 extends above a surface 209 of the housing 204. Alternately, the first and second interface portions 206, 210 may be recessed below the surfaces 208, 209, respectively. Resilient materials 212, 213 are interposed between the rigid connector member 202 and the housing 204 in two separate locations. The connector member 202 and resilient members 212, 213 are retained within the housing 204 by an encapsulating material 214.
The contact member 202 may be supported by one or more suspension filament 220, 227A, 227B to precisely locate the contact member 202 during encapsulation. The suspension filaments 220, 227A, 227B are preferably anchored to the housing 204 (see FIG. 13). The suspension filaments 220, 227A, 227B may be permanent or may be removed after application of the encapsulating material 214.
The suspension filaments 220, 227A, 227B may be a rigid material or a flexible material. The suspension filaments 220, 227A-227B are preferably flexible, but not extendible so as to permit limited translational and rotational movement of the contact member 202. The conductive elements 202 may be positioned along the filament 220 in such a way that a minimum of two moment arms are created as a result of the location of the interface point along the body of the contact member 202. A single rigid suspension member 220 may be located at a single point 221 near or along the major axis of the contact member 202 such that it provides a pivot point for rotation. Alternatively, second and/or third suspension filaments 227A, 227B may optionally be included (see FIGS. 19 and 20).
The filaments 220, 227A, 227B may be located at any point along the body of the contact member 202 such that it will be positioned in a desired location when the connector 200 is at rest, but will not be restricted from a desired amount of transitional or rotational movement. The suspension filaments 220, 227A, 227B may remain in place after encapsulation, and will result in a reinforced composite that will function in practice in a manner different from that of the encapsulant alone. The filaments 220, 227 will allow the desired motion of the contact member 202 upon incident with the opposing terminals that are to be connected, but will restrict movement in one or more directions as well as limit the total travel of the contact member 202, resulting in an action that will prevent damage to the encapsulant 214, the secondary resilient members 212, 213, the contact member 202, or the opposing terminal 216. The nature of contact member 202 action will allow for each member to move independent of its neighbor through a range sufficient to accommodate co-planarity variances between the conductive elements and any of the opposing terminals to be connected.
The contact member 202 is preferably rigid. As the connector member 216 on the first circuit member 218 is brought in contact with the first circuit interface portion 206, the encapsulating material 214 allows for both translational and rotational movement of the contact member 202 around a filament 220. Movement of the contact member 202 within the encapsulating material 214 comprises a first mode of compliance, resulting in a relatively low initial insertion force with a circuit members, such as 218. The compliant encapsulant 214 allows vertical movement until contact member 202 encounters one or both of the resilient materials 212, 213. The resilient materials 212, 213 in combination with the encapsulant 214 (and optionally the filaments 220, 227A, 227B) provide the second mode of compliance. In the preferred embodiment, the resilient materials 212, 213 are stiffer (higher durometer value) than the encapsulant 214, so that the secondary insertion force is larger than the initial insertion force. The contact member 202 eventually contacts end stops 222, 223 on the housing 204. Alternatively, the resilient materials 212, 213 may be selected so that the secondary insertion force is less than the initial insertion force.
The encapsulant 214 provides a relatively large range of motion at a low force, allowing for the contact 202 to achieve continuity and planarity despite a significant mismatch. In one embodiment, the filament 220 is not a rigid support, allowing for both rotational and translational movement of the contact 202. Once the contact member 202 is compressed against the resilient material 212, 213, the second mode of compliance provides long term connection that resists failure due to fatigue, vibration, temperature fluctuation, and excessive or repeated insertion. In an alternate embodiment in which the contact member 202 is flexible, the connector 200 will operate as a loading spring, as discussed above in connection with FIGS. 1-3.
FIG. 12B is a perspective view of a contact member 202 having an openings 221, 227 for receiving the filament 220. FIG. 12C illustrates an alternate connector 200A in which the opening 221A of the contact member 202A is a slot structure for receiving the filament 220A.
FIG. 13 is a perspective view of the connector 200 having a plurality of contact members 202 separated by spacers 224. The spacers may be incorporated into the filament 220. Alternatively, the contact members 202 may be retained in the desired spaced relationship during application of the encapsulating material 214 (see FIG. 12A). The filament 220 is supported by the housing 204. The spacing between the contact members 202 may be adjusted by altering the thickness of the spacers 224. The present connector is preferably capable of providing contact members having a pitch of less than about 0.4 mm, and more preferably less than about 0.2 mm. The spacers 224 may be constructed from a variety of dielectric materials, such as plastic or ceramics.
FIG. 14A is a side sectional view of an alternate connector 230 in which a cam-shaped contact member 232 is at least partially retained in a housing 234 by a filament 244. FIG. 14B is a perspective view of the contact member 232. A resilient material 238 is located adjacent to the contact member 232 on the side opposite encapsulating material 236. The housing 234 is configured for receiving a card edge device 240 having contact members 242 on at least one surface. As discussed in connection with FIG. 12A, the contact member 232 displaces the encapsulating material 236 in a first mode of compliance. Subsequently, the contact member 232 engages the resilient material 238 to initiate a second mode of compliance. The housing 234 is configured to limit the maximum rotation of the contact member 232 about the filament 244.
FIG. 15 is a side sectional view of an alternate connector 250 configured for engagement with a J-lead device 252 on a circuit member 254. The contact member 256 is positioned on a filament 258 adjacent to encapsulating material 260 and resilient material 262. The resilient material preferably has a higher durometer value than the encapsulating material 260.
FIG. 16A illustrates an alternate connector 270A for engagement with a solder ball device 272 on a circuit member 274. Connector element 276A rotates around pivot point 278A within connector housing 280A. The first circuit interface portion 282A of the contact member 276A includes a depression 284A to facilitate engagement with the ball member 272 of the circuit member 274. A second circuit interface portion 286A protrudes from the bottom of the housing 280A for engagement with a second circuit member (not shown). FIG. 16B is an alternate connector 270B in which the contact member 276B is in a generally vertical configuration for rotation around the pivot point 278B.
FIG. 17 is a side sectional view of an alternate connector 290 according to the present invention configured for engagement with a pin grid array device 292 having a pin 294. The contact member 296 rotates about pivot point 298 within the housing 300. Encapsulating material 302 provides a first mode of compliance and resilient material 304 provides a second mode of compliance.
FIG. 18 is a perspective view of a connector assembly 320 having an array of contact members 322. A template 324 with a plurality of slots 326 maintains the preferred spacing between the contact members 322. The connector assembly may be a wide variety of sizes and shapes.
FIG. 19 is a side sectional view of a pair of contact members 322 of FIG. 18, retained in the connector housing 328 by a pair of flexible filaments 330, 331 and an encapsulating material 332. A resilient material 334 is located adjacent to the contact member 322 in two locations. FIG. 20 illustrates the motion of the contact members 322 and filaments 330, 331 after engagement with a circuit member (not shown). The contact members 322 compress the resilient material 334. In addition to the rotational movement of the contact members 322, the translational movement of the contact members 322 is illustrated by the movement of the filaments 330 generally in a direction "A" toward the center of the connector 330. The filaments 331 move generally in a direction "B" away from the center of the connector 330.
Patents and patent applications disclosed herein, including those cited in the background of the invention, are hereby incorporated by reference. Other embodiments of the invention are possible. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
Claims
What is claimed is:
1. A connector apparatus for electrically connecting first and second circuit members, each circuit member having first and second operative surfaces with connector members, respectively, comprising: an electrically insulative connector housing adapted to be positioned substantially between the first and second circuit members; a resilient contact member positioned generally within the connector housing having resilient first and second circuit interface portions, the resilient contact member comprising a first compliant member; a resilient, dielectric encapsulating material surrounding a portion of the resilient contact member comprising a second compliant member, whereby the first and second compliant members are capable of providing a first mode of compliance when the contact member is displaced by a circuit member; and at least one end stop against which a portion of the second complaint material is at least partially compressed to provide a flexural point where the contact member elastically deforms in a second mode of compliance.
2. The apparatus of claim 1 wherein elastic deformation of the contact member and resilient encapsulating material comprises the first mode of compliance.
3. The apparatus of claim 1 wherein elastic deformation of the contact member comprises the second mode of compliance.
4. The apparatus of claim 1 wherein engagement of the contact member at the flexural point initiates the second mode of compliance.
5. The apparatus of claim 1 further comprising at least one support member supporting the contact member.
6. The apparatus of claim 5 wherein the support member comprises a pivot point around which the contact member rotates.
7. The apparatus of claim 5 wherein the support member comprises a flexible filament capable of permitting translational movement of the contact member.
8. The apparatus of claim 1 further comprising a plurality of contact members.
9. The apparatus of claim 1 comprising an opening in the housing extending between first and second surfaces for receiving the resilient contact member.
10. The apparatus of claim 1 wherein the first circuit interface portion of the resilient contact member extends above a first surface of the housing.
11. The apparatus of claim 1 wherein the first circuit interface portion of the resilient contact member extends below a first surface of the housing.
12. The apparatus of claim 1 wherein the second circuit interface portion of the resilient contact member extends above a second surface of the housing.
13. The apparatus of claim 1 wherein the second mode of compliance proximate the first circuit interface portion is generally equal to the second mode of compliance proximate the second circuit interface portion.
14. The apparatus of claim 1 wherein the second mode of compliance proximate the first circuit interface portion requires a greater insertion force than the second mode of compliance proximate the second circuit interface portion.
15. The apparatus of claim 1 wherein the first and second modes of compliance are within the elastic limits of the contact member.
16. The apparatus of claim 1 wherein the connector comprises an initial insertion force and a secondary insertion force with the circuit member.
17. The apparatus of claim 16 wherein the initial insertion force is less than the secondary insertion force.
18. The apparatus of claim 1 comprising first and second end stops on the housing defining flexural points where the second mode of compliance is initiated.
19. The apparatus of claim 1 wherein the resilient contact member comprises a curvilinear shape.
20. The apparatus of claim 1 wherein the first circuit interface portion comprises a shape complementary to a shape of the connector member.
21. The apparatus of claim 1 wherein the first circuit interface portion comprises a convex shape.
22. The apparatus of claim 21 wherein the convex shape is off-set from a first distal end of the contact member.
23. The apparatus of claim 1 herein the resilient contact member comprises a piece of a conductive sheet material.
24. The apparatus of claim 1 herein the resilient contact member comprises a piece of wire.
25. The apparatus of claim 1 wherein the first and second circuit interface portions provides a wiping engagement with an opposing connector member.
26. The apparatus of claim 1 wherein the connector comprises a configuration capable of maintaining the first operative surface parallel to the second operative surface.
27. The apparatus of claim 1 wherein the connector comprises a configuration capable of maintaining the first operative surface at a fixed angle relative to the second operative surface.
28. The apparatus of claim 1 wherein the first circuit member comprises a printed circuit board.
29. The apparatus of claim 1 wherein the first circuit member comprises an integrated circuit device.
30. The apparatus of claim 1 wherein the first circuit interface portion is capable of engaging with a connector member selected from the group consisting of a card edge, a j-lead device, a land grid array, a pin grid array, a flex circuit, a ribbon connector, a cable, and a ball grid array.
31. The apparatus of claim 1 further comprising a template having a plurality of slots for maintaining spacing between a plurality of contact members.
32. The apparatus of claim 1 wherein the housing further comprises an alignment mechanism for aligning the first and second circuit interface portions with the connector members on the first and second circuit members.
33. The apparatus of claim 1 wherein the first circuit interface portion comprises a cup-shape configured to engage with the connector member of a circuit member.
34. The apparatus of claim 1 wherein at least a portion of the second mode of compliance is determined by a geometry of the first contact member.
35. The apparatus of claim 1 wherein at least a portion of the second mode of compliance is determined by a thickness of the first contact member.
36. The apparatus of claim 1 wherein the contact member comprises at least one bend so that the first circuit interface portion is off-set from a distal end thereof.
37. The apparatus of claim 1 wherein the end stop comprises a flat surface on the housing.
38. A connector apparatus for electrically connecting first and second circuit members, each circuit member having first and second operative surfaces with connector members, respectively, comprising: an electrically insulative connector housing adapted to be positioned substantially between the first and second circuit members; a resilient contact member positioned generally within the connector housing having resilient first and second circuit interface portions, the resilient contact member comprising a first compliant member; a resilient, dielectric encapsulating material surrounding a portion of the resilient contact member comprising a second compliant member, whereby the first and second compliant members are capable of providing a first mode of compliance when the contact member is displaced by a circuit member; and at least one surface on the housing against which a portion of the second complaint material is at least partially compressed to provide a flexural point where the contact member elastically deforms in a second mode of compliance.
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